Gold ore is crushed and ground to liberate gold particles from the surrounding material.

The ground ore is subjected to various processes like gravity separation, flotation, or cyanidation to concentrate the gold.

Several methods can be used:

 * Aqua Regia: A mixture of hydrochloric and nitric acids dissolves gold, separating it from other metals. Gold is then precipitated out of the solution.

    * Electrolytic Refining: Impure gold is made the anode, and pure gold the cathode in an electrolyte solution. When an electric current is applied, pure gold deposits on the cathode.

    * Miller Process: Impure gold is melted and chlorine gas is blown through the liquid. Chlorine reacts with impurities, forming a slag on the surface that is removed.

Refined gold is melted again and cast into final shapes, such as bars or ingots, with high purity levels, often 99.99% or higher.