(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: 利用還原焙燒-堿性浸出工藝處理高鐵鋅焙砂以解決現(xiàn)有煉鋅工藝鋅鐵分離的難題，通過(guò)還原焙燒將高鐵鋅焙砂中鐵酸鋅分解為氧化鋅和鐵氧化物，氧化鋅在堿性體系被選擇性浸出，鐵氧化物賦存于浸出渣中實(shí)現(xiàn)鋅鐵分離。以鋅、鐵浸出率為評(píng)價(jià)指標(biāo)，考察還原焙燒及堿性浸出條件對(duì)鋅鐵分離效果的影響，并對(duì)焙燒產(chǎn)物及浸出渣進(jìn)行XRD、SEM-EDS分析。結(jié)果表明：最佳還原焙燒條件如下，焙燒時(shí)間45？min，焙燒溫度800？℃，CO濃度4%(體積分?jǐn)?shù))；最佳浸出條件如下，NaOH濃度240？g/L，液固比12：1，浸出溫度80？℃，浸出時(shí)間60 min。在最佳條件下總鋅浸出率約為90%，總鐵浸出率約為0.25%，SEM分析顯示：浸出渣中鋅鐵氧化物鑲嵌現(xiàn)象嚴(yán)重，這是鋅浸出率不能進(jìn)一步提高的原因。
關(guān)鍵字: 鐵酸鋅；高鐵鋅焙砂；還原焙燒；堿性浸出
（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:To resolve the problem of zinc-iron separation of zinc ferrite in conventional zinc smelting process, a reduction roasting-alkaline leaching process was proposed. Zinc ferrite in high iron-bearing zinc calcine was decomposed to zinc oxide and iron oxide by reduction roasting, then, zinc oxide was selectively leached in alkaline system, the iron oxide remained in the leaching residues. The effects of roasting conditions and leaching conditions on the separation of zinc-iron were evaluated by the leaching rate of zinc and iron. The roasted products and leaching residues were analyzed by XRD and SEM-EDS. The results show that the optimal roasting condition as follows: roasting temperature of 800？℃, CO concentration of 4% (volume fraction), roasting time of 45？min; the optimal leaching condition is leaching temperature of 80？℃, NaOH concentration of 6？mol/L, liquid-solid ratio of 12:1 and leaching time of 60？min. Under this optimal condition, the leaching rates of zinc and iron are 90.4% and 0.25%, respectively. But the analysis result of SEM-EDS shows that the mosaic phenomenon of zinc oxide and iron oxide in leaching residue is serious, this is the reason why the leaching rate of zinc is hard to be further improved.
Key words: zinc ferrite; high iron-bearing zinc calcine; reduction roasting; alkaline leaching
