In one aspect, the present disclosure pertains to methods of making various noble metal nanoprisms, e.g., gold nanoprisms. In various aspects, the methods can comprise incubating, under dark conditions, a growth solution comprising: (a) a plurality of gold seed structures; (b) a gold precursor, and (c) a photocatalytic intermediary, such that the during incubating step multiply-twinned gold seed structures in the growth solution are preferentially enlarged. The disclosed methods can comprise separating the multiply-twinned gold seed structures from the growth solution based upon the size of the gold seed structures to produce an enriched growth solution. In some aspects, the methods comprise irradiating the enriched growth solution to produce the gold nanoprisms. In some aspects, the disclosed nanoprisms the nanoprisms do comprise silver.

Provided are a method for recovering gold, in which gold is recovered from a solution containing a gold cyano complex using a crosslinked resin containing a vinyl amine unit, by which gold can be efficiently recovered from the solution not only in a case (A) where a concentration of the gold cyano complex in the solution is low but also in a case (B) where another metal is dissolved in the solution; a method for recovering gold, in which the crosslinked resin and the solution are brought into contact with each other to separate the crosslinked resin and the solution from each other, by which gold can be efficiently recovered from the solution not only in the case (A) but also in the case (B); and a gold recovery facility comprising: a container inside which the crosslinked resin is accommodated in a flowable manner; and a device which feeds the solution to the container, by which gold can be efficiently recovered from the solution not only in the case (A) but also in the case (B).

A process and system is provided for recovery of one or more metal values using solution extraction techniques and for metal value recovery. In an exemplary embodiment, the solution extraction system comprises a first solution extraction circuit and a second solution extraction circuit. A first metal-bearing solution is provided to the first and second circuit, and a second metal-bearing solution is provided to the first circuit. The first circuit produces a first rich electrolyte solution, which can be forwarded to primary metal value recovery, and a low-grade raffinate, which is forwarded to secondary metal value recovery. The second circuit produces a second rich electrolyte solution, which is also forwarded to primary metal value recovery. The first and second solution extraction circuits have independent organic phases and each circuit can operate independently of the other circuit.

Embodiments of the present invention are directed to novel methods for the solution-based production of silver nanowires by adaptation of the polyol process. Some embodiments of the present invention can be practiced at lower temperature and/or at higher concentration than previously described methods. In some embodiments reactants are added in solid form rather than in solution. In some embodiments, an acid compound is added to the reaction.

A method for synthesizing nanostructures includes introducing a solution of seed crystals into an initial growth solution to form a nanostructure synthesis mixture. The initial growth solution includes a precursor material and a reducing agent in a surfactant solution. Growth of nanostructures in the nanostructure synthesis mixture is monitored during a period of anisotropic growth of the nanostructures to determine a shift from stage II growth of the nanostructures to stage III growth of the nanostructures. The shift from stage II growth to stage III growth is identified, and after identifying the shift, a second growth solution is added to the nanostructure synthesis mixture coincident in time with the shift. The second growth solution includes the precursor material and the reducing agent in the surfactant solution.

Leaching aids, for example, when present in a leaching solution, and methods of using the leaching aids. The leaching aids can include one or a combination of compounds. The method of using the leaching aids can include a process of recovering metal from ore, for example, a process involving heap leaching, solvent extraction and electrowinning.

A method of recovering a metal from a low-grade ore which is subjected to cyanide leaching to produce a PLS which contains a metal cyanide which is removed from the PLS by ultrafiltration and nano-filtration, and then acidified and sulphidised to produce a metal sulphide from which the metal is extracted, and hydrogen cyanide which is recycled to the cyanide leaching step.

The present disclosure is directed to a gold recovery process in which activated carbon or another carbon-based material is used to accelerate thiosulfate leaching of gold from a gold-bearing material.

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) a leaching step comprising contacting the material with an acidic solution containing a lixiviant comprising an aqueous amino acid-thiourea compound formed from an amino acid (as herein defined) and thiourea (as herein defined), in order to form a leachate containing the precious metal and/or chalcophile metal; and (ii) a recovery step comprising recovering the precious metal and/or chalcophile metal from the leachate.

A method and a system for gold and silver recovery from a pregnant solution resulting from gold extraction from an ore using halogen, the method comprising lowering the oxidation reduction potential of the pregnant solution by mixing the pregnant solution with a reducer over the surface of a bed of silica, and flowing the mixture through the bed of silica. The system comprises a bed of silica, a feeder controlling feeding of the pregnant solution with a reducer to direct a mixture of an ORP less than 550 mV to the surface of the bed of silica, and a collector receiving a barren solution from the bed of silica after flowing of the mixture therethrough.