The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample ...The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore： gold flotation-gold concen- trate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concen- trate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue--preferential flotation of lead and zinc and bulk flotation of lead and zinc--were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.展开更多
The Merrill-Crowe zinc-precipitation process has been applied worldwide on a large number of operations for recovering gold and silver from cyanide solutions. However, in some of the large plants this precipitate is o...The Merrill-Crowe zinc-precipitation process has been applied worldwide on a large number of operations for recovering gold and silver from cyanide solutions. However, in some of the large plants this precipitate is of low quality, because copper and especially lead are precipitated along with gold and silver resulting in a higher consumption of zinc powder, fluxes in the smelting of the precipitate, formation of mate and short life for crucibles. In this research, a method is proposed to recover lead, zinc and copper cyanide ions from barren solutions, from the Merrill-Crowe process with hydroxyapatite before the filter press. This technology is based on inducing nucleated precipitation of zinc, copper and silver ions in a serpentine reactor, using sodium sulfide as the precipitator and sulfuric acid for pH control. This procedure was successfully applied at WILLIAM Mining and BACIS Mining Group in México.展开更多
Recovery of gold and silver from a sulphide concentrate by thiourea leaching was investigat-ed.The effects of various parameters on the process,such as oxidants,the initial concentrationof thiourea and acidity in solu...Recovery of gold and silver from a sulphide concentrate by thiourea leaching was investigat-ed.The effects of various parameters on the process,such as oxidants,the initial concentrationof thiourea and acidity in solutions as well as reaction temperature,were systematically exam-ined.From the results it was confirmed that(a)oxidants had no significant influence on the dis-solution of gold and silver at a fixed initial concentration of thiourea;(b)the initial concentra-tion of thiourea and acidity affected the dissolution rate only in the earliest period of leaching;(c)the rate of the process was controlled by reagent diffusion.The optimum operations wereworked out for the thiourea leaching process of the concentrate.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51504031)
文摘The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore： gold flotation-gold concen- trate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concen- trate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue--preferential flotation of lead and zinc and bulk flotation of lead and zinc--were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.
文摘The Merrill-Crowe zinc-precipitation process has been applied worldwide on a large number of operations for recovering gold and silver from cyanide solutions. However, in some of the large plants this precipitate is of low quality, because copper and especially lead are precipitated along with gold and silver resulting in a higher consumption of zinc powder, fluxes in the smelting of the precipitate, formation of mate and short life for crucibles. In this research, a method is proposed to recover lead, zinc and copper cyanide ions from barren solutions, from the Merrill-Crowe process with hydroxyapatite before the filter press. This technology is based on inducing nucleated precipitation of zinc, copper and silver ions in a serpentine reactor, using sodium sulfide as the precipitator and sulfuric acid for pH control. This procedure was successfully applied at WILLIAM Mining and BACIS Mining Group in México.
文摘Recovery of gold and silver from a sulphide concentrate by thiourea leaching was investigat-ed.The effects of various parameters on the process,such as oxidants,the initial concentrationof thiourea and acidity in solutions as well as reaction temperature,were systematically exam-ined.From the results it was confirmed that(a)oxidants had no significant influence on the dis-solution of gold and silver at a fixed initial concentration of thiourea;(b)the initial concentra-tion of thiourea and acidity affected the dissolution rate only in the earliest period of leaching;(c)the rate of the process was controlled by reagent diffusion.The optimum operations wereworked out for the thiourea leaching process of the concentrate.
