Antilles Gold Limited (“Antilles Gold” or the “Company”) (ASX: AAU, OTCQB: ANTMF) advises that subsequent to the ASX announcement on 13 September 2024 which reported potential antimony production from the proposed La Demajagua gold-silver- antimony mine in Cuba, additional metallurgical test work data has been received from Chinese engineers, BGRIMM Technology Group (http://english.bgrimm.com/).
The Technical Consultant for the project, Vancouver based JJ Metallurgical Services Inc, has revised production targets for the two concentrate products expected to be produced by the La Demajagua mine. (refer attached Memorandum and JORC Edition 2012 Table 1)
The production targets have been based on the Pitshell 49 resource modelling incorporated in the initial Scoping Study for the project reported to ASX on 30 March 2023, and the antimony content derived from the metallurgical samples.
Based on a mill throughput of 815,000 tonnes per annum (‘tpa’), and reverse flotation of the bulk flotation concentrate at a mass pull of 10%, it is expected that ~50,000tpa of a gold-arsenopyrite concentrate will be produced with a grade of ~31.9g/t Au and ~4.9% Sb (antimony), together with ~5,560tpa of a gold-silver-antimony concentrate grading ~49.1g/t Au, ~2,000g/t Ag, and ~46.2%Sb.The gold-arsenopyrite concentrate will be subjected to alkaline leaching to selectively dissolve antimony. After solid/liquid separation, the dissolved antimony will be precipitated to produce ~3,980tpa of an antimony precipitate with an estimated ~48% Sb content.The antimony precipitate will be blended with the gold-silver-antimony concentrate to produce a final concentrate product of ~9,540tpa grading ~29.9g/t Au (~9,170oz Au per year), ~1,200g/t Ag (~368,000oz Ag per year), and ~47% Sb (~4,480t Sb per year).The gold-arsenopyrite concentrate produced after alkaline leach is expected to be ~45,670 tpa grading ~34.6g/t Au (~50,800oz Au per year).The 50% owned joint venture which is developing the project plans to oxidise the refractory gold-arsenopyrite concentrate followed by cyanide leaching to produce a higher value gold doré.BGRIMM has recently completed 9 months of metallurgical test work on the La Demajagua concentrate which demonstrated the technical viability of constructing a two-stage fluidised-bed roaster and cyanide leach circuit, and established a ~92% gold recovery from the gold-arsenopyrite concentrate.The methodology and cost of stabilising arsenic which is generated during roasting, also needs to be established through test work currently being undertaken by specialists in Canada.Based on the production targets advised by consultants, and at current prices for gold (US$2,600/oz), silver (US$30/oz), and antimony (US$25,000/t), and payables for contained metal in the gold-silver-antimony concentrate offered by potential buyers (55%, 65%, and 57% respectively), revenue for this concentrate could be in the order of US$84 million per year for the 9 year mine life for the first stage, open pit operation.The potential sales value of contained antimony in the gold-silver-antimony concentrate could now be over US$40 million per year more than assessed in March 2023, demonstrating its growing importance to the La Demajagua project.The income for this antimony-rich concentrate will be in addition to that received for ~47,000oz Au per year forecast to be contained in the gold doré.A new Scoping Study for the expanded project incorporating the processing facility and the production of a gold doré and an antimony-rich concentrate will be completed after the estimated construction and operating costs have been received from BGRIMM, and is expected to demonstrate robust returns at conservative metal prices.
COMMENT:
Antilles Chairman, Brian Johnson said: “with improved supply-demand dynamics for antimony and a strengthening price environment, we are now rapidly advancing project development studies with the assistance of BGRIMM Technology Group and our Technical Consultants. The initial production targets defined for La Demajagua is a good starting point and we look forward to delivering the Scoping Study for an expanded operation. We are also engaging with a wider cohort of potential antimony buyers given the stronger demand and price environment for the strategic metal.”
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