Abstract: Provided is a process for recovery of gold from gold-bearing raw materials comprising (a) leaching said gold-bearing raw material in a chloride containing leaching solution containing a total concentration of less than 120 g/L of halide ions, whereby the total concentration of chloride ions is less than 120 g/L of to dissolve gold and to obtain a leach solution comprising gold in solution; and simultaneously contacting the leach solution comprising gold in solution with a re-sorptive material to obtain a leach solution comprising gold-bearing re-sorptive material; and (b) recovering gold and optionally silver from the said gold-bearing re-sorptive material.

Abstract: A water treatment system using electrocoagulation is provided. One of the stages of the water treatment is subjecting the water to electrocoagulation so that colloidal solids can be reduced, emulsions broken, and hydrocarbons and complex organics removed, without the application of substantial chemical substances to the contaminated water or even the use of any chemical substances. An electrocoagulation apparatus can comprise: a tank having a first end and a second end; a plurality of electrolytic cells provided in the tank, each electrolytic cell having at least one anode electrode and at least one cathode electrode defining an anode/cathode electrode pair; and a voltage supply connected to each electrolytic cell to supply a voltage across each anode/cathode pair.

Abstract: An activated carbon regeneration method of the present invention is for eluting gold from activated carbon on which the gold has been adsorbed and thereafter recycling, in adsorption of the gold, the used activated carbon from which the gold has been eluted, the method including: washing the used activated carbon with an acidic washing liquid, alkaline washing liquid or neutral washing liquid; and when the used activated carbon is washed with the acidic washing liquid, keeping the acidic washing liquid after the washing in an acidic region, or when the used activated carbon is washed with the alkaline washing liquid or neutral washing liquid, keeping the alkaline washing liquid or neutral washing liquid after the washing in an alkaline region or neutral region.

Abstract: The present invention relates to a pipe comprising first and second parts of electrically conducting material. The parts are electrically insulated from each other and are arranged on the inside surface of the pipe, extending substantially in the longitudinal direction of the pipe.

Abstract: The present invention relates to a process for chemical extraction of gold and silver from low grade and refractory pyritic concentrates containing minimum 1 ppm Au, by their leaching in enameled cast iron reactors, steel plated lead or plastic coated steel, at room temperature, in ammoniac solutions (pH 8-10) of sodium thiosulfate (50-60 g/l Na2S2O3. 5 H2O) with a divalent copper salt as catalyst (3-4 g/l Cu). The suspension resulting after 2-4 hours of reaction is filtered. The thiosulfate solution containing minimum 5 mg/l undergoes an electrolysis process with insoluble anodes. Copper, gold and silver is deposited in the cell as a sludge, and the electrolyte having a maximum content of Au of 1 mg/l, is recycled to the leaching operation of raw material, after correction of copper content and alkalinity to the baseline values.

Abstract: A process for reducing the concentration of perchlorate in an aqueous concentrated multi-component salt solution comprising treating the salt solution with an amphoteric ion-exchange resin to provide an adsorbed perchlorate and multi anion-containing resin and a perchlorate depleted solution; and removing the perchlorate depleted solution. The multi-anion are selected from chloride, chlorate, perchlorate, sulphate, and dichromate, present in electrolytic processes for the production of sodium chlorate.

Abstract: The present invention provides a method for manufacturing silver triangular pyramid particles including: forming an electric field in an electrolytic solution including silver ions and a surfactant to reduce the silver ions into silver triangular pyramid particles.

Abstract: Apparatus and processes are disclosed for electrowinning metal from a fluid stream. A representative apparatus comprises at least one spouted bed reactor wherein each said reactor includes an anolyte chamber comprising an anode and configured for containing an anolyte, a catholyte chamber comprising a current collector and configured for containing a particulate cathode bed and a flowing stream of an electrically conductive metal-containing fluid, and a membrane separating said anolyte chamber and said catholyte chamber, an inlet for an electrically conductive metal-containing fluid stream; and a particle bed churning device configured for spouting particle bed particles in the catholyte chamber independently of the flow of said metal-containing fluid stream. In operation, reduced heavy metals or their oxides are recovered from the cathode particles.

