Study On Separation Macerals In Shenfu Coals By Flotation

Under the situation of energy crisis in the world, the utilizations of coal are expandedand the requirements of coal are increasing day by day. The study of macerals separationcould be further clarified quality characteristics and quality evaluation of coal, also it couldpromote coal integrated and efficient use. In order to achieve key technical problems ofmacerals effective separation, this paper aimed to achieve effective dissociation with crushingand enrichment with flotation, the influence of the dissociation of macerals by differentcrushing methods was explored, and the effect of the separation and enrichment of maceralswith different flotation reagents, which provided a theoretical basis to separation andenrichment of macerals with flotation.Taking Shenfu coal as the research object, explored crushing characteristics andproduct features of rod milling grinding, ball milling grinding and jet milling grindingmethods, the effect of the dissociation of macerals with grinding time and crushing pressurefactor was studied, the grinding samples were tested by sizing and float and sink analyze. Theresults indicated that fine fraction was increasing with the rod mill and ball mill grinding timeincreased, but the product of coal yield changed little with the increasing of jet millingpressure. The heavy density content in coarse coal was higher with screening, and the highercontent of low density components in fine coal was also higher. The grinding and sievingprocess of coal macerals have difference enrichment phenomenon, namely the vitrinite easilyenriched in the coarse coal samples, and vitrinite easily enriched in fine particle in coalsamples. The float and sink test showed that coal maceral dissociation of rod grinding is betterthan that of ball milling and grinding and jet milling, which fine fraction was higher, and coalmacerals decomposed might be more fully. The better grinding time was6min and2min byrod milling and ball milling and jet milling pressure was0.6MPa for the Shenfu coal maceralsfrom the best dissociation and less aggregation.Based on the study of coal wettability and surface potential, the effect of different types and dosage of flotation reagents, types and dosage of flocculants on the separation andenrichment of macerals was studied in this paper. The results shown that, the separationresults were better of cationic collector than those of anionic collector and non-ionic collector.When cationic dodecylamine was used as collector, the enrichment rates of vitrinite in floatsand inertinite in sinks could be reached83.29%and47.44%, respectively. Combined with thecharging effect and flocculation effect of flocculants, the technology and process were putforward of the flocculant and collector mixed used in Shenfu coal macerals separation. Thefloats yield regularity was decreasing of polymeric aluminum chloride, two dimethyl diallylammonium chloride and polyacrylamide, and sinks yield laws were just the opposite and thedifference was little. Effects of different types of flocculants on Shenfu coal maceralsenrichment were different. It has better enrichment of macerals with inorganic polymerflocculants of polymerization aluminum chloride(PAC), and the effect was followed byorganic polymer cationic flocculant of two dimethyl diallyl ammonium chloride, then maceralenrichment was poor of organic polymer anion type of polyacrylamide flocculant. Thefloatation results were well with the combinated use of dodecylamine and PAC as collector,and the enrichment rates of vitrinite in floats and inertinite in sinks could be reached93.20%and50.79%, respectively.