Pilot scale column flotation studies on the beneficiation of coal fines

Abstract

Large quantities of fines are generated during mining and preparation of coal. Froth flotation continues to be the most widely accepted technology for the treatment of slurry forming fines (- 0.5 mm), particularly when they are of coking variety. Beneficiation of coal fines with high ash was attempted by column flotation. A 0.5 m diameter pilot scale flotation column, designed and developed by CSIR - NML Madras Centre was installed at Jamadoba Coal Preparation Plant (JCPP) of M/s TATA Steel, to study the efficacy of column flotation technology for coal beneficiation. The yield of froth from flotation column, averaged over days of operation, was found to be 67.6% with an ash content of 14.1%. The average feed grade during this period was 25.2% ash and the tailings analyzed 48.3% ash. During the same period, froth from conventional flotation circuit analyzed 14.6% ash with 66.5% yield. The tailings of the conventional cell analyze 49.0% ash for the coal feed assaying 26.1% ash. Though the performance of flotation column is at par with the conventional flotation cells, the operational flexibility, low operational, maintenance and energy costs are attractive features of flotation column that lead to financial accruals over a long run.