IM 2016 September 2016 | Page 161

MARINE MINING
The new MV SS Nujoma for Debmarine Namibia at its launch in Norway in January
prototype with associated launch and recovery equipment , which will be used to perform field tests at four EU minesites . SMD is the Technical Manager on the ¡ VAMOS ! project which is a consortium also funded by the European Union ’ s Horizon 2020 research and innovation programme . The team are developing a submerged mining solution to exploit existing inland mines which are no longer economically viable by conventional mining methods . The programme will develop processes and technology , such as mining navigation , sensing and awareness systems , to be exploited in this new and emerging market .
An evaluation of all acquired data will be taken into account in the selection process of test sites , with testing due to take place from mid-2017 .
Another key partner is UMS , which is jointly owned by Denith Engineering and ADP Marine and Modular . Members of the UMS team were largely responsible for the underwater crawlers and shallow water sampling systems – utilised for diamond mining off the west coast of Southern Africa . ADP brings mineral processing capability to the partnership .
The project includes integrated robotic systems in the air , on land , on the water and underwater . Technology wise it includes positioning , navigation , awareness , automated multi-robot cooperation , and distributed navigation systems .
The project will see the consortium build prototype equipment and test it at four submerged ore deposits : tin / tungsten in northern Portugal ; copper in southern Portugal ; iron in Bosnia Herzegovina ; and an alluvial deposit in UK . The trials will involve a range of rock types , with a variety of rock strengths and at a variety of water depths . Already in April this year , the team investigated the chosen site in Bosnia , where “ questions , and possible issues were being raised with regard to the foreseen testing activities as well as the interest of inland submerged mining for opportunities for future development of mining in the region . Next , the currently abandoned mine site itself was investigated , to asses specific circumstances and to obtain as much data as possible needed to prepare any future trial , to validate the design of
the equipment with regard to the mine site requirements , and to asses possible risks and associated suitable mitigation measures .”
Also in April , a second ¡ VAMOS ! stakeholder workshop took place in São Domingos , a village located in the south of Portugal , close to the Spanish border . The future of abandoned mines of the Iberian Pyrite Belt was the topic of this workshop , which collected the views and insight of local and regional stakeholders from Portugal and Spain on possible development scenarios linked to the reopening , in the future , of some of the old mines of the region .
¡ VAMOS ! runs from February 2015 to July 2018 and has a budget of € 12.4 million and funding of € 9.2 million . The system will include a Modular Launch and Recovery Vessel , dewatering facilities , HROV and underwater mining vehicle . It will use wireless short range high bandwith comms to connect the HROV , mining prototype , HROV docking station and LARV , with the mining equipment powered by an umbilical . It will also have real time grade control using a gated spectrometer and will use multiple sensory sources , allowing remote operation at night and in turbid water . Options include nearshore alluvial mining and options to go beyond the reach of a standard dredging vessel as well as the possibility of underwater onshore mining of kimberlites pipes with better wall stability and reduced stripping ratio , no toe seepage , water pressure balanced across the pit wall and no weakening due to blast vibration and over-break . Run of mine ore is suitably sized to bypass primary crushers and there are no haul-roads required , with reduced access maintenance , improved safety and robotic control with no workers in the pit . It is cheaper to pump as opposed to hauling and there is no dust as this is wet mining , no blast fumes , no blast vibration , no blast noise and no fleet noise . There is also no mine discharge – as water is returned to the pit to maintain operability , and no lowering of the local water table .
The method has a lower carbon footprint ( lower energy requirements per tonne and lower tonnes mined due to stripping ratio advantage ) and lower visual impact . The
The ¡ VAMOS ! project opens up more opportunities for onshore mining from flooded pits , even of kimberlite pipes consortium says it has been enabled by improvements in cutter technology , developments in underwater robotics , and improved positioning , navigation and awareness technologies as well as more accurate slurry circuit control technology .
Another vessel for Debmarine
Marine mining of diamonds is the most advanced form currently being conducted . Debmarine Namibia ’ s new N $ 2.3 billion ( US $ 139 million ) diamond sampling and exploration vessel , the MV SS Nujoma , was launched in January at the Kleven Verft AS shipyard in Ulsteinvik in Norway .
The 12,000 t vessel slid down the slipway into the water ahead of schedule on January 9 to the applause of the ship owner , shipbuilders and the Ulsteinvik community .
The SS Nujoma , named after the Founding President and Father of the Namibian nation , Dr Sam Shafiishuna Nujoma , is the first of its kind and incorporates a range of innovative technologies .
Debmarine Namibia is recruiting Namibian skilled and licensed seamen who will undergo training prior to the vessel handover . The second part of this project , the subsea sampling system and treatment plant , has been developed in parallel by De Beers Marine South Africa and will be installed on the SS Nujoma in the Port of Cape Town in the second half of 2016 .
The vessel , which has a helicopter deck suitable for Sikorsky S61s , is diesel electric powered and can accommodate up to 80 crew . It is the most advanced marine diamond sampling and exploration vessel in the world and will be the sixth in the Debmarine Namibia fleet . It is scheduled to start commissioning in Namibian waters in the first half of 2017 .
Debmarine Namibia was established in January 2002 and mines in the offshore mining licence area off the southern coast of Namibia at water depths of up to 140 m . The company employs 800 people , 75 % of them seagoing . Its other vessels are Debmar Atlantic , Debmar Pacific , Gariep , Grand Banks and Mafuta . IM
SEPTEMBER 2016 | International Mining 159