CAR Material Selection & Properties 5

Question 1

What is 'prepared 1' (P1) grade copper scrap, and why is it relevant to appliance recycling?

Accepted Answer

Copper with less than 0.5% impurities, achieved by stripping insulation from motor windings

Answer

Any copper alloy containing more than 50% copper content

Answer

Copper tubing still attached to aluminum fins requiring separation

Answer

Bare bright copper wire only from new construction

Question 2

Polystyrene (PS) inner door liners in refrigerators are identified by which resin code and property?

Accepted Answer

#6, brittle and produces a metallic ring when tapped

Answer

#2, flexible and semi-translucent with waxy feel

Answer

#4, stretchy and difficult to tear

Answer

##3, rigid with a chlorine smell when burned

Question 3

In the context of appliance shredder residue (ASR), the 'fluff' fraction primarily consists of:

Accepted Answer

Mixed plastics, foam, rubber, glass, and dirt classified as waste

Answer

High-value copper and aluminum fines requiring further sorting

Answer

Iron and steel particles that escaped the magnetic separator

Answer

Refrigerant oil and grease absorbed in absorbent material

Question 4

Why is it important to identify whether an appliance uses R-410A versus R-22 refrigerant before recovery?

Accepted Answer

They require different recovery equipment and cylinders; mixing them creates contaminated waste refrigerant

Answer

R-410A is not regulated while R-22 requires EPA Section 608 certification

Answer

R-22 can be vented legally while R-410A cannot

Answer

They have identical pressures, so only the label matters for documentation

Question 5

Ballasts in older fluorescent light fixtures found in commercial refrigeration cases may contain:

Accepted Answer

PCB-containing dielectric oil requiring hazardous waste management

Answer

Liquid mercury for starting the lamp

Answer

Radioactive isotopes for ionization assistance

Answer

Elemental sodium dissolved in mineral oil

Question 6

The 'decoating' or 'delacquering' process applied to aluminum scrap from appliances serves to:

Accepted Answer

Remove paint and coatings to reduce slag and improve melt quality

Answer

Add alloy elements to increase aluminum purity above 99%

Answer

Separate aluminum from copper in heat exchanger coils

Answer

Increase the magnetic susceptibility of aluminum for easier sorting

Question 7

Which ASTM standard classification system is most relevant for grading recovered ferrous scrap from appliances?

Accepted Answer

Institute of Scrap Recycling Industries (ISRI) Scrap Specifications Circular

Answer

ASTM A36 for structural steel specifications

Answer

ASTM D638 for plastic tensile properties

Answer

Society of Automotive Engineers (SAE) alloy designations