Factors affecting the price of high alumina bricks

November 02, 2018

Factors affecting the price of high alumina bricks

High alumina bricks have various specifications and prices. When buying high alumina bricks, how to know the price depends on the following factors.

(1) Alumina content

One of the important properties of high alumina refractory bricks is the structural strength at elevated temperatures, usually assessed by refractoriness under load, sometimes by high temperature creep. The experimental results show that the refractoriness under load increases with the increase of Al2O3 content. High alumina brick manufacturers divide high alumina bricks into three grades according to Al2O3 content: Grade I - Al2O3 content > 75%; Grade II - Al2O3 content is 60 ~ 75%; Grade III - Al2O3 content is 48 ~ 60%, in general, three grades divide the high alumina bricks into three price ladders.

(2) Product performance

1. Refractoriness

The high alumina bricks have higher refractoriness than clay bricks and semi-silica bricks, reaching 1750℃~1790℃. It is a high-grade refractory material. The higher the refractoriness, the better the performance and the relative price will be increased by weight.

2. Refractoriness under load

Because the high alumina products have high Al2O3 content, less impurities and less fusible glass body, the refractoriness under load is higher than that of the clay bricks. However, since the mullite crystal does not form a network structure, the refractoriness under load is not as high as the silica bricks.

3. Slag resistance

Al2O3 content is more in high alumina brick, close to neutral refractory products, and can resist the erosion of acid slag and alkaline slag. However, due to the presence of SiO2, the ability to resist alkaline slag is weaker than acid slag.

(3) Size

The size of high alumina bricks is generally divided into national standard, special type and specific type. The size of the national standard is fixed, the production enterprises can produce in large quantities, so the price is relatively low; while the size and shape of the special shaped and specific type are not fixed, besides the general special shaped bricks, the enterprises usually needs to customize the production, which requires the cost of mold opening, production difficulties also increase depending on the complexity of the shape, so the price is relatively high.