Maiden Resource at Goulamina Confirms Large Tonnage and High-Grade Lithium Deposit
v Maiden Goulamina Mineral Resource; 15.5 Mt @ 1.48 % Li2O (229,000t contained Li2O)
v Substantial high-grade, near surface component presents opportunity for enhanced early cash flow
v Excellent potential to add significant tonnages of shallow, high grade lithium mineralisation with further drilling
v Project evaluation studies in progress to define preliminary data associated with mining, processing and capital costs
v Drilling to re-commence shortly, focusing on resource extensions and upgrades to resource categories
Birimian Limited (ASX:BGS; “Birimian” and “Company” - https://www.commodity-tv.net/c/mid,1323,Interviews/?v=296968) is pleased to report the maiden JORC-compliant Mineral Resource estimate for the Goulamina deposit, at its Bougouni Lithium Project in Mali.
The estimated Mineral Resource at Goulamina is 15.5 Mt @ 1.48 % Li2O, for 229,000 tonnes of contained Li2O (Table 1). This positions the deposit as among the highest grade, hard rock lithium deposits of significant size globally today.
Commenting on the milestone, Birimian Managing Director Mr Kevin Joyce said, "We are very pleased to have 100% ownership of the highest grade lithium resource held by any ASX-listed company today.
"This maiden resource estimate is an outstanding result, especially given that first drilling occurred less than six months ago. This provides a strong platform to rapidly advance a scoping study to define the key parameters that will underpin the project Feasibility Study and first Ore Reserve estimate.
"Of note, there remains significant potential to substantially expand this maiden resource and improve the modelled grade with additional drilling, particularly at the recently discovered West Zone, where wide and high grade mineralisation remains open along strike near surface and at depth. The resource grade of 1.67% Li2O at West Zone is very encouraging, and we are eager to begin the next phase drilling program, which will commence in late November.
"Birimian is in a strong cash position with sufficient capital to fund development activities through the next round of drilling and scoping study. We expect the scoping study to be completed by year-end.”
Mineral Resource Estimate
Cube Consulting (Cube) was engaged to carry out a Mineral Resource estimate for the Goulamina deposit. CSA Global provided input to a preliminary mining study to support Cube’s work. Detailed information relating to data, quality control, and estimation methodology are documented in Appendix 1 - JORC Table 1, Sections 1 to 3.
Resources have been estimated to Indicated and Inferred confidence levels as per Table 1. Forty percent (40%) of the Mineral Resource already lies in the indicated category.
Birimian provided the principal sources of information used in this Mineral Resource estimate including drilling databases, a topographic surface, mapping information and a geological interpretation of the mineralised pegmatites. In total, 50 holes for 5,179m of drilling informed the resource model.
The mineral resources are defined by reverse circulation (RC) and diamond (DD) drilling. The majority of drilling is at 50m x 50m and 50m x 25m spacing on the Main pegmatite zone. This spacing is adequate to establish the geological and grade continuity for reporting of Mineral Resources.
The spodumene (lithium) pegmatite mineralisation at Goulamina occurs as two, well defined, broadly parallel and highly continuous dykes; the Main Zone and West Zone (Figure 1, 2 and 3). Cross cutting mineralised dykes, identified in outcrop and drilling, are less well-defined and have not been included as classified resources at this point in time.
Mineralised domains for separate pegmatite dykes were digitised in cross-section and then wireframed to generate solids. There is a very strong correlation between the mineralised portion of the pegmatite dykes and the total dyke mineralised intercept. Very little pegmatite material is not significantly elevated in lithium content; thus the mineralisation boundaries generally match the lithological boundaries of the dykes. Wireframe solids were used to populate the block model and interpolated Li2O grade by ordinary kriging methods.
The majority of the resource area of the Main Zone pegmatite was classified as Indicated Resources where specific data spacing and search criteria were met, generally within 100m from surface. Deeper mineralisation on this zone, as well as for the West Zone pegmatite, was classified as Inferred Resources due to the wider drillhole spacing and lower confidence in the interpretation of the mineralisation.
