Comprehensive Assessment Of Disposal Program For Phosphogypsum

With the continued development of China’s phosphate fertilizer industry, phosphogypsum emissions had an increasing trend year by year, and the main stockpiling approach not only occupy a lot of land, also have polluted the regional environment seriously, and have potential hazards on the surrounding residents, how to properly handle the phosphogypsum has become an important problem needed to solve. Experimental studies and engineering practice shows that phosphogypsum is a recyclable resource, there are variety approaches to deal with phosphogypsum currently, such as the production of gypsum blocks, cement retarder, soil conditioners, etc., but the characteristics of phosphogypsum is different, also the environment, so its appropriate treatment programs also vary, so how to choose phosphogypsum treatment program scientific and effectively have a great significance for the promotion of the utilization of phosphogypsum and promote the development of resource-conserving society.To solve this problem, the paper summarized phosphogypsum pollution characteristics and treatment used commonly under the premise, determined the weight of phosphogypsum treatment program evaluation indexes based on improved analytic hierarchy process, combined the fuzzy comprehensive evaluation method, constructed an index system about comprehensive evaluation of phosphogypsum treatment options, evaluated the treatment effect by different treatment programs for three phosphogypsum yard respectively, and obtained the optimal treatment program.The results show that environmental benefits is the maximum weight and the social benefits is the minimum weight in guidelines layer by improved analytic hierarchy process,the values is 0.3892 and 0.1351, respectively; secondary pollution control, phosphogypsum utilization, the amount of secondary solid waste and product benefits in index layer have the greater comprehensive weight, the value is 0.1577,0.1103,0.1213 and 0.1124 respectively; the comprehensive weight of increase employment opportunities and social recognition of the right is lower, the value is 0.0384 and 0.0461 respectively. The comprehensive Evaluation Index System that paper constructed containing the target layer, criterion layer and index layer of the three levels for a total 12 indicators, the score points were 6.41691,7.6700,7.0355 when sulfuric acid and cement, gypsum powder and gypsum block system applied to storage yard one, so producing gypsum powder and gypsum block is the most appropriate treatment options for the storage yard one; the score points were 6.0089, 6.7297,7.1223 when 3 systems applied to storage yard two; the score points were 5.4842,5.9985,7.1353 when 3 systems applied to storage yard three, so the production of cement retarder is most appropriate treatment options for the yard two and three.