Method of production of solids-free coal tar pitch
 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. 
UCAR Carbon Technology Corporation
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inventional inventional
Thomas Harry Richard L. Irwin C. Ching F.
Orac Shao Lewis Chang