Materials and methods for extracting metals from solutions, involving a polymer of Formula A are described:

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where each X is independently either S or O, and n is an integer greater than 1.

A solution for leaching metals from clay containing ore and a method of leaching ore is described. The solution comprises a cyanide; a wetting agent; and a clay stabilizing polymer.

A solution for leaching metals from clay containing ore and a method of leaching ore is described. The solution comprises a cyanide; a wetting agent; and a clay stabilizing polymer.

Presented herein is a ligand-assisted elution chromatography process for the separation of metal ions using a sorbent. In particular, the present invention discloses a process of two sets of column system in combination with two sets of eluting ligand solutions to prepare substantially pure rare earth elements, wherein the first set of column comprises strong acid cation exchange resins and the second set of chromatographic columns comprises hydrous polyvalent metal oxide selected from the group consisting of TiO.sub.2, ZrO.sub.2, or SnO.sub.2 and wherein ligand of said second ligand solution coordinates with said hydrous polyvalent metal oxide.

A method for recovering at least one precious metal from an aqueous solution containing the metal and particularly to recovery of silver and optionally one or more other precious metals from overflow of a sedimentation unit such as a thickener, a clarifier or a pond includes subjecting the aqueous solution to a micro and/or nanobubble flotation, wherein the pH of the aqueous solution is at most 1.5.

A method for recovering at least one precious metal from an aqueous solution containing the metal and particularly to recovery of silver and optionally one or more other precious metals from overflow of a sedimentation unit such as a thickener, a clarifier or a pond includes subjecting the aqueous solution to a micro and/or nanobubble flotation, wherein the pH of the aqueous solution is at most 1.5.

A vertical autoclave according to an embodiment of the present disclosure is a vertical autoclave including an inlet port through which a process solution is introduced, an outlet port through which the process solution is discharged, an oxygen inlet port through which oxygen is supplied to the process solution, an agitator configured to mix the process solution, an inner wall, an acid-resistant brick layer lined on a lower portion and a side portion of the inner wall, and an acid-resistant metal layer lined on an upper portion of the inner wall. A method of removing salt from an autoclave includes raising a surface level of a solution in the autoclave from a first level to a second level such that salt in the autoclave is immersed in the solution, and maintaining the surface level of the solution at the second level. The salt is dissolved in the solution while the surface level of the solution is maintained at the second level.

A vertical autoclave according to an embodiment of the present disclosure is a vertical autoclave including an inlet port through which a process solution is introduced, an outlet port through which the process solution is discharged, an oxygen inlet port through which oxygen is supplied to the process solution, an agitator configured to mix the process solution, an inner wall, an acid-resistant brick layer lined on a lower portion and a side portion of the inner wall, and an acid-resistant metal layer lined on an upper portion of the inner wall. A method of removing salt from an autoclave includes raising a surface level of a solution in the autoclave from a first level to a second level such that salt in the autoclave is immersed in the solution, and maintaining the surface level of the solution at the second level. The salt is dissolved in the solution while the surface level of the solution is maintained at the second level.

A process for recovering chromium from hexavalent chromium-containing wastewater comprises the following steps: (1) extracting hexavalent chromium in wastewater to an organic phase by using an extracting agent, and separating hexavalent chromium from a water phase, so as to acquire a hexavalent chromium-loaded organic phase; (2) reducing the hexavalent chromium-loaded organic phase by using an aqueous solution of an organic reducing agent, reducing hexavalent chromium into trivalent chromium, reversely extracting trivalent chromium into the water phase, and separating the organic phase from the water phase to acquire a solution of the trivalent chromium and a renewable organic phase, wherein the organic reducing agent is one or a mixture of alcohols, aldehydes and carboxylic acids having the carbon atom number ranging 1 to 3; and (3) performing solvent evaporation on the solution of trivalent chromium, catalyzing, and recovering the trivalent chromium.

A process for recovering chromium from hexavalent chromium-containing wastewater comprises the following steps: (1) extracting hexavalent chromium in wastewater to an organic phase by using an extracting agent, and separating hexavalent chromium from a water phase, so as to acquire a hexavalent chromium-loaded organic phase; (2) reducing the hexavalent chromium-loaded organic phase by using an aqueous solution of an organic reducing agent, reducing hexavalent chromium into trivalent chromium, reversely extracting trivalent chromium into the water phase, and separating the organic phase from the water phase to acquire a solution of the trivalent chromium and a renewable organic phase, wherein the organic reducing agent is one or a mixture of alcohols, aldehydes and carboxylic acids having the carbon atom number ranging 1 to 3; and (3) performing solvent evaporation on the solution of trivalent chromium, catalyzing, and recovering the trivalent chromium.