METHOD FOR AMMONIUM SULPHATE PREPARATION Russian patent published in 2009 - IPC C01C1/24 

FIELD: chemistry.

SUBSTANCE: invention refers to the technology of ammonium sulphate preparation from phosphogypsum and can be used in chemical industry at mineral fertilisers production. The claimed method for ammonium sulphate preparation includes: 1) phosphogypsum conversion in the reusable solution of ammonium sulphate with dispersed ammonia and carbon dioxide at constant stirring; 2) cooling of reaction pulp; 3) supporting in pulp liquid phase of the ammonia and ammonia carbonate overconcentration and following separation of the calcium carbonate; 3) phosphogypsum conversion is carried out in reusable solution of ammonium sulphate treated beforehand at continuous cooling with ammonia and carbon dioxide. If necessary ammonia and carbon dioxide overconcentration in the liquid phase of reaction pulp is corrected by feeding of dispersed reagent.

EFFECT: method allows to avoid the incrustation of heat-exchange surface with calcium carbonate, to increase the conversion degree and to increase the losses of ammonia and carbon dioxide from reaction pulp.

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