Professional Fire Clay Refractory Bricks
Introduction
Professional fireclay Refractory brick is a kind of High Alumina Refractory Bricks, Fireclays are clays that are immune to deformation and melting at high temperatures in the ceramics industry. Unfired refractory bond clay and fireclays (chamotte), fired refractory clay, or similar grog ingredients are used to make fireclay refractory bricks. The basic components of fireclay refractory bricks are 18 percent to 44 percent alumina (Al2O3) and 50 percent to 80 percent silica (SiO2). The main component of refractory fireclay is hydrated aluminum silicates, with tiny amounts of other minerals. Al2O3.2SiO2.2H2O is the standard formula for these aluminum silicates, which equals 39.5 percent alumina, 46.5 percent silica, and 14 percent water (H2O). The most prevalent member of this category is kaolinite. The mixed water is driven off at high temperatures, leaving a residue that is 45.9% alumina and 54.1 percent silica in theory. Even the cleanest clays, however, include trace amounts of other components such as iron, calcium, magnesium, titanium, sodium, potassium, lithium, and free silica. The total amount of these melting point-lowering fluxing agents should be no more than 5% to 6% of the overall amount. TiO2 is not considered a fluxing agent, however it was previously counted alongside alumina.
This fireclay brick is made of high quality raw flint clay or Kaolin material with less impurities, compact structure and high purity. It is added with new refractory raw materials, additives and binders, fireclay brick is formulated by high-temperature sintering after compounding, mixing and high-pressure molding. It has the advantages of small creep rate and strong heat storage capacity.
Therefore, the raw materials for producing professional fireclay bricks must be dense in structure, high in purity, and low in impurities, so as to avoid excessive liquid phase in the product during firing to reduce creep resistance and increase heat resistance of low creep clay bricks. Shock and erosion resistance.
Features:
1. Good stability.
2. Low creep rate.
3. Good abrasion resistance.
Professional fireclay bricks Technical Index
Item / Types | XHJZN-45 | XHJZN-40 | XHJZN-36 | |
Chemical Composition | Al2O3(%) | ≥45 | ≥40 | ≥36 |
SiO2(%) | ≤50 | ≤55 | ≤60 | |
Fe2O3(%) | ≤1.2 | ≤1.5 | ≤1.8 | |
Na2O+K2O(%) | ≤1.0 | ≤1.0 | ≤1.0 | |
Bulk Density | g/cm3 | 2.00~2.40 | ||
Apparent Porosity | % | ≤16 | ≤19(22) | ≤22(24) |
Cold Crushing Strength | MPa | ≥60 | ≥40(35) | ≥35(30) |
Refractoriness | 0.2MPa (℃) | 1430 | 1380 | 1350 |
Flexural strength | 1200℃ | - | - | - |
1350℃ | - | 6 | 6 | |
Professional fireclay bricks Characteristics
l Good thermal shock resistance.
l Good abrasion resistance.
l Good corrosion resistance.
l Good high temperature mechanical strength.
l Good volume stability, low creep rate.
With the development of modern smelting technology, hot blast stoves generally adopt high air temperature technology, and the service life of hot blast stoves is required to be longer: therefore, higher requirements are put forward for the comprehensive performance of refractory materials for hot blast stoves. Damage to refractory materials used in hot blast stoves is usually caused by thermal stress, chemical attack, and mechanical loading. It is generally believed that an important reason for the damage of the hot blast stove is that the high temperature creep resistance of the refractory material is poor, resulting in collapse, deformation and cracking of the lining refractory material, thus causing widespread concern for low creep bricks for hot blast stoves.
Applications
In addition to refractoriness, many other qualities affect the usage of fireclay bricks. Dimensional precision, crushing strength, porosity, and refractoriness under strain are some of these qualities. Many applications call for machine-pressed, fired fireclay refractories. The materials are subjected to a wide range of stresses. It is normal to create bricks that are designed to satisfy specific needs for unique uses. In the steel industry, fireclay refractory bricks are used in coke oven batteries, blast furnaces, hot blast stoves, and a variety of other furnaces.
