One of the biggest issues in recycling systems occurs when utilizing a wet tank for density separation. Not only does the material you are processing get wet, but any contaminates on that material are transferred to the water, which makes it subject to EPA disposal regulations.
One way to avoid this is to use an air classification device such as the General Kinematics DE-STONER® . The DE-STONER® uses a high velocity, low pressure air stream to blow lighter density material through the machine while heavier material falls out the bottom of the device. By separating the material this way, lights and heavies can continue on for further processing without having to dry the material. Further, there is very little maintenance involved with the DE-STONER®… just an occasional cleaning and greasing of the low horsepower vibratory motor.