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Title:
PROCESS FOR RECOVERING METALS
Document Type and Number:
WIPO Patent Application WO/2017/075693
Kind Code:
A1
Abstract:
There is provided a process for treating a feed material comprising: contacting the feed material with a reducing agent within a contacting zone, wherein the feed material includes at least one operative metal-comprising compound, wherein each one of the at least one operative metal-comprising compound, independently, includes at least one operative metal species, wherein the operative metal of the operative metal species is one of nickel and iron, wherein the contacting is such that a reactive process is effected such that a solid intermediate product is produced, and such that a reaction mixture is disposed within the contacting zone and the reaction mixture includes the feed material, the reducing agent, and the solid intermediate product; wherein the reactive process is such that: for each one of the at least one operative metal-comprising compound, independently: for each one of the at least one operative metal species of the operative metal-comprising compound, independently, at least a fraction of the operative metal species of the operative metal- comprising compound is reduced such that the elemental form of the operative metal is produced; such that the solid intermediate product includes the produced elemental form of at least one of nickel and iron; quenching the reaction mixture; converting at least a fraction of the solid intermediate product to a gaseous intermediate product; and fractionating the gaseous intermediate product such that at least one operative metal-rich product is produced.

Inventors:
EMMANUEL NANTHAKUMAR VICTOR (CA)
KOVTUN SERGE (CA)
KHOZAN KAMRAN M (CA)
Application Number:
PCT/CA2016/000271
Publication Date:
May 11, 2017
Filing Date:
November 04, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
KHOZAN HOLDINGS INC (CA)
International Classes:
C22B5/16; C22B5/20
Domestic Patent References:
WO2013110183A12013-08-01
Foreign References:
GB856425A1960-12-14
US2757077A1956-07-31
Attorney, Agent or Firm:
SAJEWYCZ, Mark et al. (CA)
Download PDF:
Claims:
CLAIMS

1. A process for treating a feed material comprising: contacting the feed material with a reducing agent within a contacting zone, wherein the feed material includes at least one operative metal-comprising compound, wherein each one of the at least one operative metal-comprising compound, independently, includes at least one operative metal species, wherein the operative metal of the operative metal species is one of nickel and iron, wherein the contacting is such that a reactive process is effected such that a solid intermediate product is produced, and such that a reaction mixture is disposed within the contacting zone and the reaction mixture includes the feed material, the reducing agent, and the solid intermediate product; wherein the reactive process is such that: for each one of the at least one operative metal-comprising compound, independently: for each one of the at least one operative metal species of the operative metal- comprising compound, independently, at least a fraction of the operative metal species of the operative metal-comprising compound is reduced such that the elemental form of the operative metal is produced; such that the solid intermediate product includes the produced elemental form of at least one of nickel and iron; quenching the reaction mixture; converting at least a fraction of the solid intermediate product to a gaseous intermediate product; and fractionating the gaseous intermediate product such that at least one operative metal-rich product is produced.

2. The process as claimed in claim 1 ; wherein the contacting with the reducing agent effects reduction of iron of an iron oxide of the feed material.

3. The process as claimed in claim 1 or 2; wherein the contacting with the reducing agent effects reduction of nickel of a nickel oxide of the feed material.

4. The process as claimed in any one of claims 1 to 3; wherein the quenching includes water quenching.

5. The process as claimed in any one of claims 1 to 4; wherein the quenching is effected by contacting the reaction mixture with a liquid coolant.

6. The process as claimed in claim 5; wherein the liquid coolant includes water.

7. The process as claimed in any one of claims 1 to 6; wherein the converting at least a fraction of the solid intermediate product to a gaseous intermediate product includes contacting a treated feed material with a carbonylating agent such that at least one metal carbonyl is produced, wherein: each one of the at least one metal carbonyl, independently, includes at least one operative metal; and the treated feed material includes at least one of an elemental form of nickel and an elemental form of iron, wherein the at least one of an elemental form of nickel and an elemental form of iron is derived from the solid intermediate product.

