Desulphurising of molten metals, esp. crude iron or steel - using mixed crystals of calcium carbide and calcium oxide which is partly hydrated

摘要

Agent is made by a melting process, which produces mixed crystals (I) contg. CaC2 and CaO; and part of the CaO is hydrated to form Ca(OH)2. Crystals (I) pref. contain by wt. 40-80% CaO, esp. either 45-80%, or 40-65% CaO; and the CaO is pref. hydrated so that crystals (I) contain 1-6%, esp. 2.5-3.5% combined water. Crystals (I) are pref. made by the usual process employed to mfr. CaC2, and are then pre-crushed and the fines below 4 mm in size discarded. The remainder is milled in the presence of air or N2 contg. 5-20 g/cu.m moisture to a size below 10 mm. The agent can be mfd. economically, and has a high yield when removing sulphur from crude iron or steel.