Sintered Spinels are alumina and magnesia composites in different ratios. The high-quality raw materials are from verified sources with detailed control of the production process. During sintering, alpha-alumina crystals are combined with magnesia crystals to shape grater crystals to shape greater crystals, which give spinels a unified crystal structure, low porosity, and high density.

The use of spinels in magnesite and alumina refractory products increase their thermal shock and corrosion resistance. GNPGraystar offers a broad range of sintered spinels, which are produced by crushing, grinding, mechanical and magnetic separation, and mixing of fractions.