| Because of the high recovery rate and strong adaptability,cyanidation is served as the most common method for extraction of gold.However,with the reduction of easily leached minerals the and people’s increasing awareness of environmental protection,the drawbacks of cyanidation become more and more obvious.Researchers are studying new reagent for gold extraction,in order to achieve better leaching effect.The leaching agent used in this paper is an organic chlorinated leaching agent(the patent reagent of research group),also known as 3YL.Studies have shown that 3YL leaching agent can not only make up for the shortcomings of cyanidation,but also can leach copper,lead and zinc elements simultaneously.However,we know little about the leaching principle of 3YL and its own properties,based on which the basic properties of 3YL,the kinetics of gold leaching and the application of 3YL in arsenic-containing gold ore are studied in this paper.The study of the basic properties of 3YL in this dissertation mainly includes the solubility and p H of 3YL,dissociation ability and oxidation ability of 3YL in solution under different environmental factors.The results show that:(1)The solubility of 3YL increases with temperature,and the aqueous solutions are weakly acidic.(2)When the acidity is 1 mol/L,the dissociation ability of 3YL is the highest.(3)When the acidity is 10-2mol/L,the 3YL solution has the strongest oxidizing property.The reaction of 3YL leaching gold is performed in three stages.In the initial reaction stage(0-25s),the process is controlled by chemical reactions.In the second reaction stage(25~300s),controlled by multi-factor mixing.In the third reaction phase(after 300s),the process is controlled by out-diffusion.Aiming at an arsenic-containing mine in Jilin Province,through the experiment of roasting — acid leaching — 3YL chloride leaching,this thesis studies the influenceof various parameters on the polymetallic leaching effect and determines the optimal conditions.The main conclusions are drawn as follows:(1)The leaching rate of gold and silver are mainly affected by the amount of calcium hydroxide and the acid leaching temperature in the process of roasting.(2)The leaching rate of copper is mainly affected by the amount of calcium hydroxide and the concentration of sulfuric acid.(3)The leaching rate of zinc is greatly affected by the solid-liquid ratio.(4)Although the leaching rate of plumbum is constrained by various factors,the overall impact is not very obvious,with good leaching effect.Considering the cost and the leaching effect,the best experimental conditions for the experiment were determined.For concentrates,the amount of calcium hydroxide is 2.43%;the acid leaching concentration of sulfuric acid is 8%;the acid leaching temperature is 80℃;and the leaching solid-liquid ratio is 1:4.For tailings,the amount of calcium hydroxide is6.71%;the acid leaching concentration of sulfuric acid is 8%;the acid leaching temperature is 80℃;and the leaching solid-liquid ratio is 1:4. |
PDF Full Text Request