This started out as a Pick Points and just sort of grew. We were talking in the office today about the new emphasis on lithium batteries (being an Explosives Lab inter all we found that they can blow up if handled wrongly – in a series of experiments a long time ago). And so, since we also look at processing, I became curious about where and how the lithium is mined. It turns out that most of it comes from salt lake deposits such as those in Bolivia.
The biggest deposit in the world lies in the Salar de Uyini, which is also the world’s largest salt flat. A quick look through Google Earth,gives the location, with the white in the picture being the salt flat, and not snow. La Paz, the capital of Bolivia is at the top.
The world’s largest lithium deposit is at Salar di Uyuni (Google Earth)
Tthe lithium is found in the crystallized salt, and in the brine that underlies the crust. As the world gears up to demand more, Bolivia is determined to keep as much of the “value added” part of the processing to itself. Thus the intent is that, this year, the state which has already started construction of a plant that will produce around 1,200 tons a year. (The cornerstone was laid in May). This can be expanded to produce some 30,000 tons by 2012.
Unfortunately for those who are expecting electric cars to spring out of the woodwork in the next few years (remembering that the President’s plan calls for 1 million plug-in hybrids by 2015) Mitsubishi estimates that the world will need 500,000 tons per year. The deposit itself holds at least 9 million tons, although the country has, in total, around 73 million tons. To put the current progress in perspective the pilot plant should produce some 40 tons by the end of the year, as it gears up to full production, with the product coming from brine processing. The world supply of lithium itself is considered to be 28.4 million tons, equivalent to 150 million tons of lithium carbonate. In December the price of a ton of lithium had risen from $350 to $3,000, with current consumption of around 84,000 tons of lithium carbonate a year.
There is, however work going on to find alternate minerals to use in the batteries, both to extend the range on one charge (which might get up to 150 miles – depending on the vehicle) and to lower the cost. Of course, if you want a greater range at lower cost, there are always electric motorcycles.
Lithium is also produced from coarse grained igneous rocks called pegmatites, with spodumene being the most common. American mines were in the Carolinas, but closed since brine processing is cheaper than the mining and processing of the hard rock.
Geothermal power plants draw hot brine from underground as a power source, and these brines can contain dissolved minerals. Thus, for example the seven Geothermal plants at the Salton Sea are reported to be able to produce up to 16,000 tons of lithium per year. The facilities are better known as a source of zinc (pdf). However the potential as a source of lithium is becoming increasingly recognized. The process will include the use of nano-filters.