It has been assumed that the resource would be mined using open pit methods, which is supported by conceptual mining studies. The previous metallurgical studies provide a sufficient basis for the assumption regarding metallurgical amenability, and determining reasonable prospects for eventual economic extraction.
Goulamina – A Large Tonnage High Grade Lithium Deposit
The maiden resource estimate at Goulamina confirms a high-grade and bulk tonnage lithium deposit. The project is situated in close proximity to a sealed highway, grid power and abundant water, with the Selingue hydroelectric power station located some 45km to the north west (Figure 4).
Goulamina is a high grade lithium deposit with low iron contents. The grade-tonnage curve is shown in Figure 5. Significant observations include;
· The global resource is reported at 0% Li2O cut-off. At elevated cut-off grades, the tonnages of mineralisation do not vary substantially, confirming the robust grade and good continuity of the modelled mineralisation.
· Substantial tonnages of high grade (>1.5% Li2O) mineralisation have been modelled within the resource.
A significant portion of the very high grade material occurs in outcrop and near surface (see Figure 1), presenting a potential opportunity to exploit high grade ore early in the project life, allowing for rapid payback and enhanced cash flow by a suitably staged project development.
The deposit has substantial scope to expand into a large tonnage and high grade lithium project significantly exceeding early expectations. Importantly, mineralisation is open at both zones and there is significant untapped exploration potential within the 250km2 project area. Birimian remains confident that over the course of subsequent drilling campaigns, it will progressively increase the lithia inventory at Goulamina, confirming the significance of the deposit on a global scale.
Forward Plan - Drilling
Mineralisation is open along strike and to depth outside the present limits of drill coverage. The last reported drill results from West Zone (10 October 2016) returned the widest and highest grade intersections reported to date at Goulamina; including 82m @ 1.64% Li2O from 18m, and 51m @ 1.93% Li2O from 127m (with 22m @ 2.23% Li2O).
These highly significant near surface intersections are open along strike, indicating excellent potential to add substantial tonnages of high grade material by drilling in this area. Preliminary mining studies have also shown good scope to extend resources beneath the current base of the resource model at Main and West Zone.
Further drilling will investigate extensions to mineralisation during the next phase infill and step-out drilling program. Planning for this program is in progress, with an expectation that approximately 10,000m of drilling will be undertaken to expand and upgrade resource classifications, and facilitate eventual ore reserve estimation.
Scoping Study and Permitting
In parallel with drilling, Birimian is rapidly advancing a Scoping Study to define inputs into the project Feasibility Study.
Como Engineers (Como) has been engaged to determine the key processing parameters and estimate capital costs, which will be used to define subsequent phases of detailed work at the Bougouni Project. Como has significant experience in process design and engineering of spodumene concentration plants, including recently undertaking the Definitive Feasibility Study for Pilbara Minerals’ Pilgangoora Lithium Project.
Previous processing test work has confirmed the viability of the pegmatite at Goulamina to produce a high quality chemical grade lithium concentrate. Como will use this study as the basis for their preliminary evaluation. Test results show good spodumene (lithium) recoveries (84.7%) and high mass yield to produce a high quality, chemical grade (6.7%) spodumene concentrate. For reference, concentrate grades of 6% are typically demanded by global lithium carbonate producers.
Digby Wells Environmental (Digby Wells) has recently completed fieldwork for the initial social and environmental assessment for areas around the potential mine and processing site at Goulamina. This preliminary study will identify key environmental and social considerations, and will enable Digby Wells to prepare the Terms of Reference for the Environmental and Social Impact Assessment (ESIA) which will be utilised to formulate an appropriate plan for completion of necessary base line studies and submission of the formal project ESIA for mine permitting.
ASX Additional Information - Material Assumptions
The following is a summary of Material Information used to estimate the Mineral Resource as required by Listing Rule 5.8.1 and JORC 2012 Reporting Guidelines.
