Calcined Bauxite

  1. PRODUCT AND ITS APPLICATION: 

Calcined bauxite is an important raw material for two main products, refractory and abrasives. Smaller volumes are consumed in other applications including proppant, welding fluxes and antiskid surface. While the process of calcining bauxite for each of these applications is fundamentally the same (i.e. it involve the same basic burning process), the physical and chemical characteristic of each grade vary. Calcined bauxite is classified by the major end use abrasive and refractory.

Calcined Bauxite is obtained by calcining (heating) superior grade Bauxite at high temperature (from 850 oC to 1600 oC). This removes moisture thereby increasing the alumina content. Compared to an alumina content of about 57 % to 58 % in raw Bauxite, Calcined Bauxite has an alumina content of 82 % to 86 %. The heating is carried out in rotary kilns. Calcination is done at different temperatures ranging from 850 oC to 1600 oC depending upon the customer’s application.

We export Calcined Bauxite for various applications such as refractory bricks, abrasives, steel polishing, etc. We provide consistency in quality and availability of Calcined Bauxite at extremely competitive prices.

Applications of Calcined Bauxite

  • Refractory Grade Calcined Bauxite (CB – I and CB – II Grade) : To make refractory grade, Bauxite is thermally treated at 1600 oC to produce Calcined Bauxite where the Alumina content is mostly above 82%.
  • Brown Fused Alumina, Proppants and Road Surfacing : To make the above grades, Bauxite is thermally treated at 1000 oC – 1200 oC to produce Calcined Bauxite where the Alumina content is anywhere between 80-88% depending on the requirement.

Specifications

Refractory Grade

Other Grades

Parameters CB – I CB-II BFA Grade Proppant Grade Road Surfacing Grade
Al2O3 MIN 83.00% 85.00% 85-88% 80-82% 83-84%
Fe2O3 MAX 4.5%max 2.80% 2.5-4% 5-7% 4.5% max
S1O2 Max 5.0%max 5.00% 3-6% 4-8% 6.0% max
TiO2 Max 4.5%max 4.00% 2-4% 3.5-4% 4.5%max
CaO MAX 2.5%max 2.00% 0.8-1.5% 0.8-1.2% 2.0-2.5%max
LOI MAX 0.50%max 0.50% 0.5-1 0.7-2.5% 0.5-3.1%GM/CC
B + D 3.1 GM/CC 3.15 GM/CC 3.29

TYPES OF CALCINED BAUXITE

Low Ferric ( 83 – 85 % Alumina / 3.0 % Fe2O3 )
Abbrasive Use ( 80-82 % Alumina / 4 % Fe2O3 / 1.5 % CaO)
BFA ( 83 – 85 % Alumina / 4 % Fe2O3 / 1.2 % CaO)
Refractory ( 83- 85 % Alumina / 3 % Fe2O3 )
General Grade ( 70-82 % Alumina / 4 % Fe2O3 )
Proppant Grade ( 78-82 % Alumina / 7 % Fe2O3 / 1.0 % CaO )
For Road Surfacing ( 78-82 % Alumina / 7 % Fe2O3 / 6.0 % SiO2 )
Rotary Kiln Calcined Bauxite ( 70-85 % Alumina / Bulk Density Minimum 3.0 gm/cc )
Shaft Kiln calcined Bauxite ( 70-85 % Alumina / Bulk Density Minimum 2.6 gm/cc )

calcined bauxite
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