磁铁矿协同增强磁黄铁矿去除水体中六价铬  

A Study on the removal of Cr(Ⅵ)from aqueous solution using the synergistically enhanced pyrrhotite by magnetite

作　　者：姬翔 丁竑瑞[1] 黎晏彰 鲁安怀[1] 王长秋[1] 李艳[1] JI Xiang;DING Hong-rui;LI Yan-zhang;LU An-huai;WANG Chang-qiu;LI Yan(Key Laboratory of Orogenic Belts and Crustal Evolution of Ministry of Education and Beijing Key Labroratory of Mineral Environmental Function,School of Earth and Space Sciences,Peking University,Beijing 100871,China)

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室及矿物环境功能北京市重点实验室,北京100871

出　　处：《矿物学报》2021年第2期120-126,共7页Acta Mineralogica Sinica

基　　金：国家重点研发计划(编号:2019YFC1805900)。

摘　　要：利用天然磁铁矿辅助合成磁黄铁矿去除水体中的Cr(Ⅵ)。实验结果表明,磁铁矿对合成的磁黄铁矿去除水体中Cr(Ⅵ)过程存在协同增强作用。同时利用X射线衍射分析(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)及能谱仪(EDS)对反应前后样品进行分析,发现水体中的Cr(Ⅵ)被有效的还原为Cr(Ⅲ),并以Cr(OH)_(3)及Cr_(2)O_(3)的形式沉淀。设计正交试验探究了磁铁矿粒度、投加量以及废水pH值对除铬过程中2种矿物间协同作用的影响,发现3种因素的影响作用大小顺序为pH值>磁铁矿粒度>磁铁矿用量。磁铁矿协同磁黄铁矿去除Cr(Ⅵ)的最优条件为pH值=3,磁铁矿粒度75~150μm,用量占比40%。讨论得出2种矿物间的协同作用应包括(1)磁铁矿对磁黄铁矿在水溶液中团聚现象的抑制作用;(2)酸性条件下磁铁矿表面Fe(Ⅲ)对溶液中磁黄铁矿释放H2S的固定作用。In this paper,natural magnetite was used to assist artificially synthesized pyrrhotite for removing hexavalent chromium from aqueous solution.Experimental results had verified that there is synergistic enhancement effect between magnetite and artificially synthesized pyrrhotite in the process of the removal of hexavalent chromium.By using X ray diffraction analysis(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),and the X-ray energy dispersive spectroscopy(EDS),the original samples and reacted samples were analyzed.We have found that the hexavalent chromium in the aqueous solution is effectively reduced into the trivalent chromium,by the artificially synthesized pyrrhotite with assistance of magnetite,which was then precipitated in the form of Cr(OH)_(3)and Cr_(2)O_(3)in the aqueous solution.The orthogonal experiment was designed to explore the influences of magnetite particle size,adding dosage,and pH value of wastewater on the synergistic effect between pyrrhotite and magnetite in the process of chromium removal from the aqueous solution.It was found that influences of these three factors was reduced in following order from the pH value of aqueous solution,to the particle size of magnetite,and to the dosage of added magnetite.The optimal condition for removal of Cr(Ⅵ)using pyrrhotite synergistically enhanced by magnetite was given as pH value of 3 for the solution,particle size of 7-150μm for the magnetite,and the magnetite/pyrrhotite rate of 40%.It is concluded that the synergy between these two minerals should include(1)the inhibition of magnetite on the agglomeration of pyrrhotite in aqueous solution and(2)the fixation of surficial Fe(Ⅲ)of magnetite on the released H2S from pyrrhotite in solution under acidic condition.

关 键 词：磁铁矿 磁黄铁矿 Cr(Ⅵ) 协同作用 

分 类 号：P579[天文地球—矿物学] X52[天文地球—地质学]