Removing oil from metal residue esp. from metal machining - by washing with detergent soln. in mill contg. grinding elements and polymer surfactant

摘要

Working up oily metal residues (I) esp. from metal machining, involves washing with an aq. detergent soln. (II) if necessary after preliminary removal of oil and pulverisation followed by sepn. and drying. Milling (SiC, washing according to text) is carried out in a tower (grinding) or (agitator) ball mill contg. grinding elements by operating the mill for up to 2 hrs. Pref. the coarser fractions of (I), with particle sizes of over 2mm, are used as milling elements. (II) contains a combination of nonionic and anionic surfactants, pref. an alkylphenyl polyglycol ether and an alkyl benzene-sulphonate. It may also contain alkali polyphosphate, alkali sulphate and water glass. USE/ADVANTAGE - The technique is suitable for working up (I), including very finely-divided (I) with very high oil contents. It reduces the oil content to under 0.5% and also removes abrasive particles. (3pp Dwg.No.0/0)