METHOD FOR PURIFYING ASH GRAPHITE Russian patent published in 2022 - IPC C01B32/215 

FIELD: chemical processes.

SUBSTANCE: invention relates to the technology for producing low-ash graphite usable as a construction material in nuclear power engineering, heat engineering, for manufacturing metal melting crucibles, for producing multicomponent glass, tubular heaters, and is also a raw material for producing colloidal graphite, graphite oxide, and expanded graphite. Method for purification of ash graphite includes the fluorination thereof by mixing with an aqueous solution of ammonium bifluoride. This is followed by the heat treatment of the reaction mixture at 150 to 160°C for 2.5 to 3.0 h with a mass ratio of graphite and ammonium bifluoride of 1:0.40 to 0.45. The fluorinated product cooled to room temperature is washed with water, mixed with an ammonium bisulphate solution, and subjected to heat treatment at 250 to 260°C for 2 to 3 hours. After cooling to room temperature, the product is pulped in water, filtered, washed with water directly on the filter, and dried at 60 to 70°C.

EFFECT: invention allows for an increase in the effectiveness of the method due to the simplification of the process flow, reduction in the duration of implementation, reduction in power consumption and consumption of ammonium bifluoride.

2 cl, 2 ex