No.5 Influences of pH variations on coal cleaning and desulfurization efficiency during oil agglomeration processes

Abstract

Nowadays, the oil agglomeration processes have been developed for reducing and making beneficial use of waste fine coal from the mechanic coal mining and coal cleaning. In this study, we recovered the carbonaceous contents from waste fine coal based on an oil agglomeration process using vegetable oil. At same time, we improved reduction ratio of pyrite sulfur which is usually difficult to be separated during the oil agglomeration process. In this study, we adjusted pH of the solution of oil agglomeration from neutrality to basic, in order to separate pyrite sulfur effectively from waste fine coal under the basic condition. During the high basic condition, pyrite sulfur reduction indicated high values since the pyrite surface became hydrophilic. As the results, the pyrite contents will not be recovered together with hydrophobic carbonaceous contents. However, coal cleaning efficiency, especially combustible matter recovery decreased under high basic solution.