Gold is mined in the form of microscopic particles in concentrations as little as 0.5 parts per million (ppm). As a result, simple tools have been replaced by complex equipment and chemical processes to extract gold. Today, one of the most popular methods for gold extraction is the Merrill Crowe process.

The process can be summarized as follows:

• The zinc, cyanide and gold ore are mixed
• The gold has an affinity to the zinc and cyanide particles and forms deposits on the surface of the zinc
• The zinc and gold particles are then filtered out using a filter press that has precoat of diatomaceous earth or perlite

Evoqua’s filter presses are the natural choice for remote operations with demanding conditions, where rock-solid dependability is paramount. They feature application-specific designs for the precise requirements of the Merrill Crowe process.