Silica Bricks

Why Choose Us?

Professional team
After more than 20 years of development and experience accumulation. Our union has strong research and development capability, R&D centre is full responsible for test, research and product innovation, with 31 senior engineers, 96 engineers and 179 assistant engineers.

Complete range of products
We produce and operate refractory raw materials, refractory products, ceramic products, graphite electrodes, refractory binders, wear-resistant, acid-resistant and heat-resistant products, special building materials, silicon carbide products, refractory equipment, molds, copper molds, copper tubes, copper plates, Stainless steel products, slag pot, etc., including import and export. Imported calcium stabilized zirconia, yttria stabilized zirconia, quartz sand, graphite, andalusite, zirconium corundum etc.

High quality service
Zibo runjin has been persisting in a service philosophy of "Customers's Satisfaction is our eternal pursuit", taken "building a Worldwide first -class refractory manufactures" as the mission, and held "co-creation, co-operation, co-prograss, win-win"as its core values.Relying on management and technology accumulation during past many years, based on its over many years reputation as guarantee. Zibo runjin is doing its best to offer refractory system solutions with values added to achieve co-progress with our customers.

Advanced equipment
There are five high-quality clay high alumina brick production lines, two production lines for andalusite brick and mullite brick, five silica brick production lines, three production lines for continuous casting, One carbon and silicon carbide composite refractory production line ,One production line for tundish stabilizer, impact plate and slag retaining wall, a production line for high-grade light products, Pure oxide refractory production line, Unshaped refractory production line, Non-fired brick refractory product production line.

What Are Silica Bricks

Silica is a refractory ceramic which is widely used in the steel and glass industries. Silica bricks are prepared by kiln-firing quartz of low impurity content at a temperature of 1450°C, thereby converting at least 98.5% of it into a mixture of the more 'open', less dense forms, tridymite and cristobalite.

Silica Bricks for Coke Oven

The volume of high-alumina continues to expand, and coke ovens are developing into large-scale. The

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Silica Bricks for Hot Blast Stove

With the development of modern blast furnace smelting technology, high air temperature and high air

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Silica Brick for Glass Furnace

Silica brick for glass melting furnace refers to siliceous refractory products used for building

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Silica Insulating Bricks

Also known as Silica Insulation Brick. Lightweight refractory with a silica content of more than

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Silica Brick Production Technology

For the production of silica bricks, in addition to paying attention to the principle of closest packing, the influence of mixing process, molding pressure, firing conditions and other aspects should also be fully considered.
The production process of silica bricks typically involves the following steps:

01/

Raw Material Preparation: The first step is to select high-quality raw materials, typically silica-rich materials such as quartzite, silica sand, or ganister. The raw materials are crushed and ground to obtain a fine and uniform particle size distribution.

02/

Mixing: The crushed and ground raw materials are thoroughly mixed with water or a binder to form a plastic or semi-plastic mass. This step ensures that the raw materials are evenly distributed and well bonded.

03/

Molding: The plastic or semi-plastic mass is then shaped into bricks using various molding techniques such as extrusion, pressing, or casting. The bricks can be formed in different shapes and sizes depending on the desired application.

04/

Drying: The molded bricks are dried to remove excess moisture and improve their strength. This is typically done by air drying or using a drying oven. Care must be taken to control the drying process to prevent cracking or deformation.

05/

Firing: The dried bricks are subjected to a high-temperature firing process known as sintering. The firing temperature for silica bricks is usually around 1450-1600°C (2642-2912°F). The bricks are loaded into kilns or furnaces, and the temperature is gradually increased to allow for proper heat distribution and controlled expansion. The firing process helps to fuse the raw materials together and transform them into a dense and stable structure.

06/

Cooling and Testing: After the firing process, the kiln or furnace is allowed to cool down slowly to room temperature. The cooled silica bricks are then tested for various properties such as density, porosity, strength, and thermal conductivity to ensure they meet the desired specifications.

Silica Brick - Physical Properties

Acid-base resistance
Silica brick is an acidic refractory material, which has strong resistance to acidic slag erosion, but when it is strongly corroded by alkaline slag, it is easily damaged by oxides such as AI2O3, and has good resistance to oxides such as CaO, FeO, and Fe2O3.

Expansibility
The thermal conductivity of silica bricks increases with the increase of working temperature, without residual shrinkage. During the oven process, the volume of silica bricks increases with the increase of temperature. In the oven process, the maximum expansion of silica brick occurs between 100 and 300 ℃, and the expansion before 300 ℃ is about 70% to 75% of the total expansion. The reason is that SiO2 has four crystal form transformation points of 117℃, 163℃, 180~270℃ and 573℃ in the oven process. Among them, the volume expansion caused by cristobalite is the largest between 180~270℃.

