A method of recovering gold and copper from a sulfide ore includes (a) removing valuable fines from a product stream from a comminution circuit, such as a crushing and milling circuit, for run of mine ore and producing a valuable fines concentrate stream and (b) processing the remaining comminution product stream after valuable fines removal and producing a valuable coarse concentrate stream.

The recovery of noble metal(s) from noble-metal-containing material is generally described. The noble metal(s) can be recovered selectively, in some cases, such that noble metal(s) is at least partially separated from non-noble-metal material within the material. Noble metal(s) may be recovered from noble-metal-containing material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and/or another source of nitrate ions and at least one supplemental acid, such as sulfuric acid, phosphoric acid, and/or a sulfonic acid. The amount of nitrate ions within the mixture can be, in some instances, relatively small compared to the amount of supplemental acid within the mixture. In some cases, the recovery of noble metal(s) using the acid mixtures described herein can be enhanced by transporting an electric current between an electrode and the noble metal(s) of the noble-metal-containing material. In some cases, acid mixtures can be used to recover silver from particular types of scrap materials, such as scrap material comprising silver metal and cadmium oxide and/or scrap material comprising silver metal and tungsten metal.

The invention discloses a measurement apparatus for measuring a volume of a desired solid component in a sample volume of a solid-liquid slurry. The sample volume of the slurry is received into a receptacle and screened to separate out the desired solid component from a remainder of the slurry, whereby the solid component is retained in the receptacle to form a bed therein and the remainder is exhausted. The height of the bed is subsequently measured by a laser being adapted to emit a laser beam into the receptacle, thereby enabling a determination of a volume and/or mass of the solid component retained in the receptacle. The invention further discloses a control system for a leaching plant utilising the measurement apparatus.

Process for recovering one or both of copper and silver from a sulphidic feed containing iron, arsenic, copper and silver by pressure oxidizing an aqueous feed slurry of the sulphidic feed in a pressure vessel to form a liquid phase containing free sulphuric acid and aqueous copper sulphate, and to precipitate arsenic as solid iron arsenic compounds. The process includes operating the pressure vessel at a sufficiently low solids content to maintain a free acid level below 30 g/L in the liquid phase, and providing sufficient heat to maintain a temperature in the pressure vessel above 200° C. Copper metal is recovered from the liquid phase and/or silver may be recovered from the solids by cyanide leaching without the need for a jarosite destruction step.

The present disclosure provides Molecularly Imprinted Polymer (MIP) technology for selectively sequestering one or more target molecules from chemical mixtures. Also disclosed herein are MIP beads and methods of making and using thereof.

A method for removing sulfate iron-containing compounds from a low- to moderate-temperature metal sulfide leach circuit (1) is disclosed. A reactor (6) within a chloride leach circuit (5) and which is preferably maintained at a temperature between 20 and 150 degrees Celsius may be provided with a catalyst (4) comprising a material selected from the group consisting of: colloidal hematite, colloidal goethite, particulate containing FeOOH, particulate containing α-FeOOH, particulate containing γ-FeOOH, particulate containing Fe.sub.2O.sub.3, particulate containing α-Fe.sub.2O.sub.3, particulate containing γ-Fe.sub.2O.sub.3, particulate containing Fe.sub.3O.sub.4, particulate containing Fe(OH)SO.sub.4, and a combination thereof. The catalyst (4) may also be used with heap leach and/or dump leach circuits (22), without limitation. Methods for using and generating the catalyst (4) are also disclosed. In some embodiments, the catalyst (4) may be used as an anti-frothing agent (e.g., for zinc leaching, without limitation).

Provided are a method for recovering gold, in which gold is recovered from a solution containing a gold cyano complex using a crosslinked resin containing a vinyl amine unit, by which gold can be efficiently recovered from the solution not only in a case (A) where a concentration of the gold cyano complex in the solution is low but also in a case (B) where another metal is dissolved in the solution; a method for recovering gold, in which the crosslinked resin and the solution are brought into contact with each other to separate the crosslinked resin and the solution from each other, by which gold can be efficiently recovered from the solution not only in the case (A) but also in the case (B); and a gold recovery facility comprising: a container inside which the crosslinked resin is accommodated in a flowable manner; and a device which feeds the solution to the container, by which gold can be efficiently recovered from the solution not only in the case (A) but also in the case (B).

This disclosure provides a method of improving gold recovery in a cyanide leaching circuit comprising a gold ore slurry. The method includes the step of providing a gold recovery additive chosen from polyacrylic acid, copolymers of acrylic acid and a sulfonated co-monomer, and combinations thereof, wherein the additive has a weight average molecular weight of from about 500 to about 10,000 g/mol. The method also includes the step of combining the gold recovery additive with the gold ore slurry in the cyanide leaching circuit, wherein the gold recovery additive is present in an amount of from about 10 to about 1000 g per ton of dry gold ore to improve the recovery of gold from the gold ore slurry.

The invention provides a process for recovering precious metal from an aqueous solution comprising thiosulfate and at least one precious metal selected from gold and silver, the process comprising: introducing a soluble reducing agent to the aqueous solution in excess of any oxidants present in the aqueous solution; contacting the aqueous solution with a cementation substrate comprising a metallic composition comprising a base metal, wherein the precious metal is reduced in the presence of the reducing agent and the cementation substrate so that reduced precious metal deposits on the cementation substrate to form a precious metal cementation product; separating the precious metal cementation product from a precious metal-lean aqueous solution comprising the thiosulfate; and recovering precious metal from the precious metal cementation product.

The recovery of noble metal(s) from noble-metal-containing material is generally described. The noble metal(s) can be recovered selectively, in some cases, such that noble metal(s) is at least partially separated from non-noble-metal material within the material. Noble metal(s) may be recovered from noble-metal-containing material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and/or another source of nitrate ions and at least one supplemental acid, such as sulfuric acid, phosphoric acid, and/or a sulfonic acid. The amount of nitrate ions within the mixture can be, in some instances, relatively small compared to the amount of supplemental acid within the mixture. In some cases, the recovery of noble metal(s) using the acid mixtures described herein can be enhanced by transporting an electric current between an electrode and the noble metal(s) of the noble-metal-containing material. In some cases, acid mixtures can be used to recover silver from particular types of scrap materials, such as scrap material comprising silver metal and cadmium oxide and/or scrap material comprising silver metal and tungsten metal.