Neves-Corvo Copper Mine, Portugal, is located100km north of The Algarve and is owned by the Canadian Lundin Mining Corporation. Lundin is a diversified base metals mining company with operations in Portugal, Spain, and Sweden, producing copper, nickel, lead and zinc. In addition, Lundin Mining holds a development project pipeline which includes expansion projects, at its Zinkgruvan and Neves-Corvo mines, along with its equity stake in the world class Tenke Fungurume copper/cobalt project in the Democratic Republic of Congo.
The Neves-Corvo Mine is operated by the Somincor Mining Company and is an operational underground copper and zinc mine in the western part of the Iberian Pyrite Belt which stretches through southern Spain into Portugal. The mine access is provided by one vertical 5 metres diameter shaft, hoisting ore from the 700 metre level, and a ramp from surface.
The mine has been a significant producer of copper since 1989, employing both bench-and-fill and drift-and fill stoping methods underground. The ore treatment is carried out by conventional crushing, flotation, grinding, thickening and filtration processes. The copper plant treats up to 2.2 million tonnes of ore each year producing high grade copper concentrate mainly for the export market.
As part of the process, they need to store tailings pyrites in a 190 hectare dam, 3 km from the mine itself and water from the dam is used in the industrial process. In order to balance the very high pH levels in the dam, between 10 and 20 tonnes of lime needs to be introduced into the system each day. As a result, 3 pipes of between 35cm and 40cm diameter feeding the industrial tank required constant chemical and mechanical cleaning. Various methods of cleaning had been tried, including injecting CO2 directly into the pipes. This was carried out by a sub-contractor and took around 4 months to clean just one pipe. The inside bore of these pipes had fouled so heavily that at times, they had reduced to just 7cm in places.
In November 2007, engineers from ETC
’s Portuguese Agent, TAI-Ibérica, installed ENiGMA
Electronic DeScaling units onto the three feed pipes from the dam and another was fitted onto the single pipe feeding associated header tanks. In June 2008, the first pipe to be treated was opened for maintenance and the engineer found that the problem had been reduced to a very light deposit of powder which was cleaned simply by washing it with clean water.
As a result of the ENiGMA
treatment, both the amount of fouling and the time taken to clean the pipes have been dramatically reduced. Now the small amount of scale that builds up inside the pipes is much softer and easier to remove.
Somincor Engineer Dr Mafalda Oliveira, who is responsible for the Dams and water, said “We are very happy with the ENiGMA
system from TAI-Ibérica. It has proved to be as effective for treating our hard water problems as they promised and we expect to make substantial savings in reduced maintenance costs alone”.