In some cases it can be useful to make sieve fractions before continuing one of the following treatments. Use sieves of e.g. 32, 63, 125 and 250 µ, and further treatment of the fractionated sample remains the same.
A laboratory coat must be used. The air extractor in the workshop is activated. Check if the sieve material is clean.
EQUIPMENT
- Sieves, 32, 63, 125 and 250 m
- Various stainless steel bowls
METHOD
Start with the coarsest sieve, and place it upon a collecting container. Then apply the sample and sieve it by making turning movements. The material smaller than the sieve can be sifted again with a smaller, finer sieve. In this way different fractions will be collected.
Write down the fraction size on the containers.
With a large sample a sieving machine can be of help.
CLEANING
The sieves must be shaken in the ultrasonic cleaner during 1 hour and subsequently rinsed and dried at 110ºC.