Chapter 6 - Aggregate Production

Question 1

What are the 3 ways to excavate rock from the heart of nature?

Answer 1

!) Rock Blasting
2) Cutting with Diamond wire saw
3) Jack Hammer

Question 2

What is aggregate?

Answer 2

A proper mix of gravel, sand, and mineral filler in order to produce the concrete or asphalt

Question 3

What construction projects do you think can use crushed rock?

Answer 3

Highway and Airfield base courses, drainage facilities, railroad truck, asphalt surface treatments, bedding for pipeline

Question 4

What are the 4 steps of aggregate production?

Answer 4

1) Crushing
2) Sizing/Screening
3) Washing
4) Storage and Transport

Question 5

Explain the difference between Jaw Crushers and Impact Crushers

Answer 5

Jaw Crushers are principally used as primary crushers

Impact Crushers include impact breakers, horizontal & vertical shaft impactors, hammermills, & limemills

Question 6

Explain the difference between open and close circuit

Answer 6

Open Circuit: The process of crushing materials in a single pass

Closed Circuit: The process of crushing the same materials in more than one pass

Question 7

How is the optimal screen area determined? (screen capacity)

Answer 7

1) Screen mesh size and its basic capacity
2) Position in the deck
3) Amount of oversize & half-size material
4) Shape
5) Weight factors
6) Material condition

Question 8

What is the main reason for aggregate washing?

Answer 8

To get rid of undesired materials from the crashing. Removing silt, clay and organic material prior to processing and sorting.