Metals 4: Recycling Of Scarce And Critical Metals

Question 1

What are strategic/critical and scarce metals?

Answer 1

• Critical metals are the metals in strategic applications, also called “strategic metals” (not a scientific definition).
• Can change along time. Critical metals are part of the Critical Raw Materials (CRMs).
• CRMs are raw materials of high importance to the EU economy, high risk associated with their supply.
• In this context: strategic metals = critical metals, which are relatively scarce and rare. Normally used in advanced technologies.

Question 2

What metals are strategic/critical?

Answer 2

In the EU: REEs (light and heavy), Sc, PGMs, Ge, Ga, In, Bi, Be, Sb, Ta, Nb, Hf, Co, W, V, Mg, Si

Question 3

What are the applications of critical metals?

Answer 3

• EEE
• Photovoltaic (solar power system)
• Batteries
• Catalysts
• Magnets

Question 4

How are rare/scarce metals produced?

Answer 4

Mainly as the byproducts of major non-ferrous metals. Byproducts of:

• Lead and zinc: bismuth, germanium, indium
• Nickel: cobalt, some PGMs (e.g. rhodium, palladium), and scandium
• Copper: cobalt, molybdenum, rhenium, selenium, tellurium
• Aluminium (bauxite): gallium
• Iron: light REEs (partially), vanadium

Hard to recover since a large percentage of scarce metals are to be found in the form of very thin layers, or mixed with other substances in the form of alloys.

Question 5

Where do critical metals end up at the end of their life?

Answer 5

A lot in “urban mines”. Major secondary resources of critical metals:

• Electronic waste
  
  • Precious metals: Au, Ag, Pd
  • REEs: Nd, Pr, Dy, In
• PV solar panels: Si, Ga, Ge, Te
• Catalysts: Pt, V, Mo, REEs
• Super alloys: Cr, Mn, Mo, Nb, V
• Wind turbines: REEs (magnets)

Question 6

What are the challenges with recycling of critical metals?

Answer 6

• Precious metals are partly recycled:
  
  • Printed circuit boards, and platinum group metals (PGM) from automobile exhaust pipes, catalysts
• No efficient technology available for recovery in many other applications!
• Difficult to recycle
  
  • Diffused & low concentrate use
  • Mainly manufacturing scrap recycling
• Economically not in favour
  
  • Currently sufficient primary supply => Competition w/ primary production