| HPF desulfurization technology have been widely used in the steel factory and coking plant for processes of desulfurization and decyanogen, due to its high desulfurization efficiency, less land occupation, simple operation process and low cost. However, producing a certain amount of the desulfurization waste materials by using HPF desulfurization technology, recycle utilization of these waste materials were widely concerned.Based on the common desulfurization methods and desulfurization wastewater treatment methods, mainly introduces the process of HPF extraction ammonium thiocyanate and ammonium thiosulfate salt in desulfurization waste materials by fractional crystallization methods, and the influencing factors on the yield and purity of product were analyzed, improving purity and yield of the corresponding product by controlling and adjusting these factors.In this thesis, the main related influencing factors is studied by using single factor variable method. Based on some experimental results and relevant information, it is found that the some main influence factors(the crystallization temperature, stirring speed, type and content of impurities in the solution, supersaturation, density and viscosity of solution, crystallization kettle structure, crystal system) affected purity and yield of ammonium thiosulfate and ammonium thiocyanate salt. Due to the limitation of experimental conditions and operating cycle, several factors are studied. The influence of temperature, stirring speed and impurity content on the product were studied. After repeated experiments, the experiment results indicated that the best amount of impurities in the range of 15~20 NTU, the best temperature of crystallization of ammonium thiosulfate in the temperature range of 45 to 50 oC, and it is appropriated to stirring speed should be controlled in the range of 300 ~ 400 r/min. So the purity, yield and crystallization rate of product become higher in some extent, then improve the production capacity of product. |
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