| 摘要 |
In nepheline raw material processing to alumina, raw material grinding during charge mixt. prepn. takes place simultaneously with charge mixt. drying, using sinter-step waste gases. During sintering, the charge mixt. is heated to 900-950 deg.C in 1-3 min. while in suspension. The desilicising and causticising sludges, formed during the subsequent hydrochemical treatment of the sinter material, are returned to sinter-step. The process can be applied to nepheline contg. 20-30 wt. % alumina. Waste, with the exception of recycle material, is used in cement, soda and potash prodn. Fuel consumption during sintering is reduced, e.g. by 0.425 t/t alumina. Output is increased, e.g. 4 times. In first, low temp. quick sinter-step, decarbonising achieved can be 100%. |
