Effect of Calcium Aluminate-Based Additive on Properties of Periclase-Carbon Refractories for Steel-Teeming Ladles

Abstract

Premature decommissioning of a steel-teeming ladle lining due to critical localized damage, which significantly reduces lining functional properties, is one of the most acute problems in modern metallurgy. The main type of products used for steel-teeming ladle lining is periclase-carbon. In order to improve corrosion resistance and resistance to thermomechanical loads, additional additives, such as spinel, and high alumina CMA cement, are introduced into periclase-carbon products. In this article the effect of calcium aluminate-based additive on the properties of periclase carbon refractories is investigated. It is assumed that there is a potential for formation of magnesium aluminate spinel (MA) in periclase-carbon products with calcium-aluminate additives during heat treatment. Fused periclase is used as the raw material, the carbon component is represented by natural flaky graphite in an amount of 10 wt.%, and a combined binder. An additive based upon calcium aluminates is introduced, with a fractional size from 0 to 3 mm, while the amount of main fractions of fused periclase is reduced by the corresponding amount of the additive introduced. The compressive strength, apparent porosity, and bending strength values before and after coking firing are analyzed. The thermal coefficient of linear expansion, phase composition and microstructure of the products are also investigated.