(北京科技大學(xué) 土木與環(huán)境工程學(xué)院，北京 100083)
摘 要: 以褐煤為還原劑，采用直接還原−磁選方法對(duì)含鐵39.96%(質(zhì)量分?jǐn)?shù))的水淬銅渣進(jìn)行回收鐵的研究。在原料分析和機(jī)理探討基礎(chǔ)上，提出影響銅渣中鐵回收效果的主要工藝參數(shù)，并進(jìn)行試驗(yàn)確定。結(jié)果表明：在銅渣、褐煤和CaO質(zhì)量比為100:30:10，還原溫度為1 250 ℃ ，焙燒時(shí)間為50 min，再磨細(xì)至85%的焙燒產(chǎn)物粒徑小于43μm的最佳條件下，可獲得鐵品位為92.05%、回收率為81.01%的直接還原鐵粉；經(jīng)直接還原后，銅渣中的鐵橄欖石及磁鐵礦已轉(zhuǎn)變成金屬鐵，所得金屬鐵顆粒的粒度多數(shù)在30 μm以上，且與渣相呈現(xiàn)物理鑲嵌關(guān)系，易于通過磨礦實(shí)現(xiàn)金屬鐵的單體解離，從而用磁選方法回收其中的金屬鐵。
關(guān)鍵字: 銅渣；直接還原；磨礦；磁選；金屬鐵
lignite-based direct reduction followed by magnetic separation
（Civil and Environmental Engineering School，University of Science and Technology Beijing, Beijing 100083, China）
Abstract:In order to recycle iron from copper slag with total iron content (TFe) of 39.96%(mass fraction), a technique with lignite-based direct reduction followed by magnetic separation was presented. After analysis of chemical composition and crystalline phase, according to experimental mechanism, the tests for studying the effects of different parameters on the recovery of iron were carried out. The results show that the optimum parameters are proposed as follows: the mass ratio of copper slag/lignite/CaO is 100:30:10, the reduction temperature is 1 250 ℃, the time is 50 min, and the particle size of 85% roasted product is smaller than 43 μm, under which the direct reduction iron powders with TFe of 92.05% and iron recovery rate of 81.01% are obtained. After reduction, the fayalite (Fe2SiO4) and magnetite (Fe3O4) in copper slag are reduced to metallic iron. The metallic iron particles whose sizes are mainly larger than 30 μm, are loosely supported on the surface of slag particles. So the monomer dissociation of metallic iron particles is easily achieved by grinding, then the dissociated metallic iron particles are recovered via magnetic separation method.
Key words: copper slag; direct reduction; grinding; magnetic separation; metallic iron
