Sciencemadness Discussion Board

Electronic gadgets contain 43 elements is that true ?

metalresearcher - 26-10-2010 at 22:48

According to press sources electrocic gadgets (smartphones, mp3 players, laptops, etc.) contain a lot of rare earth metals, tantalum and other rare elements. The press talks about 43 elements which is nearly half of all the 90 available elements in nature.
So costs of rare earths are soaring. I can imagine with the very short economic life cycle of a smartphone (less than 2 years).

Is that really true that a smartphone contains so many elements ?

See also http://en.wikipedia.org/wiki/Rare_earth_element

psychokinetic - 26-10-2010 at 23:48

I don't know specifics, but a lot of them are likely in trace amounts incidentally (i.e. not really put in there for a particular purpose, but rather that they happen to be a part of the material that's used) or are things such as diodes, elemental makeup of the plastics, perhaps also conducting polymers.

I could see how the numbers would shoot up quickly.

dann2 - 27-10-2010 at 05:57


A bucket of sea water probably contains all 90. Most of the weight being Hydrogen and Oxygen!

12AX7 - 27-10-2010 at 08:40

Can we enumerate them?

Biggest:
Oxygen, hydrogen, carbon, nitrogen: plastics, composites
Chlorine, bromine, fluorine: plastics, additives
Silicon: composites, ICs
Sodium, potassium, calcium: composites (e.g. fiberglass)
Magnesium, aluminum, iron, titanium, chromium, manganese, nickel: metal alloys, composites, cermets, etc.
Zinc, copper, silver, gold, palladium, platinum: components, interconnects, plating
Cobalt, lithium: batteries
Phosphorus, boron, gallium, arsenic, germanium: additives, semiconductor dopants, etc.
Molybdenum, tungsten, krypton, xenon: light bulbs, flash tubes
Tin (and lead, but less often these days): solder

That's 33 already. Let's see if I can find 10 more:

Barium, zirconium, lead: capacitors, piezoelectrics
Indium: displays
Neodymium: magnets
Assorted rare earths: phosphors -- maybe 5 are the most significant? (Y, Eu, Er, etc.)

43 sounds pretty close!

Tim

not_important - 27-10-2010 at 10:36

Indium is also used in some shorter wavelength LEDs, besides its use in transparent condive films for flat displays. The RF part may use GaAs, GaN, SiGe, InP, and other mixed IV-V semiconductors. Batteries - Li, S, F, O, and various transition metals depending on the chemistry.

metalresearcher - 27-10-2010 at 11:23

@12AX7 Yes, really !

For semiconductor dopants you forgot Al (same group als Ga and In) but is already mentioned in 'metal alloys'.
But silver and gold ? Silver probably in solders but gold ??
You forgot an inportant one: Ta in capacitors !
Tb , Eu, Dy and Er are used in LED and fluorescent phosphors.

@dann2: A bucket of sea water does not contain 90 elements:
According to
http://en.wikipedia.org/wiki/Abundances_of_the_elements_%28d...

no Tc (obviously),Ru,Rh,Pd, Te, Pm (obviously), Os, Ir, Pt, At, Fr, Ac and beyond U.
Only a minority has more than ppm quantities, even common elements such as Fe are very rare.


psychokinetic - 27-10-2010 at 11:58

No Tc? Radiography machines are electronics.... :P

not_important - 27-10-2010 at 12:18

Technetium is mostly used in compounds for tracer purposes, not in radiography machines. The long lived isotope <sup>99</sup>Tc is a low energy beta emitter, not too useful in radiography. Short lived <sup>99m</sup>Tc is uses as an tracer for imaging, but it's not in the machine but generally injected into the patent.


[Edited on 27-10-2010 by not_important]

psychokinetic - 27-10-2010 at 12:21

Oh, my bad. Not likely to be in electronics until we're cyborgs, then.

dann2 - 27-10-2010 at 14:47


I stand corrected.

Dann2

12AX7 - 27-10-2010 at 20:51

Quote: Originally posted by not_important  
Indium is also used in some shorter wavelength LEDs, besides its use in transparent condive films for flat displays. The RF part may use GaAs, GaN, SiGe, InP, and other mixed IV-V semiconductors. Batteries - Li, S, F, O, and various transition metals depending on the chemistry.


Yes, I only listed elements once (except for lead, which appeared parenthetically the first time). Many of them appear all over the place as noted.

Most electronics contain gold, even if a small amount for IC bonding wires, flash plating on contacts, etc. High reliability equipment generally affords a more profitable amount. And very old equipment can be, well, a mine...

Tim