Estimation of blastfurnace slag in blended cement by X-ray diffractometry

A rapid and accurate method has been developed for estimation of blastfurnace slag (BFS) contents in blended cement by X-ray diffraction (XRD) analysis, based on the ratio between the XRD pulse counts of the cement sample at 20, 30·6 and 22·5 (Cu-K_a). This XRD ratio is found to have an almost linear relationship with the quantity of BFS in the cement. A single set of reference samples may be used for estimation of BFS from different sources, provided both sets have similar physico-chemical characteristics. However, reference samples containing slag from the same source as in the blend improve the accuracy. This method avoids the assumptions or personal judgement involved in some other methods.