Environmental Impacts and Emissions from Roasting Compared to Calcination

Both calcination and roasting release gases that can have environmental impacts. The differences in their emissions largely depend on the materials being processed.

Emissions from Calcination

• Carbon Dioxide (CO₂): Calcination of carbonate ores releases CO₂, contributing to greenhouse gas emissions. Example: Calcination of limestone releases CO₂ into the atmosphere.
• Low Sulfur Emissions: Since calcination often occurs in a limited oxygen environment, sulfur emissions are typically lower compared to roasting.

Emissions from Roasting

• Sulfur Dioxide (SO₂): Roasting sulfide ores produces SO₂, a significant air pollutant that contributes to acid rain. Efforts are made to capture this gas, but it remains a major concern.
• Particulate Matter: Roasting also releases particulate matter, which can cause air quality issues in industrial areas.