Meet Our Super Max!

Over the last 70 years, the Keene family has been the world leader in portable dredging and dry washing equipment. The first sump system and triple sluice was developed on an eight-inch submersible dredge built by Ernie Keene in the early 1950s. Ernie also built our now world-famous triple sluice dredge back in the early 1970’s. In the late 1980’s we introduced the three-stage sluice system, as well as many other innovative firsts.

In 2016 we developed the Supermax Sump Dredge. This beast outperforms all other dredges in the world for micro-fine gold recovery. The entire dredge was built with state-of-the-art technology including new floats, frame, pumps, power jets and more. The sluice box is oversized to control the material and allow the fine material as it is classified into a slower velocity zone. We have found through years of experience, testing, and customer feedback, that the best method to collect gold is to alter the sluice box into different riffle sizes and expanded metal classifiers. We have also found that the use of woven wire creates greater drag and deposits the smaller material much more effectively and efficiently than a traditional punch plate.  The large 8-foot by 24-inch wide sluice box will capture the majority of heavy material and disseminate the clay conglomerate.  The oversized box
provides a smooth slow slurry as it is classified into the sump, which is located at the end of the main sluice.


The sump was engineered by computer-aided design, optimizing the seamless flow of fine material that is being drawn into the sump and vacuumed out into the side boxes. One of the main keys to making the sump work correctly is to use the custom-made, heavy woven wire to create the proper drag on finer material which allows the coarser nonvalue material to pass through. The sump creates a slight negative vacuum on the screen that pulls 100% of all the finer values into the sump. From there it is pumped into the elevated side boxes. By pumping the minus 1/8th material into a controlled flow environment, all the super fine gold, up to 500 mesh, can be recovered from the side sluice boxes.

The Side boxes are constructed with a 10-inch wide header box that flares up 17 inches wide and is 5 feet in length.  The sluice is lined with our world-famous Miracle Mat and is partially covered with expanded metal.

As stated earlier, the new float and frame assembly is also newly designed. The frame is precision made on a C&C Mill and water jet machine and constructed out of lightweight tubular steel for superior strength.  The floats are by far the most advanced floats in the industry, providing a long tapered nose with cupped runners. This allows the dredge to cut through fast water effortlessly. Constructed of cross-link polyethylene material with brass inserts that are cast into the top of the floats for securing to the framework of the dredge. Did we mention that the universal frame sections make this dredge a snap to set up and disassemble?  You will need only a 9/16th wrench and socket to put this frame together.

Our standard Super Max model is powered by two GX390 engines; our PHP500 pumps provide superior performance at depths to 20 feet.  The pumps are equipped with a 1-inch accessory port that drives a pair of 2.5-inch suction systems.  The systems are outfitted with ball valves that are equipped to meter the flow to the side sluices with precision. You can use the side sluice as a primary clean-up concentrator. What does that mean? Well, traditionally you would have to haul several buckets of concentrates and process the material on a separate unit, which could take hours, depending on the concentrating equipment available.  With the Super Max, cleaning the concentrates is a breeze! Simply take the concentrates from the main sluice and run them through the side boxes. The result is at the end of the day you have a nominal amount of concentrate which completely reduces the need for secondary clean-up equipment.

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6220SMAX 6″ Super max Dredge by Keene Engineering

This is Keene Engineering’s Newest 6″ dredge that is designed for super fine gold recovery even down to 300 mesh. This new dredge has it all, portability, breaks down into small component, amazing fine gold recovery high power and more.

HOSE Jet Jet
6226SMAXDIA GX390 Honda PHP500 263 74” x 207” 35′ 3/4 gph 16 24”x 14’ 25’-SH6 PJ6T250 PPJF60 1400 1500
6226MAX GX390 Honda PHP500 263 74” x 159” 35′ 3/4 gph 16 24”x 8’ 25’-SH6 PJ6T250 PPJF60 1015 1065
6220SMAX GX390 Honda PHP500 263 74” x 159” 35′ 3/4 gph 16 24”x 10’ 25’-SH6 PJ6T250 PPJF60 1157 1207
6220SDMAX 10 hp Diesel PHP500 263 74” x 159” 35′ .50 gph 15 24”x 10’ 25’-SH6 PJ6T250 PPJF60 1245 1307
SM24K Conversion Kit

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Call us today and let us configure a package that is perfect for your needs!