Utilisation of spent alkali cyanides in glass prodn - by melting them with quartz sand and opt calcium carbonate

摘要

Spent alkali cyanides used in metallurgy as hardening agents are safely utilised by melting them with quartz sand to produce water glass, or with quartz sand and calcium carbonate to produce glass. Cyanides are converted into relatively harmless cyanates by firing in oxidising conditions even at a relatively low temp.; at high temps., CO2 and N2 are formed and expelled. Alkali values are recovered.