Domtar Inc.

Other

Henry A Kremer

Samuel Cukier

The present invention relates to specialty pitches having low Q.I. content, lower viscosity, lower average Q.I. particle size, lower ash content, higher toluene insoluble and beta-resin content. They may be prepared by extracting the coal-tar material with a solvent, where the solvent contains at least one n-methyl-2-pyrrolidone and the wash oil fraction of coal-tar distillate. The solvent-dissolved fraction of the coal-tar material is then distilled to obtain the specialty pitch material.

Modified coal-tar pitch

The present invention relates to a process for decreasing and modifying the quinoline-insoluble content (Q.I.) of coal-tar materials; and comprises extracting the coal-tar material with a solvent, where the solvent contains at least one of n-methyl-2-pyrrolidone and the wash oil fraction of coal-tar distillate. Pitches with a diminished Q.I. content, lower viscosity and lower average Q.I. particle size, may be prepared from coal-tar materials which have been so treated.

Process for modifying coal tar materials

A new oxidation-resistant pitch composition is obtained by treating in the molten state a coal tar or petroleum pitch with at least one pitch-soluble and compatible alkyl-aryl sulfonic acid or some salts thereof in an amount of less than 1% of said pitch, with a pitch suitable for making an electrode treated that way, upon subsequent carbonization in conjunction with petroleum coke, an electrode can be formed, with great resistance to oxidation, and with very little dusting. Due to increased coking value of the pitch, the fuming is decreased both during the art of making electrodes and during the use of same in the actual electrolysis thus providing environmental benefits. Such a pitch may also be used as a refractory material.

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Thornhill, Canada

Henry A Kremer