:: A Diamond in Level Measurement

Reliable level measurement under extremely harsh conditions is now possible, thanks to 80 GHz radar level sensors. This article explains how one operator at a diamond ore processing plant was able to gain significant advantages by switching to radar level measurement at 80 GHz.

The dense media separation (DMS) process is a special flotation process in diamond ore processing. Dust and dirt are, among other things, the major factors that adversely affect level measurement in the flotation tank.

The highest diamond mine in the world at 3200 metres above sea level is located in the Maluti Mountains in the Kingdom of Lesotho. The environmental conditions there are correspondingly rough: frequent snowfall, temperatures that fluctuate between -18°C and 20°C and strong winds, which intensify the low temperatures, are part of everyday life.

The conditions in the ore preparation process are also pretty rough. The mine transports the ore to the surface through two kimberlite pipes. These are vertical chimneys of volcanic origin that extend deep into the earth’s crust. The source rock is crushed and further processed to extract diamonds. This whole procedure is extremely laborious. Worldwide production of natural diamonds is now about 20 tonnes per year but covers only about 23% of industrial demand. The rest is industrially manufactured.

The two pipes in the Lesotho mine contain only a very small proportion of diamonds. Their yield is less than two carats per hundred tons of rock and a huge effort is required to get these diamonds. The mine, 70% of which belongs to Gem-Diamonds and 30% to the Lesotho government, processes 5,8 million tonnes of ore per year in two plants. An additional 1,2 million tonnes are mined and processed by a contractor at a separate plant. The combined tonnage produces approximately 100 000 carats per year.

Read the full article here: www.instrumentation.co.za/8932a