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Recovery process of Ni from anode materials of spent Ni-MH batteries and application of the resulting Ni to CH4 dry reforming catalyst were investigated, focusing on availability of Ni. NiO, which formed a solid solution with CoO, was successfully prepared from the waste by a series of chemical processes using aqueous solutions of HCl and NH3. The resulting NiO, which was reduced to Ni0, exhibited excellent CH4 conversion in CH4 dry reforming. Fromresults, it was concluded that the Ni recovered from anode materials of spent Ni-MH batteries was available for CH4 dry reforming catalyst.

The resource recovery of nickel metal from the spent nickel metal hydride (Ni-MH) battery was investigated by using the CH 4 dry reforming, aiming at reusing it as a raw material of the Ni-MH battery. From the results, a compound identified as a single phase of NiO by XRD was successfully prepared from the spent Ni-MH battery by a series of chemical processes using HCl and NH 3 aq. solutions followed by calcinations. The resulting NiO exhibited excellent CH 4 conversion in the CH 4 dry reforming, i.e., the CH 4 conversion higher than 96% continued for 50 h when the flow rates of injection gases were controlled at CH 4 /CO 2 /Ar = 10:10:80 ml·min -1 . Although the XRD pattern revealed the reduction of NiO to Ni 0 and the deposition of carbon after the CH 4 dry reforming, the deposition of carbon could be suppressed by changing the injection gas ratio. The resource recovery of nickel metal was, therefore, concluded to be possible through the CH 4 dry reforming over NiO prepared from the spent Ni-MH battery. Keywords: resource recovery, nickel metal hydride secondary battery, nickel metal, CH 4 dry reforming, nickel-based catalyst.

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