Recycling (Not coming up)

Question 1

What are the 3 stages of Material Recovery Facilities?

Answer 1

1) Material Preparation
2) Primary Separation
3) Material Recovery

Question 2

What is MRF?

Answer 2

Material Recovery Facilities

Question 3

Key aspects of the Preparation Stage?

Answer 3

1) Bag Splitting
2) Removing of Large Objects
3) Feedstock prepared for effective seperation

Question 4

What is the primary stage?

Answer 4

Crude separation to ensure more effective and efficient recovery stage

Question 5

What is Clean MRF?

Answer 5

Recyclables are recovered

1) rubbish and mixed recycling collection
2) disc screening

Question 6

What is Dirty MRF?

Answer 6

Recyclables recovered from municipal solid waste

Question 7

What is the recovery stage?

Answer 7

Final phase dependant on end recyclate and market requirements.
Segregation can be manual or automated
Sorting equipment includes overband magnets, eddy current separators, optical sorters and air classifiers.

Question 8

Advantages of Dirty MRF

Answer 8

No presorting
- save labour and space to segregate the waste at soruce
Feedstock incude Mixed Waste

Question 9

Advantages of clean MRF

Answer 9

1) Better quality materials
2) Less contamination
3) Cleaner - as not mixed with organic waste
4) Feedstock depend on collection

Question 10

Types of Mechanical Separation?

Answer 10

1) Negative Sorting
- passive
- gravity or air jets
- screens

2) Positive Sorting
- Active Removal
- Manually or Mechanically
- e.g. magnetic seperation

Question 11

What is a disc screen Separator?

Answer 11

• rotating discs
• larger objects rise to top
• smaller objects settle at the bottom

Question 12

What is a debris roll screen?

Answer 12

Oval shape rollers or dics create a wave action in the incoming waste
- releases smaller materials through screen opening

Question 13

What is Optical Separation?

Answer 13

• Distinguish between different types of recyclable materials
• use infra- red, x-ray, pattern recognition
• Materials targeted, PET, HDPE, Heavy paper, Ceramics.
• Through puts slow

Question 14

What is Baling?

Answer 14

Recyclables are compacted into bales tied with wire or plastic strapping

Question 15

By products of Recycling?

Answer 15

1) Dry recyclables are reprocessed into new products
2) Organic waste
- composted
- landfil

Question 16

What is driving separation of more material?

Answer 16

1) Increasing recycling and recovery targets
2) Research and development
3) Improving cost efficiency
- further use of computers

Question 17

What is autoclaving?

Answer 17

Processing of MSW in a pressurised sealed drum under the action of steam

Question 18

What are the by products of Autoclaving?

Answer 18

• Autoclave fluff - 50% reduced biodegradability
• Refuse Derived fuel (RDF)
• paper fibre
• Ethanol production
• Biogas Production - Anaerobic digestion
• Clean dry recyclables e.g. glass. metals
• Effluent stream or condensate
• Low calorific residues to landfill

Question 19

Autoclaving Strengths (+)

Answer 19

1) Proven on MSW application
2) process sterilises waste
3) heat deformation of plastics may enhance efficiency for recycling
i. e. removing of labels and glue
4) Lowers maintenance requirements at combustion facilities
5) Substantial reduction of ash and other products destined for landfills

Question 20

Autoclaving Weaknesses (-)

Answer 20

1) Perceived as new technology
2) Underdeveloped markets for recovered fibre
3) Products of combustion would result from subsequent use of RDF for energy recovery