Brown corundum is smelt by bauxite in arc furnace. It has high rigidity and large tenacity so it is suitable to grind carbon steel, general alloy steel, malleable cast iron and hard bronze. It is widely used for casting of refractory products such as corundum and ramming materials.

Chemical composition of brown corundum： GB/T 2479-1996 Chemical composition (weight%) Trademark Granularity Al2O3 TiO2 CaO AA-P1 4#~80#(P80)(P100~P150) 95.00~97.50 1.50~3.80 ≤0.45 180#~220#(P180-P220) 94.00~97.50 220#(P220)以细 ≥92.00 A-BA-P2 4#~80#(P8~P80) ≥93.00 1.50~4.20 -------   90#~220#(P100~P220) ≥91.00   220#(P220)以细 ≥90.00 ≤4.50 ------- A-S 16#~220# ≥92.00 ≤4.20 ------- ■GranularityWA

White corundum uses high quality alumina powder as raw materials. It is produced by electric melting and refining of crystal. Its rigidity is slightly higher than that of brown corundum. White corundum has lower tenacity, high purity, excellent self-sharpening performance, strong grinding ability, small calorific value, high efficiency, acid and base corrosion resistance, high temperature resistance and excellent thermal stability. It can be used to produce abrasive tool so it is suitable to grind high-carbon steel and high-speed steel. It also can be used for abrasion and polishing of materials, precision casting, spraying, carrying agent of chemical medium, special ceramics and high-class refractory materials.  Chemical composition of white corundum： GB/T 2479-1996 Chemical composition (weight%) Trademark Granularity Al2O3 Na2O WA 12#~80# ≥98.50 ≤0.50 90#~150# ≥98.50 ≤0.60 180#~220# ≥98.20 ≤0.70 W63~W14 ≥98.00 ≤0.80 W10~W5 ≥97.50 ≤0.90 WA-B及WA-P 12#~80# (P12~P80) ≥98.20 ≤0.60 90#~150# (P100~P150) ≥98.00 ≤0.70 180#~220# (P180~P220) ≥98.00 ≤0.80 P240~P800 ≥98.00 ≤0.80 P1000~P1200 ≥97.50 ≤0.90 ■Pink fused alumina

　　Pink fused alumina also uses high quality alumina powder as raw materials. It is smelt in arc furnace by adding 0.5% to 2.0% of chromium oxide into alumina powder. It has color of magenta. Its application scope in grinding is similar to that of white corundum. However, its durability of abrasive tool and smoothness on surface of processed work piece are slightly better than those of white corundum. Therefore, it can be used for precision knives, measuring implements and instrument parts.

    Black silicon carbide uses quartz sand and petroleum coke or blind coal as main raw materials. It is produced in electric resistance furnace by high temperature. It has solid texture, sharp edge so it is suitable to manufacture grinding wheel, abrasive tool, compass saw, high-class refractory material and deoxidizer. It also can be used for grinding, polishing and sand blasting and so on.

Chemical composition of black silicon carbide:

GB/T 2480-1996		Chemical composition (weight%)
Trademark	Granularity	SiC	F.C	Fe2O3
C	12#~90# P12~P100	≥98.50	≤0.20	≤0.60
	100#~150# P120~P150	≥98.00	≤0.30	≤0.80
	180#~220# P180~P220	≥97.00	≤0.30	≤1.20
C-B C-P	12#~90# P12~P100	≥98.00	≤0.25	≤0.70
	100#~150# P120~P150	≥97.50	≤0.35	≤0.90
	80#~220# P180~P220	≥96.00	≤0.35	≤1.35

    Green silicon carbide uses quartz sand, petroleum coke and table salt as main raw materials. It is produced in electric resistance furnace by high temperature. Product is green with translucency. It has high purity, brittleness and rigidity so it is suitable to grind hard alloy, optical glass and ceramics and other hard and brittle non-metallic materials.

Chemical composition of green silicon carbide：