We combined two different x-ray based techniques in a new on-line analyser for slurries. The technology operates directly on-stream for plant control and monitoring.
Finding minerals in slurries
Examining slurries for minerals requires specialised analytical instrumentation.
The minerals industry has traditionally relied on two x-ray-based technologies to determine a material's characteristics: X-ray fluorescence (XRF) and X-ray diffraction (XRD).
XRF slurry analysis provides sensitive chemical composition analysis.
XRD slurry analysis is a more general tool, capable of measuring a wide range of minerals in both slurries and dry powders.
These different approaches give different information on the slurry composition but require two separate systems, creating greater complexity and expense.
New analyser cuts complexity
We combined the best aspects of the XRF and the XRD systems into a single unit, which we called the XRDF.
The XRDF is capable of measuring both mineralogy and ultra-low elemental composition directly on a process-stream, analysing material in slurry form, without the need for labour-intensive, time-consuming and potentially error-prone sampling.
By using 'launder tank' geometry, a wide range of flow rates, up to 100 litres per minute, can be accommodated. It also reports on analysis every minute allowing rapid response for more reactive plant control.
Detecting elements at parts-per-billion levels
This development has created a detection system and a compact unit providing simultaneous mineralogical and elemental analysis which nearly halves the cost and complexity of slurry analysis.
The development team considers this system to be a big leap in slurry analysis providing up to 10 times more sensitivity than other commercial slurry analysers.
It can detect down to a level of about 100 parts-per-billion, allowing us to measure valuable metals such as gold, silver, uranium and the platinum group elements, which may only be present at levels of a few grams per tonne or less.