C - Chemistry – Metallurgy – 01 – F
Patent
C - Chemistry, Metallurgy
01
F
C01F 11/18 (2006.01)
Patent
CA 2214132
A method for producing precipitated calcium carbonate by reacting an aqueous solution of calcium nitrate [Ca(NO3)2] with an aqueous solution of ammonium carbonate [(NH4)2CO3] and allowing calcium carbonate to precipitate from the resultant mixture containing nitrate [NH4NO3] in the mother liquor, the process being characterised in that: (i) the calcium nitrate [Ca(NO3)2)] solution utilised in the processes is prepared by slaking lime [CaO] in water in the presence of ammonium nitrate [NH4NO3] to form calcium nitrate [Ca(NO3)2] and ammonium hydroxide [NH4OH] in solution, filtering the solution to render it solids free, and heating the filtrate to dissociate the ammonium hydroxide [NH4OH] and to drive ammonia gas [NH3] from the solution; (ii) the ammonium carbonate (NH4)2CO3 solution utilised is prepared by absorbing ammonia gas [NH3] and carbon dioxide gas [CO2] in water, the ammonia gas preferably being derived from the step in (i) above in which the Ca(NO3)2 solution is heated; and (iii) the ammonium nitrate used is derived from the precipitation phase during which calcium carbonate is precipitated from the mother liquor containing ammonium nitrate.
Procédé de production de carbonate de calcium précipité, consistant à faire réagir une solution aqueuse de nitrate de calcium [Ca(NO¿3?)¿2?] avec une solution aqueuse de carbonate d'ammonium [(NH¿4?)¿2?CO¿3?], et à permettre au carbonate de calcium de précipiter à partir du mélange obtenu renfermant un nitrate [NH¿4?NO¿3?] dans la liqueur mère. Ce procédé est caractérisé en ce que (i) pour préparer la solution de nitrate de calcium [Ca(NO¿3?)¿2?] utilisée dans les procédés, on éteint de la chaux (CaO) dans de l'eau en présence de nitrate d'ammonium [NH¿4?NO¿3?] pour former le nitrate de calcium (Ca(NO¿3?)¿2?) et de l'hydroxyde d'ammonium [NH¿4?OH] en solution, on filtre la solution pour en éliminer les matières solides, et on chauffe le filtrat afin de provoquer la dissociation de l'hydroxyde d'ammonium [NH¿4?OH] et de débarrasser la solution de gaz ammoniac [NH¿3?]; (ii) pour préparer la solution de carbonate d'ammonium (NH¿4?)¿2?CO¿3? utilisée, on procède à l'absorption dans l'eau du gaz ammoniac [NH¿3?] et du gaz carbonique [CO¿2?], le gaz ammoniac étant de préférence dérivé de l'étape (i) ci-dessus, dans laquelle on chauffe la solution de Ca(NO¿3?)¿2?; et (iii) on dérive le nitrate d'ammonium utilisé de la phase de précipitation au cours de laquelle on précipite le carbonate de calcium à partir de la liqueur mère renfermant du nitrate d'ammonium.
Gomersall John Edward
Gowling Lafleur Henderson Llp
Pretoria Portland Cement Company Limited
LandOfFree
Calcium carbonate precipitation method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Calcium carbonate precipitation method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Calcium carbonate precipitation method will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1355697