Deformation temperature under load
The higher deformation temperature under load is the advantage of silica bricks, which is close to the melting point of tridymite and cristobalite, which is between 1640 and 1680°C.

Thermal stability
The key to determining the thermal stability of silica bricks is the density, and the density is one of the important signs to determine its quartz conversion. The lower the density of the silica brick, the more complete the lime conversion and the smaller the residual expansion during the oven process.

Refractory Silica Brick

● Silica fire brick is an acid-refractory material, with good resistance to acid slag erosion, and load softening temperature of up to 1640 ~ 1670 ℃, the volume of long-term use at high temperatures is relatively stable.

● It is mainly used in the partition wall of the charring room and combustion room of the coke oven, the heat storage room and slagging room of the steel-making flat furnace, equalization furnace, refractory material of the glass melting kiln and ceramic firing kiln, etc., and other load-bearing parts of the kiln's vaults and so on. It is also used in the high-temperature load-bearing part of hot blast furnaces and the roof of acid-flat furnaces.

● It is mainly acidic refractory material composed of scaled quartz, square quartz, and a small amount of residual quartz and glass phase. Silicon dioxide content of 94% or more. True density 2.35g/cm3.
Resistant to acidic slag erosion. Higher high-temperature strength. Load softening start temperature 1620～1670℃. No deformation under high temperature for long-term use. Low thermal shock stability (heat exchange in water is 1~4 times).
Natural silica as raw material, plus an appropriate amount of mineralizing agent, to promote the transformation of quartz in the body of the blank to, scale quartz. Slowly fired under reducing atmosphere by 1350 ~ 1430 ℃.
Heating to 1450 ℃ about 1.5 ~ 2.2% of the total volume expansion, this residual expansion will cut joints close, to ensure that the masonry body has good airtightness and structural strength.
Scalar quartz, argillaceous quartz, and residual quartz have large changes in volume at low temperatures due to changes in crystal type, so the thermal stability of silica bricks at low temperatures is poor.
During use, it should be heated and cooled slowly below 800℃ to avoid cracks. Therefore, should not be used in 800 ℃ below the temperature of the rapid change in the kiln.

● The nature and process of silica bricks are closely related to the crystalline transformation of SiO2. Therefore, the true specific gravity is an important quality indicator of silica bricks.
General requirements in 2.38 or less, high-quality silica refractory bricks should be 2.35 or less. True specific gravity is small, reflecting the brick in the number of scale quartz and square quartz, residual quartz amount is small, so the residual linear expansion is small, and the use of strength decline is also less.
Silicon dioxide has seven crystalline variants and one amorphous variant. These variants can be divided into two categories: the first type of variant is quartz, quartz, and quartz, their crystalline structure is very different, and the transformation between each other is very slow. The second type of variant is a subspecies of the above variants — α β and γ type, their structure is similar, and the transformation between each other is faster.

● The raw material for the manufacture of silica bricks is silica. In Silica raw materials, the higher the SiO2 content, the higher the refractoriness. The most harmful impurities are Al2O3, K2O, Na2O, etc., they seriously reduce the refractoriness of refractory products.
Silica bricks are made from silica with SiO2 content of not less than 96%, adding mineralizing agent (e.g., iron scale, milk of lime) and binding agent (e.g., molasses, sulfite pulp waste liquid), and produced by mixing, molding, drying, and sintering processes.

Applications of Silica Brick

Silica brick finds extensive applications in various industries, particularly those involving high temperatures and acidic environments. Common applications include:

Glass Industry

Silica brick is the primary material for lining glass furnaces, particularly in the regenerator chambers, where it withstands the high temperatures and corrosive action of molten glass.

Coke Ovens

Silica brick is used in coke ovens to construct the coking chambers, where it resists the high temperatures and acidic gases generated during the coking process.

Ceramic Industry

Silica brick is employed in ceramic kilns, particularly in the firing chambers, where it withstands the intense heat and chemical reactions involved in ceramic firing.

Steel Industry

Silica brick is used in steelmaking furnaces, particularly in the lining of regenerators and ladles, where it resists the harsh environment of molten steel and slags.

Non-Ferrous Metal Furnaces

Silica brick is used in furnaces for the production of non-ferrous metals, such as copper, lead, and zinc, where it withstands the high temperatures and acidic fumes generated during the smelting process.

