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Title:
CARBONATION OF CARPET ASH
Document Type and Number:
WIPO Patent Application WO/2016/044453
Kind Code:
A1
Abstract:
A method of recycling carpet ash may include providing a carpet ash mud including greater than or equal to about 1 % of a feed hydroxide based on the total solids content, adding water to the carpet ash mud to form a diluted stream, and carbonating the diluted stream to form a carbonate. A method of precipitating a carbonate composition may include providing a feed stream including a carpet ash and water, adding a hydroxide to the feed stream, and carbonating the feed stream to produce a precipitated carbonate composition. A method for facilitating precipitation of a carbonate composition may include adding a hydroxide to a carpet ash mud, and carbonating the carpet ash mud and the hydroxide to produce a precipitated carbonate composition. A precipitated carbonate composition may have a brightness less than or equal to about 65.

Inventors:
WICKS DOUGLAS (US)
PEREZ RICARDO M (US)
GOLBAYANI PARVIN (US)
Application Number:
PCT/US2015/050480
Publication Date:
March 24, 2016
Filing Date:
September 16, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
IMERYS PIGMENTS INC (US)
International Classes:
B02C23/00; B02C18/16
Foreign References:
US20120077890A12012-03-29
US5722603A1998-03-03
US7784719B12010-08-31
US20070264430A12007-11-15
US20120298010A12012-11-29
US20010023655A12001-09-27
US6129784A2000-10-10
US20130174517A12013-07-11
Attorney, Agent or Firm:
KENT, Christopher, T. (Henderson Farabow, Garrett & Dunner, L.L.P.,901 New York Avenue, N.W, Washington DC, US)
Download PDF:
Claims:
WH JS CLA!MEDjS;

1. A method of recycling carpet ash, the method comprising:

providing a carpet ash mud comprising greater than or equal to about 1 % of a feed hydroxide based on the total solids content;

adding water to the carpet ash mud to form a diluted stream; and

carbonating the diluted stream to form a carbonate.

2. The method of claim 1 , wherein the carpet ash mud has a solids content greater than 35% by weight based on the total weight of the carpet ash mud.

3. The method of claim 1 , wherein the carpet ash mud comprises greater than 86.5% of the feed hydroxide, a feed oxide, or a combination thereof, based on the total solids content.

4. The method of claim 1 , wherein the feed hydroxide comprises calcium hydroxide (Ca(OH)2).

5. The method of claim 1 , wherein the diluted stream has a solids content less than 15% by weight based on the total weight of the diluted stream,

8. The method of claim 1 , wherein the diluted stream has a solids content greater than 35% by weight based on the total weight of the diluted stream.

7. The method of claim 1 , further comprising quenching a carpet ash with water vapor to form the carpet ash mud.

8. The method of claim 1 , further comprising adding a second hydroxide to the diluted stream,

9. The method of claim 8, wherein the second hydroxide forms a carbonate on at least a portion of the surface of a component of the carpet ash mud,

10. The method of claim 8, wherein the feed hydroxide is the same

composition as the second hydroxide.

1 1. The method of claim 8, wherein the component the carpet ash mud is selected from the group consisting of calcium oxide (CaO), alumina (A!203), magnesium oxide (MgO), and silica (Si02).

12. The method of claim 1 , wherein the carbonating comprises adding an exhaust gas to the diluted stream.

13. The method of claim 1 , wherein the carbonate comprises a low-brightness carbonate.

14. The method of claim 13, wherein the low-brightness carbonate has a brightness less than or equal to about 20.

15. A precipitated carbonate composition having a brightness less than or equal to about 65.

16. The precipitated carbonate composition of claim 15 having a brightness less than or equal to about 40.

17. The precipitated carbonate composition of claim 15, wherein the precipitated carbonate composition is a recovered precipitated carbonate composition,

18. The precipitated carbonate composition of claim 15, wherein the precipitated carbonate composition comprises a precipitated calcium carbonate (PCC).

19. The precipitated carbonate composition of claim 15, wherein the precipitated calcium carbonate composition comprises inorganic impurities selected from the group consisting of magnesium, aluminum, and silicon.

20. The precipitated carbonate composition of claim 15, wherein the precipitated carbonate has a median particle size (dso) in the range from about 5 microns to about 15 microns.

21. The precipitated carbonate composition of claim 15, wherein the precipitated carbonate composition comprises greater than or equal to about 90% calcium carbonate (CaC03).

22. The precipitated carbonate composition of claim 15, wherein the precipitated carbonate composition has a BET surface area greater than or equal to about 1.7 m2/g.

23. The precipitated carbonate composition of claim 15, wherein the precipitated carbonate composition comprises a carbonate component and a second component different from the carbonate component.

24. A method of precipitating a carbonate composition, the method comprising:

providing a feed stream comprising a carpet ash and water;

adding a hydroxide to the feed stream; and

carbonating the feed stream to produce a precipitated carbonate composition.

25. The method of claim 24, wherein the precipitated carbonate composition comprises a carbonate component and a second component different from the carbonate component.

26. The method of claim 25, wherein the second component comprises a second carbonate component.

27. The method of claim 25, wherein the second component comprises a non- carbonate component.

28. The method of claim 25, wherein the second component comprises an oxide component.

29. The method of claim 24, wherein the precipitated carbonate composition comprises a carbonate component bound to at least a portion of a surface of a second component of the precipitated carbonate composition.

30. The method of claim 24, wherein the precipitated carbonate composition comprises a carbonate component enclosing substantially all of the surface of a second component of the precipitated carbonate composition,

31. The method of claim 24, wherein the precipitated carbonate composition comprises a carbonate component, a second component, and an snterfacial component.

32. The method of claim 31 , wherein the snterfacial component has a chemical composition containing elements of the carbonate component and the second

component.

33. The method of c!aim 24, wherein adding the hydroxide facilitates precipitation of the precipitated carbonate composition.

34. A method for facilitating precipitation of a carbonate composition, the method comprising:

adding a hydroxide to a carpet ash mud; and

carbonating the carpet ash mud and the hydroxide to produce a precipitated carbonate composition.

35. The method of claim 34, wherein the carpet ash mud comprises a feed hydroxide,

36. The method of claim 35, wherein the feed hydroxide produces a second precipitated carbonate different from the precipitated carbonate composition.

37. The method of claim 34, further comprising adding water to the carpet ash mud prior to adding the hydroxide,

38. The method of claim 37, wherein the water reacts with an oxide of the carpet ash mud to form an inorganic hydroxide similar to the hydroxide.

39. The method of claim 34, wherein the precipitated carbonate comprises a low-brightness carbonate.

40. The method of claim 34, wherein the precipitated carbonate composition comprises a carbonate component bound to at least a portion of a surface of a component of the carpet ash mud.

41. The method of claim 34, wherein the precipitated carbonate composition comprises a carbonate component enclosing at least part of the surface area of a component of the carpet ash mud.

42. The method of claim 34, wherein the precipitated carbonate composition comprises a carbonate component enclosing substantially ail of the surface of a component of the carpet ash mud.

43. The method of claim 34, wherein the precipitated carbonate composition treats a surface of a component of the carpet ash mud.

44. The method of claim 43, wherein the treated surface comprises a carbonate on the surface of the component of the carpet ash mud.

45. The method of claim 34, wherein the precipitated carbonate composition comprises a carbonate component physically bound to the surface of a component of the carpet ash mud.

46. The method of claim 34, wherein the precipitated carbonate composition comprises a carbonate component chemicaily bound to the surface of a component of the carpet ash mud.

Description:
[0001] This PCT International Application claims the benefit of priority of U.S. Provisional Patent Application Nos. 62/051 ,621 , filed September 17, 2014, and

82/074,276, filed November 3, 2014, the subject matter of both of which is incorporated herein by reference in their entireties.

FIELD OF fSCLOSURE

[0002] This disclosure relates to methods and systems for carbonation of carpet ash, for example, to produce carbonates. This disclosure also relates to facilitating precipitation of carbonates by treating a component of carpet ash.

[0003] Carpet construction may contain various fiber types that are tufted into a carpet backing. The backing may be incorporated as a backcoating into the carpet to provide structure. Carpet backings and backcoatings may contain various polymers and fillers, such as SBR, EVA, PET, PVC, carbonate, clay, and glass. To create the carpet, the carpet face is woven through a backing fabric and held in place by an adhesive, which may be a latex polymer or thermoresin including fillers, such as calcium carbonate or other mineral filler materials.

[0004] Carpet backing is generally believed to have little value as a recycled or reclaimed material. Carpet backing makes up about 50% of the weight of whole carpet. Wet and dirty carpet in post-consumer applications, such as during demolition, remodeling, refurbishing, or retrofitting, is also considered to have little value because the fibers may not be recoverable. Carpet is also bulky, heavy, difficult to handle, and difficult to ship. During the manufacturing process or in post-consumer applications, waste materials may be incinerated or thrown out in landfills. The waste materials may include carpet fibers, excess carpet backing, pieces of whole carpet, carpet from demolition, or excess carpet from cutting and manufacturing.

