In this section, samples of the mineral raw materials entering the plant, kiln feed samples and raw mill samples are analysed in the XRF instrument after preparation, and the percentages of the main oxides and the minor elements of interest in the sample are determined. Among the most important chemical parameters examined in raw materials and in-process materials are the oxides of calcium (CaO), silicon (SiO2), aluminium (Al2O3), iron (Fe2O3), magnesium (MgO), sulphur (SO3), sodium (Na2O), potassium (K2O) and other constituents required by the process.
The results of XRF analysis play a fundamental role in controlling and monitoring the chemical composition of materials at the various stages of cement production. By controlling the uniformity of the materials entering the kiln as kiln feed, the entry of unwanted materials is prevented, and using these results the composition of the raw materials and kiln feed is examined and, where necessary, the mixing ratio of the raw materials is corrected in order to achieve the desired chemical composition.
One of the most important applications of this analysis in the quality control unit is the calculation of the required material moduli and indices, including the lime saturation factor (LSF), the silica modulus (SIM) and the alumina modulus (ALM). These parameters are used to control the composition of the kiln feed, optimise the burning process and achieve clinker of the desired quality.