The copper smelting market can be segmented based on process, end-user, and region. Based on process, the copper smelting market can be divided into reverberatory smelting, oxygen flash smelting, acid plant, tapping-the-flash furnace, converter furnace, and others. Reverberatory smelting and oxygen flash smelting are methods that require the resultant molten copper to be further processed to attain 99.9% pure copper. The gas emitted during the process is converted into sulphuric acid, which can be used within the plant or sold as a byproduct. A reverberatory furnace is fabricated from steel beams into a rectangular structure which is lined outside and inside with firebricks. Fossil fuel- and/or oxygen-fired burners provide exothermic heat required to melt the copper ore, which is supplied by the conveyor to the gas-tight hopper. A reverberatory furnace has a tapping point for molten copper and slag. There is normally a waste heat boiler incorporated in the reverberatory furnace, as a large amount heat is utilized in this smelting process.