The chemical composition of bauxite is mainly Al2O3, SiO2, Fe2O3, TO2, accounting for about 95% of the total composition, and the secondary components are CaO, MgO, K2O, Na20, S, MnO2 organic matter and trace components Ga, Ge, etc.
Calcined bauxite for refractory material
The chemical composition of bauxite is mainly Al2O3, SiO2, Fe2O3, TO2, accounting for about 95% of the total composition.
Al2O2 is the main chemical component of bauxite, and its occurrence state is mainly aluminum hydroxide, by aluminosilicate, which is clay minerals; in addition, it can also contain a small amount or trace amount in iron and titanium minerals. SiO2- generally exists as clay minerals, and rarely is free stone molybdenum.
Fe2O2 generally exists in the form of hematite in karst or sedimentary bauxite: the primary zone is often pyrite, less siderite, oolitic mud, and rarely magnetite, etc.; Belt (late weathering) and red seven-type bauxite are mainly goethite, others such as water hematite, water goethite and aluminum goethite, aluminum hematite, etc.
Rare. In addition, a small amount of iron often exists in diaspore, boehmite, gibbsite and corundum in a similar form.
The content of TiO2 in bauxite is usually 2%~4%, but there are also higher, which can reach 6%~12%, such as bauxite in southwestern Sichuan and India.
Both titanium and aluminum are inert elements in the process of parent salt weathering, so A/Ti often maintains a constant ratio in each mining area. In bauxite, the independent minerals of T element are mainly anatase and rutile, by brookite, leucite and ilmenite. There are also similar occurrences in aluminum minerals. In addition, it also occurs in other minerals in the form of gels.
S is a very harmful impurity in bauxite, and it generally exists in the form of pyrite. The pyrite content is higher in the acoustic zone of sedimentary or karst bauxite; the sulfur content in the oxidation zone or accumulation bauxite is lower, generally between 0.05% and 0.1.
Physical and chemical indicators of calcined bauxite
Project |
Al2O3% |
Fe2O3% |
TiO2% |
CaO+MgO% |
K2O+Na2O% |
Bulk density(g/cm3) |
water absorption |
GL-90 |
≥89.5 |
≤1.5 |
≤4.0 |
≤0.35 |
≤0.35 |
≥3.35 |
≤2.5 |
GL-88A |
≥87.5 |
≤1.6 |
≤4.0 |
≤0.4 |
≤0.4 |
≥3.20 |
≤3.0 |
GL-88B |
≥87.5 |
≤2.0 |
≤4.0 |
≤0.4 |
≤0.4 |
≥3.25 |
≤3.0 |
GL-85A |
≥85 |
≤1.8 |
≤4.0 |
≤0.4 |
≤0.4 |
≥3.10 |
≤3.0 |
GL-85B |
≥85 |
≤2.0 |
≤4.5 |
≤0.4 |
≤0.4 |
≥2.90 |
≤5.0 |
GL-80 |
>80 |
≤2.0 |
≤4.0 |
≤0.5 |
≤0.5 |
≥2.90 |
≤5.0 |
GL-70 |
70~80 |
≤2.0 |
- |
≤0.6 |
≤0.6 |
≥2.75 |
≤5.0 |
GL-60 |
60~70 |
≤2.0 |
- |
≤0.6 |
≤0.6 |
≥2.65 |
≤5.0 |
GL-50 |
50~60 |
≤2.5 |
- |
≤0.6 |
≤0.6 |
≥2.55 |
≤5.0 |
The use of calcined bauxite:
(1) Aluminum smelting industry. For, aviation, automobiles, electrical appliances, chemicals, daily necessities, etc.
(2) Precision casting. The bauxite clinker is processed into fine powder to make a mold and then precision cast. For medical, aerospace, communications, instrumentation, machinery and medical equipment sectors.
(3) For refractory products. High alumina bauxite clinker has a refractoriness of up to 1780℃, strong chemical stability and good physical properties.
(4) Aluminum silicate refractory fiber. It has the advantages of light weight, high temperature resistance, good thermal stability, low thermal conductivity, small heat capacity and mechanical vibration resistance. For steel, non-ferrous metallurgy, electronics, petroleum, chemical, aerospace, atomic energy, and other industries. It is to put high-alumina clinker into a high-temperature electric arc furnace with a melting temperature of about 2000-2200 ° C, and after high-temperature melting, high-pressure high-speed air or steam injection, and cooling, it becomes white "cotton" - aluminum silicate refractory fiber. It can be pressed into fiber blanket, board or woven into cloth to replace refractory bricks lining high temperature furnaces in smelting, chemical, glass and other industries. Firefighters can use fire-resistant fiber cloth to make clothes.
(5) Using magnesia and bauxite clinker as raw materials, adding appropriate binder, it is very effective for pouring the overall lining of the ladle.
(6) Manufacture of various compounds of alumina cement, abrasive materials, ceramic industry and chemical industry that can make aluminum.
In recent years, bauxite powder and bauxite have been widely used in common cast steel coatings and cast iron coatings due to their high fire resistance, good chemical stability, small expansion coefficient, rich source and low price.
GONGYI YUYING REFRACTORY CO.,LTD is located in GONGYI ZHENGZHOU CITY HENAN province,which is one of the main refractory production bases in China. Main products include different kinds of refractory brick and refractory material :Such as Fire Clay Brick, High Alumina Brick, Light Weight Insulating Brick,expanded clay,ceramic fiber blanket,rock wool products etc.They are widely used in Iron and steel, Nonferrous metals, BuildingMaterials(Cement,Glass,Ceramic), Petrochemical, Energy & Incineration etc industries.
