Nitrophosphate fertilizer producing process eliminating calcium through direct freezing crystallization with low backpressure supersonic nozzle


Application Number: 00112697
Application Date: 2000.02.21
Publication Number: 1310153
Publication Date: 2001.08.29
Priority Information:
International: B01D9/04;C05B11/06;C05G1/00
Applicant(s) Name: Sichuan Univ.
Address:
Inventor(s) Name: Zhu Jiahua;Xia Sulan
Patent Agency Code: 00000
Patent Agent:
Abstract The main control feature of nitrophosphate fertilizer producing process is that by using supersonic steam injector and low pressure waste heat steam at about 120 deg.c and low backpressure, the nitric acid acidized liquid of phosphate ore is jet cooled to below 9 deg.c, so that calcium nitrate entraining acid insoluble matters are separated through stepped crystallization and filtering. The mother liquor is ammonia neutralized and added with proper potash before direct spray pelletizing to produce high-density ternary compound fertilizer. The separated calcium nitrate is dissolved to eliminate acid insoluble matter and made to absorb CO2 and ammonia to produce ammonium nitrate and calcium carbonate. The production process is short and low in cost.