Continental Gold Inc. has announced positive assay results for ore extracted from trial mining test stopes at the Buriticá project, Antioquia, Colombia. Two vertically-stacked stopes located along the HW vein in the Yaraguá system, at a midpoint elevation of 1525 RL measuring 20 m along strike by 35 m vertically by 2.60 m wide, were mined using the mechanised long-hole method. All extracted ore was systematically and thoroughly muck sampled and assayed with final results being significantly better than the mineral resource block model estimate on grade, tonnes and ounces.
CEO of Continental Gold Inc., Ari Sussman, commented: “This is an impressive outcome as it is the second trial mining test completed by the company and both have yielded significantly more ounces of precious metals than we estimated from the mineral resource block model.”
“Importantly, the vertical extent of ore extracted from the combined stopes is approximately 5 m longer than the feasibility study design for the project and as a result, our team is planning to evaluate designing larger stopes for production in 2020, which in turn would potentially reduce the amount of total underground development required.”
This is the second trial mining test conducted by the company with final results being significantly superior to the estimated results (the initial trial mining test results were announced on 3 May 2016 with 2093 oz of gold extracted from 2090 t of material grading 31.1 g/t gold versus an estimated 1033 oz of gold from 2022 t of material grading 15.9 g/t gold).
The actual tonnes mined was 27% greater than the design estimate due to the contact between mineralisation and waste rock being wider than the block model estimate and not due to excess dilution. The break along the contact was clean.
The combined vertical dimension of the two stacked stopes was approximately 5 m higher than the stope design dimensions outlined in the 24 February 2016 Buriticá project Feasibility Study. The next iteration of the mine plan will evaluate extending the vertical dimensions of the stopes, which should provide greater flexibility in the underground mine design and potentially reduce upfront underground development.
According to the company round control measures and safety protocols used were good and provided valuable training for their employees.
The company has batch processed, through its 30 tpd Yaraguá mill, approximately 10% of the mined ore from the trial mining stopes. Results are anticipated in January 2018.