Cold War politics and U.S. trade sanctions have ensured that Cuba remains a land of mystery to most of us. The country’s mineral prospectivity has also largely been hidden away for many decades.
But now a handful of junior mining explorers are venturing to the island’s shores looking to make their fortunes. Backed by a supportive Cuban government, these Canadian and Australian juniors believe they are on the trail of some significant precious metal discoveries and developments.
ASX-listed Antilles Gold Limited (ASX: AAU) (OTCQB: ANTMF) recently highlighted the exploration potential of the island nation when it revealed it had drilled a number of high-grade intercepts at the La Demajagua gold-silver deposit in Cuba.
The company is undertaking a 15,000m drilling programme at La Demajagua, which is scheduled for completion in mid-August 2021 and with assay results being received until the end of September 2021.
On 17 August, Antilles reported it has received high-grade gold and silver results from the latest 35 cored drill holes. Highlights from the assays included 5.0m @ 5.37 g/t Au & 79.38 g/t Ag from 6.5m; 6.0m @ 13.25 g/t Au & 39.88 g/t Ag from 177.0m; and 15.0m @ 4.76 g/t Au & 85.95 g/t Ag from 102.0m.
Executive Chairman Brian Johnson, said the results reflected high-grade mineralization evidenced in 50,000m of drilling of the La Demajagua ore body previously undertaken by Canadian mining companies, with samples being analysed at Activation Laboratories in Toronto.
The current drilling programme and a 10,000m in-fill programme scheduled for early 2022, are aimed at establishing JORC Resources and finalising planning for the proposed open pit mine at La Demajagua.
Additional holes will be drilled in September 2021 for geotechnical and hydrogeology investigations which will form part of the Definitive Feasibility Study for a proposed open pit mine.
“We are pleased to receive the third set of results from the initial 15,000m drilling programme that is nearing completion, and continue to be impressed with the high-grade of ore that will be available for the relatively low-cost open pit mining operation planned at La Demajagua,” Mr Johnson said.
said he noted that, based on historic drilling results and previous metallurgical test work undertake by joint venture company Minera La Victoria SA (MLV), in which Antilles Gold has a 49% shareholding, planning is underway for the open pit operation at La Demajagua which would mine approximately 800,000 tpa of ore for six years to produce 60,000 tpa of high-grade concentrate.
He also said that capital cost estimates for the proposed mine, based on a preliminary pit design, quotations for mining equipment, and turnkey offers for the design and construction of the milling and flotation circuits, and a 10Mw power station, are in the order of US$60 million including financing costs during construction, but excluding contingency.
He noted that operating costs in Cuba are low and a Preliminary Economic Assessment (PEA) for the mine completed by MLV indicated a financially robust project.
He said economics should be further improved by the addition a planned 10-year underground operation. However, exploration for that planned underground operation will most likely not take place until three years after the open pit mine is commissioned, which is targeted for late 2023.
Second Cuban mine in the offing
Antilles Gold’s faith in Cuba’s potential was highlighted in March when the company confirmed it had signed an agreement with Cuban Government owned mining company GeoMinera SA over the Golden Hills sulphide deposit, located 560km east of Havana and 80km southeast of the city of Camaguey.
The deal with GeoMinera SA is expected to lead to the submission of a proposal to conduct a limited exploration programme and the preparation of a PEA.
The proposal, once approved by GeoMinera, will be incorporated in a formal International Economic Association (IEA) between the two parties, which is the equivalent of an Exploration License.
The IEA will commit Antilles Gold, at its cost, to preparing the PEA, and if as expected the results are attractive, Antilles Gold and GeoMinera will then negotiate the terms of a joint venture for the development of an open pit mine to produce gold concentrate.
Mr Johnson said the structure of the 49:51 joint venture should be similar to that formalized in August 2020 by Antilles Gold and GeoMinera for the development of the La Demajagua gold/silver mine on the Isle of the Youth in southwest Cuba.
Mr Johnson said the project is likely to be a viable producer of large volumes of refractory concentrate that could add to the planned production from the La Demajagua mine.
OTC listing chasing U.S. investment
Earlier this year Antilles announced that it had received listing approval and has commenced trading of its common shares in the U.S. via the OTCQB Venture Market (OTCQB).
The company believes the OTCQB listing will help it establish a significant shareholder base in the U.S. and provide the company with additional liquidity.
“Given its proximity to the U.S., and President Biden’s announced plans to ultimately normalize relations between the two countries, I believe a particular segment of the U.S. investing market will be most interested in the emerging mining sector in mineral rich Cuba, and in Antilles Gold’s potential growth through its existing and future gold projects,” Mr Johnson said.
Successful nickel-producing history
Cuba is not all about precious metals. The country has a successful history in the base metals space, particularly in nickel production.
Canada’s Sherritt International Corporation (TSX: S) is part of the Moa Joint Venture which produces class I nickel and high-grade cobalt products in Cuba.
The Moa JV is 50% owned by each of Sherritt and General Nickel Company S.A. of Cuba, and has a proud history stretching back more than 25 years.
Moa uses an open-pit mining process to mine lateritic ore, which is processed using high-pressure acid leaching on-site into mixed sulphides containing nickel and cobalt. The mixed sulphides are then transported to Fort Saskatchewan, Alberta, where they are refined into high-quality finished nickel and cobalt as well as a by-product ammonium sulphate fertiliser. Mixed sulphides production at the Moa JV in Q1 2021 was 3,931 tonnes, down 2.0% from 4,014 tonnes produced in Q1 2020. The decline was primarily due to the negative impact of heavy rainfall on mining operations and variations in ore quality.
