Chemical Engineering - Chemical Engineering Basics - Discussion

Ans : D (Al2O3).

Aluminum oxide or fused corundum (Al2O3) is a crystalline aluminum oxide obtained from bauxite clay containing about 60% of aluminum. It is referred to as the fused corundum due to the technology of its production in electric arc furnaces.

The purity percentage of aluminum oxide (94"99%) and degree of its hardness makes it one of the varieties of grain used for manufacture of grinding or cutoff wheels or other abrasive tools for processing of wood or metals.

Aluminum oxide is the most common abrasive used in grinding wheels. It is usually the abrasive chosen for grinding carbon steel, alloy steel, high-speed steel, annealed malleable iron, wrought iron, and bronzes and similar metals while Silicon carbide is an abrasive used for grinding gray iron, chilled iron, brass, soft bronze and aluminum, as well as stone, rubber and other non-ferrous materials.

Aluminum oxide is the most common abrasive used in grinding wheels. It is usually the abrasive chosen for grinding carbon steel, alloy steel, high-speed steel, annealed malleable iron, wrought iron, and bronzes and similar metals while Silicon carbide is an abrasive used for grinding gray iron, chilled iron, brass, soft bronze and aluminum, as well as stone, rubber and other non-ferrous materials.

Aluminum oxide (Al203) is the most common abrasive used in grinding wheels. It is usually the abrasive chosen for grinding carbon steel, alloy steel, high-speed steel, annealed malleable iron, wrought iron, and bronzes and similar metals while Silicon carbide is also can be used but due to availability & Cost with Respect to Performance.

Oxide of metals have tendency of alkalinity but some do not follow. Aluminium is one of those. Aluminium oxide is neutral compound and this is neither acidic nor alkaline. It does not react with cutting tools. This may be one of the reason.

Aluminium oxide is formed in the form of harsh white crystals, which do not dissolve neither in the acids nor the bases, and show no desire for moisture (hydration).

Aluminium oxide is used for general purposes while Silicon carbide is harder and brittle so it is used for stones, cement and chilled iron.

Silicon carbide is mostly used material for making cutting tool, but aluminium oxide is cheaper than silicon and it has lower capacity.

Silicon carbide or aluminum oxide are both used. But, when cost and readily available material is needed Aluminium oxide is used.

Aluminum is a generally soft, nonferrous, ductile material with low density and naturally high resistance to corrosion.