Refractory materials - refractory bricks advantages and features introduced

Refractory bricks, referred to as fire bricks, have a certain shape and size of the refractory material. According to the preparation process can be divided into fired bricks, non-fired bricks, electrofusion bricks (fusion casting bricks), refractory heat-insulating bricks; according to the shape and size can be divided into standard bricks, ordinary bricks, special-type turn and so on. Can be used as a building kiln and a variety of thermal equipment, high temperature building materials and structural materials, and at high temperatures can withstand a variety of physical and chemical changes and mechanical effects.

For example, refractory clay bricks, high aluminum bricks, silicon bricks, magnesium bricks and so on.

Characteristics:

1, chemical composition: the main components determine the quality and characteristics of the refractory material.

2, bulk density: unit volume weight, high density, indicating good densification, strength may be high, but the thermal conductivity may be large.

3, the apparent porosity: did not do specific requirements, but as a manufacturer must strictly control the apparent porosity.

4, load softening temperature: also known as high temperature load start deformation temperature, this parameter is very important, marking the material resistance to high temperature resistance.

5, thermal shock resistance: the ability to resist rapid changes in temperature without being destroyed.

6, compressive strength: withstand (room temperature) the maximum pressure capacity.

7, Flexural strength: the ability to withstand shear pressure.

8, linear rate of change: also known as the re-burning line change or residual line change, refers to each time in the same temperature change in the volume of expansion and contraction changes, such as each expansion and contraction of the same, we define such a linear rate of change of 0.

9, abrasion resistance: we all know that I will not say more, it is one of the best indicators of the quality of refractory materials.

10, thermal conductivity: unit temperature gradient conditions, through the unit area of the material heat flow rate, and porosity.

11, impact resistance: good impact resistance, long service life.

12, slag resistance: at high temperatures small resistance to slag erosion without being destroyed.

Commonly used refractory materials

1, high alumina brick: Al2O3 content greater than 75 or more, refractoriness higher than clay bricks, good resistance to acid and alkali erosion, suitable for cement kiln firing zone, etc.

Refractory bricks.

2, dolomite bricks: hanging kiln skin performance, good erosion resistance, but there are bricks more or less f-CaO, easy to hydrate, difficult to transport and storage, the production of less.

3, magnesium-chromium bricks: hanging kiln skin good, mostly used in the firing belt, the disadvantage is the poor performance of thermal shock resistance, coupled with the hexavalent Cr is highly toxic, the international production and use of magnesium-chromium bricks in the country is gradually reducing the production of the brick is now used to find alternatives to the production unit as soon as possible.

4, spinel bricks: mostly used in excessive band, good seismic performance, good reduction resistance, but refractoriness is slightly worse.

5, anti-spalling bricks: this brick contains a small amount of ZrO, in the process of temperature rise in the formation of fine cracks in the martensitic phase transition, with strong alkaline resistance, anti-spalling and slag resistance is good.

6, phosphate bricks: low refractoriness, but high strength and good thermal shock, mostly used in castor cooler, kiln hood and other uses.

7, silicon carbide bricks: high temperature (1800 degrees or so, load softening temperature in 1620-1640), small coefficient of thermal expansion, cold and heat wear resistance are good for cooling belt and kiln mouth.

8、Silica Mo brick: good thermal shock, high strength, good abrasion resistance, suitable for excessive belt.