[0005] However, given the high proportion of inorganic minerals in carpet backing and a desire to reduce manufacturing cost and to improve the sustainabslity of carpet manufacturing, there is a desire in the industry to recover carpet materials, such as fillers, at relatively low cost, relatively high efficiency, or both.

[0008] Therefore, it may be desirable to provide a process for recovering a carbonate from carpet or carpet backing. It may be further desirable to recover carbonates from carpet. It may also be desirable to provide a process for improving the efficiency of a carbonate recovery process. It may also be desirable to facilitate precipitation of carbonates in a recovery process.

SUMMARY OF THE DISCLOSURE

[0007] In the following description, certain aspects and embodiments will become evident. It should be understood that the aspects and embodiments, in their broadest sense, could be practiced without having one or more features of these aspects or embodiments.

[0008] According to a first aspect, a method of recycling carpet ash may include providing a carpet ash mud that may include greater than or equal to about 1 % of a feed hydroxide based on the total solids content. The method may also include adding water to the carpet ash mud to form a diluted stream. The method may also include carbonatlng the diluted stream to form a carbonate.

[0009] According to another aspect, a method of precipitating a carbonate composition may include providing a feed stream comprising a carpet ash and water. The method may also include adding a hydroxide to the feed stream. The method may also include carbonating the feed stream to produce a precipitated carbonate

composition.

[0010] According to a further aspect, a precipitated carbonate composition may have a brightness less than or equal to about 65.

[0011] According to another aspect, a method for facilitating precipitation of a carbonate composition may include adding a hydroxide to a carpet ash mud. The method may also include carbonating the carpet ash mud and the hydroxide to produce a precipitated carbonate composition.

[0012] According to yet another aspect, a method for producing a recycled filler from carpet may include providing a feed stream that may include a carpet ash mud that may have greater than or equal to about 1 % of a feed hydroxide based on the total solids content. The method may also include carbonating the carpet ash mud to form a recovered carbonate composition.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 shows an exemplary system in an exemplary embodiment of a process for recovering or precipitating a carbonate.

[0014] FIG. 2 shows exemplary steps in an exemplary embodiment of a process for recovering or precipitating a carbonate. [0015] Reference will now be made in detail to exemplary embodiments. It should be understood that these embodiments are merely exemplary. Although certain embodiments may be discussed in terms of calcium oxide, calcium hydroxide, and calcium carbonate, it is understood that the discussion is used merely to facilitate understanding, and that other oxides, hydroxides, or carbonates could be used in conjunction with the processes describe herein, including, for example, other mineral oxides, hydroxides, or carbonates, or other alkali earth metal oxides, hydroxides, or carbonates.

[0016] As described herein, unless otherwise specified, a content percentage of a chemical composition may be measured using x-ray fluorescence (XRF), using a an XRF spectrophotometer model Bruger Tiger S-8.

[0017] According to some embodiments, a method of recycling carpet ash may include providing a carpet ash mud that may include greater than or equal to about 1 % of a feed hydroxide based on the total solids content. The method may also include adding water to the carpet ash mud to form a diluted stream. The method may also include carbonating the diluted stream to form a carbonate.

[0018] According to some embodiments, "carbonating" and "carbonation" may be referred to as "carbonatating" and "carbonatation." .

[0019] According to some embodiments, the carpet ash mud may have a solids content greater than 35% by weight based on the total weight of the carpet ash mud. For example, the carpet ash mud may include greater than or equal to about 40% by weight, greater than or equal to about 50% by weight, greater than or equal to about 60% by weight, greater than or equal to about 85% by weight, greater than or equal to about 70% by weight, greater than or equal to about 75% by weight, or greater than or equal to about 80% by weight of the carpet ash mud.

[0020] According to some embodiments, the carpet ash mud may have a solids content in a range from about 35% to about 90% by weight based on the total weight of the carpet ash mud, such as, for example, in a range from about 40% to about 80% by weight, or in a range from about 80% to about 75% by weight based on the total weight of the carpet ash mud.

[0021] According to some embodiments, the carpet ash mud may include the feed hydroxide and an oxide. According to some embodiments, the carpet ash mud may include greater than 86.5% of the feed hydroxide, a feed oxide, or a combination thereof, based on the total solids content. For example, the carpet ash mud may include greater than or equal to about 88%, greater than or equal to about 90%, greater than or equal to about 92%, greater than or equal to about 93%, greater than or equal to about 94%, greater than or equal to about 95%, or greater than or equal to about 96% of the feed hydroxide, a feed oxide, or a combination thereof, based on the solids content. According to some embodiments, the feed hydroxide and the feed oxide may be a mineral hydroxide and a mineral oxide with the same positively charged

component. For example, the hydroxide may be Ca(OH) 2 and the oxide may be (CaO).

[0022] According to some embodiments, the carpet ash mud may include greater than or equal to about 15% of a combination of the feed hydroxide and an oxide based on the total solids content, such as, for example, greater than or equal to about 20%, greater than or equal to about 30%, greater than or equal to about 35%, greater than or equal to about 40%, greater than or equal to about 50%, greater than or equal to about 60%, greater than or equal to about 70%, greater than or equal to about 75%, greater than or equal to about 80%, greater than or equal to about 85%, greater than or equal to about 90%, greater than or equal to about 92%, greater than or equal to about 93%, greater than or equal to about 94%, greater than or equal to about 95%, or greater than or equal to about 96% of a combination of the oxide and a feed hydroxide based on the total solids content,

[0023] According to some embodiments, the diluted stream may have a solids content in a range from about 5% to about 30% by weight based on the total weight of the diluted stream. For example, the diluted stream may have a solids content in a range from about 5% to about 25% by weight, from about 5% to about 15% by weight, from about 10% to about 25% by weight, from about 10% to about 20% by weight, from about 10% to about 15% by weight, from about 15% to about 25% by weight, or from about 20% to about 25% by weight based on the total weight of the diluted stream.

[0024] According to some embodiments, the diluted stream may have a solids content less than 15% by weight based on the total weight of the diluted stream, such as, for example, less than or equal to about 14% by weight, less than or equal to about 13.5% by weight, less than or equal to about 13% by weight, less than or equal to about 12% by weight, less than or equal to about 1 1 % by weight, less than or equal to about 10% by weight, or less than or equal to about 8% by weight based on the total weight of the diluted stream.

[0025] According to some embodiments, the diluted stream may have a solids content greater than 35% by weight based on the total weight of the diluted stream, such as, for example, greater than or equal to about 37% by weight, greater than or equal to about 40% by weight, greater than or equal to about 43% by weight, greater than or equal to about 45% by weight, or greater than or equal to about 50% by weight based on the total weight of the diluted stream.

[0028] According to some embodiments, the method may include quenching a carpet ash with water vapor to form the carpet ash mud. According to some

embodiments, quenching the carpet ash may include adding steam to form the carpet ash mud.

[0027] According to some embodiments, water may be added to the carpet ash in a sufficient amount to form calcium hydroxide (Ca(OH)2) from calcium oxide (CaO). According to some embodiments, calcium hydroxide may be formed from the calcium oxide by dry slaking. According to some embodiments, the amount of wafer may be sufficient to form greater than 0% calcium hydroxide, greater than or equal to about 10% calcium hydroxide, greater than or equal to about 20% calcium hydroxide, greater than or equal to about 30% calcium hydroxide, greater than or equal to about 40% calcium hydroxide, greater than or equal to about 50% calcium hydroxide, greater than or equal to about 60% calcium hydroxide, greater than or equal to about 70% calcium hydroxide, greater than or equal to about 75% calcium hydroxide, greater than or equal to about 80% calcium hydroxide, greater than or equal to about 85% calcium hydroxide, greater than or equal to about 90% calcium hydroxide, greater than or equal to about 95% calcium hydroxide, greater than or equal to about 97% calcium hydroxide, greater than or equal to about 98% calcium hydroxide, or greater than or equal to about 99% calcium hydroxide. According to some embodiments, the amount of water may be sufficient to form about 100% calcium hydroxide, or to convert substantially all of the calcium oxide to calcium hydroxide. According to some embodiments, the calcium hydroxide may be formed as a powder or particulate form of calcium hydroxide.

According to some embodiments, water may be added by adding steam to the carpet ash to form the calcium hydroxide. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, to form at least part of the carpet ash mud. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, for example, prior to carbonating. According to some embodiments, carpet ash (for example, from a boiler or incinerator) may be combined with steam in a sufficient amount to convert about 100% of the calcium oxide to calcium hydroxide, such that the calcium hydroxide remains in a powder or particulate form, and the powder or particulate calcium hydroxide may then be combined with water.

[0028] Adding the water to the carpet ash mud may include adding steam to the carpet ash mud.

[0029] According to some embodiments, the carpet ash mud may have been formed from incinerated carpet, waste carpet, post-consumer carpet, or carpet backing.

