煤矸石催化气化耦合气化灰提铝过程中K2CO3和Na2CO3作用的对比研究

Comparative study of K 2CO3 and Na 2CO3 in the process of coal gangue catalytic gasification coupled with aluminum extraction from gasification ash

以煤矸石为研究对象,对比研究了Na2CO3与K2CO3对煤矸石催化气化反应性及催化气化灰中Al的溶出行为的影响。同时,采用X射线衍射分析(XRD)和热重分析(TGA)研究了不同催化剂及温度作用下矸石中矿物质的热转变过程。结果表明,与K2CO3相比,煤矸石中的高岭石更容易与Na2CO3反应生成钠霞石,而酸浸可实现钠霞石中铝和硅元素的有效分离。此外,Na2CO3作为催化剂时,所得气化灰经盐酸浸取后铝的浸出率可达到94.2%。而K2CO3作催化剂时,其铝的浸出率只有83.7%。因此,对矸石催化气化耦合气化灰的铝提取来说,Na2CO3催化剂具有更好的选择性。

Coal gangue as the research object of this study,the effects of Na 2CO 3 and K 2CO 3 on the gasification reactivity and the dissolution behavior of Al from catalytic gasification were compared.At the same time,X-ray diffraction(XRD)and thermogravimetric analysis(TGA)were used to analyze the thermal-conversion process of mineral in coal gangue with different catalysts and at different temperatures.The results show that compared with K 2CO 3,Na 2CO 3 can react more easily with the kaolinite in coal gangue to form nepheline,which can achieve effective separation of aluminum and silicon by acid leaching.Moreover,using Na 2CO 3 as catalyst,the Al extraction rate of gasification ash treated by hydrochloric acid can reach 92.3%,while it can only reach 83.7%using K 2CO 3 as catalyst.Therefore,Na 2CO 3 has better selectivity for the coal gangue catalytic gasification coupled with aluminum extraction from gasification ash.