固硫灰的资源化利用研究

发布时间：2018-01-02 13:12

  本文关键词：固硫灰的资源化利用研究　出处：《西南科技大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 固硫灰 资源化利用 铁回收 改性吸附 磁性沸石

【摘要】：为了实现节能减排,我国正大力发展循环流化床技术。固硫灰是循环流化床锅炉燃烧后从烟道收集的飞灰,每年的排放量很大。本论文拟通过研究来自四川内江和贵州毕节固硫灰的基本物化性质,然后针对其特性,进行有用组分的回收和利用,主要包括回收固硫灰中的铁、改性固硫灰的制备以及利用固硫灰制备磁性分子筛等。研究发现,固硫灰中的主要成分是Si O2、Al2O3、Fe2O3,其成分占70%~80%,以石英、硬石膏和赤铁矿为主相,表面粗糙、疏松多孔。在固硫灰中回收铁的研究中,焙烧温度、时间、还原剂用量以及磁场强度的大小均对磁化焙烧-磁选过程有很大影响。添加5%的煤粉作为还原剂,于800℃下还原焙烧90min,在场强200KA/m下经粗磁选,可获得品位51.62%、回收率86.41%的粗铁精矿,再经80KA/m弱磁场强度下精选,铁精矿品位可达58.02%,回收率为76.27%,XRD表明精矿主要矿相为磁铁矿。固硫灰的改性研究表明,改性体系的固液比、改性剂浓度、反应时间以及水浴温度等工艺参数对吸附性能影响较大,其中当利用质量浓度为10%碳酸钠,在80℃下改性2h的时候,SEM显示颗粒表面形成更多孔洞,Zeta电位测试表明,改性灰负于原灰,与金属阳离子存在的静电引力更强。改性灰对重金属Pb2+和Cu2+的吸附去除率达到95.94%和91.35,较原灰提高了20%以上。以固硫灰和Na OH为原料,不添加硅铝源,可制得主相为方钠石的磁性分子筛。体系碱度、晶化温度和时间对沸石的结晶均存在影响,具体表现为碱度越高、晶化温度越高、时间越长,越有利于方钠石的结晶成型。当碱度2.78mol/L,晶化温度为125℃,晶化24h的条件时,结晶度较高,这时对Pb2+的饱和交换吸附量为97.87mg/g,磁性能分析表明,合成的分子筛具有一定磁性,其饱和磁化强度Ms为2.00782emu/g,剩余磁化强度Mr为0.48emu/g,矫顽力Hc=138.2Oe,产物的磁分离效果明显。
[Abstract]:In order to realize energy saving and emission reduction, circulating fluidized bed (CFB) technology is being developed in China. Sulfur fixation ash is the fly ash collected from flue after combustion in CFB boiler. The annual emissions are very large. This paper intends to study the basic physical and chemical properties of sulfur fixing ash from Neijiang and Bijie of Guizhou Province, and then carry out the recovery and utilization of useful components according to its characteristics. It mainly includes the recovery of iron from sulfur fixing ash, the preparation of modified sulfur fixing ash and the preparation of magnetic molecular sieve using sulfur fixing ash. It is found that the main component of sulfur fixing ash is Sio _ 2 / Al _ 2O _ 3 and Fe _ 2O _ 3. The main phase is quartz, anhydrite and hematite. The surface is rough and porous. In the study of iron recovery from sulfur fixing ash, the calcination temperature and time are obtained. The amount of reducing agent and the intensity of magnetic field have great influence on the process of magnetization roasting and magnetic separation. 5% coal powder was added as reducing agent and calcined at 800 鈩，

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