铜闪速熔炼炉渣中铁橄榄石相固砷机制研究  

Arsenic Solidification Mechanism of Fayalite Phase in Copper Flash Smelting Slag

作　　者：张惠斌 胡彬 徐圣航 曹华珍 吴旻 郑国渠 Zhang Huibin;Hu Bin;Xu Shenghang;Cao Huazhen;Wu Min;Zheng Guoqu(College of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou 310014,China)

机构地区：[1]浙江工业大学材料科学与工程学院,浙江杭州310014

出　　处：《稀有金属》2024年第2期214-224,共11页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51874257)资助。

摘　　要：铜冶炼炉渣含有大量的铁橄榄石相,在闪速熔炼过程中具有较高的固砷潜力。为了厘清铁橄榄石在闪速炉中的固砷条件,以Fe,Fe_(2)O_(3),SiO_(2)和CaHAsO_(4)为原料通过高温烧结过程研究铁橄榄石的形成过程,探讨了气氛和温度对铁橄榄石固砷行为的影响。采用X射线荧光光谱(XRF)、扫描电子显微镜(SEM-EDS)、X射线衍射(XRD)、X射线光电子能谱(XPS)和电感耦合等离子体质谱(ICP-MS)等手段对炉渣和烧结试样的成分、物相、形貌和元素化学状态进行表征,同时采用毒性浸出试验(TCLP)和第一性原理分析铁橄榄石固砷的稳定性。结果表明,Ar下烧结产物为铁橄榄石相,且当烧结温度从1000℃升高至1300℃时,铁橄榄石的砷浸出浓度从131.4 mg·L^(-1)降低到3.563 mg·L^(-1),砷浸出率从35.04%降低到0.19%,展现出比氧化烧结后的Fe_(3)-xSixO_(4)相更高的固砷稳定性。XPS结果表明,空气和Ar下形成的Si-O-As键有利于提高固化渣的稳定性,且Ar气氛和烧结温度的提高可以促进Si-O-As键的形成。第一性原理计算表明,烧结产物中AsO_(4)和SiO_(4)四面体所形成的Si-O-As键以及Fe原子对AsO_(4)结构中O原子的强相互作用是铁橄榄石固化/稳定化砷的主要机制。Copper smelting slag contains a considerable amount of fayalite,which has a high potential for arsenic solidification dur-ing flash smelting process.In order to clarify the conditions of arsenic solidification in fayalite in flash smelting furnace,the formation process of fayalite was studied by high temperature sintering using Fe powder,Fe_(2)O_(3),SiO_(2) and CaHAsO_(4) as raw materials,and the ef-fects of atmosphere including air and argon as well as temperature(1000~1300℃)on the arsenic solidification behaviors of fayalite were discussed.X-ray fluorescence spectroscopy(XRF),scanning electron microscopy(SEM-EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and inductively coupled plasma-mass spectrometry(ICP-MS)were used to characterize the com-position,phase,morphology and chemical states of the copper slag and the sintered samples.Toxicity characteristic leaching proce-dure(TCLP)and first-principles calculation were used to analyze the stability of arsenic solidified in fayalite.The flash smelting slag contained 41.07%~42.59%Fe,27.54%~30.96%SiO_(2),2.07%~2.35%CaO,0.92%~1.28%MgO and 3.13%~3.77%Al_2O_(3).According to the composition of the copper slag,the liquidus temperature was 1100 to 1200℃.XRD and SEM results showed that the main phas-es of slag were fayalite(Fe_(2)SiO_(4)),magnetite(Fe_3O_(4))and silicates,and the arsenic was solidified in fayalite,but not in magnetite.In the sintering experiments,when sintered in the air,the sintered product was granular at 1000 to 1100℃,and the phase compositions were SiO_(2),Fe_(2)O_(3) and Fe_3O_(4).When the sintered temperature at 1200 to 1300℃,the sintered product was molten,and the phase com-positions contained Fe_(3-x)Si_(x)O_(4),Fe_(2)O_(3) and SiO_(2).When sintered in the argon,the products appeared to be porous at 1000 to 1100℃,while the sintered products presented a completely molten state at 1200 to 1300℃.XRD patterns showed that the fayalite phase was formed at 1000 to 1300℃.The results of TCLP showed that the arsenic leaching co

关 键 词：铜闪速熔炼 铁橄榄石 砷 固化/稳定化 毒性浸出 

分 类 号：TF09[冶金工程—冶金物理化学]