Fluoride Technology for Obtaining Magnetic Materials Based on Nd-Fe-B. Kinetics of Fluorination Processes of Neodymium and Iron Oxides

Sofronov, V. L.; Buynovskiy, A. S.; Makaseev, Yu. N.; Smolkin, P. A.; Ivanov, Zakhar; Ermakova, Ya.V.

doi:10.1016/j.proche.2014.11.028

Cited by 2 publications

(2 citation statements)

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“…In addition, fluorine is one of the most aggressive reagents, which creates certain difficulties in choosing materials and the need to create safe working conditions and reduce environmental pressure on nature. In [32,33], experimental data on the use of elementary fluorine are presented, where some of the above problems were successfully solved. Fluorination with anhydrous HF gas is possible up to a temperature of 1223 K. However, there are also problems with the durability of the equipment materials.…”

Section: Materials and Methods Of Preliminary Analysismentioning

confidence: 99%

“…In addition, Equations ( 1) and ( 2) are reversible, so a large surplus of reagents is needed, which further increases the cost of the process, especially when using elementary fluorine. More widely used ammonium fluorides are fluoride and bifluoride [33]. Ammonium fluorides in the anhydrous state interact with many substances and form ammonium fluorometallates.…”

Section: Materials and Methods Of Preliminary Analysismentioning

confidence: 99%

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Thermodynamic Studies and Optimization of the Method for Obtaining Neodymium Fluoride for the Production of Magnetic Sensors’ Sensitive Elements

Kropachev

Podrezov

Алексахин

et al. 2021

Sensors

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Rare earth metals (REM) with magnetic properties find application in the recently developed high-tech industries. Sensor magnetic systems based on neodymium are increasingly in demand in modern engineering and geological surveys due to their favorable combination of properties of magnetic materials based on rare earth metals. One of the problems is to obtain high-quality materials for the production of such magnetic sensors. It should be noted that the high activity of REM does not allow obtaining master alloys and REM-based alloys from metallic materials; it is advisable to use halide compounds. This work discusses a method for producing neodymium fluoride from its oxide. REM fluorides can be obtained by fluorinating the oxides of these metals. Various fluorine-containing compounds or elemental fluorine are usually used as fluorinating reagents, which have their own advantages and disadvantages. The thermodynamic and technological analysis of neodymium fluoride production processes has shown the most acceptable fluorinating agent is ammonium hydrofluoride, which was used in this work. In order to increase the productivity and degree of chemical transformation, it was proposed to perform heating stepwise; i.e., at the initial stage, heat at a speed of 3 degrees per minute, after which the heating speed was reduced to 2 degrees per minute, and finally the speed was reduced to 1 degree per minute. Due to proposed heating mode, the same productivity and yield of chemical transformation were achieved, with an increased efficiency up to 30%, which can significantly reduce the cost of production. The obtained product is used in the production of neodymium-based alloys by metallothermic reduction of a mixture of fluorides. The sensor material obtained in this way is characterized by a low (less than 0.05%) oxygen content.

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Section: Materials and Methods Of Preliminary Analysismentioning

confidence: 99%

Section: Materials and Methods Of Preliminary Analysismentioning

confidence: 99%