准东煤O_2/CO_2燃烧过程中硅铝矿物添加剂对钠/钙/铁释放与迁移的影响

Influences of Salic Mineral Additives on Release and Migration of Na/Ca/Fe during O_2/CO_2 Combustion of Zhundong Coals

新疆准东地区煤炭资源丰富,但锅炉燃用准东煤极易发生受热面积灰结渣等问题,严重制约了新疆地区煤炭资源的大规模利用。本文通过高温管式炉电加热实验系统,研究了4种硅铝矿物添加剂(Al_2O_3、SiO_2、高岭土、硅藻土)对准东煤O_2/CO_2燃烧成灰特性及Na/Ca/Fe元素迁移转化的影响。实验结果表明:准东煤中的钠元素主要以水溶性Na存在,钙元素主要以乙酸溶性和盐酸溶性两种形式存在,而铁元素主要以盐酸溶性和不溶性Fe存在。加入添加剂之后,灰中水溶性Na含量显著减少,不溶性Na含量增加,硅铝矿物添加剂会导致灰中水溶性Na向不溶性Na迁移转化。加入添加剂之后,准东煤燃烧后灰样中乙酸溶性钙有减小趋势,硅藻土对不同赋存形态Fe之间转换的影响效果最为明显。燃烧温度的升高有利于各种金属矿物元素的释放,各金属元素释放量随着燃烧温度的变化程度与其各自的赋存形态密切相关。

There is huge coal reserve in the Zhundong area in XinJiang province of China,while the serious slagging and fouling problems have limited the large-scale utilization of Zhundong coals.Here,the influences of four salic mineral additives on release and migration of Na/Ca/Fe during O2/CO2combustion of Zhundong coals were experimentally explored.Sodium in Zhundong coals was mainly water soluble,calcium was mainly acetic acid and HCl soluble,and iron was mainly HCl soluble and insoluble.The content of water-soluble sodium in coal ash was reduced with salic mineral additives.The introduction of additive led to more water-soluble sodium converting to insoluble form.The calcium content of acetic acid soluble form exhibited a decrease trend with addition of salic minerals,while diatomite had the most effect on iron migration.The increase of temperature is beneficial for release of Na/Ca/Fe,while the release ratio is highly related to occurrence modes.