Classification of brown coal fly ash fractions by wet, magnetic separation methods, and determination of physical, morphological, and chemical properties of separated fractions, Part 1

Article presents method of fly ash separation with the use of flotation followed by magnetic separation. Properties of so obtained fly ash fractions were also presented. Fly ash obtained from brown coal combustion was separated into three fractions in floatation pool. Next, each fraction was air dried and subjected to magnetic separation using permanent magnet placed over conveyer belt. Upper layer of particles obtained during flotation consisted mainly of cenospheres. Second layer was composed of round and oval particles, some of them containing fine pores. Particle size distribution of grains in second layer was the finest. Bottom layer contained mainly coarse irregular grains rich in iron. Fractions separated by magnetic separation were characterized by increased iron content, even up to 40% of Fe2O3 as well as coarser grain size comparing to raw fly ash. Magnetic particles contents in upper, middle and bottom layers were 2%, 4% and 15% respectively.