CHARGE FOR PRODUCTION OF PURE SILICON Russian patent published in 2008 - IPC C01B33/25 

FIELD: technological processes.

SUBSTANCE: for production of pure silicon in thermal-electric furnaces two-component formed charge is used. The first component of charge is briquettes made of quartz-containing raw materials with the main size of particles 10-90 mm, dynamic strength of not more than 7%, thermal strength of not more than 3%. Apparent density of briquette is 950 - 1,250 kg/m³. Briquette preserves its initial sizes during heating in furnace up to the temperature of liquidus of SiO₂ -1,720°C. The second component of charge is coal-containing briquettes with main size of particles of 10-70 mm, dynamical strength of not more than 9%, thermal strength of not more than 2%. Briquette preserves its initial sizes during heating in furnace up to temperature of beginning of main reaction of SiO₂ reduction. Suggested method makes it possible to create conditions for stationary heat and mass transfer at the border of top and reaction zones, provides growth of charge electrical resistance. At that furnace operates in the mode of "displacement reactor".

EFFECT: control of melting process and stability of mode parameters.

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