Spectroanalytical method for evaluating the technological elements composition of magnets from computer hard disks.

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Chemistry

Background:

• Hard disk drives (HDs) contain valuable rare-earth elements crucial for electronics.
• Accurate elemental analysis of HD components is essential for recycling and material recovery.
• Developing efficient and green analytical methods for HDs is an ongoing challenge.

Purpose of the Study:

• To develop and optimize an analytical procedure for elemental analysis of hard disk drive magnets.
• To identify the main elements present in actuator and spindle motor magnets.
• To establish a simple, accurate, and green chemistry-compliant method for HD elemental analysis.

Main Methods:

• Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was employed for elemental quantification.
• Samples underwent magnetic removal, grinding, sieving, and acid digestion using block digesters and microwave systems.
• Standard addition and recovery tests were performed to validate method accuracy, complemented by hyperspectral imaging and principal component analysis for Ni layer data.

Main Results:

• An optimized procedure was established: 100 mg of sample, 7 mol/L nitric acid, and a block digester.
• Iron (Fe) was the most abundant element, followed by Neodymium (Nd) and Praseodymium (Pr).
• The developed method demonstrated simplicity, accuracy, and adherence to green chemistry principles.

Conclusions:

• A robust ICP-OES method was successfully developed for elemental analysis of hard disk drive magnets.
• The optimized procedure offers a reliable approach for quantifying key elements like Fe, Nd, and Pr.
• This method provides a greener alternative for the elemental characterization of electronic waste components.