Experimental burning of used automotive crankcase oil in a dry-process cement kiln

An experimental program was carried out at the St. Lawrence Cement Company Limited, Mississauga, Ontario, in which 330,000 gallons of used lubricating oil was burned as a portion of the total fuel requirement for a dry-process cement kiln. The plant uses a dual four-stage preheater with a by-pass system. The oil was primarily composed of automotive crankcase drainings and contained approximately 0.6% lead, 0.15% bromine, 0.1% zinc and 0.1% phosphorus.Lead, zinc and phosphorus emissions in the kiln exhaust gases were not found to be increased during waste-oil burning. A small reduction in particulate emissions was found during waste-oil burning. A small increase in bromide emissions was found to occur during the waste-oil burn. A material balance was carried out for lead, bromine, zinc and phosphorus which indicated that these elements were retained in the process solids. Lead, zinc, phosphorus and some of the bromine were retained in the cement clinker. Most of the bromine was retained in the collected dust from the precipitator on the by-pass system.