Australian-listed Antilles Gold announced that the company received interest in by-product antimony contained in its gold-rich concentrates from its La Demajagua sulphide gold-silver joint venture project in Cuba.

The La Demajagua deposit is owned in a 49:51 joint venture between Antilles Gold and Cuba government GeoMinera SA. Test work from samples indicated that an ore feed of 800ktpy into a flotation plant would include an antimony-bearing gold-rich concentrate, grading 38.5g/t Au, 114g/t Ag, 6.6% Sb and 29% As. The company notes that it is reviewing upgrading the antimony grade of the concentrate following the recent interest.

Antimony supply has been reshaped since the appearance of high volumes of gold by-product concentrates recovered from the Olimpiada gold mine in Russia in 2018. However, with the main revenues of Olimpiada geared toward gold, its owner Polyus has significantly dropped concentrate output since 2021. This has caused a material shortage of feedstock for ingot smelters in China facing declining domestic reserves.

Prior to the addition of material from Polyus, small-scale by-product antimony was increasingly being sourced from lode gold mines in Central and South America. This effectively stopped when Polyus flooded the market. Now, primary antimony-only mines and projects are facing high risks of entering (back) into production with a threat of 15% of global supply looming from Polyus. Can other gold by- or co-product projects leverage the supply deficit emerging in China? Talco Gold in Tajikistan is the only next major source of antimony coming online for China’s ingot smelters, supporting the trend of by-product growth.