Abstract: A process for converting coal tar containing quinoline-insoluble particles (Q.I.) produces a substantially Q.I.-free coal tar pitch and a separate, Q.I.-containing coal tar pitch. Dehydrated coal tar, soft coal tar pitch or hard coal tar pitch are subjected to continuous cross flow filtration in a circulation loop to obtain a substantially Q.I.-free stream and, concurrently, a Q.I.-containing stream. The two streams are then separately subjected to further fractionation, if any, to produce the substantially Q.I.-free hard coal tar pitch and separate Q.I.-containing hard coal tar pitch.

Abstract: Continuous method for treating a liquid tar containing Q.I. solids to provide a liquid tar product having increased Q.I. concentration and, concurrently, a Q.I. free liquid tar product. The method utilizes cross-flow filter membranes.

Abstract: A process to form a uniform metal boride coating on a carbonaceous substrate by first forming a metal carbide coating and reacting the carbide coating with a boron compound.