Corundum Castables

Corundum refractory castables (also called corundum castables) is a high-grade granule refractory material, with an Al2O3 content of more than 90% and corundum as its main crystal phase.

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Introduction of Corundum Castables

Corundum refractory castables (also called corundum castables) is a high-grade granule refractory material, with Al2O3 content of more than 90% and corundum as its main crystal phase, which is widely used in high-temperature industries, such as kilns, tunnels, and furnaces. The main mineral phase of corundum castables is corundum (α-Al2O3), which has high advantages of high refractoriness, strong wear resistance, high structural strength, and good chemical stability. The raw material of corundum castables is fused white corundum or fused high alumina, or brown corundum. No matter what kind of raw material is used as aggregate, the different granularity of grains should be proportionally mixed, corundum coarse grains, middle grains, and powders should have proper formulation, then binders and additives (silica micro powder, water reducer, anti-explosion fiber) are added into the raw material and fully tempered.

Compared with high alumina castables and mullite castables, corundum castables have higher mechanical strength, wear resistance, high melting point, and strong slag erosion resistance. But its thermal shock resistance is not as good as mullite castables. When a proportional mullite component is added to the corundum castables, the thermal shock resistance of the corundum castables can be improved.

Packing of Corundum Castables

1. Plastic bag(25kg), Kraft bag (25 kg), Plastic bag(1 ton)

2. 1 ton on the pallet with plastic film

3. As per the customer’s request

Classification of Corundum Castables

1. Sub-white corundum: Sub-white corundum castables are made of calcined alumina or industrial alumina as raw material, melted at high temperature in an electric arc furnace, it is white, with large crystals, many pores, and the porosity is basically 6%-10%, The main crystal phase is alumina powder, the shape of the crystal is slender or rhombus, and the content of alumina is basically above 98.5%.

2. Brown corundum: Brown corundum castables is a kind of brown corundum material made by adding a small number of iron filings in an electric arc furnace at 2000°C. It is obtained by removing impurities from natural high-alumina combustion materials and carbon materials. The content of alumina is basically 94.5%-97%.

3. Special-grade high-bauxite bauxite clinker: The content of alumina is above 85%, and there are particles of different sizes. The high-temperature main crystal phase of high quality corundum castables is the corundum phase, with a small amount of mullite crystal and glass phase.

Application of Corundum Castables

1. Power generation industry, coal ditch, coal bucket, coal storage warehouse, dry coal gate, tipping machine, slag machine, water treatment.

2. Chemical industry's anti-corrosion ground, pump base, and so on.

3. Coal industry, media barrels, scraper, bucket machine, chute, sieve under the funnel, and other wear-resistant liners.

4. Steel industry, blast furnace mixing silo, feeder, the ball machine.

Properties of Corundum Castables

(1) The main raw material is tabular corundum with high density and melting point, which has excellent high-temperature performance.

(2) The high-temperature alkali resistance is good, and the alkali resistance level at 1350 °C can reach the second level or above, which solves the problem of poor alkali corrosion resistance of corundum castables.

(3) It has good thermal shock stability, avoiding the occurrence of peeling and falling blocks during the use of the product. This product is suitable for the front kiln fire hole and coal injection pipe of a large cement kiln.

Characteristics of Corundum Castables

High strength
High-temperature resistance
Strong wear resistance
Good erosion resistance
Excellent thermal shock stability

Chemical & Physical Index

Material		High-strength Corundum low cement refractory castables
Max working temp.(℃)		1650	1700	1750	1790
Bulk density after drying at 110℃, g/cm3		2.7	2.8	3	3.2
Chemical analysis, %	Al₂O₃≥	90	92	93	97
	CaO≤	2	2	2	1
	SiO₂≤	6	4	1	1
Cold bending strength (Mpa)	110℃*24H	13	13	8	7
Cold bending strength (Mpa)	1100℃*3H	15	15	80	80
Cold crushing strength	110℃*24H	100	100	80	90
(Mpa)	1100℃*3H	100	100	80	90
Linear change after heating, %	1350℃*3H	±0.60	±0.60	±0.50	±0.30
Water Addition		4.5-5.5%	5-6%	5.5-6.5%	5.5-6.5%
Construction method		Vibration	Vibration	Vibration	Vibration
Application		large scale cement kiln outlet, coal injection pipes, and other industrial furnace linings