공시 • Jul 07
Nagambie Resources Announces Confirmation of Costerfield-Mine-Style, Antimony-Gold Mineralisation at Nagambie Mine
Nagambie Resources announced that the first four diamond holes drilled in the 2022 program have all intersected significant stibnite veining striking N to NNW. Historically, all mineralisation was thought to run E-W and all drilling was N-S to hit the expected mineralisation at right angles. It is now evident that post this E-W mineralisation, secondary Costerfield-Mine-style stibnite mineralisation has been emplaced in N to NNW cross faults. The first stibnite intersection, in NAD007. Subsequently, holes NAD008, NAD009 and NAD010 have all intersected massive stibnite veining, including pieces of solid, near-100% stibnite. Further, NAD010 also intersected significant laminated quartz veining with the massive stibnite. Such laminated quartz regularly occurs besides the stibnite mineralisation at the Costerfield Mine, where it can contain very high grades of free gold. Half-core sawn samples from the first two holes, NAD007 and NAD008, have been submitted to the laboratory and first assays are expected in late July or early August 2022. The current drilling was initially targeting only the C1 vein (where "C" stands for "Costerfield-Mine-style, antimony-gold veining") which was intersected by the NRP002 hole in 2006 but which was unsuccessfully followed up at that time. The C1 vein strikes N and is close to vertical in dip. The C2 vein, previously unknown, appears to coalesce with the C1 vein but, where the vein is separate, appears to strike NNW and dip steeply W. The stibnite veining currently extends in depth between around 90m and 140m vertically below surface but is open in both directions (the upward limit is expected to be the depth of oxidation which is around 60m below surface). The stibnite veining also currently extends over approximately 60m in strike but is open in both directions. The estimated true widths (ETWs) in this announcement are "visual" adjusted for oriented strike and dip from the down hole intercepts of massive stibnite veining only. The "cut-off" ETWs could be significantly wider as it is difficult to visually estimate low Sb grades down to a cut-off grade of (say) 1.0% Sb and will only be calculable after the receipt of the detailed laboratory assays. The "visual" ETWs shown in Figures 1 and 2 of 14cm, 44cm, 25cm and 95cm nevertheless compare favourably with the "cut-off" ETWs reported over time for the Costerfield Mine which typically has mined very narrow reefs, down to around 20cm ETW. The NRP002 intersection was first reported in full to the ASX on 30 October 2006 and was re-reported on 3 March 2022 by Nagambie Resources. Some of the massive stibnite veining intersected in NRP002 is shown in Photo 6. The assays for all of the individual intercepts making up the full intercept length of 27.1m from 109m to 136.1m down hole (the "cut-off" ETW for NRP002, due to the approximate N-S drilling angle, could prove to be a small percentage of 27.1m, possibly circa 10% or 270cm). The high Sb% assays (representative of massive stibnite veining) are highlighted in blue and the Au g/t assays are highlighted in relative orange. For the high Sb% assays, the Au g/t values correlate quite well. Nagambie Resources considers that, in these cases, microscopic gold is probably present within the stibnite (Sb2S3) as aurostibnite (AuSb2), giving rise to the correlation. Aurostibnite is known to occur at Costerfield within the stibnite. While stibnite has a bulk density of 4.56, aurostibnite has a bulk density of 9.98. Where better Au g/t assays are not related to high Sb% assays, Nagambie Resources considers that the gold relates to laminated quartz veins. Antimony features highly on the critical minerals lists of many countries including Australia, the United States of America, Canada, Japan and the European Union. Australia's mine production of antimony currently comes from a single mine, the Costerfield Mine 45km west of the Nagambie Mine. Costerfield produces an antimony-gold flotation concentrate which is shipped overseas where final antimony products (antimony metal or antimony trioxide powder) are produced. Cumulative production of antimony from 2013 to 2020 is shown in Graph 1. China, Russia and Tajikistan dominate production. Antimony alloys with lead and tin which results in improved properties for solders, ammunition (bullets, artillery shells, rockets, missiles), bearings and batteries. Antimony is a prominent additive for halogen-containing flame retardants. Adequate supplies of antimony are critical to the world's energy transition and to the high-tech industry, especially the semi-conductor and defence sectors. Antimony is a critical element in the manufacture of lithium-ion batteries and to the next generation of liquid metal batteries that are predicted to lead to scalable energy storage for large wind and solar renewable power projects. Various factors, including declining mine production in China, have led to a significant increase in the antimony price in the last 1-2 years.