Beneficiation of Fine Coal Tailings From Coal Preparation Plant by Enhanced Gravity Methods

Abstract

In the past, it was more economical to dispose fine coal without utilization. Nowadays, beneficiation of fine coal is a necessity due to increasing costs of mining, tailings disposal and storage problems. This research contains experimental studies devoted to beneficiation of <0.1 mm coal preparation plant tailings of Garp Lignite Enterprises (Tunçbilek-Kütahya/Turkey). It was found from the characterization studies that the coal tailings include clay minerals (kaolinite, mica/illite, and smectite group), quartz, siderite, pyrite and dolomite which are of higher density than lignitic coal. Concentration processes are proposed as preliminary and final. In the preliminary two-stage processing tests, hydrocyclone is used to separate clay minerals associated with coal. For this purpose, structural and operating parameters of hydrocyclone (hydrocyclone diameter, vortex diameter, apex diameter, feed inlet pressure, pulp solids ratio) and of Falcon concentrator (gravity force, feed rate, pulp solid ratio and wash water pressure) are optimized, and their influences on separation efficiency were discussed. Under optimum conditions, a fine clean coal concentrate assaying 35.66% ash and 1.63% total sulfur at a recovery of 34.60% was obtained.