Ball mill for malleable material recovery

A method of recovering lead of firearm projectiles from a material, the method comprising:

• providing a ball screen;
• placing the material within the ball screen, the ball screen comprising a sleeve having a plurality of apertures, a material entrance end at one end of the sleeve, a closed material exit end at an opposite end of the sleeve, and a plurality of balls within an interior of the sleeve, the closed material exit end comprising at least one discharge opening that can be opened or closed, the material comprising firearm projectiles containing the lead, which are malleable and have a size that is larger than the plurality of apertures;
• rotating the ball screen with the at least one discharge opening being closed to crush portions of the material to a size that allows the crushed material to pass through the plurality of apertures, and to cause the plurality of balls to press the lead of the firearm projectiles such that the lead remains larger than the plurality of apertures and remain within the interior of the sleeve;
• forcing air through the interior of the ball screen during the act of rotating the ball screen in order to blow at least some of the material within the ball screen that is lighter than other material within the ball screen out an opening in the ball screen when crushing portions of the material;
• and
• discharging the lead remaining in the ball screen from the ball screen by opening the at least one discharge opening while further rotating the ball screen, the at least one discharge opening being larger than each of the plurality of apertures and smaller than a smallest one of the plurality of balls, to permit the lead that is larger than the apertures and smaller than the smallest of the plurality of balls, after performing the act of rotating, to fall through the at least one discharge opening while retaining the plurality of balls within the rotatable ball screen.