An apparatus for the recovery of gold from a gold-bearing aqueous filtrate, the process comprising the steps of: (A) Contacting the aqueous filtrate with dibutyl carbitol (DBC) in a two-stage solvent extraction process to remove the gold from the aqueous filtrate into the DBC to form a gold-loaded DBC; and (D) Contacting the gold-loaded DBC with an aqueous acid scrub of hydrochloric acid in a four-stage countercurrent scrub process to remove impurities, e.g., non-gold metal, from the DBC into the aqueous scrub solution to form an impurity-loaded aqueous scrub.

Each stage of the solvent extraction circuit and the aqueous acid scrub circuit is equipped with a mixing assembly and a phase separation tank in a head-tail arrangement such that the mixing assembly of one stage is adjacent to the phase separation tank of the adjacent stage.

A recyclable, non-toxic solvent media and methods for precious metal leaching and extraction, in particular platinum group metals (PGMs), are described. The solvent media comprises 3-methoxy-3-methyl-1-butanol (MMB), an oxidizing agent such as lithium bromate, and a halogen salt such as lithium bromide. A precious metal leaching process comprises preparing the solvent media, adding precious metal-containing substance to the solvent media and agitation to leach the precious metal from the substance into the solvent. Agitation may be performed for several hours to days at relatively low temperature. After leaching, filtration is performed to separate the solvent-soluble precious metals from insoluble residues. The method may further comprise refinement of the precious metal and purification of the solvent. Purified solvent may be recycled/reused in solvent media for leaching and extraction of precious metals.

The cost of precious metals, such as gold, makes recovery or recycling of these materials economically viable and desirable. Disclosed herein is a method of recovering gold from waste sources thereof, in particular waste electrical goods. Also disclosed herein is an apparatus for recovering gold from said waste sources. In particular, disclosed herein is a method and apparatus in which gold leaching chlorine gas is generated externally to a reactor vessel and subsequently pumped into the reactor vessel comprising the waste gold materials.

The cost of precious metals, such as gold, makes recovery or recycling of these materials economically viable and desirable. Disclosed herein is a method of recovering gold from waste sources thereof, in particular waste electrical goods. Also disclosed herein is an apparatus for recovering gold from said waste sources. In particular, disclosed herein is a method and apparatus in which gold leaching chlorine gas is generated externally to a reactor vessel and subsequently pumped into the reactor vessel comprising the waste gold materials.

The cost of precious metals, such as gold, makes recovery or recycling of these materials economically viable and desirable. Disclosed herein is a method of recovering gold from waste sources thereof, in particular waste electrical goods. Also disclosed herein is an apparatus for recovering gold from said waste sources. In particular, disclosed herein is a method and apparatus in which gold leaching chlorine gas is generated externally to a reactor vessel and subsequently pumped into the reactor vessel comprising the waste gold materials.

The cost of precious metals, such as gold, makes recovery or recycling of these materials economically viable and desirable. Disclosed herein is a method of recovering gold from waste sources thereof, in particular waste electrical goods. Also disclosed herein is an apparatus for recovering gold from said waste sources. In particular, disclosed herein is a method and apparatus in which gold leaching chlorine gas is generated externally to a reactor vessel and subsequently pumped into the reactor vessel comprising the waste gold materials.

A method for recovery of platinum group metals from a spent catalyst is described. The method includes crushing the spent catalyst to obtain a catalyst particulate material including particles having a predetermined grain size. The method includes subjecting the catalyst particulate material to a chlorinating treatment in the reaction zone at a predetermined temperature for a predetermined time period by putting the catalyst particulate material in contact with the chlorine containing gas. The method also includes applying an electromagnetic field to the chlorine-containing gas in the reaction zone to provide ionization of chlorine; thereby to cause a chemical reaction between platinum group metals and chlorine ions and provide a volatile platinum group metal-containing chloride product in the reaction zone. Following this, the volatile platinum group metal-containing chloride product is cooled to convert the product into solid phase platinum group metal-containing materials.

A method for recovery of platinum group metals from a spent catalyst is described. The method includes crushing the spent catalyst to obtain a catalyst particulate material including particles having a predetermined grain size. The method includes subjecting the catalyst particulate material to a chlorinating treatment in the reaction zone at a predetermined temperature for a predetermined time period by putting the catalyst particulate material in contact with the chlorine containing gas. The method also includes applying an electromagnetic field to the chlorine-containing gas in the reaction zone to provide ionization of chlorine; thereby to cause a chemical reaction between platinum group metals and chlorine ions and provide a volatile platinum group metal-containing chloride product in the reaction zone. Following this, the volatile platinum group metal-containing chloride product is cooled to convert the product into solid phase platinum group metal-containing materials.

A method for recovering precious metal from an acidic aqueous solution containing dissolved precious metal and free chlorine, comprising the following successive steps: (1) combining a salt of a non-precious metal present in a low oxidation state as a solid or as an aqueous solution with the acidic aqueous solution to consume the free chlorine and form an acidic aqueous mixture, and (2) adding non-precious metal to the acidic aqueous mixture formed in step (1) to precipitate elementary precious metal.

This invention relates to a hydrometallurgical process for extracting platinum group metals (PGMs), gold, silver and base metals from a flotation concentrate (10) containing sulphide minerals such as pentlandite and chalcopyrite, along with pyrite and pyrrohotite. The process includes a modified pressure oxidation step (12) to selectively separate base metals into sulphate medium (14), from the PGMs. The modified pressure oxidation step (12) partially or completely oxidizes sulphide minerals to produce a product slurry (14) containing base metal sulphates in solution and a solid residue containing PGMs along with sulphate and elemental sulphur. The solid residue is subjected to a thermal treatment (18) to remove sulphate and elemental sulphur from the solid residue, and to condition the PGMs to be soluble in chloride medium. The treated solid residue is the subjected to PGM recovery by leaching in chloride leaching medium (20) to recover the PGMs.