Fluidized bed dry dense medium coal beneficiation

Abstract

Coal beneficiation in South Africa is currently conducted mostly on a wet “float and sink” basis. This process is heavily water intensive and also potentially polluting. Dry beneficiation alternatives are being sought. The alternative of dry dense medium beneficiation using a fluidized bed was investigated. Bed materials of sand, magnetite and ilmenite were used in a laboratory sized cylindrical fluidized bed. The materials were individually tested, as were mixes of sand and heavy minerals. Coal particles were simulated using vials of varying density. The sand experiments proved that dry beneficiation is feasible, and with the addition of heavier components the point at which coal can be split can be altered. The experiments with magnetite were unsuccessful, whereas ilmenite proved successful. This should however not eliminate magnetite as a viable option and it must be further investigated before an economic study is conducted. The experimental programme and results are discussed and presented.