METHOD OF PREPARING CALCIUM CARBIDE Russian patent published in 1999 - IPC

FIELD: chemical industry, more particularly production of acetylene and melting of steel. SUBSTANCE: coke-ash residue resulting from thermal processing of oxidized brown coals comprises (wt %): CaO 47.5; C, 35.4; Fe₂O₃, 6.6; SiO₂, 5.0; Mg, 3.3; Al₂O₃, 1.6; S, 0.1 and the balance, 0.5, is mixed with 12.9-28.3% calcium carbonate based on mixture weight. The whole is subjected to high-temperature melting at 2000-2100 C, then cooled to separate CaC₂ and ferrosilicium. Method does not require expensive products. CaC₂ content is 275-285 l/kg and ferrosilicium content is 0.1-0.2 wt %. EFFECT: more efficient preparation method. 2 cl, 3 ex