氧化还原-盐酸浸出钛铁矿制备富钛料工艺研究

采用氧化还原-盐酸常压搅拌浸出法对钛铁矿进行选择性浸出,研究了氧化还原预处理对钛铁矿粒度、结构、表面形貌的影响,并考察了不同浸出条件对钛铁矿中Fe、Ti浸出率及浸出渣中Ti O_2品位的影响。结果表明,钛铁矿经过氧化还原后颗粒表面粗糙程度增加,粒径有所增大。采用1 000℃氧化1 h,800℃H2还原1 h的改性矿浸出,优化浸出条件为:液固比5∶1,盐酸浓度4 mol/L,反应温度90℃,浸出时间5 h。优化条件下Fe和Ti的浸出率分别为93.89%和3.28%,最终获得Ti O_2品位87.51%的富钛料,同时很好地保持了原矿的粒度。     

钛铁矿和高磷铁矿混合矿氧气顶吹熔融还原炼铁的工艺条件

采用氧气顶吹熔融还原法进行了高磷铁矿和钛铁矿混合矿炼铁的实验研究,考察了熔渣四元碱度、反应温度、碳氧摩尔比、通氧时间、保温时间和氧流量对炼铁效果的影响. 结果表明,提高反应温度、在一定范围内增加CaO加入量、提高碳氧摩尔比、延长通氧时间和保温时间、增加氧流量都能不同程度地提高铁还原率. 确定的合理工艺条件为：温度1500℃,碱度1.3,碳氧摩尔比1.0,保温时间30 min,通氧时间10 min,氧流量350 L/h,在此条件下渣铁分离较好,铁还原率达96.17%.     

选择氯化钛铁矿制取人造金红石

研究了选择氯化钛铁矿制取人造金红石反应的Ｆｅ－Ｔｉ－Ｃ－Ｏ２－Ｃｌ２系平衡图,计算了氧与某些氯化物相互作用的自由能变化,采用“通氧一步选择氯化法”,在钛铁矿原料中配加适量的碳,并往炉内通入相应量的氧气或空气,可以解决选择氯化“自热”反应持续进行的技术关键．对反应参数,如温度、配碳量、物料粒度、氯化时间和通氧量等均进行了实验室、半工业和工业化生产试验研究．研究证明,选择氯化过程的动力学模型是“固体颗粒粒度保持不变的缩核反应模型”,动力学区的活化能为３４．３３ｋＪ／ｍｏｌ;扩散区的活化能为０．８０ｋＪ／ｍｏｌ．试验结果表明,这种选择氯化新工艺具有流程短、产能大、产品质量好、成本低、操作简单等优点．研究开发的无筛板沸腾氯化炉可以长期稳定地连续运转,生产出的人造金红石品位为９２．１０％．经摇床和磁选,品位达到９５％,钛的回收率和氯的利用率都大于９５％,床层单位炉产能达１２．４ｔ／ｍ２ｄ．该工艺和设备已成功地应用于工业生产．     

Study on surface magnetization recover ilmenite from titanaugite using surfactant sodium oleate

ABSTRACT

Separation of ilmenite from titanaugite was investigated by magnetic coating. By enlarging magnetic difference between ilmenite and titanaugite, ilmenite was efficiently recovered. Scanning electron microscope and vibrating sample magnetometer results indicated that magnetite selectively coated onto ilmenite surface and increased its magnetism, which resulted in different magnetic separation behavior between ilmenite and titanaugite. FTIR and contact angle measurements confirmed that the adsorption difference of sodium oleate resulted in a stronger hydrophobicity on magnetite and ilmenite than titanaugite. Interaction energy analysis illustrated that hydrophobic association interaction on ilmenite was stronger than that on titanaugite, and which led to the selective coating of magnetite onto ilmenite.     

Synthesis of Ti(C,O, N) from ilmenite at low temperature by a novel reducing and carbonitriding approach

The clean and effective utilization of titanium-bearing minerals has challenged the titanium industry all over the world. In order to realize the high-efficiency, clean, and high value-added comprehensive utilization of ilmenite concentrate, a novel process has been proposed in this study by reducing and carbonitriding ilmenite with the CH₄-N₂-H₂ gas mixture at low temperature. Carbonitride performance and mechanism have been investigated experimentally and theoretically. The obtained results showed that the reaction process could be divided into three stages: formation of metallic iron, reduction of titanium oxide to titanium suboxides, and formation of Ti(C, O, N). The metallic iron congregated at the first two stages, but dispersed once the Ti(C, O, N) formed. The effects of both reaction temperature and preoxidation treatment on the reaction have been studied as well. It was found that the increase of temperature was conducive to the formation of Ti(C,O), and the ilmenite could be reduced completely to Ti(C,O) at 1170°C for 8 hours. The preoxidation treatment could improve the kinetics of reduction. At 1170°C, the introduction of N₂ could apparently increase the reduction rate, with the complete reduction time decreasing from 8 hours in CH₄-H₂ gas mixture to 3 hours in CH₄-N₂-H₂ gas mixture. The proposed novel process has been assessed and it showed many potential advantages and feasibility.     

