By desilication treatment,the Al2O3/SiO2 molar ratio of coal fly ash could be improved to the range of 1.63-2.0.The desilicated coal fly ash(DSCFA)was enriched in alumina extraction.A processing technology was developed for alumina extraction from the DSCFA with the lime sintering process.Ca/(SiO2+TiO2)molar ratio,and NaO/Al2O3 molar ratio,sintering time,and temperature were the most significant parameters impacting on the aluminum extraction efficiency.The optima aluminum extraction efficiency was obtained under conditions of Ca/(SiO2+TiO2)molar ratio of 2.0,NaO/Al2O3 molar ratio of 0.98,and sintering at 1 200 ℃for 60 min.Astandard industrial dissolution method was used under conditions of caustic ratio(αk=n(NaO)/n(Al2O3)of 2.0,Al2O3 concentration of 50 g/L,sodium hydroxide concentration(Nk)of 60.78 g/L,Na2CO3 concentration of 10 g/L,temperature of 85℃, and dissolution duration of 10 min.The final aluminum extraction efficiency was 90%.
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机译：通过脱硅处理，可以将粉煤灰的Al2O3 / SiO2摩尔比提高到1.63-2.0的范围。对脱硅粉煤灰（DSCFA）进行了氧化铝的富集。开发了一种从DSCFA中提取氧化铝的工艺技术Ca /（SiO2 + TiO2）摩尔比，NaO / Al2O3摩尔比，烧结时间和温度是影响铝提取效率的最重要参数。在以下条件下可获得最佳的铝提取效率： Ca /（SiO2 + TiO2）摩尔比为2.0，NaO / Al2O3摩尔比为0.98，在1200℃下烧结60分钟。在苛性比（αk= n（NaO）/ n （Al2O3）为2.0，Al2O3浓度为50 g / L，氢氧化钠浓度（Nk）为60.78 g / L，Na2CO3浓度为10 g / L，温度为85℃，溶解时间为10分钟。效率为90％。
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