High Alumina Bauxite

High alumina bauxite is also called high Alumina grog or aluminum ore. Its main component is alumina, which is hydrated alumina containing impurities. It is an earthy mineral. The types are divided into raw alumina and cooked alumina. Bauxite in the refractory industry usually refers to bauxite with a calcined Al₂O₃ >= 48% and low Fe₂O₃ content. High-alumina clinker is calcined bauxite. It is mainly used for precision casting in the aluminum smelting industry, refractory products, high alumina bauxite, aluminum silicate refractory fiber, and manufacturing of bauxite cement.

Physical and Chemical Index of high-alumina bauxite

Product Code	Chemical Composition (Mass Fraction),%					Bulk Density g/cm’	Water Absorption Rate  %
	Al2O3	Fe2O3	TiO2,	CaO+MgO	K2O+Na2O
GL-90	≥89.5	≤1.5	≤4.0	≤0.35	≤0.35	≥3.35	≤2.5
GL-88BA	≥87.5	≤1.6	≤4.0	≤0.4	≤0.4	≥3.20	≤3.0
GL-88B	≥87.5	≤2.0	≤4.0	≤0.4	≤0.4	≥3.25	≤3.0
GL-85A	≥85	≤1.8	≤4.0	≤0.4	≤0.4	≥3.10	≤3.0
GL-85B	≥85	≤2.0	≤4.5	≤0.4	≤0.4	≥2.90	≤5.0
GL-80	>80	≤2.0	≤4.0	≤0.5	≤0.5	≥2.90	≤5.0
GL-70	70~80	≤2.0	—	≤0.6	≤0.6	≥2.75	≤5.0
GL-60	60~70	≤2.0	—	≤0.6	≤0.6	≥2.65	≤5.0
GL-50	50~60	≤2.5	—	≤0.6	≤0.6	≥2.55	≤5.0

Introduction to bauxite clinker

Bauxite clinker, a high-aluminum material, is called cooked bauxite after raw bauxite is calcined at a high temperature (1200~1700℃). The main minerals of bauxite clinker are diaspore and high-alumina silica, and the diaspore content increases with the increase in the proportion of Al2O3 and SiO2. Secondary minerals include rutile, iron ore, etc.

Characteristics of high alumina bauxite

The refractory resistance of high-alumina bauxite clinker is as high as 1780°C. It has strong chemical stability, good physical properties, and a very significant refractory effect. Therefore, it is widely used in the metallurgical industry’s refractory and anti-corrosion materials. The clinker is processed into fine powder, made into casting molds, and then precision cast. It is used in the military, aerospace, communications, instrumentation, machinery, and medical equipment sectors.

Uses of bauxite clinker

Bauxite can be used as various high-alumina bricks and their clinkers and is widely used as refractory or anti-corrosion materials in the metallurgical industry and other industries, especially the tops of electric furnaces, blast furnaces, and hot blast furnaces. The refractory effect is very obvious and its performance is better than ordinary clay refractory bricks.

Classification of bauxite clinker

1. First-grade high-alumina bauxite refers to high-alumina bauxite with an iron content of less than 2.2%. It is usually used to make ceramics and high-end building materials. Due to the low iron content, the quality of the product is higher.
2. Secondary high-alumina bauxite refers to high-alumina bauxite with an iron content between 2.2% and 2.8%. It is usually used to make building materials and advanced refractory materials. Due to the lower iron content, higher quality products can be made.
3. Third-grade high-alumina bauxite refers to high-alumina bauxite with an iron content between 2.8% and 3.5%. Due to its slightly higher iron content, it is mainly used in the manufacture of general building materials and basic materials such as bricks and tiles.