Invention Grant
US4377560A Process for producing low aluminum content phosphoric acid from high aluminum matrix 失效
从高铝基体生产低含铝磷酸的方法

Process for producing low aluminum content phosphoric acid from high
aluminum matrix
Abstract:
A process for producing low aluminum content phosphoric acid from high aluminum matrix comprises digesting the matrix in phosphoric acid; adding a flocculant to consolidate gelatinous or fine undigested solids; separating the flocculated solids from the mother liquid comprising monocalcium phosphate; acidifying the monocalcium phosphate with sulfuric acid to precipitate solid calcium sulfate and simultaneously adding at least one sodium or potassium compound or both to co-precipitate some of the soluble fluoride with the gypsum; separating the product phosphoric acid from the precipitated solids; recycling part of the lower fluoride content phosphoric acid back to the digestion step; and, aging the remainder of the product phosphoric acid until a precipitate of aluminum fluorophosphate forms and separating the precipitate to produce a low aluminum content phosphoric acid. Additional fluorine (e.g., a fluoride compound) can be added to accellerate formation of the aluminum fluorophosphate.
Public/Granted literature
Information query
Patent Agency Ranking
0/0