(昆明理工大學(xué) 冶金與能源工程學(xué)院，昆明 650093)
摘 要: 針對鋅含量較高的高爐瓦斯灰無法直接返回?zé)掕F流程循環(huán)使用的問題，采用氨-碳酸銨為浸出劑浸出含鋅高爐瓦斯灰中的鋅，實現(xiàn)了鋅的脫除和高爐瓦斯灰的資源化利用。熱力學(xué)計算和鋅氨配位原理分析表明，通過鋅氨配位浸出實現(xiàn)含鋅瓦斯灰中鋅的脫除是可行的。結(jié)果表明，最佳反應(yīng)條件為氨水濃度2 mol/L、碳酸銨濃度2 mol/L、溫度50 ℃、液固比6:1、浸出時間3 h；在此條件下，鋅浸出率為91%，鐵的浸出率為1.15%，高爐瓦斯灰中的鋅含量從9.54%降低到1.13%，鐵含量由35.9%富集至47.6%。原料和終渣的物相分析表明，原料中以氧化物和硫酸鹽形式存在的鋅溶解浸出，終渣中殘留的鋅主要賦存于難溶解的鋅鐵尖晶石物相中，這是鋅浸出率難以進一步提高的主要原因。SEM-EDS檢測表明，終渣顆粒分布不均勻，表面疏松多孔，有利于高爐瓦斯灰的后續(xù)處理。
關(guān)鍵字: 高爐瓦斯灰；氨-碳酸銨；浸出；鋅
（Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:In view of the problem that the high zinc content blast furnace dust could not directly recycled to iron making process, a novel process for recovering zinc from blast furnace dust and resource utilization of dust was developed by ammonia-ammonium carbonate leaching. The thermodynamic calculation results and zinc-ammonia coordination principle show that removal of zinc from blast furnace dust by ammonia-ammonium carbonate is feasible. And the experimental results show that the optimal reaction condition is as follows: NH3 concentration 2 mol/L, (NH4)2CO3 concentration 2 mol/L, temperature 50 ℃, liquid-to-solid 6:1, leaching time 3h. Under the optimum conditions the leaching rates of zinc and iron are 91% and 0.45%, respectively. The content of zinc decreases from 9.54% to 1.13%, and the content of iron increases from 35.9% to 47.6%. The XRD and SEM-EDS analyses of leaching residue show that the oxides and sulfates of zinc in the raw material are dissolved and leached, the zinc-iron spinel is not leached and present together with the iron oxide in the residue. This is the reason why the leaching rate of zinc is hard to be further improved. Besides, the distribution of the leaching residue particles is uneven, and the surface is loose and porous, which is beneficial to the subsequent treatment of blast furnace dust.
Key words: blast furnace dust; ammonia-ammonium carbonate; leaching; zinc
