In large-volume environments, like in the iron ore industry, any time savings that can be made in the laboratory, without a loss in accuracy and precision, result in higher sample throughput and faster turnaround times for fast-moving commodities Integration of the revolutionary ED core into the Zetium spectrometer combines two technologies, namely WD- and EDXRF, to a unique and powerful analytical heart called SumXcore technology. This delivers unique benefits for mining and metals applications, such as:
- Reduced measurement times
- Identification and flagging of unexpected elements in production
- Fast sample screening
- Spectrum archiving
This data sheet demonstrates the time savings achieved with SumXcore technology for the analysis of iron ores by XRF.
Instrumentation and software
Measurements were performed using a Zetium XRF spectrometer configured with 4 kW Rh anode, SST R-mAX X-ray tube, the WD core, which is made up of the appropriate collimators, crystals and detectors for WDXRF analysis, and the ED core, which is a fixed EDXRF detector capable of capturing a complete EDXRF spectrum simultaneously to WDXRF measurements. All measurements were conducted using the state-of-the-art SuperQ software package.
19 commercially available iron ore standards were fused into 40 mm glass beads in an Eagon 2 bead fusion machine and used to set up calibrations for the 16 oxides shown in Table 1.
One application was set up using the optimum combination of both technologies where certain elements were reported on the WD core and others on the ED core. This was done without compromising the analytical requirement for accuracy and precision. The measurement times for this combination were compared to a classical WD-core-only setup and are provided in Table 2.
Table 1 contains the calibration details for the application. Calibration RMS and K factors are shown depending on the technology used to report results.
To determine the optimum combination, a comparison between the WD core and ED core was made for all elements of interest. As an example of this a comparison is shown for SiO2 in Figure 1 which graphically depicts the comparison between the calculated silica (SiO2) concentrations derived from the WD core and the ED core measurements for all standards used to set up the application. This process was repeated resulting in a application where 9 compounds were measured using the WD core and 7 compounds were measured using the ED core.
Table 1. Calibration results
Significant time savings
The ability to measure multiple elements with the ED core, while individual elements are measured on the WD core results in a 37 % time saving for every measurement, as shown in Table 2. This equates to a sample throughput increase of approximately 106 to 161 samples per 8-hour shift at continuous operation (including sample loading time). In this case, the majority of saved time comes from the reduction in measurement time, however, there is a small contribution from the reduction in overhead time (i.e. the time required to change crystals, collimators filters, etc. in WD core channels). The overhead time can become a significant contributor, especially when large numbers of elements are being measured with widely varying conditions on the WD core.
Accuracy and precision
Table 3 demonstrates the achievable accuracy and precision (repeatability) of the combined application when measuring a certified iron ore standard JSS 830-3. The results presented confirm the accuracy of the combined application, delivering concentration values close to the certified values. It can also be seen that the application delivers consistent results, with excellent repeatability values.
SumXcore technology benefits:
- Reduce analysis times by up to 50 %
- Identify and flag unexpected elements
- Rapid sample screening
- Spectrum archiving
Figure 1. WD core vs. ED core calculated SiO2 concentrations
Table 2. Measurement times for the WD core and SumXcore applications
Table 3. Accuracy and precision of the SumXcore application (JSS 830-3)
The results clearly demonstrate that the combination of WD- and EDXRF incorporated in the Zetium spectrometer delivers faster measurement times than only one technology for the analysis of iron ores as fused beads. This increase in speed is achieved without a loss in analytical performance and the stability of the Zetium spectrometer ensures repeatability close to the theoretical limit. These two factors allow improved sample throughput, which is highly desirable in high-volume industries like iron ore. The inclusion of the ED core also allows for other advantages, such as fast sample screening, with or without Omnian standardless analysis software,and unexpected element identification and flagging in process control.