硫酸法钛白酸解尾渣工艺矿物学特性分析

采用激光粒度仪、XRD、XRF、ICP-AES、SEM-EDS、比重法、筛分法等对硫酸法钛白生产过程中酸解尾渣进行系统的工艺矿物学特性分析,旨在为回收钛资源提供理论指导。研究表明,酸解尾渣表面潮湿,液相约占45%,其中易水解的可溶钛为4.06%(以TiO₂质量分数计);固相中不溶TiO₂干基含量为17.14%,固相颗粒粒径主要分布于1～100 mm,密度为3.21 g·cm^-3,颗粒大小、形状不一,有块状、锥状及团聚絮状。通过筛分实验得知钛矿与其他杂质颗粒的粒径、密度有明显差异,少量120 mm以上颗粒含有石膏,密度约3.41 g·cm^-3;18～75 mm主要为钛铁矿,密度大于3.54 g·cm^-3,钛品位可达26%;18 mm以下颗粒主要为硅泥,密度约2.90 g·cm^-3,易团聚,与水形成黏稠物,难分离。     

广东岚霞钒钛资源综合回收铁、钛、钒新工艺研究

对广东岚霞钒钛磁铁矿进行了综合回收研究。采用磨矿-弱磁选-强磁选工艺得到钒钛磁铁矿精矿和粗钛精矿, 钒钛磁铁矿精矿和粗钛精矿经隧道窑还原磨选-钠法浸钒, 最终得到了TFe品位92.27%～96.28%的直接还原铁、TiO₂品位55.47%~59.56%的富钛料和98.80%的V₂O₅三种产品, 实现了该矿中铁、钛、钒的综合利用。整个工艺钛、钒的总回收率分别达到73.93%和53.49%, 铁钛钒的综合利用率较传统工艺大幅度提高。     

富氧顶吹熔融还原冶炼高磷铁矿与钛铁矿配矿的试验研究

采用模拟HIsmelt的富氧顶吹熔融还原技术冶炼惠民高磷铁矿与勐桥钛铁矿配矿,在温度为1 500K,碱度为1.3,配碳比为1.0的条件下,恒温时间20min(在升温过程中,没有通入惰性气体),恒温过程中通入O2(流量250L/h、纯度为99%)10min。恒温时间结束后,调整氧气流量为5L/h,保持其氧化性气氛至冷却。研究了不同配矿比例对铁回收率、生铁中磷、硫含量以及磷、硫分配比的影响。研究结果表明,在惠民铁矿和勐桥精矿的比例为1∶1时,其冶炼结果比较理想:铁的回收率为95.1%,生铁中磷的质量分数约为0.32%,硫的质量分数为0.054%,钛的质量分数为0.031%。     

钛精矿流态化预氧化氢还原试验研究

钛精矿流态化氢气还原生产高钛渣技术不仅原料选择范围广、能耗低,而且可实现清洁生产。在冷态试验基础上对钛精矿在高温下先氧化再还原试验进行了探索,研究了温度、还原时间、p(N2)/p(H2)和粒度对金属Fe还原率的影响。试验结果表明:800～950℃,随着还原温度的升高,Fe的金属化率有较明显的增加;在同一温度下,Fe的金属化率随时间延长先快速增加而后趋缓;随着粒径的减小,钛精矿的Fe还原率提高较明显;氢气的浓度对钛精矿还原影响至关重要,随着氢气浓度的增加,还原率有着明显的提高。     

Effect of Temperature on Carbothermic Reduction of Ilmenite

The reduction of ilmenite (FeTiO3) has been studied extensively. Temperature for the carbothermic reduction of ilmenite ranges from 900 ℃ to 1 400 ℃, and the reduction degree of Panzhihua ilmenite increases with increasing temperature. X ray diffraction analysis and SEM analysis were used to identify the phase before and after reduction, and to identify the morphology of reduced samples respectively. It is found that the reaction initiates at about 860 ℃. The reaction rate varies with temperature simultaneously. Impurities in Panzhihua ilmenite decrease the reduction degree. Magnesium and calcium oxide-rich zone is formed preventing complete reduction of Fe^2 . In general, the reaction products are iron, Ti3O5 and carbon.