Source: Edie.Net

Robots: the future of British mining? Imagine an air-tight dome with teams of robots working alongside people in space suits as they sift through the corrosive waste of past generations, looking for scraps of plastic and nuggets of precious metals.

This isn’t the opening scene of the latest Sci-Fi movie to hit our screens, but the vision of one of the leading thinkers of the British waste industry, describing how landfill mining might look a few decades down the line.

Freelance waste consultant Peter Jones, until recently a director at waste giant Biffa, was among the speakers at a London conference looking at likelihood of our old rubbish dumps becoming the mines of the future.

With raw materials becoming increasingly scarce and the price of oil rising it isn’t stretching credibility too far to assume that what we threw away in times of plenty might be seen as a valuable resource in the not-too-distant future.

But is digging up this booty technically and economically feasible, and what will be left after years of decomposition in a hole in the ground?

Mr Jones warned that it might be a while before its safe to unearth these tarnished treasures, describing the grim reality of the rotting mess that remains underground for years after a landfill is capped and the fields above landscaped.

“This is not a friendly or benign environment – it’s an extremely corrosive atmosphere,” he said.

“[When you open these things up] you will certainly discover that it’s pretty awful in terms of decomposition.

“We won’t be able to go into any landfill that’s closing today for about 30 years.”

He said the waste would need to be sorted in air-tight domes and those inside would need to wear hazmat suits, or leave the work to machines.

And when it comes to recovering materials, there will be a fairly short list of useful resources left, he said.

Organics will have decomposed – and hopefully the subsequent methane burnt off as fuel – and all but the most inert of metals will be eaten away in the corrosive soup.

But one waste stream of today could still be a major resource tomorrow.

“When you dig up landfills the only recoverable tonnage material is going to be plastics,” said Mr Jones.

And these, he added, would not be found in large sheets but rather shreds of different polymers here and there, making sorting for recycling an almost impossible task.

This still leaves the option of using the oil-based plastics as fuel however, most likely using relatively clean technologies such as gasification rather than simple energy-from-waste incinerators.

In today’s market, the cost of excavating a landfill and re-processing the waste in the hopes of extracting plastics for fuel does not quite stand up – those who try it are likely to break even at best – but existing drivers are already making the prospect more and more attractive as time passes.

Rising landfill gate fees, growing incentives to find low-carbon fuel and pressures on existing resources are all tipping the scales towards landfill mining. More at Edie.Net.

Ze-gen Inc. hosted a ribbon-cutting ceremony July 23 at the facility in New Bedford, Mass. The New Bedford Waste Services LLC plant will use advanced gasification technology to convert waste into synthetic natural gas and electricity. The pilot plant plans to operate for a year. It is permitted to handle up to 1,500 tons per day of municipal solid waste, construction and demolition debris and scrap tires.

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