Incinerators

Silica brick is used in incinerators to line the combustion chambers and flue gas systems, where it resists the aggressive environment of high temperatures, toxic gases, and abrasive particles.

Our Factory

After more than 20 years of development and experience accumulation, The main production plants of Runjin technology and trade complex are as follows:
Qingdao Huaye New Material co., ltd.
Shandong Daqiao New Material co., Ltd.
Yangquan Wanglong Refarctories co.Ltd.
Anshan Aoan High Temperature Material Co., Ltd.
It's total assets value has reached 1.05 Billion RMB and currently employs 4078 personnel, including 544 refractory technical personnel and 3145 well trained workers
The annual production capacity has exceeded 30 thousands tons with comprehensive seven series refractories as following: Fire clay bricks, Alumina bricks, Con-casting refractory, Binder for refractory, Fine Ceramics, Graphite electrode, acid resistant brick, Silicon carbon crucible, Silicon carbon plate, Special building material, Cellulose ether, Super chamotte raw material and Synthesized mullite material, Magnesia raw material, etc. Products are applied to worldwide industries of metallurgy, building material, non-ferrous metal smelting, petrochemical, nonferrous, electronics, cement industry and so on. Approx. 68% products are supplied to metallurgy industry. China leading Steel group.-e.g.Baowu steel, Anshan steel, WISCO, SHOUGANG, TISCO, PANGANG, HBIS, SHAGANG, which belongs to same parent company are our main customers in domestic market.in oversea market, Zibo runjin is a refractory supplied of Arcelor - mittal, POSCO Guangyang steel, HYUNDAI steel, Nippon steel, JFE steel, US United Steel, Erdemir group., Danieli, SVAI and working together with famous refractory manufactures -e.g.Chosun refractories, ANH refractories and Krosaki refractories etc. Zibo runjin also has a good cooperation with world famous engineering companies .
our union has strong research and development capability, R&D centre is full responsible for test, research and product innovation, with 31 senior engineers, 96 engineers and 179 assistant engineers. Zibo runjin enables itself to be one of then leading refractory manufactures for supplying andalusite bricks for CDQ furnace, silicon bricks, AG con-casting refractory and so.
Zibo runjin has been persisting in a service philosophy of "Customers's Satisfaction is our eternal pursuit", taken "building a Worldwide first -class refractory manufactures" as the mission, and held "co-creation, co-operation, co-prograss, win-win"as its core values.Relying on management and technology accumulation during past many years, based on its over many years reputation as guarantee. Zibo runjin is doing its best to offer refractory system solutions with values added to achieve co-progress with our customers.

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FAQ

Q: What are silica bricks?

A: Silica is a refractory ceramic which is widely used in the steel and glass industries. Silica bricks are prepared by kiln-firing quartz of low impurity content at a temperature of 1450°C, thereby converting at least 98.5% of it into a mixture of the more 'open', less dense forms, tridymite and cristobalite.

Q: What is the raw material of silica bricks?

A: Natural quartzite is used as the raw material for silica brick, and it must meet particular specifications in order to create the best brick qualities. If refractoriness or thermal expansion under load (creep) are important, a quartzite with a high chemical purity should be chosen.

Q: What temperature are silica bricks?

A: The firing temperature for silica bricks is usually around 1450-1600°C (2642-2912°F). The bricks are loaded into kilns or furnaces, and the temperature is gradually increased to allow for proper heat distribution and controlled expansion.

Q: What is the percentage of silica in the earth for good bricks?

A: Good brick earth should contain 50 – 60% of silica. It prevents cracking, shrinking, and wrapping of raw bricks. Silica imparts a uniform shape to the bricks. Excess of silica makes the bricks brittle.

Q: Are silica bricks acidic or basic?

Q: How to make silica bricks?

A: Silica bricks are prepared by kiln-firing quartz of low impurity content at a temperature of 1450°C, thereby converting at least 98.5% of it into a mixture of the more 'open', less dense forms, tridymite and cristobalite.

Q: What are the uses of silica brick?

A: Glass industry: Silica bricks are extensively used in the glass manufacturing industry due to their ability to withstand the extreme temperatures involved in glass production processes. They are employed as the lining material in glass tanks, melters, regenerators, and other glass-making equipment.

Q: What is the melting point of silica bricks?

A: High softening temperature under load is an excellent characteristic of silica bricks, generally 1640-1680°C, close to the melting point of tridymite (1670°C) and cristobalite (1713°C). The volume of silica bricks is stable in the range from above 300°C to close to the melting point (tridymite or cristobalite).

Q: What size are silica bricks?

