Insulating refractory material refers to a lightweight refractory material with high porosity,low bulk density,and thermal insulation properties.The disadvantage of this material is that its porosity ranges from 30%to 50%(0.3g/cm3 to 1.3g/cm3),which leads to tissue loosening,low mechanical strength,and poor wear resistance.Generally,it does not bear loads and is protected by dense refractory materials.It is often used for kiln wall insulation or drying room external wall insulation.

In recent years,the working faces of prefabricated tunnel kilns have also adopted lightweight high alumina or lightweight mullite;In this case,it is necessary to greatly improve the strength and resistance to airflow erosion of insulation refractory materials due to their direct contact with flames and bearing certain loads.Practice has proved that the kiln lining is made of refractory oxide hollow ball products with a hole diameter of less than 0.6mm and produced by foam.Because these materials have high compressive and flexural strength,their service life can be greatly improved.For example,the compressive strength(~10MPa)and service temperature(16000℃)of alumina hollow ball products are far higher than other lightweight refractory materials.

1.Mullite insulation bricks are a new type of energy-saving refractory material with high temperature resistance,high strength,low thermal conductivity,and significant energy-saving effect;It is suitable for ceramic roller kiln,electric porcelain and arts and crafts porcelain shuttle kiln,step-by-step heating furnace,etc.In recent years,prefabricated tunnel kilns have been applied in the wall material industry,with the following technical indicators:

a.Chemical composition:Al2O3:≥50%;Fe2O3:≤0.8%

b.Volume density:~1.2g/cm3

c.Normal temperature compressive strength:≥8MPa

d.Thermal shock resistance(1100℃air cooling):20 times

e.Load softening point(0.1MPa):≤1450℃

f.Thermal conductivity:W·(m·K)-1(350℃)≤1%(1550℃,12h)

g.Product specification(mm):400×four hundred×one hundred

2.The ceramsite lightweight refractory concrete block takes aluminate cement-65 as the combination agent,shale as the combination agent,ceramsite,fly ash ceramsite or high alumina ceramsite as the aggregate,and the lightweight product is formed by vibration or vibration compression method.The technical indicators of ceramsite lightweight refractory concrete blocks are as follows:

a.Level:GL premium product;GL First Class Product

b.Volume density after drying at 110℃(g/cm3):1.65;one point seven

c.Normal temperature compressive strength(MPa):40;thirty-five

d.110℃flexural strength after drying(MPa):3.5;three