Automated Mineralogy for Cement Production
New technologies for new building materials - characterizing material blends to lower costs and reduce CO2 emissions
Cement is crushed, naturally-occurring, limestone that has been heated to high temperatures in a kiln, and is typically used to bind natural or man-made aggregates together to form durable building materials such as concrete. The process that occurs within the kiln produces a product known as clinker which has four main components – alite, belite, aluminate, and ferrites – all of which contribute to the strength and hardening properties of cement once crushed to a fine powder and mixed with water.
Cement producers use Automated Mineralogy to trouble-shoot production problems on cement plants, help improve the quality of their products, and investigate on-site construction issues. Typical mineralogical data that the Built Environment industry needs from cement products include: the proportions of alite vs belite phases on a size-by-size basis; the micro-texture of the alite and belite; nature and amount of trace impurities, such as unburnt lime, clays and silica.
In an attempt to address environmental and economic issues surrounding cement production, manufacturers are now using clinker replacement materials such as blast furnace slag, fly ash, volcanic ash, kaolinite, and various pigments. This practice reduces the overall amount of cement required to produce the end product, which in turn reduces CO2 emissions, and also uses up waste materials that would otherwise be problematic to dispose of. However, careful analysis is required today, more than ever, of these new products, to ensure quality and performance, and FEI is working with cement companies to provide them with the necessary materials characterization capability. FEI's analytical Scanning Electron Microscopes (SEM), and Automated Mineralogy Solutions, MLA and QEMSCAN®, are enabling cement manufacturers to characterize products that are more environmentally friendly than those made in the past.