(1. 北京科技大學(xué) 土木與環(huán)境工程學(xué)院，北京 100083； 2. 清華大學(xué) 環(huán)境學(xué)院，北京 100084)
摘 要: 針對(duì)內(nèi)配煤直接還原鈦磁鐵礦引入灰分和雜質(zhì)從而降低鈦產(chǎn)品品位的問題，利用包埋法進(jìn)行直接還原，將無碳球團(tuán)包埋在煤中，并分別以螢石和硫酸鈉為添加劑，探討此工藝的可行性及添加劑對(duì)還原的影響。結(jié)果表明：利用此工藝可實(shí)現(xiàn)鐵還原的同時(shí)獲得高品位鈦產(chǎn)品的目標(biāo)，且添加硫酸鈉的效果優(yōu)于添加螢石的效果；添加適量的螢石或硫酸鈉均促進(jìn)鈦磁鐵礦的還原，鈦礦物由含鈦低的鈦鐵尖晶石向含鈦高的鈦鐵礦和亞鐵板鈦礦轉(zhuǎn)變。金屬鐵顆粒長大有利于鈦鐵分離并分別富集，鈣長石、霞石和FeS的形成是分別促進(jìn)鐵顆粒長大的原因，但添加過量的螢石和硫酸鈉導(dǎo)致還原生成的金屬鐵聚集相連，阻礙氣體擴(kuò)散，不利于含鈦礦物的還原。
關(guān)鍵字: 海濱鈦磁鐵礦；直接還原；鈦鐵分離；螢石；硫酸鈉
（1. School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China; 2. School of Environment, Tsinghua University, Beijing 100084, China）
Abstract:The problem of coal-based direct reduction of titanomagnetite ore is that the coal ash and impurities are disadvantageous to obtaining a high-grade titanium product. To solve this problem, this study used embedding direct-reduction where pellets without coal were embedded under the coal to be reduced and fluorite and sodium sulfate were used as additives, respectively. The purpose is to demonstrate the feasibility of this process and study the effect of additives on the reduction. The results show that good direct reduction iron powder(DRIP) and titanium concentrate may simultaneously be achieved through this process, and addition of sodium sulfate is more effective than that of fluorite. The suitable addition of fluorite and sodium sulfate are conducive to the reduction of titanomagnetite, the ulvospinel are further reduced to ilmenite and ferrous pseudobrookite. The metallic iron particles grow up when the additives are added, and the reason is that the generation of anorthite, nepheline and FeS are beneficial to the growth of iron particles, respectively. However, a metallic iron shell is formed by the excess additives, which inhibits the reduction gas from entering into the pellets and the reduction of titanomagnetite.
Key words: beach titanomagnetite; direct-reduction; titanium and iron separation; fluorite; sodium sulfate
