METHOD OF PREPARING THE COAGULATING AGENT BASED ON ALUMINIUM HYDROXYSALTS

摘要

FIELD: technology of inorganic substances. SUBSTANCE: interaction of aluminium sulfate in an aqueous solution with calcium- and chlorine-containing reagents is carried out at heating for two stages. At the first stage interaction of aluminium sulfate with calcium carbonate or hydroxide is carried out at 90-100 C for 1-3 h and the end product - aluminium hydroxysulfate is obtained; at the second stage process is carried out at the same temperature-time parameters. Formed aluminium hydroxysulfate is subjected for interaction with calcium chloride and aluminium hydroxychloride is obtained. Calcium sulfate precipitate formed at the first and the second stages is subjected for an aqueous-acid treatment for 0.5-1 h at mass ratio $$$ = (1.5-1): 1, at medium pH = 0.8-2.0. Washing water is used for at the second stage of process and at the stage of an aqueous-acid treatment of calcium sulfate precipitate. Reagents were added at amounts providing the preparing the end product at base 33-66.6 wt.-%. EFFECT: simplified method, decreased loss of coagulating agent, broadened technological possibilities. 5 cl