8. The process as claimed in claim 7; wherein the carbonylating agent includes carbon monoxide.

9. The process as claimed in claim 7 or 8, further comprising: prior to the contacting of a treated feed material with a carbonylating agent, separating at least a fraction of gangue material from the solid intermediate product such that a gangue - depleted solid intermediate product, that is depleted in the gangue material, is produced, and such that the treated feed material includes the gangue-depleted solid intermediate product.

10. The process as claimed in claim 9; wherein the separation is based on differences in magnetic field.

1 1. The process as claimed in claim 10, further comprising: after the quenching, and prior to the magnetic separation, effecting size reduction of the solid intermediate product.

12. The process as claimed in claim 10 or 1 1, further comprising: after the magnetic separation, and prior to contacting of the treated feed material with the carbonylation agent, contacting the gangue-depleted solid intermediate product with a reducing agent.

13. A process for treating a solid material comprising: contacting a feed material with a reducing agent, wherein the feed material includes at least one operative metal-comprising compound, wherein each one of the at least one operative metal-comprising compound, independently, includes at least one operative metal species, wherein the operative metal of the operative metal species is one of nickel and iron, wherein the contacting is such that a reactive process is effected such that a solid intermediate product is produced; wherein the reactive process is such that: for each one of the at least one operative metal-comprising compound, independently: for each one of the at least one operative metal species of the operative metal- comprising compound, independently, at least a fraction of the operative metal species of the operative metal-comprising compound is reduced such that the elemental form of the operative metal is produced, such that the reactive process includes the reduction of the at least a fraction of the operative metal species of the operative metal-comprising compound; such that the solid intermediate product includes the produced elemental form of the operative metal; separating at least a fraction of gangue material from the solid intermediate product such that a gangue-depleted solid intermediate product, that is depleted in the gangue material, is produced; converting at least a fraction of the gangue-depleted solid intermediate product to a gaseous intermediate product; and fractionating the gaseous intermediate product such that at least one operative metal-rich product is produced.

14. The process as claimed in claim 13; wherein the contacting with the reducing agent effects reduction of iron of an iron oxide of the feed material.

15. The process as claimed in claim 13 or 14; wherein the contacting with the reducing agent effects reduction of nickel of a nickel oxide of the feed material.

16. The process as claimed in any one of claims 13 to 15; wherein the converting at least a fraction of the solid intermediate product to a gaseous intermediate product includes contacting a treated feed material with a carbonylating agent such that at least one metal carbonyl is produced, wherein: each one of the at least one metal carbonyl, independently, includes at least one operative metal; and the treated feed material includes at least one of an elemental form of nickel and an elemental form of iron, wherein the at least one of an elemental form of nickel and an elemental form of iron is derived from the solid intermediate product.

17. The process as claimed in claim 16; wherein the carbonylating agent includes carbon monoxide.

18. The process as claimed in claim 16 or 17, further comprising: prior to the contacting of a treated feed material with a carbonylating agent, separating at least a fraction of gangue material from the solid intermediate product such that a gangue- depleted solid intermediate product, that is depleted in the gangue material, is produced, and such that the treated feed material includes the gangue-depleted solid intermediate product.

19. The process as claimed in claim 18; wherein the separation is based on differences in magnetic field.

20. The process as claimed in claim 19, further comprising: prior to the magnetic separation, effecting size reduction of the solid intermediate product.

21. The process as claimed in claim 19 or 20, further comprising: prior to contacting of the treated feed material with the carbonylation agent, contacting the gangue-depleted solid intermediate product with a reducing agent.

22. The process as claimed in claim 1 1 or 20, wherein the effecting size reduction of the solid intermediate product includes wet grinding within a grinding zone.

23. The process as claimed in claim 21, wherein the material within the grinding zone, that is subjected to the wet grinding, includes from about 30 weight % solid material, based on the total weight of the material within the grinding zone, to about 60 weight % solid material, based on the total weight of the material within the grinding zone.

