A process for roasting of metal concentrate wherein concentrate particles are fed into a roaster where they are thermally treated at a temperature in the range of 500 and 1200° C. in a fluidized bed to form a calcine. At least parts of the calcine are withdrawn from the roaster together with a gas stream as a solid fraction. Concentrate particles with a diameter at least 50% smaller than the average diameter of the concentrate particles are separated as small particles and/or particles from the gas-solid-fraction are separated in at least one step as small calcine particles and/or particles are gained in another hydrometallurgical step as other particles. Defined particles are pelletized, whereby at least 80% of the pellets feature a diameter of at least 80% of the concentrate particles average diameter. The pellets are fed into the roaster.

A process for treating minerals containing metal sulphide and a precious metal, the process comprising fine grinding the minerals and subjecting the minerals to a first leaching step conducted under oxidising conditions at a pH of from 5 to 7, and subjecting a pulp or suspension or solid residue from the first leaching step to a second leaching step conducted under oxidising conditions at a pH of at least 9.0.

A process for recovery of one or more elements, selected from precious metals and chalcophile metals, as herein defined, from materials containing precious and/or chalcophile metal/s, said process including: (i) contacting the material with an alkaline solution containing a lixiviant comprising an amino acid, or derivative thereof, and an alkali stable transition metal complex in order to form a leachate containing the precious metal and/or chalcophile metal; and (ii) recovering the precious metal and/or chalcophile metal from the leachate.

Precious metals such as those of the platinum group can be effectively recovered from crystalline aluminosilicate supports, for example from spent catalysts, without appreciable degradation of the crystal structure by ion-exchange using a base metal ion containing medium and subsequent sequestration of the precious metal in elemental form on a nonionic cross linked borane reducing resin.

A process for the recovery of gold from carbon fines waste, which are produced, especially from carbon-in-leach (CIL) and carbon-in-pulp (CIP) processes. The gold may be eluted from carbon fines with alkaline eluent having a low oxidation reduction potential (ORP). Value added products may be obtained from the extracted carbon fines.

A hydrometallurgical method for simultaneously extracting zinc, lead, silver, iron and calcium from electric arc furnace dust (hazardous waste) produced by the steelmaking industry (steelworks), in the form of industrial products: zinc as zinc sulphate or zinc cathodes; lead and silver as a concentrate of lead and silver; iron as reduced elemental iron for return to the electric arc furnace; and, lastly, calcium as gypsum, without solid waste or liquid effluents being generated relates to the chemical nature of the electric arc furnace dust (complex oxides) changes to a sulfide complex, and eliminating the hazards associated with the generation of fugitive heavy-metal salts. In addition, the hydrometallurgical problem of low recovery of zinc and iron is solved. Consequently, hydrometallurgy is made easier and more environmentally friendly, as condensed water is used as a leachate, the condensed water being continuously regenerated by vacuum evaporation systems without generating effluents.

Adducts, superstructures, and crystalline compositions prepared from a metal halide anion non-covalently bound to the outer surface of a macrocycle and methods for gold recovery are disclosed.

An apparatus for collection of heavier particles such as gold flowing in a river includes a support frame with legs for mounting in the river spaced from the bed with a series of drum mounted on the support frame one behind the other for rotation about an axis transverse to the river flow. The drums have a plurality of blades mounted so that flow of water in the river causes a rotation of the drum, a plurality of water entry openings and a plurality of discharge openings in the drum with the drum shaped such that rotation causes a centrifugal action such that the heavier particles remain within the drum against escape from the drum while lighter particles and water are discharged.

An apparatus for collection of heavier particles such as gold flowing in a river includes a support frame with legs for mounting in the river spaced from the bed with a series of drum mounted on the support frame one behind the other for rotation about an axis transverse to the river flow. The drums have a plurality of blades mounted so that flow of water in the river causes a rotation of the drum, a plurality of water entry openings and a plurality of discharge openings in the drum with the drum shaped such that rotation causes a centrifugal action such that the heavier particles remain within the drum against escape from the drum while lighter particles and water are discharged.

Disclosed is a method for recycling a hydrogen fuel cell of a new energy vehicle, including the following steps of: (1) discharging and disassembling a hydrogen fuel cell in turn to obtain a hydrogen supply system, an air supply system, a cooling system and a galvanic pile; (2) disassembling the galvanic pile into a catalyst and carbon cloth, and ashing to obtain ash; (3) adding an auxiliary agent into the ash, mixing, introducing inert gas, heating, introducing oxidizing gas, and absorbing tail gas by using an ammonium salt solution; and (4) adding a reducing agent into the ammonium salt solution absorbing the tail gas in step (3) to react, filtering, taking and cleaning a filter residue to obtain Pt.