Full Cycle Resource Evaluation of SMS Deposits Along the Arctic Mid Ocean Ridge
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2017-06-25 |
| Authors | Steinar LĆøve Ellefmo, Martin Ludvigsen, Erik Kristian Thon Frimanslund |
| Institutions | Norwegian University of Science and Technology |
| Citations | 3 |
Abstract
Section titled āAbstractāSeveral hydrothermal vent sites have been discovered along the portion of the Arctic Mid-Ocean Ridge (AMOR) inside the extended Norwegian continental shelf (NCS). Seafloor massive sulfide (SMS) deposits are associated with these hydrothermal vent sites. These deposits contain significant amounts of valuable metals, such as copper, zinc, gold, and silver. Lokiās Castle is one of the most promising sites along the AMOR, with two 20-30 m high and 100 m wide mound-shaped SMS deposits. It is located at a water depth of 2,400 m. A production system concept is proposed for a deep-sea mining operation at Lokiās Castle based on the Nautilus Mineralsā Solwara 1 project. The overall cost structure and design of the Nautilusā concept is in this study regarded feasible in AMOR in spite of the difference between the operating environment for the two locations. As the only relevant operational experience is De Beersā shallow-water diamond mining off the coast of South Africa and Namibia, most of the environmental criteria used are taken from offshore drilling. Based on the net operating time, and accounting for scheduled maintenance and waiting-on-weather time, an estimate for annual average production rate and an annual production volume are estimated. Significant downtime is expected in January and July. Significant uncertainties are associated with early phases of projects. Probabilistic cost, grade and price estimates allow dealing quantitatively with uncertainties by giving input variables as probability distributions. Monte Carlo simulations are in this study run for different sets of variables, and the resulting key performance indicators are given as distributions. This paper adapts and presents a methodology normally used to assess technological and economic feasibilities of oil and gas projects. The methodology is adapted to the assessment of deep-sea mining projects and is illustrated through the assessment of the case based on Lokiās Castle ore characteristics and technologies planned for the Solwara 1 project with a cost structure adjusted according to AMOR conditions. Costs for processing, refining, waste disposal and logistics after ore arrival at onshore port is not included. The ore uncertainties are huge and the resources are with the present deposit knowledge speculative. Therefore, this study do not attempt to define any reserves.