Description:
PROCESS FOR RECOVERING METALS

FIELD

[0001] The subject matter relates to processes for recovering metals from ores. BACKGROUND

[0002] High pressure acid leach processes, for recovering nickel and iron from various fractions (such as, for example, one or more of limonite, middlings, and saprolite) of laterite ore, have not been economical. Carbonylation could also be used for recovering nickel and iron from laterite ore, however, the presence of significant non-metallic fractions within the ore also render its direct processing to be uneconomical.

SUMMARY

[0003] In one aspect, there is provided a process for treating a feed material comprising contacting the feed material with a reducing agent within a contacting zone, wherein the feed material includes at least one operative metal-comprising compound, wherein each one of the at least one operative metal-comprising compound, independently, includes at least one operative metal species, wherein the operative metal of the operative metal species is one of nickel and iron, wherein the contacting is such that a reactive process is effected such that a solid intermediate product is produced, and such that a reaction mixture is disposed within the contacting zone and the reaction mixture includes the feed material, the reducing agent, and the solid intermediate product; wherein the reactive process is such that: for each one of the at least one operative metal-comprising compound, independently: for each one of the at least one operative metal species of the operative metal-comprising compound, independently, at least a fraction of the operative metal species of the operative metal- comprising compound is reduced such that the elemental form of the operative metal is produced; such that the solid intermediate product includes the produced elemental form of at least one of nickel and iron; quenching the reaction mixture; converting at least a fraction of the solid intermediate product to a gaseous intermediate product; and fractionating the gaseous intermediate product such that at least one operative metal-rich product is produced.

[0004] In another aspect, there is provided a process for treating a solid material comprising: contacting a feed material with a reducing agent, wherein the feed material includes at least one operative metal-comprising compound, wherein each one of the at least one operative metal-comprising compound, independently, includes at least one operative metal species, wherein the operative metal of the operative metal species is one of nickel and iron, wherein the contacting is such that a reactive process is effected such that a solid intermediate product is produced; wherein the reactive process is such that: for each one of the at least one operative metal-comprising compound, independently: for each one of the at least one operative metal species of the operative metal-comprising compound, independently, at least a fraction of the operative metal species of the operative metal- comprising compound is reduced such that the elemental form of the operative metal is produced, such that the reactive process includes the reduction of the at least a fraction of the operative metal species of the operative metal-comprising compound; such that the solid intermediate product includes the produced elemental form of the operative metal; separating at least a fraction of gangue material from the solid intermediate product such that a gangue-depleted solid intermediate product, that is depleted in the gangue material, is produced; converting at least a fraction of the gangue-depleted solid intermediate product to a gaseous intermediate product; and fractionating the gaseous intermediate product such that at least one operative metal-rich product is produced.

BRIEF DESCRIPTION OF DRAWINGS

[0005] The preferred embodiments of the process will now be described with reference to the following accompanying drawings, in which:

[0006] Figure 1 is a flowsheet illustrating an embodiment of the process. DETAILED DESCRIPTION

[0007] Referring to Figure 1 , a process is provided for treating a feed material is provided so as to facilitate separation of at least one operative metal from the feed material The operative metal is one of nickel and iron. In some embodiments, for example, the feed material is a solid feed material. In some embodiments, for example, the feed material is a solid feed material composition.

[0008] In some embodiments, for example, the feed material is derived from an ore, and in this respect, in some of these embodiments, for example, the feed material is a concentrate. In some embodiments, for example, the feed material is produced by effecting size reduction of a mined ore (for example, by crushing, milling and/or grinding). In some embodiments, for example, the mined ore is subjected to a drying step prior to the size reduction step.

[0009] In some embodiments, for example, the ore is laterite. In some embodiments, for example, the ore is limonite. In some embodiments, for example, the ore is saprolite.

