In recent years the use of roasting as the traditional way of releasing gold values from refractory sulphides has been replaced by biological and pressure oxidation. In the biological oxidation process bacteria are used to oxidise the sulphides encapsulating the gold. These bacteria require a nutrient to optimise the process and Nowata have formed a joint venture with a Belgian company to manufacture these reagents. The required elements, nitrogen, phosphorous and potassium are varied depending on the ore composition.
Jun 21 2013