Title: Production of solid ammonium phosphate from low and medium grade phosphorus
Application Number: 85104948 Application Date: 1985.06.26
Publication Number: 1006922 Publication Date: 1987.01.14
Approval Pub. Date: Granted Pub. Date: 1988.05.25
International Classifi-cation: C05B7/00,C05B11/04,C05B11/10
Applicant(s) Name: Chengdu Univ. of Science and Technology Address:
Inventor(s) Name: Feng Yuqing, Wei Wenyan, Zhang Yunxiang
Attorney & Agent:
Abstract:
     Solid ammonium phosphate is produced by "concentrated acid slurry method" from low and medium grade phosphorus ore which contains about 10% of Fe-Al-Mg impurities. The process comprises: adding ammonia till an acidic ammonium phosphate slurry is obtained, in which the degree of neutralization is controlled to be 0.5-0.6, the best will be 0.52, concentrating the solution by multiple effect vacuum evaporation to obtain a solution of about 10% water content, granular product is made up in a rotary drum in which the second neutralization with ammonia, granulation and drying are accomplished at the same time. For obtaining product in powder form, the twice neutralized ammonium phosphate slurry is subjected to cold spraying. The degree of neutralization of slurry used in both granulation and atomization should be controlled to be 1.05-1.10. All multiple effect evaporators are anode protected.
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