Mineral Tenement and Land Tenure Status
The deposit lies within the Torakoro Authorisation to Explore which is owned 100% by Timbuktu Ressources, a wholly owned Malian subsidiary of Birimian Limited. The license area is currently being upgraded to a Research Permit, which was approved for issue by interministerial commission from the Mali Ministry of Mines on 19 July 2016. The mineral property is in good standing and there is no known impediment to obtaining a license to operate.
The project area is located within the Bougouni region of the southern Mali, where broadly north-south trending belts of Birimian-aged (Paleoproterozoic) metavolcanic and metasedimentary rocks are intruded by syn-and post-orogenic granitoids.
Within the Project area, outcrop is limited and basement geology is therefore poorly understood. Regolith typically comprises a surficial transported gravel horizon (locally termed Cuirasse) overlying a thin lateritic weathering profile. Mapping indicates NE-striking metapelite and metagreywacke rocks in the north and eastern parts of the property. The southern portion of the project area is dominated by granodiorite.
All pegmatite bodies contain anomalous or significant amounts of the mineral spodumene (a lithium-bearing pyroxene), along with the other major minerals of quartz feldspar (albite and microcline); From the geological logging, there are also accessory amounts of muscovite, tourmaline, apatite, and biotite at the granite contacts. Semi-quantitative mineralogical analysis by X-ray diffraction also indicated trace amounts of zinnwaldite (a lithium-bearing mica) and chlorite.
Drilling Techniques and Hole Spacing
All holes were drilled as part of a continuous drilling campaign from May to September 2016. In total 50 holes for 5,179m of drilling were completed.
RC drilling was completed by a purpose-built rig supplied and operated by Foraco Drilling, using nominally 5.5” diameter equipment, with a face sampling downhole hammer. The rig has an outboard compressor, with specifications of 1100CFM@350PSI.
Core drilling was completed using a purpose-built rig supplied and operated by Foraco Drilling. All holes are standard HQ sized holes (core diameter 64mm). DD holes are a combination of some drilled from surface (lengths varied between 21m and 110m), and some as diamond tails on RC holes (lengths varied between 100m and 195m).
All samples collected from the RC rig for this drilling program were collected at 1m downhole intervals. Samples were split into pre-numbered calico bags at the rig using a 3-stage vibratory riffle splitter yielding a sample of between 3 to 5 kilograms. In addition to the 1m sample, duplicate samples were taken every 20m downhole. Blanks and standards were inserted into the sample string at a rate of 1:40 for Blanks, and 1:40 for Standards.
A sampling ledger documented data, including hole number, date drilled, sample id, depths from and to, sample condition, sample type, percentage sample return and all certified standards blanks and duplicates.
Drill core was sawn in half along its long axis. One half of the drill core was taken for geochemical analysis. All samples were collected at 1m intervals down the hole. 100% core recoveries were typically achieved.
Sample preparation work was conducted in the ALS Laboratory in Ouagadougou, Burkina Faso. At the laboratory, samples were weighed, dried and crushed to -2mm in a jaw crusher. A 1.0kg split of the crushed sample was subsequently pulverised in a ring mill to achieve a nominal pulp particle size of 85% passing 75μm. Sample sizes and laboratory preparation techniques are considered to be appropriate.
After pulverisation, sub-samples were sent to ALS Laboratory in Perth for assay. Analysis for lithium and a suite of other elements is undertaken by ICP-AES, after a sodium peroxide (Na2O2) fusion – ALS Method ME-ICP89. Some of the multi-element analysis uses a MS finish – ALS Method ME-MS91. This fusion technique is considered to be a “total” dissolution technique for lithium-bearing silicate minerals. Detection limits for lithium are 0.01-10%.
Interpreted sections were wireframed using Surpac to create 3D solids for each pegmatite domain within the resource area. The drillhole data was sliced on 50m spaced sections for modelling of the geology and the mineralised envelopes. Solids were constructed for 4 discreet pegmatite dykes, as well as for the near surface colluvium and lateritic material.
