METHOD FOR COMPLEX PROCESSING OF ASH FROM BURNING COAL Russian patent published in 2017 - IPC B09B3/00 C01B33/12 

FIELD: technological processes.

SUBSTANCE: invention relates to complex processing of ashes from burning coals. Method involves blending the ash with sodium hydroxide, sintering at the temperature of 150–200 °C, leaching the sinter, separation of phases, desiliconization of the solution by adding sodium hydroalumosilicate into the solution. In compliance with this method prior to leaching the sinter it is washed with water to obtain a first silicate solution, the washed sinter is leached with sulphuric acid, the produced pulp is separated by filtration. Desiliconization of the solution is performed till complete extraction of silica to obtain a solution of aluminium sulphate and a silica-containing residue. Residue is dissolved in an alkaline solution to obtain a second silicate solution, which is combined with the first silicate solution directing further to produce white soot by carbonization. Technical result is reducing the sintering temperature and reducing consumption of reagents when reaching the alumina extraction at the level of 94.4–96.7 % and the silica extraction at the level of 93.9–98.2 %.

EFFECT: lower sintering temperature and reduced consumption of reagents.

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