| WO2021053669A1 | 2021-03-25 | |||
| WO2020035854A1 | 2020-02-20 |
| CN113104876A | 2021-07-13 |
| [000126] CLAIMS; 1. A process for the processing of solids wherein the solids are comprised of salts or oxides selected from metal oxides, metal hydroxides, metal carbonates, and the combination thereof, wherein the metal is a divalent cation, said process comprising the steps of: (a). Adding a salt of strong acid to a reaction mixture comprising OWB and OWB* strong acid; (b). Adding CO2 into said reaction mixture to produce a strong acid, in the form of OWB*strong acid and carbonate salt or a bicarbonate salt of a monovalent cation or a divalent cation, or the combination thereof, and precipitation of said carbonate salt; (c). Removing at least part the suspension comprising the carbonate salt and the solution comprising OWB* strong acid and separation between the carbonate salt and the solution to obtain a Resulting solution; (d). contacting at least part of the strong acid produced in (c) with solids comprising salts and/or oxides selected from metal oxides, metal hydroxides, metal carbonate or the combination thereof, wherein the metal is a divalent cation, and leaching at least part of said solids to produce a salt of strong acid that is added in step (a). 2. A process according to Claim 1 , wherein said reaction mixture comprises a solvent selected from water, at least one hydrophilic solvent and the combination thereof. 3. A process according to any one of Claims 1 or 2, wherein at least part of said hydrophilic solvent is separated from said Resulting solution before it is used in step (c). 4. A process according to any one of Claims 1 or 2, wherein at least part of said hydrophilic solvent remains in said resulting solution before it is used in step (c) 5. A process according to Claim 1 wherein the strong acid present in the Resulting solution, in step (d), is contacted with said solid, in the form selected from a free strong acid or OWB*strong acid or the combination thereof. 6. A process any one of Claims 1 -5, for use in processing solids comprising metal oxides or metal hydroxides or metal carbonate or salt of weak acid or the combination thereof, said process comprising the steps of: (e). Adding a salt of strong acid to a reaction mixture comprising OWB and OWB*strong acid, an hydrophilic solvent and water; (f). Adding CO2 into said reaction mixture to produce a strong acid, in the form of OWB*strong acid and precipitation of a carbonate salt of a divalent cation; (g). Removing at least part of the resulting suspension and separation of the carbonate or bicarbonate salt to get a resulting solution and the solid comprising of carbonate salt; and (h). Separation of at least part of the hydrophilic solvent from said Resulting solution and recycling the hydrophilic solvent to Step (a). (i). Separation of at least part of the strong acid from OWB*strong acid to get the free strong acid (j) Contacting said strong acid with a solid comprising of a metal oxide or a metal hydroxide or a metal carbonate or the combination thereof, wherein at least part of said solid reacts with the strong acid or the remaining OWB* strong acid or the combination thereof, to form a salt of strong acid and OWB. (k) Recycling the OWB and the salt of strong acid to step (a). A process as in Claim 6 wherein the solids of step (j) are contacted with water or an aqueous a salt of strong acid solution to get a Wash solution. A process as in Claim 6 wherein in Step (i) the strong acid is separated from the OWB* Strong acid by contacting it with an aqueous solution returning from Step (j) to get a resulting acidic solution. A process of any one of claims 6-8, wherein the resulting acidic solution is recycled to Step (j) to get a salt of Strong acid solution. A process as in claims 6 and 7 and 8 wherein part of the salt of Strong acid solution goes to Step (a). A process of any one of claims 6-8, wherein part of the salt of Strong acid solution goes to Step (i). A process of any one of claims 6-10, wherein the pH of the salt of Strong acid solution is in the range of pH 3 to 7. A process of any one of claims 1-11 wherein part of the Wash solution is added to the Strong acid solution. A process of any one of claims 6-12 wherein the pH of the salt of strong acid solution is at a pH of greater than 7. A process of any one of claims 1- 13 wherein the OWB comprises a tertiary amine A process of any one of claims Ito 13 wherein the OWB comprises a branched-chain tertiary amine including , among others, TEHA, tertiary amines wherein at least one of the chains is not branched, tertiary amines of pKl/2 higher than that of TEHA or the combination thereof. A process of any one of claims 1-6, for use in processing solids comprising metal oxides or metal hydroxides or metal carbonate, said process further comprising the steps of: (l). Contacting a solution comprising OWB*strong acid with a solid comprising of salts or oxides selected from metal oxides, metal hydroxides, metal carbonate, or the combination thereof, wherein the metal is in the form of divalent cation and wherein at least part of said solid reacts with the strong acid to form a Salt of strong acid. (m). Preparing a reaction mixture comprising of (1) at least one salt of a strong acid produced in step (a). (2). at least one organic weak base (OWB), (c) an hydrophilic solvent (m). Adding CO2 into said reaction mixture and producing OWB*strong acid and precipitation of a carbonate salt or a Suspension of the combination thereof. (o). Removing at least part of the suspension, comprising the OWB*strong