[0030] According to some embodiments, the feed hydroxide may include a mineral hydroxide, such as, for example, an alkali earth metal hydroxide. The feed hydroxide may include calcium hydroxide (Ca(OH) 2 ). The carbonate may include a mineral carbonate, such as, for example, an alkali earth metal carbonate. The carbonate may include calcium carbonate (CaC0 3 ). [0031] According to some embodiments, the carpet ash mud may include greater than or equal to about 5% of the feed hydroxide based on the total solids content, such as, for example, greater than or equal to about 10% of the feed hydroxide, greater than or equal to about 15% of the feed hydroxide, or greater than or equal to about 20% of the feed hydroxide based on the total solids content. According to some embodiments, the carpet ash mud may include the feed hydroxide in a range from about 1 % to about 20% based on the total solids content, such as, for example, in a range from about 1 % to about 10%, from about 5% to about 15%, from about 10% to about 15%, from about 5% to about 10%, from about 1 % to about 5% based on the total solids content.

[0032] According to some embodiments, the carpet ash mud may include an oxide. According to some embodiments, the oxide may include a mineral oxide, such as, for example, an alkali earth metal oxide. The oxide may include at least one of calcium oxide (CaO), magnesium oxide (MgO), silica (Si0 2 ), alumina (AI2O3),

phosphorous pentoxide {P2O5), iron oxide (e.g., Fe 2 03), or sulfur as S0 3 . According to some embodiments, the carpet ash mud may include greater than or equal to about 10% of the oxide based on the total solids content, such as, for example, greater than or equal to about 15%, greater than or equal to about 20%, greater than or equal to about 25%, or greater than or equal to about 30% of the oxide based on the total solids content. According to some embodiments, the carpet ash mud may include the oxide in a range from about 1 % to about 30% based on the total solids content, such as, for example, from about 1 % to about 25%, from about 1 % to about 20%, from about 1 % to about 15%, from about 5% to about 25%, from about 10% to about 25%, from about 15% to about 25%, from about 15% to about 25%, from about 5% to about 20%, or from about 10% to about 20% based on the total solids content.

[0033] According to some embodiments, the carpet ash mud may include less than or equal to about 86% of a carbonate composition based on the total solids content, such as, for example, less than or equal to about 75%, less than or equal to about 60%, less than or equal to about 50%, less than or equal to about 30%, less than or equal to about 25%, less than or equal to about 10%, less than or equal to about 9%, less than or equal to about 8%, less than or equal to about 7%, less than or equal to about 8%, less than or equal to about 5%, or less than or equal to about 4% of a carbonate composition based on the total solids content.

[0034] According to some embodiments, the carbonating may include adding an exhaust gas to the diluted stream. According to some embodiments, the carbonating may include adding a carbon dioxide-containing gas to the diluted stream. Adding the carbon dioxide-containing gas may include adding an exhaust gas, such as a flue gas, to the diluted stream. The carbon dioxide-containing gas may include a gaseous mixture of carbon dioxide and air. The carbon dioxide may be produced by capturing or sequestering carbon dioxide from another gas, such as, for example, from an exhaust gas or flue gas. The carbonating may occur in a reactor vessel.

[0035] According to some embodiments, the carbonate may include a low- brightness carbonate. Brightness, when used in this disclosure, refers to a Hunter brightness, as specified in the procedures set forth by HunterLab and using a

Technidyne Color Touch II Brightness meter. Approximately 5 to 10 grams of dry recovered ash is pressed into a tablet at 120 pound pressure and measured. The low- brightness carbonate may have a brightness less than or equal to about 65, such as, for example, less than or equal to about 80, less than or equal to about 50, less than or equal to about 40, less than or equal to about 30, less than or equal to about 25, less than or equal to about 20, less than or equal to about 19. less than or equal to about 18, less than or equal to about 17, less than or equal to about 16, less than or equal to about 15, or less than or equal to about 14.

[0038] According to some embodiments, the carbonate may have a loss on ignition (LOI) of greater than or equal to 40% by weight, such as, for example, greater than or equal to 50% by weight, or greater than or equal to 55% by weight. According to some embodiments, the carbonate may have a LOI in a range from about 40% to about 60% by weight, such as, for example, from about 40% to about 50% by weight, from about 45% to about 55% by weight, or from about 50% to about 80% by weight.

[0037] According to some embodiments, the carbonate may include a precipitated calcium carbonate (PCC).

[0038] According to some embodiments, the carbonate may have a median particle size (d 5 o) in the range from about 5 microns to about 15 microns. For example, the carbonate may have a median particle size in the range from about 5 microns to about 10 microns, or from about 7 microns to about 10 microns. Median particle size (d 5 o) describes a property of the particles, where 50% of the particles have an

equivalent spherical diameter less than or equal to the stated value. The median particle size may be determined by a Sedigraph Model 5120 IN Particle Size Analyzer, as supplied by Micromerefics. The Sedigraph analysis determines particle size based on the distribution of particles using a laser light scattering and sedimentation technique.

[0039] According to some embodiments, the carbonate may have a BET surface area greater than or equal to about 1.7 m 2 /g. For example, the carbonate may have a BET surface area greater than or equal to about 1.8 m 2 /g, greater than or equal to about 1.9 m 2 /g, greater than or equal to about 2.0 m 2 /g, greater than or equal to about 2.1 m 2 /g, greater than or equal to about 2.2 m /g, greater than or equal to about 2,3 m 2 /g, greater than or equal to about 2.4 m 2 /g, greater than or equal to about

2.5 m 2 /g. greater than or equal to about 2.6 m 2 /g, greater than or equal to about

2,7 m 2 /g, greater than or equal to about 3.0 m /g, greater than or equal to about

4.0 m 2 /g, greater than or equal to about 5,0 m 2 /g, greater than or equal to about

6.0 m 2 /g, greater than or equal to about 7.0 m /g, greater than or equal to about

8.0 m 2 /g, greater than or equal to about 9.0 m 2 /g, greater than or equal to about

10.0 rn 2 /g.

[0040] According to some embodiments, the carbonate may include greater than or equal to about 87% CaC0 3 , such as, for example, greater than or equal to about 90% CaC0 3 , greater than or equal to about 91 % CaC0 3 , greater than or equal to about 92% CaC0 3 , greater than or equal to about 93% CaC0 3 , greater than or equal to about 94% CaC0 3 , greater than or equal to about 95% CaC0 3 , or greater than or equal to about 98% CaC0 3 .

[0041] According to some embodiments, the method may also include adding a second hydroxide. Adding the second hydroxide may include adding a slurry containing the second hydroxide to the diluted stream. The second hydroxide may be added, for example, to the diluted stream or to the carpet ash mud. According to some embodiments, the second hydroxide may form a precipitated carbonate composition in the carbonating step. According to some embodiments, the precipitated carbonate composition may include a carbonate component and a second component.

[0042] According to some embodiments, the second hydroxide may form a carbonate. For example, the carbonate may be precipitated onto at least a portion of the surface of a component of the carpet ash mud. According to some embodiments, the carbonate may treat substantially all of the surface area of the component of the carpet ash mud. According to some embodiments, the component may include at least one of calcium oxide (CaO), alumina (AI 2 O 3 ), magnesium oxide (MgO), phosphorous pentoxsde (P2O5), iron oxide (e.g., FeaOa), sulfur as S0 3l or silica (Si0 2 ).

[0043] According to some embodiments, the feed hydroxide may be the same composition as the second hydroxide.

[0044] According to some embodiments, a method of precipitating a carbonate composition may include providing a feed stream comprising a carpet ash and water. The method may also include adding a hydroxide to the feed stream. The method may also include carbonating the feed stream to produce a precipitated carbonate

composition.

[0045] According to some embodiments, the adding the hydroxide may include adding a slurry containing the hydroxide to the feed stream. According to some embodiments, the feed stream may be diluted, for example, with water, prior to adding the slurry containing the hydroxide. [0046] According to some embodiments, the precipitated carbonate composition may include a carbonate component that may coat, encapsulate, react with, or bond, either physically or chemically, with at least a portion of the surface of a component of the carpet ash mud. For example, the carbonate component may adsorb to at least a portion of the surface of the component. According to some embodiments, the carbonate component may physically react with or attach to at least a portion of the component, such as, for example, through physisorption. According to some

embodiments, the carbonate component may chemically bond with the surface of the component, such as, for example, through ionic or van der Waals bonds. According to some embodiments, the carbonate component may coat or encapsulate substantially all of the surface of the component, such as, for example, by forming a carbonate layer over at least part of, a majority of, or substantially all of the surface area of the component.

[0047] According to some embodiments, the precipitated carbonate

composition may include a multi-component composition. The precipitated carbonate composition may include a carbonate component and a second component different from the carbonate component.

[0048] According to some embodiments, the carbonate component may include, for example, CaC0 3 or IVIgCOa. According to some embodiments, the carbonate component may include a carbonate phase. The carbonate phase may include a calcium carbonate phase, such as, for example, a calcite phase, an aragonite phase, or a combination thereof. The carbonate phase may, according to some embodiments, include a magnesium carbonate phase, such as, for example, a triclinic phase.

