The impurity laden particulate material to be cleaned by a gravity feed deduster is passed through a magnetic field of varying intensity to neutralize the static charge causing the impurities to adhere to the primary product. The material is then subjected to air flows to separate the neutralized debris from the primary product. The air flows can be of high velocity and can be either pressurized air or vacuum induced. The cleaned product is collected and the contaminated air is treated to recover the debris therefrom.