(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 國(guó)家重金屬污染防治工程技術(shù)研究中心，長(zhǎng)沙 410083)
摘 要: 針對(duì)高鐵鋅焙砂現(xiàn)有冶煉方法的不足提出選擇性還原-浸出處理鋅焙砂工藝。鋅焙砂中鋅鐵主要物相為鐵酸鋅，首先采用熱力學(xué)軟件Factsage對(duì)鐵酸鋅還原過(guò)程進(jìn)行分析，得出鐵酸鋅選擇性還原控制條件，并結(jié)合熱重分析和化學(xué)分析對(duì)熱力學(xué)分析結(jié)果進(jìn)行驗(yàn)證。結(jié)果表明：以可溶性鋅和亞鐵含量為評(píng)價(jià)指標(biāo)的最佳磁化焙燒條件為焙燒時(shí)間60 min，焙燒溫度750 ℃，CO分壓8%(體積分?jǐn)?shù))，VCO/(VCO+VCO2)氣氛比30%，此時(shí)的占總鋅比率(可溶鋅率)為91.89%，亞鐵占總鐵的比例(亞鐵率)為51.19%。將上述理論計(jì)算和分析結(jié)果應(yīng)用于鋅焙砂處理，焙燒產(chǎn)物中的鋅通過(guò)酸浸回收，鐵以磁性氧化鐵形式賦存于焙砂中；以鐵鋅浸出率為考察指標(biāo)得出最佳浸出條件為溫度30 ℃、初始酸度90 g/L、液固比10:1、反應(yīng)時(shí)間10 min，此時(shí)選擇性浸出效果較為理想。
關(guān)鍵字: 鐵酸鋅；鋅焙砂；磁化焙燒；浸出
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,
Central South University, Changsha 410083, China）
Abstract:A kind of selective reduction roasting-leaching process which is against deficiencies of existing treatment of zinc calcine was proposed. The Factsage 6.2 program was used for the thermodynamic analysis of the selective reduction and the optimal roasting condition was obtained. Then, TG analysis and chemical analysis of zinc ferrite was applied to verify the results of thermodynamic analysis. The results show that using the content of soluble zinc and ferrous iron as the evaluation index of the reduction roasting, the optimal roasting conditions are obtained as follows: roasting time of 60 min, roasting temperature of 750 ℃, CO volume fraction of 8%, VCO/(VCO+VCO2) of 30%. The soluble zinc ratio of 91.89% (mass fraction) and ferrous iron content of 51.19% in the total iron content are achieved. Then, this roasting method was applied in the treatment of zinc calcine, the roasting product was subjected to acid leaching to recover zinc, and iron remains in residues as magnetite. The optimum leaching conditions with the leaching efficiency of zinc and iron as the evaluation index are obtained as follows: leaching temperature of 30℃, sulfuric acid concentration of 90 g/L, liquid to solid ratio of 10:1 and leaching time of 30 min.
Key words: zinc ferrite; zinc calcine; magnetic roasting; leaching
