Antilles Gold Limited (ASX:AAU) has announced the successful completion of metallurgical test work by BGRIMM Technology for the La Demajagua gold-silver-antimony mine in Cuba. The test work confirmed the potential for significant antimony production from the gold-arsenopyrite concentrate to be produced by the open pit mine. BGRIMM Technology, a leading Chinese engineering group, conducted the test work over a 9-month period to demonstrate the technical viability and design parameters for the processing facility, which will include a two-stage fluidised-bed roaster, an acid plant, and CIL circuit to produce a gold doré, along with a separate leach circuit to recover antimony from the gold-arsenopyrite concentrate before roasting.
One multiple-day flotation pilot plant campaign was completed in late 2022 by SGS in Ontario, Canada, using a composite sample from the La Demajagua project. The gold-arsenopyrite concentrate sample was then sent to BGRIMM Technology in Beijing, China, for roasting test work. BGRIMM's roasting test work program covered a series of scope of work, including alkaline sulphide leach, two-stage roasting, acid leach, and carbonate leach, resulting in estimated annual antimony production of ~4,786tpa. The estimated loss of gold during the process was about 0.94%, leading to a net gold recovery of 91.4%. The estimated loss of silver was about 1.10%, resulting in a net silver recovery of 90.3%.
The successful completion of the metallurgical test work by BGRIMM Technology marks a significant milestone for Antilles Gold's La Demajagua project in Cuba. The potential for significant antimony production, with estimated annual production of ~4,786tpa, is expected to enhance the project's profitability and NPV. The company's joint venture mining company, Minera La Victoria, aims to have the project development-ready in Q4 2025. Antilles Gold's corporate strategy includes the development of two mineral deposits in Cuba to produce gold, silver, antimony, and copper, as well as the exploration of potentially large porphyry copper deposits through its joint venture with the Cuban Government's mining company, GeoMinera SA. The company also plans to invest part of the expected surplus cash flow from the Nueva Sabana mine to fund exploration of major copper targets, demonstrating a commitment to long-term growth and sustainability.