| 摘要 |
Flue dust is foamed by: (a) adding Si nitrite or Si carbide and alkali salts, esp. Na2CO3, dissolved in water and (b) foaming the mixt. at the softening temp. of the flue dust. The flue dust may also be admixed with metal oxide, e.g. MnO2 or Fe2O3, as further foaming agent. The foamed bodies are light, e.g. have density 0.2-0.5 g/cc, have high compressive strength and a low alkali content. The Si nitrite is esp. ferro-silicon nitrite, used in amts. of 2-3 wt.%. |
