| In the copper-molybdenum concentrate flotation separation, sodium cyanide is a widespread inhibitor, but sodium cyanide is the highly toxic substance, which is great harmful for health and environment, And dosage is large, which leading to the high costs of separation of copper and molybdenum, so the appropriate choice of non-toxic or low toxic inhibitor instead of sodium cyanide is of great significance. Sodium thioglycolate is promising in copper-molybdenum separation which can be used to inhibit the chalcopyrite, which is better than sodium cyanide and is the low toxic substances, so it can reduce the environmental pollution, Sodium thioglycolate is a very good selection to replace sodium cyanide to be as the chalcopyrite inhibitor. Therefore, research the technological synthesis of sodium mercaptoacetate in order to obtain high yield and stable quality product, and applied it to Cu-Mo flotation separation process to achieve non-cyanide flotation, which has good economic and environmental benefits.Thiourea as the raw material to synthesis thiourea sodium thioglycollate is low investment and easy to operate, the yield is also high for China's mining production, but production cost is high. The raw material price of sodium hydrosulfide is low and source is wide, which makes up the deficiency of thiourea method is a low-cost synthesis.Firstly, this topic researched the process of taking thiourea as raw materials to synthesis sodium thioglycolate, studyed the various factors and the ranges which affect the yield of the product, and used response surface method for the synthesis of process optimization experiments for the first time. At the basis of single factor experiment, through the RSM, the optimum theoretical conditions of synthesis sodium thioglycolate:pH of sodium chloroacetate is 6.50, Concentration of sodium hydroxide is 6.0 mol/L, Molar ratio between sodium chloroacetate and thiourea is 1:1.02, condensation reaction temperature is 80℃, condensation reaction time is 30min; Molar ratio between sodium chloroacetate and sodium hydroxide is 1:1.01, hydrolysis reaction temperature is 70℃, hydrolysis reaction time is 100min. the average yield is 85.43%. And then the magnified experiments study process has been done to provides a theoretical basis for the production and reliable parameters. Conducted a production test in zhongheng Energy Technology Company, Ltd. Shaanxi, the product quality is stabile and the yield is close to small scale and large-scale experiment. The product is used by separation process for copper-molybdenum ore, when the amount of sodium thioglycolate is 20-25g/t mine, the grade of molybdenum concentrate ore and copper content in final concentrate to reach the national standard GB3200-1989 requirements.In order to reduce raw material costs, this topic then studied at the condition of atmospheric pressure taking hydrosulfide sodium as materials to synthesis sodium thioglycolate kettle-style process. By controlling the synthesis process parameters, based on the single factor experiments, using response surface experimental design to gained the synthesis process of optimum conditions:molar ratio between sodium hydrosulfide and sodium chloroacetate is 1:1.6, reaction temperature is 40℃, reaction time is 15min. the average yield is 88.65%.Due to the kettle-type reactor shortcomings and its own characteristics of synthesis sodium thioglycolate response, the subjects tried to improve the synthesis reactor, carried out exploratory improval experiments using tubular reactor instead of the kettle reactor, which has achieved good results, some of product yield has improved significantly, but stability is not good. The process route has the value to further explore in the future, this explore experiment provides the ideas and scientific basis to in-depth study.
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