RIO TINTO Plc’s 78% owned Zimbabwean diamond producer, Murowa Diamond Mine (Murowa), reported a 7% growth in diamond production to 344 000 carats in 2014 compared to the prior year owing to an increase in ore processed, latest company figures show.
Murowa processed 590 000 tonnes of ore in 2014, up from 564 000 tonnes the previous year and recovered 442 000 carats in the year under review, up from 414 000 carats in 2013.
The company’s share of production at Murowa amounted to 101 000 carats in the fourth quarter of 2014, 12% higher than the previous quarter and 4% less than 2014 fourth quarter figures.
Total diamond output for the year-including that of its 60% owned Canadian mine Diavik and its wholly owned Australian producer Argyle Mine stood at 13,9 million carats, down from 16 million carats prior year.
Argyle recovered 9,2 million carats during the year , 19 % lower than in 2013, reflecting the move from open pit to underground mining and the processing of lower grades as underground production ramped up.
“In addition, a maintenance shutdown took place during the fourth quarter to implement some improved design modifications to both underground crushers,” said Rio Tinto.
Diavik’s annual production was flat at 4,3 million carats, with improved mining rates and processing plant improvements offset by the impact of lower grades, said Rio Tinto.
“Carats recovered in the fourth quarter were significantly lower than in the previous year as improved processing rates have now fully exhausted the stockpiled ore which was processed in prior quarters,” said the company.
The group said pre-tax and pre-divestment expenditure on exploration and evaluation charged to the profit and loss account in 2014 was US$765 million compared with US$948 million in 2013, building on the savings achieved in 2013 while pushing the high priority projects.
Rio Tinto’s diamonds and minerals division accounted for 15% of the US$765 million spent on exploration and evaluation while the copper group incurred approximately 33% of the expenditure.
The company said drilling for diamonds continued in India on a number of targets. In Canada, data review and sampling of several targets was completed.
The iron ore and energy divisions accounted for 5% and 18% of the expenditure respectively.