Metallurgical Quartz

In ferroalloy production, quartz is charged into electric arc furnaces together with carbon based reductants and used as a silicon source. Two basic properties are expected from the raw material in this process: a high SiO₂ content, and the ability to keep its form without disintegrating when heated inside the furnace. Material that breaks up on rapid heating creates fines inside the furnace, which disturbs the gas permeability of the charge and lowers efficiency. In metallurgical use, grain strength is therefore at least as important as chemical purity.

The second main metallurgical use of quartz is in acid-lined melting furnaces. The silica based ramming mass blends used in induction furnaces are prepared by mixing graded fractions from coarse to fine in defined proportions. Graded granulometry allows the lining to form a dense, void-free structure when compacted; this prevents liquid metal from penetrating into the lining and extends lining life. With a melting temperature of 1710 °C, quartz maintains its stability at iron and steel melting temperatures.

Quartz is also used together with binders in refractory mortars, repair materials and furnace patching mixes. In steelmaking it serves as a silica source for adjusting the fluidity and basicity of the slag; the correct slag composition directly affects both lining wear and metal quality. Depending on the application, different fractions are required, from coarse lumps through to micronized fineness; we determine the fraction distribution suited to the furnace type and lining recipe of your plant together with you and supply accordingly.