Tungsten plays a large and indispensable role in modern high-tech industry. Up to 500,000 tons of raw tungsten ore are mined each year by Wolfram Bergbau und Hütten AG (WHB) in Felbertal, Austria, which is the largest scheelite deposit in Europe.
Since the beginning of the mining operation in 1976, the head grade has decreased from 0.7 % down to about 0.2 % today, whereas the economic operation of the processing plant requires 0.3 %.
On the basis of plenty of pilot tests on site, the company decided to install TOMRA sensor-based sorting technology to increase the production benefits.
In 2008, TOMRA Sorting GmbH delivered a sorting machine with X-ray transmission sensors to pre-sort scheelite and made the elimination of waste in large quantities possible. The customer was satisfied with the operation results and bought a second machine with X-ray transmission sensors in 2012.
“This solution was a milestone. The result is a greater concentration of tungsten from the same run of mine,” explained mine manager Felix Gaul. “Now much less material needs to be ground and ﬂoated. That saves energy, chemicals and water.”
More than 100,000 tons per year do not need to be processed and disposed as ﬁne tailings into settling ponds with limited capacity. The XRT-sorted waste rock can instead be sold as aggregates for road construction.
Since Wolfram Bergbau und Hütten AG was entering a complete new area of technology, the company was highly concerned with the issue of trust. The security fostered by having knowledgeable and experienced engineers on hand strengthened that sense of trust. “It has always been a pleasure working with the TOMRA Sorting team,” said Felix Gaul.