Cognis IP Management Gmbh

Basf Se Corporation

Andrew Nisbett

Gary Alan Kordosky

Hans Christian Hein

Stephen John Adkins

Alexsandro Berger

Ian John Flanagan

The present invention relates to a metal leach and recovery process. The process involves subjecting a metal bearing material to a reactive process by combining said metal bearing material with a leaching agent to liberate at least one metal value and forming a first aqueous leach pulp. This first aqueous leach pulp is subjected to a solid liquid separation step thereby providing a first clarified aqueous leach solution and a second aqueous leach pulp. The first clarified aqueous leach solution is then subjected to solvent extraction thereby obtaining the first aqueous raffinate. The second aqueous leach pulp is subjected to at least two further solid liquid separation steps of which some or all are in a counter current decantation (CCD) arrangement. Each of the solid liquid separation steps of the CCD arrangement results in an aqueous liquor and aqueous suspension of solids wherein each aqueous suspension of solids resulting from each solid liquid separation step of the CCD arrangement is passed to the subsequent solid liquid separation step and the suspension of solids resulting from the final solid liquid separation step is removed from the process. Further, each aqueous liquor resulting from each solid liquid separation step of the CCD arrangement is passed to the previous solid liquid separation step. The further solid liquid separation steps result in at least one further clarified aqueous leach solution. The at least one further clarified aqueous leach solution is/are subjected to solvent extraction thereby obtaining at least one further aqueous raffinate. At least a portion of the one or more of the at least one further aqueous raffinates is fed into the final solid liquid separation is of the CCD arrangement. The process provides a flocculation system comprising either: (i) addition of an organic polymeric flocculant to or prior to at least one solid liquid separation step, which polymeric flocculant is formed from 2-acrylamido-2-methylpropane sulphonic acid (ATBS) or salts thereof as a homopolymer or copolymer with at least one water-soluble ethylenically unsaturated monomer; or (ii) addition of an organic polymeric flocculant and at least one support agent to or prior to at least one solid liquid separation step, which at least one support agent is selected from at least one of the group consisting of oxidizing agents, reducing agents, irradiation and free radical producing agents. The process provides significantly improved metal extraction and recovery.

Metal leach and recovery process

Processes for metal leaching/solvent extraction are described which comprise: (a) providing a first aqueous leach pulp which comprises a mixture of leached solids and an aqueous leach solution comprising a metal, a leaching agent and water; (b) subjecting the first aqueous leach pulp to a first solid-liquid separation to provide a first clarified aqueous leach solution and a second aqueous leach pulp, wherein the second aqueous leach pulp comprises the leached solids at a % solids level greater than the first pulp; (c) subjecting the first clarified aqueous leach solution to a first solvent extraction prior to any significant dilution, whereby a first aqueous raffinate is obtained; (d) subjecting the second aqueous leach pulp to a second solid-liquid separation with dilution via an aqueous stream to obtain a second clarified aqueous leach solution; and (e) subjecting the second clarified aqueous leach solution to a second solvent extraction whereby a second is aqueous raffinate is obtained.

Methods for improving the recovery of metal leaching agents

Processes for metal leaching/solvent extraction are described which comprise: (a) providing a first aqueous leach pulp which comprises a mixture of leached solids and an aqueous leach solution comprising a metal, a leaching agent and water; (b) subjecting the first aqueous leach pulp to a first solid-liquid separation to provide a first clarified aqueous leach solution and a second aqueous leach pulp, wherein the second aqueous leach pulp comprises the leached solids at a % solids level greater than the first pulp; (c) subjecting the first clarified aqueous leach solution to a first solvent extraction prior to any significant dilution, whereby a first aqueous raffinate is obtained; (d) subjecting the second aqueous leach pulp to a second solid-liquid separation with dilution via an aqueous stream to obtain a second clarified aqueous leach solution; and (e) subjecting the second clarified aqueous leach solution to a second solvent extraction whereby a second aqueous raffinate is obtained.

The disclosed invention provides a process for enhanced recovery of one or more metal values from heap and/or dump leaching of ores containing the metal values, the process comprising:

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Tucson, AZ, United States of America

Andrew Nisbett