Processing fine fractions of low-rank coals

CIM Bulletin, Vol. 79, No. 892, 1986

P. CARBINI, R. CICCU, C. DEL FA and M. GHIANI, Dipartimento di Ingegneria Mineraria e Mineralurgica, Centre Studi Geominerari e Mineralurgici del C.N.R., Universita di Cagliari, Cagliari, Italy

This paper is concerned with the problems inherent in the efficient and economical processing of the fine fractions of a coal from the Sulcis basin (Sardinia, Italy) whose characteristics are typical of low-rank coals occurring in the Mediterranean region. Three different techniques, based upon surface properties, are examined. Flotation can be very efficient from both a technical and economic point of view, provided care is taken in the modulation of the flotation pulp. Interesting results have been obtained with oil agglomeration and this method could be economically feasible. Finally, electrical separation has proven a viable technique, although it entails preliminary drying. Besides discussing the problems encountered in the experimental research, some significant results of general validity are also given. They demonstrate that cleaned products can be obtained with fairly interesting recoveries, thus opening the way to advanced research aimed at setting up the most suitable technique for industrial application.

Keywords: Coal preparation, Beneficiation, Flotation, Low-rank coals, Coal processing, Oil agglomeration, Electrostatic separation, Sulas basin.