Retsch XRD ball mill McCrone
The mill presented here was specially developed for sample preparation in the context of X-ray diffractometry. Thanks to the unique friction principle, its 48 cylindrical grinding media work particularly gently and deliver an extremely narrow particle size distribution. This represents a considerable advantage over other comminution methods, as the crystalline structure of the material is largely retained. It is therefore a popular choice for users in geology, chemistry and mineralogy. Similar mills such as the Retsch Planetary Ball Mill PM 400 also offer flexible application options, but differ in terms of design and grinding principle.
Powerful sample preparation for precise analyses
This ball mill has a compact design and can be easily placed on a laboratory bench. In addition to the gentle grinding process, it impresses with a very short grinding time of less than 30 minutes and low material abrasion. Its polypropylene grinding bowl has a screw-on, self-sealing cap and holds 125 ml of sample material. The scope of delivery includes different variants that either only include the beaker or a complete grinding set with matching grinding media.
Similarly equipped products such as the [Retsch CryoMill] focus more on cooling applications, while the present model is primarily aimed at the gentlest possible process control and preservation of the crystal structure. The XRD-oriented design allows both wet and dry grinding of various samples, from building materials to metals and ceramics. Thanks to the scalar adjustable speed (four levels between 1,000 and 1,500 min-¹), the process can be precisely adapted to the respective material hardness and brittleness.
■ Important technical features (selection):
- Areas of application: Crushing, mixing, grinding - dry & wet
- Typical grain size: <0.5 mm (feed), final fineness <1 µm
- Speed: 1,000-1,500 min-¹ (adjustable in four stages)
- Grinding bowl size: 125 ml made of PP (PE screw cap)
- Grinding time: 3-30 minutes (adjustable up to 99:59:50)
- Number of grinding positions: 1
- Standards: CE
Also worth mentioning is the robust DC drive concept, which ensures low-maintenance continuous operation. The compact design with a footprint of just 205 x 155 x 520 mm and a weight of around 19 kg ensures that it can be easily integrated into any standard laboratory.
Concrete fields of application and special features
The device is ideal for quality control, R & D and routine tests in research institutes or industrial laboratories. Due to its fineness and reproducibility, it is primarily used for the following materials:
- Building materials such as cement and slate to precisely test the composition of aggregates
- Mineral samples (mica, borides, carbides), where the exact characterization of the crystal structure is crucial
- Glass and ceramics to analyze the properties and purity of new materials
- Biological materials such as plant parts or bones, where gentle grinding without structural damage is key
Wet grinding is useful if the sample is temperature-sensitive or tends to stick when ground dry. Sensitive materials, where fine-rod abrasion by the grinding media would otherwise cause critical contamination, also benefit from the gentle grinding process of this mill.
FAQs
What is the maximum feed size of the sample?
The particle size should be less than 0.5 mm for optimum results. Coarser particles can be crushed in a pre-crusher beforehand.
Is cleaning time-consuming?
No, all relevant parts can be dismantled quickly. The smooth surfaces of the PP grinding bowl and the PE screw-on lid allow for quick cleaning.
Which materials are available for the grinding media?
Grinding media made of agate, zirconium oxide or corundum can be used, depending on the sample and desired purity.
Can samples be cryogenically ground?
Cryogenic applications are not envisaged, as this model is mainly geared towards room temperature processes.
Can the grinding time be set individually?
Yes, digitally you can choose from a range of a few seconds to almost 100 hours. However, 3-30 minutes is sufficient for most samples.
Summary
The ball mill described here combines gentle comminution, low sample contamination and a highly reproducible particle size distribution in a compact benchtop device. This is made possible by the special grinding method with 48 cylindrical grinding media, which gently grind material into the lower µm range while largely preserving its crystalline structure. Both wet and dry grinding can be carried out without any problems, providing laboratories in the fields of geology, chemistry and materials science with a versatile solution for precise sample preparation. With quick cleaning, minimal maintenance requirements and CE compliance, it is a reliable tool for users who rely on accurate analysis results.
