Production
As expected, Kayelekera showed a significant quarter over quarter improvement in production resulting from continued plant debottlenecking and mine-wide material handling improvements. In the June quarter, production totalled 515,478lb U3O8, an increase of 125% over the preceding quarter. Kayelekera production ramp-up, although slower than initially forecasted, has produced a steady improvement in performance. June production for the first time exceeded 200,000lb while further improved operations are expected to continue this positive trend.
Through June the 3rd party efficiency group that assisted with the ramp-up performance/process improvement programme was expanded to incorporate maintenance and procurement activities in order to streamline this part of plant operations. This extended initiative is proving highly successful ensuring both sustained and continual increases in the production value chain and in the production support activities. Ongoing training of staff has led to an improved level of cohesion and teamwork within the operation. These activities are expected to assist KM reaching targeted operating efficiencies earlier than scheduled.
Commercial Production
As previously foreshadowed, the plant operated at its design capacity for significant periods during June 2010. Based on this performance the plant has proven operations at up to design capacity and is producing commercial quantities of uranium that meet specification. Consequently, the Company has taken the decision to declare that the Kayelekera Mine is in commercial production from 1 July 2010 and that no further costs will be capitalised after 30 June 2010. This represents another significant milestone achieved by Kayelekera.
Mining
Mining activities at Kayelekera are currently dictated by production ramp-up progress. The mining schedule effectively maintains a 3 month supply of feed ore at the ROM pad sorted according to grade and physicals (mudstone, arkose) as well as separating oxidised and non oxidised ore while the pit is being mined near surface. The contractor has proven capable of handling design feed levels, particularly in June where feed levels often exceeded design tonnages.
Mill feed to the plant has purposely been blending at a higher percentage of arkose vs mudstone resulting in a slightly higher feed grade to the plant than the 1,350ppm budget numbers. The plant’s material handling capabilities have improved significantly and management expects feed grade to average budgeted numbers in the September quarter.
Process Plant
The mechanical downtime of various circuits has improved significantly in the June quarter and continuous improvement is expected to increase plant availability further. All plant circuits (crushing, milling, leach, RIP contactors, precipitation and drying), with the exception of Resin Elution, have shown that they are now capable of operating at design rates or higher, including mechanical availabilities. There is a minor issue with the solution flow rate through elution, which is currently being addressed.
The crushing plant, now able to utilise both a mineral sizer and jaw crusher, is operating well with impacts on the operation at a minimum.
Leaching continues to perform reasonably, increasing from 76% in April to 84% in June, although improvements to extraction rates are expected as reagent dosing control is optimised. Efficiency in RIP averaged 86% for the quarter.
The back end of the plant (uranium precipitation and packaging) underwent a number of optimisation initiatives including a change out of the drying centrifuge. The capacity in this circuit is now at a level where the section can operate well above design.
Throughout the June quarter, operational efforts successfully brought tonnages and uranium feed consistently higher.
Post Quarter Trends
As described earlier, Kayelekera has produced consistent monthly increases in production levels. During the last weeks of the quarter and the first 10 days of July, uranium feed to RIP has been approximately 11,000lb (U3O8 basis) per day (nameplate is 9,040lb per day), with RIP efficiencies averaging in the high 80%’s, and regularly exceeding 90%. Management is confident that consistent design production levels of 275,000lb per month will be the norm for the forthcoming quarters.