Refractory Corundum Mullite Brick Introduction
The main component of corundum mullite brick is AL2O3, which is refined by a variety of high-temperature raw materials through multiple production processes. The thermal shock resistance, refractoriness and service temperature of this product are higher than ordinary lightweight refractory bricks. Of course, corundum mullite brick price is also high than others normal refractory brick.
The corundum mullite brick is made of corundum and mullite, and the main crystal phase is a shaped refractory product of mullite and corundum. Corundum mullite brick is made of corundum and mullite as main raw materials, and is added at a high temperature in an oxidizing atmosphere by adding an appropriate amount of alumina, silica ultrafine powder and additives. Its AL2O3 content is 72%~90%, and the high temperature stable crystal phase is mullite and corundum. Its products are resistant to high temperature, erosion and chemical stability. It is an erosion-resistant high-quality refractory material. It has the high temperature performance of corundum material and the good thermal shock resistance of mullite. It has high temperature strength and very good resistance to erosion and erosion. It has been widely used in high temperature kiln such as blast furnace, ironmaking furnace and carbon black reaction furnace in China.
According to the main components of the corundum mullite bricks, the AL2O3 content is GMZ-75, GMZ-80, GMZ-85, and GMZ-88. In the grades, G, M, and Z are divided into Chinese, Pinyin, and Chinese. The numerical part indicates the mass percentage of the alumina content, and the main mineral composition of the corundum mullite brick is the corundum crystal phase. Has excellent high temperature physical properties.
This product uses high-purity fused corundum as the main raw material, and adopts advanced ultra-fine powder adding technology. After mixing, molding and drying, it is fired at high temperature in the shuttle kiln. The product has the characteristics of high refractoriness, good thermal shock resistance, high temperature strength, excellent corrosion resistance, strong slag resistance, small expansion coefficient, low creep and anti-flaking, and is suitable for high temperature kiln under various atmospheric conditions. Furnace use; widely used in ceramics, glass, frit, zirconia ceramics, fluorescent materials, electronic ceramics, magnetic materials, ceramic powder high temperature sintering and petrochemical industry gasifier, synthetic ammonia two-stage reformer, carbon black reactor and Glass industry high temperature furnace and other equipment.
The corundum mullite brick is a high-alumina refractory brick composed of corundum and mullite main crystal phases, and the corundum mullite brick refers to a refractory brick made of high-purity or relatively pure raw materials. The presence of low melting point oxide impurities reduces its high temperature performance. Corundum mullite bricks price are much more expensive than ordinary high alumina bricks.
Corundum Mullite Brick Performance
It has good high temperature strength, high temperature creep resistance, thermal shock resistance and erosion resistance. The physical and chemical properties of a typical corundum mullite brick are: Al2O3 ≥ 85%, Fe2O3 0.45%, apparent porosity 19%, normal temperature compressive strength greater than 55 MPa, load softening temperature greater than 1700 ° C, heating line change (1600 ° C, 3 h) ) -0.1%, thermal shock resistance (1100 ° C water cooling) greater than 30 times.
Refractory Corundum Mullite Manufacturing Process
The corundum mullite brick is usually made of synthetic mullite. The mullite granules can be used as the aggregate, the α-Al2O3 powder is used as the powder, and the fused or sintered corundum granules can be used as the aggregate and the synthetic mullite powder. Powder. Aggregate and powder are compounded according to a certain proportion and particle size grade, and the sulfite pulp waste liquid is used as a binder, and is fed in a certain order. Fully knead evenly and form with a friction brick press or hydraulic press. After the bricks are dried, they are fired at 1650 ~ 1750 °C. Some use fused or sintered corundum sand as aggregate, and the bauxite or clay mixed fine powder with a ratio of mullite or corundum mullite is used as a powder for batching bricks. The corundum mullite bricks produced are slightly less dense, so the process is not widely used.
Corundum Mullite Refractory Brick Process Points
Pure mullite raw materials synthesized from industrial alumina powder and pure clay, bauxite or silica as raw materials, especially the alkali metal oxide content should be as low as possible, and the products prepared by using moishi pellets as aggregates are resistant to heat. The vibration is good, but the corrosion resistance is slightly poor, refractory product with corundum sand as the aggregate has good corrosion resistance, but the thermal shock resistance is slightly poor.
