Prom. devices of the "Deroker" type GGM-3, GGM-5 (PPM-5)

The device of the "Derocker" type (Derocker from Rock – stone) was developed in Canada for washing boulders. The prerequisite for the creation was the need to ensure productive loading of the rock with any available equipment: an excavator, a bulldozer, a loader, a dump truck, without paying attention to massive boulders that could disable flushing devices. The new design was based on a roar that withstands the impacts of boulders weighing more than a ton.
For the first time in the USSR, devices of the "Deroker" type began to be produced in the workshops of the Magadan Mechanical Plant. Products under the brands Hydro-mechanized screen with a width of 3 m GGM-3 and GGM-5 with a screen width of 5 m (later an upgraded version of this device was called PPM-5), are produced at the factory and currently. The supply of spare parts for the GGM-3 and GGM-5 devices was successfully mastered and produced by the Orotukan Mining Equipment Plant.

The principle of operation:
The screen consists of steel plates about 3 m – 5 m long, 20.4 cm wide and 25 mm thick, connected by hinges, the screen cloth is flexible. The screen cloth lies on a wheeled cart with car wheels and tires. The cart rolls along the canvas of the rumble, as on the road, only not from above, but from below. The flexibility and strength of the web, combined with the elasticity of the wheels, allow the screen to withstand a huge impact load.The trolley with wheels under the screen is constantly moving under the action of a hydraulic drive connected by flexible hoses to an electric oil station. The direction of movement of the trolley (forward-backward) changes automatically. During reciprocating movements of the trolley, "surface waves" are formed on the surface of the screen. Due to the undulating movements of the surface and the inclination of the screen, the material moves along it to the dump.There are gaps between the screen plates, depending on the washed fraction, it can be 30 or 50 mm (on request). The irrigation system located above the screen washes the rock under high pressure through the sprinkler, while the fine fraction falls into the cracks of the screen into a special tray, and the stones go into the pebble dump.The sublattice material from the tray flows by gravity for enrichment. The enrichment system may consist of a single gateway or a system of deep and shallow filling locks. The design of the gateways is set when ordering the device.
The scope of delivery of the drilling rig BU-20-2USH includes: a drilling rig assembly with an electric motor and a mast, a set of keys for maintenance, a guide device. The instrument is supplied by nomenclature and quantity in agreement with the customer.
Advantages:
On placers with well-washed bouldery sands, GGM (PPM) devices provide 2-3 times greater productivity, consume less water (respectively, electricity and diesel fuel), operate in automatic mode (no monitor is needed), are easy to maintain, are easily rearranged from place to place (usually installed directly in the bottom of the landfill or on the overburden dump)
Main disadvantages:
They are not effective enough when washing hard-to-wash clay sands and rocks with a large amount of flagstone, which falls into the cracks of the screen and can clog the sluices, while large flagstone on the screen may not be washed on one side, which increases gold losses.
The company LLC "OrMag" has extensive experience in the production and supply of canvases for devices GGM-3, GGM-5, with different widths of the sowing surface of the canvas, it is possible to supply both the canvas assembled and separately plates. Also, upon prior request, it is possible to manufacture trolleys, supply trolley wheels, and other parts of the device.
For the first time in the USSR, devices of the "Deroker" type began to be produced in the workshops of the Magadan Mechanical Plant. Products under the brands Hydro-mechanized screen with a width of 3 m GGM-3 and GGM-5 with a screen width of 5 m (later an upgraded version of this device was called PPM-5), are produced at the factory and currently. The supply of spare parts for the GGM-3 and GGM-5 devices was successfully mastered and produced by the Orotukan Mining Equipment Plant.