Content Handbook F

Outline of method

Sieve analysis consists of the quantitative separation of a powder into fractions with different ranges of particle size by use of an appropriate sieve or sieves. Sieving is carried out either (i) dry, by a process of shaking, tapping and brushing; or (ii) wet, by washing the material on the sieve with a stream of water. Treatment of the sample with a wetting agent is used, where necessary, to assist the sieving process. The specification or the method of analysis for the material under test gives directions as to whether dry or wet sieving is to be applied. Where more than one nominal aperture size is specified, the sample is first sieved on the smallest aperture sieve. This removes most of the very fine particles which tend to clog the sieves and may interfere with quantitative separation of the larger particles. The sieves are stacked in order of aperture size with the largest at the top; the retained material is transferred to the largest aperture sieve, and sieving continued until passage of undersize material through each sieve is substantially complete. The residue on each sieve is finally transferred to a dish, dried if wet sieving has been used, and weighed.

59.4 Sieve test for granular materials

The sample is sieved to obtain the amount of dust contained and the dust is then sieved for 5 minutes to determine the size distribution.

Scope

59.4 Sieve test for granular materials

This method is suitable for granular products, i.e. those materials of particle size between 250 ìm and 4 mm, and determines first the dust content and then the size distribution of the granular material (Note 5). The sieving is not rigorous but
determines the size distribution with sufficient precision for the purposes of application.