Alumina is a stable oxide of aluminum and its chemical formula is Al2O3. Bauxite is also called bauxite in mining, ceramics and material science. GN Decanter centrifuge are widely used for alumina slurry dewatering for production of alumina.
GN-CD series chemical decanter centrifuge are designed for the chemical treatment. Typically The alumina (Aluminum Hydroxide) slurring have a water content of 90%. And the purpose to treat the alumina is to remove water to get 20% to 40% content of slurry. And the Aluminum slurry contains alumina ( fine particles) water and sodium nitrate dissolved in water. Different client have different requirement for the capacity for the alumina slurry treatment.
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Application of alumina are very wide, include but not limited to following:
1. The main components of ruby and sapphire are alumina, which show different colours because of other impurities. Ruby is red with chromium oxide, while sapphire is blue with iron oxide and titanium oxide.
2. Among the main components of bauxite, the content of alumina is the highest. In industry, bauxite is purified into alumina by Bayer process, and then converted from Hall-Heroult process to aluminium metal.
3. Alumina is the reason why metallic aluminium is not easily corroded in air. Pure aluminium metal reacts easily with oxygen in the air to form a thin alumina film covering the surface of aluminium exposed to air. This alumina film prevents aluminium from being oxidized further. The thickness and properties of this oxide film can be enhanced by a process called anodic treatment (anodic anticorrosion).
4. Aluminum is a good conductor of electricity and heat. Aluminum crystal form diamond is suitable for grinding materials and cutting tools because of its high hardness.
5. Alumina powder is often used as a medium for chromatographic analysis.
China market for Alumina
The data show that China is the largest alumina producer in the world. In 2010, the global alumina output was 56.355 million tons. China’s alumina output reached 28.955 million tons, an increase of 20.14% year on year, accounting for 51.38% of the world’s total. In 2010, China’s apparent consumption of alumina reached 33.21 million tons, with an annual growth rate of 14.05%, net imports of 4.26 million tons, bauxite imports of 30.19 million tons, external dependence of 39.71%, and alumina external dependence of 47.26%.
With the rapid development of China’s electrolytic aluminum, ceramics, medicine, electronics, machinery and other industries, the market demand for alumina still has greater room for growth, and alumina production will continue to grow. GN Chemical Decanter Centrifuge made by GN separation and conveying equipment company