As the world’s ore reserves deplete, people are turning to a range of solutions to keep up with demand. There’s a new focus on recycling and on closed loop production. ‘Cash for gold’ companies are getting unwanted gold back from the drawers and jewelery boxes of consumers. Councils are investigating landfill mining. Pioneers start-ups in asteroid or lunar mining are taken seriously enough to raise financial backing.
Less positively, mines that were closed because they were too dangerous are re-opened, their owners offering miners more money to work them – the famous Chilean miners were working in these conditions. Thieves stripping cable or pipes for their scrap value is another symptom of the search for metals, with even the odd copper or bronze sculpture going missing from time to time.
I came across another solution recently in the New Scientist – urban mining. It’s a relatively new idea, born out of the hunch that as technology has progressed and cities have grown and changed, there must be all kinds of redundant cabling and piping underneath the streets. These sources of metal have been dubbed ‘comatose’ stocks – reserves of metal that are out of sight in obsolete infrastructure.
Researchers in Sweden have been gathering old and current maps from utility companies and plotting the many networks. In some cities they’ve found that as much as 20% of the city’s pipework is redundant. Their estimate is that there is $630 million of copper alone under Sweden’s cities, with post industrial towns proving more profitable. Considering Britain’s industrial heritage, this should be interesting news.
Identifying the exact location of pipes is difficult and nobody wants to carve up streets and foundations to get the metals out. That needs further research, but it’s happening. Companies are working on 3D mapping technologies to sense and track underground workings, and others have developed ways to strip wiring out without having to dig it up. It’s only a matter of time before somebody starts making a fortune out of the subterranean infrastructure of places like Sheffield or Stoke on Trent.
All of this innovation is business responding to price signals from the markets. It’s what’s supposed to happen as metal stocks deplete, and eventually this sort of metal recycling and recovery will overtake mined ore altogether. Of bigger concern are those resources that can’t be recycled – most notably fossil fuels. There’s still no direct equivalent for oil or natural gas. Given our dependency on them, leaving the transition away from fossil fuels to the markets is a much riskier proposition.