[0010] In some embodiments, for example, the feed material is a solid particulate feed material composition, In some of these embodiments, for example, at least 90 weight % of the solid particulate feed material composition has a particle size of less than one (1) millimetre, measured using a Fisher Sub-Sieve Sizer (FSSS). Generally, in some embodiments, for example, the solid particulate feed material composition has a particle size of about 50 microns, measured using a Fisher Sub-Sieve Sizer (FSSS).

[0011] The feed material includes at least one operative metal-comprising compound. Each one of the at least one operative metal-comprising compound, independently, includes at least one operative metal species. In this respect, the feed material includes at least one operative metal species, wherein, for each one of the at least one operative metal species, independently, the operative metal is one of nickel and iron. In some embodiments, for example, the feed material includes one or more nickel oxides, one or more iron oxides, or both of one or more iron oxides and one or more nickel oxides. [0012] In step 10, the feed material is contacted with a reducing agent within a contacting zone to effect production of a solid intermediate product. In some embodiments, for example, suitable reducing agents include gaseous diatomic hydrogen, carbon monoxide and carbon. In some embodiments, for example, the contacting zone is disposed at a temperature of between 600 degrees Celsius and 1,200 degrees Celsius, and at a pressure of between one (1) and three (3) bars. In some of these embodiments, for example, the reducing agent contacting zone is disposed at a temperature of about 650 degrees Celsius and 750 degrees Celsius.

[0013] In some embodiments, the contacting zone is disposed within a reduction hearth furnace. In some embodiments, for example, the configuration of a reduction hearth furnace mitigates adhesion of material to its wall surface and also promotes more complete reduction.

[0014] In some embodiments, for example, the contacting with the reducing agent is such that a reactive process is effected such that the solid intermediate product is produced. The reactive process is such that, for each one of the at least one operative metal-comprising compound, independently, and for each one of the at least one operative metal species of the operative metal-comprising compound, independently, at least a fraction of the operative metal species of the operative metal-comprising compound is reduced such that the elemental form of the operative metal is produced. In this respect, the solid intermediate product includes the produced elemental form of at least one of nickel and iron. In some embodiments, the solid intermediate product includes the produced elemental form of nickel and iron. In some embodiments, the produced elemental form of nickel includes sponge ferronickel. Also, in this respect, a reaction mixture becomes disposed within the contacting zone and the reaction mixture includes unreacted feed material, unreacted reducing agent, and the solid intermediate product.

[0015] In some embodiments, the contacting with the reducing agent effects reduction of iron (i.e. an operative metal species) of an iron oxide (an operative metal-comprising compound) of the feed material. In some of these embodiments, the contacting with the reducing agent effects reduction of nickel (i.e. an operative metal species) of a nickel oxide (an operative metal-comprising compound) of the feed material.

[0016] The following are exemplary reactions which occur in the contacting zone, when the feed material composition is contacted with a reducing agent, and when the feed material is derived from laterite which has been dried and subjected to size reduction:

Fe 2 0 3 + 3 H 2 -» 2 Fe + 3 H 2 0

NiO + H 2 -» Ni + H 2 0

2Fe 2 0 3 + 6CO -> 4 Fe + 6 C0 2

N:0 + CO -> Ni + C0 2

C0 2 + C - 2 CO

[0017] In some embodiments, for example, the process further includes, in step 20, quenching the reaction mixture. In some of these embodiments, for example, the quenching is conducted at a cooling rate (sufficiently rapid) such that the quenched reaction mixture has a sufficiently porous surface. In some embodiments, for example, the quenching is such that a reduction in temperature of material at a surface of the reaction mixture of at least 200 degrees Celsius is effected within one minute. In some embodiments, for example, the reduction in temperature is at least 300 degrees Celsius within one minute. In some embodiments, for example, the reduction in temperature is at least 400 degrees Celsius within one minute.

