(1. 中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用還原焙燒將高鐵鋅焙砂中的鐵酸鋅選擇性地分解為氧化鋅和磁鐵礦，再通過兩段浸出工藝回收鋅，以實(shí)現(xiàn)鋅鐵分離和獲得以磁鐵礦為主的浸出渣。主要考察了還原焙燒、中性浸出及低酸浸出條件對(duì)鋅焙砂中鋅、鐵浸出率的影響。結(jié)果表明：通過還原焙燒可以顯著地提高鋅焙砂的鋅浸出率；中性浸出的最佳條件為浸出溫度60 ℃、液固比10:1、初始酸度45 g/L和浸出時(shí)間2 h；低酸浸出的最佳條件為浸出溫度70 ℃、液固比10:1、初始酸度60 g/L、攪拌速度300 r/min和浸出時(shí)間2 h。在最佳條件下，兩段浸出的總鋅浸出率約為90%，總鐵浸出率約為5%。經(jīng)XRD和SEM/EDS分析，浸出渣以磁鐵礦為主，其次是閃鋅礦和鐵酸鋅；鐵酸鋅存在的主要原因是在還原焙燒過程中被氧化鋅等礦物包裹，使其分解不充分。
關(guān)鍵字: 高鐵鋅焙砂；鐵酸鋅；還原焙燒；浸出
（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:Based on the decomposition of zinc ferrite to ZnO and Fe3O4 by reduction roasting, the recovery of zinc from the roasted zinc calcine was studied by two-stage leaching for zinc-iron separation and the leaching residue containing Fe3O4 was obtained. The effects of reduction roasting and conditions of neutral leaching and acid leaching on leaching rates of zinc and iron were investigated, respectively. The results show that the reduction roasting has a significant effect on recovery of zinc, and the leaching rates of Zn and Fe are about 90% and 5%, respectively. Under the following optimum conditions, which are leaching temperature of 60 ℃, liquid/solid ratio of 10:1, acid concentration of 45 g/L and leaching time of 2 h for neutral leaching, and leaching temperature of 70 ℃, liquid/solid ratio of 10:1, acid concentration of 60 g/L, stirring speed of 300 r/min and leaching time of 2 h for acid leaching. Besides, the main compositions of the residue are Fe3O4, ZnS and ZnFe2O4 according to the XRD and SEM/EDS analysis. The main reason of zinc ferrite left is attributed to the enclosure by other minerals.
Key words: high iron-bearing zinc calcine; zinc ferrite; reduction roasting; leaching
