Study On Comprehensive Utilization Of Electric Dust And Ashes From Matte Making Smelting Colecting Gold

With the development of bath smelting technology,the technology of oxygen-enriched bottom converting matte and gold-catching process for treating refractory gold-copper ores has gradually matured In particular,the composition of the charging materials after the arsenic recovery by sudden cooling is more complex than that of the traditional copper smelting process,resulting in more complex composition of the electric dust and ashes produced in the smelting process.How to comprehensively recover the valuable elements from the ash by open-circuit treatment has become a new research topic.In this paper,the high-arsenic electric dust and ashes produced in the bottom blowing process of a smelting enterprise is taken as the research object,and the existing forms of copper,arsenic and zinc in the electric dust are clarified through the phase analysis:Copper mainly exists in the form of sulfide and copper sulfate The content of arsenic is mainly in the form of arsenate and arsenate oxide,which accounts for 99.20%of the total,and other forms only 0.80%.The content of zinc is mainly in the form of sulfate which is easy to Leach 78.20%,sulfide and oxide 21.80%.The experimental results show that the optimum conditions for the leaching of electric dust are as follows:controlling the concentration of sulfuric acid at the end of the reaction to be 30 g/L,leaching temperature to be 80℃,leaching time to be 2 H,and adding oxidant at the mass ratio of sodium chlorate to electric dust of 3:50.The leaching rate of copper by acid leaching from electric dust can reach 97.89%.The optimum conditions of arsenic removal from As3+-containing solution were determined by simulation experiments:pH<4,room temperature(no obvious effect of temperature),reaction time 55 min,initial concentration of As3+ 2 g/L,and the optimal S/As Molar Ratio 1.1:1.Under the same conditions,the optimal S/As mole ratio is 1.2:1,1.5:1 and 1.7:1.when the concentration of As3+is 4 g/L,6 g/L and 8 g/L,The optimal S/As molar ratio increases with the increase of the original concentration of arsenic.The removal rate of arsenic in the solution was 99%.The optimum conditions for Zn2+containing solution to be sulfided and dezincified were determined as follows:initial zinc ion concentration was less than 1 g/L,H2S with 30%concentration was introduced,pH value was controlled at 4,Reaction Time was 50 min at room temperature(temperature had no obvious effect).The recovery rate of zinc in solution can reach 99%.In this study,a new technical route for the treatment of electric dust is proposed,in which copper,arsenic and zinc are leached into solution by acid leaching,and lead,gold and silver are leached into slag and sent to lead smelting system for recovery.The copper ion is allowed to enter the extraction liquid,and then the extraction liquid is electrodeposited to recover copper.According to the different pH of sulfide precipitation,hydrogen sulfide was used to realize the step recovery of arsenic and zinc in solution and the comprehensive recovery of valuable metals in electric dust.