A: Fire resistant rectangular silica insulation brick, size: 9 in. X 3 in. X 2 in.

Q: What are the physical properties of silica bricks?

A: Silica brick is an acidic refractory material, which has strong resistance to acidic slag erosion, but when it is strongly corroded by alkaline slag, it is easily damaged by oxides such as AI2O3, and has good resistance to oxides such as CaO, FeO, and Fe2O3.
The thermal conductivity of silica bricks increases with the increase of working temperature, without residual shrinkage. During the oven process, the volume of silica bricks increases with the increase of temperature. In the oven process, the maximum expansion of silica brick occurs between 100 and 300 ℃, and the expansion before 300 ℃ is about 70% to 75% of the total expansion. The reason is that SiO2 has four crystal form transformation points of 117℃, 163℃, 180~270℃ and 573℃ in the oven process. Among them, the volume expansion caused by cristobalite is the largest between 180~270℃.

Q: What color will appear after silicon bricks are fired?

A: After the silica brick is fired, there will be dark or shallow spots on the surface. This is because after the crystal form is fully transformed, the residue left is now on the surface of the brick, and the color of the silica brick is yellow or yellowish red. , some are white and yellowish in color, but the spots on the surface do not affect any indicators or quality problems.

Q: What temperature are silica bricks?

Q: Why are silica bricks used in coke ovens?

A: As stated earlier, the walls between the coking and the combus- tion chambers are mostly made of silica bricks in appreciation of the following advantages: High volume stability due to small thermal expansion at and above 800°C; and High strength and high refractoriness under load at high tem- perature.

Q: Does excess of silica makes the brick brittle on burning?

A: The durability of bricks depends on the proper proportion of silica in brick earth. The excess of silica destroys the cohesion between particles and the bricks become brittle.

Q: What are the characteristics of silica bricks?

A: The high load softening temperature of silicon brick reaches 1640-1670ºC. The stability of volume change ensures that it maintains its structural integrity and performance under extreme high-temperature conditions.
The acid resistance and slag erosion resistance of silicon brick protect it from chemical corrosion in environments with acidic or corrosive substances, for example, CaO、FeO、Fe2O3, and other oxides. It is different from mag carbon bricks.

Q: What are the precautions for using silica bricks?

A: Silicon bricks are not suitable for alkaline working environments. They are easily damaged by oxides containing Al2O3, K2O, and Na2O.
They are not suitable for working in environments below 800 degrees Celsius because of poor earthquake resistance. Below 800 degrees Celsius, the furnace needs to be slowly heated and cooled.

Q: How to produce silica bricks?

A: Silica bricks for sale adopts SiO2 rock as the raw materials and require less than 2% Al2O3, TiO2 and alkali metal oxide content. Its manufacturing process is similar to ceramics.
Silica refractory brick properties have a close relation with crystal type transform of SiO2 in the process. True specific gravity is an important quality index, which should below 2.38. Less true specific gravity means the more quantity of tridymite and cristobalite and less quantity of residual quartz, which as a result of low residual linear expansion and low reduction in strength.

Q: When making silica bricks, what is the commonly used binder?

A: The binders used in the manufacture of silica bricks include sulfite pulp waste liquid and lime milk. When lime milk is used as a binder, it acts as a plasticizer. Milk of lime increases the strength of the brick during drying, and becomes a mineralizer during firing, promoting the transformation of quartz.
Lime should contain a lot of active CaO, undecomposed CaCO3 and MgCO. Not more than 5%, Al, O3+Fe2Og+SiO; not more than 5%. When it contains large particles of under-burned Ca-CO3 and over-burned lime, the product will produce molten holes, which will affect the quality of the product.

Q: How to reduce the dimensional tolerance of silica brickss during molding?

A: The flatness and deflection of the hammer head should be checked before forming to prevent unevenness or deflection of the hammer head; the flatness of the forming table and the brick ejector should also be checked before forming, so that the hammer head can be adapted to the upper template; after forming, the brick blanks should be checked. Check the ruler block by block to ensure that the blank meets the dimensional tolerance requirements.

Q: What is the composition of silica bricks?

A: This is made from siliceous clays and contains mainly cristobalite bonded with a glassy phase. It typically contains 18–25% alumina and 72–80% silica. This brick has excellent load-bearing ability to 1300 °C, but like regular silica brick it has a comparatively high thermal expansion from room temperature to 500 °C.

As one of the leading silica bricks suppliers in China, we warmly welcome you to buy or wholesale high-grade silica bricks in stock here from our factory. All our products are with high quality and competitive price.

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