CrO Content % International Standard Alumina Block Hollow Ball Bricks for Glass Furnace

 Description of aluminum hollow ball bricks

Alumina hollow ball brick is a new kind of high temperature heat insulation material, which is made by smelting and blowing of industrial alumina in electric furnace.In alumina hollow ball as the main body, can be made into various shapes, the highest temperature 1800 ℃, high mechanical strength, general light products several times, and the bulk density is only half of the corundum products.It has been widely used in high temperature and ultra-high temperature kilns such as petrochemical gasifier, carbon black industrial reaction furnace and induction furnace in metallurgical industry.

Detailed production steps for aluminum hollow ball bricks
The preparation method of the alumina hollow spheres is a ball burning loss method and a melt blowing method. The rolling ball method is to first make a core pill with an organic resin or a low-melting material, put it in a rotating disc, and then sprinkle the moist alumina fine powder containing a certain amount of water on the disc, and adhere it to the core pill to form A shell is like a icing on the outside of a pill. The pellets are then fired at a high temperature, in which the core pellets are burned out and the shell is sintered to form a hollow sphere. The disadvantage of this method is that it is inefficient, the spherical surface is not smooth, and the wall thickness and size are not easy to control, so it is not used much in industrial production.
Industrial Al2O3 is used as a raw material and directly melted in an electric arc furnace. The electric arc furnace can be used in single-phase or three-phase, and three-phase is preferred. The furnace body is provided with a tilting device, and the discharge port is provided with a gas nozzle at an angle thereto. The furnace lining material is graphite. Assuming that the furnace diameter is 550 mm, the furnace height is 300 mm, the graphite electrode diameter is 150 mm, and the electrode radius is 150 mm, the melting voltage is 100 V and the current is 1500 to 1700 A. During the melting process, the alumina fine powder is gradually and intermittently added until the melt reaches a sufficient amount to stop the feeding. When the material is completely melted, the viscosity of the melt is appropriate. When the temperature of the melt is about 2200~2300 °C, the furnace body can be tilted to make the melt flow out from the discharge tank, and the pneumatic valve is opened at the same time, and the exhaust gas volume is 10 m3/min. Compressed air with a pressure of 0.6~0.8MPa blows the liquid into droplets. The droplets solidify rapidly in the air due to melt viscosity and surface tension, forming a shell-shaped sphere. Go to the collection room. After sorting, sieving or rinsing, the frit fragments, and the large spheres and small spheres with a particle diameter greater than 5 mm or less than 0.2 mm are removed, and the qualified hollow spheres of 5 mm to 0.2 mm are classified according to the particle size.
The natural bulk density of the alumina hollow sphere is 0.42~0.97g/cm3, and the perfect rate of the blowing ball is 70%~90%. As the ball diameter decreases, the ball's integrity rate increases and the ball's natural bulk density increases. The hollow spheres have an alumina content greater than 99.5%. This hollow sphere can be used directly as a bulk insulation material. When used, the size of the ball can be matched, and the appropriate amount of light-burning α-Al2O3 fine powder is mixed, so that the thermal insulation effect is better. Alumina hollow spheres can be used up to 1800 °C.
If a hollow sphere is used as the aggregate, the alumina fine powder is used as the base material, and the aluminum sulfate and the carboxymethyl cellulose solution are used as the binder to form the hollow spherical brick. The hollow balls are appropriately sized. The alumina fine powder is α-Al2O3 obtained by calcining, pulverizing and purifying the industrial γ-AI2O3 at 1450 ° C, and the amount of Al 2 O 3 is more than 99%, and the particle size is less than 0.147 mm, of which about 85% is less than 5 μm. The binder was added in an amount of 5% aluminum sulfate solution (20% by mass) and 4% carboxymethylcellulose solution (mass fraction 3%). The mixed billet is poured into a wooden mold and placed on a vibrating table to be gently pressed and molded to obtain a complete and uniformly distributed green body. After the green body is dried, it can be fired at different temperatures of 1500~1800 °C according to different application requirements. The product has a porosity of 50% to 70%, a compressive strength of 4 to 6 MPa, and a thermal conductivity of 3.3 to 3.8 kJ/m·h·°C. The thermal shock cycle of 1100 ° C ~ air-cooled is more than 15 times. It is a kind of fire-resistant and heat-insulating material with both strength and good heat insulation. The performance of the product varies greatly with the amount of alumina fine powder added and the firing temperature. The change of the size ratio of the ball has little effect on the performance of the product.

