The Recycling Of AK Sugar Production By Pretreatment Of Gypsum Waste

AK sugar gypsum plaster is generated in the process of recycleing triethylamine with Phosphogypsum and gypsum plaster are the chemistry gypsum, which studies have shown that its main components are calcium sulfate dihydrate.It is a material with excellent performance.Chemical gypsum's properties close to the natural gypsum plaster which can be used instead of natural gypsum in building materials.Inevitably the waste gypsum will contain some raw materials or intermediate products,and it will affect the gypsum recycling. In order to make better use of AK sugar gypsum, this paper studies the determination of organic impurities and removal methods, also studied to obtain the best gypsum calcining temperature and holding time.In order to better describe the sugar content of organic matter in plaster,first studied the cast method of organic carbon. Reference Method for determination of soil organic matter,The subject compared the titration of ferrous sulfate, calcined method and spectrophotometry, while By spike recovery, decided tha ferrous sulfate titration method is for determing AK sugar gypsum's organic carbon content, standard addition recovery of 90% or more, the experimental data are reliable.In order to reduce organic carbon of the sugar gypsum,by comparing the pretreatment methods of removing organic in the AK sugar gypsum, the results show that,although surfactants can promote the dispersion and solubilization of pollutants, but because of its in the washing process, and can not be all removed, affecting the determination of organic carbon, could not explain the effect of organic matter removal. As pH has the dissolution of organic matter ,and the gypaum display weak base,the experiments show that the pH of 5-6 weak acid solution have best washing result, three times the amount of water washed organic carbon fractional removal rate of 73% After more than four times has reached 90%.Waste gypsum is mainly calcium sulfate dihydrate, when it first become gypsumβ-CaS04-1/2H20) that can be used. The subject of the calcined gypsum to obtain the temperature, holding time and the aging time by experimental comparison to determine the calcination temperature of 170-180℃constant temperature 2 hours and get half the water content of gypsum, while the aging time of the week is appropriate.