METHOD OF EXTRACTING UNBURNED CARBON FROM TPP FLY ASH Russian patent published in 2019 - IPC B03B9/04 B03D1/02 B09B3/00 

FIELD: waste processing and disposal.

SUBSTANCE: invention relates to processing of wastes from thermal power plants, in particular to a method of recovering unburned carbon from thermal power plant fly ash to obtain an aluminosilicate product. Method of recovering unburned carbon from thermal power plant fly ash involves formation of an aqueous suspension of fly ash, adding to the collector and foaming agent suspension, mixing the suspension with reagents and hydrophobization of unburned carbon to form a foam layer in order to lift unburned carbon. In an aqueous suspension of fly ash at ratio of ash: water 1:2–1:4, a collector is added in the form of a mixture of thermal cracking gas oil with kerosene, preferably in ratio of 1:1 in amount of 5–8 kg per ton of ash. Suspension and header are mixed for 1–5 minutes. Afterwards foaming agent is added to obtained mixture in form of pine oil in amount of 0.2–0.3 kg per ton of ash, mixed for 0.5–1 minutes, after which mixture of suspension with reagents is flotated for 5–10 minutes to form foam layer and tailings of main flotation with subsequent extraction and obtaining of target products in form of carbon, suitable for combustion at TPP, and aluminosilicate product for use in production of construction materials. Foam product of the main flotation is subjected to operation of cleaning flotation in the second flotation cell to produce a second concentrate of foam product and chamber industrial product.

EFFECT: considerable reduction of consumption of expensive reagents used during implementation of the method and simplification of process equipment of flotation process for obtaining of target products in form of higher-quality carbon concentrate and aluminosilicate product under condition of complete use of flue ash of TPP.

1 cl, 4 ex