DIAMOND MINING – Diavik mine performing above expectations

NORTHWEST TERRITORY - The Diavik diamond mine produced approximately 3.3 million ct of diamonds during the second calendar quarter compared with around 2.7 million ct for the comparable period a year earlier. Production for the first half of the calendar year was almost 5.9 million carats. This is well ahead of the current plan and principally the result of higher recovery of diamonds per tonne of ore processed.

Operating experience has shown that the tonnage of A-154 South pipe to date has been on the order of 10% greater than the resource block model. The increases in grade will deliver higher annual carat production while the increase in tonnage will have a positive impact on the mine life. The increase in diamond recovery is a due primarily to improvements to the processing circuit.

Work on a new mine plan is nearing completion. It will schedule underground mining for at least three of the four kimberlites. The final version of the plan will incorporate diamond price information from underground bulk samples from A-21 and A-154 North. The A-154 North sample was collected in two aliquots. One was mined using conventional drill-blast techniques while the other was extracted using a road-header or mechanical mining machine. The results will be examined for any recovered grade (carats per tonne) or diamond quality (dollars per carat) differences between the two mining techniques.

The new plan will be reviewed by the boards of partners ABER DIAMOND (40% owner) of Toronto and RIO TINTO (60% owner and operator) of London, U.K. towards the end of this year. Readers may want to check the available job openings at the Diavik mine at www.Diavik.ca.