The Use Of Platinum In Glass Manufacturing
Glass is manufactured by the melting of specific minerals including silicates and potash to temperatures that often reach and exceed 1700 degrees Celsius. In order to craft containers and molds that can not only withstand these temperatures, but also hold up under the abrasiveness of molten glass, platinum and alloys of rhodium and platinum are used. The high melting point and resistance to corrosion make platinum the most likely material for use under these conditions. Platinum and the various alloys, unlike most base metals, do not react with the molten glass, resulting in a much more pure glass mixture than has been previously available with molds and equipment made from other metals.
The platinum used does not oxidize at these extremely high temperatures and will not scale. By adding from 5% to 30% rhodium as an alloy it is possible to make the platinum even stronger and more wear resilient, which in turn extends the life of all of the equipment significantly. Manufacturing the glass component of the Liquid Crystal Display is said to be the most extensive use of both platinum and rhodium in the industry. There are two reasons for this, first the quality of the glass that is required to make computer monitors and digital watches and secondly that the glass is heated to a minimum of 1650 degrees Celsius. This glass is typically no more than 0.5 mm thick and must be absolutely flawless in order to be used for this particular application.
When manufacturing optical quality glass you will find that platinum plays a very large roll in all phases of manufacture including melting, conditioning and forming the glass. The platinum used for this purpose must be pure as the use of alloys such as rhodium and iridium has been found to cause discoloration of the glass, which is completely unacceptable in this type of application. With the high demand for the purest quality glass in applications such as electronics and the medical field, the demand for platinum has skyrocketed. No longer a simple resource for jewelry or electronics this precious metal is now considered to be one of the better investments as the sources of the raw materials are somewhat limited.