Disc Grinder

What is the Disc Grinder?

A disc grinder reduces brittle material between rotating grinding discs, giving a controlled and reproducible particle size. It is used for minerals, ores, ceramics and cement before chemical analysis as part of sample preparation.

Overview

A disc grinder presses material between two grinding discs, one or both of which rotate, so the sample is reduced by friction and compression as it moves outward. The gap between the discs sets the final particle size, which can be as fine as a few tens of micrometres. Discs are available in hardened steel, tungsten carbide, zirconia and agate to suit hardness and contamination requirements. The design is robust and produces a reproducible particle size that is valued for X-ray fluorescence and other analyses where the powder must be consistent. Feed rate and disc wear are the main factors affecting product quality.

How does it work?

Grinders reduce particle size by different mechanisms. Mortar grinders rub the sample between a pestle and a bowl, producing a fine product with little contamination when agate is used. Cutting grinders shear material between rotating blades and fixed counter knives, which suits fibrous, soft and elastic samples. Disc grinders press material between rotating discs and give a controlled particle size. Rotor beater grinders use rapidly moving beaters to shatter brittle and medium-hard material, and cryogenic grinders embrittle the sample with liquid nitrogen before impact so that heat-sensitive or sticky samples grind cleanly. Particle size, throughput and contamination depend on the mechanism, the tool material and the grinding time.

What are the key features?

• Rotating grinding discs for friction reduction
• Adjustable gap for controlled particle size
• Disc materials for different hardness and cleanliness
• Robust design for continuous use
• Reproducible powder for X-ray analysis

What are the technical specifications?

A typical disc grinder configuration offers final particle size of Down to 20 µm, max feed size of 15 mm, throughput of Up to 100 kg/h, disc diameter of 200 mm, disc material of Hardened steel, tungsten carbide or agate and gap adjustment of Micrometric. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Disc Grinder is used in X-ray fluorescence sample preparation, ore and mineral fine grinding, cement and ceramic analysis and slag and clinker preparation. Across the wider Grinders class, laboratories also deploy it for food and feed sample homogenisation, soil, sediment and rock preparation and plant and biomass material grinding.

Which standards and certifications apply?

Relevant standards and methods include ISO 3310-1, ASTM E11, ISO 2591-1, EPA 3050B and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Clean the grinding set thoroughly between samples to prevent cross-contamination, and pre-grind a portion of the sample or an inert material to condition the surfaces when trace work demands it. Do not overfill the grinding chamber, since excess sample reduces efficiency and raises temperature. Allow heat-sensitive samples to cool, or use cryogenic grinding, to avoid loss of volatiles and changes in composition. Inspect blades, discs and pestles for wear, and replace them on schedule to keep particle size reproducible. Follow the electrical safety requirements of IEC 61010-1 and, for cryogenic work, handle liquid nitrogen with appropriate ventilation and protection.

How do I select the right Disc Grinder?

Choose a disc grinder for brittle material where a reproducible, fine particle size is required for analysis. Confirm the achievable particle size meets the method and that the disc material suits the sample hardness and trace-element limits. In an RFQ state the sample type, feed size, target particle size, throughput and disc material.

How does it compare with other Grinders variants?

Choose a grinder according to the sample properties and the required final particle size. Hard, brittle material suits a disc or rotor grinder; fibrous, soft and elastic material suits a cutting grinder; and fine, homogeneous powder for trace analysis favours a mortar grinder with an agate set. Heat-sensitive, sticky or volatile samples suit cryogenic grinding with liquid nitrogen. Confirm the final particle size range, sample capacity and throughput, and that the grinding set material does not introduce the elements being analyzed. Consider cleaning between samples, noise and dust, and whether the method requires a defined particle size distribution.