Duyuru • Jan 12
Golden Deeps Limited Provides Update on Abenab Project
Golden Deeps Limited announced it has generated an exceptionally high-grade vanadium with zinc, lead and copper concentrate sample through gravity testwork on the Company's Abenab Project, located in Namibia's highly-prospective Otavi Mountain Land. The testwork produced an exceptionally high-grade descloizite ((Pb, Zn)2(OH)VO4) concentrate grading: 15.6% V2O5, 11.2% Zn, 38.2% Pb and 0.8% Cu. This represents an 18 times (x) upgrade of the representative drill-core composite sample, that had an assay head grade of 0.9% V2O5, 2.1% Pb and 0.7% Zn. This upgrade factor is above the targeted multiple of 15x and concentrate grades are similar to historical concentrate production grades from the Abenab Mine, which was known as the world's richest and larger known deposit of vanadate ore, producing 176kt of very high-grade 16% V2O5, 13% Zn, 42% Pb concentrate from the 1920s to the 1950s0. The gravity concentrate testwork was conducted at Nagrom Mineral Processing Laboratories in Perth and initially included grinding sighter tests that indicated an optimal grind size of 0.5mm, followed by rougher spiral gravity concentration. Losses in the spiral concentration stage led to re-constitution of the feed and a repeat of the concentrate work using entirely wet-table gravity concentration with improved separation efficiency. This process recovered a final aggregated concentrate mass of 1.44kg at 15.6% V2O5, 11.2% Zn, 38.2% Pb & 0.8% Cu. The mass was lower than initially targeted due to losses within the original spiral circuit and the resultant high-proportion of slimes generated from the rework. Further testwork on a larger bulk sample will focus on optimising higher recoveries, targeting >80%. The final concentrate sample is being held by the Company prior to approximately 1kg of the sample being despatched for down-stream hydrometallurgical testwork. The Phase 2 testwork is designed to further develop the flowsheet for hydrometallurgical processing the high-grade vanadium, lead, zinc and copper concentrate to produce high-value vanadium products, as well as recovering zinc, lead and potentially copper by-products. Earlier Phase 1 hydrometallurgical testwork demonstrated vanadium extraction rates of up to 95% and high extraction of lead, zinc and copper from a lower grade concentrate feed generated from surface stockpiles and tailings. The outcomes of both the gravity concentrate testwork and the downstream hydrometallurgical testwork will provide processing cost inputs (capital and operating) to be integrated with a new resource model for the Abenab deposit (in preparation by Shango Solutions), and an upgraded mining study (by Bara Consulting), to produce a scoping study for staged mining, gravity concentration and downstream processing of the high-grade Abenab high-grade V-Zn-Pb resource. The discovery of high-grade copper, vanadium and lead mineralisation at the Nosib Block (Nosib) Project, located 20km to the southwest of Abenab, presents the opportunity to develop an integrated mining and two-stage processing project for both the Abenab and Nosib deposits. Samples of diamond drill-core from NSBDD0083 at Nosib with other previous intersections (NSBDD0024) and material from a recent bulk sample excavated from the top of the Nosib supergene mineralisation2 were aggregated to produce bulk samples for the gravity concentration testwork based on the flow-sheet developed for the Abenab resource material. The samples were aggregated into two bulk samples as follows: Drill core sample of ~140kg grading 1% V (1.8% V2O5), 4.1% Cu, 7% Pb, 0.1% Zn, Aggregate surface samples ~150kg 1% V, (1.8% V2O5), 4.3% Cu, 7.3% Pb, 0.1% Zn. Initial mineralogical work on the Nosib samples to determine the "ore" mineralogy of the deposit, using wet-table separates, confirmed the V, Pb, Cu (+/- Zn) phase in the samples is almost entirely in the mineral mottramite. Mottramite is a copper-lead vanadate mineral, composition: PbCu(VO4)(OH), and is part of the descloizite vanadate group. Mottramite has a high specific gravity and is likely to respond to gravity concentration similarly to the mineralisation at Abenab which is predominantly descloizite, a lead-zinc vanadate, composition: (Pb, Zn)2(OH)VO4. Wet table gravity concentration testwork has now commenced on the two, separate, bulk samples for the Nosib deposit. This work is designed to generate >5kg of concentrate, targeting a 10-15 times upgrade of vanadium, lead and copper. Following generation of concentrate from the Nosib gravity testwork, the concentrate sample will undergo hydrometallurgical leach testwork, based on the results of the Abenab program. This work will be designed to determine vanadium leach rates and recoveries to high-value vanadium products as well as copper, lead, zinc and silver by-products. The results of the initial metallurgical testwork will provide cost information for open pit optimisation work on a preliminary Mineral Resource model generated by Shango Solutions, based in South Africa. The open-pit optimisation is being carried out by Bara Consulting and is close to finalisation, which will allow finalisation of the maiden Mineral Resource estimate for the Nosib deposit. This optimisation will also provide initial mining production targets for the Scoping Study, to be integrated with the results of the Abenab testwork and mining studies to generate an integrated mining and two-stage processing development and production plan for the Abenab and Nosib deposits. The Company's key projects in the world-class Otavi Mountain Land Copper District (OMLCD) of Namibia are located on two Exclusive Prospecting Licences (EPLs) - EPL5496 and EPL3543. The OMLCD includes major historic mines such as the Tsumeb deposit that historically produced 30Mt of ore grading 4.3% Cu, 10% Pb and 3.5% Zn5 from 1905 to 1996. The Company's key projects are the Abenab high-grade vanadium-zinc-lead resource; the Nosib high-grade vanadium-copper-lead-silver discovery and the Khusib Springs high-grade copper-silver deposit, where the Company recently announced a 90m intersection of copper-silver mineralisation. At the Abenab Project the Company has a Mineral Resource estimate of an Inferred 2.80Mt @ 0.66% V2O5, 2.35% Pb, 0.94% Zn at a 0.2% V2O5 cut-off7. The resource model for the deposit is currently being updated to include information from the 2019 diamond drilling program by the Company and new processing cost information from the latest testwork, as summarised in this release. The Nosib Project is a new discovery that has produced a number of exceptional, thick and high-grade, vanadium-copper-lead-silver RC and diamond drilling intersections over the last 12 months. Mineral Resource modelling and estimation is being carried out by Shango Solutions, focussed on the supergene vanadium-copper-lead-silver zone at Nosib.