Cement, Energy & Environment Jan-Mar 2002

! TECHNOLOGY TREND PUSHING THE LIMITS The importance of reliable trace-element analysis in environmental, geological and industrial applications is increasing, particularly with stricter worldwide legislations for controlling pollution. The hardware is already available in the form of state-of-the-art analytical instruments such as Philips Analytical's MagiX family of XRF spech·ometers which are capable ofmeasuring elemental concentrations down to O.lppm. Pro-Trace can calculate net intensities in trace– element analysis based on a series of advanced algorithms for accurate background determination and corrections for ma trix effects, special overlap and low-level spectral impuri ties. Background correction for fixed channels in simultaneous spectrometers can also be achieved with the equipment. As part of the SuperQ platform, Pro-Trace also shares its graphical user interface, and a smart element selector for important trace-element suites, including pre-defined measuring procedures. Comprehensive.online help with worked examples is also available. For details contact: as below Courtesy: World Cement Dec. 2001, P 8, Enquiry no:2 E-mail :mail@worldcement.com web : www.worldcement.com HIGH ALUMINA RENAISSANCE Michael Clark A recent conference on calcium aluminate cements attrac ted a notable number of delegates from the cement industry. With representatives ranging from companies such as Lafarge and Heidelberger through to ACC and Cimsa, this month's Technical Forum looks a t the growing interest in this speciality product. After a closer inspection, Dr Clark reports on why there is more to this discredited building material than first meets the eye. The key aspect of the hydration of calcium aluminate cements is that initially a metastable hydrate is formed: • CA + lOH ---+ CAH 10 This metas.table hydrate eventually converts into a stable calcium aluminate hydrate and hydrated alumina: • 3CAH 10 ---+ C 3 AH 6 + 2AH 3 + 18H There ar~ a number of applications where the unique properties of calcium aluminate cements are better suited than ordinary Portland cements and these are the source of the growing market for the material Perhaps the most interesting applications are in the fields of 'building chemistry' where the cements find application in self-levelling floor screeds and concrete repair materials. Courtesy: International Cement Review_ fan . 2002, P 57. E-mail: info@CemNet.co.uk Web: wwW.CemNet.com REFRACTORY REMEDIES ICR Research Refractories are an essential part of cement plants fulfilling several vital functions. Suppliers are manufacturing ever more complex heat resistant materials to cater for 23