Urban mining – the new watchword for sourcing rare earth metals?

Recycling metals from scrap – otherwise known as Urban Mining -  is a growing market. In the US, according to the Institute of Scrap Recycling Industries (ISRI) Scrap Yearbook 2012, in 2011, nearly 135 million metric tons of scrap metal, paper, plastic, glass, textiles, rubber and electronics valued at approximately US$100 billion were manufactured by the US scrap recycling industry. This is a growth from around £20 billion in 2002. Metals form the vast majority of recovered scrap, and currently, ferrous scrap is the most recycled material in the US and worldwide. In the US, 74 million metric tons of ferrous scrap was processed by the scrap recycling industry last year while nonferrous scrap made up around one quarter of the total quantity of material recycled. By value nonferrous metal scrap — including precious metal scrap — accounted for nearly 70% of total US scrap recycling industry earnings in 2011.

Until recently, rare earth metals were not part of the market. In May 2011, a report by the UN’s Environment Programme’s International Resource Panel suggested that tellurium and selenium were “rarely recycled, nor are neodymium and dysprosium, used for wind turbine magnets, lanthanum for hybrid vehicle batteries, and gallium used for LEDs.”  

However, following the aftermath of the closing of the Mountain Pass mine in California in 2002 – once the world's dominant producer of rare earth elements – and China’s restrictions on rare earth exports in 2010 and 2011, it has become ever more urgent for companies to find alternative sources for rare earth materials.  In January, The US Department of Energy granted US$120 million to set up a new research centre in Ames, Iowa, to develop new methods of rare earth production. According to one expert, one of these production methods would be recycling. In March, Honda reported that it has established the world’s first process to reuse rare earth metals extracted from nickel-metal hydride batteries to make new batteries for hybrid vehicles. Since April 2012 Honda had been extracting an oxide containing rare earth metals from used nickel-metal hydride batteries at a plant belonging to ferroalloy manufacturer Japan Metals and Chemicals Co. In a new process, involving the application of molten salt electrolysis to this oxide, Honda has succeeded in extracting metallized rare earths that can be used directly as negative-electrode materials in new nickel-metal hydride batteries.

According to Honda, the rare earth metals extracted in this process have a purity of more than 99% which is as high as that of ordinary traded, newly mined rare earth metals. Honda says it will extract rare earth metals not only from nickel-metal hydride batteries but also from other used parts such as hybrid motors and lithium-ion batteries.

Metal Powder Report spoke to John Schoonover, business development manager at Global Tungsten & Powders Corp (GTP). Last September  the company reported that it had greenlighted a plan to remove rare earth metals from fluorescent lamps. GTP’s recycling centre starts up this April and will process materials in which the mercury has already been extracted. According to Schoonover, recycling rare earth metals is essential in what can be a somewhat turbulent market. “In 2011, prices went through the roof and the market was very uncertain,” he explains. “Recently, things have settled down and purchasing rare earth metals from mined sources is more economically viable, but heavier minerals remain expensive to source and recycling them is a definite alternative.”

In August 2012, Molycorp’s Mountain Pass mine recommenced operations. But GTP plans to continue to grow its recycling project over 2013 and into the future. Besides cost, security of supply is an important factor, Schoonover says. “Recycling will insulate use from price fluctuations,” he says.