The reliability of the operation of an induction crucible furnace of industrial frequency (IFC) used in the foundry industry depends on the durability of its lining. For this reason, a lot of research work is devoted to quartzite, as the cheapest material of the acidic lining, both in our country and abroad. The goal of the research is to develop the technology for the manufacture and operation of acid lining, which is used for smelting alloys at operating melting temperatures above 1450 ° C. The effect of melting temperature regimes on changes in interplanar distances in the structure of quartzite, affecting the stability of the furnace lining, is considered.Ill.4. Ref. 14.