Hi Sivaranjani,

Nothing except platinum-rhodium will work to melt these glasses without contamination. Any ceramic crucible will be a single use thing and is bound to give you an impurity. Considering that platinum is at its lowest price these days, you can easily buy a 100 ml 90%Pt-10%Rh crucible for about $4000. If you need any further inputs, feel free to contact me.

Ashutosh

Hi Sivaranjani, Electro-Fused Mullite is typically use in a Glass furnace. I don't know your application, but it can be a solution. 

Thank for your answer. I want to melt flourosilicate glass at 1500 C.  I will look into the possibility of  using electro fused mullite. 

There are numerous materials used for crucibles that can handle that temperature range and not react with glass. I would recommend some of the glazed ceramics since they will be most economical.

http://www.alibaba.com/showroom/refractory%252fresistant-2000c-high-temperature%252fceramic-zirconia-crucibles.html

Zirconia Crucibles will be possible economic alternative.

thanks sudeep. & Joseph .. how about alumina crucibles ?  will cracks occur as we quench ?

zirconia and alumina crucibles can be use with full confidence.

 molybdenum and tungsten crucibles are alternative choices.

Hi Sivaranjani,

Nothing except platinum-rhodium will work to melt these glasses without contamination. Any ceramic crucible will be a single use thing and is bound to give you an impurity. Considering that platinum is at its lowest price these days, you can easily buy a 100 ml 90%Pt-10%Rh crucible for about $4000. If you need any further inputs, feel free to contact me.

Ashutosh

Hi Sivaranjani

 alumina crucibles will be possible but you will have a small amount of impurities.

mortazavi

Hello,

From my experience the platinum crucible is the only reliable choice.

I tried to melt some phosphate glasses using an alumina crucible (1 hour, 1200°C), as the alumina crucibles are cheaper than the platinum ones...Later a XRF analysis of my samples pointed that they contained 8% of Al2O3. As there was no Al2O3 in the composition it was incorporated during the melting, because of the crucible (contamination).

Furthermore, these crucibles just support 2 meltings before start to crack (that sometimes occur inside of the furnace).

For these reasons, I highly recommend the platinum crucible.

Enjoyed Meeting with you today. Regarding Crucibles Platinum Rhodium 80/20 is best.but the most expensive. However Alumina, Zirconia and high Density Mullite could be used. I have only used Mullite and Alumina for Mica Glass-ceramics. Need to be careful with the melt temperature (Ie melt at as low a temperature as possible) and you should be able to melt successfully below 1500oC. Regarding a postdoc. Take a look at the EU Cordis Website for a Marie Curie Fellowship.

Yours

Professor Robert Hill

Hello,

I want to reuse the refractory crucible like glory hole. ( Work - close - heat up - work - close ) Which refractory crucible shoul I use without breaking ?

Thank you.

Süleyman

Dr. Ashutosh Goel,

In response to your answer above, I wish to know whether or not, the Pt-Rh10% crucible is non-reactive at high temperature with alkali oxide containing glasses? I somewhere read that Rhodium is attacked by molten alkalis. Please clarify, as I am in a process of buying a Pt crucible, what is the best choice!? Is it stable and non-reactive for all types of glass compositions?

what about graphite crucibles?

graphite crucibles is not suitable for meeting because have impurity

Alumina is better than graphite

I agree with Mesgar: The composition of glass is the criteria for selection.