Nickel/metal hydride batteries can be partially reclaimed today through pyrometallurgical processing, although the focus is primarily on the nickel, chromium and iron fractions. Rare earths and other metals typically contained in the hydride alloy are not separated and form part of a slag that is eventually sold as aggregate for road construction. The principal facility of this type in the U.S. that accepts Ni/MH battery waste is operated by INMETCO. A variety of wastes from the stainless steel industry have been processed in rotary hearth and electric arc furnaces by INMETCO to produce a standard remelt alloy that can be used by stainless steel producers. Nickel/metal hydride batteries are compatible with the INMETCO process due to their high nickel and iron content. Because batteries are only a fraction of the waste stream, the amount of battery waste that is available is not important to continued operation of the process. This recycling process is thus well suited to the current period of uncertainty while EV/HEVs establish a foothold in the market. At present levels of waste generation, there is no fee levied to process Ni/MH scrap, but none of the inherent value is returned to the waste generator, either.
In Europe, S.N.A.M. has developed several processes to separate and recycle AB5 hydride alloy from Ni/MH batteries . One process separates 60 to 85 percent of the hydride alloy for reuse in batteries, while the remainder and other metalic components are recycled as nickel-iron scrap. Another simpler process deactivates the hydride alloy and the residue can then be sold for production of nickel or nickel-cobalt alloy.
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