Diavik Diamond Production Exceeds Expectations


Source: Aber Diamond Corp.
Diavik Diamond Mines Inc., operator of the Diavik diamond mine in Canada’s Northwest Territories, reported that approximately 3.3 million carats of diamonds were recovered from the mine during the second calendar quarter compared with around 2.7 million carats for the comparable period last year. Production for the first half of the calendar year was almost 5.9 million carats. This, according to the company, is well ahead of the current plan and principally the result of higher recovery of diamonds per metric ton of ore processed.

According to Diavik, the substantial increase in diamond recovery is a combination of improvements to the processing circuit to enhance the recovery of small diamonds as well as, to a lesser extent, recovery of larger stones that were not anticipated by 1994-1995 large-diameter core sampling which formed the basis of the resource model. Similar improvements in recovered grade are expected for all of the Diavik reserves and resources but to differing degrees for the various geological units of the different kimberlite pipes.

Diavik said operating experience has shown that the volume, and therefore tonnage, of A-154 South mined to date has been about 10% greater than the resource block model for this pipe. However, it is unknown whether this factor will persist at depth in A-154 South, or in the other pipes making up the Diavik resource. The increases in grade will deliver higher annual carat production from the project mining and processing capacity while the increase in tonnage will have a positive impact on the mine life.

Work on the new mine plan is now nearing completion. It will be reviewed by the boards of Aber and Rio Tinto toward the end of this year. The new mine plan brings underground mining of at least three of the four kimberlite pipes into the production schedule. 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 portions, or aliquots. One was mined using conventional drill-blast techniques while the other was extracted using a road-header. The results will be examined for any recovered grade (carats per mt) or diamond quality (dollars per carat) differences between the two mining techniques. Since Aber and Rio Tinto do not disclose diamond pricing information to each other, Aber plans to have the bulk sample diamonds valued independently for public reporting purposes.

The Diavik mine, Canada’s second largest, is a joint venture between Aber Diamond Corp. and Diavik Diamond Mines Inc., a wholly-owned subsidiary of Rio Tinto plc. Under Aber's joint venture agreement with DDMI, Aber pays 40% of the operating and capital costs and has the right to receive and market 40% of the diamond production, but does not operate the mine.