| Copper-bearing gold ore was recognized as a kind of refractory ore, also is an important gold resources of china. At present, more than 80% of gold mine in the world extract gold from ore by cyanide process, but cyanide soluble copper in the copper-bearing gold ore will make gold surface passivation, compete cyanide and oxygen consumption with gold, copper ion accumulating with the cyanide barren liquor circulating, which serious impact on gold production, reducing the gold recovery rate, increasing the consumption of cyanide.At present, the traditional cyanide leaching-activated carbon adsorption process encounter great technical problems in the processing of low grade copper-bearing gold ore, but the research is still in its infancy, there is no successful precedent for industrial application.Basing on the previous studies, this paper study on low grade copper-bearing gold ore of Zijinshan Gold Copper Mine, analyze detailedly the behavior of copper in gold leaching and adsorption process and the effect on leaching of gold, carry out a system experiment on the influence factors of the activated carbon adsorption of copper and gold-copper separation of cyanide leaching solution.Research results show that, the leaching velocity and leaching rate of gold and copper variation with time is almost synchronous in cyanide leaching of copper bearing gold ores, so increasing the initial cyanide concentration in leaching, as to improve the leaching rate of gold, but at the same time, the leaching rate of copper increases; By controlling the active carbon adsorption working solution pH≥10,free cyanide concentration≥100mg/L,which can realize gold selective adsorption by activated carbon economy in the total Cu of rich liquid within 200mg/1, gold adsorption rate is greater than 90%, copper adsorption rate is less than 5%,so as to control the influence of copper on gold adsorption;Rich liquid of gold cyanide leaching sulphidization-acidification process realize the rich liquid selective removal of copper and cyanide recovery, solve the problem that the cumulation of copper ion effect gold recovery and cyanide consumption problem carry with adsorption lean liquid circulation,the copper recovery rate of expand test is 91.43%, and the cyanide recovery rate is 94.06%.Basing on the research that how to realize the organic combination of the sulphidization-acidification process and conventional cyanidation-activated carbon adsorption process with industrial applications, this paper recommended a comprehensive system treating process of the copper bearing gold ore, that leaching of gold in most suitable concentration of sodium cyanide,the copper rich solution of gold leaching selectivly remove and recover copper by sulphidization-acidification process, coordinating with the process that activated carbon selective adsorption and recovery of gold by multi parameter control,such as adsorptive rich liquid pH, concentration of copper, cyanide concentration. And has preliminary designed the sulphidization-acidification process, the economic benefits were demonstrated, results showed that to construction a 2500m3/d industrial scale system, investment is about 1500000 yuan, operating costs 6.442 yuan /m3, the direct economic benefits is about 6000000 yuan every year, has good economic benefit.This paper solves a series of technical and economic problems that copper hinder gold extraction from low grade copper-bearing gold ore by conventional cyanide leaching-activated carbon adsorption process. Achievements of research not only help the comprehensive utilization of low grade copper-bearing gold resources of Zijinshan Gold Copper Mine, also have important reference value to the comprehensive recovery of similar copper gold ore and utilization of secondary resources at home and abroad. |
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