Jericho nets higher grades during tests

Nunavut's first diamond mine, Jericho, operated by Toronto-based Tahera Diamond Corp., is still undergoing technical improvements aimed at increasing output and turning losses into profits. The value of the mine's production for the second quarter of 2007 was US$6.4 million, for a total cash operating cost of $16 million, Tahera said in a release Aug. 7. Jericho processed 95,500 metric tons of ore in Q2 at an average grade of 0.78 carats per ton, resulting in production of 74,000 carats.

Overall, total tons processed at Jericho decreased by 42 percent compared to the first quarter, mainly due to the plant testing that was completed during the second quarter, Tahera said. The grade increased by 73 percent compared with the first quarter, as a result of upgrades to the plant and an improved mix of material. Screen panels were reduced from 1.25 millimeter apertures to 1 millimeter to capture smaller stones. Mining efforts focused on waste stripping, resulting in the exposure of the 430-meter bench level.

1,500 tons per day

Tahera also conducted audits on its existing processed kimberlite, and 13,455 tons of material yielded 3,170 carats, for a grade of 0.236 carats per ton. These fairly small diamonds were valued at about $38 per carat. "Having carats in your tailings means that it's a processing issue and that we can remedy that and collect those tails and generate revenue on the margin," Peter Gillin, Tahera's chairman and CEO, said in a conference call Aug. 8.

Throughput at Jericho in the second quarter was approximately 1,500 tons per day, and Tahera hopes to increase it to 2,000 tons per day over the next few months. "We intentionally scaled back the throughput in order to conduct these tests ... so we didn't have the overall tonnage in the quarter that we had anticipated," Gillin said. "Clearly this is not where we want to be. ... We are now going to slowly elevate the throughput in order to ideally maintain the grade output, therefore ultimately increase the cash flow by way of doing that."

Tahera recently appointed Michael Johnson as interim director of operations at Jericho. Johnson has been involved with the exploration and data analysis of the Jericho kimberlite for the past nine years, including contributing to the development of the feasibility study, and has been Tahera's exploration manager since 2002.