Abstract
Representative measurement of precious metals in bulk materials has been successfully achieved using high performance Prompt Gamma Neutron Activation Analysis (PGNAA). The technique has been proven extensively in various industrial sectors for the multi-elemental measurement of conveyed and packaged bulk materials for over 30 years. The unique capability to measure precious metals directly has occurred over only the last few years with proven performance of GEOSCAN GOLD in gold ores and scrap materials such as e-waste. Measurement of gold content to as low as 0.2 ppm Au and silver to single ppm levels has been implemented at multiple mining operations. Measuring gold and silver along with copper is now also proven in scrap received at recycling plants and in concentrates received by smelters. PGNAA has been successfully implemented for platinum-palladium ore measurement for every thirty seconds of flow for bulk ore sorting applications using measurement of proxy elements. The paper explains the PGNAA technology, its development for gold analysis, and provides examples of applications and performance at multiple operating sites. This capability provides previously unmatched metal accounting opportunities especially when combined with real time moisture analysis for dry tonnage determination.