Recycling of Waste Mill Oil through Non-recovery Coke Making

A plant scale trial was conducted to recycle the mill oil waste through non recovery coke oven route. The waste mill oil was added in the coal blend as a binder before hammer mill and charged in the ovens. JSW Steel has non-recovery coke ovens synergized with vibro-compaction technology to produce coke of 1.2 Mtpa. About 300 L of the mill oil which is generated in the hot strip mill daily was used in the trial. A cake density of 1.1 t/m3 has been achieved using vibro-compaction with optimized moisture, oil addition and crushing fineness. The coke produced with and without oil of same coal blend and coking conditions, was tested and compared. It is observed that utilization of mill oil has not shown any deteriorating effect on coke quality. There is a marginal increase in flue gas as well as oven crown temperature which helped to increase the power generation. This present paper describes the effect of mill oil addition on coke quality and the oven thermal conditions and the feasibility of recycling the waste through non recovery coke ovens at JSW Steel Ltd.