Bentonite bound foundry moulding sand conditioning process - by heat treatment of precleaned sand for high quality sand useful for core prodn.

摘要

Conditioning comprises precleaning of sand and then heat treatment of cleaned sand. Pref. heat treatment is at 800-1000 deg.C and is until a regenerate pH value of less than 8.5 (about 7) is obtd. An acid neutralising agent is added to the precleaned sand during heat treatment. Post-treatment includes cooling, dust sepn. and classifying/sifting. Process appts. is based on a gas tight barrel furnace (indirect heated rotary tube furnace) with preheating of combustion air by cooling the regenerate and instrumentation for measuring pH value. USE/ADVANTAGE - High quality sand used for core prodn.