Abstract: Disclosed is a process of leaching gold that can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, disclosed is a process of leaching gold from the mixture containing elemental sulfur and gold, the process involving combining the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

Abstract: Disclosed is a method of leaching copper and gold from sulfide ores, which includes Process (1) of bringing a first aqueous acidic solution which contains chlorine ion, copper ion and iron ion, but no bromine ion, into contact with sulfide ores under supply of an oxidizing agent, so as to leach copper component contained in the sulfide ores; Process (2) of separating, by solid-liquid separation, a leaching reaction liquid obtained in Process (1), into a leaching residue and a leachate; and Process (3) of bringing a second aqueous acidic solution which contains chlorine ion, bromine ion, copper ion and iron ion, into contact with the leaching residue obtained in Process (2) under supply of an oxidizing agent, so as to leach gold contained in the leaching residue.

Abstract: A process of leaching gold can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals are combined, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

Abstract: Disclosed is a method of recovering gold from an aqueous solution having a gold concentration of 10 mg/L or lower, using a plurality of extraction apparatuses for bringing the aqueous solution into contact with an extraction agent, arranged to configure a multi-stage extraction process, the method allowing the aqueous solution to continuously flow from the first-stage extraction process to the next-stage extraction process, while recycling the extraction medium used in each stage twice or more times for the extraction process of the same stage, without back extraction and reduction.

Abstract: Disclosed is a process of leaching gold that can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, disclosed is a process of leaching gold from the mixture containing elemental sulfur and gold, the process involving combining the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

Abstract: This invention provides a process of leaching gold that can be inexpensively and efficiently carried out without using cyan from the mixture containing sulfur and gold, typically from the material which contains sulfur and gold and is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, this invention provides a process of leaching gold from the mixture containing elemental sulfur and gold, comprising contacting said mixture and an aqueous solution of hydroxide of one or more of metals selected from the group consisting of alkali metals and alkaline earth metals, and reacting said hydroxides and elemental sulfur so that thiosulfate of corresponding metal, and thus, gold is leached by the thiosulfate produced.

Abstract: Disclosed is a method of recovering gold from an aqueous solution having a gold concentration of 10 mg/L or lower, using a plurality of extraction apparatuses for bringing the aqueous solution into contact with an extraction agent, arranged to configure a multi-stage extraction process, the method allowing the aqueous solution to continuously flow from the first-stage extraction process to the next-stage extraction process, while recycling the extraction medium used in each stage twice or more times for the extraction process of the same stage, without back extraction and reduction.

Abstract: Disclosed is a method of leaching copper and gold from sulfide ores, which includes Process (1) of bringing a first aqueous acidic solution which contains chlorine ion, copper ion and iron ion, but no bromine ion, into contact with sulfide ores under supply of an oxidizing agent, so as to leach copper component contained in the sulfide ores; Process (2) of separating, by solid-liquid separation, a leaching reaction liquid obtained in Process (1), into a leaching residue and a leachate; and Process (3) of bringing a second aqueous acidic solution which contains chlorine ion, bromine ion, copper ion and iron ion, into contact with the leaching residue obtained in Process (2) under supply of an oxidizing agent, so as to leach gold contained in the leaching residue.