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 reaction process for leaching gold from sulfide gold concentrates containing copperwith ammonia-ammonium thiosulfate solution containing copper（Ⅱ）can be divided into initialstage and later stage of reaction.Ini...The reaction process for leaching gold from sulfide gold concentrates containing copperwith ammonia-ammonium thiosulfate solution containing copper（Ⅱ）can be divided into initialstage and later stage of reaction.Initial stage of reaction is controlled by interface reaction.Lat-er stage of reaction is controlled by diffusion process of reaction through solid products layer.Whole leaching process is under the control of corrosion reaction of pyrite bearing gold.Actionof ammonium sulfate in the system is probably as follows:（1）NH<sub>4</sub><sup>+</sup> and NH<sub>3</sub> forms a buffer so-lution;（2）SO<sub>4</sub><sup>2-</sup>ion inhibites the oxidation and decomposition of S<sub>2</sub>O<sub>3</sub><sup>2-</sup>ion.Cu<sup>2+</sup>ion in thesystem acts as an oxidant and oxygen makes the Cu<sup>2-</sup>regenerate.展开更多
Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore...Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore from Yunnan Province, China, was investigated. The results show that free gold and auriferous sulfides account for 94.99 % of total gold. Without adding organic acid in floatation, only 82 % recovery of gold could be obtained.Gold recovery in Au/Pb concentrates increases by 9.29 %with oxalate added and by 7.35 % with citric acid added,respectively, while performances of lead and arsenic nearly keep a constant. A possible reason is that free gold is of wonderful selectivity against pyrite with organic activators.A new method to enhance gold recovery is proposed.展开更多
The effects of the concentrations of thiosulfate,copper and ammonia on the extraction of gold from sulfide gold concentrate have been studied.The results show that it is possible to reduce thiosulfate concentration.Mo...The effects of the concentrations of thiosulfate,copper and ammonia on the extraction of gold from sulfide gold concentrate have been studied.The results show that it is possible to reduce thiosulfate concentration.More than 95%of the gold could be extracted by a 0.2 mol/L thiosulfate leaching solution in two hours under suitable conditions.Therefore,the process of washing the residue was simplified,and the consumption and loss of thiosulfate carried by the washing residue were reduced.展开更多
The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550...The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550℃ as sodium chromate. The galena in lead sulfide concentrate is converted into lead carbonate in ammonium or sodium carbonate solution at 50-80℃ followed by the separation of lead carbonate formed from the unconverted sulfide ores by flotation. Gold associated with sulfide ore (such as pyrite and chalcopyrite) can be extracted into sodium thiosulfate solution without any pretreatment such as roasting, high pressure aqueous oxidation or bacteria pre-leaching.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.
基金Supported by the National Nature Science Foundation of China
文摘The reaction process for leaching gold from sulfide gold concentrates containing copperwith ammonia-ammonium thiosulfate solution containing copper（Ⅱ）can be divided into initialstage and later stage of reaction.Initial stage of reaction is controlled by interface reaction.Lat-er stage of reaction is controlled by diffusion process of reaction through solid products layer.Whole leaching process is under the control of corrosion reaction of pyrite bearing gold.Actionof ammonium sulfate in the system is probably as follows:（1）NH<sub>4</sub><sup>+</sup> and NH<sub>3</sub> forms a buffer so-lution;（2）SO<sub>4</sub><sup>2-</sup>ion inhibites the oxidation and decomposition of S<sub>2</sub>O<sub>3</sub><sup>2-</sup>ion.Cu<sup>2+</sup>ion in thesystem acts as an oxidant and oxygen makes the Cu<sup>2-</sup>regenerate.
基金financially supported by the National Natural Science Foundation of China(No.51374247)
文摘Free gold and gold wrapped in sulfides are considered as the object of gold floatation. However,floatation of free gold exhibits more variables in practice.In this study, improving gold recovery of a Pb-Zn sulfide ore from Yunnan Province, China, was investigated. The results show that free gold and auriferous sulfides account for 94.99 % of total gold. Without adding organic acid in floatation, only 82 % recovery of gold could be obtained.Gold recovery in Au/Pb concentrates increases by 9.29 %with oxalate added and by 7.35 % with citric acid added,respectively, while performances of lead and arsenic nearly keep a constant. A possible reason is that free gold is of wonderful selectivity against pyrite with organic activators.A new method to enhance gold recovery is proposed.
基金supported by China National Natural Science Foundation。
文摘The effects of the concentrations of thiosulfate,copper and ammonia on the extraction of gold from sulfide gold concentrate have been studied.The results show that it is possible to reduce thiosulfate concentration.More than 95%of the gold could be extracted by a 0.2 mol/L thiosulfate leaching solution in two hours under suitable conditions.Therefore,the process of washing the residue was simplified,and the consumption and loss of thiosulfate carried by the washing residue were reduced.
文摘The newly developed green leaching processes for chromium, lead and gold extraction from ores or concentrates are described. The chromium is extracted from the iron chromite ore with fused sodium hydroxide at 500-550℃ as sodium chromate. The galena in lead sulfide concentrate is converted into lead carbonate in ammonium or sodium carbonate solution at 50-80℃ followed by the separation of lead carbonate formed from the unconverted sulfide ores by flotation. Gold associated with sulfide ore (such as pyrite and chalcopyrite) can be extracted into sodium thiosulfate solution without any pretreatment such as roasting, high pressure aqueous oxidation or bacteria pre-leaching.
