Name       : Indium
Symbol     : In
Atomic #   : 49
Atom weight: 114.82
Melting P. : 156.61
Boiling P. : 2080
Oxidation  : +3
Pronounced : IN-di-em
From       : Latin indicum, the color indigo
Identified : Ferdinand Reich and Theodor Richter in 1863
Appearance : Very soft, silvery-white metal
Note       : Used to make low-melting point compounds
             
[Properties]

  Indium is characterized as a soft and malleable, silver-white metal. It
looks a lot like aluminum, but feels more like tin. Like tin, pure indium
emits a squealing sound when it is bent.
  This metal is so soft that you can wipe it onto other objects in much
the same way as you can wipe graphite or pencil lead. Pure indium can be
highly polished, and it will retain the shine because it is corrosion
resistant.
  The low melting point contributes to its commercial value as an alloying
agent for soldering material. Indium is a member of the carbon group of
elements, Group IIIA, on the periodic table.
  Over a thousand kilograms of indium are recovered each year from the flue
dust of zinc refineries. Concentrations from this source are typically on
the order of 1 part per 1000. An acid leaching process allows the indium
to be recovered as indium sulfate from other flue metals such as
aluminum, arsenic, cadmium, and zinc.
  The indium that is recovered from the flue dusts can be purified by
means of an electrolysis procedure. The electrolyte in this case is
aqueous indium sulfate.