Provided is a method for producing metal microparticles in which the ratio of crystallite diameter to the particle diameter of the metal microparticles is controlled. At least two types of fluid to be processed are used, including a metal fluid in which a metal or a metal compound is dissolved in a solvent, and a reducing agent fluid which includes a reducing agent. Sulfate ions are included in one or both of the metal fluid and the reducing agent fluid. The fluid to be processed is mixed in a thin film fluid formed between at least two processing surfaces, at least one of which rotates relative to the other, and which are disposed facing each other and capable of approaching and separating from each other, and metal microparticles are precipitated. The present invention is characterized in that at this time, the ratio (d/D) of the crystallite diameter (d) of the metal microparticles to the particle diameter (D) of the metal microparticles is controlled by controlling the molar ratio of metal and sulfate ions in the mixed fluid to be processed.

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.

A process for bio-oxidation of sulfides in mineral ore having a metal such as gold occluded or dispersed within the ore as a sulfide is disclosed. The first step comminutes the ore into particles with a size distribution having a P80 of less than 0.25 inch with minus 106 micron particles in the range of 15% to 40% by weight. Agglomerates are formed by adding to the comminuted ore particles an acidic inoculate solution including water, with the solution further including microorganisms capable of bio-oxidizing the sulfides. The agglomerates are then placed in at least one bio-reactor containment vessel to form an ore bed. The process continues by bio-oxidizing the sulfides in the ore bed; then re-circulating the solution through the ore bed, and continuing the bio-oxidation until a desired bio-oxidation level is achieved. Thereafter, the metal is recovered from the ore.

A process for recovery of precious metals from ores or concentrates containing refractory carbonaceous material by cyanidation leaching. The process involves addition to the ores or concentrates at least one cationic surfactant before or during the addition of cyanide-containing solution. The agent enables the recovery of precious metals by cyanidation from high preg-robbing carbonaceous ores and improves the recovery of precious metals by cyanidation from medium to low preg-robbing carbonaceous ores. The agent also prevents froth and foaming formation during the cyanidation process.

A unique sequence of steps is provided to reduce contaminants along one or more surfaces and faces of gold evaporative sources without deleteriously impacting the structure of the gold evaporative sources. Edges are deburred; contaminants are successfully removed therealong; and surface smoothness is substantially retained. The resultant gold evaporative source is suitable for use in evaporative processes as a precursor to gold film deposition without the occurrence or a substantial reduction in the likelihood of spitting by virtue of significantly reduced levels of contaminants, in comparison to gold evaporative sources subject to a standard cleaning protocol.

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 hydrometallurgical process for the treatment of polymetallic ores and sulphide concentrates of copper and zinc, and by-products of lead and zinc from smelting plants, treated independently and/or as mixtures thereof, which contain relevant amounts of lead, copper, zinc, iron, gold and silver, such as the matte-speiss mixture of lead foundries, and copper cements from the purification processes of electrolytic zinc plants. Thee process allows the recovery of metallic copper, zinc, copper as copper and zinc basic salts, which may be hydroxides, carbonates, hidroxysulphates or mixtures thereof; the production of stable arsenic residues; and the effective and efficient recovery of Pb, Au and Ag as a concentrate of lead sulphide and/or lead, Au, and Ag sulphate.