Synthetic mullite introduction

Mullite (Mullite) is compound in atmospheric Al2O3-SiO2 two series in the only stable, chemical formula 3Al2O3 – 2SiO2, the theory of composition of Al2O3 71.8%, SiO2 28.2%. Mullite is a mineral name, because of the moire Island Natural Minerals first discovered on the west coast of Scotland (Mull) and the name. Natural mullite mineral is very small, Lin County of China’s Wuan County in Hebei province and Henan province has been found, but so far the world has yet no industrial value of the deposit. Mullite artificial synthetic stone commonly used sintering method or electric melting method. Synthesis of mullite in 1926 and the first with electric melting method, in 1928 the successful development of sintering method. Currently the world’s electric melting mullite consumed 10000~20000 tons, 500000~600000 tons of sintered mullite. Synthesis of mullite is a high-quality refractory raw material; it has the expansion uniformity, thermal shock stability, excellent high load softening point, high temperature creep value characteristics of small, high hardness, resistance to chemical corrosion and good.

Structure of refractory brick can also cause brick burst

Structure of refractory bricks will burst and its product itself also has the very big relations. Refractory brick thermal spalling, refers to the subject of the refractory brick thermal shock, in refractory brick surface and internal temperature difference, because of differences in thepresence of internal expansion, leading to refractory brick masonry produce stress, when the stress accumulation caused to a certain extent is the heat burst. So, cause the refractory brick thermal spalling reason which to have:

1, silica brick mineral phases such as quartz, tridymite, cristobalite, due to the temperature change and also accompanied by quartz crystal type conversion, volume change, so the heating or cooling brick masonry structure, the need to pay particular attention to the problem of thermal explosion.

2, magnesia brick and magnesia chrome brick, because its thermal expansion coefficient is larger, the thermal decrepitating temperature mutation is also easy to produce refractory brick.

3, insulating refractory brick, because of its low thermal conductivity, the temperature gradient in brick, and because of its relatively low strength, so it is also easy to produce hot crack problems.

As the introduction, is it right? Ofrefractory bricks have a further understanding of it; the content above is only for your reference, the specific reasons but also according to the specific circumstances to determine. More detailed content of http://www.yilongrefractory.com

Features of refractory fibers

1. High temperature.

The highest use temperature up to 1250~2500 DEG C. The most commonly used asbestos only 500~550 DEG C, slag wool is 580~830 DEG C, and aluminum silicate fiber above 1000 degrees.

2. Heat capacity is low.

Refractory fiber under high temperature heat conduction ability is very low, such as 1000 DEG C, conductivity of aluminium silicate fiber is only 20% light clay brick, clay brick 38%.

3. Small volume density.

Usually 0.1~0.2g/cm fand, general clay brick for 1/20~1/10, 1/10~1/5 light clay brick. Therefore, application of refractory fiber industrial furnace instead of refractory bricks, which can make the furnace body weight, furnace wall thickness. If the heating furnace using fiber lining reduces 80%, furnace wall thickness of 50%.

4. Good chemical stability.

In addition to alkali, fluoride, sulphate, erosion is almost unaffected by chemicals.

5. Good thermal shock resistances.

Both fiber materials and products of refractory brick, has the incomparable good thermalshock resistance.

6 low thermal capacity.

1/72 heat capacity of the fiber material only refractory brick, light clay brick 1/42.Refractory fiber lining for storage, loss is small, fuel saving, fast temperature rise, the intermittent operation furnace affection is obvious.

7. Soft, easy processing.

Can be made into a variety of products and personnel shape parts, construction is convenient, the labor intensity is low, the effect is good.