| 摘要 |
?The invention relates to the production of highly pure amorphous silicon dioxide. According to the invention, the method for producing high-purity amorphous micro silica and thermal energy from rice husk, said method comprising, in succession, washing the rice husk in acid, then with water, drying the rice husk and subjecting the latter to pyrolysis in a shortage of air at a temperature of 200 to 500°C, burning carbon residue from the pyrolysis at a temperature of 500 to 750°C and discharging the product, consists in that the carbon residue from the pyrolysis is burned in two stages - a preliminary burning stage in an inert medium until the residual carbon content in the ashes is a maximum of 10%, and then a stage of burning the residual carbon in a counterflow reactor in a flow of air, wherein, in the second stage, air is fed into the reactor in the discharging area while gaseous products from the combustion are removed from the charging area, enabling a temperature of 500 to 750°C to be maintained in the central area of the reactor. The result of the invention consists in producing amorphous silicon dioxide with a purity of up to 99.99% and a specific surface area of a minimum of 300 m2/g from rice husk in a continuous, pollution-free, energy-saving and ecologically clean process with simultaneous recycling of the gaseous products from the pyrolysis and products from incomplete combustion of the husk.
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