Dakota Minerals’ latest results from the Sepeda lithium project in Portugal, including 74m @ 1.54% Li2O, represents the next positive step in delivering its European strategy. MD David Frances said the discovery of a significant hard-rock lithium deposit on the doorstep of Europe’s rapidly evolving battery market was testament to the foresight and work of the team. He said Dakota would now fast-track development of Sepeda and work to transition from successful explorer to downstream producer.
Highlights
- Latest results confirm Sepeda as a major new European hard-rock lithium discovery
- Remainder of phase one drilling results confirm presence of very thick, lithium-bearing pegmatites from surface and widening at depth
- Results include 74 m @ 1.54% Li2O and 27 m @ 1.49% Li2O -open in all directions
- Phase two drilling already under way, targeting a maiden resource by CY Q1 2017
- Metallurgical test-work under way, for production of battery and technical grade lithium carbonate/ lithium hydroxide products
Dakota Minerals Limited (“Dakota”, “DKO”, or “Company”) is pleased to finally announce the remainder of the phase one drilling results at the Sepeda Lithium Project, Portugal after significant laboratory delays. The Company is looking at alternative assaying arrangements for future drill programmes.
Spectacular drilling widths and grades, including 74 m @ 1.54% Li2O, confirm Sepeda as a major new European hard-rock lithium discovery. Significantly, the discovery is located in a global top-10 Fraser Institute ranked country, and is being serviced by established infrastructure linking it to the European battery and technical markets.
Material from Sepeda is undergoing metallurgical test-work at Dorfner-Anzaplan in Hirschau, Germany. The test-work aims to optimise processing techniques for the Sepeda petalite to produce high-value products, including lithium carbonate and lithium hydroxide, with the ability to also deliver into the technical or battery markets.
Following the highly significant results from phase one drilling at Sepeda, Dakota has accelerated its exploration programme in Portugal. Phase two drilling has already commenced, targeting a maiden resource by CY Q1 2017. Resource development drilling has commenced, ahead of schedule, at the Romano pegmatite within the Sepeda project.
Dakota Minerals CEO David Frances commented: “The latest results represent the next positive step in Dakota’s fast-tracked European lithium strategy. The discovery of a potentially highly significant hard-rock lithium deposit at Sepeda, on the doorstep of the rapidly evolving European battery market, is testament to the foresight and hard work of the Dakota team and an outstanding result for shareholders”.
Mr Frances said the rapid development and subsequent sale of the Lynas Find asset gives the Company a very strong cash position: “We can now fast-track the development of Sepeda, as we work to transition from a highly successful explorer to a downstream producer of high-value lithium products focussed on the global energy transition.”
Future Works
A maiden resource at Sepeda is now being targeted for Q1 CY-2017. Dakota has accelerated its exploration programme in Portugal. Resource development drilling has already commenced, ahead of schedule, at the Romano pegmatite within the Sepeda project. Phase two drilling will also test other currently identified pegmatites within the Sepeda area. Metallurgical test-work on a bulk, 200kg sample of Sepeda pegmatite material is under way at Dorfner-Anzaplan in Germany to determine optimal processing parameters for producing high-value downstream lithium products (lithium carbonate and lithium hydroxide). Final results from this test-work are due around April 2017.
About the Sepeda Lithium Project
Sepeda is situated on granted tenement MNPP04612, within the Barroso-Alvão district, one of three areas that form Dakota’s Lusidakota holdings in Northern Portugal, and serviced by excellent existing infrastructure. The Barroso-Alvão Pegmatite Field, in the Variscan Belt, contains rare-element aplitic LithiumCaesium-Tantalum (LCT) pegmatites with significant Li, Sn, Nb, Ta, Rb, and P enrichment. The Sepeda Project is focussed on the Carvalhais pegmatite swarm in an old mining jurisdiction known as Minas do Beça. Pegmatites were mined in the mid-20th century for tin and tantalum. The mines are situated in a NNW trending corridor with over 3,000 m of strike and 500 m in width with at least 140 separate open pits, shafts and adits, the largest of which is Romano, spanning a 300m strike and up to 52 metres wide. Mining by hand was undertaken principally from the highly weathered zones up to 30m below surface, but generally less than 15m.
