EFFECTS OF OIL CONCENTRATION AND PARTICLE-SIZE ON THE CLEANING OF SPANISH HIGH-RANK COALS BY AGGLOMERATION WITH N-HEPTANE

The response of three high-ash Spanish anthracites to agglomeration with n-heptane was evaluated by measuring the organic matter recovery, ash rejection and pyritic sulfur rejection, The influence of oil concentration and coal particle size on the agglomeration results was investigated. The combustible recoveries of these coals increased to a maximum as the n-heptane concentration is raised, and then decreased. Ash rejection fell as the coal recovery increased. The effect of oil concentration on pyritic sulfur rejection was comparable with that on ash rejection. Regarding ash, pyritic sulfur was removed from one coal with noticeable selectivity. Ash rejection and organic matter recovery were improved by grinding one coal to < 45 mu m. Coal particle size had a more pronounced effect than n-heptane concentration on selectivity of oil agglomeration for cleaning this coal.