电炉钛渣制备富钛料试验研究

【作者】 杨艳华；

【导师】 雷霆；

【作者基本信息】 昆明理工大学 ， 冶金物理化学， 2006， 硕士

【摘要】 在分析了国内外电炉冶炼钛渣制备富钛料的基础上，论文研究了一种用电炉钛渣制备富钛料的新方法，通过试验研究，认为含TiO₂品位较低的钛渣经过高压碱浸再采用常压酸浸后可以制备出含TiO₂大于90％的富钛料，满足氯化法生产钛白粉和海绵钛的原料要求。采用化学分析、X射线衍射和扫描电镜等分析方法，对电炉钛渣的相组成进行了研究，查明了钛渣主要由黑钛石固溶体、塔基石固溶体、硅酸盐玻璃体和游离的TiO₂组成。分析了还原剂的配比、熔炼温度和冷却温度对电炉钛渣相组成的影响。研究了电炉熔炼钛渣中的杂质主要是由于电炉熔炼钛精矿时，钛精矿中的杂质不能被还原或不能完全被还原而富集于钛渣中形成的，主要包括在还原熔炼过程中完全转入渣中的杂质，如CaO、MgO、Al₂O₃等和部分被还原的杂质，如SiO₂、MnO和V₂O₅等。提出了电炉钛渣的除杂机理，并通过盐酸常压浸出和硫酸加压浸出试验，验证了主要结论，即无机酸对钛渣相中的大部分Fe、Mg、Mn、V和其他杂质，常规条件下不起反应，硅酸盐玻璃体分布于黑钛石的内部，直接采用酸浸法除杂，要将钛渣中TiO₂的品位提高到大于90％是不可行的。通过NaOH高压碱浸、Na₂CO₃高压浸出和NaOH常压浸出后的三种钛渣分别采用常压酸浸，试验表明，Na₂CO₃高压浸出和NaOH常压浸出渣不能制备出TiO₂含量大于90％的富钛料。NaOH高压浸渣采用高压和常压酸浸试验表明，高压酸浸使得钛渣的TiO₂含量降低，TiO₂回收率也降低，选择常压酸浸是合理的。在温度120℃、压力0.2MPa、保压时间2h、NaOH浓度60～100（g／l）条件下，通过高压碱浸能破坏钛渣的高温固溶体结构，并选择性地除去部分SiO₂和Al₂O₃等杂质，再对碱浸渣在温度大于80℃、时间2h、酸浓度25g／l条件下，用常压酸浸并洗涤，可将含TiO₂80～87（％）的电炉钛渣制成含TiO₂大于90％的富钛料。更多还原

【Abstract】 On the basis of analyzing the situation of preparing rich titanium product from electro-titanium slag at home and abroad, in this dissertation, a new method of preparing rich titanium product has been studied. Via experimental investigation, rich titanium product with TiO₂>90% can be prepared from the slag by acid leaching which has leached with sodium hydroxide at high pressure. The prepared rich titanium product was suitable feedstock for chloride pigment and sponge titanium.By using methods of chemical analysis , X-ray diffraction, scanning electron microscope and so on, the X-ray diffraction figures, crystal phases and the phase compositions are obtained, phase compositions are analyzed, the phase compositions including TiO₂, Ti₃O₅, （Mg,Fe）Ti₂O₅, Al₄Ti₂SiO₁₂ etc. The effects of reductant ratio , smelting temperature and cooling temperature on phase compositions of titanium slag are analyzed. The main impurities of electro-titanium Slag are studied, these impurities were formed from melting titanium concentrates. In the process of melting titanium concentrates, some impurities were completely switch to titanium slag such as CaO, MgO, Al₂O₃ etc, some impurities, which can not be completely deoxidized, were partially switch to titanium slag such as SiO₂, MnO, V₂O₅ etc. The removal impurities mechanism from electro-titanium slag was put forward, then the main conclusion was verified by the experiments of leaching by hydrochloric acid at normal presure and sulfuric acid at high pressure. Namely, the great mass of Fe, Mg, Mn, V and other impurities have inertness toward the action of mineral acids, glass silicate phase is present in the form of inclusions, attachments and veins inside the pseudobrookite, it’s not viable to raise the rade of TiO₂ to more than 90% only by the acid leaching to remove the impurities directly.By high pressure NaOH leaching, high pressure Na₂CO₃ leaching, andnormal pressure NaOH leaching, then these slags were separately leached by normal pressure, it is proved that the slag which was leached by high pressure Na₂CO₃ and normal pressure NaOH can not be prepared rich titanium product with TiO₂>90%. The slag leached by high pressure NaOH was leached with high and normal pressure acid, it is proved that high pressure acid leaching caused the decrease of TiO₂ and rate of recovery, it is reasonable to choose normal acid leaching.Under the condition of temperature 120°C, pressure 0.2MPa, keeping pressure time 2h, sodium hydroxide concentration 60¹00 （g/l）, high pressure sodium hydroxide leaching can destroy the sosloid structure and selectively remove SiO₂ and Al₂O₃ in the Electro-titanium slag, Then rich titanium product of TiO₂>90% was prepared from electro-titanium slag of TiO₂80⁸7（%）by using sulfuric acid leaching and washing, on the condition that temperature>80°C, time 2h, acid concentration 25g/l.更多还原