Image detectors for online mineral liberation analysis

Mineral liberation is one of the key parameters driving the effectiveness of valuable material extraction. On-line analysis of the liberation is a challenging task requiring the characterisation of mineral particles at the micrometer level. A reliable on-line measurement of mineral liberation is yet to be successfully resolved. A device capable of measuring mineral liberation on-line would be a world's first. Recently, semiconductor pixel detectors, originally designed for applications in high energy physics, have become available for other scientific, medical and industrial applications. These detectors offer exceptionally good spatial resolution, single particle counting, unlimited dynamic range and other advantages. Their properties are opening up the possibility to apply them to on-line mineral liberation measurement. This work used the Medipix2 detector to measure the X-ray uorescent energy of samples to determine elements present and by analysing the spectra in each pixel, spatial information of the elements in the sample are also obtained. One of the major drawbacks using a pixel detector in this manner is the issue of charge sharing and a unique method to compensate for this problem is also presented. The results of this work are extremely promising with both simple and complicated samples returning identification of minerals down to the 110x110 um size.