It is widely used in the lining of the kiln working face which is in direct contact with the flame, and has become one of the research hotspots in recent years.
Common low-creep high-alumina bricks can be used in blast furnace hot blast stoves, as well as other industrial kilns, and can also be made into low-creep high-alumina bricks of different sizes according to specific construction requirements, such as lattice bricks, special-shaped bricks, anchor bricks, etc. , mainly used in industrial kilns in long-term high temperature environments
Refractory wet mud used to block the iron outlet can be divided into two categories: water cannon mud and waterless gun mud. On large and medium -sized blast furnaces on high top pressure and high degree of smelting.
Corundum refractory castable has the characteristics of high strength and good fluidity, which is convenient for construction. It is mainly used for the parts that are easy to be washed and worn, such as the combustion chamber, separator and flue of circulating fluidized bed boiler.
Castables Refractory for cement kiln Castables for cement kilns are special refractory castables for cement kilns. In my country, the new dry-process cement technology is developing rapidly, and the design and brick shape of PC and SP kilns are also very complicated. In order to adapt to this situation, our factory has developed a series of new refractory castables to replace the traditional refractory materials. Practice has proved that it is more suitable to use castables in parts with complex structure and kiln body deformation. Castables are also suitable for coolers, preheaters, precalciners, kiln door covers, tertiary air ducts and other parts that require thermal insulation. Its varieties include alkali-resistant castables, high-alumina and corundum castables, heat-insulating castables, and steel fiber reinforced refractory castables. Gongyi Yuying Refractory Co., Ltd. operates: castables for cement kilns, prefabricated blocks, low cement castables, refractory mud, refractory ramming materials, corundum castables, refractory castables, steel fiber castables, steel jade castables, Refractory plastics, high alumina castables, wear-resistant castables, plastics, castables, clay castables, refractory castables manufacturers, the company has 160 employees, including 12 senior professional and technical personnel, with an annual production capacity of 60,000 tons , has light and heavy material production lines, various production, testing and testing equipment, including 10 sets of 400-ton to 1,000-ton series forming presses, two (148 meters long and 118 meters long) high temperature tunnel kiln . Castables are also suitable for use in some parts of coolers, preheaters, precalciners, kiln door covers and tertiary phoenixes. Suitable thermal insulation castables can be used in preheaters of cement kilns and other parts that require thermal insulation. The main castables used in cement kilns are: index Alkali resistant castable High alumina castable High Alumina Steel Fiber Castable High strength mullite castable Silicon carbide anti-skin castable GT-13NL G-16 GF-16 G-20G GC-13H Al2O3%≥ 35 65 65 65 55 SiO2+SiC%≥ - - - - 35 Bulk densityg/cm3≥ 2.10 2.5 2.5 2.60 2.5 Cold pressed strengthMpa≥ 110℃×24h 60 80 80 80 80 1100℃×3h 60 80 80 90 100 Flexural strengthMpa≥ 110℃×24h 6 8 9 8 8 1100℃×3h 6 8 9 9 10 Rate of change of line after burning 1100℃×3h ±0.5 ±0.3 ±0.3 ±0.3 ±0.3 1. Alkali resistant castable Experiments show that the alkali pouring material has excellent alkali resistance much better than ordinary clay or high alumina pouring material. Ordinary and low-cement alkali-resistant castables have been successfully used in double-layer structural linings for preheater roofs, cones, tertiary air ducts, etc., where shaped bricks are not suitable. The low-cement alkali-resistant pouring material can also be used in the rear kiln mouth, cooler and kiln door cover. 2. High alumina and corundum castables High alumina and corundum castables for cement kilns include low cement and ultra-low cement castables, high strength corundum castables, etc. Calcined bauxite and cut jade are used as aggregates in the castable. Low cement and ultra-low cement type high alumina castables can be used in front and rear kiln mouths, chain belts, kiln door covers and cooler side walls. 3. Insulation casting section The heat-insulating castables for cement kilns include ordinary heat-insulating castables, high-strength heat-insulating castables, and ordinary and low-cement alkali-resistant heat-insulating castables. Usually high alumina cement is used as a binder in the castable. Ordinary heat-insulating castables use expanded perlite, expanded vermiculite and waste light bricks as aggregates. High-strength heat-insulating castables use refractory clay ceramsite, fly ash ceramsite, shale ceramsite, etc. as aggregates. Alkali-resistant and heat-insulating castables use alkali-resistant lightweight aggregates. Ordinary heat-insulating castables and their prefabricated blocks can be used as heat-insulating villages in double-layer structural linings of coolers, preheaters, calciners, kiln door covers and tertiary air ducts; high-strength heat-insulating castables and their prefabricated Blocks are available as single-layer linings in the neck and disintegration zones of conventional kilns. Ordinary and low-cement alkali-resistant and heat-insulating castables can be used in preheaters in small and medium-sized kilns and other parts that require alkali-resistant heat insulation. 4. Steel fiber reinforced refractory castables Adding steel fiber can improve the dismantling strength of the castable, and greatly improve the thermal shock resistance, impact resistance and wear resistance of the castable. Our company has carried out a lot of systematic research on steel fiber reinforced refractory castables, and developed a series of steel fiber reinforced refractory castables.
High alumina brick is one of the indispensable basic refractory materials in the upper and middle parts of blast furnace body in iron and steel industry