Resin-in-leach process to recover nickel and/or cobalt in ore leaching pulps
A hydrometallurgical resin-in-leach (RIL) process for directly recovering nickel and/or cobalt. Simultaneous pulp leaching by adding an acid or base, dissolves the metals of interest with adsorption of the metals rendered soluble in on ionic exchange resin. Following elution of the changed resin, purification of nickel and cobalt present in the eluate can be recovered by conventional methods, such as precipitation, extraction by solvents and membranes. The regenerated resin is recirculated for further use.
1. A hydrometallurgical process for recovering Nickel and/or Cobalt in ore leaching pulps comprising:
a) a combined leaching and adsorption step, wherein an aqueous pulp comprising laterite, Nickeliferous oxide, or Cobaltiferous oxide ore, or a combination thereof containing a first metal selected from the group consisting of Nickel, Cobalt, and combinations thereof together with a second metal different from the first metal, and water, is concurrently leached and adsorbed, said leaching occurring by adding a mineral acid to dissolve the contained metals, and said adsorption immediately occurring by the presence of an ion exchange resin admixed with the pulp; and
b) at least one further step for metal elution under acidic conditions.
2. The hydrometallurgical process according to claim 1 comprising pH adjustment in at least one of step (a) or step (b) so as to best fit metal solubilization/precipitation performance while providing optimal and selective loading of Nickel and Cobalt into the resin.
3. The hydrometallurqical process accordingly to claim 1 comprising adjusting the pH of the process between about 0 and 5.
4. The hydrometallurgical process according to claim 3 comprising adjusting the pH of the process between about 1 and 3.
5. The hydrometallurgical process according to claim 1 wherein the leaching agent is selected from at least one of the group consisting of sulfuric acid, chloridric acid and nitric acid.
6. The hydrometallurgical process according to claim 1 comprising operating the process at atmospheric pressure and at a temperature below about 80.degree. C.
7. The hydrometallurgical process according to claim 1 comprising adding from at least one of the group consisting of iron, aluminum and metallic magnesium to the combined leaching and adsorption step, thereby eliminating impurities such as trivalent iron and copper.
8. The hydrometallurgical process according to claim 1 comprising adding a reducing agent to the combined leaching and adsorption step, thereby reducing and avoiding absorption of impurities.
9. The hydrometallurgical process according to claim 1 comprising adding at least one sulfide selected from at least one of the group consisting of H.sub.2S, NaHS and Na.sub.2S, thereby precipitating impurities.
10. The hydrometallurgical process according to claim 1 wherein said ion exchange resin is selected from the at least one of group consisting of picolylamine; bis(2picolyl) amine, n-methyl-2 picolylamine, n (2 hydroxyethyl) 2 picolylamine and n (2 hydroxypropyl) 2 picolylamine.
11. The hydrometallurgical process according to claim 1 wherein said metal elution occurs selectively and in multiple stages.
12. The hydrometallurgical process according to claim 1 wherein the elution of iron from the resin is performed by the addition of acidified water having a pH of about 2.
13. The hydrometallurgical process according to claim 1 wherein the elution of copper from the resin is performed by the addition of ammonium salt selected from the group consisting of ammonia sulfate and ammonia hydroxide.
14. The hydrometallurgical process according to claim 1 wherein the elution of at least one of Nickel or Cobalt is carried out in the presence of an acid selected from at least one of the group consisting of sulfuric acid, chloridric acid and nitric acid.
15. The hydrometallurgical process according to claim 14 wherein said acid is at a concentration of about 0.5 to 4M.
16. The hydrometallurgical process according to claim 1 wherein the resin is regenerated after elution.
17. The hydrometallurgical process according to claim 16 wherein Na+ and Ca 2+ ions are further included as mobile ions.