Regeneration of cutting fluids by ultrafiltration - after treatment with hydrogen peroxide to promote oil sepn.

摘要

Recovery of active ingredients from used cutting fluids (coolant-lubricant fluids) is effected by (a) treating with 100-600 (pref. 150-300) ppm of H2O2, (b) separating an oil-rich upper phase after decompsn. of the H2O2, and (c) subjecting the oil-lean lower phase to ultrafiltration. Step (a) is pref. effected at 25-30 deg.C with a delay of 12-24 hr before step (b). Alternatively, step (a) can be effected at higher temp. (up to 90 deg.C) with a shorter delay. The process is esp. useful for treating oil-contaminated synthetic water-based cutting fluids contg. 2-3% amines and minor amts. of emulsifiers and stabilisers. Steps (a) and (b) greatly extend the life of the ultrafiltration membrane between regenerations.