Dear Sir,
I'm Andrea Gioia, research engineer of Saint-Gobain in Aubervilliers (France). I'm geologist and my mission is to look for raw materials needed in Saint-Gobain glass manufactures. At the moment I have to evaluate the raw materials availability for a product that will be produce in India.
Producing this glass in other plants around the world, we have find that rocks as nepheline-syenite, phonolite or basalt are well adapted. We could use also K- and Na feldspars but we prefer silica undersaturated rock. Feldspars could be mixed to first rock kinds but in small proportions.
The ratio Al2O3/SiO2 has to be higher than possible. K2O and Na2O have to be high too.
As we are not limited in iron, Al-bearing rock for this glass manufacture can be used raw without expensive deferrization treatments.
So, the main specifications for searched silica rock are here below:
·Al2O3: as much as possible
·K2O: as much as possible, up to 15 wt%
·Na2O: as much as possible, up to 15 wt%
·Grain size 0-1 mm (~ depending on the mineralogical composition)
·Fe2O3 could be accepted up to 10 wt%
We could accept mining by-products generally designed to waste or road construction.
If you agree, you could me propose many materials with their chemical compositions, then I will come back to you with a first screening of the best possibilities. Please, don’t hesitate to send me data on material that are slightly different from my specifications, may be we could adapt them to our glass recipe.
Thanks for you attention!!!!
I look forward to your reply.
Mr. Andrea Gioia