Methods of Analyzing Results
- An energy-dispersive (EDS) detector is used to separate the characteristic x-rays of different elements into an energy spectrum, and EDS system software is used to analyze the energy spectrum in order to determine the abundance of specific elements. EDS can be used to find the chemical composition of materials down to a spot size of a few microns, and to create element composition maps over a much broader raster area. Together, these capabilities provide fundamental compositional information for a wide variety of materials.
How Does EDS Work?
- Typically integrated into either an SEM or EPMA instrument.
- Include a sensitive x-ray detector, a liquid nitrogen dewar for cooling, and software to collect and analyze energy spectra.
- Contains a crystal that absorbs the energy of incoming x-rays by ionization, yielding free electrons in the crystal that become conductive and produce an electrical charge bias.
Results
- A typical EDS spectrum is portrayed as a plot of x-ray counts vs. energy (in keV). Energy peaks correspond to the various elements in the sample. Generally they are narrow and readily resolved, but many elements yield multiple peaks. For example, iron commonly shows strong Kα and Kβ peaks. Elements in low abundance will generate x-ray peaks that may not be resolvable from the background radiation.
| Raw Fe2O3 Grade % | Beneficiated Fe2O3 Grade % | Initial Raw Fe2O3 Kg | Beneficiated Fe2O3 Kg | Mass % (Fe: 69.94% ) | P50% Efficiency Potential recovery of Pure Fe Kg |
|---|---|---|---|---|---|
| 30 | 70 | 100 | 70 | 48.958 | 24.479 |
Therefore potential for recovery of pure iron from tailings is approximately 25%