acid and the carbonate salt and separation of the carbonate to get a Resulting solution and the solid comprising of carbonate salt. (p) Recycling the OWB* strong acid, hydrophilic solvent and the salt of strong acid to step (1). A process as in Claim 1 or Claim 17 wherein the reaction mixture comprises of at least one long chained alkanol or a long chain carboxylic acid, or the combination thereof A process as in Claims 1 to 18 wherein said solid is an ore or waste solids. A process as in Claims 1 to 18 wherein the solid is a Fly ash waste stream. A process as in Claim 19 wherein said fly ash is selected from fly ash obtained from municipal waste, fly ash obtained from sewage, fly ash obtained from power production units burning coal or liquid fuel or incinerated other types of organic waste streams or the combination thereof. A process according to Claims 1, 6, 19, 20 wherein said solid comprises cations selected from Calcium, magnesium, Zink, Manganese, Copper, other divalent cation and the combination thereof. A process according to Claims 1-22 wherein the solid is an ore comprising CaCO3 or CaMgCO3 or the combination thereof. A process as claimed in claim 1-22 wherein the alkyl tertiary amine comprises of at least one side chains selected of, methyl alkyl amine, ethyl alkyl amine, propyl alkyl amine, butyl alkyl amine, pentyl alkyl amine, or hexyl alkyl amine, (C7-Ci2)-alkyl amine or the combination thereof. A process as in Claim land 16 wherein the strong acid has a pKl/2 lower than 3. A process as in Claims 1 and 16, wherein the strong acid is selected from HC1, halogenic acids, H2SO4, HNO3 or the combination thereof. A process as in Claim 1-16 wherein the hydrophilic solvent is selected from an alkanol, alkanol ester, alkanol ether, polyols, polyol ether, polyol ester, hydrophilic polar solvents or the combination thereof. A process as in Claim 1-3 wherein the hydrophilic solvent is selected from ethanol, 1- propanol, iso-butanol or third butanol, esters, ethers, amides and polar solvents or the combination thereof. A process as claimed in claims 1-16 wherein the pKl/2 of the OWB is higher than 0 and lower than 7. A process as claimed in claims 1-16 wherein the reaction mixture comprises a hydrophobic diluent. A process as claimed in claims 1-16 wherein the solid is selected from ores comprising divalent carbonates having the formula M1(II)M2(II)(CO3)2, wherein Mi and M2 are divalent cations A process according to Claim 1-16 wherein the residual non-leached solid is leached in a second leaching step, with a strong acid solution. A process according to claim 1-16 wherein a Bleed stream is removed from the process in one or more points. A process as in Claim 22 wherein the pH of the Bleed stream is increased gradually by adding a base, selected from the Wash solution or CaCO3, and precipitates comprising divalent cation hydroxides or/and higher valent cations hydroxides fractions. A process as Claims 1 and 16 wherein the CO2 obtained by the reaction between the strong acid and the carbonates is collected, compressed and recycled to the process. A process as in Claims 1-16 wherein the solid is obtained from processing Cu-ore comprising Cu sulfides and Cu pyrites comprising also carbonates of divalent carbonate or divalent weak acid salts, A process according to step 1-16 wherein at least part of the solution in (d) is used for the production of Mg products. |
FIELD OF THE INVENTION
[0001] The present invention relates to a novel process for the beneficiation of ores of waste materials comprising of oxides or/and carbonates divalent cations materials, in particular, fly ash and ores. The invention reduces investment necessary and production costs associated with the process by reducing or abrogating the cost of removing the hydrophilic sol vent prior to the leaching step.
BACKGROUND OF THE INVENTION
[0002] Ores or waste streams comprised of oxide/carbonates of divalent cations contain, on the one hand, poisonous divalent cations and on the other hand, valuable raw materials. Some of the divalent cations, such as Manganese, Copper and/or Zinc tire products having a relatively high market value, while others, such as Calcium or Magnesium have a lower market but are still in high demand.
[0003] Processes were developed for processing salts of divalent cations and strong acids to convert them to MCO3, i.e, carbonate salts of the divalent cations. MCO3 may be used directly as a product or be converted to another type of divalent cation product, such as a pure oxide or hydroxide and soluble and insoluble salts of the cation or converting the cations into a metal.
[0004] The basic nature of the MO/ MCO 3 raw material MO/ M(0H) 2 , is of high importance in the methods that will be presented here and simplify the production processes and reduce the production costs.
[0005] In PCT Application Publication NumberWO 2020035854A1, it was demonstrated that a divalent salt of a strong acid can react with CO2 to produce the carbonate salt of the divalent cation, MCO3, using a formulation that comprises of OWB (Organic weak base), water and a hydrophilic solvent.
[0006] The salt of the strong acid reacts with CO2 water and OWB, as presented in Step 1: Step 1.
2* OWB + M(II)X 2 + H 2 O + CO 2 ===== 2*0WB*HX + M(II))C0 3 where the presence of a hydrophilic solvent is required for Step 1 to take place. [0007] In order to release the strong acid from the OWB, the hydrophilic solvent must be removed, as demonstrated in Steps 2 and Step 3 :
Step 2: Removal of the hydrophilic solvent
Step 3: OWB*Strong acid ===== OWB +HX (Acid release).