[0018] In some embodiments, for example, the quenching is effected by contacting the reaction mixture with a coolant. In some embodiments, for example, the coolant is a liquid coolant. In some embodiments, for example, the liquid coolant includes water having a temperature of 20 degrees Celsius. In some embodiments, for example, the quenching includes water quenching. In some embodiments, for example, the coolant is a gaseous coolant having a temperature from about 25 degrees Celsius to about 100 degrees Celsius. [0019] In some embodiments, for example, the quenching is effected in a quenching zone that is separate from the reducing agent contacting zone. In this respect, the reaction mixture is conducted to a quenching zone, wherein the quenching is effected in the quenching zone.

[0020] In some embodiments, for example, the process further includes, prior to the contacting with the reducing agent, effecting a reactive process such that at least a fraction of a pre-feed material is converted to one or more nickel oxides, one or more iron oxides, or both of one or more nickel oxides and one or more iron oxides, such that a pre-treatment product is generated, wherein the feed material includes the pre-treatment product. In some embodiments, for example, the pre-feed material is derived from an ore and, in this respect, in some of these embodiments, for example, the pre-feed material is a concentrate. In some embodiments, for example, the pre-feed material is produced by effecting size reduction of a mined ore (for example, by grinding, crushing, milling and/or grinding). In some embodiments, for example, the mined ore is subjected to a drying step prior to the size reduction step. In some embodiments, for example, the reactive process is characterized as "breaking silicates". In some embodiments, for example, the reactive process is effected by contacting the pre-feed material with a reagent that includes an alkali earth metal- comprising compound, an alkaline earth metal-comprising compound or both of an alkali earth metal-comprising compound and an alkali earth metal-comprising compound. In some embodiments, for example, the reagent includes one or more halide-ion donating agents. Each one of the one or more halide ion-donating agents, independently, is an alkali earth metal-comprising compound or an alkaline earth metal-comprising compound. In some embodiments, for example, the contacting is effected within a contacting zone, wherein, within the contacting zone, the ratio of [moles of halide ion of the one or more halide ion- donating agents] to [moles of the at least one operative metal species] is between 0.5 and 15.

[0021] The process further includes, in step 50, contacting a treated feed material with a carbonylating agent to effect production of a gaseous intermediate product. [0022] The treated feed material includes at least one of an elemental form of nickel and an elemental form of iron, wherein the at least one of an elemental form of nickel and an elemental form of iron is derived from the solid intermediate product.

[0023] In some embodiments, for example, the treated feed material includes the solid intermediate product.

[0024] In some embodiments, for example, the carbonylating agent includes carbon monoxide.

[0025] In some embodiments, for example, the contacting is effected within a carbonylation zone. In some embodiments, for example, the carbonylation zone is disposed at a pressure of between 5 bar and 60 bar, and at a temperature of between 80 degrees Celsius and 120 degrees Celsius.

[0026] Exemplary reactions within the carbonylation zone include the following: Fe + 5 CO -» Fe(CO) 5 Ni + 4 CO - Ni(CO) 4

[0027] In some embodiments, for example, the contacting of the treated feed material with the carbonylating agent effects liberation of at least one metal carbonyl. Each one of the at least one metal carbonyl, independently, includes at least one operative metal (i.e. one of nickel and iron). In this respect, in some embodiments, for example, the gaseous intermediate product includes at least one metal carbonyl, and, also in this respect, includes any one of, or any combination of a nickel carbonyl and an iron carbonyl.

[0028] In some embodiments, for example, the solid intermediate product is treated in step 40 prior to the contacting with the carbonylation agent so as to effect depletion of gangue material, such as silicates. In this respect, in some embodiments, for example, the treated feed material, being contacted with the carbonylating agent, includes a gangue- depleted solid intermediate product. In some embodiments, for example, the treating step 40 includes separating at least a fraction of gangue material from the solid intermediate product based on differences in magnetic field such that the gangue-depleted solid intermediate product, that is depleted in the gangue material, is produced. In this respect, in some embodiments, for example, the separation can be described as a "magnetic separation". In some embodiments, for example, the separation includes low intensity magnetic separation. By separating the gangue material from the solid intermediate product, prior to the contacting of a treated feed material with the carbonylating agent, a reduced quantity of material is required to be further processed, and may increase yields of the elemental forms of one or both of nickel and iron.

