POLYMETALLIC SLAG PROCESSING METHOD Russian patent published in 2022 - IPC C22B7/04 C01B33/00 

FIELD: chemical industry.

SUBSTANCE: invention relates to the processing of polymetallic slag and can be used to obtain desilicated polymetallic slag: raw materials for the production of iron, lead, zinc and compounds based on them, as well as silicon dioxide in the form of a commercial product. The processing method involves mixing slag crushed to a fraction of less than 0.1 mm with a solution of ammonium hydrodifluoride at a mass ratio of the concentrate to ammonium hydrodifluoride solution as 1: (5-20) at a temperature from 25°C to 90°C. The solid precipitate filtered from the obtained pulp is dried at a temperature of 60-80°C for 2-6 hours, then it is fired at 600-900°C for 1-4 hours to obtain desilicated polymetallic slag. The precipitate obtained after filtration of a suspension of hydrated silicon dioxide is calcined at a temperature of 500-800°C for 2-6 hours, while gases are captured with water during firing and calcination of these precipitates. The resulting solutions of ammonium fluoride are combined with a solution of ammonium fluoride obtained by filtration of a suspension of hydrated silicon dioxide, and then evaporated at a temperature of 130-170°C to obtain crystalline ammonium hydrodifluoride.

EFFECT: method provides chemical desilication of slag for its further processing.

1 cl, 3 ex