REFRACTORY MATERIAL

Mill Scale

Mill scale is formed on the outer surfaces of plates, sheets or profiles when they are being produced by rolling red hot iron or steel billets in rolling mills. Mill scale is bluish-black in color.

Process steps where hot metal surfaces are growing scales are:

  • Steelmaking: continuous casting, flame scarfing,
  • Hot rolling: reheating furnaces, rolling mill
  • Hot press & hot forming (minor processes for very large products). In most annealing furnaces the oxygen atmosphere is a too low to grow scale.

A submerged arc furnace produces foundry iron from scrap iron and steel sources where little or no slag is produced. Scrap iron or steel is fed into the submerged arc furnace with a source of silica and a carbonaceous reducing agent. The scrap iron and steel is melted while simultaneously smelting the silica in the presence of the carbonaceous reducing agent. Suitable sources of iron for use in the present invention include mill scale