The proposed conceptual flowsheet for high REEs recovery from spent NdFeB magnets.
Due to their remarkable magnetic properties, such as a high maximum energy product, high remanence, and high coercivity, NdFeB magnets are used in a variety of technological applications. Because of their very limited recycling, high numbers of spent NdFeB magnets are widely available in the market. In addition to China’s monopoly on the supply of most rare earth elements, there is a need for the recovery of these critical metals, as their high import price poses an economic and environmental challenge for manufacturers. This paper proposes a pyrometallurgical recycling method for end-of-life NdFeB magnets by oxidizing them in air as first required step. The main goal of this method is to oxidize rare earth elements from NdFeB magnets in order to prepare them for the carbothermic reduction. The experimental conditions, such as the oxidation temperature and time, were studied in order to establish the phase transformation during oxidation using the Factsage Database and experimental conditions. Our thermogravimetric analysis TGA analysis revealed an increased sample mass by 35% between room temperature and 1100 °C, which is very close to the total calculated theoretical value of oxygen (36.8% for all elements, and only 3.6% for rare earth elements REE), confirming the complete oxidation of the material. The obtained quantitative analysis of the oxidation product, in (%), demonstrated values of 53.41 Fe2O3, 10.37 Fe3O4; 16.45 NdFeO3; 0.45 Nd2O3, 1.28 Dy2O3, 1.07 Pr2O3, and 5.22 α-Fe.
Abstract This study aimed at investigating the perceptions of children attending preschool education about protecting the environment through drawings. This study was carried out with a qualitative research method. The study group of this study consisted of 80 children among 48-60-month-old children attending preschool education in Nicosia, Turkish Republic of Northern Cyprus (TRNC). In this study, the children were requested to explain their thoughts through drawings by asking the following question: “What can be done to protect the environment?” Then, the children were asked to describe their drawings orally. The descriptions of children were recorded in writing and analyzed. As a result of the analysis, it was determined that the most common perception about protecting the environment was “not littering”. In addition to this, it was determined that the children had different perceptions as “not wasting water”, “not polluting nature”, “not starting a fire”, “not polluting the sea”, and “not cutting the trees”. It was concluded that the children had a perception of protecting the environment only from these aspects with the drawings that included reduce and respect dimensions of the 7R model. It was also concluded that they did not have a perception in the dimensions of reuse, rethink, reflect, recycle, and redistribute.
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