The Analysis of Mining Effluents – A Suitable Application for TXRF

Mining activities are likely to produce effluents in large quantities rom different sources. These may be drainage from mine workings, seepage and run-off from tailings impoundments or dry trailing piles, seepage and tailings from waste rock and spent ore dumps, as well as run-off from disturbed areas. Effluents may contain harmful substances and therefore can be a potential hazard to surface and ground water. It is therefore of great importance to control these effluents and analyze them regarding metal content.

The Bruker S2 PICOFOX total reflection X-ray fluorescence (TXRF) spectrometer was used to analyze both simulated effluents (spiked solutions) and real-world effluents from different mines in South America to test its suitability for this type of analysis. As effluents may contain a range of metals in different concentrations, the S2 PICOFOX’s capability of simultaneous multi-element trace analysis was seen as a major advantage for this type of measurement.  In combination with the high speed of analysis and the sample changer, it is a promising candidate for rapid sample screening.

As such measurements are usually carried out with wet chemical analysis methods like Coulometry, Atomic Absorption Spectroscopy, Inductively Coupled Plasma (ICP), it made sense to compare with at least one of these methods. ICP-MS (Mass Spectrometry) was chosen for this purpose.

The analytical results show that the determination of a large portion of the sought after substances is possible. TXRF can therefore be seen as a suitable tool for small mines with restricted space and analytical capabilities to test their effluents. The S2 PICOFOX is portable, has a small footprint and requires only a power outlet, consumables, like gases, are not needed. Although not a complete replacement for standard-conform methods, it provides valuable services in fast and highly sensitive pre-screening of samples. A presentation of measurement procedures and analytical results can be downloaded from here.