Calcined Zone Cement Kiln High Strength Brick for 1250-1400 Refractoriness Under Load

Description of  Alkali refractory brick
The Alkali refractory brick for cement kiln refers to a clay refractory brick which is made of low-aluminum refractory clay as the main raw material and has alkali corrosion resistance in the cement kiln system. The main raw materials used in Alkali refractory bricks are coke gems, pyrophyllite, silica and the like.

The alkali-resistant mechanism of Alkali refractory bricks is that they react with alkali metal oxides at high temperatures to form a high-viscosity liquid phase, forming a glazed protective layer covering the surface of the bricks to block surface pores to prevent alkali metal melts. The penetration and erosion play the role of alkali corrosion resistance.

The Alkali refractory brick is a semi-silica refractory material having an Al2O3 content of 25% to 30%. It is made of low-aluminum refractory clay as the main raw material. Due to its chemical composition, it can form a certain thickness of alkali-resistant protective layer on its surface, so it has wide application in cement precalcining furnace system.

Why use Alkali refractory bricks in cement kilns?

In the production of rotary kilns, harmful components such as alkali, sulfur, chlorine and other harmful components from the original, burning, and so on, in the high-temperature zone, form sulphate and chlorinated alkali and escape with the kiln gas, in addition to the corrosion of alkaline bricks in the burning zone and transition zone. In addition to the damage, the kiln tail smoke chamber, differentiation furnace, preheater, etc. are condensed and enriched due to the drop in temperature, which can penetrate into the ordinary clay bricks and react with the brick body, generating swelling minerals, causing the clay bricks to crack and fall off. Damaged by alkali cracking.

Alkali refractory bricks are semi-silica refractory materials with Al2O3 content of 25% to 30%. It is made of low-aluminum refractory clay as the main raw material. Because of its chemical composition, it can form a certain thickness of alkali-resistant protective layer on its surface, so it is widely used in cement pre-differentiation kiln systems.

Application of Alkali refractory bricks in cement kiln

Alkali refractory bricks: refers to low-aluminum refractory clay, silica, coke stones, waste porcelain and appropriate additives as the main raw materials. The product has the characteristics of stable volume, strong alkali corrosion resistance and penetration resistance. Used for preheater, calciner, tertiary duct and other parts of cement kiln

Ordinary type Alkali refractory brick : Mainly used in cement kiln preheaters, decomposition furnaces, and other air ducts.
High-strength Alkali refractory brick : Mainly used in cement kiln preheaters, decomposing furnaces, tertiary air ducts, vertical ascending flue, cyclone straight tubes and cones.
The arch-type Alkali refractory brick : Mainly used for the cement kiln preheater and the tertiary air duct of the decomposition furnace.
The heat-insulating Alkali refractory brick : Mainly used for the kiln mouth, kiln door cover and cooling machine of the cement kiln.

How to choose refractory materials for various parts of cement kiln 

1.Pre-tropical zone and decomposition zone
The temperature of these two places is relatively low, and the thermal conductivity of the brick lining is required to be small, and the wear resistance is good. In this area, the alkali metal and the chlorinated alkali from the raw materials and fuels begin to volatilize, condense and enrich in the kiln, and penetrate into the brick. internal. Ordinary clay bricks react with alkali to form potassium nepheline and leucite, which makes the brick surface crisp, and the brick body expands and causes cracking and peeling. When the Alkali refractory brick or alkali-resistant heat-insulating brick containing Al2O325%~28% and SiO265%-70% reacts with alkali at a certain temperature, the surface of the brick immediately forms a high-viscosity glaze layer to prevent peeling. But this brick can't resist the use temperature above 1200 degrees Celsius. Therefore, the pre-tropical zone generally uses phosphate combined with high alumina bricks, anti-flaking high alumina bricks or alkali resistant bricks.
The decomposition zone generally adopts high-aluminum bricks with good anti-flaking properties. The silica-based bricks are superior in performance to the high-alumina bricks with good peeling resistance. The service life is about twice as high as that of the anti-flaking high-aluminum bricks, but the price is higher. Anti-skinning silicon carbide castables should be used for the tail feed.
2. Transition zone and firing zone
The transition zone kiln skin is unstable, and the kiln lining is required to resist the change of atmosphere, good thermal shock resistance, small thermal conductivity and wear resistance. Magnesium-aluminum spinel bricks are recommended in foreign countries, but the thermal conductivity of the bricks is large, the cylinder temperature is high, and the relative heat consumption is large, which is not conducive to reducing energy consumption. Domestic silicon molybdenum has a small thermal conductivity and wear resistance, and its performance is comparable to imported materials to a certain extent.
The firing zone has a high temperature and a strong chemical reaction. It requires brick lining to resist clinker erosion and strong resistance to SO3 and CO2. Magnesium-aluminum spinel bricks are generally used abroad, but the brick-hanging kiln skin is more difficult, and the dolomite bricks are not resistant to thermal shock and easy to hydrate; the foreign magnesium-iron spinel bricks have better effect on the hanging kiln skin. But the cost is too high. The newly used low chromium periclase composite spinel bricks in China are in good condition.
3. Cooling belt and kiln mouth
The temperature at the cooling zone and the kiln mouth is as high as 1400 degrees Celsius, the temperature fluctuates greatly, and the grinding of the clinker and the flushing of the airflow are serious. The brick lining is required to have small thermal conductivity, good wear resistance and thermal shock resistance; alkaline bricks excellent in thermal shock resistance, such as spinel bricks or high alumina bricks, are suitable for use in the cooling zone. Spinel bricks are generally recommended in foreign countries, but the spinel bricks have a high thermal conductivity and poor wear resistance. In recent years, most of the domestic use of silicon bricks and wear-resistant bricks with good peeling resistance.
The kiln mouth part is mostly made of castable material with good thermal shock resistance. For example, high-aluminum brick or steel fiber-toughened castables and low-cement high-aluminum castables that are resistant to thermal shock, but are used in large kiln with extremely high kiln temperature, using ordinary or steel fiber toughened corundum. Casting material.

 Packaging of refractory bricks

 Shipping of refractory 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. How can I get your prompt quotation?

   We can give you reply with quotation quickly if you kindly send the inquiry with the detail, such as the quantity, the specifications and the application of the products.

2. What is the MOQ (minimum order quantity)?

   No limit

3. Which payment terms can you accept?

   T/T,LC,Western Union,moneygram are available for us. 

4. After an order is placed, when to deliver?

   15-25days after confirming the order.

5. Does your company accept customization?

   We accept OEM service.

6. How to solve the quality problems?

   If the products don't conform to customer's samples or have quality problems, our company will be responsible to make compensation for it based on enough evidences.

1. Strong professional:
Our company has thirty years producing experience in refractory products. Our manager will supervise on a various refractorys production materials, process control, quality supervision and package delivery, and ensure the products are 100% qualified.

2.Annual supply:
Our company has passed ISO9001 quality management system certification and SGS certification. And the annual supply of shaped and unshaped refractory product is 28, 800-35, 000 tons.

3. Export experiences:
Now we have gained a global sales network reaching Taiwan, Russia, Vietnam, Pakistan, Bulgaria, French, India, Congo, Angola, South Africa, and so on.

4. 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.

5. Testing equipment:
Our company's testing equipments as follows:
High Temperature RUL Tester
Bulk Density Tester
The Pressure Tester
Refractoriness Tester

Certificates

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