Iron ore mining companies are obliged to assure the quality of their analytical results because chemical measurements support important decisions in production and commercial areas.
Sample preparation by fusion combined with X-ray fluorescence (XRF) has already shown to be essential for the determination of major elements in iron ores. Since the analytical results may be affected by a large number of factors inherent to the Fusion-XRF analytical process, internal quality control procedures must be adopted to monitor the validity of tests and calibrations undertaken.
All iron ore laboratories regularly run XRF drift corrections and quality control samples. However, bias contribution from the fusion technique, fusion positions, fluxer to fluxer and mould effects are difficult to assess and quantify. Claisse fusion monitors are introduced as a novel quality control tool to quantify and validate the correction of biases related to the fusion process.
Fusion MonitorTM consists of homogeneous and pre-fused beads, each composed of a lithium borate flux, a non-wetting agent and an iron ore. Independent from the sample preparation step, Fusion Monitor is ready to be fused directly from the bottle, allowing the assessment and validation of the biases between the fluxer positions, the different fusion instruments, and also between the fusion platinum moulds.
The use of Fusion Monitor is based on comparison. The measurement obtained from a given Fusion Monitor preparation is compared to a reference value that was obtained by the preparation of the same Fusion Monitor specimens under an initial set of conditions (fusion time, platinum mould, fusion instrument, fluxer’s position, etc.). Finally, examining the Fusion Monitor results for patterns and trends provide the laboratory analyst with much valuable data to recognise and solve pending problems before the Fusion-XRF analytical process become unusable.
The laboratory analyst now has three complementary quality control tools to monitor the entire Fusion-XRF analytical process:
- The XRF drift monitors to assess and correct XRF calibration drifts
- The Claisse® Fusion Monitor to assess and correct fusion process biases
- Control samples to assess and correct sample preparation errors
Using Fusion Monitor on a day-to-day basis allows the laboratory analyst to take a proactive approach to monitoring the fusion process, minimise the Fusion-XRF analytical process downtime and maintain consistency of the analytical results.