Process for the preparation of calcium carbide

摘要

The invention relates to a process for the preparation of calcium carbide from a calcium-containing starting material and carbon in an electric-arc furnace. Gypsum is used as the calcium-containing starting material. The gypsum is first mixed with carbon, and the mixture is made into briquettes by the hot-briquetting method. The briquettes represent the feed of the arc furnace. In the arc furnace, the gypsum in the briquettes is first reduced to calcium sulphide at a temperature of 800 to 1200 DEG C. The calcium sulphide is then reacted with the carbon of the briquettes at a temperature of about 1900 DEG C to give calcium carbide, and sulphur vapour to be discharged. The sulphur can be further processed to give sulphuric acid.