RETSCH DM 200 Disc Mill

RETSCH DM 200 Disc Mill — Accurate, Fast, and Consistent Sample Grinding

The RETSCH DM 200 Disc Mill is a tough and robust mill that can withstand rough conditions in laboratories, pilot plants and even online quality control of raw materials. With its sturdy design, it delivers the desired grind in just a few minutes.

Working on a unique principle of operation, the DM 200 has a dustproof chamber where the feed material is introduced through a filling hopper. The material is then centrally fed into the grinding zone between two vertical grinding discs. One disc is fixed and the other rotates, drawing in the feed material. The pressure and frictional forces generated by the grinding discs and plates produce the comminution effects and size reduction. The progressing arrangement of the grinding disc meshing allows for preliminary crushing, followed by fine grinding as the sample moves to the outer regions of the grinding discs. The processed sample is collected in a receiver after exiting through the grinding gap. The gap width between the grinding discs is adjustable from 0.1 to 5 mm and can be adjusted during operation. The plates are reversible and essential for grinding. A observation window is also provided for easy gap setting verification.

The DM 200 is versatile and can be used for brittle and medium hard materials, grains, corn, wheat, minerals, stone, fibrous materials. It can also process materials like bauxite, cement clinker, chalk, chamotte, coal, coke, concrete, construction waste, dental ceramics, dried soil samples, drilling cores, electrotechnical porcelain, ferro alloys, glass, granite, gypsum, hydroxyapatite, ores, quartz, sewage sludge, sintered ceramics, slag, soils, steatite and more. The grinding discs and other parts are made of durable metals for longevity and precision.The DM 200 has several advantages that make it a reliable and efficient solution. Analytical fineness can be achieved for sample preparation and the mill allows to adjust grinding parameters to optimize results. It has good crushing performance and reproducible results due to gap setting. The grinding chamber is hinged for easy and grinding discs have long working life. Also contamination free grinding is possible with a wide range of materials. It can be connected to a dust extraction system for a cleaner working environment. Additionally the DM 200 can be operated together with the Jaw Crusher BB 200 or other crushers such as the Portable Hammermill Crusher for higher productivity.

With its features and capabilities the RETSCH Disc Mill DM 200 is the perfect choice for precise grind sizes in harsh conditions. The DM 200 is suitable for coarse and fine grinding but not for very wet materials. It can be used as a grinder for many applications.

Thanks to its sturdy design the RETSCH DISC Mill DM 200 can be used in laboratories and pilot plants as well as online for quality control of materials. For those seeking a versatile cutting solution in similar environments, the RETSCH SM 200 Cutting Mill is also a powerful option. The powerful DM 200 delivers the desired grind in just a few minutes.

Disc Mills

Disc mills are advanced grinding devices for the fine grinding of a wide range of materials, including friable materials that require careful sample preparation for spectral analysis and quality control. The first disc mill, the Bertram disc mill, was developed to meet the growing demand for efficient processing of materials and to achieve a uniform particle size distribution. Over time disc mills have become essential in industries like ceramics and pharmaceuticals where precise control over particle size is crucial for product quality. These work by using centrifugal force to grind materials between two stationary discs—usually made of hardened steel or tungsten carbide—ensuring consistent and reproducible results. Therefore disc mills play a key role in sample preparation for further analysis and high standards in quality processes.

Function Principle of Disc Mills

In the DM 200 the feed material enters the dustproof chamber from the filling hopper and is fed centrally between two vertical grinding discs. A moving grinding disc rotates against a fixed one and draws in the feed material. The necessary comminution effects are generated by pressure and friction as primary forces responsible for grinding. The progressively arranged grinding disc meshing first subjects the sample to preliminary crushing; centrifugal force then moves it to the outer regions of the grinding discs where fine comminution takes place. The processed sample exits through the grinding gap and is collected in a receiver. The gap width between the grinding discs is adjustable and can be adjusted during operation in the range between 0.1 and 5 mm; an additional observation window is provided for checking the gap setting.

Technical Data

Disc mills are designed to accommodate various sample types and grinding requirements. Most models have two stationary discs, one disc driven by a worm gear and the other fixed. The grinding zone between the discs is where the material is ground and the gap between the discs can be adjusted to the final particle size. To improve grinding efficiency the discs can be made of zirconium oxide and have special groove patterns. Some disc mills have axial movement for processing different sample types and to improve overall grinding performance. Key technical data are the diameter of the discs, the rotational speed and the grinding capacity all contributing to the mill’s ability to deliver consistent results across many applications.

Applications in Sample Preparation

bauxit, cement clinker, chalk, chamotte, coal, coke, concrete, construction waste, dental ceramics, dried soil samples, drilling cores, electrotechnical porcelain, ferro alloys, glass, granite, gypsum, grains, corn, wheat, minerals, stone, fibrous materials, hydroxyapatite, ores, quartz, sewage sludge, sintered ceramics, slag, soils, steatite, …

Safety

Safety is top priority in the design of disc mills to ensure operator safety and reliable operation. Modern disc mills have many safety features: emergency stop buttons for immediate shutdown, protective guards to prevent accidental contact with grinding zone, sensors for blockages or malfunctions. Disc mills are designed for easy cleaning and maintenance with accessible grinding zone to prevent contamination and to maintain optimal performance. Follow the recommended cleaning procedures and maintenance schedule to enhance safety and to prolong the life of the equipment. Operators should follow the manufacturer’s guidelines and use personal protective equipment like gloves and safety glasses when handling and operating disc mills.

Handling and Operation

Proper handling and operation of disc mills is crucial to achieve the desired particle size and to process the sample efficiently. Before use read the user manual to familiarize yourself with the mill’s controls and settings. Place it on a stable, level surface and feed the material into the grinding chamber in a controlled way to avoid overloading. Adjust the speed and the gap between the discs to achieve the required particle size distribution for the different samples. Monitor during operation to adjust in time to avoid overheating or blockages. During business hours have trained personnel available to answer operational questions or concerns to ensure smooth and safe operation of the disc mill.

Maintenance and Repair

Regular maintenance and timely repair is essential to maintain the performance and life of disc mills. Regular inspection and replacement of grinding discs ensures consistent grinding quality, thorough cleaning after each use prevents cross contamination between samples. Lubricate the worm gear and other moving parts according to the manufacturer’s recommendations to minimize wear and extend service life. In case of a malfunction repair as soon as possible by qualified technicians to minimize downtime. Keep a spare set of grinding discs and other wear parts on hand for uninterrupted operation. By following the maintenance schedule and addressing issues as they arise you can rely on your disc mill to deliver high quality grinding results for years to come.

Product Advantages for Product Quality

• good crushing performance

• reproducible results due to gap setting

• hinged grinding chamber for easy usage

• grinding discs with long working life

• wide range of materials for contamination free grinding

• connector for dust extraction

• can be operated together with Jaw Crusher BB 200