Mineralisation in the Main Zone and West Zone pegmatites was composited to 3m downhole intervals to reduce the variability inherent in raw samples or a smaller composite length relative to estimation resource model block dimensions.
Surpac software was used for the modelling and estimation, with SuperVisor software used to conduct geostatistical analysis. The main pegmatite domains in the block model were estimated using interpolation of grade via Ordinary Kriging (OK), which was considered to be an acceptable method given the strong geological control, the drilling density and the data distribution downhole.
A single block model was created by Cube with dimensions extended out to fully cover all of the mineralisation, plus surrounds that may be contained within pit optimisation shells. The parent block size used is 20mN x 20mE x 5mRL and sub-blocked to 1.25mN x 2.5mE x 2.5mRL.
A range of criteria were considered by Cube when addressing the suitability of the classification boundaries. These criteria include:
· Geological continuity and volume;
· Drill spacing and drill data quality;
· Modelling technique; and
· Estimation properties including search strategy, number of informing composites, average distance of composites from blocks and kriging quality parameters.
Blocks have been classified as Indicated or Inferred, mostly based on drill data spacing in combination with kriging parameters.
For the global resource estimation, no lower cutoff grade for reporting is used, as the model is essentially developed within a geological boundary, and the resource incorporates everything within the modelled pegmatite dykes.
Mining and Metallurgy
Conceptual mining studies are based on open cut mining methods using a contract mining fleet and conventional drill and blast mining methods. Limited inspection of core photography indicates that ground conditions are suitable for this mining method.
The resource has been trimmed by intersecting with a pit shell based on a Whittle optimisation at a revenue factor (USD650/t for a nominal 6% Li2O concentrate). Material falling outside of this shell is considered to not meet reasonable prospects for eventual economic extraction.
The criteria for assumptions and predictions regarding metallurgical amenability – required to determine reasonable prospects for eventual economic extraction – are based on the bulk sampling and test program undertaken in 2008 by CSA Global (UK), work that was commissioned and funded by the World Bank as part of the SYSMIN economic development program. CSA Global undertook systematic sampling of outcropping material at Goulamina to collect a representative bulk sample comprising 3,150kg of material, which was subsequently crushed and split to 750kg for detailed processing test work. This work included evaluations of screen sizing to optimize spodumene (lithium) recoveries and preliminary dense media separation tests. The results of this study indicated good spodumene recoveries (~84.7%) and a high mass yield, to produce a high quality ‘chemical grade’ spodumene concentrate (~6.7% Li2O).
For further information contact:
Mr Kevin Joyce
08 9286 3045
Swiss Resource Capital AG
Competent Persons Declaration
The information in this announcement that relates to exploration results and the Exploration Target is based on information compiled by or under the supervision of Kevin Anthony Joyce. Mr Joyce is Managing Director of Birimian Limited and a Member of the Australian Institute of Geoscientists. Mr Joyce has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and the activity he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting of Exploration Results. Mr Joyce consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
The information in this announcement that relates to Mineral Resources is based on information compiled by or under the supervision of Mr. Matt Bampton, who is a Member of The Australasian Institute of Mining and Metallurgy and a Member of the Australian Institute of Geoscientists. Mr Bampton is a full-time employee of Cube Consulting Pty Ltd and has sufficient experience which is relevant to the styles of mineralisation and types of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting of Exploration Results. Mr Bampton consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.
Previous Reported Results
There is information in this announcement relating to previous Exploration Results at the Bougouni Project. The Company confirms that it is not aware of any other new information or data that materially affects the information included in the original market announcement, and that all material assumptions and technical parameters have not materially changed. The Company confirms that the form and context in which the Competent Person’s findings are presented have not been materially modified from the original market announcement.
Forward Looking Statements
Statements regarding plans with respect to the Company’s mineral properties are forward looking statements. There can be no assurance that the Company’s plans for development of its mineral properties will proceed as expected. There can be no assurance that the Company will be able to confirm the presence of mineral deposits, that any mineralisation will prove to be economic or that a mine will successfully be developed on any of the Company’s mineral properties.