Heating element composition and method for preparing tube fillings of high electrical resistance from fused magnesium oxide for tubular electric heating elements

Abstract

An electrical heating element composition comprising crystals of fused magnesium oxide improved by the inclusion of 0.05 to 5% by weight, based on the weight of said fused magnesium oxide, of an additive composition which has excellent lubricating properties in respect of the magnesium oxide crystals and reacts at 800.degree. to 1050.degree. C with active conductivity centers at the surface of one or more adjacent magnesium oxide crystals; an improvement in the preparation of an electrical heating element wherein a granular fused magnesium oxide composition is subjected to mechanical shaping and calcination which comprises employing as the electrical heating element composition a composition comprising crystals of fused magnesium oxide and 0.05 to 5% by weight, based on the weight of said fused magnesium oxide, of an additive composition which has excellent lubricating properties in respect of the magnesium oxide crystals and reacts at 800.degree. to 1050.degree. C with the active conductivity centers at the surface of one or more adjacent magnesium oxide crystals.

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