[0049] According to some embodiments, the second component may include a phase different from the carbonate component. For example, the second component may include a non-carbonate component, such as, for example, an oxide. The oxide, may include, for example, calcium oxide (CaO), magnesium oxide (MgO), silica (S1O2), alumina (AI2O3), phosphorous pentoxide (P2O5), iron oxide (e.g., FeaOa), sulfur as S0 3 , or any combination thereof. According to some embodiments, the second component may include a second carbonate component. For example, when the carbonate component is CaC0 3 , the second component may include MgC0 3 . According to some embodiments, the second component may include a different phase from the carbonate component. For example, the carbonate component may include a calcite phase and the second component may include a triclinic phase, a cristobalite phase, or an amorphous phase (e.g., amorphous silica).

[0050] According to some embodiments, the precipitated carbonate

composition may include a carbonate component bound to at least a portion of a surface of a second component of the precipitated carbonate composition. For example, the carbonate component may be chemically bound to the second

component, such as through ionic, coordinate covalent (dative), or van der Waals bonds. According to some embodiments, the carbonate component may physically bond or attach to the second component. According to some embodiments, the carbonate component may be adsorbed or physisorbed to the second component.

According to some embodiments, the carbonate component may form a carbonate layer over the second component during the carbonating step. For example, the carbonate component may form a carbonate layer, shell, or coating that covers at least a portion of, a majority of, or substantially all of the second component. According to some embodiments, the carbonate component may coat, enclose, or encapsulate

substantially all of the second component. According to some embodiments, the second component may include a component of a carpet ash or carpet ash mud.

[0051] According to some embodiments, the precipitated carbonate

composition may include a carbonate component, a second component, and/or an interfacial component. The interfacial component may be, for example, a boundary region between the carbonate component and the second component. The interfacial component may include a chemical composition containing elements of the carbonate component and the second component. For example, when the precipitated carbonate composition includes a calcium carbonate as the carbonate component and a magnesium carbonate as the second component, an interfacial region may include calcium and/or magnesium diffusing into the other component, or a region containing a mixture of calcium carbonate and magnesium carbonate. An interfacial region may occur, for example, upon thermal treatment of the precipitated carbonate composition.

[0052] According to some embodiments, adding the hydroxide may facilitate additional precipitation (e.g., improved yield) of the precipitated carbonate composition. For example, the hydroxide may form a carbonate that treats at least a portion of the surface of the component of the feed stream, such as an oxide in carpet ash mud. During the carbonating, the hydroxide may react with, for example, carbon dioxide to form a carbonate that precipitates from a solution. The precipitate may include both the carbonate and the component from the feed stream. By way of example, if the carbonate treats a magnesium oxide, the precipitated carbonate composition may include both a calcium carbonate component and a magnesium oxide component.

[0053] According to some embodiments, the feed stream may include a carpet ash mud. The carpet ash mud may be formed by quenching a carpet ash with water vapor to form the carpet ash mud. According to some embodiments, quenching the carpet ash may include adding steam to the carpet ash to form the carpet ash mud. The carpet ash may have been formed from incinerated waste carpet, post-consumer carpet, or carpet backing.

[0054] According to some embodiments, water may added be to the carpet ash in a sufficient amount to form calcium hydroxide (Ca(OH) 2 ) from calcium oxide (CaO). According to some embodiments, calcium hydroxide may be formed from the calcium oxide by dry slaking. According to some embodiments, the amount of water may be sufficient to form greater than 0% calcium hydroxide, greater than or equal to about 10% calcium hydroxide, greater than or equal to about 20% calcium hydroxide, greater than or equal to about 30% calcium hydroxide, greater than or equal to about 40% calcium hydroxide, greater than or equal to about 50% calcium hydroxide, greater than or equal to about 60% calcium hydroxide, greater than or equal to about 70% calcium hydroxide, greater than or equal to about 75% calcium hydroxide, greater than or equal to about 80% calcium hydroxide, greater than or equal to about 85% calcium hydroxide, greater than or equal to about 90% calcium hydroxide, greater than or equal to about 95% calcium hydroxide, greater than or equal to about 97% calcium hydroxide, greater than or equal to about 98% calcium hydroxide, or greater than or equal to about 99% calcium hydroxide. According to some embodiments, the amount of water may be sufficient to form about 100% calcium hydroxide, or to convert substantially all of the calcium oxide to calcium hydroxide. According to some embodiments, the calcium hydroxide may be formed as a powder or particulate form of calcium hydroxide.

According to some embodiments, water may be added by adding steam to the carpet ash to form the calcium hydroxide. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, to form at least part of the carpet ash mud. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, for example, prior to carbonating. According to some embodiments, carpet ash (for example, from a boiler or incinerator) may be combined with steam in a sufficient amount to convert about 100% of the calcium oxide to calcium hydroxide, such that the calcium hydroxide remains in a powder or particulate form, and the powder or particulate calcium hydroxide may then be combined with water.

[0055] According to some embodiments, the precipitated carbonate

composition may be a recovered precipitated carbonate. According to some

embodiments, the recovered precipitated carbonate may be recovered from carpet, such as, for example, from the carpet ash or the carpet ash mud.

[0056] According to some embodiments, the feed stream may have a solids content in a range from about 35% to about 90% by weight based on the total weight of the feed stream, such as, for example, in a range from about 40% to about 80% by weight, or in a range from about 60% to about 75% by weight based on the total weight of the feed stream.

[0057] According to some embodiments, the stream may include greater than or equal to about 1 % of a feed hydroxide based on the total solids content, such as, for example, greater than or equal to about 5% of the feed hydroxide, greater than or equal to about 10% of the feed hydroxide, greater than or equal to about 15% of the feed hydroxide, or greater than or equal to about 20% of the feed hydroxide based on the total solids content. For instance, the carpet ash mud may include the feed hydroxide in a range from about 20% to about 88.5% based on the total solids content, such as, for example, in a range from about 50% to about 85%, from about 50% to about 75% based on the total solids content. According to some embodiments, the feed stream may include a feed hydroxide in a range from about 1 % to about 20% based on the total solids content, such as, for example, in a range from about 1 % to about 10%, from about 5% to about 15%, from about 10% to about 15%, from about 5% to about 10%, from about 1 % to about 5% based on the total solids content.

[0058] According to some embodiments, the feed material may include an oxide. For example, the oxide may be a component of the carpet ash. According to some embodiments, the oxide may include a mineral oxide, such as, for example, an alkali earth metal oxide. The oxide may include calcium oxide (CaO), magnesium oxide (MgO), phosphorous pentoxide (P2O5), iron oxide (e.g., Fe 2 0 3 ), or sulfur as S0 3 .

According to some embodiments, the feed material may include greater than or equal to about 5% of the oxide based on the total solids content, such as, for example, greater than or equal to about 10%, greater than or equal to about 15%, greater than or equal to about 20%, greater than or equal to about 25%, greater than or equal to about 30%, greater than or equal to about 40%, greater than or equal to about 50%, greater than or equal to about 60%, greater than or equal to about 70%, greater than or equal to about 80%, or greater than or equal to about 90% of the oxide based on the total solids content. According to some embodiments, the feed material may include an oxide in a range from about 1 % to about 90% based on the total solids content, such as, for example, in a range from about 10% to about 50%, from about 20% to about 80%, from about 30% to about 80%, from about 20% to about 40%, from about 1 % to about 30%, from about 1 % to about 10%, from about 40% to about 80%, from about 80% to about 80%, or from about 70% to about 90%, based on the total solids content.

[0059] According to some embodiments, the method may include adding water to the feed stream prior to adding the hydroxide. The water may react with an oxide of the feed stream to form an inorganic hydroxide similar to the added hydroxide. For example, according to some embodiments, Ca(OH) 2 may be added to the feed stream, and CaO in the carpet ash may react with the added wafer to form Ca(OH) 2 . According to some embodiments, adding the wafer to the feed stream may include adding steam to the feed stream.

[0060] According to some embodiments, carbonating the feed stream may include adding a carbon dioxide-containing gas. Adding the carbon dioxide-containing gas may include adding an exhaust gas, such as, for example, a flue gas. The carbon dioxide-containing gas may include a gaseous mixture of carbon dioxide and air. The carbon dioxide may be produced by capturing or sequestering carbon dioxide from another gas, such as, for example, from an exhaust gas or flue gas. [0081] According to some embodiments, the precipitated carbonate composition may include a low-brightness carbonate. For example, the low-brightness carbonate may have a brightness less than or equal to about 65, such as, for example, less than or equal to about 80, less than or equal to about 50, less than or equal to about 40, less than or equal to about 30, less than or equal to about 25, less than or equal to about 20, less than or equal to about 19, less than or equal to about 18, less than or equal to about 17, less than or equal to about 16, less than or equal to about 15, or less than or equal to about 14. According to some embodiments, the method may include thermally treating the low-brightness carbonate to produce a high-brightness carbonate.

[0082] According to some embodiments, the precipitated carbonate

composition may be a precipitated calcium carbonate (PCC). The PCC may include, in some embodiments, inorganic impurities, such as, for example, impurities of

magnesium, aluminum, and/or silicon. For example, magnesium impurities may result from MgO that may have been treated a carbonate formed from Ca(OH) 2 . When the Ca(OH) 2 is carbonated, the Ca(OH) 2 may form CaC0 3 , and the MgO may create Mg- based impurities in the CaC0 3 . Similar PCCs resulting from the added hydroxide may include silicon- or silica-based impurities, aluminum- or alumina-based impurities, or calcium-based impurities, that may develop from, for example, Si0 2 , Al 2 0 3 , or CaO in the feed stream, respectively.

