Renewables’ deep-sea mining conundrum 

Posted: April 14, 2017 by oldbrew in exploration, Geology

Deep sea mining for rare earth minerals [image credit: BBC News]

To what extent do ‘renewables’ depend on finding sources of non-renewables? Mining is involved – the raw materials have to be found and extracted from the earth.

British scientists exploring an underwater mountain in the Atlantic Ocean have discovered a treasure trove of rare minerals, reports BBC News.

Their investigation of a seamount more than 500km (300 miles) from the Canary Islands has revealed a crust of “astonishingly rich” rock. Samples brought back to the surface contain the scarce substance tellurium in concentrations 50,000 times higher than in deposits on land.

Tellurium is used in a type of advanced solar panel, so the discovery raises a difficult question about whether the push for renewable energy may encourage mining of the seabed. The rocks also contain what are called rare earth elements that are used in wind turbines and electronics.

Energy implications

Known as Tropic Seamount, the mountain stands about 3,000m tall – about the size of one of the middle-ranging Alpine summits – with a large plateau at its top, lying about 1,000m below the ocean surface.

Using robotic submarines, researchers from the UK’s National Oceanography Centre found that the crust is dark and fine-grained and stretches in a layer roughly 4cm thick over the entire surface of the mountain.

Dr Bram Murton, the leader of the expedition, told the BBC that he had been expecting to find abundant minerals on the seamount but not in such concentrations. “These crusts are astonishingly rich and that’s what makes these rocks so incredibly special and valuable from a resource perspective.”

He has calculated that the 2,670 tonnes of tellurium on this single seamount represents one-twelfth of the world’s total supply. And Dr Murton has come up with a hypothetical estimate that if the entire deposit could be extracted and used to make solar panels, it could meet 65% of the UK’s electricity demand.

He says he is not advocating deep-sea mining, which has yet to start anywhere in the world and is likely to be highly controversial because of the damage it could cause to the marine environment.

But Dr Murton does want his team’s discovery, part of a major research project called MarineE-Tech, to trigger a debate about where vital resources should come from.

“If we need green energy supplies, then we need the raw materials to make the devices that produce the energy so, yes, the raw materials have to come from somewhere.

“We either dig them up from the ground and make a very large hole or dig them from the seabed and make a comparatively smaller hole.

“It’s a dilemma for society – nothing we do comes without a cost.”

Scientists are now weighing up the relative risks and merits of mining on land as opposed to on the seabed.

Full report: Renewables’ deep-sea mining conundrum – BBC News

  1. tom0mason says:

    Typical anti-progress thinking.
    Man has progressed for at least the last 43,000 years in part from his abilities in mining and digging (see Man is the mining Ape!
    As a part of nature man has survive and flourished partly because of his natural ability in toolmaking, and to mine for the resources he requires for this task.
    This find should be exploited but done efficiently and with due consideration for the surrounding fauna & flora.

  2. JB says:

    “Demand” is the operative word (like antiques, there is no real value without buyers), but more importantly, has anyone seriously looked into the number of sun days during the Little Ice Age? What kind of weather are we expecting to have during the next grand solar minimum?

    I still think Sir Hoyle was basically right when he published his energy analysis, Energy or Extinction, in 1977. Of course at that time it was not so widely known the earth makes petroleum and gas as part of the geological processes driven by the solar flux. Fred assumed there was a finite amount of petroleum to be extracted, based on the ridiculous notion it all came from from decaying organics.

    Instead of focusing on these exotic forms of energy conversion using rare elements, wouldn’t it make more sense to establish how a solar minimum (it’s going to get COLD) will impact the production of our existing resources? Coal and thorium are still in plentiful supply…..

  3. oldbrew says:

    China may spend quite a lot on renewables but is also into coal gasification.

    Coal is utilized in three ways in China: direct combustion (through coal-fired power plants and industrial boilers), coking, and gasification. Among these three methods, coal gasification is the cleanest option, and the most complex. Coal gasification accounts for 5% of China’s total coal consumption

  4. Gamecock says:

    “These crusts are astonishingly rich and that’s what makes these rocks so incredibly special and valuable from a resource perspective.”

    Tellurium trades at about 17USD/pound.

    Yawn. Not particularly incredibly special and valuable.

  5. AlecM says:

    Rare earths and some fissile materials are not particularly rare. Thus thorium is present in large quantities in the rare earth ores. It is also 99% fissile compared with 0.7% for uranium ores.

  6. Curious George says:

    AlecM’s numbers are rather unconventional.

  7. BoyfromTottenham says:

    I loved the comment “…if the entire deposit could be extracted and used to make solar panels, it could meet 65% of the UK’s electricity demand”. a clever insertion of disinformation that makes the reader think that solar panels in the UK could ‘meet 65%’ of the UK’s ‘energy’ demand. Energy demand is not the same as electricity demand, and solar panels are hugely inefficient in the UK and of course only work when the sun shines. But I guess the average BBC reader would swallow it whole.

  8. Richard111 says:

    Doesn’t matter how efficient solar panels and wind turbines are, they don’t work under heavy snow.

  9. oldbrew says:

    Richard – to state the obvious, solar panels don’t work after dark either, and do very little under grey skies in northern latitudes. They seem to be on their last legs in the UK.

    Date: 14/04/17 The Independent

  10. AlecM says:

    @curious george: [use a breeder reactor to change high stability, 99% Th 232 via U233 to Th 233 which is fissile] [U238 is 99.28%, U235 is most of the rest]

  11. Curious George says:

    Alec, thanks. 99% of Uranium is U238 which can be converted to fissile products in a breeder reactor.

  12. Gamecock says:

    Thorium is not fissile.