Complex sentence: Typically, this process blows compressed air through the tailings while adding sodium metabisulfite which releases SO 2, lime to maintain the pH at around 8.5, and copper sulfate as a catalyst if there is insufficient copper in the ore extract.
Split into simpler sentences: Typically, this process blows compressed air through the tailings while adding sodium metabisulfite, which releases SO 2. Lime is used to maintain the pH at around 8.5, and copper sulfate is added as a catalyst if there is insufficient copper in the ore extract.