L7 - Recycling technologies

Re-use

Re-use

basically things are not thrown out but used again

Recycle

recovery operation, waste is reprocessed into products

How much does 1 ton of scrap iron save?

500-600kg coke and 65kg of oil

How much does 1 ton of waste plastics save?

2.5tonnes of oil

How much does 1 ton of waste copper save?

140tonnes of ore

What opportunities does recycling have?

use of secondary raw materials, reduction of waste costs, job opportunities, public interest, protection of natural resources

Steps of waste recycling

1. Collect (different methods)

2. Manufacture

3. Buy

What are the economic and environmental barriers of recycling?

1. legislature

2. Dependence on landfill

3. High cost for some materials

What are the technological barriers of recycling?

contamination of material

What are the two main groups of contaminants?

irremovable (can’t be removed), removable (can be removed)

Why does contamination of recycling happen?

wrong sorting, not cleaned

Recycling metals - what affect the recyclability?

Other metals present

Recycling paper - what affect the recyclability?

permitted amout of contaminants

Recycling plastic- what affect the recyclability?

different polymer types need to be sorted

Recycling glass- what affect the recyclability?

contaminants - affect aesthetic

Different methods of sorting?

Manual, automatic

Steps for re-pulping paper

1. Precleaning

2. Refining

3. (de-inking)

4. Final cleaning

5. Thickening

6. Drying

What do chemical repulpings used for higher quality product require?

Removal of ink trhough bleaching

What is the most recycled material in EU?

1. Paper

2. Metal

3. Glass

4. Plastic

What temperature is glass being melted?

1450-1550°C

What temperature do heat resistant glass melt at?

1600-2400°C

What are the barriers of glass recycling?

Different chemical composition, Hard to melt impurities, Unsuitable packaging

What requirements do plastics have to have in order to be recyclable?

Sorted by polymer types, clean

2 ways in which waste plastics can be used:

Material, energetically

2 types of cecyclable metals:

Ferrous, non-ferrous

What types of materials are indefinitely recyclable?

Metals, glass

2 names of processing of metals?

Basic oxygen furnace, electric arc furnace