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.

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.

The main steps are as follows: purification, de-leading, recovery and filtration, dissolving lead, hot filtration, cooling filtration, washing and hot decomposition, silver is recycled as silver powder, lead was recovered in the form of red lead, yellow lead and chlorinated lead respectively. Compared to existing technologies, the invention adopts a wet process, the amount of waste gas and dust produced in the process of fire treatment is reduced; silver powder, red (yellow) lead and chloride lead were obtained, it can be sold as final product with high value-added features. The tail liquid produced by the process returns to the corresponding process respectively, and the tailless liquid is discharged. The pyrolysis flue gas returns to the lead removal process, flue gas treatment process is reduced, lead smoke pollution is avoided. This method has the characteristics of simple technics and pollution-free process.

THIS invention relates to a process for the enhanced recovery of chromite and platinum group metals (PGMs) from a mixed chromite/PGM ore. Ore is ground 12, classified 14, to produce a coarse fraction and a fine fraction 36. The coarse fraction is subjected to gravity separation 16 and coarse particle flotation 20 to obtain a chrome concentrate and a PGM concentrate. The fine fraction 36 and PGM concentrate are ground 28, and subjected to conventional flotation 30 to obtain a PGM concentrate product 32. The benefits of this novel configuration of gravity concentration and coarse flotation technologies, as applied to both chromite and PGM recovery, are higher recoveries of chromite in a saleable concentrate, higher recoveries of PGMs and base metals, and lower chromite content in the PGM concentrate.

THIS invention relates to a process for the enhanced recovery of chromite and platinum group metals (PGMs) from a mixed chromite/PGM ore. Ore is ground 12, classified 14, to produce a coarse fraction and a fine fraction 36. The coarse fraction is subjected to gravity separation 16 and coarse particle flotation 20 to obtain a chrome concentrate and a PGM concentrate. The fine fraction 36 and PGM concentrate are ground 28, and subjected to conventional flotation 30 to obtain a PGM concentrate product 32. The benefits of this novel configuration of gravity concentration and coarse flotation technologies, as applied to both chromite and PGM recovery, are higher recoveries of chromite in a saleable concentrate, higher recoveries of PGMs and base metals, and lower chromite content in the PGM concentrate.

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).

Conjugated organic polymers doped with anions and methods for the use of the anion-doped conjugated organic polymers in the selective electroless extraction and recovery of gold or silver from samples containing gold anions or silver anions are provided. The anion-doped polymers have a conjugated, positively charged backbone chain that is charge-balanced with associated dopant anions.

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 during the 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 comprise silver.

Provided is a monatomic amorphous palladium, a method for preparing the same and use thereof. The method comprises a) loading a monatomic palladium powder on a silicon nitride substrate; b) heating the silicon nitride substrate loaded with the monatomic palladium powder obtained in a) up to a temperature of 800° C. to 1000° C. and keeping the temperature for at least 3 minutes; and c) cooling a system of palladium and silicon nitride obtained in b) to room temperature at an apparent cooling rate greater than 10.sup.3° C./second, thus obtaining the monatomic amorphous palladium.

Provided is a monatomic amorphous palladium, a method for preparing the same and use thereof. The method comprises a) loading a monatomic palladium powder on a silicon nitride substrate; b) heating the silicon nitride substrate loaded with the monatomic palladium powder obtained in a) up to a temperature of 800° C. to 1000° C. and keeping the temperature for at least 3 minutes; and c) cooling a system of palladium and silicon nitride obtained in b) to room temperature at an apparent cooling rate greater than 10.sup.3° C./second, thus obtaining the monatomic amorphous palladium.