UGS渣生产工艺研究

【作者】 刘娟；

【导师】 雷霆；

【作者基本信息】 昆明理工大学 ， 有色金属冶金， 2013， 硕士

【摘要】 钛白粉作为目前世界上性能最好的白色颜料,广泛应用于涂料、塑料、造纸等行业,其工业生产方法包括硫酸法和氯化法,其中以沸腾氯化法最具优越性,但是沸腾氯化法对原料中TiO2品位要求高,云南地区钛铁矿经电炉熔炼法生产出的钛渣品位在80%左右,不能满足氯化钛白的原料要求,因此,需对电炉钛渣进一步除杂提纯处理,这对高效利用云南钛资源具有十分重要的现实意义。本文以云南武定某电炉冶炼钛渣为研究对象,通过X衍射、电子显微镜和扫描电镜等现代微观测试手段,对电炉钛渣的化学性质、物相、焙烧机理、酸浸机理进行较深入的分析研究,确定了钛渣钠化焙烧—酸浸除杂的工艺路线,从而提高钛渣中TiO2品位,获得优质的UGS渣(Ultra Grade Slag)。UGS渣即提纯后的高品质钛渣,其杂质含量更少,渣中TiO2含量更高,是氯化法生产钛白粉的优质原料。主要研究内容与结果如下：(1)采用X射线衍射和扫描电镜等分析方法,对钛渣化学性质和物相组成进行了研究,云南武定电炉冶炼钛渣TiO2品位为75.88%,渣中主要杂质为CaO、MgO、Al2O3、 FeO、SiO2, CaO+MgO总含量为1.73%,SiO2和Fe含量较高。主要矿物相为黑钛石固溶体和硅酸盐玻璃体,二者呈镶嵌状分布,Fe、Mg、Al固溶于黑钛石固溶体中,Si、Ca分布在硅酸盐玻璃体中。(2)对钛渣钠化焙烧机理进行研究,钛渣添加Na2C03高温焙烧,黑钛石固溶体中的杂质矿物与Na2CO3发生反应,生成了一系列可溶于酸和水的化合物,通过后续的硫酸酸浸处理,使杂质得以溶出,从而显著提升钛渣中的TiO2品位。(3)对钛渣进行钠化焙烧试验研究,通过正交试验确定最适宜的焙烧条件。将钛渣与碳酸钠按质量比为2：3混合均匀,并磨细至-270～+325目,在975℃下焙烧1.5h,再通过两段硫酸沸腾浸出,可使最终所得的UGS渣TiO2品位提升至93.09%,TiO2回收率达到97%,CaO+MgO总含量为0.157%。(4)通过单因素试验分析钛渣钠化焙烧过程中各影响因素对钛渣除杂提纯效果的研究,研究铝、硅在焙烧过程中的溶除行为,确定适宜的焙烧条件。(5)对钛渣酸浸机理进行研究,并通过正交试验确定最适宜的酸浸条件。通过单因素试验分析钛渣酸浸过程中各影响因素对酸浸效果的影响,研究杂质在酸溶过程中的溶除行为。(6)对钛渣进行机械活化处理,研究不同的活化方式和活化时间对活化效果的影响,研究表明,湿磨处理30min为最佳的活化方式,而且钛渣与Na2C03机械活化处理30min后,能强化钠化焙烧—酸浸除杂效果,使钛渣与Na2C03反应活化能降低,提高反应速率和钛渣的浸出率,经过机械活化—钠化焙烧—酸浸处理,可获得TiO2品位94.42%、TiO2回收率98.19%、CaO+MgO总含量0.125%的优质UGS渣。(7)对钛渣进行对比性试验研究,试验结果表明,Na2CO3和NaOH的混合添加剂比单—添加Na2C03和NaOH效果更为理想,且不是NaOH的加入量越多效果越好,而是以NaOH和Na2C03之比为1：19时所得UGS渣中TiO2品位和回收率最高,分别为95.13%和97.83%,CaO+MgO总含量为0.135%。本论文所提出的机械活化—钠化焙烧—酸浸工艺技术路线是制备优质UGS渣的新工艺,能够很好地去除渣中杂质,从而提高TiO2品位,为氯化法钛白粉生产的优质原料开辟了一种新的途径,为工业上用钛渣制备富钛料提供了理论基础。更多还原

