EMPIRICAL MULTIPARAMETRIC RELATIONSHIPS BETWEEN COAL-TAR PITCH EXTRACTION YIELDS IN ORGANIC-SOLVENTS AND SOLUBILITY PARAMETER COMPONENTS OF THE SOLVENTS

In this paper an empirical study of the quantitative multiparametric relationships between coal tar pitch extraction yields and solvent solubility parameter components is reported. The best equations are of the same form as the theoretical equations for the solute-solvent equilibrium state. It has again been proved that the greater the solvent dispersive or non-polar solubility parameter component the greater the extraction yield. The other components of the solubility parameter contribute to increase the extraction yield only if they do not exceed certain values. The equations obtained are also able to satisfactorily predict the coal tar pitch extraction yield in other solvents not involved in their derivation.