Analysis of impurities of Nd-Fe-B magnet by nuclear method and recovery by precipitation chemical of Nd and Pr rare earths

الملخص EN

The products of the new information and communication technologies (NTIC), whose life often not exceed three years, became consumables to the computer image and other waste that contains neodymium and praseodymium (rare earths).

In this field of analysis of impurities, treatment and recycling of waste, we propose the recovery of elements such as neodymium and praseodymium, from the super-magnet Nd-Fe-B, Our study provides a simple process and inexpensive.

The implementation scheme of our project consists in a first step in developing a plan of experience that has been made specifically to perform the optimization of operating conditions of the precipitation process.

This experimental design was inspired by a statistical technique advanced design of experiments known factorial design.

The flow sheet processing of recovery begins by embrittlement in liquid nitrogen (-196C) followed by dissolution in an acidic solution and precipitation of Nd as neodymium oxalate.

For characterization we used the following techniques: The neutron radiography, the neutron activation analysis (NAA), the scanning electron microscope coupled with EDX and XRD.

The counting of γ spectrum shows that the purity of the precipitate is higher than 99%.

Then, the thermal decomposition transforms this powder to neodymium oxide.

After the reduction we obtain pure neodymium.