Improvement of Lignite Oil Agglomeration by Ultrasound Process Using Waste Engine Oil

Abstract

In the present study, it was aimed to clean fine coal with waste engine oil using the ultrasound process. The influence of ultrasound on the oil agglomeration of coal was determined using ultrasound at the pretreatment stage and at the agglomeration stage. In this context, the use of ultrasound at the pretreatment stage improved the oil agglomeration of coal, but the use of ultrasound at the agglomeration stage reduced the recovery of combustible matter. Also, the power of ultrasound and the time of treatment affected the success of agglomeration, and the optimal values were achieved at a power of 30 W of ultrasound and a treatment time of 3 min. In addition, the best ash content and combustible matter recovery values were obtained at the oil dosage value of 3 mL, but higher oil dosages adversely affected the success of agglomeration. Under optimal conditions, coal with an ash content of 15.02% was obtained with an efficiency of 61.29% in conventional experiments, while coal with an ash content of 9.65% with ultrasound pretreatment was obtained with an efficiency of 71.04%. These results show that ultrasound pretreatment is an effective method for the enrichment of fine particle coal.