Friday, May 06, 2005

Breaking Down Ores With Microwaves

I don't necessarily mean to turn this into a general tech blog, but sometimes it happens that way. Dr. Sam Kingman at the University of Nottingham has announced that his method of using microwaves to fracture ore rocks is ready for prime time, according to the Engineer Online. Conventional ore extraction is terribly inefficient, using most of its energy to make noise. Kingman uses microwaves to bombard ores with high energies for very brief durations, inducing thermal stresses that cause the rocks to shatter. This process uses about 1/20th the energy expenditure of conventional breaking machines.
Kingman said the technology would have important environmental implications. ‘Annual world electrical energy consumption is around 14,000 million kWh. Each kWh of energy generated from fossil fuel releases about 1.5kg of CO2 into the atmosphere. If we can save even one per cent of the world’s energy usage, then that’s a lot of CO2.’

But the mining industry is not famed for its environmental credentials, and while it is under pressure to become more sustainable, a far bigger incentive is the need to process more ore more quickly. So a potentially more attractive advantage to the industry is the fact that using microwave comminution valuable mineral particles break away at a coarser size and are therefore easier to recover. ‘When you do an economic analysis, the benefit of getting more metal out of the ground is what’s really attractive to mining firms,’ said Kingman.

Since it's estimated mining operations absorb 5% of the world's electrical generation, that could add up to a lot of savings. Ah, greed. Greed can be good.