[0008] In the present invention, there is no requirement for the full removal of the hydrophilic acid prior to the acid release step, thus saving the costs of solvent removal in the process. As a result, there is a considerable simplification of the process and a significant reduction in the production costs.
[0009] It was found that there are several cases in which there is no need for the full cycle, in which a hydrophilic solvent is added in Step 1 in which MCO 3 is produced and removed before Step 3 in which the strong acid is removed from the OWB.
Several options are presented in the present invention:
1. Direct contact between the OWB* Strong acid phase (comprising also the hydrophilic solvent) and the solid to be leached. (See Fig 1.)
2. Back-Wash of the 0WB*HX with aqueous solution and using the resulting solution to leach the solids, and recycling the resulting solution, comprising M(II)X2 solution back to contact again the 0WB*HX phase (See Fig 2.)
3. Washing the solid to be leached with aqueous solution and using the resulting basic aqueous to react with the 0WB*HX and produce M(II)X2 solution along with HX that is released from the 0WB*HX. The acidic aqueous solution is again, used to leach the solids.
4. The combination of options 2 and 3.
[00011] Since the concentration of the strong acid in the aqueous solution is relatively low, due to the presence of the hydrophilic solvent, several recycling steps are needed in the options of Fig 1 and Fig 2 in order to obtain efficient leaching. In the following, there are presented methods to obtain such efficient leaching. Among the methods are included:
1. Using an OWB, which is stronger than TEHA, with a lower amount of hydrophilic solvent. By effecting this option, the reaction rate in Step 1 becomes drastically higher in comparison to methods employing an OWB such as TEHA 2. Partial wash of the hydrophilic solvent with MX2 aqueous solution. By effecting this option, acid release from the 0WBN*HX is increased, even while using a strong OWB.
3. Using a hydrophilic solvent that is hydrophilic enough to go from the OWB*HC1 phase to the M( II )X 2 aqueous solution, during the acid release step and/or the solid leaching step.
4. Returning the OWB*strong acid phase to the reaction step (Step 1) at Z higher than zero and optionally, in the case of Fly ash, contacting the OWB*strong acid/OWB with the basic solution obtained by contacting M(II)X2 solution with Fly ash/washed Fly ash.
[00010] With the above options and using the above methods, with or without a partial solvent back-wash, is sufficient to achieve efficient leaching without removing the hydrophilic solvent, in a separate step, prior to the leaching step.
[00011] The process in the instant invention now becomes:
Step 1. Solid (or Ore) + 0WB*HX == M(H)X 2 + OWB Leaching of solid/Ore
Step 2. M(II)X 2 + CO 2 + H 2 O + 2*0WB ===== 2*0WB*HX + M(II)C0 3
[00012] According to this aspect, in the above process, HX is a strong acid, OWB is a weak organic base, M(II)X2 is a salt of a divalent cation and a strong acid and the Ore/solid contains a divalent cation in the form of a MO and or M(0H)2 or MCO3.
[00013] According to this aspect, in the above process, the formulation in Step 1 may optionally include a hydrophilic solvent.
[00014] In the present invention, it was very surprisingly found that the OWB is a sufficiently strong base to extract a strong acid from its salt, in a single step, and in the leaching step, the strong acid present in the OWB*strong acid can be used efficiently for leaching of divalent cations from ores or waste streams. In this process the solids are MO or/and M(0H)2 or/and MCO3. This finding eliminates the need for fully removing of the hydrophilic solvent before the strong acid is reacted with the ore or back-washed from the 0WB*HX.
[00015] The present invention simplifies the process and reduces the production costs.
[00016] The present invention provides, in some aspects, a process whereby when a solid such as Fly ash is used, the volume of Fly-ash to be disposed of is reduced by a cycle in which M0/M(0H)2 product are leached from the fly ash to form MX2 and MX2 reacts with CO2 and water to form the carbonate salt MCO3 and OWB*strong acid, which will be used for leaching. OWB = Organic weak base. Wherein a weak base, as referred to herein, is a base having a pKl/2 that is less than 4
[00017] In the instant invention, pKl/2 = the pH in an aqueous phase that is in contact with an organic phase comprising OWB*HC1 and OWB at OWB*HC1 / (OWB + OWB*HC1) of 0.5 (meaning at Z value of 0.5).
[00018] The process provided herein can be used for the assimilation of CO2 in carbonate salts by splitting of strong acid salts into an acid and a carbonate salt.
[00019] There is an urgent need in many industries for the instant process and developing methods for same will lead to the reduction of the amount of waste produced.
[00020] In some aspects, the processes of this invention are very cost-effective, as compared to the current processes for the production of bases and acids.
[00021] PCT International Application Publication Number W02020035854A1 demonstrated that by using a formulation that is comprised of OWB, water and a hydrophilic solvent, a salt of strong acid can react with CO2 and OWB (organic weak base) as presented in eq. 1, to give a carbonate salt and OWB*strong acid. By removing the hydrophilic solvent, the basicity of the OWB is reduced and the free strong acid can be released at a reasonable concentration (a concentration that is economically feasible) for use in leaching and/or other applications.
