Sieving & Classifying

Remember playing hours and hours with the sand on the beach? One of your favorite tasks was sifting sand. Why?

Because you wanted to free the fine sand from gravel and stones. However, sometimes wet sand stuck to the stones.

This effect is typical when sifting solids also on an industrial level.
Smaller solid particles may be contained in the larger fraction due to adhesion effects.

How can the feedstock be separated?

𝐂𝐥𝐚𝐬𝐬𝐢𝐟𝐢𝐜𝐚𝐭𝐢𝐨𝐧 is the key word.

🔺 It evens out differences between particle sizes to ensure homogenous mixing.

🔺 Powdered material is classified through to deliver the desired particle size specifications.

For this purpose, appropriate sieve trays are used, which differ in mesh size and shape. Everything that falls through the openings in the sieve tray is called 𝐟𝐢𝐧𝐞 𝐦𝐚𝐭𝐞𝐫𝐢𝐚𝐥. What remains in the sieve is called 𝐜𝐨𝐚𝐫𝐬𝐞 𝐦𝐚𝐭𝐞𝐫𝐢𝐚𝐥.

Classification technology you may apply:

✅ Stream classification
Air classifying - Here the principle of gravity or centrifugal force is used for separation. Fine and thus light particles follow the air flow and the coarse and heavy particles follow the gravitational or centrifugal force.

✅ Float/sink method
when the separation medium is a liquid, the substance with the higher density then sinks to the bottom and the substance with the lower density floats to the surface.

Depending on the particle size required different mills & sieves apply.

👉 If you search for any of them you could

1. Check technology process availability on the #ProcessOnDemand portal
2. Or write us a message to check, how we could help you with your material


What are the real challenges in the classification process in your opinion?

What material have you sieved recently?

Next week topic: Sieve & Cleaning Balls