【Abstract】 Nowadays, Titanium dioxide is the best-quality pigment in the world, widely used in coatings, plastic, paper and other industries. The industrial production of Titanium dioxide include sulphate process and chloride process, boiling chloride process is most superiority, However, the demand of raw material’s TiO2is high. The grade of Yunnan titanium slag produced by electric furnace smelting is about75%, which can not be used directly for production of titanium dioxide by chlorination process. Therefore, we should further purify titanium slag, the efficient use of titanium resources in Yunnan province has very important practical significance.In this work, the titanium slag from wuding yunnan province was taken as research project, made analysis the chemical properties, phase composition of titanium slag, roasting and acid leaching mechanism by X-ray diffraction, electron microscopy, scanning electron microscopy and other modern microscopic test. Determined the sodium roasting and acid leaching process for the removal of impurity, so as to improve the grade of TiO2, access to high quality titanium slag(ultra grade slag).Ultra grade slag is high quality titanium slag after the purification, with less impurity content and more TiO2content, which is the high quality raw material for chloride process.The main research contents and results were as follows:(1) The chemical properties and phase composition of titanium slag were studied by XRD and SEM, TiO2content was75.88%, the main impurities were CaO, MgO, Al2O3, FeO and SiO2, CaO+MgO content was1.73%. The main mineral phase were anosovite solid solution and silicate minerals with mosaic structure, Fe, Mg, Al dissolved in anosovite solid solution and Si, Ca distributed in silicate minerals.(2) The study of sodium roasting mechanism showed that adding Na2CO3could make impurity minerals in the anosovite solid solution and Na2CO3react to generate a series of compounds in high temperature, which could be soluble in acid or water, so as to promote the grade of TiO2.(3) Sodium roasting study showed that, Na2CO3and titanium slag were mixed as mass ratio of2:3and ground to-270～+325mesh, roasted at975℃for1.5h, the roasted product was leached by two periods sulphuric acid, the ultra grade slag with93.09%TiO2content and97%recovery and0.157%CaO+MgO content was obtained.(4) How the factors influenced the purification of titanium slag in sodium roasting process was learned by single factor experiment and analysised the purification of Al and Si, determined the best process conditions.(5) Acid leaching mechanism was studied and the best acid leaching condition was determined by orthogonal experiment. How the factors influenced the purification of titanium slag in acid leaching process was learned by single factor experiment and analysised the purification of impurities.(6) When mechanical activating, different activation methods and time for the titanium slag were studied, The studies showed that wet milling for30minutes was the best way of activation. Titanium slag and Na2CO3were mechanical activated for30minutes could reinforce the effect of removing impurities, made the reaction energy lower, and increased the reaction rate and the leaching rate, after mechanical activation-sodium roasting-acid leaching process, the ultra grade slag with94.42%TiO2content and98.19%recovery and0.125%CaO+MgO content was obtained.(7) Comparative experiments showed that the effect of Na2CO3and NaOH mixed adding was better than single adding Na2CO3and NaOH, However, the addition of NaOH was not the more the better, the mass ration of NaOH and Na2CO3was1:19could gain the ultra grade slag in which the TiO2content and recovery was the highest,95.13%and97.83%respectively, CaO+MgO content was0.135%.In this paper, based on the theories of mechanical activation-sodium roasting-acid leaching, a new technology of producing ultra grade slag has been put forward. This technology could remove impurities from titanium slag effectively, improved the grade of TiO2, opened up a new technology for the raw material of chloride process, made a reference for the industrial production of rich-titanium material made by titanium slag.更多还原