A newly-developed concept for mining manganese nodules from water depths of up to 6000 metres has been announced by Aker Wirth. The German company worked with the German Federal Institute for Geosciences and Natural Resources (GBR) for three years to develop the concept of targeting the large deposits of ores and precious high-tech metals including manganese, cobalt, nickel and copper located in deep seas.

The two companies also examined the concept for its profitability, commissioning the German Federal Ministry of Economics and Technology to undertake the study.

“The increasing scarcity of resources coupled with the continuous rise in resource prices drive the search for new raw material deposits. As a result, the deep sea is coming increasingly under the spotlight,” says Aker Wirth’s vice president of technology and innovation Steffen Knodt.

“The extreme deep-sea conditions including enormous water pressure, ice-cold temperatures and complete darkness present huge financial and technical challenges to the mining industry when extracting these materials. Aker Wirth has recognized the potential of this important future market early on and advances the development of relevant products,” he says.

The new system consists of two manganese nodule collectors, a transport system for conveying the material, and a specially-designed production vessel. A continuous transportation of raw material from the collectors via rises that are several kilometres in length is required to ensure efficient mining. At such water depths, this places considerable demands on the robustness of the single components as well as on the control unit for the complete system.

Aker Wirth has met these challenges by using its experience as a partner to mining, oil and gas customers where it has supplied drilling systems for the extraction of diamonds from the seabed since the 1990s.

The company’s environmentally-friendly air-lift technology will transport manganese nodules to the drilling vessel. This technology has demonstrated its capabilities in numerous projects for the exploration of oil and gas reserves at great depths.

Steffen Knodt says the economic study concluded deep sea mining is a lucrative venture after analysing the entire process chain from the collecting of manganese nodules to the transport of materials and through to land-based processing. “At present, efforts are being made at an international level to first of all establish the regulations regarding mining of manganese nodules, which will then serve as a basis for the development of mining and transport systems. As a consequence, the mining of manganese nodules will probably reach an industrial scale in five to 10 years.”

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