Selenium is a compound often used as colourant in coloured glass batches such as grey, bronze, pink etc. On the other hand, selenium can also be used in clar glass batches as decolourizing agent. Depending upon the raw material used in the batches as selenium source, 30-90% of it either evaporates during the melting process or remains in colourless form. This will lead to an increase in the batch cost, and colour stability problems. Besides those effects it can cause environmental problems as well. the oxidation state of selenium retained in the glass, is affected by several parameters such as furnace atmosphere, melting temperature, pull rate indicating the residence time and finally the amount of oxidizing and reducing agents taking part in the glass batch. An experimental study was carried out in order to investigate the parameters that affect the selenium retention in the glass. The correlation between selenium retention and redox level of the glass, as well as the SO3 retention in the glass were examined. This paper will try to summarize those results and states the effects of each parameter.
