| 摘要 |
<p>The glassy material is refined by adding refining-agent in molten state to a holding vessel maintained under reduced pressure, forming a foam layer and heating the headspace above the layer. Heating is by combustion within the vessel such that flame is directed toward foam and prevailing pressue is not raised above 0.5 atm. Oxidant gas is O- enriched air or eps. O2 alone. Fuel is at least part C-free. H2- combustion prods. are free of C oxides and of N2. Heating can be by plasma torch using H2, O2, He or mixts. thereof as carrier.</p> |
