METHOD FOR PROCESSING SODIUM-FLUORINE-CARBON-CONTAINING WASTE FROM ELECTROLYTIC ALUMINIUM PRODUCTION Russian patent published in 2024 - IPC C22B7/00 C01F11/22 

FIELD: waste treatment.

SUBSTANCE: invention relates to a method for processing sodium-fluorine-carbon-containing waste from electrolytic aluminium production to produce calcium fluoride and caustic soda solution. The method involves treating waste in a solution with a lime-containing reagent with stirring, with the weight ratio of the amount of fluorine in the waste to the amount of active calcium oxide in the lime-containing reagent being 1:(1.40 - 4.65), and maintaining a certain weight ratio of liquid to solid in the reaction mixtures. In this case, the weight ratio of liquid to solid at the start of interaction is set in accordance with a certain dependence. The total weight of the waste and the stoichiometric weight of calcium hydroxide, calculated from the fluorine content in the waste for the formation of CaF₂, are taken as solid in the reaction mixture.

EFFECT: reduced water consumption for preparing the reaction mixture, energy costs for heating and maintaining the temperature of the reaction mixture, stabilized concentration of caustic alkali in the solution obtained after treating waste with a lime-containing reagent, and also reduced duration of interaction of sodium-fluorine-containing waste components with a lime-containing chemical.

1 cl, 8 tbl, 4 ex