Replacing Coke with Noncaking Coal in the Production of Manganese Ferroalloys

The use of D and B coal as reducing agents in the production of manganese ferroalloys is considered. Such coal is preferable to coke on account of its composition ( A d = 5.8% and 8.5% for D and B coal, respectively; P d = 0.029 and 0.010%) and physicochemical properties (reactivity 4.35 and 8.07 cm 3 /g s, respectively; electrical resistivity 1.9 × 10 6 and 3.6 × 10 6 Ω cm, as against 3.6 Ω cm for coke). The reducing potential of the coal is significantly increased by the larger volume of reducing components H 2 and CO (23.2 and 18.3 times more than in coke) in the volatiles ( V daf = 42.4 and 47.0%) and the high reactivity of the solid residue after pyrolysis. Industrial experiments show that coal may be efficiently used instead of coke in the production of carbon ferromanganese and ferrosilicomanganese, thanks to the greater manganese extraction in the alloy and its lower phosphorus content.