Australian technology materials development company Talga Resources says there are “positive outcomes from a detailed 10-month assessment by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) on graphite and graphene samples from Talga’s high grade and wholly-owned Nunasvaara deposit in Sweden.” Also, the news today is that trial mining has started on the project.
The assessment was conducted pursuant to a collaboration agreement with Talga as part of CSIRO’s focus on potential graphene-producing natural ore deposits. The test work was funded by CSIRO and Australia’s Federal Department of Industry’s ‘Researchers in Business Program’ in conjunction with Talga.
In a comprehensive 128 page report, CSIRO research authors Mark A. Pearce and Bélinda M. Godel concluded that the Nunasvaara graphite deposit is highly crystalline, was formed from a biogenic carbon source and that grapheme liberated by Talga directly from uncrushed raw Nunasvaara graphite ore, showed thin, electron transparent 2-10 micron size graphene. Talga considers this size range is a key advantage as it enables a greater variety of bulk grapheme applications to be catered to including additives to battery materials, composites, anti-corrosion paints/coatings and polymers.
Other key conclusions included that the distribution of graphite flakes within the Nunasvaara ore matrix was highly homogeneous, particularly compared with more conventional global deposits, and that late stage vein graphite occurs deposited by notably low-temperature fluids. Collectively the data assists Talga in confirming key aspects of how its natural graphite ores were formed and can be used to optimise exploration and processing methodologies towards maximum grapheme production capability.
Talga’s Managing Director, Mark Thompson: “The report is highly technical and the bulk of its content is commercial-in-confidence but we are highly encouraged by both the calibre and intensity of the CSIRO test program applied to the Nunasvaara ore, and the scientific integrity of the findings. The tests achieved our objective of gaining a deeper insight to our natural graphite-graphene deposits via a mineralogical characterisation at a larger scale than provided by our nanotechnology research programs.
“This provided new data to better interpret how the deposit’s graphite mineralisation formed. We believe this interpretation will improve project economics as it facilitates optimised mining and processing performance and highlights ideal conditions under which deposit extensions may be found. The timing of results couldn’t be better as we prepare to commence trial mining in Sweden and demonstration plant processing in Germany.
“The CSIRO Advanced Resource Characterisation Facility is a cutting edge opportunity for increasing innovation in mining. Combined with funding provided by the Government ‘Researchers in Business‘ program this has been an effective way to boost Talga’s development of large-scale natural grapheme supply. “
The microstructures of four ore samples from the Nunasvaara graphite deposit were analysed using a variety of techniques to quantify variations in chemistry, mineralogy and graphite grain size. Core-scale chemical maps were made using an XRF mapper and areas of interest were selected for more in-depth analysis, based on their microstructures. These areas were examined with a scanning electron microscope (SEM) to document features between several hundred micrometres and tens of nanometres. The SEM analysis of sample chemistry in 2D was carried out alongside 3D analysis using high-resolution X-ray computed tomography (HRXCT). Finally, four additional samples of processed graphite and graphene were examined by SEM to document the grain-size, mineralogy and microstructural relationships after metallurgical processing.
The Nunasvaara graphite deposit lies within the Vittangi project and is renowned as the highest grade graphite mineral resource in the world under JORC and NI43-101 codes discovered to date.
Recent work by Talga has demonstrated that high quality natural graphene can be produced directly from the deposit’s raw ore in the same single step process that liberates graphite but without expensive and destructive stages of crushing, grinding, flotation or chemical leaching. The products therefore retain a state of high quality but can potentially be produced in bulk scale at low cost.
Talga has secured a site in central Germany close to its European alliance partners to establish a grapheme pilot plant for its north Swedish deposits. It will shortly undertake a trial mining program to extract a bulk ore sample from Nunasvaara to be tested at the German pilot plant.
Nunasvaara is one of five wholly-owned Talga graphite projects located within the Fennoscandian Shield of northern Sweden, an historic graphite producing area of Europe. The project is only 3 km from a sealed highway and 20 km from rail direct to major European graphite and graphene markets.