[0063] According to some embodiments, the precipitated carbonate

composition may have a loss on ignition (LOI) of greater than or equal to 40% by weight, such as, for example, greater than or equal to 50% by weight or greater than or equal to 55% by weight. According to some embodiments, the precipitated carbonate composition may have a LOI in a range from about 40% to " about 60% by weight, such as, for example, from about 40% to about 50% by weight, from about 45%o to about 55% by weight, or from about 50% to about 60% by weight.

[0084] According to some embodiments, the precipitated carbonate

composition may have a median particle size (d 50 ) in the range from about 5 microns to about 15 microns. For example, the precipitated carbonate composition may have a median particle size in the range from about 5 microns to about 10 microns, or from about 7 microns to about 10 microns. According to some embodiments, the median particle size may also be described as a median crystal size of the precipitated carbonate composition.

[0065] According to some embodiments, the precipitated carbonate

composition may have a BET surface area greater than or equal to about 1 .7 m 2 /g, such as, for example, greater than or equal to about 1 .8 m 2 /g, greater than or equal to about 1 .9 m 2 /g, greater than or equal to about 2.0 m /g, greater than or equal to about 2.1 m 2 /g, greater than or equal to about 2.2 m 2 /g, greater than or equal to about 2.3 rrTVg, greater than or equal to about 2.4 m 2 /g, greater than or equal to about 2.5 m 2 /g, greater than or equal to about 2.8 m 2 /g, greater than or equal to about 2.7 m 2 /g, greater than or equal to about 3.0 m 2 /g, greater than or equal to about .0 m 2 /g, greater than or equal to about 5.0 m 2 /g, greater than or equal to about 8.0 m 2 /g, greater than or equal to about 7.0 m /g, greater than or equal to about 8.0 m 2 /g, greater than or equal to about 9.0 m /g, greater than or equal to about 10.0 m 2 /g. [0066] According to some embodiments, the precipitated carbonate composition may include greater than or equal to about 87% CaC0 3 , such as, for example, greater than or equal to about 90% CaC0 3 , greater than or equal to about 91 % CaC0 3) greater than or equal to about 92% CaC0 3 , greater than or equal to about 93% CaC0 3 , greater than or equal to about 94% CaC0 3l or greater than or equal to about 95% CaCOa.

[0067] According to some embodiments, a method for producing a recycled filler from carpet may include providing a feed stream that may include a carpet ash mud that may have greater than or equal to about 1 % of a feed hydroxide based on the total solids content. The method may also include adding water to the feed stream to form a diluted stream. The method may also include carbonating the diluted stream mud to form a recovered carbonate composition. According to some embodiments, the hydroxide may include Ca(OH} 2 , and the carbonate may include CaC0 3 .

[0068] According to some embodiments, the carpet ash mud may include the feed hydroxide and an oxide. According to some embodiments, the carpet ash mud may include greater than 86.5% of the feed hydroxide, a feed oxide, or a combination thereof, based on the total solids content. For example, the carpet ash mud may include greater than or equal to about 88%, greater than or equal to about 90%, greater than or equal to about 92%, greater than or equal to about 93%, greater than or equal to about 94%, greater than or equal to about 95%, or greater than or equal to about 96% of the feed hydroxide, a feed oxide, or a combination thereof, based on the solids content. According to some embodiments, the feed hydroxide and the feed oxide may be a mineral hydroxide and a mineral oxide with the same positively charged component. For example, the hydroxide may be Ca{OH) 2 and the oxide may be (CaO).

[0089] According to some embodiments, the diluted stream may have a solids content less than 15% by weight based on the total weight of the diluted stream, such as, for example, less than or equal to about 14% by weight, less than or equal to about 12% by weight, less than or equal to about 11 % by weight, less than or equal to about 10% by weight, or less than or equal to about 8% by weight based on the total weight of the diluted stream.

[0070] According to some embodiments, the diluted stream may have a solids content greater than 35% by weight based on the total weight of the diluted stream, such as, for example, greater than or equal to about 37% by weight, greater than or equal to about 40% by weight, greater than or equal to about 43% by weight, greater than or equal to about 45% by weight, or greater than or equal to about 50% by weight based on the total weight of the diluted stream.

[0071] According to some embodiments, the method may include quenching a carpet ash with water vapor to form the feed stream. According to some embodiments, quenching the carpet ash may include adding steam to the carpet ash to form the feed stream. According to some embodiments, the carpet ash may have been formed from incinerated waste carpet, post-consumer carpet, or carpet backing.

[0072] According to some embodiments, water may be added to the carpet ash in a sufficient amount to form calcium hydroxide (Ca(OH) 2 ) from calcium oxide (CaO). According to some embodiments, calcium hydroxide may be formed from the calcium oxide by dry slaking. According to some embodiments, the amount of water may be sufficient to form greater than 0% calcium hydroxide, greater than or equal to about 10% calcium hydroxide, greater than or equal to about 20% calcium hydroxide, greater than or equal to about 30% calcium hydroxide, greater than or equal to about 40% calcium hydroxide, greater than or equal to about 50% calcium hydroxide, greater than or equal to about 60% calcium hydroxide, greater than or equal to about 70% calcium hydroxide, greater than or equal to about 75% calcium hydroxide, greater than or equal to about 80% calcium hydroxide, greater than or equal to about 85% calcium hydroxide, greater than or equal to about 90% calcium hydroxide, greater than or equal to about 95% calcium hydroxide, greater than or equal to about 97% calcium hydroxide, greater than or equal to about 98% calcium hydroxide, or greater than or equal to about 99% calcium hydroxide. According to some embodiments, the amount of water may be sufficient to form about 100% calcium hydroxide, or to convert substantially all of the calcium oxide to calcium hydroxide, According to some embodiments, the calcium hydroxide may be formed as a powder or particulate form of calcium hydroxide.

According to some embodiments, water may be added by adding steam to the carpet ash to form the calcium hydroxide. According to some embodiments water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, to form at least part of the carpet ash mud. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, for example, prior to carbonating. According to some embodiments, carpet ash (for example, from a boiler or incinerator) may be combined with steam in a sufficient amount to convert about 100% of the calcium oxide to calcium hydroxide, such that the calcium hydroxide remains in a powder or particulate form, and the powder or particulate calcium hydroxide may then be combined with water.

[0073] According to some embodiments, the feed hydroxide may include a mineral hydroxide, such as, for example, an alkali earth metal hydroxide. The feed hydroxide may include Ca(OH) 2 . The recovered carbonate composition may include a mineral carbonate, such as, for example, an alkali earth metal carbonate. The recovered carbonate composition may include calcium carbonate (CaC0 3 ) or magnesium carbonate (MgCOs).

[0074] The feed stream may have a solids content in a range from about 35% to about 90% by weight based on the total weight of the feed stream, such as, for example, in a range from about 40% to about 80% by weight, or in a range from about 60% to about 75% by weight based on the total weight of the feed stream,

[0075] According to some embodiments, the feed stream may include greater than or equal to about 5% of the feed hydroxide based on the total solids content, such as, for example, greater than or equal to about 10% of the feed hydroxide, greater than or equal to about 15% of the feed hydroxide, or greater than or equal to about 20% of the feed hydroxide based on the total solids content. For instance, the carpet ash mud may include the feed hydroxide in a range from about 20% to about 88.5% based on the total solids content, such as, for example, in a range from about 50% to about 85%, from about 50% to about 75% based on the total solids content. According to some embodiments, the feed stream may include the feed hydroxide in a range from about 1 % to about 20% based on the total solids content, such as, for example, in a range from about 1 % to about 10%, from about 5% to about 15%, from about 10% to about 15%, from about 5% to about 10%, from about 1 % to about 5% based on the total solids content.

[0076] According to some embodiments, the feed stream may include an oxide. According to some embodiments, the oxide may include a mineral oxide, such as, for example, an alkali earth metal oxide. The oxide may include at least one of calcium oxide (CaO), magnesium oxide (MgO), silica (Si0 2 ), alumina {AI2O3), phosphorous pentoxide (PaOs), iron oxide (e.g., Fe 2 0 3 ), or sulfur as S0 3 . According to some embodiments, the feed stream may include greater than or equal to about 10% of the oxide based on the total solids content, such as, for example, greater than or equal to about 15%, greater than or equal to about 20%, greater than or equal to about 25%, or greater than or equal to about 30% of the oxide based on the total solids content. According to some embodiments, the feed stream may include the oxide in a range from about 1 % to about 30% based on the total solids content, such as, for example, from about 1 % to about 25%, from about 1 % to about 20%, from about 1 % to about 15%, from about 5% to about 25%, from about 10% to about 25%, from about 15% to about 25%, from about 15% to about 25%, from about 5% to about 20%, or from about 10% to about 20% based on the total solids content.

