Refractory Bricks

Features Of High Alumina Refractories

Mar 31,2017
Aluminium Oxide (Al2O3 ) or alumina is one of the most versatile of refractory ceramic oxides and finds use in a wide range of applications. High alumina refractories are alumina refractories containing more than 45% alumina.

High alumina bricks is made of high-quality bauxite chamotte as raw materials by shaping at high pressure and sintering at high temperature. Alumina is one of the most chemically stable oxides known, which offers excellent hardness, strength and spalling resistance, which imparts high alumina refractories great features.

The alumina content ranges from 45 to 100%. The refractoriness of high alumina refractories increases with increase of alumina content. So high alumina refractories have high refractoriness and excellent high temperature performance.

High alumina refractories are a kind of acid refractories. Therefore, they have good resistance to acid slags. High alumina refractories are also featured with high cold crushing strength. As the alumina content increases, the cold crushing strength also increases. This makes them to bear more load during use. The high hardness of alumina imparts high wear and abrasion resistance.

Manufacturing cost and price of these brick increase more rapidly with alumina content, so it is essential to determine experimentally or by test installations the most economical alumina content for each service. In some areas such as the regenerators, fire clay bricks can be used as a replacement for high alumina refractories.

Due to severe service conditions prevailing in modern reheating furnaces, there is an increasing tendency to use more and more of high alumina bricks in place of conventional fire clay bricks. The applications of high alumina refractories includes the hearth and shaft of blast furnaces, ceramic kilns, cement kilns, glass tanks and crucibles for melting a wide range of metals.

Here are the Features and Application about some high alumina refractory prouducts:

Item

Name

Features &Application

Physical and chemical indicators

1

Fire clay brick

1.Specification:Standard&special shape;
2.Good thermal shock resistance;
3.Used for various furnace;
4.The cheapest price.

1.Al2O3:30-48%;
2.Refractoriness:1580-1750C;
3.Refractoriness under load:1300-1400C;
4.Bulk density:2.0-2.2g/cm3.

2

Low porosity
fire clay brick

1.Specification:Standard&special shape;
2.High pressure forming and high temperature sintering;
3.Low porosity,high density;
4.Used for the middle and lower position
of the regenerator in glass furnace.

1.Al2O3:41-45%;
2.Refractoriness:1750C;
3.Refractoriness under load:>1500C;
4.Bulk density:2.3-2.37g/cm3.

3

High alumina
fire brick

1.Specification:Standard&special shape;
2.Sintering process maked;
3.Good thermal stability;
4.Used for the important position in furnace;

1.Al2O3:48-80%;
2.Refractoriness:1790C;
3.Refractoriness under load:1300-1400C;
4.Bulk density:2.3-2.65g/cm3.

4

Kaolin tank
furnace big block

1.Specification:Standard&special shape;
2.Vacuum pouring craft;
3.The internal structure is uniform and stable;
4.Used for the pool bottom and pool wall of
furnace.

1.Al2O3:38-43%;
2.Refractoriness:1750C;
3.Refractoriness under load:1400-1450C;
4.Bulk density:2.2-2.3g/cm3.

5

Silica firebrick

1.Specification:Standard&special shape;
2.Well resist acid slag erosion;
3.Refractoriness under load is close to refractoriness ;
4.Nondeformable under high temperature using;
5.Used for masonry coke oven furnace body,the regenerator and slag chamber of the open hearth furnace,glass furnace,hot blast stove etc.

1.SiO2:95-96%;
2.Refractoriness:1710C;
3.Refractoriness under load:1650-1680C;
4.Bulk density:1.85-1.9g/cm3.

6

Fused azs
fire brick

1.Specification:Standard&special shape;
2.Brand No.;AZS33#;AZS36#;AZS41#;
3.Process:Melting,casting;annealing;
4.Good corrosion resistance,long-use life;
5.Used for the most important position of glass furnace.

1.Al2O3:40-50%;
2.ZrO2:32-41%;
3.SiO2:13-17%;
4.Exudation temperature of glass phase:
1080-1400C;
5.Refractoriness under load:1400-1450C;
6.Bulk density:3.4-3.95g/cm3

7

Sintered azs
refractory brick

1.Specification:Standard&special shape;
2.Good resistance to glass liquid erosion;
3.Good thermal shock resistance;
4.Used for pool bottom,hanging wall,breast wall,
small furnace,regenerator checker,side wall.

1.ZrO2:18-30%;
2.Al2O3:48-70%;
2.Refractoriness:1770-1790C;
3.Refractoriness under load:1600-1680C;
4.Bulk density:2.8-3.4g/cm3


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