Gold Mineralogy

SGS is the world’s leading metallurgical testing firm with an exemplary understanding of gold mineralogy. The mineralogists and metallurgists at SGS have extensive experience in gold mineralogy from exploration to production and across a variety of unit operations. Depending on your needs, we can bring the power of High Definition Mineralogy to your questions and get detailed, accurate results.

Gold Characterization and Deportment

Gold deportment studies include pre-concentration of gold and heavy minerals in the sample using heavy liquids followed by superpanning of the heavy liquid gravity concentrate. Products are submitted for chemical analysis and examined by optical or instrumental analysis.  Concentration of the precious metals determines the number of polished sections required.  On average, 20 grains per sample are submitted for electron microprobe or Quantitative Evaluation of Materials by Scanning Electron Microscopy (QEMSCAN) analyses.

Submicroscopic Gold by Secondary Ion Mass Spectrometry (SIMS)

The extractive metallurgy of gold and silver is controlled and often complicated by mineralogical factors such as the locking of submicroscopic gold in sulfide mineral structures. Understanding the deportment of gold locked in pyrite, arsenopyrite or other minerals in either gold ores or mill products is critical to troubleshooting low gold recovery.  Secondary ion mass spectrometry (SIMS) is an important tool in investigating refractory gold balances because of its unique ability to detect and map submicroscopic gold in carrier minerals.

Gold Balance

SGS has the ability to quantify the presence of microscopic and submicroscopic gold in a sample and combine this data to generate a gold balance.  This quantifies free milling and refractory gold contents for:

• Conceptual scoping studies
• Flowsheet development 
• Pre-feasibility testing and piloting
• Process audits
• Process troubleshooting

To determine the character of refractory gold and a mass balance between refractory and free-milling gold in a sample, a sequence of separations and analyses are performed. While the protocol is complex, the sizing, pre-concentration and final concentration steps are crucial to yielding a sample large enough to be both statistically valid and still able to quantify the gold present in the sample. Gravity, flotation and cyanidation are used on the various sulfide minerals. A sample size of 0.5 - 5 kg is required for the analysis of 25 grains.

SGS is the industry leader in High Definition Mineralogy for the global minerals industry and other market sectors that need detailed material, product or residue characterizations. SGS mineralogy experts ensure a quality product and, from grassroots exploration to production support, provide significant interpretive value.