The IGF project 17397 N of VDZ gGmbH is supported by the AiF within the framework of Industrial Collective Research (IGF) of the Federal Ministry of Economic Affairs and Energy on the basis of a decision of the German Bundestag.
Use of quantitative X-ray diffraction analysis in cement quality control
With a view to reducing CO2 emissions the cement industry is producing more and more cements with several main constituents. For production and quality inspection it is essential to be able to determine the quality and standard conformity of these cements. If used in an expert manner, quantitative X-ray diffraction analysis is capable of determining the clinker phases and the cement composition. Automation of the evaluation process is however required for cement production. At the same time, though, it must be ensured that there is no significant loss of quality in the analyses. Questions remain about reproducibility, the influence of production fluctuations and the quantification of cements with several partly amorphous main constituents. Finally it would be desirable to have a sufficiently accurate automatable method to supplement or even replace reference tests as part of factory production control and third-party inspection.
The research project initially involved a sequence of steps to formulate robust, automated preparation methods and evaluation files and determine their reproducibility. This meant having to use a preparation module corresponding to those of the plant laboratories. The use of a variety of factory and laboratory cements of a known composition made it possible to define the precision of the X-ray analytical method and thus also the limits of its applicability. The effects of unavoidable production fluctuations associated with industrial scale processes on automated evaluation were also described for laboratory cements with varying raw materials and constituents with differing fineness of grinding. Concluding plant tests were performed to verify the applicability of the analysis system to practical use.