Lime Roasting Of Pyrite

Tube furnace experiments have been performed to evaluate the lime roasting of pyrite in air. The sulfur volatilized was measured over time. Variables studied included: form of lime, sodium sulfate additions, temperature, air flow rate, lime to pyrite weight ratio and pyrite particle size. It was found that more than 98% of the sulfur can be retained at a reactor temperature of 650°C, with a slight excess of calcium hydroxide. The roast products are primarily hematite and calcium sulfate.