About Copper Smelting:

• Copper, while an essential nutrient, is toxic to animals and humans in high concentrations.
• The main pollutants are released by the process of smelting.
• Most copper ores are sulphur-based and smelting releases sulphur dioxide, an air pollutant known to have many harmful effects.
• Sometimes, depending on the quality of the ore, the concentration of sulphur dioxide is so high that industries are forced to convert it into sulphuric acid, which itself is a water contaminant.
• The other byproduct of smelting is slag, the waste matter separated from metals. This slag may leach heavy metals (arsenic, cadmium, lead or mercury depending on the composition of the ore) into groundwater reservoirs.
• Water which has a high heavy metal content is very toxic to humans. Slag may also increase the concentration of other, less harmful salts in water resources, which may change the taste of water.
• The proper disposal of these byproducts can restrict the pollution caused by these factors to within the limits permitted by the government and other regulatory bodies.

Source:IE