Comminution Flashcards
Particle size influences bioavailability - a smaller particle size results in faster dissolution. True or false?
True
What is meant by comminution?
The reduction of solid materials from a bigger mean particle size to a smaller mean particle size
The efficiency of a conventional ball mill is greater than that of a vibratory mill. True or false?
False - vibratory mill more efficient
Dry sieving is usually more efficient than wet sieving. True or false?
False - wet sieving is more efficient
Which milling method is defined as self-classifying?
Cutter mill
Separation efficiency is the effectiveness of a given process in separating particles into oversized and undersized fractions. True or false?
True
How many micrometres is a coarse powder?
> 350
How many micrometres is a medium/fine powder?
100-350
How many micrometres is a fine powder?
50-100
How many micrometres is a very fine powder?
10-50
How many micrometres is a micronised powder?
<10
The sieve method is simpler and more cost effective than microscopy. True or false?
True
The sieve method provides particle shape information. True or false?
False
Which particle size analysis method sorts a large quantity of particles into different size ranges and determines the particle size distribution based on the mass collected in each range?
Sieve method
Mohs’ scale is a quantitative measure of hardness. True or false?
False - qualitative
Brinell or vickers is a quantitative measure of hardness true or false?
True
Which milling method achieves a particles size of 1-300 micrometres?
Attrition
Which milling method achieves a particles size of 100-100,000 micrometres?
Cutting
What particle size can a ball mill achieve?
1-200 micrometres
Which milling method achieves a particles size of 20-100,00 mircometres?
End runner
Which milling method achieves a particle size of 1-1000 micrometres?
Vibration
Which milling method achieves a particle size of 600-200,000 micrometres?
Roller
What particle size can a fluid energy mill achieve?
1-100,000 micrometres
Which milling method achieves a particle size of 10-9,000 micrometres?
Pin mill
