Production of energy saving materials from the waste mixtures of REEs

This work details the procedures and steps for the synthesis of new magnetocaloric materials starting from the outputs generated by recycling for re-use in magnetic refrigeration application. The outputs utilized were a rare earth element-rich product obtained during the hydrometallurgical processing of nickel–metal hydride (NiMH) batteries. This stream contained a mix of rare earth elements (REEs), mainly lanthanum and cerium. After removing some impurities from this feed, especially aluminium, we have used the obtained product in the manufacturing of advanced REEs-based magnetocaloric materials, especially manganites-, orthoferrites-, and REEs-based alloys. The composition of the output from hydrometallurgical processing of NiMH batteries and typical compositions of magnetocaloric materials was determined using inductively coupled plasma-optical emission spectroscopy. The magnetocaloric oxides were successfully synthesized by using conventional solid-state reaction method. Carbothermic and calciothermic reduction methods were used for the synthesis of the as-cast alloy. The X-ray diffraction analysis shows that the magnetocaloric oxides are well crystallized with presence of secondary phases. The effect of temperature on the crystal structure is briefly described

E-waste Management and the Conservation of Geochemical Scarce Resources

Electrical and electronic equipment (EEE) generates very complex waste due to the wide variety of components such as metals, polymers, ceramic materials, and composite elements. In addition, the growing consumption of these devices due to technological development increases the rate they are disposed of. When improperly disposed of, waste electric and electronic equipment (WEEE) may trigger environmental impacts and negative effects on health. Also, the expansion of the electronic industry is based on the extraction of natural resources, some of which are running increasingly scarce. In this scenario, recycling stands as an alternative in the effort to recover economically interesting materials such as metals, which are abundant in waste electric and electronic equipment. This text discusses the current scenario in the electrical and electronic equipment industry and generation of waste electric and electronic equipment considering the implications of resource management and environment, social, and economic impact in this production chain