Calcium carbide prodn. from calcium oxide and carbon component - obtd. from synthetic waste by pyrolysis and partial combustion of pyrolysis gas

摘要

CaC2 is prepd. by reacting a carbonaceous component with CaO in an electric arc furnace, using as carbonaceous component comminuted synthetic wastes which have been prepd. by (a) pyrolysis at 600-1000 deg.C, (b) partial combustion at 1200-1900 deg.C of the pyrolysis gas from stage (a) and (c) cooling of the C black/gas mixt. to 450-800 deg.C or sepn. of the C black with finely divided or lumpy CaO. The synthetic waste has a particle size of 1-100mm and a C content of 70-85 wt.%. Thermoplasts, comprising polyethylene, polypropylene or polystyrene are pref.. (a) Pyrolysis is in presence of up to 20% of CaO, w.r.t. the waste. (b) Partial combustion is in presence of less than the stoichiometric amt. of pre-heated air, w.r.t. the amt. of waste, opt. in a C black reactor. USE/ADVANTAGE - CaC2 is used in, e.g. prodn. of Ca cyanamide, NCN derivs., and C2H2 and C2H2 prods., and as desulphurisation agent in the Fe and steel industry. Synthetic waste is utilised completely and without harm to the environment, and a cheap C component for CaC2 prodn. is obtd.