摘要 |
1. Process for making calcium carbide from lime and a carbon carrier in a closed electrothermal furnace with a power of more than 20 megawatts, in which the electrodes are arranged symmetrically in the corners of an equilateral triangle, which comprises : using at least 40% of the total carbon component in the furnace burden in the form of a carbon carrier consisting of anthracite, petroleum coke and/or lean coal, the carbon carrier with an initial content of volatile constituents of more than 5.0% having been subjected to thermal pretreatment at increased temperature for as long as necessary to establish a residual content of volatile constituents of less than 5.0% and having been separated into a fraction consisting of particles with a size of 3 to 10 mm and into a fraction consisting of particles with a size of more than 10 up to 25 mm ; the fraction of smaller particles being introduced into a central region inside the furnace lying between the electrodes, and the fraction of larger particles being introduced into a peripheral region of the burden surface area inside the furnace which lies outside the triangle formed by the electrodes. |