METHOD OF PRODUCING THE COAGULATING AGENT - ALUMINIUM HYDROXOSULFATE Russian patent published in 1997 - IPC

FIELD: technology of inorganic substances. SUBSTANCE: aluminium sulfate aqueous solution is treated with calcium hydroxide or carbonate at 90-100 C for 1-3 h. The parent reagents were dosed at amount providing the end product producing that exhibits basicity 33-66.6 wt.-%. Calcium hydroxide or carbonate is used as an aqueous suspension at mass ratio liquid : solid = 1.5: (2.75-1.0). Calcium sulfate deposit formed is subjected for an aqueous-acid treatment for 0.5-1 h at mass ratio liquid 1.5:(1.0-1.0), at medium pH = 0.8-2.0 and washing waters were obtained. The latter were fed to preparing the parent reagent and for an aqueous-acid treatment of calcium sulfate precipitate. Method is used for sewage and solutions treatment. EFFECT: improved method of agent making. 3 cl