The rise of counterfeit gold, often doped with elements like Rhenium and Tungsten, poses a serious threat to the gold market. The Maxsell Gold Purity Analyzer offers a reliable solution, accurately detecting these impurities and ensuring the authenticity of gold. By using advanced technology, this gold testing machine safeguards businesses and consumers alike from falling victim to counterfeit gold, making it an essential tool in today’s evolving marketplace.
Maxsell gold purity analyzer detecting gold doped with Rhenium and Tungsten.
The influx of old materials containing rhenium (Re) and tungsten (W) into the gold recycling market has created a significant challenge. Refiners who lack proper detection methods risk substantial financial losses if this contamination goes unnoticed. This article explores the difficulties of identifying rhenium in recycled gold and offers strategies for overcoming them.
The Rhenium Dilemma
The recent surge of recycled materials containing Re and W has disrupted the gold refining industry. These impurities can be tricky to identify, particularly for refiners relying on outdated equipment.
Unearthing Rhenium Contamination
Rhenium contamination in recycled gold can manifest in three primary ways:
- Visibly Impure Materials: In some cases, rhenium is accompanied by visible black dots on the gold’s surface. These samples are readily identifiable during inspection and can be flagged for further testing or rejected altogether.
- Subsurface Impurities: For materials with lower rhenium content, the surface might appear normal despite the presence of rhenium beneath it. X-Ray Fluorescence (XRF) analysis with a larger collimator might miss these hidden traces. Destructive testing methods, such as cutting or melting the sample, are necessary for accurate detection.
- Uneven Distribution: Rhenium distribution within the gold can be highly uneven. Even with XRF analysis, there’s a risk of missing rhenium hotspots if a large collimator is used. A smaller collimator can improve detection sensitivity, but this comes at the cost of longer scanning times.
Choosing the Right Tools for the Job
- Spectrometer Detector: For accurate rhenium detection, a high-resolution detector like Si-PIN or Fast SDD is crucial. Proportional detector instruments lack the resolution needed to reliably identify low rhenium content.
- FP Algorithm: Standard spectrum resolution algorithms can struggle due to interference from other elements like gold and zinc. Utilizing an instrument with a Full-pattern fitting (FP) algorithm offers a more robust solution. FP algorithms achieve better spectral peak separation, leading to more accurate rhenium analysis.
Balancing Detection Efficiency
While smaller collimators enhance rhenium detection sensitivity, they also significantly increase scan times. Refiners should weigh the benefit of more precise rhenium identification against the cost of extended processing times.
Conclusion
Recycled gold containing rhenium presents a challenge for refiners. Careful visual inspection, coupled with XRF analysis using high-resolution detectors and FP algorithms, is essential for accurate rhenium detection. Refiners should also consider the trade-off between detection sensitivity and processing efficiency when choosing a collimator size.
By implementing these strategies, refiners can effectively identify rhenium in recycled gold, minimize losses, and ensure accurate material valuation.
