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the merrill crowe process

Evoqua's J-Press filter press designed for the Merrill Crowe process is renowned for its rugged dependability.







 The flow rate through a filter plate designed for the Merrill Crowe process is designed to handle a much higher flow rate than typical filter plates.



 The Hi-Flow Plate for Merrill Crowe is designed specifically for this process. The centerfeed is oversized to accomodate high velocity throughput, as are the feed eyes. And instead of the usual 4 stay bosses, the filter plate for Merrill Crowe is designed with 8 to withstand the increased pressure and to maintain rigidity.


 We take great care to make sure that no brass, bronze or galvanized parts are used on the machines in areas that may come in contact with the pregnant gold solution. Everything the slurry comes into contact with is suitable for the application.

​Filter Press For the Merrill Crowe Process


The Evoqua J-Press filter press has a 40 year legacy of providing simple yet exceptionally effective filtering technology industry-wide. For nearly 30 of those years Evoqua filter presses have been used in multiple mining processes for both production and wastewater streams. Known the world over for unsurpassed performance under the most demanding conditions, the J-Press continues to be the natural choice for remote operations with little infrastructure and where rock-solid dependability is paramount.

Since our first Merrill Crowe installation, Evoqua has been building presses specifically designed for the precise requirements of this critical application. Evoqua’s filter presses for Merrill Crowe feature application-specific designs for filter plates, operating pressure and manifold piping. Through the use of specialty filter papers or media precoats, Merrill Crowe filter presses are designed to capture particulate as small as 0.5 microns. In order to provide the optimal filter press to meet your specific needs, we offer multiple choices for customization, including:

• Systems ranging from completely manual to fully automated

• Flexible press and plate sizes to suit any installation flow requirement

• Plate and frame for use with filtration papers

• Recessed chamber for use with precoat materials

• A full range of ancillary support equipment, including precoat systems, feed pumps, cloth wash, conveyors and control systems.

Capturing Particulates With High-Velocity Throughput

Evoqua filter presses for Merrill Crowe may utilize plates and frame filter plates that are fitted with polypropylene filter cloths covered by disposable filter paper for maximum particle retention. Alternatively, the filter presses may be equipped with recessed filter plates and cloths and are precoated with diatomaceous earth or perlite at the beginning of the filtration cycle. Zinc powder may be added along with the precoat to ensure that the gold is completely removed from the pregnant solution during the start-up of the precipitation/filtration cycle.

The J-Press for Merrill Crowe is operated at much higher flow rates per unit filter area than is typical for a standard filter press, and features a larger feed inlet, larger feed and filtrate ports in the filter plates, and a larger filtrate piping manifold. The manifolds are designed to allow for compressed air to be blown through the filters as a post filtration operation to force as much of the liquid out of the filter cake as possible.

We also take great care to make sure that no brass, bronze or galvanized parts are used on the machines in areas that may come in contact with the pregnant gold solution. Everything the slurry comes into contact with is suitable for the application.


Filter Press sizing Guidelines For Merrill Crowe


Typical design guidelines use a range of flows as the process requirements may vary dependent on ore type, plate style, precoat material (if used), particle size and cloth type. When a precoat is used, a pressure differential is maintained across the filtration area which keeps the material from falling to the bottom of the chamber. Therefore, a minimum flow rate through the press is required.

We design the filter plates, cloths and piping specifically for continuous high-velocity flow rates. With enlarged feed and discharge eyes as well as larger piping and manifolds, our presses will withstand increased pressures.

Note: The amount and grade of material required for pre-coat is dependent on the ore type and particle size of the precipitate. It is selected from site experience.

 Flow Rates For Precoat and Filter Slurry

​Minimum Precoat Flow Rate:
0.25-0.5 gpm/ft2
(~0.6-1.2 m3/hr/m2)
Initial Filter Slurry Flow Rate:
0.5-0.8 gpm/ft2
(~1.2-2 m3/hr/m2)