COMPOSITION NOT CONTAINING BORON FOR REMOVAL OF CRYOLITE-CONTAINING DEPOSITS Russian patent published in 2022 - IPC C23G1/02 C23G1/06 C23C22/73 C11D7/08 C11D7/26 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to an aqueous composition for removal of cryolite deposits from installations or parts of installations for conversion processing of metal surfaces, a concentrate for its production, and a method for removal of cryolite deposits from installations or parts of installations, serving for conversion processing of metal surfaces. The aqueous composition contains at least one mineral acid and at least one dicarboxylic acid of the formula HOOC-(CH₂)_х-COOH, where x is equal to 0-3, without addition of borate-containing compounds. Mineral acid has a normal total concentration in the range from 3.0 to 10 mol/l.

EFFECT: invention allows for provision of removal of cryolite deposits without the use of borate-containing compounds, wherein time necessary for full destruction/dispersion of cryolite deposits, as well as a number of dissolved cryolite deposits per unit of amount of a solvent are comparable with those, which are achieved by a combination of mineral acid and a borate-containing compound.

13 cl, 1 tbl