Application reports from Rigaku Corporation on cement and cement raw meal analysis

Cement raw meal analysis by pressed powder method on the ZSX Primus III+

Rigaku Corporation has published an application report on the Rigaku ZSX Primus III+ wavelength dispersive X-ray fluorescence (WDXRF) spectrometer. Rigaku Application Note XRF 5006 addresses quantitative analysis for cement raw meal by the pressed powder method, including details for sample preparation, method calibration and repeatability.

Because of the nature of raw meal and the challenges it presents to chemical analysis, WDXRF has become a prevalent analytical technique in cement plants.

The pressed powder method is the most common sample preparation technique in X-ray fluorescence (XRF) because it does not require an expensive flux, a fusion machine, or highly trained operators. The report demonstrates that cement raw meal samples can be routinely analysed by the pressed powder method with excellent accuracy and precision on the Rigaku ZSX Primus III+ WDXRF spectrometer.

Measurements were performed on the ZSX Primus III+ with a 3 kW Rh-target X-ray tube. The ZSX Primus III+ is a tube-above sequential WDXRF spectrometer optimised for routine analyses in powder sample analysis. The RX25 multilayer analysing crystal, included in the standard configuration, has high sensitivity for Mg and Na and is capable of eliminating higher-order lines such as Ca-Ka-3rd, which would interfere with Mg-Ka.

The tube-above optics, programmable vacuum speed and powder trap of the ZSX Primus III+ enable secure analysis of powder samples and low frequency of maintenance by preventing pressed pellet samples from breaking and falling, and by protecting the vacuum pump and magnetic valves from fine particles scattered from samples.

For this analysis, one of the reference materials used for the calibration was measured consecutively 10 times to demonstrate the performance and short-term stability of the instrument. On the ZSX Primus III+, a sample is evacuated in the pre-evacuation chamber and then transported into the measurement position. During the measurement cycle of one sample, the next sample to be analysed can be loaded into the pre-evacuation chamber, which reduces the analysis time and prevents contamination of the optical main chamber.

The results show that cement raw meal samples can be routinely analysed with simple sample preparation and high accuracy and precision on the ZSX Primus III+ by the pressed powder method.

A copy of this application report may be requested here.

Cement analysis by the fusion method on Benchtop WDXRF Supermini200 according to ASTM C114-11

An application report on the chemical analysis of hydraulic cements is also available. Application Note XRF5046 demonstrates quantitative analysis for Portland and aluminate cements by the fusion method according to ASTM C114-11 on the Rigaku Supermini200. This is a benchtop sequential wavelength dispersive XRF spectrometer configured for high sensitivity and equipped with a newly developed high-power air-cooled X-ray tube that does not require cooling water. The report covers sample preparation, method calibration and repeatability.

Different types of hydraulic cement with various physical properties are produced by changing the composition of clinker minerals. It is therefore important to control the chemical composition of cement and interim products.

ASTM C114-11 covers chemical analysis of hydraulic cements. In this standard test method, procedures of wet chemical analysis are described utilising X-ray fluorescence (XRF) spectrometry as a ‘rapid test method’.

XRF spectrometry by the fusion method has been the method of choice in cement production processes, due in part to its simple sample preparation and high precision. The fusion technique involves dissolving a sample in a solvent and producing a homogeneous glass bead. Since the fusion method can eliminate sample heterogeneity such as grain size and mineralogical effects, it is possible to obtain high accuracy for cement samples and also to establish calibrations using a variety of materials.

As detailed in the application note, nine NIST CRMs (Certified Reference Material) of Portland and alumina cement were used for calibration and qualification testing. The results prove that the analysis method meets the requirements described in ASTM C114-11. The precision obtained by the repeatability test exceeds the requirements defined in the method.

A copy of this application report may be requested here.

Adapted from press release by Louise Fordham

Read the article online at: https://www.worldcement.com/product-news/23072014/application-notes-published-by-rigaku-corporation-68/