[00022] Removing the hydrophilic solvent and releasing of the acid, however, increases both investment costs and the production costs.
[00023] In the present invention, a further improvement to the process provided in PCT International Application Publication Number W02020035854A1 is presented, which can be applied without the full or partial removal of the hydrophilic solvent and the strong acid from the formulation.
[00024] According to this aspect, the current method can be applied only in leaching of solids selected of solids comprised of oxides, hydroxides, carbonates, bicarbonates or salts of weak acids:
Eq. 1 2*0WB + M(II)X 2 +water + CO 2 ====== 2*0WB*HX + M-carbonate or
M-bicarbonate
[00025] Wherein: OWB is an organic weak base;
HX is a strong acid having at least one proton with pKl/2 lower than 2; and
MX is a divalent cation salt of strong acid.
Eq. 2 OWB *HX+ ore/waste solids ======== OWB +a divalent cation salt of a strong acid or a direct contact between 0WB*HX and the solids mentioned above;
[00026] Wherein the solids are selected from solids comprise of oxides, hydroxides, carbonates, bicarbonates or salts of weak acids.
[00027] The results obtained here and will be presented in the next pages, show, that the selectivity between the leaching of divalent cations to that of tri/higher valent cations, cations, in the case of in the case in which 0WB*HX is higher than that with the free acid HX.
[00028] For example, Aluminum or titanium oxide/hydroxide can be leached efficiently from fly ash by 2-4wt% HC1 solution, the same as Calcium oxide/hydroxide/carbonates. When the HC1 is present as OWB*HC1, or less concentrated HC1 solution, the leaching of Divalent / (tri valent or 4- valent) oxide or hydroxides, the selectivity becomes very high. The very high selectivity enables the leaching of CaC1 2 from Fly-ash, leaving behind the tri-four valent oxides/hydroxides, to get the CaC1 2 at much higher purity level. In another option, in which a basic CaX2 solution exiting the leaching step is contacted with CaX2 solution before going to the reaction step (where it reacts with CO2), and part of the multi-valent cations are precipitated. The same is said for using a carbonate ore to neutralize the CaX2/HX solution.
[00029] In the present invention there are several options for a process as the following:
Step 1: OWB + M(II)X2 + CO 2 + H2O ====== 0WB*HX + M(II)C0 3 optionally, in the presence of a hydrophilic acid.
[00030] In some aspects, the process obviates the need to remove the hydrophilic solvent from the 0WB*HX, and the strong acid is reacted with the waste stream/ ore to give a salt of a divalent cation and strong acid: Step 2: OWB*HC1 + waste stream/ore ======= OWB + M(II)X 2 +H2O.
[00031] Wherein the hydrophilic solvent if present in the reaction, goes with the M(II)X 2 solution and/or the OWB phase back to Step 1.
[00032] As referred to herein, the terms “weak organic base (OWB)” and “strong acid”, are defined as follows:
[00033] In some aspects, the term “OWB” may refer to a base of pKl/2 lower than 4.
[00034] In some aspects, the term "strong acid” may refer, in addition to classic strong acids known in the art, such as, HC1, H 2 SO4 or HNO3, the term is intended to encompass an acid having aa pKl/2 of from greater than 1, to a pKl/2 of less than 0.5In some aspects, reference to a strong acids may refer to one with a pK 1/2 of less than 4.
[00035] In some aspects of the invention, the processes provided may be applied in the recrystallization of carbonates of di-valent cations. According to this aspect, the reference to “divalent cation carbonates” will include salts of very low solubility, which are not readily recrystallized just by dissolution of the salts in water or solvent and crystallizing same. This invention, in some aspects, provides processes which are cost-effective means to recrystallize divalent cation carbonates.
[00036] In some embodied aspects of the invention, conventional processing of ores or solids producing a product stream and a waste stream comprising divalent cations, may then be subjected to the methods of this invention, whereby the various solids from the conventional processes, including those containing raw material ores or a solid waste stream or a product stream may be introduced and ultimately the divalent cation carbonates may be recrystallized from same, as herein described.
[00037] In some aspects, in part as exemplified herein, the processes of this invention lend themselves to application in broad processes currently in use in the chemical industry and/or biotechnology industry for the production of organic acids, solids obtained by incineration of organic materials and treatment of dilute CO 2 streams, and offer a green solution for same, as is urgently required inter alia, to address global warming, providing cost-effective unique solutions for same. SUMMARY OF THE INVENTION
[00038] This invention provides processes and applications relating to the finding that acid present in 0WB*HX and/or the acid released from 0WB*HX can efficiently leach solids comprising oxide/hydroxides and or carbonates of divalent cations.
[00039] It was surprisingly found that, the distribution coefficient of some hydrophilic solvents, if added in the process, between the 0WB*HX phase and the aqueous phase becomes lower, at lower Z values, of the 0WB*HX than at higher Z values.
