An aq. emulsion of corn. engine oil (10 g/L) was produced by pomp circulation and in presence of a surfactant and sepd. by using porous SiO(2) discs at 50 degrees C, 0.17 MPa and ultrasonic treatment. The discs were formed by pressing a mixt. of quartz sand, cryolite, cullet dust, H(3)BO(3) and aq. soln. of dextrin under 10 MPa, sintering at 900 degrees C for 1 h and impregnating with silane resins or ZnO. The highest concn. cif the oil phase was achieved when ZnO-impregnated discs were used.