Introduction
The document provides technical details on drum mills used for fine and ultra-fine grinding of brittle materials. These mills operate discontinuously and are capable of both size reduction and homogenization of materials.

Application
Drum mills feature a horizontal grinding drum that rotates around a fixed center. The grinding media inside the drum pulverizes the material through pressure, impact, and shearing actions. Common grinding media include balls or Zylpebs, with steel rods used for specific applications. Key operating conditions include drum speed and filling conditions, typically between 70% to 80% of the critical speed. Energy-efficient comminution depends on the grinding media and filling extent, with standard figures being a 35% grinding-media filling and 25% material filling of the drum volume.

Function
Discontinuous drum mills are charged through an opening with a quick-locking device. For wet mills, a discharge grid with a shut-off valve is used for emptying, while dry mills discharge material through a grid fitted in place of the lid. A dust hood collects discharged material.

Technical Specifications
The drum mill is mounted on a stand via ball bearings and driven by a gear motor. Dry mills have a dust hood with flaps for accessibility, while wet mills have similar features for easy filling and emptying. Special executions include ceramic or rubber linings for metal-free crushing, double jackets for temperature control, and continuous versions with helical vanes for material feed and removal.

Technical Data
The document provides a table with specifications for different machine types, including volume, dimensions, RPM, grinding-media weight, and driving power. Variations in mill weight and dimensions depend on the version and lining thickness.

Nomenclature
The nomenclature section explains the coding system for drum mills, detailing the machine description, operation type, drum mill version, machine type, and operation mode.