Tackling the fjords of Norway would be daunting to any one, in any discipline. The ancestral terrain of the Vikings, however, proves especially intimidating for the mining industry, which is constrained by regulations in the use of chemicals in Scandinavias glorious geographical wonder.
Yet, the Norwegian coastline possesses abundant mineral deposits, including gold, and it would be a shame to be unable to recover the wealth drizzling from across its rock. When a major player in efforts to mine the area approached Peacocke & Simpson about how to go about extracting minerals from ore, our team was up to the challenge.
Following flowsheet development, we worked with Gexco Limited on its plant installation in Norway. This stage needed particular care and attention to detail because the objective was not only the recovery of gold, but also the sulphide mineral, too. Although driven by the need to satisfy the environmental criterion of a low-sulphur discharge, the sulphides were also found to be valuable in their own right as gold carriers. These requirements for a clean, environmentally friendly solution meant that Gexco would have to rely completely on gravity concentration a chemical-free process to economically recover the minerals.
The flowsheet was designed around the existing crushing and milling circuit and two state-of-the-art Knelson concentrators were added. The first, the Knelson CD batch concentrator, was tasked with the recovery of the liberated elemental gold. The tailings from this device then flow to a Knelson CVD continuous concentrator to recover the liberated sulphides. The way in which these two devices are incorporated into the circulating mill load results in mineral being recovered as soon as it is liberated, without unnecessary and wasteful overgrinding.
Results of pilot-phase testing showed that the circuit was capable of recovering over 88% to concentrates, even before final optimization. This very credible result confirms the bold choice of this unusual processing method.
Our endeavour with Gexco has been a success. In 2007, the company applied for approximately 600 additional exploration permits as it expanded its Norwegian operations, which are based in Mo i Rana.
There is a vast amount of mineral wealth in the land of Thor that has yet to be explored and our Scandinavian friends are in prime position to prosper. We are proud that Gexco chose Peacocke & Simpson for this project, not only for the metallurgical challenge, but also for the chance to demonstrate a shared commitment to this glorious nations fragile resources. Producing leading processing solutions while maintaining a regard for the environment continues to be a Peacocke & Simpson hallmark.