News: AESSEAL ensures efficient operation at Botswana diamond mine

When an operator of some of the richest diamond mines in the world pledged to reduce water consumption by 15%, Rotherham engineering firm, AESSEAL provided a solution using mechanical seal and system technology.

Botswana is home to the mine that is the world's leading producer of diamonds by value and the world's largest running mine by volume.

Essential to their operation are slurry pumps pumping Kimberlite and Iron Silicate. These applications are amongst the most abrasive in the slurry-pumping world.

The packed glands on the pumps need flush water injection at a rate of 60 litres a minute to prevent slurry entering the seal chamber.

Only 10% of the flush water was recoverable from the process and a typical train of five pumps consumed 134 million litres per annum of water from underground water sources. Due to constant extraction over many years, the water table was dropping and the supply was threatened.

The diamond mines are in a dry semi-desert area and operators pledged to reduce water consumption by 10% immediately and 15% in the medium term.

Pipelines from various alternative sources were considered. The most effective, and most extreme, was to build a 600km pipeline from the Okovango delta at a cost of $30m. This could have endangered water levels in the delta, a world heritage site.

The eventual solution was simple. By using modern mechanical seal and system technology, supplied by AESSEAL, the majority of the 134 million litres was saved. The open loop operation (water going straight into the drain) was converted into a closed loop operation, similar to what you can find in a domestic central heating system.

Alan Roddis, Engineering Director of AESSEAL plc said: "Mineral extraction is a multi-billion £, $ and Euro industry for each mining country. The returns from a profitable mine can be staggering. However, despite these returns, it should be of little surprise that in some parts of the world, little thought is given to the environmental impact that mineral mining creates.

"This is a simple example of the operational inefficiencies that are present in some of the mines around the world"

With global headquarters in Templeborough, AESSEAL is the world's fourth largest mechanical seal business. They specialise in the design and manufacture of mechanical seals, bearing protectors and environmental control systems for process equipment, maximising reliability and protecting the environment from leakage.

AESSEAL website

Images: debswana.com