Mineral Separates for Geochronology and Isotopic Research

Featuring

Electric-Pulse Disaggregation

ODM has been performing mineral extractions from rock and sediment samples since 1974.  Presently, ODM prepares close to 1500 research-grade mineral separates per year for numerous domestic and international universities, analytical laboratories, governments, and mining/mineral exploration companies throughout the world.  ODM's Mineral Extraction Division has also become a world leader in utilizing electric-pulse disaggregation (“EPD”) to provide clean and superior mineral separates.

Mineral Separates

ODM's  full-service mineral processing laboratory prepares a wide range of mineral separates, including:

  • Zircon

  • Apatite

  • Monazite

  • Feldspar

  • Baddeleyite

  • Sericite

  • Illite

  • Biotite

  • Muscovite

  • Hornblende

  • Garnet

  • Sulphides

 

We routinely tailor and modify our processing to: (1) meet your specific requirements; and (2) optimize the quality of any given mineral extraction.

 

For most applications, a disaggregated sample (whether by EPD, mechanical crushing or sediments) is pre-concentrated on a shaking table to produce a low-grade table concentrate.  Most zircon grains are very small (<50 µm) and are extracted from the table concentrate by micropanning.  A zircon-rich pan concentrate is produced at this stage.

 

To extract other minerals, the -1 mm table concentrate is typically refined by heavy liquid (methylene iodide) separation to produce a heavy mineral concentrate (“HMC”).  The density of the heavy liquid can be modified to any specific gravity depending on the targeted mineral.  The HMC can be further refined using one or more of the following methods: (a) ferromagnetic separations; (b) electromagnetic separations; (c) sizing (sieving); (d) friction ramp refining; (e) electromagnetic separations; (f) additional variable-density heavy liquid separations; and (g) hand-picking of mineral grains.

The quality of the mineral separates is monitored by professional geologists/mineralogists and is confirmed by SEM/EDS.

Electric-Pulse Disaggregation (“EPD”)

EPD is a comminution technique that uses high-voltage pulses to sunder a rock into its mineral constituents.  An electric pulse travels through the rock along planes of weakness (e.g. grain boundaries) and creates extensional forces within the rock.  ODM owns and operates a Spark-2 electric-pulse disaggregator.

Some key features and advantages of EPD at ODM include:

  • ODM has strived to effectively eliminate carry-over between samples:

    • The disaggregation chamber comprises stainless steel and is completely accessible permitting it to be thoroughly rinsed and cleaned before and after every sample.

    • The EPD process occurs in water and does not generate airborne dust (a potential contaminant).

    • The disaggregation chamber is lined with a new plastic sample bag for every sample.  This ODM-exclusive development greatly reduces the risk of inter-sample contamination because both the sample material and the host water are contained within the sample bag giving a high-degree of confidence in the recovered minerals.

  • The EPD process liberates a higher proportion of undamaged, monomineralic grains compared to mechanical crushing.

  • Typically, 0.5 to 2 kg of sample is usually sufficient for most mineral separate requirements.

  • The Spark-2 has a large (25 cm/10 inch diameter) disaggregation chamber that is able to accommodate samples up to 5 kg.

  • Coarse mineral grains are not destroyed during EPD.

  • Click here to download a brief description of an internal study.

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