During the year, Kenmare mined 23,951,200 tonnes of ore and produced 1,137,200 tonnes of HMC. 720,100 tonnes of ilmenite product were produced along with 31,400 tonnes of zircon, including 10,300 tonnes of secondary zircon product. Zircon production was lower than expected, mainly due to an extended shut-down of part of the processing facilities during commissioning.
Our new dredge and WCP B achieved design capacity during the second half of 2013, and the average throughput levels for the first couple of months of 2014 were at design capacity. Our new feed preparation plant, the Wet High Intensity Magnetic Separation (“WHIMS”) Plant, has been performing at planned throughput levels and the Auxiliary Ilmenite Plant reached design recovery levels within a couple of weeks of being commissioned.
However, sustained operation of these plants at design utilisation levels is subject to ongoing optimisation work and has been hampered by difficulties that the Mozambique state electrical utility, Electricidade de Moçambique (“EdM”), has been experiencing in achieving stable transmission of power. Electrical power at the Mine has been highly volatile over recent months, as a result of a combination of increased base load, electrical storm activity, and increased power demand in the Southern Hemisphere summer months, which has pushed demand towards the transmission network’s capacity limits, mainly at peak periods.
Kenmare has been working proactively with EdM in a number of areas to resolve these issues:
- Current and near term
A load management plan is being implemented by EdM, which is designed to prevent the load on the northern transmission network rising above stability limits at peak times. This programme has contributed to improvements in network stability. Additionally, Kenmare is working with EdM on a number of projects for the optimisation of the operation of the network to limit the frequency of supply interruptions.
- Short and medium term (one-year horizon)
EdM is enhancing the transmission capacity of the network by adding a set of series capacitors. These capacitors are expected to increase the capacity at Nampula from 118 MW to approximately 170 MW. This should allow several years’ load growth before capacity limits are approached again.
- Medium and long term (five-year horizon)
EdM is in the financing stage of a major project to add a new 400 kV line to the northern network, which should resolve power transmission issues for the long term future. EdM plans for this project to be completed by 2018.
I reported last year that Kenmare was installing a synchronous condenser (referred to as a “Dip Doctor”), designed to minimise voltage dips and sustain power. This was installed during the year and, when operating, is effective in reducing the effect of these dips. However, due to operational difficulties and storm damage, the availability of the Dip Doctor during January and February 2014 was lower than planned.
We have also been enhancing our standard operating procedures and equipment to minimise downtime caused by voltage fluctuation. This has been very successful in our mining and wet concentrator plants, where typical downtimes after a stoppage have been very significantly reduced to less than an hour. The expanded Mineral Separation Plant (“MSP”) is inherently more sensitive to voltage fluctuations and for the time being is taking longer to recover. Accordingly, we are dedicating additional resources to resolving this issue.
Kenmare has entered into a contract for the use of diesel generator units to supply power to the MSP. These will ensure stable power supply to the MSP during the summer months of December to March, when we encounter most of our voltage stability problems, and would act as a standby facility in case of failure of the transmission system during the rest of the year. More stable power supply will increase both the quantum and predictability of production.