LIME PRODUCTION PROCESS Russian patent published in 2003 - IPC

FIELD: inorganic substances technology. SUBSTANCE: invention relates to production of lime from carbonate material lumps in shaft furnaces and can be used in ferrous and nonferrous metallurgies, chemical industry, and construction. Process comprises: loading limestone lumps through loading device of furnace covering all cross-section area of furnace (more than 2 m in diameter); firing with fuel combustion products in countercurrent mode, while introducing peripherally gas fuel into furnace workspace; and discharging product. After loading of limestone is completed, solid fuel is additionally charged into axial space of furnace, which is inaccessible for penetration of gas fuel combustion products. Specific consumption of solid fuel in axial space of the furnace (K₀) is found from formula: K₀ = K_f(F_o/F_f), kg per 1 t lime, where K_f is specific consumption of solid fuel per total furnace cross-section area, which varies between 150 and 230 kg/t lime; F₀ is area of cross-section of axial space of furnace in firing zone, sq.m; and F_f is total furnace cross-section area, sq.m. Specific consumption of gas fuel is varied in proportion to K_o taking into account caloric values of solid and gas fuels, variation value V being calculated in terms of formula: V=K_o*A, cu.m/t lime, where A is ratio of caloric values of solid and gas fuels. EFFECT: increased productivity of process and increased quality of lime owing to uniform distribution of fuel combustion products and firing throughout all furnace cross-section. 2 cl, 2 tbl, 2 ex