ABSTRACT
This chapter discusses the halide leaching of gold and the chlorination process, and the cyanidation. Despite being highly toxic, the cyanide leaching of gold is the most common technique in the exploitation of gold from its ore bodies. Vat leaching is used for high grade ore processing, in which the ore slurry is treated under agitation in large tanks containing the solution of sodium cyanide. An amalgam is simply an alloy of mercury with gold, and the process of amalgamation has been in practice for thousands of years to recover the precious metal of finer size. Due to stringent environmental rules and regulations with more and more concerns regarding public health and the aquatic system, there is immense pressure on the gold mining and metallurgy industry to reduce its environmental footprint. Although more sustainable process and technologies are being developed, there needs to be more information about their direct and indirect impact on the environment during different processing steps.
