Coal waste management by agglomeration of coal fines using non-edible vegetable oils

摘要

In the current scenario of ever-increasing energy demand and depleting fossil fuel resources, the effective utilization of coal resources minimizing their wastage is gaining ground. Huge quantities of coal fines generated at various stages of mining, beneficiation and utilization form slurries with water. The untreated disposal of these slurries is not only a cause of environmental concern, but also results in the loss of high energy coal fines. In the present study, the potential of oil agglomeration technique in the beneficiation and recovery of these coal fines was examined using Indian coal (+75-200μm) and non-edible vegetable oils such as Jatropha, Karanja and Rubber seed oils as bridging oils. The experiments were carried out at a slurry pulp density of 1.5%(w/v) and an agitation speed of 1100 rpm by varying the bridging oil concentration from 10% to 50% (w/w of coal). The maximum yield of agglomerates with Karanja oil was found to be 89.3% as compared to 86.3% with Jatropha oil and 85.9% with Rubber seed oil using 20% oil concentration. Maximum organic matter recovery (>90%) and significant ash rejection (>50%) were achieved using all the oils at the same concentration.