铁钙比对煤灰中耐熔矿物生成的抑制机理研究

铁基助熔剂和钙基助熔剂能有效降低煤灰熔融温度,为了研究铁钙比(Fe2O3/CaO)对煤灰中耐熔矿物生成的抑制机理,根据煤灰化学成分组成,在三种不同系列的煤中加入含铁助剂,调整煤中的铁钙比,对煤灰进行灰熔融温度、煤灰成分分析,对还原性气氛下制备的煤灰渣进行X射线衍射分析(XRD).结果表明:加入含铁助剂可降低煤灰熔融温度,在相同铁钙比下,加入Fe助剂的煤灰熔融温度低于加入FeS2助剂的煤灰熔融温度,硫在煤灰中起增加煤灰熔融温度的作用;煤灰中铁钙比不同对高熔点矿物的生成影响不同,当铁钙比在1~2间时,灰渣中仅有钙长石,当铁钙比在3.5~5.5间时,灰渣中既有钙长石的也有耐熔矿物莫来石的存在,煤灰中铁质矿物和钙质矿物的含量对耐熔矿物的生成有很大影响.

Inhibition Mechanism of the Ratio of Fe2O3/CaO on Formation of Refractory Mineral in Coal Ash

The coal ash fusion temperature was obviously reduced by adding iron-based flux and calcium-based flux. In order to research the inhibition mechanism of the ratio of Fe2O3/CaO on formation of refractory mineral in coal ash,according to coal ash composition,iron-containing flux was added to three different series of coal to adjust the ratio of Fe2O3/CaO. Coal ash fusion temperature and coal ash composition were analyzed. Meanwhile,the crystalline mineral composition of coal ash slag prepared in reducing atmosphere was analyzed by X-ray diffraction (XRD ). The results show that addition of iron-containing flux can decrease coal ash fusion temperature. Under the same ratio of Fe2O3/CaO,the ash fusion temperature added with Fe flux is lower than that of FeS2 flux,and sulfur in coal ash plays the role of increasing fusion temperature. Different ratios of Fe2O3/CaO have different influence on the formation of high melting point mineral. When the ratio of Fe2O3/CaO is within 1-2,there are only anorthite in the slag. When the ratio of Fe2O3/CaO is within 3. 5-5. 5,there are both anorthite and refractory mineral mullite. And the content of iron and calcium minerals have a significant effect on the formation of refractory mineral.