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公开(公告)号：US20180155207A1
公开(公告)日：2018-06-07
申请号：US15568089
申请日：2016-04-22
申请人： OCP SA
发明人： Kamal Samrane , Abdelaali Kossir
摘要： The invention relates to a process for preparing synthetic calcium fluoride (CaF2) (min 90% CaF2 by weight) from fluosilicic acid, comprising the following steps: (a) reacting fluosilicic acid (H2SiF6) with ammonium hydroxide or ammonia in a first reactor so as to obtain a first slurry; filtering said first slurry so as to obtain a filtrate containing a solution of ammonium fluoride; (b) precipitating the solution of ammonium fluoride obtained as a filtrate in step (a) with calcium carbonate as a dry form or as a suspension at a concentration ranging from 10 to 80% by weight in a second reactor so as to produce a second slurry containing calcium fluoride and ammonium carbonate; filtering said second slurry so as to obtain a filter cake containing calcium fluoride and a filtrate containing a solution of ammonium carbonate; washing and drying said filter cake so as to obtain calcium fluoride and a filter cake washing containing a solution of ammonium carbonate; wherein a portion of the second slurry ranging from 10 to 70% is recycled to the second reactor (3) so as to enhance calcium fluoride crystallization; (c) evolving the major part of ammonia from the second reactor (3) in step (b) because of the partial decomposition of ammonium carbonate under reactor conditions and then scrubbing and returning said ammonia to the first reactor, and gathering and treating by distillation and condensation both ammonium carbonate solutions obtained as the filtrate and the filter cake washing in step (b) to recover liquid ammonia which is recycled to the first reactor (1).
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公开(公告)号：US20180222809A1
公开(公告)日：2018-08-09
申请号：US15750053
申请日：2016-08-03
申请人： OCP SA
发明人： Mehdi Khouloud , Abdelaali Kossir , Kamal Samrane
摘要： The invention relates to a method for manufacturing an ammonium phosphate fertilizer from a phosphoric acid aqueous solution that has less than 50% P2O5 concentration and is obtained by wet phosphate ore treatment, said phosphoric acid containing traces of cadmium, comprising the following steps: (a) neutralizing said phosphoric acid solution (1) with ammonia (3) up to a molar ratio N/P of between 0.1 and 0.8, (b) reacting said partially neutralized solution (4) with a sulfide source (6) so as to form a cadmium sulfide precipitate (9), (c) separating said precipitate (9) so as to obtain a refined ammoniated phosphoric acid solution (10), (d) ammoniating and granulating said refined solution (10) so as to form said fertilizer (12).
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公开(公告)号：US11873229B2
公开(公告)日：2024-01-16
申请号：US15568089
申请日：2016-04-22
申请人： OCP SA
发明人： Kamal Samrane , Abdelaali Kossir
CPC分类号： C01F11/22 , B01J10/00 , C01B33/186 , C01C1/026 , C01C1/26 , C01P2004/61 , C01P2006/12 , C01P2006/80
摘要： A process for preparing synthetic calcium fluoride (CaF2) (min 90% CaF2 by weight) from fluosilicic acid is provided. The processes comprises the steps of (a) reacting fluosilicic acid (H2SiF6) with ammonium hydroxide or ammonia in a first reactor so as to obtain a first slurry and filtering the first slurry so as to obtain a filtrate containing a solution of ammonium fluoride (b) precipitating the solution of ammonium fluoride with calcium in a second reactor so as to produce a second slurry containing calcium fluoride and (c) evolving the major part of ammonia from the second reactor and then scrubbing and returning said ammonia to the first reactor.
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公开(公告)号：US10947164B2
公开(公告)日：2021-03-16
申请号：US15750053
申请日：2016-08-03
申请人： OCP SA
发明人： Mehdi Khouloud , Abdelaali Kossir , Kamal Samrane
摘要： The invention relates to a method for manufacturing an ammonium phosphate fertilizer from a phosphoric acid aqueous solution that has less than 50% P2O5 concentration and is obtained by wet phosphate ore treatment, said phosphoric acid containing traces of cadmium, comprising the following steps: (a) neutralizing said phosphoric acid solution (1) with ammonia (3) up to a molar ratio N/P of between 0.1 and 0.8, (b) reacting said partially neutralized solution (4) with a sulfide source (6) so as to form a cadmium sulfide precipitate (9), (c) separating said precipitate (9) so as to obtain a refined ammoniated phosphoric acid solution (10), (d) ammoniating and granulating said refined solution (10) so as to form said fertilizer (12).
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