ANTISOLVENT-INDUCED AGGLOMERATION OF MINERAL MATTER IN COAL-DERIVED LIQUIDS.

The influence of many of the variables associated with anti-solvent induced agglomeration of mineral matter in coal derived liquids was observed by an indirect X-ray photographic measurement of sedimentation. The primary variables were anti-solvent type, dose, combinations of anti-solvent and gas, anti-solvent addition rate, and mixing properties. Also, the properties of the coal derived liquids have a great influence on the ash agglomeration and sedimentation. A correlation is proposed which relates the effectiveness of various anti-solvents, as evidenced by an increase in the initial settling rate, with their carbon/hydrogen ratio and solubility parameter. The advantage of this correlation over the ones proposed earlier is that it involves more fundamental and readily available properties of the anti-solvent. Anti-solvent mixture effects can be predicted by using molar weighted averages of the carbon/hydrogen ratio and solubility parameter. The coal derived liquids were characterized according to their solubilities in pentane, toluene and pyridine. The pentane insoluble and the toluene soluble are usually termed asphaltenes and the toluene insoluble but pyridine soluble are called preasphaltenes. It was found that increased preasphaltene content of the coal derived liquids greatly increased the efficiency of the anti-solvents for agglomeration and sedimentation.