Abstract: Provided are a low impedance gold electrode, which has increased surface area, and can improve a bonding force with other materials, an apparatus for and a method of fabricating the low impedance gold electrode, and an electrolyte solution for use in the fabrication of the low impedance gold electrode. The gold electrode has a surface roughness that is increased through electrolysis using an acid electrolyte solution, has an impedance that is less than 1/10 of an impedance before the electrolysis and is higher than 0? when the low impedance gold electrode is disposed in the acid electrolyte solution or another electrolyte solution, and has a single-layered structure whose thickness is less than that before the electrolysis.

Abstract: A method of preparing organic acids (fulvic, humic, and ulmic) for use as an electrolyte for producing high ionizations of precious metals (such as silver) which entails leaching out the organic acid from its source, stabilizing the organic acid first with ascorbic acid followed by sodium benzoate, removing cations, and using the organic acid as an electrolyte. A precious metal (such as silver) is used as a sacrificial electrode in this electrolyte. A non-sacrificial electrode could either be the same precious metal or an inert non-precious metal (titanium or graphite carbons). If the same material is used for the non-sacrificial electrode as for the sacrificial electrode, the size of each electrode may be about the same. If different material is used for the non-sacrificial electrode, its size should be larger that of the sacrificial electrode. Current at about 2 or more volts is applied to the electrodes and the ionization process begins yielding high concentrations of ionized precious metals.

Abstract: A process for purifying and refining platinum group metals such as platinum, iridium, palladium, rhodium and the like by an electrochemical process using ammonium chloride as the electrolyte to form ammonium chloride platinum group salts as a "slime" followed by the use of ammonia hydroxide to dissolve and separate said salts from other materials in the slime. A further step to precipitate the platinum metals from the ammonia hydroxide may be employed.

Abstract: In the recovery of an electrically conductive metal from a liquid containing the metal in solution, a cathode member for deposition of the metal by electrolysis, comprises a carrier sheet with a cathode element of the metal to be recovered, on one side of the sheet; the carrier sheet is of a material from which the metal is readily refinable when smelted with the carrier sheet; the cathode member has particular application for removal of the silver content of fixer solution in photography; suitably the sheet is flexible and has a memory of a planar state, such that on being rolled into a cylindrical tubular configuration, it returns to the planar state unless restrained.

Abstract: An electrochemical cell is provided for removal of metals such as copper, lead, silver, tellurium, platinum, palladium or nickel from dilute solutions of the metal. The cell comprises a porous tubular support (18) which is provided with a cathode comprising a porous carbon fiber material (19), a current feeder (15) for the cathode, a tubular anode (12) spaced from said cathode, a current feeder (16) for the anode, the anode and the cathode being enclosed by a non-porous outer casing (11). In use the dilute solution from which the metal is to be removed is introduced into the cell through an inlet (13) and flows through the porous carbon fiber cathode to an outlet (14). The cell is useful for removing harmful metals from wastes so that they are environmentally acceptable for disposal and for recovery of valuable metals.

Abstract: A process for leaching gold, silver, platinum and palladium wherein an aqueous leaching solution containing bromine and bromide ion contacts a precious metal source to produce an aqueous leachate. A precursor composition for producing an aqueous leaching solution for leaching gold, silver, platinum and palladium. A process for electrogenerating bromine and a process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated and contacts a precious metal source to produce an aqueous leachate. A process for leaching gold, silver, platinum and palladium wherein bromine is electrogenerated from a solution containing chloride ions and bromide ions.

Abstract: The present invention relates to an electrolytic desilvering method for photographic effluents.This method is carried out in an electrolytic cell comprising at least one anodic compartment and at least one cathodic compartment. The photographic effluent is treated in the cathodic compartment of the cell in order to reduce the silver ions in solution. The electrolyte is then recycled in the anodic compartment before being discharged to the sewer.This recycling in the anodic compartment allows to discharge to the sewer an effluent having a silver content less than 20 ppm.