METHOD FOR PRODUCING IRON SULFATE FROM SLUDGE FROM TREATMENT OF CHROMIUM-CONTAINING WASTEWATER Russian patent published in 2024 - IPC C01G49/14 C02F11/14 C02F103/16 C02F101/22 

FIELD: processing of iron-containing waste from the chemical industry.

SUBSTANCE: invention is related in particular to a method for producing iron sulphate from sludge from treatment of chromium-containing wastewater. The starting material containing an iron (III) compound is dissolved in excess sulfuric acid, metallic iron is added to the resulting solution, after which the solution is filtered and cooled until iron sulphate crystals precipitate. The feedstock is sludge from the reagent treatment of chromium-containing wastewater, which includes a chromium (III) compound, a calcium (II) compound, iron (III) hydroxide as an iron compound and is in a finely dispersed state. The released iron sulphate crystals are separated by centrifugation, while the mother solution obtained by centrifuging the solution is evaporated and cooled until the second portion of iron sulphate crystals precipitates.

EFFECT: proposed method allows to expand the raw material base for obtaining iron sulfate.

4 cl, 2 ex