High alumina insulating bricks are also known as high alumina heat insulating bricks. It is the ideal insulation refractory material for industrial furnaces. It is characterized with high strength, low thermal conductivity, good insulation performance and low price.
It is a new type of lightweight insulating material which contains approximately 48% alumina, mullite and glass phase or corundum. It has such advantages as high porosity, small volume density, good insulation effect, high mechanical intensity, small thermal conductivity and long service life. For various industrial kilns & furnaces, it is a kind of essential refractory for energy saving and temperature preservation.
High alumina insulation brick is made by mud pouring method. The mud contains about 50% water. By adding a small amount of gypsum, the mud will quickly be solidified. An appropriate amount of phosphoric acid is added. The ratio of the dry raw materials and the phosphoric acid is controled within 1:0.7. Chemical reactions produce CO2. The reason why use phosphoric acid instead of hydrochloric acid and sulfuric acid is that the the phosphoric acid can increase the duration time of bubbles and enhance the structural strength of semi-finished products.
Since CO2 will be produced in the mud, the embryoid bodies should be removed after two hours to ensure that embryoid bodies become strong. Embryoid bodies should be dried for three days at a temperature of 60 ℃. The final step is firing. The semi-finished products should be fired at a temperature of 1600 degrees for about 4 days.
High Alumina Insulating Brick is widely used in lining or insulating layers of various industrial furnaces, and kilns in petrochemical, machinery, ceramic industry, such as lining and insulating layer of high temperature kilns, carbon black stove, gasifier, hydrogen manufacturing furnace and shuttle kiln, etc.
Zhengzhou sunrise refractory Co., Ltd. is a refractory supplier from China, offering various insulation bricks, such as high alumina insulation brick, fire clay insulation brick, silica insulation brick and mullite insulation brick.