Filtration And Sedimentation Of MAP Suspension

Ammonium phosphate is one kind of important chemical fertilizer. If the hazardous impurity can be eliminated, we can get MAP of technical grade of high purity. The use of MAP of technical grade is very extensive: material for fire exting chemical , ammonium phosphate as fire exting chemical, additive in forage and so on. The extensive uses bring huge economic benefits for ammonium phosphate profession. So many industries spent many funds on study of purifying the MAP of agricultural grade . Because the properties of middle-quality phosphate ore in our country ,there are many impurities in production of MAP. Properties of these impurities are different, the crystals are small, these factors affect the properties of filtration and sedimentation of MAP suspension. So how to purity MAP is becoming key technology. The fertilizer MAP is get from Guizhou Hongfu Industry Corporation, The experiment of gravitational sedimentation, centrifugal sedimentation, microporous filtration at different conditions are carried out, and the the filtration characteristic has been comprehensively determined in the condition of deferent parameters. The experiment of gravitational sedimentation is carried out when density is 20%, temperature are 200C,400C,500C,600C,700C,800C,900C and 1000C. The result indicates that viscosity of MAP suspension will become lower as temperature becoming higher. However, at higher temperature , the move of grains becomes violent, which will effect gravitational sedimentation. For the fertilizer MAP in experiment, around temperature of 800C is ideal, adding chemical regents can strengthen sedimentation. The experiment of centrifugal sedimentation indicates that the impurities will become few at high temperature and high centrifugal force and long time for sedimentation. The experiment of microporous filtration is carried out at different temperature of suspention and different filtration pressure. The result shows that the rate of filtration will raise at high temperature, high pressure, large bore diameter. At the condition of experiment , bore diameter is chosen 1.2 μm . The result of this study has instructive meaning for improving the process of ammonium phosphate and select of equipment.