... purification ,crystal, choosing, magnetic, screening, etc. The brown fused alumina of our factory had high purity,detailed texture ... .5-3.81.5max1.3max Physical properties ColorDark Brown Moh's hardness9.0melting point2250°Cmaximum service temperature ... shell filters, garnet filters, polishing sands, rust sands, sponge iron, medical stones, ceramic filters, manganese sand filters, zeolite filters ...