[0029] In some embodiments, for example, after the quenching, such as when the quenching is effected by a liquid coolant, the solid intermediate product is produced in the form of lumps, and the lumps need to be broken down (size reduction) prior to the magnetic separation. In this respect, in some embodiments, for example, the process further includes, prior to the magnetic separation, effecting size reduction of the solid intermediate product, in step 30. In those embodiments where the process includes quenching of the reaction mixture, in some of these embodiments, for example, the size reduction is effected after the quenching. In some embodiments, for example, the size-reduction is effected by grinding. In some embodiments, the size-reduction is effected by wet grinding. In some embodiments, for example, the wet grinding is effected within a grinding zone, wherein the material within the grinding zone includes from about 30 weight % solid material, based on the total weight of the material within the grinding zone, to about 60 weight % solid material, based on the total weight of the material within the grinding zone. In wet grinding fewer airborne particulates, such as dust, are generated. Further, surface oxidation of the comminuted solid intermediate product is reduced. In some embodiments, the liquid coolant from quenching is used as the lubricant in the wet grinding. In some embodiments, for example, the size reduction is with effect that the solid particulate material becomes reduced in size such that, based on Particle Size Distribution analysis measured by Malvern Mastersizer Instrument, at least 99% of the particulate matter has a size of less than 150 microns. In some embodiments, for example, the average particle size of the particulate matter is from about 50 microns to about 100 microns, based on the Particle Size Distribution analysis measured by Malvern Mastersizer Instrument.

[0030] In some embodiments, for example, during the magnetic separation, at least some of the produced elemental form of at least one of the operative metals (nickel and iron) may become oxidized such that reduction of at least one operative metal species, now having an elevated oxidation state, is desirable so as to enable its recovery through the carbonylation step. In this respect, in some embodiments, for example, the process further includes, after the magnetic separation, and prior to contacting of the treated feed material with the carbonylation agent, contacting the gangue-depleted solid intermediate product with a reducing agent, in a similar manner to that described above with respect to the contacting of the feed material with the reducing agent such that a treated, gangue-depleted solid intermediate product is produced. In this respect, in some embodiments, for example, the treated feed material, being contacted with the carbonylating agent, includes a treated, gangue-depleted solid intermediate product.

[0031] The gaseous intermediate product, produced after the contacting of the treated feed material with the carbonylating agent, is subjected to fractional distillation so as to effect separation of an iron carbonyl-rich fraction and a nickel carbonyl-rich fraction from the gaseous intermediate product, such that the iron carbonyl-rich fraction and the nickel carbonyl-rich fraction become separated. In some embodiments, for example, each one of the iron carbonyl-rich fraction and the nickel carbonyl-rich fraction is supplied to a respective decomposition zone so as to effect its respective decomposition into a substantially pure form of the respective metal (ie. iron carbonyl of the iron carbonyl-rich fraction is decomposed within the decomposition zone so as to produce iron, and nickel carbonyl of the nickel carbonyl-rich fraction is decomposed within the decomposition zone so as to produce nickel). In some embodiments, for example, each of the decomposition zones is disposed at a temperature of between 220 degrees Celsius and 500 degrees Celsius, which is sufficient to effect the decompositions. Exemplary reactions within the decomposition zones include the following: Fe(CO) 5 -» Fe + 5 CO Ni(CO) 4 -» Ni + 4 CO

[0032] In some embodiments, for example the contacting of the treated feed material with the carbonylating agent also yields a solid residue that includes platinum group elements ("PGE"), and these can be separately recovered.

[0033] In the above description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the present disclosure. Although certain dimensions and materials are described for implementing the disclosed example embodiments, other suitable dimensions and/or materials may be used within the scope of this disclosure. All such modifications and variations, including all suitable current and future changes in technology, are believed to be within the sphere and scope of the present disclosure. All references mentioned are hereby incorporated by reference in their entirety.