[0077] According to some embodiments, the method may include adding a second hydroxide prior to the carbonating step. The second hydroxide may be added to the feed stream. The second hydroxide may be added to a diluted stream. Adding the second hydroxide may include adding a slurry containing the second hydroxide.

[0078] According to some embodiments, adding the second hydroxide to may facilitate precipitation of a precipitated carbonate composition. The precipitated carbonate composition may be different from the recovered carbonate composition. According to some embodiments, the precipitated carbonate composition may have a carbonate component and a second component.

[0079] According to some embodiments, the second hydroxide may form a carbonate. For example, the carbonate may be precipitated onto at least a portion of the surface of a component of the carpet ash mud. According to some embodiments, the precipitated second hydroxide and the component may form the precipitated carbonate composition.

[0080] According to some embodiments, a method for facilitating precipitation of a carbonate composition may include adding a hydroxide to a carpet ash mud. The method may also include carbonating the carpet ash mud and the hydroxide to produce a precipitated carbonate composition.

[0081] According to some embodiments, the adding the hydroxide may inciude adding a slurry containing the hydroxide to the carpet ash mud. According to some embodiments, the carpet ash mud may be diluted, for example, with water, prior to adding the hydroxide or the slurry of the hydroxide.

[0082] According to some embodiments, the method may include adding water to the carpet ash mud prior to the carbonating step. The water may react with an oxide of the carpet ash mud to form an inorganic hydroxide similar to the added hydroxide. For example, according to some embodiments, Ca(OH) 2 may be added to the carpet ash mud, and CaO in the carpet ash mud may react with the added water to form Ca(OH) 2 . According to some embodiments, adding the water to the carpet ash mud may inciude adding steam to the carpet ash mud. [0083] According to some embodiments, the precipitated carbonate composition may include a carbonate component that may coat, encapsulate, react with, or bond, either physically or chemically, with at least a portion of the surface of a component of the carpet ash mud. For example, the carbonate component may adsorb to at least a portion of the surface of the component. According to some embodiments, the carbonate component may physically react with or attach to at least a portion of the component, such as, for example, through physisorption. According to some

embodiments, the carbonate component may chemically bond with the surface of the component, such as, for example, through ionic or van der Waals bonds. According to some embodiments, the carbonate component may coat or encapsulate substantially all of the surface of the component, such as, for example, by forming a carbonate layer over at least part of, a majority of, or substantially all of the surface area of the component.

[0084] According to some embodiments, the precipitated carbonate

composition may include a multi-component composition. The precipitated carbonate composition may include a carbonate component and a second component different from the carbonate component.

[0085] According to some embodiments, the carbonate component may include, for example, CaC0 3 or MgC0 3 . According to some embodiments, the carbonate component may include a carbonate phase. The carbonate phase may include a calcium carbonate phase, such as, for example, a calcife phase, an aragonite phase, or a combination thereof. The carbonate phase may, according to some embodiments, include a magnesium carbonate phase, such as, for example, a triclinic phase,

[0086] According to some embodiments, the second component may include a phase different from the carbonate component. For example, the second component may include a non-carbonate component, such as, for example, an oxide. The oxide, may include, for example, calcium oxide (CaO), magnesium oxide (MgO), silica (Si02), alumina (A! 2 03), phosphorous pentoxide (P2O5), iron oxide (e.g., Fe 2 O 3 ), sulfur as SO3, or any combination thereof. According to some embodiments, the second component may include a second carbonate component. For example, when the carbonate component is CaC0 3 , the second component may include MgC0 3 . According to some embodiments, the second component may include a different phase from the carbonate component. For example, the carbonate component may include a calcite phase, and the second component may include a triclinic phase, a cristobalite phase, or an amorphous phase (e.g., amorphous silica).

[0087] According to some embodiments, the precipitated carbonate

composition may include a carbonate component bound to at least a portion of a surface of a second component of the precipitated carbonate composition. For example, the carbonate component may be chemically bound to the second

component, such as, for example, through ionic, coordinate covalent (dative), or van der Waals bonds. According to some embodiments, the carbonate component may physically bond or attach to the second component. According to some embodiments, the carbonate component may be adsorbed or physisorbed to the second component. According to some embodiments, the carbonate component may form a carbonate layer over the second component during the carbonating step. For example, the carbonate component may form a carbonate layer, shell, or coating that covers at least a portion of, a majority of, or substantially all of the second component. According to some embodiments, the carbonate component may coat, enclose, or encapsulate

substantially all of the second component. According to some embodiments, the second component may include a component of a carpet ash or carpet ash mud.

[0088] According to some embodiments, the precipitated carbonate

composition may include a carbonate component, a second component, and/or an interfacial component. The interfacial component may be, for example, a boundary region between the carbonate component and the second component. The interfacial component may include a chemical composition containing elements of the carbonate component and the second component. For example, when the precipitated carbonate composition includes a calcium carbonate as the carbonate component and a magnesium carbonate as the second component, an interfacial region may include calcium and/or magnesium diffusing into the other component, or a region containing a mixture of calcium carbonate and magnesium carbonate. An interfacial region may occur, for example, upon thermal treatment (e.g., sintering) of the precipitated carbonate composition.

[0089] According to some embodiments, adding the hydroxide may facilitate additional precipitation (e.g., improved yield) of the precipitated carbonate composition. For example, the hydroxide may form a carbonate that treats at least a portion of the surface of the component of the carpet ash mud, such as, for example, an oxide in carpet ash mud. During the carbonating, the hydroxide may react with, for example, carbon dioxide to form a carbonate that precipitates from a solution. The precipitate may include both the carbonate and the component from the carpet ash mud. By way of example, if the carbonate treats a magnesium oxide, the precipitated carbonate composition may include both a calcium carbonate component and a magnesium oxide component.

[0090] According to some embodiments, carpet ash mud may be formed by quenching a carpet ash with water vapor to form the carpet ash mud. According to some embodiments, quenching the carpet ash may include adding steam to the carpet ash to form the carpet ash mud. The carpet ash may have been formed from

incinerated waste carpet, post-consumer carpet, or carpet backing.

[0091] According to some embodiments, water may be added to the carpet ash in a sufficient amount to form calcium hydroxide (Ca(OH) 2 ) from calcium oxide (CaO). According to some embodiments, calcium hydroxide may be formed from the calcium oxide by dry slaking. According to some embodiments, the amount of water may be sufficient to form greater than 0% calcium hydroxide, greater than or equal to about 10% calcium hydroxide, greater than or equal to about 20% calcium hydroxide, greater than or equal to about 30% calcium hydroxide, greater than or equal to about 40% calcium hydroxide, greater than or equal to about 50% calcium hydroxide, greater than or equal to about 80% calcium hydroxide, greater than or equal to about 70% calcium hydroxide, greater than or equal to about 75% calcium hydroxide, greater than or equal to about 80% calcium hydroxide, greater than or equal to about 85% calcium hydroxide, greater than or equal to about 90% calcium hydroxide, greater than or equal to about 95% calcium hydroxide, greater than or equal to about 97% calcium hydroxide, greater than or equal to about 98% calcium hydroxide, or greater than or equal to about 99% calcium hydroxide. According to some embodiments, the amount of water may be sufficient to form about 100% calcium hydroxide, or to convert substantially all of the calcium oxide to calcium hydroxide. According to some embodiments, the calcium hydroxide may be formed as a powder or particulate form of calcium hydroxide.

According to some embodiments, water may be added by adding steam to the carpet ash to form the calcium hydroxide. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, to form at least part of the carpet ash mud. According to some embodiments, water may be added to the powder or particulate calcium hydroxide, or to a composition containing the powder or particulate calcium hydroxide, for example, prior to carbonating. According to some embodiments, carpet ash (for example, from a boiler or incinerator) may be combined with steam in a sufficient amount to convert about 100% of the calcium oxide to calcium hydroxide, such that the calcium hydroxide remains in a powder or particulate form, and the powder or particulate calcium hydroxide may then be combined with water.

[0092] According to some embodiments, the carpet ash mud may have a solids content in a range from about 35% to about 90% by weight based on the total weight of the carpet ash mud, such as, for example, in a range from about 40% to about 80% by weight, or in a range from about 60% to about 75% by weight based on the total weight of the carpet ash mud.

[0093] According to some embodiments, the carpet ash mud may include greater than or equal to about 1 % of a feed hydroxide based on the total solids content, such as, for example, greater than or equal to about 5% of the feed hydroxide, greater than or equal to about 10% of the feed hydroxide, greater than or equal to about 15% of the feed hydroxide, or greater than or equal to about 20% of the feed hydroxide based on the total solids content. For instance, the carpet ash mud may include the feed hydroxide in a range from about 20% to about 86.5% based on the total solids content, such as, for example, in a range from about 50% to about 85%, from about 50% to about 75% based on the total solids content. According to some embodiments, the carpet ash mud may include a feed hydroxide in a range from about 1 % to about 20% based on the total solids content, such as, for example, in a range from about 1 % to about 10%, from about 5% to about 15%, from about 10% to about 15%, from about 5% to about 10%, from about 1 % to about 5% based on the total solids content.

