Mining & metallurgy, a contaminated mine water is generated when rock containing sulphidic minerals is exposed to water and oxygen, resulting in the production of acidity and high concentrations of metals and sulphate in the water. The impurities are oxidised to form gaseous oxides of carbon or sulphur taking the metal bath towards the final steps of refining. Aiming at increasing the productivity, the converter operation is trimmed to have high chemical reaction rates and efficient heat and mass transfers. Gas phase-liquid metal reactions are optimised. Thus, converters form an essential, integral part of metals production. While some authors attribute the concept of converters to ancient asiatic scriptures, dating back to eleventh century C. E., the present form of converters was probably evolved with the famous patent of Henry Bessemer in the year 1856 (American inventor William Kelley has earlier been experimenting with blowing air to decarburise iron melts). The invention of the vertical reactor for decarburisation by air blowing has, in fact, revolutionised steelmaking and geared up the production rate.