Dewatering Screen

Considering the importance of recovering fine particles such as wind-blown sand in wet mineral processing operations, processing plants have always aimed to achieve this goal. However, the high costs associated with supplying certain earlier washing equipment, as well as the need for medium-scale production rather than highly competitive, high-capacity output, have made this objective challenging for mine owners. Therefore, Asia Masheh Saz Company has developed a dewatering screen to make optimal use of existing washing equipment such as spiral sand washers, and to enable the recovery of fine particles (wind-blown sand) at medium production rates.

This machine operates in a manner fully similar to a dewatering washing screen, with the difference that the washing of 0–6 mm sand and larger sizes is performed by a spiral sand washer. In the pre-washing stage, 0–6 mm materials together with fine particles (wind-blown sand) are mixed with water by a spiral sand washer operating at a low angle and high speed. The output is then discharged onto a vibrating dewatering screen.

In the next stage, the dewatering screen removes water from the material through vibration and conveys the slurry, containing fines, clay, and silt, to the machine’s discharge chute.

In the discharge stage, the slurry from both the spiral sand washer and the chute—containing fine particles (wind-blown sand), clay, and silt—is transferred by a slurry pump to the inlet of a hydrocyclone. Inside the hydrocyclone, due to a dual vortex flow, fine particles (wind-blown sand) are separated from clay and silt and discharged from the bottom of the hydrocyclone onto the vibrating dewatering screen. The fine particles from the hydrocyclone, together with the previously washed 0–6 mm material, pass along the 3.6-meter vibrating screen deck and exit the machine as the final product.

It should be noted that the capacity of this system, depending on the feed supplied by the spiral sand washer, exceeds 120 tons per hour, and the required water consumption is approximately 3 to 4 inches.