| 摘要 |
<p>Foam glass is manufactured from a molten glass composition which contains at least 0.2 % by weight of FeO and sufficient sulphur to satisfy the Fe++ ion and which has a negative redox value of at least -7 by contacting the molten glass composition with a refractory carbide, nitride or oxynitride capable of acting as a catalyst to produce sulphur dioxide with precipitation of iron. Silicon carbide and silicon oxynitride are preferred materials. The molten glass composition may be stirred using a rod which is 70 % silicon carbide and 30 % silicon nitride or silicon carbide may be sprinkled on the molten glass composition in a furnace. Alternatively, the molten glass composition may be poured from a glass melting furnace over a forehearth of silicon carbide. Precipitated iron and any other metal present are recovered as a by-product of the production of foam glass.</p> |
