F6

Question 1

3 different recycle

Answer 1

• Standard recycling: Standard recycled metallurgical products the quality of the product should not be
  diminished when using materials from recycling processes.
• Downcycling: downcycling is the transformation of a product into one of lower quality. In this process, waste
  products can be used for the synthesis of less pure and less valuable products or they can be broken down into
  more basic chemical components; example: titanium chips from aerospace applications into titanium oxide for
  wall-painting.
• Upcycling: the waste products undergo material upgrading and thus attain a higher value than before. The raw
  material undergoes little change and remains relatively true to its original form, saving energy and achieving a
  high degree of sustainability. Example, solid-state electrolysis process for upcycling aluminum scrap

Question 2

Challenges in recycling of mixed metals – impurities

Answer 2

The use of higher scrap levels may result in the introduction of undesirable
impurity levels into the steel.
Some elements intruding from scrap are particularly harmful (such as Cu,
Pb, Sn and Zn), potentially affecting the performance of advanced high-
strength steels
Copper, aluminum, and iron should not be mixed, as they are not
compatible with each other in recycling. This implies for instance that
copper cannot be recovered from an iron melt or aluminum melt. So, mixed
fragments of these metals can never be fully recycled.

Question 3

Which of the following metal has the highest specific carbon dioxide intensity (tonne of carbon dioxide per tonne of metal produced)

Answer 3

Cobalt

Question 4

Which of the following production methods generate the highest carbon emission during the steel production?

Answer 4

Using the blast furnace and oxygen converter

Question 5

Which of the following material can be an alternative material to ITO for the touchscreen?

Answer 5

Graphene