[00040] As a result, the hydrophilic solvent goes from the OWB phase into the aqueous phase and further, as result, the strong acid can be much more effective in reacting with the solids and enables sufficient yields and leaching rate.
[00041] A strong acid bonded to an OWB can react directly with the various solids, without the need to release the strong acid, from 0WB*HX.
[00042] According to this aspect, the fact that the strong acid bonded to OWB can directly react with the desired solids eliminates the need for removal of a significant part of the hydrophilic solvent, providing for a much more cost-effective process for the production of carbonates from the salts of strong acids.
[00043] According to this aspect, such processes are feasible not only with a very weak OWB such as TEHA but also with OWB having much higher pKl/2 values.
[00044] As described further and exemplified herein, the use of OWB of a greater basicity than that of TEHA, enables the assimilation of CO2 at much lower CO2 pressure then required in PCT International Application Publication Number WO 2020/035854 Al and the release of the strong acid at lower production costs.
[00045] In some aspects of invention, various applications of this process adjustment are envisioned, as described allowing uniquely for more environmentally friendly processes, the ability to save raw materials (acid and bases) for applications in the fields of mining, Fly ash treatment, inorganic chemistry, biotechnology and other processes in industrial chemistry.
[00046] In some aspects of invention, various applications of this process adjustment may find application in combination with the use of recycled free strong acid in processes in which divalent cations are to be separated from solids comprising also tri and four valent cations. BRIEF DESCRIPTION OF THE DRAWINGS
[00047] Figure 1 schematically depicts an overview of embodied processes of this invention whereby direct contact between the OWB*Strong acid phase (comprising also the hydrophilic solvent) and the solid to be leached is accomplished. According to one embodiment as depicted in the figure, the solid (such as Fly ash or CaCOs containing ore) is contacted with OWB*Strong acid, in the presence of aqueous solution. The aqueous solution is derived from the water wash step. In the leaching step, the strong acid reacts with the solid to produce the salt of the strong acid solution. The waste solids after leaching must be washed efficiently to remove any traces of the OWB and dried. The wash solution is a solution of the hydrophilic solvent, salt of strong acid and water. This option may be done with or without the hydrophilic wash step.
[00048] Figure 2 schematically depicts an overview of the processes of this invention whereby leaching of Fly Ash or Carbonate is accomplished via acid-washed solution. According to one embodiment as depicted in the figure, a strong acid salt is moving between the Acid Back-wash unit and the Leaching unit. The pH in the Leaching unit varies from a more acidic pH, at the point of entering of salt of strong acid+acid solution derived from the Acid-Back-wash unit; to a more basic pH in the solution to the point in which the solution exits and goes to the Acid Back-wash. This change in pH assists both efficiency and selectivity in leaching and the acid back-wash.
DETAILED DESCRIPTION OF THE INVENTION
[00049] It has surprisingly been found that a strong acid can react with a solid:
• when a solid is directly contacted with an OWB*strong acid, or
• When the solid is contacted with a strong acid / strong acid aqueous solution that is recycled between an Acid Back-wash unit and a Leaching unit. [00050] In both options, the leaching can be obtained even by partial hydrophilic solvent removal or with no hydrophilic solvent removal. It was also found that the leaching can be efficient even with a OWB more basic than TEHA.
[00051] The use of OWB, which is more basic than TEHA, enables high selectivity between the leaching of cations with a faster reaction rate between the CO2, water, the salt of strong acid and the OWB.
[00052] In accordance with these two aspects of the invention, when solids comprising oxides/hydroxide and/or solids comprising carbonates, reacts with OWB*Strong acid, -even OWB that are more basic than TEHA can be used for leaching , indeed, this was the case, even when the acid concentration in the Leaching step is very low.
[00053] It was also found that using an OWB, such as an amine base, comprising a 2-ethyl- hexyl group and 1 -octyl group, (which is stronger base than TEHA) produces, in the reaction of Eq 1,, a reaction rate which is very high as compared to when same is carried out using TEHA.
[00054] In some aspects of the invention, this process step is particularly useful in providing a more cost-effective process.
[00055] In other embodiments, this invention provides a method for the leaching of solids comprised of carbonates and/or oxides / hydroxides of divalent cations, using an OWB which is as basic or more basic than TEHA, whereby the process includes only partial or no removal of a hydrophilic solvent. According to this aspect, and in some embodiments, an aqueous solution is present between the OWB*HC1 phase and the solid phase. This phase might move between the Back wash unit and the leaching unit or stay in the same unit that comprises both solid and liquid phases.
[00056] In some embodiment, this invention provides a process for the processing of solids wherein the solids comprising of salts or oxides selected from metal oxides or metal hydroxides or metal carbonate, or the combination thereof, wherein the metal is a divalent cation, comprising of:
(a). Adding a salt of strong acid to a reaction mixture comprising of OWB and OWB*strong acid (b). Adding CO2 into said reaction mixture to produce a strong acid, in the form of OWB*strong acid and carbonate salt or a bicarbonate salt of a monovalent cation or a divalent cation, or the combination thereof, and the precipitation of said carbonate salt
(c). Removing at least part the suspension comprising the carbonate salt and the solution comprising OWB*strong acid and separation between the carbonate salt and the solution to get the Resulting solution.
