The initial development for a revolutionary hydrometallurgical process to recover metals began from the Ferguson Lake massive sulphide ore deposit in Canada, the process being unique in that it recovers the metals (nickel, copper and cobalt) and turns typical problem elements (sulphur and iron) into marketable by-products. The process also has another positive output – energy. In fact, sufficient energy is produced to power the production plant and the mine, with some excess power remaining for potential sale to local communities.
By capturing the sulphur and iron in an environmentally acceptable form, and transforming it into by-products instead of pollutants, these type of refractory sulphides have enormous potential to become a world class deposit.
Good for resource owner; Great for the environment
Conventional milling and flotation processes generate toxic and acid-producing tailings which need a dedicated disposal area with perpetual monitoring. This hydrometallurgical process turns the typical problem elements of sulphur and iron into revenue stream. Iron is converted into high purity hematite, non-toxic and marketable. Sulphur is converted into sulphuric acid, a necessary reagent in the recovery of uranium, and is also used in manufacture of many commercial chemicals and fertilizers.
The Heat is On
The Block Flow diagram is shown below. The ability to produce own energy is a tremendous savings to both project economics and the project environment. With an expected ore feed of 6000 tonnes/day, the Primary Leach Process generates 65 tonnes/hour of ‘feed’, providing 1,000,000 MJ (megajoules)/hour of energy.
How much energy is 1,000,000 MJ/hour? To produce the same amount of energy using fuel oil would require 24,000 litres/hour. At $0.90/litre of fuel oil, that’s a cost saving of $21,600/hour! And that doesn’t include the costs of shipping vast amounts of diesel fuel to the production plant or mine.
What’s the bonus to the environment? Not using 24,000 litres/hour of fuel oil, prevents 60 tonnes/hour of CO2 greenhouse gases from being emitted into the atmosphere.
