METHOD OF CALCIUM SULPHATE PHOSPHOSEMIHYDRATE PROCESSING Russian patent published in 2010 - IPC C01F11/46 C04B11/00 C04B18/04 

FIELD: chemistry.

SUBSTANCE: invention relates to recycling of wastes of extraction phosphoric acid production - calcium sulphate phosphosemihydrate. Method of recycling calcium sulphate phosphosemihydrate - wastes of extraction phosphoric acid production into calcium sulphate dehydrate, including mixing phosphosemihydrate with lime component and further compaction of obtained mixture, lies in the following: calcium sulphate phosphosemihydrate, obtained in production of extraction phosphoric acid by means of single-stage semihydrate method, is mixed in mixer with dry lime, which is supplied in amount 10-30 kg in terms of CaO per 1 t of phosphosemihydrate, mixing is carried out until mixture pH equal to 11-12 is reached, compaction is carried out layer-by-layer, value of each layer constituting 30-50 cm, calcium sulphate dihydrate being obtained in form of strong monolithic mass.

EFFECT: method allows to recycle calcium sulphate phosphosemihydrate, obtained as wastes of extraction phosphoric acid production, into calcium sulphate dehydrate, which can be used as cement setting regulator.

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