When Pt is used in high temperature, it is recommended high purity Al2O3 or ZrO2 as a refractory. In general, Fe2O3, SiO2, and MgO are contained in Al2O3 and ZrO2, and they generate adhesive Pt-alloyed chemicals and low m.p. chemicals if they are reduced.
It must be considered that the structure for the heat expansion and contraction of Pt as well as its adhesive capacity in protecting Pt apparatus from refractory.
Since there are ones to react with Pt under the condition of high temperature or melting gas out of new ceramic which preferred as new material in recent, it must be taken care of it.

There may be reduced and alloyed with Pt when it is exposed to reducing flame that SiO2, Sb2O3, CdO, PbO, and As2O3 which sufficiently contained in Gas. They are Pd, Cd, Sn, Zn, As, Sb, Mg, Si which is to be easily reduced and must be taken care for its hazardous property.
When Glass is melted with using Pt Crucible, it shall be used the one which is to be glassed, beforehand melted, without inserting to crucible as its powder condition. Unless the quality decreasing of Pt is to be faster.
For the case of Glass relatively high containing PbO and CdO of easily reduced, it must be careful for mixing of metallic Fe and Al. Al has strong reducing power, so it reduces most of metallic oxides except Mg, Ca, and Ba. Therefore, it is not recommended to used Al-featured containers and devices in processing Glass materials and cullet which melted in Pt Crucible.
In case of melting Glass containing relatively high bubble of CO2 and steam, it is required to consider the structure of apparatus to make weak the bubble.
Make sure not to be attached other foreign bodies of paints and oil-and-fats to Glass material, Pt apparatus and refractories. Moreover, it must be maintained clean and covering since it may be influenced by dust and mote in operation.