Technology: Wave machine seeks to mine the depths

日期:2019-02-28 08:12:06 作者:缪邗 阅读:

By ROGER MILNE A SWEDISH company is planning to harness wave power to extract minerals from sea water. Following the success of a laboratory-scale device, the Gothenburg-based company Sea Power is seeking tenders for a pilot plant which it hopes will demonstrate the technique commercially and technically next summer. The heart of the system is a wave machine, essentially a series of basins mounted on a floating pontoon anchored at sea. Water pressure in the basins, which act like funnels, is used to drive turbines and generate electricity. The turbines are connected to pumps which suck up the water from the deeper layers underneath the pontoon. This water is led through sorbent felt mats which concentrate the mineral ions present. These are extracted by electrolysis, utilising some of the power produced by the waves. The process is based on work developed by Goran Lagstrom, a Swedish inventor. Originally, the system was envisaged as a neat way of ‘mining’ the ocean for uranium oxide. This is present at concentrations of 3.3 parts per billion in sea water. But a glut of uranium stocks, coupled with a downturn in prospects for nuclear power, has switched the scheme in another direction. Now the intention is to use the system to recover rare and expensive minerals also present in sea water, including aluminium, scandium, vanadium, chrome, magnesium, cobalt, irridium and cerium. Full-scale versions of the device are planned weighing up to 200,