多级孔结构化磁黄铁矿材料制备及除磷性能

发布时间：2018-03-16 00:38

  本文选题：黄铁矿　切入点：针铁矿　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以安徽庐江浮选黄铁矿精粉(FeS2)以及水热合成针铁矿、天然褐铁矿为原材料,通过X射线粉末衍射(XRD)、场发射扫描电镜(FE-SEM)、磁化率仪、热重分析仪等手段,综合分析了安徽庐江浮黄铁矿与针铁矿在N2保护气氛下不同温度焙烧后两种产物的结构、磁化率、升温过程重量损失的演化规律。静态实验考察了不同温度热处理针铁矿层产物新生磁黄铁矿(Npyr)对水中PO43-的净化作用、溶液初始pH值、PO43-初始浓度、反应时间、溶液温度及水中主要阴离子和阳离子对最佳焙烧温度新生磁黄铁矿(Newborn Pyrrhotite, Npyr)净化水中PO43-的作用。结果表明：(1)在氮气气氛下混合焙烧黄铁矿与针铁矿,在500℃时黄铁矿尚未分解,针铁矿脱羟基演变为赤铁矿；在500～600℃时,赤铁矿与黄铁矿分解产生的单质硫发生氧化还原反应首先形成磁铁矿,磁铁矿再与单质硫发生歧化反应形成磁黄铁矿和二氧化硫。(2)针铁矿转变为赤铁矿、磁铁矿的过程中继承了针铁矿的形貌特征,但转变为磁黄铁矿后变成为粒状,并且随着焙烧温度升高形成磁黄铁矿的粒径增大。磁铁矿与单质硫气固相反应转变为磁黄铁矿的晶体生长为螺旋生长。焙烧黄铁矿与天然针铁矿针铁矿层产物对净化水中低浓度磷的最佳焙烧条件为：焙烧温度650℃,焙烧时间2h。(3)新生磁黄铁矿(Npyr)去除磷的最佳pH范围是5-7;溶液中的共存阴离子Cl-,对Npyr样品吸附磷没有显著干扰作用,NO3-对Npyr样品吸附磷有明显促进作用；SO42-, HCO3-对去除率有干扰作用,与PO43-是竞争关系。此外,通过分析动态试验柱的出水溶液中PO43-、Fe2+、SO42浓度,考察了焙烧黄铁矿对溶液中PO43-的净化效果。得出了新生磁黄铁矿对5mg/L以下的含磷溶液去除效果很好去除率接近100%；700℃焙烧黄铁矿动态柱实验在水力停留时间为1.5h的条件下,可以连续运行375天,对1mg/L以下的含磷溶液去除率接近100%。
[Abstract]:In this paper, by means of X-ray powder diffraction (XRDX), field emission scanning electron microscope (SEM), magnetic susceptibility meter, thermogravimetric analyzer and so on, using FeS2), hydrothermal synthetic goethite and natural limonite as raw materials, the authors have made use of FES _ 2), as well as hydrothermal synthetic goethite and limonite. The structure and magnetic susceptibility of the two products calcined at different temperatures in N2 protection atmosphere of Lujiang floating pyrite and goethite in Lujiang, Anhui Province were comprehensively analyzed. The evolution law of weight loss in heating process. Static experiments were carried out to investigate the purification of PO43-, initial pH value of solution, initial concentration of PO43-, and reaction time of pyrrhotite, a product of pyrrhotite layer after heat treatment at different temperatures. The effect of solution temperature and the main anions and cations in water on the purification of water PO43- by neopyrrhotite (npyrr) at the optimum calcination temperature. The results show that the pyrite and goethite are roasted in the atmosphere of nitrogen and the pyrite has not been decomposed at 500 鈩，

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