You probably already know that the Micronics Engineered Filtration Group is a proven leader in filtration solutions for the mining and mineral processing industries. One of the application areas that we have long-standing expertise in is the Merrill-Crowe process, which is a separation technique for removing gold (or silver) from a cyanide solution by zinc precipitation.
The basic process was discovered and patented by Charles Washington Merrill around 1900, and later refined by Thomas Bennett Crowe, working for the Merrill Company. Though there are many, many innovations in the mining and mineral processing arena, to date, no method has yet to be found that is able to compete effectively with the Merrill-Crowe Process for recovering the metallic values from cyanide solutions.
Micronics’ advanced filtration solutions for Merrill-Crowe include but are not limited to the following capabilities and considerations:
- Specialized high-flow filter presses designed and engineered by Micronics specifically for the Merrill-Crowe process. Materials of construction are selected to ensure that everything the gold slurry comes in contact with is suitable to the Merrill-Crowe gold (or silver) recovery application.
- Specialized plates designed specifically for the Merrill-Crowe process. These special plates employ a larger, more oversized centerfeed larger feed eyes, and filtrate porting to accept the higher flows associated with this process.
- The filter presses are usually pre-coated with diatomaceous earth or perlite at the beginning of the filtration cycle. The amount and type of precoat will be a function of variables such as the ore type.
- The filter cloth, plates, and filter press piping specifications are all selected to withstand the high pressures and velocities of the Merrill-Crowe Gold Recovery Process.
- Typical filtration flow rates range from .56 gpm/ft2 to 1.0 gpm/ft2.
- Merrill-Crowe installations almost always have one standby filter press, in addition to the operating press, to ensure optimal efficiency under very demanding, high-flow conditions. Having two filters allows one to go online while the other is being cleaned, precoated, etc. Micronics works closely with the customer to ensure the most efficient, effective filtration operations to help achieve the customers’ operating objectives and maximize up-time.
- Micronics offers a range of options for shifting; typically, our Merrill-Crowe presses employ semi-automatic hydraulic shifters with air-over-oil hydraulics though fully automatic electro-hydraulic shifters are often employed.
- To collect the filter cake that is discharged, Micronics offers convenient, rugged cake carts that are well-suited to supporting the Merrill-Crowe process. Cake blow is often employed as well to further remove cake moisture.
Contact us and benefit from Micronics’ extensive advanced filtration solutions expertise for mining and mineral processing including processing tailings, mineral concentrates, and the high-flow Merrill-Crowe process for gold recovery. We supply high-quality filter cloth for all makes and models of mining presses, so contact us for all your replacement cloth needs. When it comes to mining and mineral processing, Micronics has you covered with expert filtration solutions.