A process for leaching minerals that contain metal sulphides and one or more precious metals or precious metal compounds, the process comprising the steps of a first leaching step to leach the minerals under oxidative conditions at a pH of less than 4 to form a slurry or pulp, the slurry or pulp comprising a solid phase containing unreacted components, solid reaction products and elemental sulphur, and subjecting the slurry or pulp or solid residue from the first leaching step to a second leaching step comprising oxidative leaching at pH of at least 9.0 to thereby form thiosulphate, whereby the thiosulphate leaches precious metal from the solid residue.

A method for separating at least two metals from each other in a metal refining process, the method comprising: injecting a feed solution comprising the metals into a column or flow pipe comprising a monolithic solid body having a plurality of channels; and flowing the feed solution through the plurality of channels in the monolithic solid body to separate the metals.

The present application relates to methods for leaching and extraction of precious metals. For example, the present application relates to methods of leaching gold, palladium and/or platinum from a substance comprising gold, palladium and/or platinum (such as a gold-containing ore or a platinum group metal (PGM) concentrate) using an organic solvent that is water-miscible or partially water-miscible.

A method, and systems in which such method may be practiced, allow for the separation of elemental metals from metal alloy. A metal alloy is atomized to form metal alloy particulates. The metal alloy particulates are exposed to an oxidizing agent, such as chlorine gas in the presence of a salt, such as NaCl, an acid, such as HCl, and water. The resulting solution may be filtered to remove particulates, reduced, filtered, reduced, filtered, and so on. In aspects, the method is used to refine gold alloy by oxidation of elemental sponge gold to gold chloride followed by reduction to pure elemental gold.

The invention discloses a cost-effective method for recovering precious metals in circuit board components, and belongs to the area of waste resource recovery. The method mainly solves the problem of selective recovery of precious metals in chlorination leachate, utilizes the basic principle of oxidation-reduction reaction, adopts a mixed solution of sulfuric acid and hydrogen peroxide and a mixed solution of hydrochloric acid, sodium chloride and sodium chlorate, and also adopts ammonia water and formaldehyde to reduce silver. According to the characteristic that the redox potential of gold and palladium ions is higher, the gold and palladium ions in the chlorination leaching solution are selectively reduced into elements by using a reducing agent which is low in price and moderate in reducibility, then the elements are separated through filtration to realize resource recycling. The whole recycling process is greatly shortened, combined with the lower price of reducing agents, leading to the low cost of process. The method is commercially viable and is beneficial to industrialization. Meanwhile, a large amount of tail liquid is prevented from being generated to pollute the environment in the recycling process.

Ways of obtaining a mineral rich powder from an electronic waste substrate include a shredder configured to receive the electronic waste substrate and process the electronic waste substrate into a plurality of fragments. A mill is provided that includes a container configured to receive the plurality of fragments, the container including a milling media, the mill configured to abrade the plurality of fragments with the milling media to produce a milled product. A separator is provided that is configured to receive the milled product, where the separator is configured to apply a predetermined size selection to the milled product to provide a first output including a plurality of particles and a second output including a plurality of abraded fragments. A skid is coupled to and provides structural support for the shredder, the mill, and the separator.

A method of treating process water of a flotation plant is disclosed. The flotation plant comprises a mineral flotation line and a process water circuit for treating underflow and/or overflow of the flotation line. The process water circuit comprises a gravitational solid-liquid separator for dewatering underflow and/or overflow of the mineral flotation line to separate sediment from supernatant comprising at least water and unrecovered fine particles comprising valuable material; and a recover water tank for collecting process water. According to the method, prior to leading supernatant from the gravitational solid-liquid separator into the recover water tank, it is subjected to cleaning flotation, in which at least 90% of the flotation gas bubbles have a size from 0.2 to 250 μm, in a cleaning flotation unit. An arrangement for treating process water of a flotation plant, and its use are also disclosed.

A method, and systems in which such method may be practiced, allow for the separation of elemental metals from metal alloy. A metal alloy is atomized to form metal alloy particulates. The metal alloy particulates are exposed to an oxidizing agent, such as chlorine gas in the presence of a salt, such as NaCl, an acid, such as HCl, and water. The resulting solution may be filtered to remove particulates, reduced, filtered, reduced, filtered, and so on. In aspects, the method is used to refine gold alloy by oxidation of elemental sponge gold to gold chloride followed by reduction to pure elemental gold.

In an activated carbon for adsorbing a noble metal from an aqueous solution containing the noble metal, the difference (absolute value) between a zeta-potential in a 10 mmol/L aqueous solution of sodium tetraborate and a zeta-potential in a 0.01 mmol/L aqueous solution of sodium tetraborate is adjusted to not more than 18 mV and the pore volume of pores with a pore radius of not more than 1 nm is adjusted to 150 to 500 mm.sup.3/g. The activated carbon of the present invention may have a carbohydrate solution decolorizing performance of not less than 30%. The aqueous solution containing the noble metal may be a plating wastewater. According to the present invention, a noble metal can efficiently be adsorbed (or recovered) from a solution containing the noble metal.

The invention relates to a metal sheet which has a plurality of parts to be plated, a frame part and connector parts connecting the parts to be plated and the frame part and in which the plurality of the parts to be plated, the frame part and the connector parts are made of a metal.