Sounds like a bonzer idea to me:
The company, Marine Minerals, said the project would only go ahead if the tin could be \”extracted\” – it rejects the idea that it will be \”dredging\” – in an environmentally and socially responsible way.
Its proposal is to suck the sand up from the seabed — between 200m and 1km out – to a depth of up to around 2m and sift it at sea. The portion containing tin, estimated at around 5%, would be taken back to shore and milled, while the other 95% would be returned to the seabed at once.
Marine Minerals is aiming to sift 2m tonnes of sand a year and says there is roughly a billion tonnes of sand in total in the area it wants to work in.
Not entirely sure how they\’ll \”sift\” that sand at sea though. The ore they\’re after is cassiterite and you usually use gravity to separate that out from the other pieces of the sand. It\’s not magnetic, so you can\’t use magnetic separation.
Hmm. Well, the gravity separation you use is usually in water…..think those troughs to separate out the gold you see in every western movie. I suppose that could be done in sea water, on site. Mebbe.
The company argues that the project, which would not begin before 2015, will create skilled jobs, help meet a growing global demand for tin and could help develop a technology that could be used in other parts of the world, including south-east Asia, where much more intrusive methods of extraction cause damage to marine habitats.
And that last is most definitely true. If they can get the technology to work then it would indeed be a good one.