(北京科技大學(xué) 土木與環(huán)境工程學(xué)院，北京 100083)
摘 要: 以煤泥為新型還原劑，探索了煤泥用量、CaO與SiO2摩爾比、焙燒溫度以及焙燒時(shí)間等工藝參數(shù)對(duì)浸鋅渣中鉛、鋅、鐵化合物直接還原的影響，分析不同直接還原溫度下還原產(chǎn)物，即焙砂中所含礦物的種類及鐵的存在物相，觀察最佳還原條件下焙砂中鐵顆粒的形貌，最后進(jìn)行了焙砂的磨礦-磁選試驗(yàn)。結(jié)果表明：在煤泥用量45%、CaO與SiO2摩爾比1.2、經(jīng)1250 ℃直接還原90 min后，浸鋅渣中鋅和鉛的揮發(fā)率分別達(dá)到96.69%和97.65%，焙砂中鐵的金屬化率達(dá)到97.78%。鐵在焙砂中主要以金屬鐵顆粒的形式存在，其嵌布粒度多數(shù)＞2 0μm，金屬鐵顆粒與渣相界面分明，表明可通過(guò)磨礦實(shí)現(xiàn)單體解離。采用二段磨礦-磁選流程，可同時(shí)獲得含鐵90.80%的金屬鐵粉和含鐵65%的鐵精礦，鐵的總回收率為81.19%。由此證明煤泥是一種還原效果優(yōu)良的浸鋅渣還原劑。
關(guān)鍵字: 煤泥；還原劑；浸鋅渣；直接還原；有價(jià)金屬
（School of Civil and Environmental Engineering,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The effects of technical parameters, such as the mass ratio of coal slim to zinc-leaching residue, the mole ratio of CaO to SiO2, reduction temperature and time, on the direct reduction of zinc-leaching residue containing zinc, lead and iron compounds were explored using coal slime as a new reducing agent. The types of minerals and iron phase in roasted products generated at different temperatures were analyzed. The morphologies of iron particles in calcine were observed under the optimum reduction condition. Finally, the grinding-magnetic separation tests of the calcine were carried out. The results show that the roasted products with evaporation rates of zinc 96.69% and lead 97.65% in the zinc-leaching residues, metallization rate of iron 97.78% are obtained under optimum conditions of the ratio of coal slim to zinc-leaching residues 45%, mole ratio of CaO to SiO2 1.2, direction reduction at 1250 ℃ for 90 min. The iron in calcine is basically metallic iron. The metallic iron particles size is more than 20 μm. The obvious boundaries can be observed between the metallic iron particles and slag phase, showing the feasibility of monomer dissociation of metallic iron particles. The metallic iron powders with iron grade of 90.80% and iron concentrate with iron grade of 65% are synchronously recovered by two stage grinding-magnetic separation process, and the total iron recovery is 81.19%. Therefore, the coal slime is proved to be a good reducing agent for the direct reduction of zinc-leaching residue. Therefore, the coal slime is proved to be a good reducing agent for the direct reduction of zinc-leaching residue.
Key words: coal slime; reducing agent; zinc leaching residue; direct reduction; valuable metals
