Cement works | Unistara
Cement works
Cement production plants represent an important challenge, both because of the particular stresses to which the lining is subjected during the production process, and because of the effects that the different fuels used and the raw materials used determine on the refractory.
For this reason, only a correct analysis of the plant and each of its component areas can lead to the determination of the refractory products that guarantee the durability of the lining.
Careful engineering, correct installation methods and the use of top quality refractory products, Insulating materials and anchors make it possible to considerably limit the wear of the refractory lining, avoid negative consequences for carpentry and achieve an effective reduction in energy consumption as well as a reduction in emissions into the atmosphere.
Main products
Unistara’s range of products, specially selected for cement plants, includes, in addition to standard products, a wide range of high-quality accessory products whose importance in the plant’s economy should not be underestimated:
Basic shapes
Magnesite / sintered tabular alumina spinel bricks.
Concrete
Refractory concrete, spray concrete, insulating concrete.
Aluminous shapes
Alumina and silica-alumina bricks in bauxite and andalusite, resistant to alkalis and liquid phases.
Fibrous insulating products
Mats and papers, for expansion joints, gaskets and for insulation of carpentry: Insulfrax, low bio persistence fibers based on calcium silicate-magnesium wool (AES) and classification temperatures up to 1200°C; Isofrax low bio persistence fibers based on magnesium silicates and classification temperatures up to 1400°C.
Non-fibrous insulating products
Insulating bricks in all grades and classes 23 to 32 according to ASTM international classification, high-temperature resistant calcium silicate sheets.
Main services
Unistara designs turnkey linings for new firing lines or the revamping of existing systems. The turnkey formula covers all aspects of engineering, supply of materials, installation of the lining, supply of the preheating diagram, technical assistance and supervision on site during installation and drying. Unistara also offers anti-abrasion linings for areas of the installation subject to heavy mechanical wear.
Installations Gallery
Main parts of the installation
Preheater
The most common problems on the static parts of the preheater are related to chemical aggression caused by alkali, sulphur and chlorine attacks. To counter these problems, Unistara offers a wide range of traditional and alkali resistant refractory bricks and concretes, completing the offer with metal anchors and biosoluble fibres.
Kiln
For the entrance and calcination areas of the rotary kiln, aluminous bricks with low porosity and high mechanical resistance, based on chamotte or bauxite, are used. For more severe applications (build up and alkaline infiltration phenomena) products based on andalusite with SiC and ZrO additives are used. The basic lining is made of bricks with very low impurities, composed of synthetic magnesite and sintered tabular alumina spinel. The transition zones are typically lined with bricks with a high spinel content, while the firing zone is lined with bricks with a medium-low spinel content to promote crust formation. The outlet can be made either with basic or aluminous bricks or with traditional concretes (or Sol Gel bonded) and in some cases with prefabricated shaped concrete.
Grate cooler
Outlet, vault, bull nose, grate side walls and cold part can all be made of concrete of different qualities, both castable and sprayable, both traditional and Sol Gel Bonded. For the walls, the use of high aluminous brick masonry with a bauxitic matrix is preferable.
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