Vibratory Disc Mill

What is the Vibratory Disc Mill?

A vibratory disc mill grinds a few hundred grams of crushed mineral to below 75 µm in one to three minutes using a vibrating ring and puck in a sealed bowl. It is the standard workhorse for assay sample preparation.

Overview

The bowl is clamped in a cradle that oscillates at about 900 to 1500 cycles per minute. A ring and a puck inside the bowl are thrown against the sample and the bowl wall, grinding by impact and friction. Charging 100 to 400 g of material below 2 mm gives a product that usually passes 75 µm in one to three minutes, with reproducibility good enough for sequential assay work. Bowls come in tungsten carbide, hardened steel, zirconia and agate with volumes from 100 mL to about 2 L, and the sealed lid keeps dust in and limits moisture change. The main operating rules are consistent charge mass, a validated grinding time and quick cleaning between samples. Prolonged grinding heats the bowl, so timing is a compromise between fineness and sample temperature.

How does it work?

Pulverizing reduces particle size by impact, friction and attrition inside a closed vessel, and the energy supplied per unit mass determines the final fineness. In a planetary ball mill the bowl rotates around the sun wheel while turning on its own axis, so grinding balls fall and roll at high energy, giving very fine products in minutes. A vibratory disc mill shakes a ring and puck inside a bowl, producing fast, reproducible grinding of a few hundred grams. A Bond ball mill, with a fixed drum, ball charge and revolution count, is used to measure ore grindability rather than to prepare routine samples. Mortar grinders press and rub material between a pestle and a mortar under spring load, which suits soft to medium-hard minerals and minimizes fines. Jet mills accelerate particles in a gas stream so they break by particle-to-particle collision without media contact, protecting high-purity samples.

What are the key features?

• Oscillating cradle at 900 to 1500 cycles per minute
• Ring and puck grinding inside a sealed bowl
• Bowl volumes from 100 mL to 2 L
• Product below 75 µm in one to three minutes
• Timer with reproducible grinding duration
• Up to three bowls on some models for higher throughput

What are the technical specifications?

A typical vibratory disc mill configuration offers bowl volume of 100–2000 mL, maximum feed size of ≤ 2–5 mm, final fineness of < 75 µm, down to 40 µm, sample charge of 100–400 g, oscillation rate of 900–1500 cycles/min and grinding time of 1–3 min, timer controlled. 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 Vibratory Disc Mill is used in assay sample grinding below 75 µm, preparation for XRF pressed pellets, grinding of ores, slags and concentrates and cement and industrial mineral sample preparation. Across the wider Pulverizers class, laboratories also deploy it for grinding ore to assay fineness, preparation for X-ray fluorescence and diffraction and grindability testing for mill design.

Which standards and certifications apply?

Relevant standards and methods include ASTM E877, ISO 3082, ISO 12743, ISO 13320, GB/T 2007 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.

Fill the bowl to the recommended fraction of its volume, because too little material wastes energy and too much prevents media movement. Grind for the validated time rather than by eye, and check fineness by sieving a retained portion, since a mill that is wearing out takes longer to reach specification. Limit grinding to avoid heating the sample, especially for sulfide ores that oxidize and for materials whose moisture will be measured later. Clean bowls, rings and balls between samples with brushes, alcohol and, where needed, a purge charge of quartz or barren rock, and keep a log of bowl identity so contamination problems can be traced. Verify performance periodically with a reference material of known particle size distribution, and replace worn media before the product size drifts.

How do I select the right Vibratory Disc Mill?

Select the disc mill for routine ore grinding where a few hundred grams must reach 75 µm quickly and reproducibly. Choose bowl material by contamination tolerance, and specify bowl count, timer range and cleaning access for fast turnover between samples.

How does it compare with other Pulverizers variants?

Decide first how fine the sample must be and how many grams are needed at that fineness, then choose the mill that reaches it in a practical time. Planetary ball mills and vibratory disc mills cover the widest range and are the usual choice for assay samples. Mortar grinders suit smaller, softer samples and can be automated for repetitive work. Jet mills are reserved for high-purity or heat-sensitive materials because they need a compressed gas supply and have limited throughput. Grinding set material is as important as the mill itself: agate, zirconia and tungsten carbide minimize contamination of iron, chromium and other trace elements, while hardened or chrome steel is cheaper and more durable but contributes wear metals. Also consider how the mill handles sample mass, cleaning between samples, bowl sealing and the risk of over-grinding, which broadens the size distribution and can alter mineral phases.