High Alumina Raw Materials

High alumina raw materials (also called bauxite or flint clay) are used to improve the performance of refractories by imparting properties such as strength, protection from chemical and physical attack, and slag resistance.

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Introduction of High Alumina Raw Materials

High Alumina Raw Materials (also called bauxite or flint clay) are used to improve the performance of refractories by imparting properties such as strength, protection from chemical and physical attack, and slag resistance. Refractory products can be broadly divided into basic, neutral, and acidic groups, which relate to the type of refractory environment the product has been designed for (e.g., basic oxygen steelmaking) and hence the minerals used in its manufacture.

Minerals commonly used for refractories include (but are not limited to) alumina, bauxite, graphite, kaolin, magnesia, and zirconium. These minerals are produced globally but, in some cases, not always of grades suitable for refractory applications (e.g., magnesite and bauxite).

One of the most robust refractories is alumina, which consists of aluminum oxide and traces of other materials. Alumina is highly stable chemically and has superior hardness, strength, and spalling resistance. Refractory suppliers manufacture alumina that is suitable for lining furnaces operating at temperatures up to 1843 centigrade degrees.

The raw ores of alumina are mainly bauxite or flint clay, or mixed homogeneous materials.

Our calcined bauxite products have high alumina and low iron content, making them ideal refractory materials. We use our crushing and sizing technology to supply customers with the highest quality sized calcined bauxite and brown fused alumina. Quality is of the utmost importance and we are constantly aware that any deviation from our high standards could have major implications for refractory lining stability.

Features of High Alumina Raw Materials

High alumina bauxite, iron bauxite, industrial alumina, and clay as raw materials, which are made into mullite refractory bricks or High Alumina Bricks. The bauxite raw materials should be pre-fired to remove the structural water to avoid popping and splashing when the electric arc is concentrated and decomposed in the electric arc furnace.

Production Procedure of High Alumina Raw Materials

1. The production procedure of a refractory brick is divided into raw material selection, calcining, forming, crushing, batching, mixing, placing material, molding, drying, burning, assessment, and packing.

2. The rate of refractory brick and raw material price, physical and chemical index, and production procedure are quickly specified.

3. Raw material choice, beneficiation, and purification, High-purity raw materials are the premise for producing high-quality refractories.

4. Calcining, except for some raw materials, most of the raw materials utilized as refractory aggregate must be calcined at great temperatures.

5. A series of physical and chemical reactions are generated when the raw material is calcined, which plays a vital role in enhancing the composition, increasing mineral composition and structure of the refractories, and assuring the volume stability of the refractory and the precision of the apparent size.

6. The indexes of material sintering contain apparent porosity, bulk density, water absorption, etc.

7. Sorting, crushing, and proportioning the raw material requires to be screened after crushing and grinding, because the semi-finished material is graded by various sizes of powder, and ensures received a dense body with a greatly compact.

8. Each variety of equipment can generate various fineness of finished powder by grinding, 80 mesh -425 mesh, 500 mesh -2000 mesh, and the finest can achieve about 2500 mesh.

9. Mixing, and placing material, in order to homogenate the components and particles of raw meal and clinker, It is essential to mix and add binder at a similar time to improve the bonding strength of the semi-finished material.

10. After molding, drying, and pressing by great pressing equipment and molded, the green refractory bricks should be placed for a particular time to dry.

11. Burning, the complete product was sintered by high-temperature sintering at a high-temperature kiln.

12. Checking and packing.

Application of High Alumina Raw Materials

To be made into refractory products, such as refractory bricks, refractory castables, refractory mortars, etc.

Package of High Alumina Raw Materials

1. In 1MT Big Bag

2. 25KG PP Bag packed In 1MT Big Bag

3. Customized packing as required

Physical Parameters

Color	White, gray, sometimes stained yellow, orange, red, pink, or brown by iron or included iron minerals
Streak	Usually white, but iron stains can discolor
Luster	Dull, earthy
Diaphaneity	Opaque
Cleavage	None
Mohs Hardness	1 to 3
Specific Gravity	2 to 2.5
Diagnostic Properties	Soft, low specific gravity, color. Often exhibits pisolitic habit.
Chemical Composition	Variable but always rich in aluminum oxides and aluminum hydroxides
Crystal System	n/a
Uses	The primary ore of aluminum. Synthetic bauxite is used as an abrasive and as a fracking proppant.

Chemical Parameters

Grades	Al₂O₃（%）	Fe₂O₃ (%)	Ti₂O（%）	CaO+MgO（%）	K2O+Na₂O（%）	Bulk Density (g/cm³)	Water Absorption (%）	Refractoriness (℃)
90	≥90	≤1.4	≤2.5	≤0.2	≤0.2	≥3.4	≤3	1910
87	≥87	≤1.8	≤3.1	≤0.2	≤0.2	≥3.2	≤3	1850
85	≥85	≤1.9	≤3.2	≤0.2	≤0.2	≥3.1	≤4	1800
80	≥80	≤2.0	≤3.5	≤0.3	≤0.3	≥2.9	≤5	1750
70	70-80	≤2.0	≤3.8	≤0.6	≤0.6	≥2.75	≤5	1710
60	65-70	≤2.0	-	≤0.6	≤0.6	≥2.45	≤6	1650
50	55-65	≤2.2	-	≤0.6	≤0.6	≥2.45	≤6	1610
45	45-55	≤2.5	-	≤0.6	≤0.6	≥2.40	≤7	1550