| 摘要 |
Pure monocalcium phosphate-urea adduct of formula Ca(H2PO4)2. 4CO(NH2)2 and other high-purity prods., for use in fertilisers, detergents. food additives, yeasts, etc. are made without use of the thermal process of phosphoric acid prodn. or removal of impurities with selective solvents, by mixing single or triple superphosphate with eater and ppting. agents, e.g. H2SO4, NH3, H2S. The pptd. impurities are removed in a separator and an approx. wt. of urea is added to the mono-calcium phosphate soln. The solid phase separated, contg. gypsum phosphates, fluorine, calcium, iron, aluminium, silica, antimony, arsenic etc., can be recovered or converted to phosphoric acid. (Previously notified in week 8949)
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