refractory

Ceramic fiber board is a high-strength refractory fiber board made of ceramic fiber. It is an essential high temperature refractory material. Ceramic fiber board must be stored properly to fulfill its high temperature properties.

Ceramic fiber board is made of ceramic fiber cotton by vacuum forming. It has tough texture, high strength, superior high temperature performance, excellent support force, good tensile strength and impact resistance. Its strength is better than the fiber blanket and vacuum formed felt. It will be gathered together when contact with water and its hardness will be decreased. In this case, it is easy to fall off when touched. So, waterproofing is very important for the storage of ceramic fiber board.

Ceramic fiber board should be stored in dry circumstances with no water and moisture. The building should be watertight and kept dry. Ceramic fiber board should have waterproof plastic film inside and be covered with cartons and placed on the ground with pallets. It should be placed on pallaets without contact with the ground, at least 20 mm away from the ground. In the rain season, ceramic fiber products should be covered with a waterproof canvas. Pay attention to water leakage if it is stored in iron house.

As their names imply, refractory brick is used to withstand high temperature and flame, while insulation brick is used to insulate and reduce heat loss. The insulation bricks seldom directly contact flame, while refractory bricks can directly contact flame. Both have their advantages and are used in different parts of furnaces.

Insulation bricks always have thermal conductivity between 0.2-0.4 w/m.k (350±25℃), while refractory bricks have thermal conductivity above 1.0w/m.k(350±25℃). So, insulation bricks have better insulation performance than refractory bricks. the refractoriness of insulation bricks is usually under 1400 degree, while that of refractory bricks is above 1400 degree. insulation bricks are generally lightweight materials with a density between 0.8-1.0g/cm3, while that of refractory bricks is above 2.0g/cm3.

Refractory bricks have better mechanical strength, long service life and better chemical stability. They do not react with batch materials. They have better high temperature performance and can withstand high temperature up to 1900℃.

Refractory bricks and insulation bricksa are quite different. Their applications and functions are quite different. It is important to select the right materials according to the actual conditions.

Recently, as a new refractory material, zircon refractory material has been developed. In the refractory industry, natural zircon minerals and artificial extracted or synthetic zircon oxides and composite oxides have been widely developed.

Zircon materials have been more widely used in the glass industry, metallurgical industry, cement industry, ceramics industry and refractory industry, due to high melting temperature, good chemical stability, good thermal shock, and good resistance to molten metals, slags or glass liquid.

Zircon materials are mainly used in the melting zone, superstructure, sidewall and throat. Zircon refractory materials mainly include dense zircon brick, fused cast AZS block, fused cast zircon mullite brick and rebounded AZS brick.

Zircon materials have a wide application in the metallurgical industry. According to the material, zircon materials can be divided into zircon brick, zirconite bricks, alumina zircon carbon products, zircon carbon products, zirconic acid calcium products, zirconium diboride products and zirconium oxide modified refractories.

Zirconite products have good high temperature resistance, good resistance to acid slags, low thermal expansion coefficient and good thermal shock resistance. It can be used in the ladle lining and critical parts such as the slag line and the outlet. It can also be used in the ladle nozzle, tundish nozzle and pocket block.

As we all know, alpha-beta fused cast alumina block is widely used in industrial furnaces. It is composed of alpha alumina and beta alumina crystals in a most ideal proportion which is approximately 50% and 50% respectively, where intertwined crystals of both materials result in a very dense structure.

Alpha-beta fused cast alumina block is made of high quality fused alumina as the raw material.

1) White fused alumina
White fused alumina is made of industrial alumina powder as the raw material. It is melted in an arc electric furnace and crystalized by cooling. White fused alumina is white and abbreviated as WFA.

2) Dense fused alumina
Dense fused alumina is made of industrial alumina powder as the raw material with the addition of additives. It is melted in an arc electric furnace and crystalized by cooling. It is gray or hoary and abbreviated as OFA.

3) Sub-white fused alumina
Sub-white fused alumina is also called high alumina corundum. It is made of bauxite as the main raw material with addition of additives. It is melted in an arc electric furnace and crystalized by cooling. It is brown grey or gray and abbreviated as SFA.

4) Gray fused alumina
Gray fused alumina is made of bauxite as the main raw material with addition of additives. It is melted in an arc electric furnace and crystalized by cooling. It is chocolate brown and abbreviated as BFA.

Below 1350 degree, alpha-beta fused cast alumina block has excellent corrosion resistance to glass liquid. It is widely used in the working tank of glass furnaces.

The fuse cast alumina block is a kind of cast product with rough surface and big size tolerance. In actual use, in order to reduce the brick joints, factories machine it with diamond tools. This can save energy and prolong the service life of the furnace.

Fused cast alumina block can be divided into alpha-beta block, alpha block and beta block.

