A stirred ball mill may include a milling jar, at least three agitator shafts, and a drive. The milling jar may be arranged in a main direction and may have a milling chamber that is adapted to receive milling material and milling aid elements. Each of the at least three agitator shafts has a center axis that is arranged parallel to the main direction of the milling jar and is configured as a screw that is mounted fixedly to a frame in the milling jar such that each agitator shaft is rotatable about its center axis. The drive is configured to rotate the agitator shafts about their respective center axes without any contact between the agitator shafts. The center axes of the agitator shafts may be arranged as side edges of a prism.

An agitator mill having a circular-cylindrical outer stator and an agitator having a circular-cylindrical rotor. The rotor is arranged within the outer stator, and a milling chamber between the rotor and the outer stator. In the milling chamber, a through-flow direction which extends from a feed channel to a discharge channel. Several rotor milling tools are attached to the rotor, wherein several outer-stator milling tools are attached to the outer stator. The outer-stator milling tools are arranged adjacent to and in the circumferential direction and form rows. These rows are arranged parallel to one another on the outer stator. On the side, facing away from the feed channel the outer-stator milling tools of at least one row have a greater radial length than the other outer-stator milling tools. The outer-stator milling tools of each row in the circumferential direction each have the same length.

Attrition mills and propeller shaft assemblies therefor are described having features for enhanced installation and maintenance. Some embodiments include propellers having enhanced material processing characteristics.

A process for separating a solid having two or more components, at least one of which is lyophobic and at least one of which is lyophilic. The process comprises, in a single step, comminuting a mixture of the solid in a first liquid to which one of the components is lyophilic and to which the other component is lyophobic and in a second liquid which is immiscible with the first liquid and which will wet the lyophobic component to form agglomerates or floes of the lyophobic component and the second liquid in a mill having positive transport capability such that the mill causes the mixture to be transported therethrough. The second liquid comprises a bio-oil, bio-diesel or combination thereof. The agglomerates are then separated from the mixture. This process may be used for beneficiating a coal containing ash.

A process for comminuting particles of heterogeneous material. The particles of heterogeneous material are fragmented and broken into smaller particle size by breaking them against each other. Heterogeneous material means two or more different solid materials or phases in the same solid. The component materials may have different specific gravity and/or hardness. In the process, a slurry of particles of heterogeneous material is pumped through an agitated mixture of impingement media, wherein the impingement media has a size greater than a size of the particles, wherein adjacent impingement media interact to create impingement zones through which the particles pass and impinge each other to cause the particles to fracture and break into smaller particles. The impingement media may be from 5 to 10 times larger than the particles. The impingement media may be harder than the particles. The heterogeneous material may be coal.

A stirring mill, including a horizontally arranged milling vessel and a stirring shaft which is arranged therein so that it can be rotationally driven are provided. The stirring shaft has a first stirring shaft section adjacent to an inlet for material to be ground, which has a smaller diameter D24, and a second stirring shaft section adjacent to an outlet for material to be ground, which has a larger diameter D25 and in which a separating device is formed. Bypass channels leading into the separating device are formed in the first stirring shaft section.

A process for comminuting particles of heterogeneous material. The particles of heterogeneous material are fragmented and broken into smaller particle size by breaking them against each other. Heterogeneous material means two or more different solid materials or phases in the same solid. The component materials may have different specific gravity and/or hardness. In the process, a slurry of particles of heterogeneous material is pumped through an agitated mixture of impingement media, wherein the impingement media has a size greater than a size of the particles, wherein adjacent impingement media interact to create impingement zones through which the particles pass and impinge each other to cause the particles to fracture and break into smaller particles. The impingement media may be from 5 to 10 times larger than the particles. The impingement media may be harder than the particles. The heterogeneous material may be coal.

The invention relates to a circular disc element (10) comprising at least two beam elements (20). Each beam element extends beyond an outer circumference (11) of the circular disc element (10) in an extension direction (100) which is parallel to a radial direction (101) of the disc element (101). The circular disc element (10) further comprises at least two holes (30) extending through the circular disc element (10) in a longitudinal direction (110) which is substantially perpendicular to each of the extension directions (100) of the at least two beam elements (20). The at least two 10beam elements (20) are equidistantly spaced apart from each other with respect to a circumferential direction (120) of the circular disc element (10), which circumferential direction (120) corresponds to the outer circumference (11) of the circular disc element (10). The invention further relates to a use of the circular disc element (10) as grinding means in a grinding process, to a device for grinding slurry (50) as well as to a method for grinding slurry (50).

Attrition mills and propeller shaft assemblies therefor are described having features for enhanced installation and maintenance. Some embodiments include propellers having enhanced material processing characteristics.

A stirrer mill for the treatment of flowable grinding stock. The stirrer mill includes a milling container, a milling chamber delimited by the container wall, and a stirring mechanism having a rotor which rotates about a central longitudinal axis and has an inside diameter (d351). Tools, which extend toward the container wall, are attached to the rotor. The stirrer mill also includes an internal stator arranged inside the rotor. A grinding stock discharge channel is formed, between the rotor and the internal stator, through which the grinding stock passes to a separating device and, thereafter, to a discharge line. The milling chamber is at least partially filled with grinding bodies having a diameter (c). Above the internal stator is arranged a separating device with a diameter (d30). The distance (s) between the rotor and the grinding body separating device is given by the relationship: s=0.5.Math.(d351d30)5.Math.c.