METHOD OF SEPARATION OF CENOSPHERES OF FLY ASHES OF THERMAL POWER STATIONS Russian patent published in 2003 - IPC

FIELD: classification of powder materials; processing technogenious wastes, mainly fly ashes at thermal power stations for production of lighter components of ash-and-slag wastes (hollow aluminosilicate microspheres or cenospheres). SUBSTANCE: separation of cenospheres of fly ashes is performed by granulometric classification and gravitational separation in aqueous medium into products of various sizes and density. Granulometric classification is performed by screening in sieves and gravitational separation is performed in descending flow of aqueous medium at flow rate of 50-80 m/h, thus obtaining light product at bulk weight of 0.3-0.35 g/cu cm, heavy product at bulk weight of 0.35-0.45 g/cu cm and perforated cenospheres. Aerodynamic separation of product at bulk weight of 0.3-0.35 g/cu cm is performed additionally in ascending flow of air at flow rate of 0.1-0.4 m/s, thus obtaining light product at bulk weight of 0.1-0.3 g/cu cm and heavy product of bulk weight exceeding 0.3 g/cu cm. Dust and broken cenospheres are preliminarily separated from starting material by hydraulic separation of starting material, thus obtaining light and heavy products and removing heavy product. For separation of perforated cenospheres, degassing of light product of hydraulic separation is performed which is followed by filling the perforated cenopsheres with water and settling in form of heavy product. Perforated cenopsheres are subjected to gravitational separation; besides that, starting products or final products may be subjected to magnetic separation for obtaining products of preset content of magnetic component. EFFECT: increased degree of separation of cenospheres of fly ashes; reduced toxicity of process. 10 cl, 2 dwg, 2 tbl