Advertorial: VEGA – Robust problem solvers

Robust problem solvers

VEGA radar measuring instruments hold their own in the difficult environment of gold and platinum mining

It can take some time to find the right measuring method for a specific application. Two mine operators in South Africa also found this to be true. A breakthrough in level measurement was finally achieved with 80-GHz radar sensors from VEGA.

Dirt, noise and deposit build-up

The Sibanye Beatrix 4 gold mine is located in the Witwatersrand Basin in Welkom, South Africa, about 240km southwest of Johannesburg. Sibanye Stillwater is one of the 10 largest gold producers and the third largest platinum and palladium producer in the world.

The ore body is accessed from the surface through vertical shafts, sometimes from depths up to 2km below earth’s surface. Dislodged rock is moved underground through quartz veins, using gravity between the different floor levels to transport the material and reduce distances. In one such quartz vein the level of ore has to be accurately measured. The depth of this section of the quartz vein is 55m and the diameter approximately 5m. Of great concern – at least from the point of view of level measurement – is the very humid atmosphere, which leads to heavy deposits on the measuring instrument.

VEGA suggested trying VEGAPULS 69, radar based on 80GHz technology that generates a very narrow beam angle. In the few years it has been on the market, this radar-measuring instrument has proven to be a problem solver in many difficult applications.

VEGA offered to install a VEGAPULS 69 on a trial basis and let the company test it for three months. The radar sensor was installed with a plastic horn antenna and a mounting bracket. It was then calibrated and put into operation. This measuring situation was challenging even for the rugged VEGA sensors.

The impressive result: VEGAPULS 69 measured absolutely reliably even under extreme conditions. For Sibanye, returning the measuring instrument was out of the question; in fact, the company ordered two more sensors from VEGA. These are also now in use in the mine.

Application in flotation cells

Anglo American Platinum (Amplats) also tested a radarmeasuring instrument from VEGA – VEGAPULS 64, the 80-GHz radar level transmitter for liquids, which used in the Upper Group 2 plant in Rustenburg.

The UG2 concentrator at the Waterval Smelter Complex has a capacity of 400 000 tons per month, making it the company’s largest UG2 facility. VEGAPULS 64 was installed in a collection tank that holds the final concentrate.

The now-installed VEGAPULS 64, with its narrow beam angle of 10°, worked perfectly in this environment, delivering a reliable and repeatable echo that provides the basis for an accurate measurement. This, in turn, yields a stable level measurement unaffected by the extreme conditions and the heavy build-up on the upper side of the instrument.