(d). contacting at least part of the strong acid produced in (c) with solids comprising salts and/or oxides selected from metal oxides, metal hydroxides, metal carbonate or the combination thereof wherein the metal is a divalent cation, and leaching at least part of said solids to produce salt of strong acid that is added in step (a).
[00057] In another embodiment said reaction mixture comprises a hydrophilic solvent selected from water, at least one hydrophilic solvent or the combination thereof.
[00058] In another embodiment, the hydrophilic solvent has a LogP (octanol/water) equal or lower than 0.35. In another embodiment the hydrophilic solvent has a LogP (octanol water) value of higher than -1. In another preferred embodiment, the hydrophilic solvent is selected from alkanol, alkanol ethers and di-alcohols.
[00059] In another embodiment the reaction mixture comprises an OWB, at least one hydrophilic solvent, water, a salt of strong acid and a hydrophilic strong acid.
[00060] In another embodiment, at least part of said hydrophilic solvent is separated from said Resulting solution before it is reacted with the solids. In another preferred embodiment at least part of the hydrophilic solvent is not separated from the solution before the contact between the solids and the strong acid.
[00061] In another embodiment, the strong acid is contacted with said solid, in the form of a free strong acid and in another preferred embodiment, the strong acid reacts with the solids in the form of OWB*strong acid. In a still further embodiment, the strong acid reacts in a mixture of free strong acid and OWB*strong acid.
[00062] In another embodiment, the solid is comprised of metal oxides or metal hydroxides or metal carbonate. In another process, a salt of strong acid is added to a reaction mixture comprising of OWB and OWB*strong acid, a hydrophilic solvent and water. According to this aspect, the CO2 is added and reacted to form OWB* Strong acid and a carbonate salt of a divalent salt.
[00063] In another embodiment, at least part of the resulting suspension is removed and the carbonate salt is separated to yield a resulting solution and the solid comprised of carbonate salt.
[00064] In another embodiment, at least part of the hydrophilic solvent is separated from said resulting solution and recycled to the reaction mixture. In that preferred embodiment, at least part of the strong acid is separated from OWB* strong acid to get the free strong acid. In that preferred embodiment said strong acid reacts with a solid comprised of a metal oxide or a metal hydroxide or a metal carbonate or the combination thereof, wherein at least part of said solid reacts with the strong acid or the remaining OWB* strong acid or the combination thereof, to form a salt of strong acid and OWB. According to this aspect, the OWB and the salt of a strong acid are recycled to the reaction mixture.
[00065] In some embodiments of this invention, the reaction between the strong acid and the solids may occur via a first option of direct contact between the solids and the OWB* Strong acid.
[00066] According to this aspect, and in one embodiment the strong acid is not washed from the resulting solution comprising the hydrophilic solvent, OWB and OWB* strong acid, and the salt of strong acid. Further according to this aspect, and in one embodiment, the resulting solution is used, as is, to leach the solids.
[00067] In another embodiment, the solids are wet with a solution of the salt of the strong acid. Further according to this aspect, and in one embodiment, the suspension comprising the remaining solids, that were not leached, are filtered and the liquids are used to form the reaction mixture.
[00068] According to this aspect, and in another embodiment, the remaining solids are washed to remove practically all of the OWB and the hydrophilic solvent.
[00069] Further according to this aspect, and in one embodiment, the OWB is a stronger base than TEHA. Further according to this aspect, and in one embodiment the hydrophilic solvent is a short alkanol. Further according to this aspect, and in one embodiment, the filtrate, comprising the OWB, hydrophilic solvent, a salt of strong acid and water are reacted with CO2 to form a suspension of M(II)C03 and OWB*Strong acid. [00070] In another embodiment at least a part of said suspension is removed and then separated to give a resulting solution and M(II)C03. In another embodiment the resulting solution reacts with said solids.
[00071] In another embodiment, the solids comprise a metal oxide M(II)O - or a metal hydroxide M(0H)2 or the combination thereof. In another embodiment the solids are Fly Ash.
[00072] In another embodiment, the solution comprising the salt of the strong acid exiting the leaching step is at a basic pH.
[00073] In another preferred embodiment the solution comprising the salt of strong acid exits the leaching step at a pH varying from 5 to 9, and in another preferred embodiment, the solution exits the leaching step at a pH lower than 5.
[00074] In another embodiment, the OWB is TEHA or a tertiary amine having pH 1/2 value similar to that of TEHA. In a more preferred embodiment, the OWB has a pKl/2 higher than that of TEHA, but lower than 5.
[00075] In another embodiment, OWB is a tertiary amine having two chains of 2-ethyl amine and one chain of octanol. In another preferred embodiment, the OWB is a tertiary amine stronger than TEHA but weaker than the amine comprising 2 chains of 2-ehtyl-hexyl and one chain of octanol.
