RECOVERY OF RESIDUAL LUBRICATING OIL FROM WASTE CLAY BY FLOTATION

The waste clay produced from refining waste lubricating oil contains a bout 30% oil. Laboratory research has been carried out on the selectiv e separation of oil by flotation using linear barium alkyl benzene sul fonates as a collector. The behaviour of this collector at the solutio n-air interface is studied; the critical micelle concentration (CMC), efficiency (II), and effectiveness (P-C30) of the collector are determ ined. The effects of collector concentration and addition mode are inv estigated. The liquid-vapour interfacial tension was controlled by met hanol. The selectivity achieved by the use of methanol is explained in terms of critical surface tension of floatability and CMC. In additio n the physico-chemical characteristics of the recovered oil at optimum conditions are determined.