Page 16 - Bullion World Issue 10 Volume 05 October 2025

Bullion World | Volume 5 | Issue 10 | October 2025 IGC 2025: Where The World Meets India, Seminar Highlights

Technical Session-2
Factors affecting cupellation loss of gold and silver beads from low grade material

Ms Makhosazana Sikhakhane –
Factors Affecting Cupellation Loss

Ms Sikhakhane analyzed variables affecting gold and silver loss
during the cupellation process, essential for refining precious
metals in low-grade materials. Her research focused on process
variables such as temperature, cupel selection, airflow, timing,
alloy composition, and analysis technique, highlighting that silver
is more susceptible to loss than gold due to higher oxidation and
volatilization.

Key Points:
• Cupellation removes base metals, leaving noble metal beads.
• Loss mechanisms include absorption and volatilization.
• Silver more prone to losses than gold.
• Controlled experiments established recovery factors (~99.6% gold, ~96.3% silver).
• Accurate correction factors aid inventory and payment accuracy.
• Highlights need for precise methodology and quality control.

Technical Session-2 Quality Assurance in Gold
Testing Through BNDs (Bharatiya Nirdeshak Dravya)

Mr Dinesh Singh – Quality Assurance Using BNDs

Mr Dinesh Singh presented on the application of Bharatiya
Nirdeshak Dravya (BND) Certified Reference Materials (CRMs)
developed by India’s National Measurement Institute to enhance
the accuracy and reliability of gold assay testing. He explained
how BNDs serve as a vital benchmark for metrological traceability,
ensuring that assay results are consistent, reproducible, and
aligned with global standards. Drawing attention to India’s
capability in producing world-class CRMs, Mr Singh outlined
the meticulous process of material selection, preparation, and
certification that ensures their reliability. He also stressed how
BNDs strengthen consumer confidence, support regulatory
compliance, and provide a competitive edge for India’s gold
industry in the international market.

Key Points:
• Indigenous BND CRMs ensure measurement precision and traceability.
• Comprehensive material selection and certification processes.
• Supports assay accuracy and reduces inter-lab variability.
• Critical for maintaining consumer trust and regulatory compliance.
• Emphasizes maintaining proper ratios and conditions in assay protocols.
• Enhances valuation and standardization in the gold ecosystem.

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