Caledonia invests in improving operational sustain...

Caledonia invests in improving operational sustainability

Mining Weekly - Caledonia Mining is investing into its flagship asset, Blanket Mine, to improve the mine’s sustainability and ensure continuous operations.

Blanket mine achieved Caledonia’s long-term yearly gold production target of 80 000 ounces(about 2268 kg) in 2022 and the miner is taking steps to ensure it can continually mine the resource on a sustainable basis.

These efforts include steps to stabilise grid electricity, the establishment of a solar photovoltaic power plant and installing of backup diesel generators to meet the mine’s power needs when during load shedding and periods of unstable supply.

If not controlled, Caledonia says power surges experienced at Blanket can cause severe damage to the mine’s electrical equipment.

Power surges are regulated by autotap transformers that are installed to normalise fluctuations up to 10 MVA, but the miner says current fluctuations vary up to as much as 12 MVA.

As a result of load shedding and low voltage occurrences, two 10 MVA autotap transformers were installed in the fourth quarter of 2021. This reduced the voltage fluctuations and reduced the power cost by lessening the use of diesel for backup generators.

Blanket’s use of diesel for generating electricity – assets which can supply the whole mine with electricity – decreased from about 3.31-million litres in 2021, to 1.42-million litres in 2022.

To mitigate against the current power shortages, Caledonia has constructed a 12.2 MW solar plant at a cost of about US$14.3-million (including construction and other project planning, structuring, funding and administration costs), supplying the Blanket operations.

The solar plant was fully commissioned early February this year, and provides about 27% of Blanket mine’s average daily electricity demand. The plant has been providing power to Blanket from its initial connection in November 2022.

In 2020, Caledonia raised US$13-million (before commission and expenses) through the sale of 597 963 shares at an average price of US$21.74 apiece to construct the solar plant.

In another effort to improve its access to electricity, Caledonia’s management is in discussion with the Zimbabwean power utility to obtain an improved supply of electricity.

This may include an additional supply line that will result in fewer outages and a power supply that has a higher power factor. Blanket may potentially pay a different kW/h rate for this supply line.

Further, Caledonia’s board has allocated about US$3-million towards a capital programme to address the remaining issues relating to the electricity supply from the grid, which includes installing capacitors to improve power use efficiency and installing further autotap changers to stabilise the power at Blanket’s Central Shaft.

Caledonia is also investing resources into a main capital development project to establish and improve infrastructure.