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Flashcards in Comminution Deck (25):
1

Particle size influences bioavailability - a smaller particle size results in faster dissolution. True or false?

True

2

What is meant by comminution?

The reduction of solid materials from a bigger mean particle size to a smaller mean particle size

3

The efficiency of a conventional ball mill is greater than that of a vibratory mill. True or false?

False - vibratory mill more efficient

4

Dry sieving is usually more efficient than wet sieving. True or false?

False - wet sieving is more efficient

5

Which milling method is defined as self-classifying?

Cutter mill

6

Separation efficiency is the effectiveness of a given process in separating particles into oversized and undersized fractions. True or false?

True

7

How many micrometres is a coarse powder?

>350

8

How many micrometres is a medium/fine powder?

100-350

9

How many micrometres is a fine powder?

50-100

10

How many micrometres is a very fine powder?

10-50

11

How many micrometres is a micronised powder?

<10

12

The sieve method is simpler and more cost effective than microscopy. True or false?

True

13

The sieve method provides particle shape information. True or false?

False

14

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

15

Mohs' scale is a quantitative measure of hardness. True or false?

False - qualitative

16

Brinell or vickers is a quantitative measure of hardness true or false?

True

17

Which milling method achieves a particles size of 1-300 micrometres?

Attrition

18

Which milling method achieves a particles size of 100-100,000 micrometres?

Cutting

19

What particle size can a ball mill achieve?

1-200 micrometres

20

Which milling method achieves a particles size of 20-100,00 mircometres?

End runner

21

Which milling method achieves a particle size of 1-1000 micrometres?

Vibration

22

Which milling method achieves a particle size of 600-200,000 micrometres?

Roller

23

What particle size can a fluid energy mill achieve?

1-100,000 micrometres

24

Which milling method achieves a particle size of 10-9,000 micrometres?

Pin mill

25

What particle size does a hammer mill achieve?

30 - 10,000 micrometres