Research On Reclaiming Arsenic And Sulphur From Biological Oxidation Gold Extraction Waste Water

In recent years, bio-oxidation of gold extraction technology has become one of the main process in the gold industry.But this process will generate a lot of acidic waste water, make tremendous pressure on the environment.Present processing of the arsenic waste water methods are not only consume the massive manpower, the physical resource and the financial resource, takes the massive farming, also has the hidden trouble to the ecological environment;meanwhile, the arsenic, iron, sulfur and other valuable elements in the acidic waste liquid are wasted. This paper researches acidity arsenic metallurgy waste water of the valuable element recycling, effective use of resources, having the important theory and the practical significance.The main research contents and conclusions are as follows:(1)This thesis studies about the enrichment solution including arsenic which seperated from metallurgical waste of arsenic acid and add in copper sulfate to make copper arsenate. This thesis mainly investigate the effect of pH value, intensity of stirring and temperament on the recycle rate of arsenic;based on single factor experiments,the three factors and three level orthogonal experimental parameters were optimized to determine the optimum conditions for recovery of arsenic,that is: pH=5.5,T=50℃,stirring intensity is500rpm; arsenic recovery rate reached94.66%.(2)Study on reactive kinetics of preparing copper arsenate,the activdation energy is Ea=5.12kJ/mol Pre-exponential parameter is A=0.288In the process of recovering arsenate,the relationship of the reaction rate and the arsenate concentration is dmD/dt=kB/cB1.09kB/8=0.288e-5.12/RT(3)In the experiment, after the precipitation of copper arsenate, we can get lots of sulfide in the filtrate seperated from solid and liquid, and then we add milk of lime to make calcium sulfate. This experiment explores the effect of such factors as the intensity of stirring, temperature and the amount of milk of lime on the recycle rate of sulfur.Determine the optimum conditions for recovery of sulfur,that is:stirring intensity is:600rpm,T=70℃,the ratio of solid and liquid is1.5:1; sulfur recovery rate reached95.65%.(4)The calcium sulfate which obtained by recovering sulfur as the research object,study the preparation of calcium sulfate whisker.This thesis mainly investigate the effect of temperament, pH value,WCasSO4(concentration of calcium sulfate) and reaction time on the average aspect ratio of whisker;based on single factor experiments,the four factors and three level orthogonal experimental parameters were optimized to determine the optimum conditions for preparation of calcium sulfate whisker,that is:T=130℃,pH=3,concentration of calcium sulfate is5%,reaction time is2.5hours; the average aspect ratio of whisker reached87.