Modern Mining June 2018

WEST AFRICA

by 9 % to 3,6 g/t compared to 3,3 g/t in the December 2017 estimate. Commercial production was achieved at Prestea Underground on February 1, 2018 and the mine pro- duced 7 481 ounces of gold in the first quarter of 2018 compared to nil in the first quarter of 2017. Challenges experienced with the blast- ing of the first stope at Prestea Underground (which were reported by GSR in January this year) continued during the reporting period. As a result, the blasted ore from the first stope contained higher than anticipated lev- els of dilution and the grade processed from Prestea

Prestea is located south-west of Wassa near the town of Prestea. Probably the most famous mine in Ghana after Obuasi, it started pro- duction over a century ago and has reputedly produced 9 million ounces of gold over its life. It was acquired by GSR in 1999 but placed on care and maintenance in 2002 while evaluation and exploration activities continued. Open-pit mining started in 2015. The five-year mine life of Prestea Underground is expected to be extended through exploration. GSR’s consolidated cash operating cost per ounce was US$909 in the first quarter of 2018, a 14 % increase compared to the first quarter of 2017. This was due primarily to the

Underground was 8,22 g/t Au, compared to the average mineral reserve grade of 12,35 g/t Au. GSR says the mining team has learnt impor- tant lessons from the first stope and further changes have been made to drill design pat- terns, blasting practice, raise layouts and stope ventilation in order to address these dilution issues. Since mid-April 2018, when GSR began drawing down ore from the second stope at Prestea Underground, the mine’s production rate has increased significantly (averaging 613 tpd in late April) and management expects the results of the second quarter of 2018 to reflect these improvements.

Underground at Prestea. Commercial production from the underground operation was achieved at the beginning of February this year.

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June 2018  MODERN MINING  43