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To provide more reliable data, liquidus lines and solidus lines of the Ni-Co-Cu system in the temperature range from 1400 to 1750K were determined by Thermogravimetry-Differential Thermal Analysis (TG-DTA). The liquidus lines and the solidus lines were determined for low Cu and high Ni compositions, for which data were lacking in previous studies. The obtained results can be used to determine the temperature required to melt the metal obtained by reducing waste lithium-ion batteries (LIBs) in the high-temperature metallurgical process of metal recycling from waste LIBs. [ABSTRACT FROM AUTHOR]

A high temperature recycling process of neodymium magnets using B2O3 flux has been reported. However, the B2O3 flux shows a poor fluidity of the slag. For this purpose of solving the problem, present work considers the use of Na2B4O7 with lower viscosity than the B2O3 flux. The phase equilibria for the Nd2O3-Na2B4O7 pseudo binary system was investigated in the temperature range from 1460K to 1780 K. We found that this pseudo-binary system forms the homogeneous melt in the concentration range of from 16 mass％Na2B4O7 to 20 mass％Na2B4O7 and over 55 mass％ Na2B4O7 at 1673 K. Based on the determined this diagram, the feasibility study of the recycling process of the neodymium magnets using Na2B4O7 flux was carried out 20 kg and 100 kg high frequency induction furnace. When neodymium magnets and an EV rotor were melted with Na2B4O7 in a carbon crucible, the rare earth elements of Nd, Pr, Dy and Tb in the magnets and rotor were enriched to the Na2B4O7 slag phase and the iron in the magnets and the rotor were contributed to the Fe-C alloy phase. The oxalate precipitation method was used for the recovered Nd2O3-Na2B4O7 slag, more 99 mass％ purity ratio of RExOy was recovered. [ABSTRACT FROM AUTHOR]