Process and device for cleaning aluminium@ turnings - contaminated with oils and solids by washing in specified cleaning agent at relatively low temp., recovering turnings and reprocessing cleaning agent for reuse

摘要

Aluminium turnings contaminated with oily liquids and solids are cleaned in an aq. cleaning agent in a washing machine. The turnings are recovered, and the cleaning agent is reprocessed in a single stage operation using a three-phase decanter before recirculation to the washing machine. The cleaning agent is used at 5-60 deg.C and pH 8-12.5, and contains 1.5-3 wt.% of a mixture contg. 5-40% sodium tripolyphosphate, 3-10% sodium gluconate, 30-70% sodium carbonate, 3-8% of a mixture of non-ionic and anionic detergents at a concn. ratio of 1:2 to 2:1, 0.1-2% foam remover and 5-15% buffer soln. of the required pH. ADVANTAGE - Reduced apparatus requirements compared to prior art processes. Effective reprocessing of cleaning agent. Reduced energy requirements due to relatively low wash temp..