Light weight mullite insulation bricks are made of high-quality and
high-purity refractory materials. According to the specific gravity
of the product, organic composite fillers are added, vacuum
extrusion molding, and high temperature sintering to synthesize
light mullite products. With its light weight and excellent thermal
insulation properties, lightweight mullite bricks are widely used
in the hot surface refractory lining or insulation layer of a
variety of thermal equipment, creating conditions for improving the
energy efficiency of the equipment.
High-alumina refractories with mullite as the main crystal phase
generally have an alumina content between 50% and 75%. The
refractory temperature of mullite lightweight brick can reach above
1790℃. The starting temperature of load softening is 1600-1700℃.
Pressure resistance at room temperature is slightly 70-260MPa. Good
thermal shock resistance. There are two types of sintered mullite
bricks and fused mullite bricks. Sintered mullite bricks are made
of high-alumina bauxite clinker as the main raw material, adding a
small amount of clay or raw bauxite as a binding agent, and forming
and firing. Fused mullite bricks use high alumina bauxite,
industrial alumina and refractory clay as raw materials, add
charcoal or coke fine particles as reducing agents, and are
manufactured by reduction fusion method after molding. The
crystallization of fused mullite is larger than that of sintered
mullite, and its thermal shock resistance is better than that of
sintered products. Their high temperature performance mainly
depends on the content of alumina and the uniformity of mullite
phase and glass distribution.
A high-alumina refractory with mullite (3Al2O3·2SiO2) as the main
crystal phase. Generally, the alumina content is between 65% and
75%. In addition to mullite, the mineral composition with lower
alumina also contains a small amount of glass phase and
cristobalite; the higher alumina contains a small amount of
corundum. Lightweight mullite bricks can be directly used for the
lining of high-temperature kilns, and have been widely used in
shuttle kilns, roller kilns, glass and petrochemical kilns.
Features of Lightweight Mullite Bricks: 1. Low thermal
conductivity, with good thermal insulation effect; 2. Low thermal
melting, due to low thermal conductivity, mullite series light
insulation bricks accumulate very little heat energy, which has
obvious energy saving effect in intermittent operation; 3. Low
impurity content has very low iron box alkali metal and other oxide
content, therefore, high refractoriness; high aluminum content
makes it maintain good performance in a reducing atmosphere; 4.
High compressive strength in hot state; 5. Accurate appearance and
size, speed up the masonry, reduce the amount of refractory clay
used, ensure the strength and stability of the masonry, thereby
extending the life of the lining; 6. It can be processed into
special shapes to reduce the number of bricks and joints.
Lightweight mullite bricks can be used as refractory lining or
thermal insulation layer of hot surface working layer. Application:
upper structure of glass melting furnace forehearth bricks,
modified plates, processing of upper structure of furnaces, E-glass
melting furnace bricks. Firing kilns, smelting kilns, refining
devices, heating devices, and other thermal equipment. Application
areas: ceramic industry, glass industry, steel industry,
petrochemical industry, aluminum industry, and other industrial
fields.