Alkane Resources’ Costerfield gold-antimony mine in Victoria reported an Ore Reserve of 15 thousand tonnes of contained antimony as at 30 June 2026, up 40.2 per cent on the previous year, net of 2 thousand tonnes of depletion. Measured and Indicated Resources contain 42 thousand tonnes and Inferred Resources 12.9 thousand tonnes. The FY26 Resources and Reserves Statement, dated 11 September 2026, extends the demonstrated mine life from five to six years, with production scheduled to 2032, and tests the reserve at US$22,000 a tonne for antimony. Costerfield produced 1,298 tonnes of antimony in FY26, in a gold-antimony concentrate that Alkane says is sold under existing offtake arrangements, without naming the buyers. The operation’s most recent disclosure of destinations was in its 2023 modern slavery statement, which lists two smelters in China and one in Oman; the Omani plant has been idle since the start of 2024.
Larvotto Resources restarted production at its Hillgrove mine in New South Wales on 31 August 2026, and produced first concentrate after its flotation circuit and filter presses were commissioned on 21 September. The company’s written guidance, in its March 2026 quarterly report and its first-concentrate announcement, is approximately 4,900 tonnes of antimony a year over an initial eight-year mine life. On 10 September 2026, the day the mine officially opened, managing director Ron Heeks told ABC News around 5,000 tonnes.
Hillgrove’s flotation circuit produces a 60 per cent antimony concentrate, sold under a binding seven-year exclusive offtake with the trader Wogen Resources. Its gold concentrate, about 15,000 dry metric tonnes a year, goes to Glencore International AG under a separate seven-year agreement. Where the antimony concentrate goes is Wogen’s decision rather than Larvotto’s. Heeks said in November 2025 that Wogen would sell to smelters in Asia outside China or in Europe, naming India as the largest smelting market outside China. Wogen stated in May that it expected the first shipment in September 2026; none has been announced as of today.
Against world mine production of 110,000 tonnes estimated for 2025 in the US Geological Survey’s Mineral Commodity Summaries 2026, 4,900 tonnes a year is 4.5 per cent. Larvotto has described Hillgrove’s output as 7 per cent of global mine supply, of global requirements and of demand; worked backwards, 7 per cent implies a market of about 70,000 tonnes.
Larvotto’s September quarter report is due by 31 October 2026 and should carry the first concentrate tonnage, covering about 10 days of flotation. The December quarter will be the first full quarter of production.
Sources
Alkane Resources, Group Resources & Reserves Statement FY26 (10 September 2026): Costerfield Ore Reserve 15 kt Sb; Measured and Indicated 42 kt; Inferred 12.9 kt; underlying Costerfield Resources and Reserves Statement FY26 dated 11 September 2026.
Australian Mining, “Alkane boosts gold reserves at two key mines”: antimony reserve up 40.2 per cent after 2 kt depletion in FY26.
Discovery Alert, “ALK Alkane Costerfield Ore Reserves Grow to 170koz”: mine life extended from five to six years, to October 2032; reserves tested at US$22,000/t Sb.
Alkane Resources, Appendix 4E and Full Year Statutory Accounts (21 August 2026): Costerfield produced 1,298 t antimony in FY26 (full-year basis); antimony recovered into a gold-antimony concentrate and sold under existing offtake arrangements.
Mandalay Resources Costerfield Operations, 2023 Modern Slavery Statement: gold-antimony flotation concentrate shipped from the port of Melbourne to one of two smelters in China or a smelter in Oman.
The Metalnomist, “SPMP Oman Antimony Smelter Sale Could Reshape Non-China Supply Options” (August 2026): Sohar smelter idled since the start of 2024.
Discovery Alert, “Hillgrove Antimony-Gold: What the Early Numbers Actually Mean”: first production 31 August 2026.
Kalkine Media, “Larvotto Resources Achieves First Antimony and Gold Concentrate Production at Hillgrove Mine”: flotation and filter presses commissioned as of 21 September 2026; Glencore International AG seven-year gold concentrate offtake, about 15,000 dmt a year.
Larvotto Resources, March 2026 Quarterly Report: approximately 4,900 tonnes a year; about 7 per cent of global mine supply.
Mining Technology, “Larvotto begins gold and antimony concentrate output at Hillgrove”: first-concentrate announcement; approximately 4,900 tpa; initial eight-year term; 60 per cent antimony product.
ABC News, “Antimony price spike leads to new life for disused mine near Armidale” (10 September 2026): official opening that day; Ron Heeks, around 5,000 tonnes a year.
Bulls N’ Bears, “Larvotto Resources rolls out first concentrate from NSW antimony-gold mine”: binding seven-year Wogen offtake, exclusive global sales rights.
The Northern Miner, “Larvotto greets antimony demand crunch as output nears” (November 2025): Heeks on Wogen selling to smelters in Asia outside China or in Europe; India the biggest smelting market outside China.
Wogen Resources, “Larvotto Resources Limited nears first production of antimony concentrate” (published 19 May 2026, updated 1 July 2026): first shipment expected September 2026.
Larvotto Resources, ASX announcements: no shipment announced; latest filings as of 27 September 2026 are performance-rights notices of 23 September, after the first-concentrate release of 21 September.
US Geological Survey, Mineral Commodity Summaries 2026: Antimony: world mine production 110,000 t, 2025 estimate.
Larvotto Resources, homepage: 7 per cent of global antimony requirements.
The Northern Miner, “Larvotto joins antimony ranks as Hillgrove revives” (August 2026): about 7 per cent of global antimony demand, according to Larvotto.
