Rotary-Kiln Production of Coke from High-Ash Kazakhstan Coal for Use in Ferroalloy Production

Abstract

The composition and properties of high-ash (Ad = 38.7%) KZh coal from the Borly field (Kazakhstan) are determined. On the basis of industrial experiments regarding the coking of Borly coal in a rotary furnace, a production technology is developed for moderate-temperature high-ash coke. The characteristics of the coke produced are as follows: W r = 2.0%; Ad = 47.3%; V daf = 4.8%; Sd = 0.36%; and Pd = 0.022%. It also contains 58.3% SiO2, 28.4% Al2O3, and 3.3% Fe2O. Its properties are as follows: reactivity with CO2 at 1000°C $${{K}_{{{\text{C}}{{{\text{O}}}_{2}}}}}$$ = 2.7 cm3/(g s); electrical resistivity ρ > 1.9 × 106 Ω cm; porosity 29.8%; and structural strength Sst = 91.9%. High-ash coke may be used in the electrofurnace production of various ferroalloys.