Raw material bodies such as briquettes, for use in the production of silicon or silicon alloys, are formed by mixing a pitch and caking coal at a temperature above 100.degree. C. and up to 200.degree. C. to form a pitch/coal alloy. This hot binder composition is mixed with sand and a noncaking carbon carrier at a temperature in this range to form the starting composition from which preforms are pressed. The preforms are subjected to a heat treatment which involves raising the temperature to above 450.degree. C., preferably in a sand filled rotary furnace to harden the preforms into the bodies.