PERTH (miningweekly.com) – ASX-listed Tiger Resources has downgraded its copper cathode production expectations for 2016, following the seepage of process solution from its intermediate leach solutions (ILS) pond at the Kipoi project, in the Democratic Republic of Congo.
The miner said on Tuesday that the leak was discovered on October 15, with the ILS solution exiting the pond wall at the top of the eastern embankment. All flow to the ILS pond was ceased and a diversion trench was excavated to divert the flow to the process pond.
It is estimated that between 10 m3 and 30 m3 of ILS solution was released, but Tiger noted that this solution had been neutralised with lime and recovered to the site waste disposal area. The source of the leakage was also repaired and solution seepage from the ILS pond had ceased.
Environmental officers have checked downstream monitoring bores and detected no contaminants, while consulting engineers have conducted a full assessment of the cause of the leakage and the structural integrity of the ILS pond.
Tiger told shareholders that work was under way to reinforce the existing ILS pond walls and to pump out solution trapped under the high-density polyethylene liner. The work was expected to take up to six weeks, and production during this time was expected to average between 55 t/d and 60 t/d of copper cathode.
As a result of this work, Tiger has downgraded its full-year production expectations from between 25 000 t and 26 500 t, to between 23 000 t and 23 600 t.
Cash operating costs for the full year would also increase from the initial estimate of between $1.40/lb and $1.46/lb, to between $1.49/lb and $1.52/lb.
Meanwhile, a new ILS pond is being constructed as a permanent replacement and will likely be commissioned during the first quarter of 2017.