Production of Ni-Fe alloy by combined recycling of waste nickel-metal hydride batteries and waste toner powder

Abstract

This paper elucidates a novel and sustainable way of bringing two major sub e-waste streams (waste electrodes of Ni-MH battery and waste toner powder) together to manufacture NiFe alloy. Reduction of oxides (present in the Ni-MH battery electrode) with carbon sourced from waste toner was performed at 1550 degrees C which observed the formation of NiFe alloy as reaction proceeded to 1 h. Percentages of waste toner in the 2 g feed material containing waste electrode mass was varied to study the metal/slag formation and separation alike. The product and slag phases were both analysed by X-ray powder diffraction, Scanning electron microscopy, Energy dispersive x-ray spectroscopy, Laser induced breakdown spectrometer to confirm the formation and metallic composition of the NiFe alloy (>75 % Ni and > 14 % Fe) and the mixture of rare earth oxides present in the slag phase. In addition to manufacturing the metallic alloy, which evinces a possibility of being used as a feedstock in industrial applications, this innovative recycling technique also brings down the burden on landfills.