Alpha-beta fused cast Alumina Block is formed by the compact structure of alpha alumina and beta alumina crystals in a most ideal proportion which is approximately 50% and 50% respectively, where intertwined crystals of both materials result in a very dense structure. It has dense structure and no contamination to glass. It is the ideal refractory materials for channels, spouts and working ends of floating glass furnace.

Alpha fused cast alumina block is an ideal product for the lower temperature zones of the glass melting furnaces due to its high density, superior corrosion resistance and low blister potential. It is also an ideal material for Metallurgical Titanium Furnace because the superior thermal stability.

Beta fused cast alumina block comprises of a majority of beta alumina crystals and a slight portion of alpha alumina crystals in compact structure. Moreover, the intersected texture of large ß-alumina ensures great dimensional stability and great resistance against spalling. Its property of base saturation enables a higher resistance to alkali vapor, thus it has excellent thermal shock resistance and does not form molten droplets. It is the best material for molter crown, port crown, feeder channel, ect.

Recently, the mechanical processing technology of the refractory materials has seen development. The pre-assembling of the refractory materials has already been adopted aboard. After the products are processed, pre-assembled, numbered and accepted, it is transported from the factory. This can save the time of cold repair and hot repair.

Zhengzhou sunrise is a refractory supplier from China. We offers various refractory materials for glass furnaces, such as fused cast AZS, fused cast alumina block, fused cast high zircon block, etc..

There are three ways to install ceramic fiber lining: external thermal insulation, internal thermal insulation and intermediate thermal insulation. The intermediate thermal insulation, due to its drawbacks, is rarely used.

The ceramic fiber materials used to install the ceramic fiber linin include ceramic fiber board, ceramic fiber blanket and ceramic fiber module. The lining is generally 25-50mm, and 50-100mm is preferred.

1) External thermal insulation
The ceramic fiber board is pasted or anchored to the cold surface of the furnace walls. This structure simply needs low temperature fiber products or lightweight bricks.

2) Internal thermal insulation
Ceramic fiber board is pasted on the hot surface of the furnace walls. It has good thermal insulation performance in either batch or continuous furnaces. It can reduce the heat loss of the furnace wall and the regenerative loss.

3) Intermediate thermal insulation
The ceramic fiber layer is installed in the middle of the furnace wall.

The adhesives commonly used include agents made with Silica gel and water glass or mud formulated with Portland cement and sulphate.

Now most furnaces adopt the internal thermal insulation structure, since it has high thermal efficiency, good energy-saving effect and long service life. Of course, in some cases, the structure and construction method should be chosen based on the actual situation.

Zhengzhou sunrise refractory Co., Ltd. is a refractory supplier from China, specializing in various ceramic fiber materials for glass furnaces, such as ceramic fiber board, ceramic fiber blanket, ceramic fiber module, etc.

High alumina insulating bricks are also known as high alumina heat insulating bricks. It is the ideal insulation refractory material for industrial furnaces. It is characterized with high strength, low thermal conductivity, good insulation performance and low price.

It is a new type of lightweight insulating material which contains approximately 48% alumina,mullite and glass phase or corundum. It has such advantages as high porosity, small volume density, good insulation effect, high mechanical intensity, small thermal conductivity and long service life. For various industrial kilns & furnaces, it is a kind of essential refractory for energy saving and temperature preservation.

High alumina insulation brick is made by mud pouring method. The mud contains about 50% water. By adding a small amount of gypsum, the mud will quickly be solidified. An appropriate amount of phosphoric acid is added. The ratio of the dry raw materials and the phosphoric acid is controled within 1:0.7. Chemical reactions produce CO2. The reason why use phosphoric acid instead of hydrochloric acid and sulfuric acid is that the the phosphoric acid can increase the duration time of bubbles and enhance the structural strength of semi-finished products.

Since CO2 will be produced in the mud, the embryoid bodies should be removed after two hours to ensure that embryoid bodies become strong. Embryoid bodies should be dried for three days at a temperature of 60 ℃. The final step is firing. The semi-finished products should be fired at a temperature of 1600 degrees for about 4 days.

High Alumina Insulating Brick is widely used in lining or insulating layers of various industrial furnaces, and kilns in petrochemical, machinery, ceramic industry, such as lining and insulating layer of high temperature kilns, carbon black stove, gasifier, hydrogen manufacturing furnace and shuttle kiln, etc.

Zhengzhou sunrise refractory Co., Ltd. is a refractory supplier from China, offering various insulation bricks, such as high alumina insulation brick, fire clay insulation brick, silica insulation brick and mullite insulation brick.

Ceramic fiber bulk is an excellent inorganic non-metallic material with various types and advantages of good insulation, heat resistance, corrosion resistance and high mechanical strength.

Ceramic fiber bulk is made of glass balls or waste glass by melting, drawing, winding and weaving. The diameter of the monofilament is several microns to twenty microns, equivalent of 1/20-1/5 of a single human hair. Each bundle of fiber precursor is composed of hundreds or even thousands of monofilaments.

