High alumina cement (formerly known as bauxite cement) is a hydraulic cementitious material with aluminate as the main mineral component, which is prepared by bauxite and lime in a certain proportion, calcined and ground, also known as aluminate cement. It exhibits exceptional refractory properties, including high temperature resistance, excellent thermal shock resistance, and low shrinkage at elevated temperatures. This cement is specifically designed for applications in high-temperature environments such as furnace linings, kiln linings, and other refractory installations.
| Item/Grade | CA50 | CA70 | CA80 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| A600 | A700 | A900 | CA70 | CA70W | CA70S | CA71 | CA80 | CA80S | |||
| Chemical Composition | ω (SiO2) ≤/% | 7.8 | 7.5 | 5.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | |
| ω (Al2O3)/% | 50.0 | 51.0 | 53.5 | 68.5-70.5 | 68.5-70.5 | 68.5-70.5 | 69.5-71.5 | 78.0-81.0 | 78.0-81.0 | ||
| ω (Fe2O3) ≤/% | 2.5 | 2.5 | 2.5 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | ||
| ω (CaO)/% | / | / | / | 28.5-30.5 | 28.5-30.5 | 28.5-30.5 | 27.5-29.5 | 17.5-20.5 | 17.5-20.5 | ||
| ω (MgO) ≤/% | / | / | / | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | ||
| ω (R2O) ≤/% | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | ||
| ω (S) ≤/% | 0.1 | 0.1 | 0.1 | / | / | / | / | / | / | ||
| ω (Cl) ≤/% | 0.1 | 0.1 | 0.1 | / | / | / | / | / | / | ||
| Fineness | d50/μm | / | / | / | 11-4 | 8-11 | 6-9 | 10-13 | 5-8 | 5-8 | |
| -45μm ≤/% | / | / | / | 8.0 | 5.0 | 5.0 | 8.0 | 5.0 | 5.0 | ||
| Setting Time | Initial Setting Time (min) | ≥45 | ≥60 | ≥90 | 120-180 | 30-90 | 180-240 | 150-210 | 30-90 | 90-150 | |
| Final Setting Time (min) | ≤360 | ≤360 | ≤360 | 150-240 | 90-180 | 240-330 | 210-300 | 90-180 | 270-360 | ||
| Strength (ISO) | Flexural Strength/Mpa | 24h | 6.0 | 6.5 | 8.0 | 7.5-10.0 | 8.0-10.5 | 8.0-10.5 | 8.5-11.0 | 5.0-7.5 | 5.0-7.5 |
| 72h | 7.0 | 7.5 | 10.0 | 10.0-12.0 | 10.5-12.5 | 10.5-12.5 | 11.0-12.5 | 6.0-8.5 | 6.0-8.5 | ||
| Compressive Strength/Mpa | 24h | 45 | 55 | 72 | 40-50 | 45-55 | 45-55 | 50-60 | 30-40 | 30-40 | |
| 72h | 55 | 65 | 82 | 45-55 | 50-60 | 50-60 | 55-65 | 40-50 | 40-50 | ||
| 325M ≤/% | 15 | 12 | 8 | / | / | / | / | / | / | ||
| Specific Surface Areas ≥/ (㎡/kg) | 300 | 320 | 350 | / | / | / | / | / | / | ||
Early cement hardening releases a lot of heat. Compared with Portland cement of the same grade, it can release 70-80% of the total heat of hydration in only one day. Due to several heat releases, it is suitable for concrete works with low temperature curing.
the cement stone structure of high alumina cement is dense, the main component is low calcium aluminate, and the content of calcium oxide is very small. During the hydration process, free calcium hydroxide is not precipitated but aluminum hydroxide gel is formed. A protective film is formed on the particle surface. It is more suitable for projects with high requirements for resistance to sulfate corrosion.
It will always maintain a solid state in a high temperature environment, and the strength of the cement will not change. High alumina cement can be used as a cementing material for heat-resistant concrete and configured into heat-resistant concrete.
Its early strength increase rate is far higher than that of rapid hardening Portland cement, which is suitable for emergency repair projects, but its strength will decrease later, and its use in structural engineering is limited.
High alumina refractory cement is often used in the production of refractory components in the construction industry, such as refractory bricks, refractory boards, refractory castables, etc. It can be used in the flue, furnace, heat treatment furnace and other parts of the building to provide high temperature resistance and chemical corrosion resistance.
High-alumina refractory cement is often used in high-temperature equipment in the metallurgical industry, such as blast furnaces, converters, electric furnaces, etc. It can be used as a lining material to protect equipment structures from damage caused by high temperature and chemical attack.
In the petrochemical industry, high-alumina refractory cement is widely used in the lining and protective layer of high-temperature equipment such as oil refining units, chemical furnaces and reactors. It can withstand the high temperature and corrosiveness of petroleum products and chemicals.
High-alumina refractory cement is used in the power industry for maintenance and protection of high-temperature equipment such as electric furnaces, boilers and chimneys. It can withstand high temperature combustion and flue gas corrosion, prolonging the service life of the equipment.
In the glass industry, high-alumina refractory cement is often used as the inner lining and protective layer of glass furnaces, which can withstand the impact and corrosion of high-temperature glass liquid.
High alumina refractory cement is used in the iron and steel industry for maintenance and protection of high-temperature equipment such as ladles, ladles, steelmaking furnaces and continuous casting equipment.
Kerui Group has a number of international certifications, such as, ISO9001/ISO14001/OHSAS18001/CE/SGS. Besides, Kerui’s products also have many domestic certificates, the quality is very guaranteed, and they have been unanimously recognized by customers at home and abroad.
Kerui has a professional quality inspection laboratory. High temperature reheating/load softening creep test furnace;Compressive/flexural strength testing bench for refractory materials; Composition testing and inspection platform for refractory materials; Laboratory for physical/chemical properties for refractory materials.
The entire delivery process is tracked, and Kerui’s expert team solves specific project needs with the utmost professionalism. If the customer’s project requires it, Kerui’s expert team will go to the customer’s country to provide face-to-face technical support.
Besides mainland China, Kerui Refractory has exported products to more than 50 countries and regions across 5 continents across the world, including Asia, Europe, America, Africa and Oceania. We have received recognition and high praise from customers all over the world, and are constantly receiving customers’ return orders and referrals.