Refractories as Advanced Structural Materials for High Temperature Processing Industries

Abstract

AbstractRefractories are essential structural materials used in different furnaces in industries processing steel, cement, non-ferrous metals, glass and other high temperature goods and products. This paper deals with current practices of refractories for ferrous as well as non-ferrous industries and its future scope. Al2O3 and MgO-based refractories are mostly consumed in the steel industry. High performance MgO–C is the refractory for basic oxygen furnace (BOF) for the last 30 years because of its excellent thermal shock property and corrosion resistance to steel slag. However, the contamination of carbon from refractory makes it difficult to produce high grade steel. Therefore, research on introducing nano-carbon in oxide–carbon refractory is going on to obtain high grade low-carbon steel without affecting the refractory properties. Functional refractory components for continuous casting such as slide gate plate, shroud, and submerged entry nozzles include Al2O3–C/ ZrO2–C. Incorporation of non-oxide materials like SiAlON, BN etc. further enrich refractory properties. In non-ferrous metal sectors e.g., in copper smelter, mag-chrome is the only option as working lining due to its resistance to fayalite slag. Globally, research is going on to develop environment friendly chrome-free refractory such as ZrO2–Al2O3 and Mag–Al Spinel for non-ferrous and cement industries. Good quality raw materials are one of the primary requirements to produce refractories with improved properties. In India, as good quality refractory raw materials are not available, focus is on to upgrade the available materials through proper processing. Judicious recycling of used refractory is another option to partially substitute for virgin raw materials.