Carbonation and selective leaching for the recovery of metals
The present disclosure is related to carbonation and selective ammonia leaching for the recovery of minor metals.
1 . A method for extracting a target metal from a target metal-containing material, comprising:
exposing the target metal-containing material to carbon dioxide such that the carbon dioxide reacts with target metal associated with the target metal-containing material to form a target metal carbonate, wherein the target metal is a transition metal; and
leaching the target metal carbonate with a leaching agent to separate the target metal from the carbonate anion.
2 . The method of claim 1 , wherein the leaching agent comprises a Lewis base.
3 . The method of claim 1 , wherein leaching the target metal carbonate comprises forming a carbonato-ammine complex of the target metal.
4 . The method of claim 1 , wherein the target metal is a metal capable of coordinating with ammonia to form a metal ammine complex.
5 . The method of claim 1 , wherein the target metal comprises cobalt, nickel, copper, zinc, chromium, silver, gold, and/or platinum group metals.
6 . The method of claim 1 , wherein the target metal has an oxidation state of greater than or equal to +1.
7 . The method of claim 1 , wherein the target metal is a metallic metal having a zero oxidation state.
8 . The method of claim 1 , wherein the target metal-containing material comprises mafic rocks, ultramafic rocks, olivine minerals, pyroxene minerals, and/or serpentine minerals.
9 . The method of claim 1 , wherein the leaching agent is ammonia.
10 . The method of claim 1 , wherein the exposing step is performed at a temperature of greater than or equal to 20° C. and less than or equal to 350° C.
11 . The method of claim 1 , wherein the leaching step is performed at a temperature of greater than or equal to 80° C. and less than or equal to 330° C.
12 . The method of claim 1 , wherein the method is performed in a closed system.
13 . The method of claim 1 , wherein, during the exposing step, a pressure of carbon dioxide is greater than or equal to 100 psi and less than or equal to 5000 psi.
14 . The method of claim 1 , wherein, during the exposing step, the carbon dioxide is gaseous.
15 . The method of claim 1 , wherein the target metal is nickel, copper, cobalt, molybdenum, and/or zinc.
16 . The method of claim 1 , wherein the target metal-containing material further contains a second target metal, and wherein, during the exposing step, the second target metal also forms a carbonate.
17 . The method of claim 1 , wherein the leaching is performed in the presence of a liquid and/or solution comprising the leaching agent.
18 . The method of claim 1 , wherein the leaching is carried out under a pressure of greater than or equal to 0.1 atmospheres absolute and less than or equal to 2 atmospheres absolute.
19 . A method for extracting a target metal from a target metal-containing material, comprising:
exposing the target metal-containing material to carbon dioxide such that the carbon dioxide reacts with target metal associated with the target metal-containing material to form a target metal carbonate, wherein the target metal is a transition metal; and
leaching the target metal carbonate with a leaching agent to separate the target metal from the carbonate anion,
wherein the leaching results in less than 10 wt % of the carbonate material from the target metal carbonate forming carbon dioxide.
20 . A method for extracting a target metal from a target metal-containing material, comprising:
exposing the target metal-containing material to carbon dioxide such that the carbon dioxide reacts with target metal associated with target metal-containing material to form target metal carbonate; and
leaching the target metal carbonate with a leaching agent to separate the target metal from the carbonate anion,
wherein the leaching results in less than 10 wt % of the carbonate material from the target metal carbonate forming carbon dioxide.