摘要
为获得新型复合添加剂作用下石煤灰渣二次焙烧的最佳温度条件以及进一步探索复合添加剂促进钒氧化转化的作用机理,针对现有焙烧提钒工艺对广西上林石煤灰渣焙烧转浸率较低的情况,根据上林石煤灰渣的晶体结构以及钒在其中的赋存特点,提出新型复合添加剂(NaCl-CaF2-CaCO3)二次焙烧石煤灰渣提钒的思路。结合XRD、SEM、EDX等技术,对NaCl-CaF2-CaCO3在焙烧过程中的作用机理进行探讨分析。焙烧结果表明,在焙烧温度850℃,焙烧时间30 min,焙烧气氛O2≥5%的条件下,钒浸出率可达80%左右。分析结果表明,只有在复合添加剂作用下打破含钒云母晶格,使钒释放出来,才能在氧化环境下发生V(Ⅲ)→V(Ⅴ)的价态转化反应。
In order to determine the optimum conditions for roasting to maximize vanadium extraction from ash of stone coal,and to identify the mechanisms governing the transition of vanadium oxidation state during composite additives(NaCl-CaF2-CaCO3) roasting,X-ray diffraction(XRD) analysis,scanning electron microscopy(SEM) and energy spectrum analysis(EDX) were used to study the mechanisms involved in transformation of vanadium during composite additives roasting.The roasting results indicated that after a roasting treatment at the optimum condition of 850℃,reburning time 30 min and reburning atmosphere O2≥5%,about 80% vanadium can be leached from the roasted samples.Characterization analysis showed that only if the crystal lattice of mica in which vanadium exist was destroyed by composite additives,V(Ⅲ) can be oxidised into V(Ⅴ) at elevated temperature.
出处
《能源工程》
2012年第3期11-16,24,共7页
Energy Engineering
