How do oxygen and oxygen-enriched air help smelt copper concentrate?

In modern copper smelting, the use of oxygen or oxygen-enriched air is central to flash and bath smelting processes, which have largely replaced traditional methods that required auxiliary fuel.1

When dry copper concentrate and flux are contacted with a blast of oxygen or oxygen-enriched air, the iron and sulfur present in the concentrate undergo oxidation. These reactions are highly exothermic, meaning they generate sufficient heat to smelt the concentrate into a liquid matte and slag without the need for external fuel.1

Beyond reducing fuel consumption, this approach offers significant environmental and operational advantages:
* Efficiency: Smelting can be carried out autogenously, relying on the heat from the oxidation of iron and sulfur.1
* Emission Control: The process produces relatively low volumes of gas that are highly concentrated in sulfur dioxide, making it ideal for the production of sulfuric acid.1
* Capture Rates: Modern smelters utilizing these oxygen-based processes are designed to capture 90 percent or more of the sulfur contained in the feed materials.1