Hedge fund Elliott Associates and Jane Street Global Trading are suing the London Metal Exchange for up to $500 million after the LME cancelled nickel trades on March 8 when prices soared to record highs above $100,000 a tonne in chaotic trade.
India has raised its basic import duty on gold to 12.5% from 7.5% as the world's second biggest consumer of the precious metal tries to dampen demand and bring down the trade deficit.
Deep-sea mining would involve using heavy machinery to suck up off the ocean floor nodules that contain cobalt, manganese, and other rare metals mostly used in batteries.