The pegmatites are hosted in a variety of NW trending, generally steeply SW dipping, metasedimentary rocks including biotite schist and quartz biotite schist with minor garnet, andalusite-bearing schist and phyllite, with lesser quartzite and psammopelite. The metasedimentary sequence is intensely folded, with a strong axial planar foliation developed and open to isoclinal folds typically plunging 30 to 70 degrees to the NW (320°). The pegmatites are folded in slightly recumbent to upright folds with thicker pegmatites commonly developed in the fold nose of anticlines. Larger pegmatite bodies such as Romano appear to be more tabular.
Structural and lithological mapping, rock-chip and auger sampling were conducted in the Sepeda region of the Barroso-Alvão project area in June 2016 (1) . The main pegmatite swarm area has recently been mapped over a strike of 3,000 m and up to 1,000 m in width at its widest point. Some of the pegmatites do not outcrop and are visible only in the underground workings. Lithium mineralisation grading up to 2.8% Li2O was present in petalite and spodumene1 samples at surface and from underground workings. Phase one drilling – 18 holes for 2,090 m, has now been completed, and all samples reported.
About Petalite
X-Ray Diffraction (XRD) work on the Sepeda deposit has shown petalite to be the predominant lithium mineral with some associated spodumene and appears to have very low muscovite mica content, which is advantageous from a processing perspective. Petalite, a lithium aluminium tectosilicate, is an important ore mineral for lithium. It has a density of 2.4 g/cc, and a hardness of 6. Its colour is white, grey-white and more rarely light pink, and is a well-known occurrence at the Bikita mine, in Zimbabwe. The petalite crystals accommodate little iron, so petalite deposits generally have a low iron content. Whilst historically it has been mined for the glass-ceramic industry, petalite can also be processed to produce chemical grade lithium carbonate/hydroxide products for the rapidly-growing battery market. Petalite is amenable to similar processing techniques to spodumene(2), to produce a chemical grade lithium carbonate/hydroxide product.
Phase One Drilling Programme Details
Dakota’s phase one drilling programme in Portugal comprised 18 holes (SC001-SC018) for a total of 2,090 metres of reconnaissance reverse circulation (RC) drilling, designed to test some of the main known petalite/spodumene-bearing pegmatites. SPI SA, a drilling company based in Leon, Spain, was commissioned to carry out the programme. Holes varied in dip between -85 and -50 degrees, and varied between 48 and 231 m in depth. Drill holes were initially pegged at 80 m x 50 m spacings by differential GPS with a real time base. Drill holes were subsequently surveyed by total station and have an expected ±5cm collar accuracy. Holes were geologically logged and zones of pegmatite and proximal host rocks were sampled every metre. A total of 815 samples including QAQC were dispatched to laboratories in Spain and Ireland for assay. All batches have now been reported. Assay results indicate broad widths of mineralized pegmatite up to 74m total downhole width, including intercepts of 74 m @ 1.54% Li2O from 116 m (SC016), and 27 m @ 1.49% Li2O from 69 m (SC003). The thickest and highest grade results to date have mainly been at the Romano pegmatite, but reconnaissance drilling at the Alto da Corga pegmatite, to the south of Romano, also yielded positive mineralisation of 8 m @ 1.22% Li2O. A full list of significant intercepts is shown in Appendix 1. Many of the other currently identified pegmatites remain untested; some of these will be tested by the phase two drilling. These results, combined with those reported earlier in October, confirm Sepeda as a major new European hard-rock lithium discovery.
(1) DKO ASX announcement, 19/07/2016
(2) Sitando, O., Crouse, P.L. Processing of a Zimbabwean petalite to obtain lithium carbonate International Journal of Mineral Processing 102 · January 2011