A process for recovering gold from a gold-containing raw material, comprising leaching the gold-containing material with an aqueous solution comprising elemental bromine and bromide source to form a pregnant leach solution with the gold dissolved therein; separating said pregnant leach solution from the gold-depleted raw material, removing elemental bromine from said pregnant leach solution, extracting the gold from the pregnant leach solution in an acidic environment into an organic extractant, to form a gold-loaded extract and bromide-containing raffinate, stripping the extract with an alkaline aqueous solution to form a gold-bearing aqueous solution, generating gold (Au.sup.0) and treating bromide-containing stream(s) to produce recyclable elemental bromine.

Systems and methods for the recovery of silver are generally described. Certain embodiments are related to innovations newly developed within the context of the present invention that exploit the ability of elemental silver (i.e., silver metal in an uncharged, unreacted state—and in certain cases, in relatively high purities) to be recovered from liquids (e.g., suspensions and/or solutions) containing non-elemental silver (i.e., silver ions, silver salts, silver complexes, silver compounds, etc.), by exposing the non-elemental silver to certain reducing agents.

A method for removing sulfate iron-containing compounds from a low- to moderate-temperature metal sulfide leach circuit (1) is disclosed. A reactor (6) within a chloride leach circuit (5) and which is preferably maintained at a temperature between 20 and 150 degrees Celsius may be provided with a catalyst (4) comprising a material selected from the group consisting of: colloidal hematite, colloidal goethite, particulate containing FeOOH, particulate containing α-FeOOH, particulate containing γ-FeOOH, particulate containing Fe.sub.2O.sub.3, particulate containing α-Fe.sub.2O.sub.3, particulate containing γ-Fe.sub.2O.sub.3, particulate containing Fe.sub.3O.sub.4, particulate containing Fe(OH)SO.sub.4, and a combination thereof. The catalyst (4) may also be used with heap leach and/or dump leach circuits (22), without limitation. Methods for using and generating the catalyst (4) are also disclosed. In some embodiments, the catalyst (4) may be used as an anti-frothing agent (e.g., for zinc leaching, without limitation).

Methods for producing silver nanostructures with improved dimensional control, yield, purity, monodispersity, and scale of synthesis.

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.

Methods of enhancing recovery of value sulfide and/or precious metal-bearing minerals from an ore containing such minerals as well as Mg-silicate, slime forming minerals, and/or clay by adding a froth phase modifier agent to the ore, and subjecting the ore to a froth flotation process performed under acidic conditions, are provided herein.

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.

Desirable methods for larger scale silver nanoplate synthesis are described along with methods for applying a noble metal coating onto the silver nanoplates to form coated silver nanoplates with a desirable absorption spectrum. The silver nanoplates are suitable for use in coatings for altering the hue of a transparent film. The hue adjustment can be particularly desirable for transparent conductive films.

Ion exchange resin macroporous beads for the highly selective extraction of univalent anions from aqueous solutions. A specific example is the removal of dicyanoaurate and dicyanoargentate from cyanide leach solutions and tailings. The beads have a maximum number of ligands specific for the desired univalent anion, while maintaining sufficient separation to minimize binding of polyvalent ions. The beads are prepared using a functionalized monomer with the use of a specifically tuned coordinator. The beads can be used as a sensor for detecting the amount of anions captured when interrogated by an appropriate light source.

This invention relates to a hydrometallurgical process for the recovery and separation of valuable precious, base or rare elements such as platinum group metals (PGMs), gold or silver, and other valuable base and rare metals such as nickel, cobalt, copper, rare earth elements (REE), yttrium and scandium, as well as uranium, thorium, manganese, zinc, cadmium, molybdenum, titanium, tin, and other minor elements such as vanadium, germanium and gallium from a feed material comprising ores, concentrates and other materials. In particular, the process comprises quantitative removal of additional base, rare and gangue elements for increased efficiency of further treatment of the solids for valuable metals recovery and/or recycling and/or separation of valuable metals from pressure leach residue and may be integrated into one or more existing valuable element extraction processes.