FIELD: chemistry.
SUBSTANCE: invention relates to a method of producing carbon black by thermal decomposition of rubber crumbs of used car tyres using carbon dioxide and can be used in industry, agriculture and other industries, where actions are carried out for thermal decomposition of rubber crumb obtained from used car tyres. Method of producing technical carbon by thermal decomposition of rubber crumbs of used car tyres using carbon dioxide gas includes preheating rubber crumbs with moisture content of 9–12% and size of its fragments 1–6 mm to 310–340 °C, drying to moisture content of 0.9–1.1% and subsequent mechanical destruction of rubber crumb into smaller fragments using centrifugal force and impact load by the rubber crumbs collision against the thermal decomposition chamber concave steel wall with temperature of 800–810 °C, removal of thermal decomposition products outside the thermal decomposition chamber, the use of a dosing hopper, a screw conveyor, a centrifugal-impact mill, communication of the output of the dosing hopper to the input of the screw conveyor, communication of the output of the screw conveyor to the input of the centrifugal-impact mill containing an electric motor, horizontal scattering disc with an end surface, an upper surface and a lower surface, a thermal destruction chamber with a cavity and an annular groove with an upper region and a lower region, the electric motor communication with the horizontal scattering disc, horizontal scattering disc arrangement relative to the annular groove with possibility of rubber crumbs supply into the thermal destruction chamber cavity from the horizontal scattering disc upper surface side and the annular groove upper area, as well as with possibility of thermal decomposition products removal from the thermal destruction chamber cavity on the side of the horizontal scattering disc lower surface and the annular groove lower region. In this case, before the rubber crumb supply to the thermal decomposition chamber cavity, the kinetic energy of each individual rubber crumb is increased by increasing its weight due to the ambient air displacement from the pores, cracks and their filling with carbon dioxide, the density of which is higher than the ambient air density, wherein said displacement and filling is carried out for 1 minute with simultaneous agitation of rubber crumbs at excess pressure of carbon dioxide gas 200–300 Pa, and the centrifugal force is formed by means of an electric motor with power of 11 kW, which rotates a horizontal scattering disc with diameter of 610 mm with rubber crumbs at speed of 3000 per minute, wherein rubber crumbs, before collision with thermal decomposition chamber concave steel wall, displaced in the cavity of the thermal decomposition chamber to distance of 270–mm, which is preliminarily formed between the end surface of the horizontal scattering disc and the opposite surface of the concave steel wall of the thermal decomposition chamber, solid fraction as technical carbon is produced directly at thermal decomposition chamber outlet.
EFFECT: development of a new method for producing technical carbon as a finished product using carbon dioxide, thermal decomposition of rubber crumbs of used car tyres with capacity of 2000 kg/h, directly at the outlet of the thermal decomposition chamber of the centrifugal-impact mill, the physical and chemical properties of which correspond to technical carbon of T-900 according to GOST 7885-86 “Technical carbon for the production of rubber. Technical specifications”.
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