METHOD FOR COMPLEX PROCESSING OF ASH-SLAG WASTES (VERSIONS) Russian patent published in 2016 - IPC B03B9/04 

FIELD: technological processes.

SUBSTANCE: invention relates to processing of ash-slag wastes from burning coal and can be applied to complex extraction of commercial products in form of finished concentrates both directly at thermal power plants and at sludge fields of TPP. Method for complex processing of ash-slag wastes from thermal power plants operating on coal fuel includes system of ash-slag waste transportation, waste preparation facility with removal of under-burning and serial raw of conversion process stages, in order to selectively extract iron-containing and aluminosilicate concentrates, as well as precious metals. Ash-slag wastes with particle size of not more than 0.5 mm after removal of under-burning and sludge are delivered to magnetic separation. Removal under-burning is carried out as fraction +0.5 mm during classification on screen. Magnetic separation is carried out in two stages: first stage is carried out in weaker, compared to second stage, magnetic field, and low-magnetic fraction after first stage of magnetic separation is processed under stronger magnetic field. According to first version, combined magnetic fractions of both stages of magnetic separation are sent to first screw separation in order to increase quality of iron-containing concentrate, and tails of second step of magnetic separation are sent to second screw separation for producing aluminosilicate concentrate. Heavy fraction of second screw separation is delivered to concentration table for extraction of precious metals. According to second version, magnetic fraction of both stages of magnetic separation are combined to obtain iron-containing concentrate, and aluminosilicate concentrate is obtained in form of tails after second stage of magnetic separation. At first stage of magnetic separation, magnetic field intensity is maintained not more than 100 kA/m. At second stage of magnetic separation, magnetic field intensity is maintained not less than 600 kA/m.

EFFECT: higher efficiency of extraction of finished products from ash-slag wastes.

15 cl, 2 dwg, 3 tbl