Announcement • Jan 30
Lepidico Limited Announces Update on its Mineral Resource Development Work at its 80% Owned Karibib Project in Namibia
Lepidico Limited announced an update on its Mineral Resource development work at its 80% owned Karibib Project ("KP") in Namibia, which ledto the upgrade of a further 1.58 Mt @ 0.54% Li2O into Indicated Resources, comprising 1.31 Mt @ 0.46% Li2O at Helikon 4 and 0.27 Mt @ 0.86 % Li2O from the Rubicon stockpiles. Over the course of 2022 Lepidico completed a series of work programs at the Helikon 4 pegmatite and over the surface stockpiles at the historical Rubicon mine to enable the reclassification of Inferred Resources as Indicated Resources, which then allows estimation of Ore Reserves for inclusion in mine planning. These workstreams are well advanced and on track for reporting on this quarter. Lepidico engaged Cube Consulting Pty Ltd. ("Cube") to update the Mineral Resource estimate ("MRE") based on this work. The estimation work was reported in accordance with the requirements of the JORC Code (2012) and was completed between October 2022 and December 2022. The Mineral Resource Estimate Report prepared by Cube is dated 31 December 2022 and is an update to previous MRE work conducted in 2018 by the MSA Group of South Africa (Helikon 4) and in 2021 by Resource Evaluation Services (Rubicon stockpiles). HELIKON 4: Location, Geology and Mineralisation: Helikon 4 is part of the Helikon group of LCT-type lithium pegmatites, located in the northern portion of ML 204, that have been intruded into marbles and calc-silicate schists along two roughly east- west trending lines approximately 1 km apart. The Helikon 1 pegmatite occurs on the southern line. The Helikon 2 to Helikon 5 deposits occur on the northern line as part of a semi-continuous pegmatite over a 1,700 m strike length. Lithium mineralisation consists mainly of micas (lepidolite and lithium- bearing muscovite), with small amounts of amblygonite and petalite. The Helikon 4 deposit covers some 400 m of this strike. There is also a smaller undifferentiated pegmatite (referred to as the hangingwall or HW Pegmatite) immediately to the south of the main pegmatite body. Geological interpretation at Helikon 4 differentiated the pegmatite into a central but often poorly- developed, thin quartz core component, generally surrounded by a lepidolite-rich zone. In distinction to prior interpretation at the larger Rubicon and Helikon 1 deposits, domaining of the pegmatite was simplified into three zones, being, quartz core, lepidolite zone (including massive lepidolite and disseminated lepidolite) and undifferentiated pegmatite (which includes lower grade lithian muscovite). Drilling: Resource interpretation is based on a total of 66 drill holes for 6,962 m of combined reverse circulation ("RC") and diamond core drilling. Work completed by Lepidico consists of 37 RC holes (including 6 with NQ diamond tails) for 3,096 m of infill and extensional drilling. Drill hole spacing is irregular due to constraints caused by topography and the presence of ahistorical pit. Section lines are generally spaced 15 m to 30 m apart, with most holes drilled from the southern hangingwall side and intersect the steep to moderately dipping pegmatite at a reasonable angle. For the 2017 and 2018 drilling downhole surveys were taken every 50 m for the deeper holes.The RC holes and diamond tails from 2022 were not surveyed. Sampling: Sampling of RC holes was at 1 m intervals through the pegmatite and into the immediate wall rock through a 75:25 riffle splitter. Diamond core samples were half-core, nominally at 1 m intervals and modified according to geological contacts through the pegmatite and the immediate wall rock. Samples were crushed (>70% passing -6 mm) and milled (85% passing 75 m) at the ALS Chemex sample preparation facility in Okahandja. An aliquot of the sample was submitted to ALS Chemex Johannesburg for analysis by method ME-MS61, a four-acid digest and ICP-MS finish for a suite of 48 elements (including Li, Cs, Rb, Ta, K). Bulk Density: Bulk density was determined by the Archimedes method from 107 readings taken from the six diamond tails from the 2022 program and recorded to four decimal places. These were compared against 393 readings from previous drilling (recorded to only one decimal place) to inform a strategy for a single density assignment for pegmatite of 2.65 g/cm . Metallurgy: Lepidico has performed a range of testwork designed to prove its proprietary technology (L-Max and LOH-Max) for the commercial extraction of lithium and other cations from micas (and amblygonite), culminating in the release of a Definitive Feasibility Study in 2020. This level of detail provides sufficient confidence that the Helikon 4 deposit and the Rubicon stockpiles satisfy therequirement of reasonable prospects for eventual economic extraction. Estimation Methodology: One metre downhole composites were extracted from a coded database for the main mineralised domains as inputs to the geostatistical and variographic assessment. The estimation wasundertaken using Ordinary Kriging of the downhole composited drilling data into a three-dimensional block model, with an estimation block size of 10 mE × 5 mN × 5 mRL. Estimation was undertaken for a range of elements, including lithium, caesium, potassium, rubidium and tantalum. The estimation was modified in those areas where significant petalite mineralisation was recognised from logging. Petalite contains abundant lithium, but that lithium is not extractable by the specific methods that Lepidico is looking to employ for this project. Based on categorising the logging data,an indicator variable for petalite was coded into the database, and Ordinary Kriging of the indicator undertaken in a separate block model. A threshold figure for the petalite indicator of 0.45 was used as a proxy for the approximately 6% of the logging data where petalite was a major or secondarymineral. Element grades in the main block model were reset to zero in those areas above the petalite indicator threshold, which represented around 6% of the pegmatite by volume. This method effectively minimised the potential for bias in estimating `extractable lithium.' The classified mineral resources for Helikon 4 are shown in Table 4, reported above a lithium lower grade cut off of 0.15% Li2O. Compared to the previous MRE (1.51 Mt @0.38% Li2O, all Inferred), the updated MRE represents a 30% increase in contained Li2O, with 82% classified in the Indicated category.