Starfield Resources has funded the development of an innovative hydrometallurgical process to recover metals from its Ferguson Lake massive sulphide ore.
The hydrometallurgical process is unique in that it recovers most of the metals (nickel, copper and cobalt) and turns typical problem elements (sulphur and iron) into marketable byproducts. The process also has another unique byproduct – 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 byproducts instead of pollutants, Starfield and its consultants have developed a very revolutionary process.
Good for Starfield Resources; Great for the Environment
Conventional milling and flotation processes generate toxic and acid-producing tailings which need a dedicated disposal area with perpetual monitoring.
Starfield’s hydrometallurgical process turns the typical problem elements of sulphur and iron into saleable byproducts. Iron is converted into hematite, which is non-toxic and potentially marketable. Sulphur is converted into sulphuric acid, which is a necessary reagent in the recovery of uranium metal, and is also used in the manufacture of many commercial chemicals and fertilizers.
The Heat is On
As shown in the Block Flow Sheet below, the Primary Leach process outputs hydrogen sulphide gas (H2S). The H2S gas is reacted with oxygen, resulting in the release of extreme heat (1600°C) and sulphuric acid (H2SO2). The extreme heat is captured to produce super-heated high pressure steam sufficient to power steam-driven electrical generation.
The ability to produce our own energy is a tremendous savings to both our costs and the environment. With an expected ore feed of 6000 tonnes/day, the Primary Leach Process generates 65 tonnes/hour of H2S. Burning the H2S provides 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.
Hydrometallurgy is truly a win/win situation!