[0094] According to some embodiments, the carpet ash mud may include an oxide. For example, the oxide may be a component of the carpet ash. According to some embodiments, the oxide may include a mineral oxide, such as, for example, an alkali earth metal oxide. The oxide may include calcium oxide (CaO), magnesium oxide { gO), phosphorous pentoxide (P 2 0 5 ), iron oxide (e.g., Fe 2 0 3 ), or sulfur as SO3.

According to some embodiments, the carpet ash mud may include greater than or equal to about 5% of the oxide based on the total solids content, such as, for example, greater than or equal to about 10%, greater than or equal to about 15%, greater than or equal to about 20%, greater than or equal to about 25%, greater than or equal to about 30%, greater than or equal to about 40%, greater than or equal to about 50%, greater than or equal to about 60%, greater than or equal to about 70%, greater than or equal to about 80%, or greater than or equal to about 90% of the oxide based on the total solids content. According to some embodiments, the carpet ash mud may include an oxide in a range from about 1 % to about 90% based on the total solids content, such as, for example, in a range from about 1 % to about 80% based on the total solids content, such as, for example, in a range from about 10% to about 50%, from about 20% to about 80%, from about 30% to about 60%, from about 20% to about 40%, from about 1 % to about 30%, from about 1 % to about 10%, from about 40% to about 60%, from about 60% to about 80%, or from about 70% to about 90% based on the total solids content.

[0095] According to some embodiments, the precipitated carbonate

composition may include a low-brightness carbonate. The low-brightness carbonate may have a brightness less than or equal to about 65, such as, for example, less than or equal to about 60, less than or equal to about 50, less than or equal to about 40, less than or equal to about 30, less than or equal to about 25, less than or equal to about 20, less than or equal to about 19, less than or equal to about 18, less than or equal to about 17, or less than or equal to about 18, less than or equal to about 15, or less than or equal to about 14.

[0098] According to some embodiments, the precipitated carbonate

composition may be a recovered precipitated carbonate. According to some

embodiments, the recovered precipitated carbonate may be recovered from recycled carpet, such as, for example, from carpet ash or carpet ash mud.

[0097] According to some embodiments, the precipitated carbonate

composition may be a precipitated calcium carbonate (PCC), The PCC may include inorganic impurities including at least one of magnesium, aluminum, and silicon. [0098] According to some embodiments, the precipitated carbonate composition may have a median particle size in the range from about 5 microns to about 15 microns. For example, the precipitated carbonate composition may have a median particle size in the range from about 5 microns to about 10 microns, or from about 7 microns to about 10 microns.

[0099] According to some embodiments, the precipitated carbonate

composition may have a BET surface area greater than or equal to about 1.7 m 2 /g, such as, for example, greater than or equal to about 1.8 m 2 /g, greater than or equal to about 1.9 m 2 /g, greater than or equal to about 2.0 m 2 /g, greater than or equal to about 2.1 m 2 /g, greater than or equal to about 2.2 m 2 /g, greater than or equal to about 2.3 m 2 /g, greater than or equal to about 2.4 rn 2 /g, greater than or equal to about 2.5 m 2 /g, greater than or equal to about 2.6 m 2 /g, greater than or equal to about 2.7 m /g, greater than or equal to about 3.0 m 2 /g, greater than or equal to about 4.0 m /g, greater than or equal to about 5.0 m /g, greater than or equal to about 8.0 m 2 /g, greater than or equal to about 7.0 m 2 /g, greater than or equal to about 8.0 nf g, greater than or equal to about 9.0 m /g, greater than or equal to about 10.0 m 2 /g.

[0100] According to some embodiments, the precipitated carbonate

composition may include greater than or equal to about 87% CaC0 3 , such as, for example, greater than or equal to about 90% CaC0 3 , greater than or equal to about 91 % CaC0 3 , greater than or equal to about 92% CaC0 3 , greater than or equal to about 93% CaC0 3 , greater than or equal to about 94% CaC0 3 , or greater than or equal to about 95% CaC0 3 . [0101] According to some embodiments, the precipitated carbonate composition may have a loss on ignition (LOI) of greater than or equal to 40% by weight, such as, for example, greater than or equal to 50% by weight, or greater than or equal to 55% by weight. According to some embodiments, the precipitated carbonate composition may have a LOI in a range from about 40% to about 60% by weight, such as, for example, from about 40% to about 50% by weight, from about 45% to about 55% by weight, or from about 50% to about 60% by weight.

[0102] Although the examples and descriptions below may be discussed in terms of a calcium-based materials, such as CaO. Ca(OH)2, and CaC0 3 , if is

understood that the exemplary process could be carried out on other applicable oxides, hydroxides, or carbonates, such as, for example, mineral oxides, hydroxides, or carbonates, or alkali earth metal oxides, hydroxides, or carbonates.

[0103] FIG. 1 shows an exemplary system 100 for precipitating a carbonate. To facilitate understanding, FIG. 1 is described in terms of processing of carpet ash and carpet ash mud, and includes a mud/ash source 102. Mud/ash source 102 may be, for example, the output of an incinerator in which scrap, waste, post-consumer, or excess carpet or carpet backing is incinerated. According to some embodiments, mud/ash source 102 may include, for example, an output from a carpet factory, or may be incorporated into a carpet factory. When mud/ash source 102 is a carpet ash source directly from an incinerator, carpet ash may be the primary component. According to some embodiments, mud/ash source 102 may add water to the carpet ash to produce a carpet ash mud. Adding water to the carpet ash mud may be carried out by quenching the carpet ash with water vapor. [0104] Carpet ash may include large quantities of CaO, which may result from the decomposition of CaC0 3 in carpet backing during incineration of the waste carpet. The carpet ash may also constitute the solids component of the carpet ash mud.

According to some embodiments, the carpet ash or solids component of carpet ash mud may include greater than 90% of calcium-containing components. The calcium- containing components may include, for example, CaO, or a mixture of CaO and

Ca(OH) 2 . CaO and Ca(OH) 2 may also be part of the calcium-containing components of carpet ash mud, and the Ca(OH) 2 may result, for example, either from the carpet ash itself or from a reaction between the CaO component and water in the mud.

[0105] According to some embodiments, the carpet ash mud may include, for example, from about 60% to about 75% by weight of carpet ash. An exemplary carpet ash or solids component of the carpet ash mud may include, for example, about 92% total of CaO and Ca(OH) 2 , as measured by x-ray fluorescence (XRF) of the carpet ash or dried solids component of the carpet ash mud. The remainder of the carpet ash may be referred to as impurities, and may include, for example, gO, SiO 2 , and AI 2 O 3 . An exemplary carpet ash may include, for example, about 3% MgO, about 4% SiO 2 , and about 1 % AI 2 O 3 .

[0106] As shown in FIG. 1 , the carpet ash mud from ash/mud source 102 may pass to a solids adjusting tank 104. Solids adjusting tank 104 may be used to add water to the carpet ash mud to form a diluted stream by adjusting the solids content until it is in a range from, for example, about 10% to about 22% by weight of the diluted stream. Introduction of the water may convert an oxide component of the carpet ash mud into hydroxide. For example, CaO in the carpet ash mud may be converted to Ca(OH) 2 by the following reaction:

CaO + H 2 0 → Ca(0H) 2 .

[0107] According to some embodiments, water may be added to the carpet ash in a sufficient amount to form calcium hydroxide (Ca(OH) 2 ) from calcium oxide (CaO). According to some embodiments, the water may be added in a sufficient amount to form calcium hydroxide as a powder or particulate form of calcium hydroxide. For example, calcium hydroxide may be formed from the caicium oxide by dry slaking. According to some embodiments, the water may be added by adding steam to the carpet ash to form the calcium hydroxide, According to some embodiments, the calcium hydroxide, or a composition containing the calcium hydroxide, may form the at least part of the carpet ash mud. According to some embodiments, carpet ash (for example, from ash/mud source 102) may be combined with steam in a sufficient amount to convert about 100% of the caicium oxide to calcium hydroxide, such that the calcium hydroxide remains in a powder or particulate form, such as, for example, by dry slaking. The powder or particulate calcium hydroxide may then be combined with water, such as, for example, prior to carbonating.

[0108] According to some embodiments, a surfactant may be added to the carpet ash mud, such as in solids adjusting tank 104. The surfactant may prevent foaming of the composition during processing. The surfactant may also act as a defoamer. Suitable surfactants may include, but are not limited to, hydrocarbon-based or hydrocarbon oil-based surfactants, ethylene oxide-based surfactants, propylene oxide-based surfactants, imidazole-based surfactants, imidazoline-based surfactants, amide-based surfactants, or imidazoline/amide-based surfactants.

[0109] The solids-adjusted mud may then be transferred to a reactor 108 as a diluted feed material, where the hydroxide component may be carbonated to form a carbonate material. The carbonation may occur by adding a COs-containing gas to the reactor, which reacts with the hydroxide to precipitate the carbonate material.

