An environmentally friendly (e.g. no acid, base, or cyanide) system and process for large scale extraction of metal ion into aerobic molten salt (or ionic liquid) and the electrodeposition of metal (e.g. copper, gold, silver, etc.) from the metal ion dissolved in the molten salt. The non-volatile low vapor pressure liquid salt is reusable, and heat from the molten slag can heat the molten salts or ionic liquids. Another embodiment comprises a one-pot apparatus for the extraction of metal (e.g. copper) from metal earths and electrodepositing the metal using a low melting (209 C.) aerated NaKZn chloride salt in which copper metal oxidizes and is converted to soluble copper chloride. When an electrical power supply is connected to the graphite vessel (cathode) and to copper rods in the melt (anodes), then the copper chloride is deposited as copper metal by electroreduction on the bottom of the graphite reaction vessel.

Provided are compositions for removal of a target substance from a fluid stream, the composition comprising a polyamine; and a covalently linked hydrophobic group, wherein the polyamine is covalently linked to a support material. Also provided are processes for removal of a target substance from a fluid stream comprising contacting the fluid stream with a composition comprising a polyamine; and a covalently linked hydrophobic group, wherein the polyamine is covalently linked to a support material.

The present invention relates a method of leaching metals involving the use of thiourea, sodium metabisulfite (SMB), sulfuric acid, and a source of hypochlorite. The method is useful, for example, for leaching metal-containing materials to obtain precious metals (e.g., gold) as well as for purifying base metals (e.g., copper), and for removal of metals from electronic wastes.

An environmentally friendly (e.g. no acid, base, or cyanide) system and process for large scale extraction of metal ion into aerobic molten salt (or ionic liquid) and the electrodeposition of metal (e.g. copper, gold, silver, etc.) from the metal ion dissolved in the molten salt. The non-volatile low vapor pressure liquid salt is reusable, and heat from the molten slag can heat the molten salts or ionic liquids. Another embodiment comprises a one-pot apparatus for the extraction of metal (e.g. copper) from metal earths and electrodepositing the metal using a low melting (209 C.) aerated NaKZn chloride salt in which copper metal oxidizes and is converted to soluble copper chloride. When an electrical power supply is connected to the graphite vessel (cathode) and to copper rods in the melt (anodes), then the copper chloride is deposited as copper metal by electroreduction on the bottom of the graphite reaction vessel.

A method for recovering gold from an ore or a refining intermediate containing gold, comprising a step of contacting a gold-containing raw material obtained from the ore or the refining intermediate with an acidic solution containing a copper ion, an iron ion and a halide ion while supplying an oxidizing agent to leach the gold component in the raw material. The halide ion in the acidic solution is only a bromide ion, wherein the concentration of the bromide ion in the acidic solution is 100 g/L or more or the concentration of the bromide ion in the acidic solution is less than 100 g/L. When the concentration of the bromide ion is less than 100 g/L, a concentration ratio of the halide ion in the acidic solution is such that a ratio of the concentration of the chloride ion to the concentration of the bromide ion is or less.

Disclosed herein is a micro particle with a diameter of 10-100 microns, wherein the micro particle is coated with silver nanoparticles; and wherein the nanoparticles are coated with a polysaccharide; and wherein the polysaccharide coating is digestible by bacteria. Also, disclosed is a method of making silver nanoparticles using an ascorbic acid derivative or an alpha-hydroxyl carboxylic acid derivative as a reducing agent. The silver nanoparticles may be coated onto micro particles, embedded in hydrogel particles or coated with polysaccharide. The silver nanoparticles may be used in a wound dressing, a bandage, a fungal treatment product, a deodorant, a floss product, a toothpick, a dietary supplement, dental X-ray, a mouthwash, a toothpaste, acne or wound treatment product, skin scrub, and skin defoliate agent.

The present disclosure is directed to a process for thiosulfate leaching of a precious metal-containing material and recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin optionally using an eluant comprising trithionate. Various process improvements include maintaining the thiosulfate-containing leach solution substantially free of thiols and amines, maintaining a concentration of a sulfide in the thiosulfate leach solution of no more than about 100 ppm, recycling the barren resin free of contact with a sulfide, bisulfide, and polysulfide, and/or maintaining a concentration of tetrathionates, trithionates, sulfur-oxygen anions, and/or combinations thereof within about 50% of a concentration level of the one or more of tetrathionates, trithionates, sulfur-oxygen anions, the combinations thereof in the precious metal-containing solution before contact with the recycled barren resin.

A method of extracting metals from polymetallic sulphide ores or concentrates comprising at least Cu, Zn, Pb and Ag, comprising a first step of atmospheric leaching in sulphate medium in the presence of recycled silver for extracting Cu and Zn and a second step of atmospheric leaching in chloride medium for extracting Pb and Ag.

The present disclosure provides Molecularly Imprinted Polymer (MIP) technology for selectively sequestering one or more target molecules from chemical mixtures. Also disclosed herein are MIP beads and methods of making and using thereof.

Methods, systems and lixiviation compositions including an ammonium thiosulfate or a non-ammonium thiosulfate component in combination with one or more alkaline earth metal hydroxides, and optionally copper cations, for leaching precious metals from a precious metal containing material. The alkaline earth metal hydroxides may include magnesium hydroxide, calcium hydroxide, or a combination of magnesium hydroxide and calcium hydroxide.