(1. 中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083；
2. 中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 為了將鋅焙砂中鐵酸鋅選擇性地分解為ZnO和Fe3O4，研究在CO還原焙燒過程中鐵酸鋅的分解行為。采用HSC和Factsage軟件計算鐵酸鋅在CO還原氣氛下分解的熱力學(xué)基礎(chǔ)，再通過回轉(zhuǎn)窯焙燒試驗考察還原焙燒條件對鐵酸鋅分解行為的影響。結(jié)果表明:在適宜的溫度和氣氛下鋅焙砂中的鐵酸鋅能選擇性轉(zhuǎn)化為ZnO和Fe3O4，CO濃度、p(CO)/p(CO+CO2)值、焙燒溫度和時間是影響鐵酸鋅分解的主要因素，提高焙燒溫度、延長時間、增加CO濃度和分壓有利于鐵酸鋅的分解，也會促進FeO的生成；在最佳條件下，鐵酸鋅的分解率近70%，且過還原不嚴重。經(jīng)XRD和SEM/EDS分析，產(chǎn)物主要以ZnO、Fe3O4、ZnS和Zn2SiO4為主，且顆粒粒度較小、疏松多孔及互相包裹嚴重。
關(guān)鍵字: 鐵酸鋅；鋅焙砂；鋅浸渣；還原焙燒；分解行為
（1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:In order to selectively decompose ZnFe2O4 contained in zinc calcine to ZnO and Fe3O4, the decomposition behavior of zinc ferrite during CO reduction roasting process was studied. The thermodynamic basis of ZnFe2O4 decomposition with CO was firstly calculated by HSC and Factsage software, then the effects of reduction roasting conditions on ZnFe2O4 decomposition behavior were investigated by reduction roasting test using rotary kiln. The results show that ZnFe2O4 can be selectively converted into ZnO and Fe3O4 at appropriate temperature and atmosphere. CO concentration, p(CO)/p(CO+CO2), roasting temperature and time have significant effects on the selective decomposition behavior, and increasing them are conducive to the decomposition of ZnFe2O4 and the generation of FeO. Under the optimum condition, the decomposition rate of ZnFe2O4 is nearly 70% without substantive over-reduction of iron. The roasting product mainly composes of ZnO, Fe3O4, ZnS and Zn2SiO4, and the particles are small, loose, porous and seriously mutual encapsulated according to XRD and SEM / EDS analyses.
Key words: zinc ferrite; zinc calcine; zinc residue; reduction roasting; decomposition behavior
