Influence of high temperature degaussing on lifting capacity of linear motor reciprocating pump

The submersible linear motor reciprocating pump is a new type of artificial lift. The degaussing effect of its permanent magnet at high temperature will reduce the lifting capacity of the linear motor reciprocating pump. In this paper, the thermal stability of NdFeB permanent magnet material was studied by simulating the underground temperature and pressure conditions in a high-temperature and high-pressure reactor and combining with a Tesla instrument. The results show that NdFeB material loses its magnetism rapidly at high temperature, and the residual magnetism is proportional to the ambient temperature of the magnet. The high temperature demagnetization effect of large magnets is more serious due to eddy current loss and hysteresis loss.

Hydrometallurgical Recovery of Rare Earth Elements from NdFeB Permanent Magnet Scrap: A Review

NdFeB permanent magnet scrap is regarded as an important secondary resource which contains rare earth elements (REEs) such as Nd, Pr and Dy. Recovering these valuable REEs from the NdFeB permanent magnet scrap not only increases economic potential, but it also helps to reduce problems relating to disposal and the environment. Hydrometallurgical routes are considered to be the primary choice for recovering the REEs because of higher REEs recovery and its application to all types of magnet compositions. In this paper, the authors firstly reviewed the chemical and physical properties of NdFeB permanent magnet scrap, and then carried out an in-depth discussion on a variety of hydrometallurgical processes for recovering REEs from the NdFeB permanent magnet scrap. The methods mainly included selective leaching or complete leaching processes followed by precipitation, solvent extraction or ionic liquids extraction processes. Particular attention is devoted to the specific technical challenge that emerges in the hydrometallurgical recovery of REEs from NdFeB permanent magnet scrap and to the corresponding potential measures for improving REEs recovery by promoting the processing efficiency. This summarized review will be useful for researchers who are developing processes for recovering REEs from NdFeB permanent magnet scrap.

PENGARUH DIMENSI MAGNET PERMANEN NdFeB DAN JARAK CELAH UDARA TERHADAP KINERJA GENERATOR MAGNET PERMANEN FLUKS AKSIAL SATU FASA

The purpose of this research is to know the influence of NdFeB permanent magnet dimensions and the distance of air gap on performance of single phase axial flux permanent magnet generator. In this research using quantitative approach with experimental method. Research subjects used, namely permanent magnetic generator axial flux with two rotor samples that have different magnetic dimensions and conducted air gap variation. The research data was collected by testing without load and testing with electrical load, to know the performance values of the generator in the form of induction voltage and electric power. The results showed that the induction voltage and electric power were affected by the magnetic dimensions and the distance of the air gap. These results indicate that the rotor with a magnetic surface area of 0.0058 m2 and 0.0034 m2 produces an induced voltage of 91.7 and 27.1 V, as well as a power of 14 and 2.8 W. Whereas, for variations in the air gap with the rotor magnetic surface area 0.0058 m2 and varied 2; 3; 4; 5; and 6 mm produces an induced voltage of 91.7; 89.0; 86.5; 80.2; and 68.5 V, and power of 14; 12; 10.9; 10.5; and 8.8 W. Thus, the use of a magnet ic dimension that is larger and in accordance with the size of the coil, as well as the use of a small air gap distance will result in a better induction voltage value. Abstrak Tujuan dari penelitian ini adalah untuk mengetahui pengaruh dimensi magnet permanen NdFeB dan jarak celah udara terhadap kinerja generator magnet permanen fluks aksial satu fasa. Pada penelitian ini menggunakan pendekatan kuantitatif dengan metode eksperimen. Subjek penelitian yang digunakan, yaitu generator magnet permanen fluks aksial dengan dua sampel rotor yang memiliki dimensi magnet berbeda dan dilakukan variasi celah udara. Pengumpulan data penelitian dilakukan dengan pengujian tanpa beban dan pengujian dengan beban listrik, untuk mengetahui nilai-nilai kinerja generator berupa tegangan induksi dan daya listriknya. Hasil penelitian menunjukkan bahwa tegangan induksi dan daya listrik dipengaruh oleh dimensi magnet dan jarak celah udara. Hasil tersebut menunjukkan bahwa pada rotor dengan luas permukaan magnet 0,0058 m2 dan 0,0034 m2 menghasilkan tegangan induksi sebesar 91,7 dan 27,1 V, serta daya sebesar 14 dan 2,8 W. Sedangkan, pada variasi celah udara dengan rotor luas permukaan magnet 0,0058 m2 dan divariasi 2; 3; 4; 5; dan 6 mm menghasilkan tegangan induksi sebesar 91.7; 89.0; 86.5; 80.2; dan 68.5 V, serta daya sebe sar 14; 12; 10,9; 10,5; dan 8,8 W. Maka, penggunaan dimensi magnet yang lebih besar dan sesuai dengan ukuran kumparan, serta penggunaan jarak celah udara yang kecil akan menghasilkan nilai tegangan induksi yang lebih baik.