Chemical / Cement Grade Bauxite is a non-metallurgical grade of bauxite used primarily as a raw material or additive in chemical manufacturing and cement production, rather than for aluminium metal extraction.
Unlike metallurgical grade bauxite, which demands very high alumina and low reactive silica, chemical and cement grades are selected for their chemical reactivity, thermal behavior, and fluxing properties.
Key distinction:
✔ Metallurgical bauxite → aluminium metal
✔ Chemical / Cement grade bauxite → chemical reactions & cement performance
Mineralogical & Chemical Behavior
✔ High chemical reactivity under heat
✔ Releases chemically bound water during calcination (dehydroxylation)
✔ Forms reactive alumina phases
✔ Acts as an alumina source and flux regulator in kiln and reactor systems
These characteristics make chemical and cement grade bauxite ideal for controlled kiln, furnace, and chemical reactor environments.
Processing & Refining Characteristics
| Process Step | Description |
|---|---|
| Crushing & Screening | Particle size control for blending |
| Drying / Calcination | Partial or full thermal activation |
| Blending | Mixed with limestone, clay, gypsum, or additives |
| Final Use | Chemical reactors or cement kilns |
✔ No Bayer process required
✔ No aluminium smelting involved
✔ Lower energy and processing cost than metallurgical bauxite
Applications
1. Chemical Industry
Used as a feedstock for:
✔ Aluminium sulfate (alum) – water treatment, paper industry
✔ Polyaluminium chloride (PAC) – wastewater treatment
✔ Aluminium chloride
✔ Catalyst supports
✔ Adsorbents & desiccants
✔ Flame retardant fillers
2. Cement Industry
Used as:
✔ Alumina corrective material in clinker production
✔ Raw material for high-alumina cement (HAC)
✔ Component in specialty & refractory cements
Cement Performance Benefits
✔ Controls setting time
✔ Improves early strength
✔ Enhances sulfate resistance
✔ Improves kiln efficiency
3. Refractory & Construction Additives (Secondary)
✔ Low-grade refractory bricks
✔ Heat-resistant mortars
✔ Construction chemicals
Available Forms
✔ Run-of-Mine (ROM) bauxite
✔ Crushed & sized bauxite
✔ Powdered / ground bauxite
✔ Calcined chemical grade bauxite
✔ Blended raw meal (cement plants)
Advantages of Chemical / Cement Grade Bauxite
✔ Lower cost than metallurgical bauxite
✔ High chemical reactivity
✔ Flexible composition tolerance
✔ Simple processing route
✔ Ideal alumina source for non-metal applications
✔ Supports large-volume industries (cement, water treatment)
Why Choose Chemical / Cement Grade Bauxite?
For Chemical Manufacturers
✔ Reliable alumina input
✔ Stable reaction behavior
✔ Cost-effective raw material
✔ Consistent product quality
For Cement Producers
✔ Efficient alumina correction
✔ Improved clinker mineralogy
✔ Reduced dependency on expensive additives
✔ Better control over cement performance
For Infrastructure & Utilities
✔ Enables water purification chemicals
✔ Supports durable and sustainable construction materials
Chemical / Cement Grade vs Metallurgical Grade
| Aspect | Chemical / Cement Grade | Metallurgical Grade |
|---|---|---|
| Primary Use | Chemicals & Cement | Aluminium Metal |
| Al₂O₃ Requirement | Medium | High |
| Reactive Silica | Tolerable | Must be Low |
| Processing | Simple | Complex (Bayer) |
| Cost | Lower | Higher |
| Energy Use | Low | High |
Chemical / Cement Grade Bauxite is a workhorse industrial mineral. While it does not produce aluminium metal, it is critical to water treatment, cement manufacturing, construction chemistry, and large-scale industrial processing.
Its chemical reactivity, thermal behavior, cost efficiency, and availability make it indispensable for high-volume, non-metallurgical applications.