Airco, Inc.

Rudolph W Wallouch

A method for increasing density and strength in baked carbonaceous products such as carbon or graphiteelectrodes. A baked carbonaceous body is subjected to a conventional pitch impregnation, and is then coated with a thermosetting polymerizable composition, which composition is at least partially cured to provide an encasing shell of polymeric material. The shell-encased body containing impregnated pitch is thereafter subjected to carbonization by rebaking. During rebake, the shell is mechanically stable to temperatures above the softening and free flowing temperatures for the impregnant, whereby the shell (which is decomposed and carbonized as higher temperatures are attained) acts during initial stages of carbonization to retain the impregnant within the body. This results in larger quantities of coked impregnant remaining in the body with consequent higher apparent density and strength in the resultant product. The product can then, as desired, by subjected to a conventional heating schedule to effect graphitization.

Method for increasing the strength and density of carbonaceous products

An improved graphite nipple for connecting contiguous lengths of graphite furnace electrodes. The nipple is of the type having a reservoir for a thread locking pitch composition. The reservoir contains a heat-foamable, thermoplastic material including particulate pitch in a lignin sulfonate-based binder. The composition may be deposited into the reservoirs of the nipples by direct extrusion at ambient temperatures. When a nipple thus prepared is utilized in an electrode joint assembly, the high temperatures provided at the electrode joint foam the composition to expand it into adjacent thread spaces at the joint. Continued heating then carbonizes the composition to lock the joint.

Nipple for electrode joint

A locking pitch composition for depositing within the pitch reservoir of graphite nipples of the type including such voids. The composition is a heat-foamable, thermoplastic material including particulate pitch in a lignin sulfonate-based binder. The composition may be deposited into the reservoirs of the nipples by direct extrusion at ambient temperatures. When a nipple thus prepared is utilized in an electrode joint assembly, the high temperatures provided at the electrode joint foam the composition to expand it into adjacent thread spaces at the joint. Continued heating then carbonizes the composition to lock the joint.

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Lewiston, NY, United States of America

Rudolph W Wallouch