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Mortar Grinder RM 200 technology

Mortar grinders comminute, mix and triturate by pressure and friction. The function of the scraper is to feed the material into the area between the mortar and pestle. This forced feed ensures that the whole of the sample is continuously subjected to the grinding and trituration process and is also intensively mixed. The pestle is not located in the center of the mortar but is offset; contact with the rotating mortar and the sample causes it to rotate automatically. The necessary grinding pressure is achieved by the weight of the pestle itself combined with the adjustable spring pressure acting on its axis.

Selection of grinding sets
Mortar and pestle made of 7 different materials
The choice of the suitable grinding set material depends primarily on the hardness of the sample and the possible effects of any abrasion on the subsequent analysis or further processing. For example, the DAB (Deutsches Arzneimittel Buch – German Pharmacopoeia) stipulates the use of hard porcelain grinding sets for the preparation of pharmaceutical and homeopathic products. For soft to medium-hard or pasty substances grinding sets made from hard porcelain or sintered aluminum oxide (Al2O3) are usually adequate. For processing hard, abrasive substances, for long-term and for heavy-metal-free processing, we recommend the use of grinding sets made from agate, zirconium oxide or tungsten carbide. For less demanding applications, also under rough conditions, grinding sets made from chrome steel or stainless steel should be used. The standard scraper is made from abrasion-resistant Vulkollan. A special version made from beech wood is available as an option for use in the pharmaceutical sector. A PTFE scraper is particularly suitable for cryogenic grinding. The mortar of the RM 200 has a maximum useful volume of 190 ml
Tips for optimum results
• Samples that are difficult to grind can be cooled or processed by using grinding aids. • Moist soils and marine samples containing fats should be dried by treatment with Na2SO4 before grinding. • For the preparation of pastes the mortar containing the sample (e.g. cocoa nips) should first be heated to approx. 40 °C in a temperature cabinet. • The addition of Aerosil® helps to avoid caking when grinding pharmaceutical products. • Pure quartz sand can be added as a grinding aid when processing oil seeds (rape seed, soybean, mustard, etc.).

Agate hand mortars
Hand mortars made from agate are particularly suitable for grinding, mixing and triturating medium-hard to hard substances. Agate is extremely abrasion-resistant and very pure (99.9% SiO2). This guarantees its neutrality for the subsequent analysis. The quality of RETSCH hand mortars is particularly high. The abrasion surfaces are smooth and flawless, the outer surfaces are uniformly ground.