从赤泥中回收铁钛的工艺研究

【作者】 李亮星；

【导师】 廖春发；

【作者基本信息】 江西理工大学 ， 有色金属冶金， 2009， 硕士

【摘要】 二次资源的回收再利用是当今世界环保的一大主题。赤泥是氧化铝生产过程的副产品,每产出1吨氧化铝,产出1～1.8吨的赤泥。赤泥中含有大量的有价金属元素,是一种宝贵的二次资源。本论文归纳了赤泥的国内外利用现状,研究了有价金属在赤泥中赋存状态。针对拜尔法赤泥中铁和钛含量高的特点（铁的含量为19.48%,钛的含量为7.10%）,提出了一种新的回收铁和钛的工艺流程—两段酸浸工艺。首先采用低浓度的盐酸浸出赤泥当中的铁,钛留在渣当中。盐酸浸出工艺最佳参数是:盐酸浓度为2.0mol/L,盐酸过量15%,浸出时间为2.5h,搅拌速度400r/min,Fe的浸出率可以达到95.6%,Ti的浸出率仅为0.5%。通过N235萃取回收浸出液当中的Fe,用20%N235+30%仲辛醇+50%煤油萃取体系,相比O/A=1∶1,振荡混合时间15min,经单级萃取负载有机相含铁12.06g/L,铁的萃取率可以达到99%以上。然后用0.1mol/L的稀盐酸反萃有机相提取铁,在相比O/A=2∶1的条件下,经单级反萃,反萃后液含铁18.12g/L,铁的反萃率为75%。盐酸浸出渣当中含钛28.4%,采用硫酸化焙烧方法,得到的固态反应产物,通过加水浸出,Ti最终以TiOSO₄形式进入溶液。得出工艺最佳参数是:盐酸浸出渣粒度大小为40目、酸解温度为300℃、酸解时间为2.0h、水浸时间为1.0～1.5h、水浸液固比为1∶10、搅拌速度为400r/min。在此条件下进行3次重复试验,得到钛的平均浸出率为99.7%。富钛液经过除杂、水解、煅烧后得到纯度为95%的TiO₂。更多还原

【Abstract】 The recovery and reutilization of the solid waste is the most interesting issue of the environmental protection nowadays. The red mud is a by-product of the alumina generation process, a ton of alumina was produced and output 1-1.8 tons of the red mud. It contains to a large number of metallic elements and is the valuable second resource.The process of recovery the rare metals from red mud were summarized in all the world and my review was gave,and Fe、Ti compose store general situation in red mud. The new process of recovery the rare metals from red mud （Fe is 19.48%, Ti is 7.10%） was studied. It is the craft route of two sections of acid leaching.First of all, using a low concentration of hydrochloric acid leaching of iron among the red mud, titanium was remained in slag. The best parameter of hydrochloric acid leaching process is:the concentration of hydrochloric acid is 2.0mol/L, hydrochloric acid over 15%, leaching time of 2.5h, mixing speed of 400r/min,the leaching rate of Fe is 95.6%, Ti leaching rate only 0.5%.recovery of Fe from Hydrochloric acid leaching solution through N235 extraction, with 20% N235 +30% Octanol +50% kerosene extraction system, O/A =1:1, mixed oscillation time of 15 minutes, after single-stage extraction the organic loads of Fe withe 12.06g/L , Fe extraction rate can reach 99%. With 0.1 mol/L of hydrochloric acid stripping the organic phase of Fe, with O/A =2:1, after the single-stage stripping, stripping liquid Fe 18.12g/L, the stripping rate of Fe is 75%.Hydrochloric acid leaching slag contains 28.4% of titanium ,using sulfuric acid method of roasting, gets the solid-state reaction product, then through the increase of flooding, Ti eventually enter solution in the form of TiOSO₄. It arrives at the optimum process parameters: the particle size of hydrochloric acid leaching residue is 40 head, the acid solution temperature of 300℃, acid solution time for 2.0h, flooding time for 1.0¹.5h, liquid-solid than flooding for 1:10, stirring speed of 400r/min. Repeating the tests for 3 times under these conditions, the average extraction rate of titanium has been 99.7%. With titanium-rich liquid through impurity removal, hydrolysis, after calcination for the purity of 95% TiO₂.更多还原