A new approach to performance optimization in coal flotation

Coking coal constitutes nearly 30% of steel production cost in India. Coal preparation plants are hard pressed to reduce the washing cost. Reagents appear to constitute a minimum 45% of the coal flotation and associated dewatering cost in India. Contribution of frother alone to total reagent cost is around 30%. There can possibly be no universal frother which would perform best irrespective of fluctuation in feed characteristics, typical for coking coal preparation plants in India. Plant operators however face difficulty in quick selection of a frother from among those supplied by different manufacturers. Therefore, an index has been proposed which takes into account all major performance parameters in coal flotation such as yield, misplacement, ash, selectivity, flotation rate and reagent cost. Performance optimization has been carried out through cost analysis. Lower the unit cost, better the frother. Lowest the unit cost, best is the flotation performance.