High temperature refractory aluminum hollow ball bricks

aluminum hollow ball bricks physical and chemical index

Advantages of aluminum hollow ball bricks?
aluminum hollow ball bricks are made of alumina hollow spheres and alumina powder as the main raw materials, combined with other binders, and fired at a high temperature of 1750 degrees. It is a kind of energy-saving insulation material for ultra-high temperature materials.

It will achieve obvious results in reducing the weight of the furnace, transforming the structure, saving materials and saving energy.

1, the use of high temperature:

It can reach more than 1750 degrees and has good thermal stability. The reburning line has a small rate of change and is used for a longer period of time.

2. Optimize the structure and reduce the weight of the furnace:

Now the high temperature resistant materials are all heavy bricks with a bulk density of 2.6-3.0g/cm, while aluminum hollow ball bricks are only 1.1~1.5g/cm, the same cubic meter volume, using aluminum hollow ball bricks can reduce 1.1- 1.9 tons of weight.

3. Saving materials:

To achieve the same temperature of use, such as the use of heavy bricks, the price is comparable to the price of aluminum hollow ball bricks, and also requires considerable insulation refractories. If you use aluminum hollow ball bricks, you can save 1.1-1.9 tons of heavy bricks per cubic meter, and save 80% of refractory insulation materials.

4. Save energy:

The alumina hollow sphere has obvious heat preservation characteristics and low thermal conductivity, which can play a good thermal insulation effect, reduce heat dissipation and improve thermal efficiency, thereby saving energy. Energy saving effect can reach more than 30%.

Alumina hollow spheres and their products are lightweight refractories with excellent high temperature and energy saving, and are very stable in various atmospheres. Especially applied on high temperature kiln at 1800 °C. Hollow balls can be used for high temperature, ultra high temperature insulation fillers, high temperature refractory concrete lightweight aggregates, high temperature castables, etc. Hollow ball bricks can be used for high temperature energy saving (>30%) downdraft kiln, shuttle kiln, molybdenum wire furnace, tungsten rod furnace, induction furnace, nitriding furnace, etc. It will achieve obvious results in reducing the weight of the furnace, transforming the structure, saving materials and saving energy.

Α-alumina powder is made of high-quality industrial alumina. It is produced by a new high-temperature inverted kiln and scientific calcination process. It is manually selected, with clear classification, less impurities, high conversion rate, stable shrinkage and good consistency. .

Workshop corner

 Packaging of aluminum hollow ball bricks

 Shipping of aluminum hollow ball bricks

1.Our packaging is as per customer’s request
2.Normal goods delivered by sea transport
3.Sample shipping by express
4.We will shipping and delivery goods timely, quanlity and quantity guaranteed, and also in accordance with the contract and customer's requirment completely.

1. Strong professional:

Our company has thirty years producing experience in refractory product. Our manager will supervise on a various refractory' s production materials, process control, quality supervision and package delivery, and ensure the products are 100% qualified.
2. Annual exports:
Now we have gained a global sales network reaching Taiwan, Russia, Mongolia, South Korea, Vietnam, Pakistan, Bulgaria, Finland, Greece, Spain, Congo, Angola, South Africa, and Maldives, Jordan and so on. The export figure is more than USD 4 million.
3. Production equipment:
Production and testing equipments are new, complete and automated or semi- automated. Such modern facilities and equipments have provided the fine technical guarantee for the production and testing.
4. Testing equipment:
Our company's testing equipments as follows:
High Temperature RUL Tester
Bulk Density Tester
The Pressure Tester
Refractoriness Tester

Certificates