Particle size analysis

This article describes the determination of the size of particulate solids, where the meaning of the particle excludes those of subatomic particles, which belong to the field of particle physics.

Particle size analysis, particle size measurement, or simply particle sizing is the collective name of the technical procedures, or laboratory techniques which determines the size range, and/or the average, or mean size of the particles in a powder or liquid sample.

Particle size analysis is part of Particle Science, and its determination is carried out generally in particle technology laboratories.

The particle size can have considerable importance in a number of industries including the chemical,food, mining, forestry, agriculture, nutrition, pharmaceutical, energy, and aggregate industries.

Chemical Industry

The Particle Technology Forum, an international and interdisciplinary forum, hosted by the American Institute of Chemical Engineers, defines: «...particle technology -- that branch of science and engineering dealing with the production, handling, modification, and use of a wide variety of particulate materials, both wet or dry, in sizes ranging from nanometers to centimeters... spans a range of industries to include chemical, petrochemical, agricultural, food, pharmaceuticals, mineral processing, advanced materials, energy, and the environment»

There are a large number of methods for the determination of particle size, and it is important to state at the outset, that these different methods are not expected to give identical results: the size of a particle depends on the method used for its measurement, and it is important to choose that method for its determination which is relevant to its use.

Mining

The size of materials being processed in an operation is very important. Having oversize material being conveyed will cause damage to equipment and slow down production. Particle-size analysis also helps the effectiveness of SAG Mills when crushing material.

Agriculture

The gradation of soils affects water and nutrient holding and drainage capabilities. For sand-based soils, particle size can be the dominant characteristic affecting soil performance.

Particle-size analysis in the agriculture industry is paramount because unwanted materials will contaminate products if they are not detected. By having an automated particle size analyzer, companies can closely monitor their processes.

Forestry

Wood particles used to make various types of products rely on particle-size analysis to maintain high quality standards. By doing so, companies reduce waste and become more productive.

Aggregate

Having properly sized particles allow aggregate companies to create long-lasting roads and other products.

Methods

A few examples, to be extended, and completed later are given here:

• sieving
• Sieve analysis
• Laser diffraction analysis
• sedimentation
• elutriation
• microscope counting
• using a Coulter counter
• Dynamic light scattering
• Imaging Particle Analysis
• Aerosol mass spectrometry

There are several companies that manufacture accurate instruments for determining particle size quickly and easily. These companies include Winner Instrument,Cilas, Brookhaven Instruments, Malvern Instruments, Microtrac and Horiba.