Calcium carbide prodn. from calcium oxide and carbonaceous cpd. - derived from crushed plastics waste pyrolysed in presence of calcium oxide

摘要

Calcium carbide is produced by reacting calcium oxide with a carbon-contg. component in an electric arc furnace, said component being produced from crushed plastic waste which undergoes pyrolysis in the presence of granular CaO at 600-1300 deg.C in a rotary kiln. Thermoplastic waste, namely polyethylene, polypropylene and polystyrene, contg. 70-85 wt.% C is crushed to obtain particles of max. size 20 nm, pref. 1-5 mm.. Granular CaO, particle size max. 2 mm, pref. max. 1 mm, in the form of calcined lime or anhydrous calcium hydroxide is mixed with the plastic waste at a wt. ratio of 1:1-3, this mixt. being compressed prior to pyrolysis to form pellets 10-50 mm in size. Environmentally-friendly and virtually complete utilisation of waste plastic. A carbon-contg. component for calcium carbide mfr. is produced from low-cost raw materials. The exhaust gases produced by pyrolysis are high purity and may be used for power generation.