[00076] In another embodiment, the concentration of the salt of strong acid is higher than 25wt%. In another embodiment, the CO2 pressure in the reactor step is higher than 4 atm.
[00077] In another embodiment, the remaining solids are washed with a hydrophilic solvent. In another embodiment, the resulting wash solution is mixed with an adsorbent that adsorbed the OWB. In another embodiment, the remaining solvent is recycled to the wash step of the solids. In another embodiment, the above wash procedure is used for washing of the M(II)C03 product.
[00078] This invention provides, in another embodiment, processes as described herein wherein the reaction between the strong acid and the solids may occur via a second reaction, whereby a reaction between the solids and the free strong acid that was backwashed from the OWB*strong phase is accomplished.
[00079] According to this aspect, and in one embodiment, at least part of the hydrophilic solvent is washed from the OWB* strong acid phase. [00080] According to this aspect, and in another embodiment, the remaining OWB*strong acid phase is washed with a solution comprising a salt of strong acid coming from the leaching step (see Figure 2).
[00081] According to this aspect, and in another embodiment, salt of strong acid that is enriched with strong acid is returned to the leaching step. According to this aspect, and in another embodiment, the recycling continue until the solids are efficiently washed for M(II) oxides or M(II) hydroxides or and M(II) carbonates. In another embodiment at least part of the salt of strong acid forms the reaction mixture to react with CO2 and water.
[00082] In another embodiment the salt of strong acid solution exits the leaching step at pH of greater than 3. In another preferred embodiment, the salt of strong acid solution exits the leaching unit at a pH of greater than 4 and less than 6 and in another embodiment at pH of higher than 6.
Washing of the wet solids
Since both the remaining solids, after leaching are wet with the hydrophilic solvent and might also be wet by the OWB, a process was developed in which a hydrophilic solvent is used to wash the solids (remaining solids or the product C a CO 3 ) and then the washing solution is applied to an adsorption column wherein the OWB is adsorbed and the solvent recycled to the wash step.
Purification of a from the reaction unit
[00083] As referred to herein the term “bleed” may refer, in some aspects, to a part of the aqueous solution that goes to the waste stream or to waste treatment in the processes/systems as described herein. Since various cations are leached along with the M(II) cation that creates the M(II)C03 product, a bleed is taken for purification.
[00084] In another embodiment, the pH of the bleed is increased by adding a carbonate salt. In another embodiment, the pH of the bleed is increased by adding a solution obtained from the water wash step, in the case that that solution is basic. In both cases, the precipitate might form as a single solid or in another preferred embodiment several precipitates are formed by gradually increasing the pH and filtering the more pure precipitates.
The OWB
[00085] In another embodiment, the OWB comprises a tertiary amine. In another embodiment, the OWB comprises a branched-chain tertiary amine including, among others, TEHA. In other embodiments, the OWB comprises a tertiary amine wherein at least one of the chains is not branched. In other embodiments, the OWB comprises a tertiary amine having a pKl/2 that is greater than that of TEHA. In some embodiments, the OWB may comprise a combination of any of the listed embodied options herein. In another embodiment, the OWB comprises a tertiary amine, wherein the pKl/2 of the amine is greater than 0 and less than 3.
Composition of the Solids:
[00086] In another embodiment, the solids are selected from ores or waste solids.
[00087] In another embodiment, the solids comprise Fly ash. In a further embodiment, the solids comprise sediment or are separated from municipal waste streams or industrial or agricultural waste streams.
[00088] In another embodiment, the solids are ores comprised of carbonate salts. In another embodiment, the carbonate salts comprise salts of divalent cations. In another embodiment, the solids are a mixed cations carbonate. In another embodiment, the solids are a waste stream of a Copper mining industry, in another preferred embodiment; the ore is comprised of other divalent cation carbonates or other anions such as silicates, sulfides, sulfates and other anions.
[00089] In another embodiment, the fly ash is selected from fly ash obtained from municipal waste, fly ash obtained from sewage, fly ash obtained from power production units burning coal or liquid fuel or incinerated other types of organic waste streams or the combination thereof.
[00090] In another embodiment, said solid comprises cations selected from Calcium, magnesium, Zink, Manganese, Copper, other divalent cations and the combination thereof. [00091] In another embodiment, the solid is an ore comprising C a CO 3 or CaMgCCh or the combination thereof.
The OWB
[00092] In another embodiment, the alkyl tertiary amine comprises of at least one side chain comprising a methyl alkyl amine, ethyl alkyl amine, propyl alkyl amine, butyl alkyl amine, pentyl alkyl amine, or hexyl alkyl amine, (C7 -Cl 2) -alkyl amine or the combination thereof.
The strong acid
[00093] In another embodiment, the strong acid has a pKl/2 of less than 3. In another embodiment, the strong acid is selected from HC1, halogenic acids, H2SO4, HNO3 or the combination thereof. In another embodiment, the salt of the strong acid is MgSO 4 .
