METHOD FOR OBTAINING SILICON, ALUMINUM AND IRON OXIDES UNDER COMPLEX NON-WASTE PROCESSING FROM BOTTOM ASH MATERIALS Russian patent published in 2019 - IPC C22B7/00 C22B1/02 C22B3/04 C01B33/00 C01F7/00 

FIELD: technological processes.

SUBSTANCE: invention relates to a complex, non-waste technology for the production of silicas, aluminum and iron oxides from bottom ash waste (BAW). Method includes heating a mixture of BAW with ammonium fluoride, leaching with water at a temperature of 20–30 °C, filtration, treatment of the solution with ammonia water to form a precipitate of SiO₂. Next, leaching with water at a temperature of 20–30 °C the solid residue formed after the previous leaching with water, and treating the resulting solution with ammonia water to form a precipitate of Al(OH)₃ and Fe(OH)₃. Then, the treatment of the precipitate of Al(OH)₃ and Fe(OH)₃ solution of caustic alkali with the formation of a solution of aluminate and the preparation of a precipitate of Fe(OH)₃. Solution is then treated with an inorganic acid to form a precipitate of Al(OH)₃ and a solution of an inorganic salt.

EFFECT: technical result consists in the production of silicon, aluminum and iron oxides with a main substance content of not less than 98 %, the use of low temperatures, reducing the cost of equipment, the duration of the entire process and the cost of energy.

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