According to some embodiments, the C0 2 -containing gas may be segregated in a gas storage or gas quencher 108. Gas quencher 108 may contain a C0 2 -containing gas, such as, for example, air or an exhaust gas. In some embodiments, the exhaust gas may include a flue gas from a production facility, such as a carpet factory. The C0 2 may be captured or sequestered from sources, such as an exhaust or flue gas, to provide a relatively higher percentage of COz. The COa-containing gas may include, for example, greater than about 10% C0 2 , greater than about 15% C0 2 , greater than about 20% C0 2 , greater than about 25% C0 2> greater than about 30% C0 2 , or greater than about 40% C0 2 .

[01 10] According to some embodiments, the C0 2 -containing gas may optionally be compressed using a compressor 1 10 prior to entering reactor 106. The C0 2 ~confaining gas may be added to reactor 106, where it reacts with the components of the diluted or solids-adjusted carpet ash mud to form a carbonate. For example, the C0 2 may react with water in the diluted or solids-adjusted ash mud to form carbonic acid (H2CO3), which may react with the calcium ions of the Ca(OH) 2 to form CaC0 3 . According to some embodiments, the composition of the recovered solids may include greater than or equal to about 90% CaC0 3 , such as, for example, about 95% CaC0 3 . The remainder of the recovered solids may include MgO, Si0 2 , and Al 2 0 3 impurities, as well as unreacted CaO,

[01 11] According to some embodiments, the carbonating step may include over-carbonating the reaction, in which additional C0 2 may be added to reactor 108 in excess of the amount needed to convert substantially all of the Ca(OH) 2 into CaC0 3 .

[01 12] The CaC0 3 from the carbonation reaction may result in precipitated calcium carbonate (PCC). According to some embodiments, the PCC may have a median particle size in the range from about 5 microns to about 20 microns, such as, for example, from about 5 microns to about 15 microns, from about 5 microns to about 10 microns, or from about 7 microns to about 10 microns. The particle size of PCC produced by the exemplary recovery method described in this disclosure may be relatively larger than traditional PCC production methods.

[01 13] According to some embodiments, the PCC may have a BET surface area greater than or equal to about 1 ,5 m 2 /g, such as, for example, greater than or equal to about 1.7 m 2 /g, greater than or equal to about 2.0 m 2 /g, or greater than or equal to about 2.5 m /g. Relative to traditional PCC production methods, the method disclosed herein may produce particles having a relatively higher BET surface areas than traditional precipitation methods.

[01 14] According to some embodiments, the PCC produced may be a low- brightness carbonate. According to some embodiments, the low brightness carbonate may have a brightness less than or equal to about 40 or less than or equal to about 20.

[01 15] After carbonating in reactor 106, the recovered carbonate (e.g., PCC) may be transferred to a slurry holding tank 1 12. The recovered PCC may be optionally sent to a post-processing facility 1 14 to be dried, milled, fired, or screened according to methods generally known in the art. The recovered PCC may be used as a filler or pigment in various processes and manufacturing methods, such as in carpet backing, pigments, or fillers, such as fillers for polymers.

[01 18] According to some embodiments, during post-processing 1 14, the PCC may be treated (e.g., heat treated) to produce a high-brightness carbonate.

[01 17] The PCC, whether low-brightness PCC or high-brightness PCC, may be used for various applications, including as a filler for carpet backing, films, plastics, or agriculture. The low-brightness PCC may also provide certain advantages, for example, as a filler for carpet backing and may reduce the cost of the subsequent manufacture of the carpet backing.

[01 18] According to some embodiments, a step of adding a hydroxide may be included in the system 100. For example, a Ca(OH) 2 holding tank 1 16 may receive Ca(OH) 2 from a lime silo 1 18. Lime si!o 118 may, according to some embodiments, be replaced with an alternative source of Ca(OH) 2 . In some embodiments, Ca(OH} 2 from holding tank 1 18 is added to the reactor 106 prior to carbonation. The Ca(OH) 2 can be mixed with the diluted feed material from solids adjusting tank 104 to promote

interactions between the Ca(OH) 2 and the feed stock material. Without wishing to be bound by a particular theory, it is believed that adding Ca(OH) 2 may facilitate

precipitation of a carbonate that treats part of the surfaces of various impurities or components, such as, for example, unreacted CaO, of the carpet ash mud in reactor 106. For example, the Ca(OH) 2 may precipitate a carbonate to treat MgO, Si0 2 , A! 2 O 3 , SiO 2 , and CaO in reactor 106 with the newly-added Ca{OH) 2 from holding tank 1 16, The carbonate may physically or chemically attach to part or substantially all of the surface area of the components, such that it may coat part of the surfaces of the MgO, SI0 2 , Al 2 0 3 , Si0 2i and CaO during carbonation.

[01 19] Without wishing to be bound by a particular theory, the Ca(OH) 2 may form a carbonate layer over some or substantially all of a component of the carpet ash mud during the carbonation step.

[0120] According to some embodiments, the Ca(OH) 2 may be added in a range from about 1 % to about 10% by weight relative to the feed stock.

[0121 ] FIG. 2 shows exemplary steps for an exemplary carbonate recovery process 200. At step 202 carpet ash mud is received from a carpet ash mud source. Step 202 may, according to some embodiments, include the processes described for providing a carpet ash mud from mud/ash source 102 in FIG. 1 . At step 204, a solids control step may be performed by adding water to the carpet ash mud. The solids control step may be performed using a solids adjusting tank 104, as shown in FIG. 1 . An optional hydroxide adding step 206 may be performed after the solids control step 202, which may facilitate precipitation of the impurities and oxides as part of a PCC composition. An exemplary hydroxide adding step is described above with reference to FIG. 1 , including holding tank 1 16 and reactor 108. At step 208, carbonation is performed on a slurry containing a hydroxide through the addition of a C0 2 -containing gas. An exemplary carbonafing step is described with reference to FIG. 1 and reactor 108. The C0 2 may result from a C0 2 capture step 210, in which captured C0 2 is used to perform the carbonation. Exemplary CO2 capture is described in FIG. 1 , with reference to gas quencher 108. After carbonation, optional thermal treatment (e.g., firing or sintering), milling, grinding, screening, and/or other post-processing may be performed at step 212.

EXAMPLES

[0122] A control sample was prepared from carpet ash using a slaking process, which did not appear to initiate hydration of the ash. In the control sample, 700 grams of the ash were added to 7.0 liters of water at 17 °C for 30 minutes. The temperature was monitored and no temperature rise was observed, indicating that slaking of ash may be ineffective for producing Ca(OH) 2 from carpet ash, which may inhibit CaC0 3 formation.

[0123] Exemplary samples were also prepared to determine whether lime could be used to treat carpet ash mud particles to improve the efficiency of PCC formation. The samples were prepared by adding 1 ,235 grams of lime to 11.4 liters of water at 17 °C. 700 grams of carpet ash were mixed with 7.0 liters of water in a reactor vessel, with an initial temperature of 17 °C, for 30 minutes. No temperature rise was observed during mixing. Four liters of the lime slurry were then added to the carpet ash slurry, and the resulting mixture had an initial temperature of 27 °C.

[0124] The resulting ash-lime slurry was then carbonated by adding 2.5 liters of C0 2 and 8.1 liters of air. The carbonation was carried out in the reactor at 700 rpm. The reaction was monitored by observing the temperature rise of the slurry mixture until the maximum temperature was reached. Once the highest temperature value was reached (about 50.5 °C in this example), the reaction t was considered complete due to depletion of the Ca(OH) 2 , indicating the end of the reaction. [0125] The carbonated slurry mixture was then over-carbonated, by carbonating to create a saturated amount of carbonic Acid (H2CO3) in the slurry mix, for 20 minutes to ensure completion of the carbonation reaction.

[0126] After the over-carbonation, 1.5 liters of the end product were removed from the reactor for chemical composition analysis. The removed sample was designated sample A.

[0127] After removing sample A, 3 liters of the lime slurry were added to the reactor and a new reaction started, having an initial temperature of 45 0 C. This reaction was allowed to proceed until the conductivity of the solution reached a minimum. The conductivity was measured using a hand held Conductivity meter model (WVR 89094- 958), calibrated using standardized solutions of 5,000 and 10,000 microsiemens. After the lime slurry was added, the reaction was allowed to proceed to completion in which the temperature was about 53 °C. Once the reaction was completed, a 1.0 liter sample was extracted and designated sample B. This sample was also chemically analyzed.

[0128] Samples A and B were then chemically analyzed. The composition of samples A and B are shown below in Table 1.

TABLE 1

[0129] Samples A and B were also screened using a 325 mesh and the quantity of +45 micron residue was determined. The chemical composition of the residue was also determined.

[0130] As shown by these examples, including Table 1 , use of a carpet ash mud as an input to a carbonate recovery process (samples A and B) may be

advantageous over a slaking process (control). A hydroxide adding step, as used in Sample B, may also improve the output efficiency of the carbonate recovery. Without wishing to be bound by a particular theory, it is believed that adding the hydroxide, such as through the addition of Ca(OH) 2! allows impurities, such as unreacted CaO, Si0 2 . MgO, and Si0 2 to be carbonated, thereby producing additional CaC0 3 .

[0131] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims,