Underwater Mining

M5tec’s engineers have over 7 years experience in this relatively new industry. Our knowledge and know how can help our clients achieve their desired results, be it via consultancy on improving existing designs or full concept into reality projects.

Along with our fabrication partners we are able to offer full turnkey solutions to your subsea/marine mining needs.

Whether your mining for Seafloor Massive Sulphides (SMS) or Polymetallic Nodules we can turn a brief scope of work into a fully functional subsea mining machine.

What are Polymetallic Nodules?

Polymetallic nodules, also called manganese nodules, are rock concentrations on the seafloor which are formed of concentric layers of iron and manganese hydroxides around a core.

Nodules vary in size from tiny particles visible only under a microscope to large pellets more than 20 centimetres across.  However, most nodules are between 5 and 10 cm in diameter, about the size of a potato.  Their surface is generally smooth, sometimes rough and irregular.

The chemical composition of nodules varies according to the kind of manganese minerals and the size and characteristics of the core. Those of greatest economic interest contain manganese, nickel, copper and cobalt. Other constituents include iron, silicon and aluminium, with lesser amounts of calcium, sodium, magnesium, potassium, titanium and barium, along with hydrogen and oxygen.

Nodule growth is one of the slowest of all known geological phenomena, this can be as slow as a centimetre per several million years

Polymetallic nodules were first discovered in 1868 in the Kara Sea, in the Arctic Ocean of Siberia.  During the scientific expeditions of the HMS Challenger (1872–1876), they were found to occur in most oceans of the world.

Nodules of economic interest have been found in the following areas:

  • North central Pacific Ocean
  • Peru Basin in the southeast Pacific
  • Centre of the north Indian Ocean

What are Seafloor Massive Sulfides (SMS)

SMS deposits are formed when hot water coming out of thermal vents on the seabed mixes with the cold seawater, this process deposits high grade minerals on the seafloor.  This process also results in what is known as “black smokers”, these are hydrothermal vents that are commonly found near volcanically active areas where tectonic plates are moving apart under the seabed.

These black smokers are rich with high contents of copper, gold, zinc and silver.  Smokers can take up to hundreds of years to form in this way and do eventually become inactive.

SMS were first discovered in 1979 at 21 degrees north on the East Pacific Rise near Baja, California, and they have since been found in all the world’s oceans.

Deposits of economic interest have been found in the following areas:

  • Kermadec Volcanic Arc
  • Colville Ridge
  • Bismarck Sea
  • Okinawa Trough
  • Lau Basin
  • North Fiji Basin
  • Red Sea