Mortar Grinder

What is the Mortar Grinder?

A mortar grinder reproduces hand grinding mechanically, using a pestle against a bowl to produce a fine, homogeneous powder. With an agate set it is used for clean, fine grinding before trace analysis.

Overview

A mortar grinder uses a motorised pestle that rolls and presses against a rotating or stationary bowl, mimicking the action of hand grinding. The adjustable pestle pressure and scraper keep the sample in the grinding zone, so the whole batch is reduced evenly. Grinding sets are available in agate, hard porcelain, zirconia and stainless steel; agate is preferred for trace analysis because it adds almost no contamination. The machine produces a fine product, often below a few tens of micrometres after extended grinding, and handles both dry and wet grinding. It suits moderate sample masses and materials that must be ground gently.

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?

• Motorised pestle with adjustable pressure
• Scraper keeps sample in the grinding zone
• Interchangeable agate, zirconia or steel sets
• Dry and wet grinding capability
• Fine homogeneous product for analysis

What are the technical specifications?

A typical mortar grinder configuration offers grinding set of Agate, 100–200 mL, final particle size of Below 10 µm with extended grinding, sample capacity of Up to 200 g, pestle pressure of Adjustable spring load, bowl speed of About 100 rpm and grinding mode of Dry or wet. 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 Mortar Grinder is used in trace-element sample preparation, mineral and rock fine grinding, food and plant material grinding and pharmaceutical powder 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 Mortar Grinder?

Choose a mortar grinder for fine, homogeneous and low-contamination grinding of moderate samples. Confirm the grinding set material suits the analytes and the required cleanliness, and that the achievable particle size meets the method. In an RFQ state the sample type, mass, target particle size and grinding set 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.