The hydrophilic solvent and other solvents
[00094] In another embodiment, the hydrophilic solvent is selected from an alkanol, alkanol ester, alkanol ether, polyols, polyol ether, polyol ester, hydrophilic polar solvents or the combination thereof.
[00095] In another embodiment, the hydrophilic solvent comprises ethanol or 1 -propanol, or iso-butanol or third butanol, esters, ethers, amides and polar solvents or the combination thereof.
[00096] In another embodiment, the reaction mixture comprises a hydrophobic diluent.
Other processes to deal with various streams
[00097] In another embodiment, the residual non-leached solid is leached in a second leaching step, with a strong acid solution.
[00098] In another embodiment, a bleed stream is removed from the process in one or more steps in the process. [00099] In another embodiment, the pH of the Bleed stream is increased by adding a base, selected from; the Wash solution or C a CO 3 , In another embodiment the base is added gradually to obtain precipitates comprising divalent cation hydroxides or/and higher valent cations hydroxides fractions, according to their acidity, so that tri valent cations will precipitate first and the divalent cations afterwards.
[000100] In another embodiment, the CO2 obtained by the reaction between the strong acid and the carbonates is collected, compressed and recycled to the process.
EXAMPLES
Example 1: The kinetics of the production of CaCO 3 from CaC1 2 with the tertiaryamine (Octyl bis(2-ethylhexyl)) amine (OETA).
[000101] The pKl/2 of OETA is 1.5 (pH at the aqueous phase at Amine*HCl/total amine = 0.5)
[000102] Procedure: 7.33gr OETA*HC1, 5.75gr free OET, 5.07gr 1-propanol, 2.71gr CaC1 2 , 0.058gr CaCCh and 1.38gr H2O were added into a round bottom beaker. CO2 at 5bar pressure was added to the magnetic stirred beaker. Samples were taken for analysis at various time intervals. The samples were centrifuged and analyzed for acid concentration and determination of z value.
[000103] Results [000104] Conclusions: The reaction rate is very high compared to the reaction with TEHA (pKl/2 of 0.5) at the same reaction conditions.
Example 2: Leaching of Fly Ash with OETA*HC1
[000105] Fly ash material was washed 3 times with water before leaching (3.65g Fly Ash, 3.55g water,).
[000106] 0.56gr dry washed Fly ash, 5.43 gr OETA*HC1 ((Octyl bis(2-ethylhexyl)) amine) at Z=0.5, 1.41gr 1 -Propanol and 1.49 water were added into a stirred Erlenmeyer. The solution was stirred vigorously for 4 hours. The suspension was filtered to get solution and solids.
[000107] The solids were re -leached with 2wt% HC1 for 3 hours and filtered. The filtered solution was analyzed for Ca.
[000108] Results: Dissolved solids = 62.4 wt% of calcium and acid were analyzed. Final Z is 0.5
Titration of calcium in aqua phase after leaching and in leftover solids
Example 3 leaching of NOAH’s Fly Ash
[000109] Procedure: Fly ash obtained from NOAH’s company was washed 3 times using water (3.65gr Fly ash with 3 times water), filtered and dried. First leaching step) TEHA*HC1 at, z= 0.9 w, 1-propanol and water were added. (1-propanol: total amine = 40:60). The reaction was heated to 52 Celsius and left overnight.
Results
Example 4
[000110] TO A (Tri -octyl amine) as the Organic base ethanol as the solvent, P-CO2 = 2 bar.
[000111] Procedure: The procedure is similar to that in Experiment 3, using ethanol as the solvent. A single liquid phase was present and CaCOs crystals were formed.
[000112] Results: Z = 1
[000113] Step 2: Back extraction of HC1
[000114] 9gr of the upper phase was introduced into a vial. The solution was stripped at 60 degrees C, to remove practically all of the ethanol.
[000115] lOgr water is added into the vial and the solutions are stirred at RT for 30 minutes. Samples were taken from the aqueous phase and analyzed for acidity.
[000116] Result: The concentration of HC1 in the aqueous phase is 0.18wt%.
[000117] Conclusions:
[000118] The acid could not be back extracted to give reasonable concentration.
[000119] Example 5:
[000120] Step 1: The experiment is identical to Example 4 hereinabove but with TEHA as OWB, 1 -propanol as the solvent. The final Z value is about 1.0.
Step 2 Back-Extraction of HC1
[000121] 9gr of the upper phase obtained in the solution of Step 1 was introduced into a vial. The solution was stripped at 60 degrees C, to remove all of the solvent.
[000122] lOgr water is added into the vial and the solutions are stirred at room temperature for 30min. Samples were taken from the aqueous phase and analyzed for acidity.
[000123] Result: The concentration of HC1 in the aqueous phase is 1.8 wt%. [000124] Conclusions: The HC1 that was separated from CaC1 2 , using TEHA in a single phase, could be back-washed to give an aqueous solution of 1.8wt%.
[000125] It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples and that the present invention may be embodied in other specific forms without departing from the essential attributes thereof, and it is therefore desired that the present embodiments and examples be considered in all respects as illustrative and not restrictive, reference being made to the appended claims, rather than to the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein