Automated Mineralogy System

What is the Automated Mineralogy System?

An automated mineralogy system combines a scanning electron microscope with energy-dispersive spectrometry and software to map minerals on polished sections. It quantifies mineral abundance, grain size, association and liberation by size class, supporting circuit design and plant diagnosis.

Overview

Polished resin blocks are coated with carbon and scanned in the electron microscope. At each measurement point the energy-dispersive spectrometer records a spectrum, and classification rules assign the point to a mineral or to a group such as mixed spectrum, which is then resolved statistically. Stitching thousands of points produces mineral maps from which the software calculates modal mineralogy, grain size distributions, mineral association coefficients and degree of liberation by size class. Measurement spacing is selected according to grain size: finer spacing improves resolution but increases run time, so a microscopy session for one sample can range from twenty minutes to several hours. The value of the technique lies in linking assays to texture, which explains recoveries in flotation, gravity and magnetic separation circuits and identifies locked or refractory material for further study.

How does it work?

Each technique answers a different question. X-ray diffraction measures the angles at which a crystalline sample diffracts a monochromatic beam; lattice spacings follow Bragg's law, and the resulting pattern identifies phases, with peak intensities refined to give approximate weight fractions. Automated mineralogy combines a scanning electron microscope with energy-dispersive spectrometry, acquiring element maps of polished sections and converting them into mineral classifications, from which abundance, grain size, association and liberation are calculated. X-ray fluorescence excites a pressed or fused sample and measures the fluorescent radiation of each element, giving concentrations from major to trace levels after matrix correction. Density separation compares a sample's behaviour in a liquid of known specific gravity, which indicates mineral composition and washability. Magnetic separation tests quantify the fraction that is recoverable by magnetic separation, which matters for magnetite ores and for removing iron-bearing gangue.

What are the key features?

• Scanning electron microscope with energy-dispersive spectrometer
• Automated stage and beam control for large area mapping
• Classification rules for mineral identification
• Mineral association and liberation calculations by size class
• Modal mineralogy and grain size reporting
• Polished section preparation with carbon coating

What are the technical specifications?

A typical automated mineralogy system configuration offers accelerating voltage of 15–25 kV, detector of Energy-dispersive X-ray spectrometer, measurement spacing of 1–20 µm selectable, sample format of Polished resin block, 25–50 mm, analysis time per sample of 20 min to 6 h depending on spacing and minimum grain size resolved of About 1–2 µm. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Automated Mineralogy System is used in liberation analysis for flotation and gravity circuits, ore texture and association studies, diagnosis of losses in plant surveys and refractory and locked mineral identification. Across the wider Mineral Analysis class, laboratories also deploy it for ore and concentrate phase identification, elemental assay including penalty elements and mineral liberation and texture analysis.

Which standards and certifications apply?

Relevant standards and methods include ISO 9516-1, ISO 11535, ISO 3082, ASTM E877, ISO 13320 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Sample preparation dominates data quality in mineral analysis. Diffraction needs a fine, randomly oriented powder, so back-loading, side-loading or spray drying is used to avoid preferred orientation, and grinding must not alter soft phases. X-ray fluorescence needs consistent particle size, binder and pressing pressure, or fused beads prepared with a suitable flux; calibration is then built from certified reference materials that bracket the sample range. Automated mineralogy relies on well-polished, carbon-coated sections and on a mineral list and classification rules that match the deposit, so the scheme should be documented and validated against assay data. Heavy liquids used in density separation are hazardous and need fume extraction, splash protection and safe disposal. Instruments require stable power, temperature control and regular performance checks with reference standards.

How do I select the right Automated Mineralogy System?

Select an automated mineralogy system when texture, association and liberation drive your decisions, as in flotation or plant surveys. Specify resolution and spacing needs, sample preparation support, classification software and the reporting formats your studies require.

How does it compare with other Mineral Analysis variants?

Choose the technique by the question, not by habit. Bulk element concentrations, including penalty elements, are best determined by X-ray fluorescence with pressed powders for speed or fused beads for accuracy. Phase identification and quantification require X-ray diffraction, which is also used to follow alteration and to check grinding products for unwanted phases. Where the texture matters, that is, how grains are associated and how well the valuable mineral is liberated, automated mineralogy is the appropriate tool, since bulk assays cannot reveal locking. Physical tests such as density separation and magnetic separation are used to predict processing behaviour and to build washability or recovery curves. Laboratories often combine techniques: X-ray diffraction to identify what is present, X-ray fluorescence to quantify elements, and automated mineralogy to explain why a flotation or magnetic separation result was achieved.