Mining QEMSCAN

Our Advanced Mineralogy Facilities (AMFs) are equipped with a wide variety of tools including QEMSCAN™ systems. Our team of applied and process mineralogists are experienced in the evaluation of ore samples and metallurgical products that are created from a wide variety of commodities.

QEMSCAN is an acronym for Quantitative Evaluation of Materials by Scanning Electron Microscopy, a system that differs from image analysis systems in that it is configured to measure mineralogical variability based on chemistry at the micrometer-scale. QEMSCAN is the most powerful process mineralogical tool currently employed in the minerals industry. Its flexible technology has been successfully employed for diverse commodities such as precious and base metals, mineral sands and industrial minerals. Data generated by the QEMSCAN instrument can help you to make strategic decisions at the acquisition, exploration, feasibility and plant levels.

QEMSCAN can provide:

• Bulk modal analysis
• Particle maps
• Locked and liberated textural analysis
• Size-by-size, mineral-by-mineral chemical assay  
• Trace mineral hunt and search capabilities

Viewing software allows the user to analyze particle maps and determine:

• Grains and particle size
• Shape factor
• Particle type
• Proportion of mineral species present  
• Isolate sub-sets of particles with the creation of particle characteristic screens

QEMSCAN technology can be used for:

• EXPLOMIN™ packages
• Geometallurgical mapping
• Rapid Indicator Mineral Scan (RIMSCAN) for full indicator mineral suite
• Chemical assay by particle or mineral species in each particle
• Mineralogy
• Degree of mineral liberation
• Plant troubleshooting
• Quantification of the mineralogy and textural associations between ore and gangue
• Mineral and metal recovery data (i.e. gross metal values) to predict the response of the ore in a processing circuit when used in conjunction with reconnaissance-style locked cycle or bench scale recovery tests and piloting
• Prioritization of mining blocks according to predicted metal recoveries and calculated metal values
• Plant audits
• Trace mineral searches
• Environmental monitoring

QEMSCAN consists of a base scanning electron microscope, equipped with four light element energy dispersive X-ray detectors, a microanalyser and an electronic processing unit designed by Intellection. QEMSCAN utilizes both the back-scattered electron (BSE) signal intensity as well as an Energy Dispersive X-ray Signal (EDS) at each measurement point. It thus makes no simplifications or assumptions of homogeneity based on the BSE intensity, as many mineral phases show BSE overlap. EDS are used to assign mineral identities to each measurement point by comparing the BSE signal and EDS spectrum against a mineral species identification program (SIP) or database.

Typically 4-5 polished sections (representing 4-5 particle size fractions) are analyzed per sample. The resulting dataset includes information on between 12,000 and 50,000 grains.

Accordingly, if your sample contains just 1% chalcopyrite, the analysis will describe between 120 and 500 grains of chalcopyrite in your sample, not to mention the information on the sulphide and non-sulphide mineralogy which can often be just as important.

QEMSCAN Operational Modes

There are three general types of measurement, those using the linear intercept and those based on particle mapping.

Bulk Mineral Analysis

Bulk Mineral Analysis (BMA) is performed using the linear intercept method, and is used to provide statistically abundant data for mineral identification, speciation, distribution and quantification.

Particle Mapping

Particle mapping modes, including Particle Mineral Analysis (PMA), Specific Mineral Search (SMS) analysis and Trace Mineral Search (TMS) analysis, provide information on spatial relationships of minerals, including liberation and association data and provide a visual representation of mineral textures. The particle mapping modes of measurement also allow for advanced analysis of the minerals of interest, including grade vs. recovery relationships and mineral release curves.

Field Scan

The Field Scan (FS) mode of measurement maps a rock or core chunks sample that has been mounted in the polished section. It collects a chemical spectrum at a set interval within the field of view. Each field of view is then processed offline to produce a low-resolution digital map of the field of view.

Instruments such as the QEMSCAN are mere tools - High Definition Mineralogy is the product. 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.