PRODUCTS Indium Ingots

Intai Indium Ingots

The primary commercial application of indium is in coatings for the flat panel display industry. Indium is only useful when chemically processed with tin-oxide to form indium-tin-oxide (ITO) to allow for electrical conductivity and optical transparency. Sputtering targets are placed in a vacuum and since ITO is conductive and optically transparent, thin layers of ITO are then applied as electrical contacts onto glass, which can in turn be used as Liquid Crystal Display (LCD) on electronic devices like television sets, computers and mobile phones. The ITO transparent conductor is popularly used in LCD technology due to its unique qualities of low melting point, good uniformity (which is suitable for large LCDs), fast etching time and long life span.

Indium is also a crucial raw material for solar energy technology. Copper Indium Gallium Selenide (CIGS)
is a new semi-conductor material comprising of copper, indium, gallium, and selenium. Its main use is for
high-efficiency photovoltaic cells (CIGS cells), in the form of thin-film photovoltaic. The thin-film
photovoltaic has several advantages over traditional solar energy technologies. It is lightweight, can be
applied on uneven surfaces and can be rolled up when not in use.

Production Process
The basic steps involved in the production processes relating to our various products are as follows:

Roasting: Zinc concentrate is desulfurised and converted to zinc calcine ore by heating the concentrate
in a roaster at high temperatures.

Leaching: After the zinc calcine ore has cooled, it is leached in acid solution to form zinc sulphate
solution, indium slag and leached slag. The indium slag is then used in the production of indium whilst
the leached slag is used in the extraction of strip liquor (Please refer to by-products production process).

Baking: Indium-free fine coal is used to bake the indium slags at high temperatures in the rotary kiln to
produce the semi-finished product comprising rotary kiln powder.

Soaking: The rotary kiln powder is soaked in sulphuric acid to produce indium liquor.

Purification and extraction: The indium liquor is put through a purification process to displace impurities
such as zinc and lead. After several rounds of purification, extracting agents are then added to the
purified indium liquor to extract strip liquor.

Displacement: The strip liquor is then passed into a displacement tank using zinc metal plates as
displacers to produce indium sponge.

Pressing and soda boiling: The indium sponge is then pressed by a compressor to remove water. It is
then melted using caustic soda as a melting agent and a suitable removal agent is added to remove
impurities. The melted indium solution is then poured into the moulding board to cast the sheet, which
will become coarse indium after cooling.

Electrolysis and ingot casting: The most essential step in indium ingots production comprises putting
coarse indium into the electrobath to carry out electrolysis purification, the end-result of which is to
produce high purity indium. The high purity indium is peeled off, melted into indium solution and poured
into the mould to cast into ingots. The indium ingots are then packed in accordance with marketstandard
specifications.

Commercial Applications

Industrial Applications