Abstract: A fluid-energy mill for size reduction of a material includes a manifold defining a grinding chamber having a first radius extending from a center of the grinding chamber, a gas inlet, a feed inlet, and an outlet. The feed inlet is positioned such that the material enters the grinding chamber tangent to a second radius extending from the center and larger than the first radius. The fluid-energy mill includes a cover for enclosing the grinding chamber. The manifold defines a non-circular groove around the grinding chamber, and a seal is positioned within the groove. The grinding chamber is cycloid-shaped. The manifold defines a protective pocket and a barrier at a region where the material enters the grinding chamber. The feed inlet includes a feed gas inlet, a material funnel, and a venturi. An intersection of the feed gas inlet and the material funnel form an elliptical hole. The feed inlet is oriented at an angle of about 30 degrees or more to a horizontal.

Abstract: A powderizing assembly includes a product line for receiving product sized powderized material from a powderizing mill, and a purger assembly for receiving non-product sized material from the mill. Non-product sized material is periodically removed from the mill and fed to the purger. The purger assembly includes a purge line in parallel with the product line for receiving material from the mill. The purge line includes a cyclone separator and a filter. A first valve is operable to direct material from the mill to one of the product line or the purge line. The first valve and a second valve are operable to isolate the product line from the purge line.

Abstract: A whirlwind updraft separator is converted to a side draft classifier by exchanging the rotor assembly for a rejector cage, removing the inner drum, opening the outer casing to provide for a side draft air inlet system, mounting a stationary fines chamber between the rejector cage and sealing the space beneath the side draft air inlet system to the top of the tailings cone.

Abstract: A particle classifier includes a generally cylindrical, air and fine particle permeable cage having a closed top and open bottom mounted to a central drive shaft. A casing surrounds the cage and defines a volute air passage about the cage with an air separation zone between the volute and the cage. A generally tangential air inlet is provided in the casing volute and a material inlet is provided in the upper end of the casing. A stationary chamber is positioned below the cage for the air and fine material which enter the cage. From the chamber, the air and fine material is directed to cyclone separators in which the air is separated from the particles. A hopper is positioned below the chamber for collecting coarser material which fails to enter the cage. The size of the volute can be adjusted by a vertical partition within the casing. The partition allows flexibility in setting the air velocity.