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The DEROCKER is ideal for alluvial mining in areas with large boulders, and can easily handle light to moderate clay with an optional high-pressure spray system. It delivers a -2" product to downstream recovery and discharges clean washed +2" rock and boulder separately.

Key Features

  • Automatic, spring loaded feeder
  • Self-cleaning Grizzly Bars
  • All rocks washed thoroughly

The DEROCKER was developed in Canada’s historic Yukon Territory by a professional Placer Miner to overcome the problems of plugged grizzlies and effectively washing course rocks, boulders and gravel to liberate and retain the particles of gold.

The DEROCKER easily handles angular and slab shaped materials or boulders up to 4 feet in diameter. Unlike other systems, the greater the percentage of larger rocks and boulders, the greater yardage the DEROCKER will process.

As the subframe moves back and forth , the deck (grey chain) undulates, causing the material to move down the deck with the 2" minus dropping through the grizzly bars (not shown) and out the bottom to the gold recovery system, leaving the washed coarser material on the top of the deck to be discharged.

Specifications Model 8 x 20 Model 10 x 20 Model 14 x 20

Average Gravel Capacity

Cubic Yards/Hour 80 - 150 100 - 200 150 - 280
Tons per Hour (120 - 230) (150 - 300) (230 - 420)
Cubic Meters Per Hour ​60 - 120 ​75 - 150 ​120 - 220

Water Requirements*

1,000 - 1,800 GPM
3,800 - 6,800 Litres/Min

1,500 - 3,000 GPM
5,600 - 11,500 Litres/Min

2,100-4,000 GPM
8,000 - 15,400 Litres/Min

Operating Dimensions 8' 6" x 21'+ 10' 5" x 21'+

14' 5" x 21'+

Shipping Dimensions 8' 6" x 21'+ 10' 5" x 21'+

1 piece 10' 5" x 21'+
2 pieces 3' x 21'+

Weight 45,000 Lb 47, 500 Lb 54, 000 Lb
20,500 Kg 21, 500 Kg 24, 500 Kg


30 HP Electric 40 HP Electric 50 HP Electric

There are a variety of loading decks, spray systems and product sizing options available for the DEROCKER customized to your specific mining needs.

With the DEROCKER set on a eleven degree slope, the material to be processed is loaded into a surge pile in the upper end of the machine where a built-in Spring-Loaded Feeder evens the material flow across the deck while the loader cycles to the pit for more material.

The gold bearing boulders and gravels are moved across the self-cleaning grizzly bars in a wave action while being washed by high pressure from the water manifold. The coarse, rocky material is discarded from the lower end of the DEROCKER where it can be easily removed.

The 2" minus fines wash through the slots between the grizzly bars and are carried out the bottom to suitable gold recovery equipment (Centrifuges, Circular Jigs and Sluices, available from RMS) by the process water. The total water requirement of the system is relatively low as the sluice uses the same water that is used to wash the boulders.

The RMS-Ross Derocker in action
RMS-Ross Derocker with Articulating Deck
Close up of the RMS-Ross Derocker Spray System
Material being washed on the RMS-Ross Derocker Articulating Deck!
Custom Set up for mine sizing and screening circuit. Designed by RMS-Ross