THEORY AND METHODS OF CREATING MACHINES FOR THE SYNTHESIS OF ENGINEERING MATERIALS
This article deals with methods of processing of the dust carried away from ore-thermal furnaces of silicon produc-tion. Chemical and granulometric analysis of dust entrainment of silicon production is carried out. The possibility of application of grav-ity-centrifugal separation to obtain target products, such as spherical silicon dioxide and nanostructured carbon, is considered. Separa-tion of dust from the silicon production bag filters in carbon and microsilica components took place on the developed stand that consist-ed of five consecutively mounted gravity-centrifugal dust collectors (cyclones). Microsilica particles, having a higher true density com-pared to carbon particles, were more exposed to the influence of centrifugal forces during the passage of the cyclone. The dust and gas flow was created with the help of a compressor and a dust-dosing device including a screw feeder and a slit gate. Dustiness of the dust and gas flow is 33 g/Nm3, with a performance of raw material of 1 kg/h. Dust from furnaces, collected by bag filters from the pipeline, carrying the dust and gas flow from the furnaces of silicon, was used as the raw materials. Simulation of the gravitational-centrifugal separation process showed the possibility of complete separation of silicon dioxide and carbon particles. As a result of a series of tests, it was possible to achieve an increase in the concentration of microsilica suspension from 93% to 98% with a product yield of up to 35% by weight. It was possible to increase the concentration of carbon fraction from 6% to 24% with a product yield of 10 %. Low efficiency of using this method of separation occurs due to mechanically bound particles of silicon dioxide and carbon, the separation of which is most likely possible only by chemical methods. Mathematical calculations and the results of mathematical modeling indicate that it is possible to increase the yield of the finished product in the case of changes in the geometric dimensions of dust-collecting devices and the modes of operation of the draft equipment of the stand.