June/July 2008

Potential new technology for Canadian lake-based mining

South African firm explores adapting existing underwater crawler technology


MMP launching crawler in Africa

A South African-based firm of marine engineers, Marine and Mineral Projects (MMP), is currently researching the possibility of adapting their existing underwater crawler technology — currently being used by De Beers for marine diamond mining — for lake-based mining applications in Canada.

According to Rodney Norman, the managing director of MMP, the idea is still very much in its infancy and the company still needs to research it in depth, looking at various aspects such as the environment, geology, climate, position of each mine, viability and so forth.

“We believe that it may be fairly simple to develop and enhance our current marine diamond mining technology to mine the bottom of a lake without having to drain the water,” said Norman. “This would mean no longer having to build huge dykes at vast expense or having to disrupt a lake’s ecosystem. Currently, as we understand it, the mining of lake-based deposits involves the construction of massive concrete and stone dykes around the site. The area of lake within the dykes is then pumped dry to allow access to the lakebed.”

In other instances, entire lakes are drained to access the mineral-rich deposits hidden beneath their depths.  An example of this is Steep Rock Lake in northwestern Ontario, which required the dewatering of the lake (which had a surface area of over 13 square kilometres), the diversion of a major river system, the lowering of nearby Finlayson Lake by 12 metres, and the largest dredging project ever to be undertaken in Canada.

“Understandably,” said Norman, “the process of building these huge dykes and/or draining the lake is vastly expensive and time-consuming, plus this method of mining has a fairly large environmental impact on the area while the mine is in operation, with additional expense to rehabilitate an area once mining activities have ceased.”

MMP’s current marine technology consists of a 240-tonne, remote-operated underwater crawler that is equipped to cut into the ocean bed and vacuum up the diamondiferous material, which is then pumped to the plant through a 650 millimetre internal diameter rubber hose using a 2.4 MW pumping system. A 500 KW hydraulic power pack powers the systems on the crawler.

“The crawler is controlled by a pilot and a co-pilot who scrutinize its progress through a system of 12 computer monitors that provide readings on oil and water levels, pressures and temperatures,” explained Norman. “Plus, the pilots see a virtual animation of the movements of the crawler, the seabed and the mining process.”

According to Norman, one crawler unit is capable of extracting approximately four million tonnes of product a year. “We asked ourselves if it is possible to mine the bottom of the ocean with this technology, then why not the bottom of a lake,” said Norman. “Any lake-based deposits can potentially be mined using the crawler technology, so this adaptation possibly applies to uranium, zinc, gold, copper, nickel and so on.”

Although Norman reiterated that this project is still very much just an idea at this stage and requires more research to take it further, he said that MMP is very excited by the prospect, as it has the potential to greatly assist and enhance the industry.

Post a comment


PDF Version