Improved performance direct bonded basic refractory brick and method of manufacture

摘要

This invention provides improved high fired direct bonded basic magnesite-chrome refractory shapes, such as brick, characterized by the presence of chromium enriched spinel structures distributed in the matrix and bonding the individual periclase crystals. The shapes are thermally stable and resistant to slag penetration and erosion and enjoy improved service life in industrial furnace linings. Also provided is a method of making the improved refractory shapes which comprises forming a mixture of (1) from about 40% to about 75% by weight high purity magnesite, (2) from about 25% to about 60% by weight chrome ore and (3) from about 0.5% to about 10% by weight chromic oxide powder; pressing the mixture into a refractory shape; and firing the refractory shape to a temperature of at least 1700 DEG C.