The viscosity window of the silicate glass foam production.

The production of silicate glass foam allows diverse resources and waste materials to be used in the production. Testing of such large palette of materials complicates and prolongs the optimisation process. Therefore, it is crucial to find a universal criterion for foaming silicate glass melts which can offer a practical starting point for the optimisation procedure. The melt viscosity might be the most important parameter for controlling the foaming process and the glass foam density. In this work, we attempt to define a viscosity range in which foaming of different glasses results in a maximum of foam expansion. The expansion maximum is obtained for different glasses (labware, E-glass, CRT panel, soda-lime-silica) by foaming with CaCO 3 at isokom temperature and from literature data. In general, the viscosity window was found to be within 10 4 –10 6 Pa s when foaming with MnO 2 or metal carbonates (CaCO 3 , Na 2 CO 3 , MgCO 3 , SrCO 3 , dolomite) whereas SiC requires higher temperatures and correspondingly lower viscosities (10 3.3 –10 4.0 Pa s). These findings can help assessing the implementation of new resources in the glass foam production. [ABSTRACT FROM AUTHOR]