Flotation is one of the major articles in the November issue of International Mining. Careful ore analysis before designing a flotation plant is important. A new state of the art x-ray imaging detector smaller than a postage stamp is the key to a powerful new method of characterising mineral ores, according to an article published recently in the October issue of CSIRO’s Process magazine. The x-ray, photon-counting imaging device called Medipix can take high resolution images of minerals, detailing the materials present in an ore sample. Unlike conventional x-ray films and cameras, the new technique measures the energy of individual incoming x-rays and adds colour to traditional black-and-white snapshots.Research scientist Dr Josef Uher said the new technique could revolutionise micro-imaging, and the mining industry. “In every single pixel of the detector, you gain information about what the x-ray spectrum looks like. If you analyse it properly, you can determine whether the materials in the sample were nickel, copper, zinc, gold or something else,” Uher said.

Medipix could provide near real-time imaging of ores for plant monitoring and control in the mining industry. It was designed in collaboration with several universities and laboratories led by the European Organisation of Nuclear Research (CERN).

Other stories in this issue of Process include:
• Analysis in extreme environments: Molten salt electrowinning, a key technology used in extractive metallurgy has been analysed using a new x-ray diffraction technique. The new method can be used to monitor changes inside an operating electrowinning cell and can determine electrode performance and extraction efficiency
• Clearing the mist around electrowinning: Examining bubble and acid mist formation during the electrowinning process used for base metal production could provide solutions to manage and reduce the carcinogenic mist. Acid mist poses health risks for workers and current technologies to prevent exposure are expensive
• Ore analysis at light speed: Laser-induced breakdown spectroscopy (LIBS) could provide significant economic savings to the mining industry by accelerating the in situ analysis of ore quality at mine sites.