Recent Exploration and Development
2012 – 2013
Following the acquisition of the Wolfsberg project, GSM undertook exploration drilling in 2012 on the southern limb of the anticline which confirmed the structural interpretation and presence of lithium bearing pegmatite veins. Mining was undertaken in 2013 to validate the mining license and to collect 500 tonne bulk samples from the two ore types for metallurgical testing. The Minerex drilling data was utilised to develop a three dimensional resource model for use in mine planning.
Historic Exploration and Development
- 16,727m of drilling / 1,389m of decline, drives and crosscuts
- Deposit is split into two zones:
|Zone 1: the northern limb of an anticline was drilled by Minerex down dip to a maximum depth of 450m and mapped over a distance of 1500m. Lithium bearing pegmatite veins up to 5.5m wide intersected and ore body remains open along strike to the west and down dip.|
|Zone 2: exploration target, demonstrated to be the southern limb of an anticline of which the northern limb (Zone 1), was the focus of all exploration by Minerex.|
- The resource was declared by previous owners to German and Austrian reporting standards and by GSM to JORC Code (2004):
|Type||Million Tonnes||Grade Li2O
- *JORC 2004 Measured resource at a cut-off grade of 0.75% Li2O derived from a global measured resource of 4.7Mt @ 1.2% Li2O
- JORC 2012 Resource has reclassified Measured to Inferred and Indicated and Inferred to Exploration Targets
A JORC Code (2004) compliant resource was declared in 2012. As part of the Competent Person Report, the Resource has been restated due to the lack of primary data on the Minerex drilling methods and core recoveries, procedures followed when sampling the core and QA/QC procedures during core core sampling and chemical analysis. Considerable primary data has now been located in Ministry archives in Austria and this will be reviewed and together with a verification programme of Minerex data under a comprehensive QA/QC protocol then the Board believes it will be able to re-classify its Resource to the Measured and Indicated category compliant with the JORC Code (2012)
Drilling will be undertaken to establish a Resource in Zone 2 where boulder mapping and scout drilling have proved the presence of lithium bearing pegmatites.
Pre – 2012
Minerex completed exploration work that comprised initial surface geology mapping along with 9,940m³of surface trenches and a diamond drilling programme totalling 12,012m collared from surface. In 1985 an underground exploration programme was undertaken including development of a decline from the surface from the northern side of Brandrucken Mountain through the amphibole schist to provide access to the pegmatite veins. Crosscutting drifts were driven along strike of selected veins to provide access for mapping and sampling and an additional decline was driven to access the veins in the mica schist. In all 1,389m ofunderground development was mined. A diamond drilling campaign of 4,715m was undertaken from underground to effectively infill the surface drilling to about 50m intervals in the eastern part of Zone 1.
Section through deposit
- Mineral processing studies were undertaken for Minerex by the North Carolina State University.As a result of the testwork, using flotation and magnetic separation, spodumene concentrate with Li2O grades greater than 6% could be produced with spodumene recoveries of over 85%. Furthermore, ceramic grade feldspar and glass grade quartz were also revoverable. Mica concentrates were also considered a possible by-product. A pilot plant was set up which demonstrated that of all the mined and processed ore 74% was a saleable product
- Since this work in the mid 1980’s there have been numerous advances in metallurgical technologies. and the group intends to complete testwork on the bulk samples extracted during 2013. The testwork will include dense media separation, flotation and magnetic separation to obtain high recovery/high grade of spodumene concentrate and marketable quality of feldspar, quartz and mica with samples generated for introduction to potential offtakers. In recent years optical sorting has become increasingly established and its potential application to the Wolfsberg project for rejection of waste will be evaluated..