Methods of recovering precious metals from unconventional feed water sources. In approaches, the methods use a combination of one or more of ultrafiltration, nanofiltration, and/or reverse osmosis membranes. The unconventional feed water source may be salt lake brines, coal-fired plant flue-gas scrubber blowdown water, high salinity brines, concentrated brine from desalination of seawater and the like sources. The recovered precious metals may include gold tetrachloride, gold sulfate, silver tetrachloride, silver sulfate, rare earth elements, or mixtures thereof.

The present invention relates to a process for dissolving metals in perhalide containing ionic liquids, and to the extraction of metals from mineral ores; the remediation of materials contaminated with heavy, toxic or radioactive metals; and to the removal of heavy and toxic metals from hydrocarbon streams.

Disclosed are leaching aids and methods of using the leaching aids. The leaching aids can include one or a combination of compounds. The methods of using the leaching aids can include a process of recovering metal from ore, for example, a process involving leaching, concentration and purification unit operations.

The present invention relates to a method for dissolving metals by photocatalysis. A metal-containing material to be dissolved is dispersed in a mixed solution of photocatalyst-containing cyanide and organic chloride; then, a photocatalyst is added; next, an oxygen-containing gas or a substance which is capable of generating oxygen is introduced; and irradiation is applied for a period of time to dissolve metals. Compared with the prior method, the present invention is advantageous in moderate reaction condition, energy conservation, environmental protection, low cost, and convenient operation, and is suitable for mass industrial treatment on metal dissolution.

A process for recovering a precious metal from a precious metal containing article or composition is disclosed. The process comprises treating the precious metal containing article or composition with an oxidant composition under conditions to oxidise the precious metal in the precious metal containing article or composition to obtain a precious metal salt composition. The precious metal salt composition is then contacted with a sorbent under conditions to adsorb at least some of the precious metal salt to the sorbent to obtain a laden sorbent. At least some of the precious metal is then recovered from the laden sorbent. Alternatively, the precious metal is recovered from the precious metal salt composition by chemical reduction, electrochemical reduction and/or chemical precipitation.

A method of recovering gold and copper from a sulfide ore includes (a) removing valuable fines from a product stream from a comminution circuit, such as a crushing and milling circuit, for run of mine ore and producing a valuable fines concentrate stream and (b) processing the remaining comminution product stream after valuable fines removal and producing a valuable coarse concentrate stream.

A process for recovering gold from a refractory gold ore, comprising the steps of: electrolyzing a mixture consisting of the ore particles and an aqueous bromide solution in an electrolytic cell having anode and cathode, wherein bromine is produced at the anode by oxidation of the bromide, thereby dissolving gold in the aqueous phase; separating the ore particles from the aqueous phase to obtain a leach liquor; adjusting the pH of the leach liquor to the alkaline range to produce a gold-containing precipitate; collecting the gold-containing precipitate and recycling a bromide-containing barren solution for reuse as an aqueous bromide feed solution.

Process for gold and/or platinum group metals heap leaching comprising irrigating a heap with an irrigation solution containing sodium cyanide for leaching gold and/or platinum group metals from a gold and/or platinum group metals containing ore. A lime reagent is added by feeding a fine particle lime suspension containing lime particles in an aqueous phase in an irrigation solution.

Methods and apparatus for liquid/solid separation for use in applications such as dewatering fine particulate solids, and recovery of valuable metals from ore in a leaching process are provided. One application relates to methods of agitation leaching of metals such as gold from gold-bearing feedstock. A slurry is formed in a tank by agitation, and allowed to settle. A filter bed forms to drain the liquid from the tank, and a vertical screen pipe such as a well point addresses the formation of an impervious film on the upper surface of the filter bed.

THIS invention relates a method for processing a sulphide ore containing metal values comprising the integration of a sand heap leach (10) and a flotation process (12), providing a method which is suited to processing ores with significant quantities of leachable sulphides. The method includes a comminution step (14), and the classification of the comminuted ore into an oversize coarse fraction (16), a fine fraction (18) suitable for fine flotation and optionally an intermediate fraction (20) suitable for coarse flotation. A concentrate (30) containing iron sulphides from a fine flotation step (22) and optionally a concentrate (36) from a coarse flotation step (34) are blended with the oversize coarse fraction (16), to obtain a blended ore (39) is stacked and subjected to a heap leach process (40).