Ceramic fiber bulk has good insulation performance. According to the physical principle, gas has low thermal conductivity, so excellent insulation materials usually have many air holes inside them. Ceramic fiber bulk has many air holes inside it and its fibers are in irregular arrangement, so it is an excellent insulation material with a low thermal conductivity of 0.03w/cm.k.

Ceramic fiber bulk has advantages of noncombustible, no distortion and no embrittlement. It can resist high temperature up to 700 degrees and has A1 level of combustion performance.

Ceramic fiber bulk has good corrosive resistance to strong acid and good recoverability. It has high tensile strength, more than 1.0kg, so it can resist any shock and vibration. It has low moisture absorption rate, close to zero.

Ceramic fiber bulk does not contain any bonding agent and has no smell and no toxic. Compared with the traditional glass wool and rock wool, it does not contain any bonding agent and will not give off any toxic, acrid smoke at high temperature.

Ceramic fiber bulk is usually used in the interior compartments and ceilings of advanced buildings and for the insulation of metal duct or the inner walls of bellows, noise absorption within the room and sweat control of metal ceilings.

Refractory selection for crowns of glass furnace regenerators must recognize both the functions of the refractories and the operating environment within the chambers.

The main function of crowns is to limit thermal losses. The main operating factors to be considered are temperature, repeated temperature cycling, airborne particulates, volatiles and load. Fuel and glass composition must also be considered when deriving the refractory specifications.

The main refractories for the crowns of glass furnace regenerators include basic refractories, silica brick, mullite brick and alumino silicates refractories. In making the choice, the resistance to creep and chemical attack must be taken into consideration.

The temperature is very important for the refractory choice. Basic refractories have limits in creep resistance. If the temperature is close to 1,500°C and the material is under a strong compression, life limiting creep will ensue. As a consequence, basic refractories can be used only if the operating temperature is lower than 1,500°C (1,460-1,480°C).

Considering only creep resistance, silica brick is the best refractory because of its lack of glassy phase and its different crystalline structure, which avoids plane slipping. Furthermore, creep starts only at temperatures close to 1700°C. Mullite brick is another quality suitable for the crowns for its excellent creep resistance.

Basic refractories have a very good chemical resistance to the alkaline gases coming from the glass furnace, but they are susceptible to carry-over enriched with silica and subsequent forsterite formation at the hot face. This chemical reaction increases volume and leads structure to a collapse.

Basic refractories can be used in the crowns temperatures lower than 1,500°C (1,460-1,480°C). Silica brick is not suggested for crowns because condensation of alkali in the colder zones of the masonry would lead to corrosion, loss of mass and also holes.

Mullite brick reacts with alkali and slags to form a series of layers which prevent alkali penetrating into the refractory and wear proceeds at a minimal rate while the thermo-mechanical properties are preserved. Mullite brick is a good choice for crowns but it must have high mullite content (95-97%).

Zhengzhou sunrise refractory Co., Ltd. is a refractory supplier from China, specializing in various refractories for glass furnaces, such as fused cast AZS block, magnesia bricks, silica brick and mullite bricks.

Ceramic fiber module is made of ceramic fiber blanket by folding and compressing. Currently, it gradually becomes the first choice for the thermal insulation of industrial furnace linings.

Ceramic fiber module has white color and regular size. It can be directly fixed to the anchor nail on the steel plate of the furnace shell. It has good insulation performance and can improve the integrity of the furnace. It simplifies and speeds up the construction of furnaces and promotes the masonry techniques of furnaces.

It has many advantages over the ceramic fiber blanket.
1) During installation, after releasing the tying, the folded blankets can generate a huge stress, which makes them crowded together tightly without gaps.
2) The flexibility of ceramic fiber blanket can compensate the deformation of the furnace shell and reduce the construction غير مجاز مي باشدt. At the same time, it can make up the gaps caused by the thermal changes of the different components.
3) Since it has light weight and low thermal capacity, it can significantly reduce the energy غير مجاز مي باشدt during the temperature operation.
4) Flexible ceramic fiber blanket can withstand external mechanical forces.
5) It has good resistance to thermal shock.
6) The ceramic fiber lining requires no drying and maintenance. It can be put into use immediately after the construction is completed.
7) It has stable chemical properties. It is not eroded by acids, bases, water, oil and vapor, except phosphoric acid, hydrofluoric acid and strong base.

It can be used for the furnace lining insulation in the petrochemical industry, metallurgical industry, ceramic industry, glass industry, heat treatment industry and other industries.

Zhengzhou Sunrise Refractory supplies various ceramic fiber products including ceramic fiber blanket, ceramic fiber board, ceramic fiber module, ceramic fiber vacuum formed shapes, calcium silicate board, ceramic millboard, ceramic fiber paper, ceramic fiber bulk, and ceramic fiber cloth tape, rope and yarn.