Study on faster filtering residue out of acidolysis solution in preparation of feed-grade DCP by hydrochloric acid method

The cause of the difficulty in filtering out the residue in preparation of feed-grade DCP by hydrochloric acid method are studied through measuring particle size distribution and the composition and zeta potential of residue.Meanwhile,techniques for enhanced filtration are investigated.The results show:the faster filtration can be obtained by adding a small amount of H2SO4 to the hydrochloric acid;and the optimum proportion of H2SO4 is of 0.67%;adding proper amount filtrate to the acidolysis solution can reduce the concentration of the residue in the acidolysis solution and increase the flocculation effect and settling velocity of the residue.