Browsing by Author "Agyeman, Stephen Akore"

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    An economic analysis of ore dilution at the east limb stopes of Tarkwa Goldfields Limited
    (1990) Agyeman, Stephen Akore
    Hundred percent (100%) extraction at 0 percent dilution is an ideal mining efficiency. This is hardly achievable for reasons ranging from around stability problems to poor quality of mining practice. The total effect of dilution cannot be easily estimated due to a number of uncontrollable factors. Quantification of the dilution levels, however, gives a fair indication of how much extra cost is incurred and how much revenue is lost for mining the extra tonnage of waste. The study therefore aimed at quantifying and analysing the dilution levels from the East Limb stopes in terms of tonnage, percentage and costs incurred and revenues lost. This was done by using mainly classical statistics. At the East Limb of Tarkwa Goldfields Limited dilution has been found to be 17.34% as against the 10% expected from the stopes and the trend appears to be worsening, 16.70% in 1983 and rising to 24.65% in 1989. These indicated a revenue loss of over ¢46M and an increased cost of over ¢18M in 1989 for mining and milling the extra tonnage resulting from dilution above 10%. The cost would even 1e higher when the total mine costs are considered. It is certainly impossible to totally eliminate dilution. However, it could be reduced and controlled within the “economic” limits of the mine operations
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    Mine accidents – a case study at Teberebie Goldfields Limited, Tarkwa
    (2003) Agyeman, Stephen Akore
    Two fatalities in six months and a hundred percent increase in the number of accidents from 1996 (56) to 1998 (107) have been a source of worry for Teberebie Goldfields management. Effective accident prevention measures, however, required a study of the accident trends at the mine to identify the problem areas. The objective of this case study at Teberebie Goldfields Limited is therefore to analyse the mine accident data with a view to highlighting trends that would have much relevance in promoting accident-free mine operations at other surface mines operating under similar conditions. Relevant data was collected and analysed in terms of accident types, age brackets, activity and period. The study revealed that lack of experience, seasonal effects and social factors accounted for the high rates of accidents at Teberebie Goldfields. It is recommended that increased supervision, safety audits and inspections and intensified training could be used to reduce accidents at other mines operating in similar conditions.