云南钛精矿制备高品质人造金红石技术研究
发布时间：2019-05-15 18:34
【摘要】：近年来,氯化法钛白越来越受到国家的重视,但是我国在氯化法钛白生产中仍存在无法获得稳定的高品质人造金红石原料的问题。原料问题已经成为我国钛工业发展的瓶颈,要摆脱对进口矿的依赖,必须研究出适合我国钛铁矿为原料制备高品质人造金红石的生产技术。盐酸浸出法不仅可以有效的去除钛铁矿中的铁钙镁等杂质,获得高品质的人造金红石,而且盐酸可以循环使用,被世界各大生产厂家所采用。本论文围绕盐酸浸出云南钛精矿制备人造金红石进行了大量的理论分析和试验研究。云南钛精矿原矿直接浸出时反应活性差,预氧化和预还原焙烧均可提高反应活性,但预还原矿和原矿浸出的粉化率均较高(75μm下的产品占30~40%),而预氧化矿浸出的粉化率较低(75μm下的产品少于5%)。采用盐酸常压浸出工艺时,所需盐酸浓度较高(26%),浸出时间较长(一般至少需要7h),浸出产品TiO2品位低于91%。采用加压浸出工艺时,可以降低盐酸浓度,缩短浸出时间。实验表明,采用一段加压浸出工艺时,使用20%的盐酸,浸出产品TiO2品位稳定在92%左右,但液固比较大(8:1),并且浸出滤液中酸浓度较高(12~13%),而铁离子浓度较低(44g/L),不利于废酸回收。采用盐酸两段加压浸出工艺,第一段利用第二段浸出液浸出,第二段采用20%的新酸,两段液固比均为5:1、浸出温度140℃、浸出压力0.175MPa、每段浸出时间4h,既可以获得高品位的人造金红石(TiO2品位可达93%),又可以降低液固比,降低浸出母液中的酸浓度(7%左右)和提高浸出母液中的铁离子浓度(75g/L)。盐酸浸出云南钛精矿原矿和氧化矿均受内扩散控制,原矿和氧化矿常压浸出活化能分别为为62.45kJ/mol和55.21kJ/mol,氧化矿加压浸出活化能为24.64kJ/mol。针对盐酸浸出云南钛精矿产生的粉化现象,通过对原料和浸出产物的分析,以及钛的溶解与水解规律的总结,提出了一种盐酸浸出云南钛精矿粉化控制机制。在浸出方式一定的条件下,降低粉化主要采用降低均相成核、增大异相形核水解的方法,使得矿粒不易破碎,降低以细小矿粒为异相核心的水解是降低粉化的关键。原矿浸出时,反应活性差,水解开始时间长。还原矿浸出时,大量的晶体和小颗粒矿被粉碎,水解很大一部分发生在这种小颗粒矿上,造成浸出产物细化。预氧化焙烧后的钛精矿矿粒强度较高,大量金红石微晶的出现降低了异相形核水解的自由能,浸出时以金红石微晶为核心进行水解,水解粒子呈团状逐渐向矿粒内部生长,抗粉碎强度较高,使得浸出产物粒度较大。
[Abstract]:In recent years, chlorination titanium dioxide has been paid more and more attention by the state, but there is still a problem that stable high quality artificial rutile raw materials can not be obtained in the production of chlorination titanium dioxide in our country. The problem of raw materials has become the bottleneck of the development of titanium industry in China. In order to get rid of the dependence on imported minerals, it is necessary to develop a production technology suitable for the preparation of high quality artificial rutile from ilmenite in China. Hydrochloric acid leaching method can not only effectively remove iron, calcium, magnesium and other impurities from ilmenite, but also obtain high quality artificial rutile, and hydrochloric acid can be recycled and adopted by major manufacturers in the world. In this paper, a large number of theoretical analysis and experimental studies have been carried out on the preparation of artificial rutile from Yunnan titanium concentrate by hydrochloric acid leaching. The reaction activity of Yunnan titanium concentrate is poor when the raw ore is directly leached, and both pre-oxidation and pre-reduction roasting can improve the reaction activity, but the pulverized rate of pre-reduction ore and raw ore leaching is higher (the product at 75 渭 m accounts for 30 鈮，
本文编号：2477710
[Abstract]:In recent years, chlorination titanium dioxide has been paid more and more attention by the state, but there is still a problem that stable high quality artificial rutile raw materials can not be obtained in the production of chlorination titanium dioxide in our country. The problem of raw materials has become the bottleneck of the development of titanium industry in China. In order to get rid of the dependence on imported minerals, it is necessary to develop a production technology suitable for the preparation of high quality artificial rutile from ilmenite in China. Hydrochloric acid leaching method can not only effectively remove iron, calcium, magnesium and other impurities from ilmenite, but also obtain high quality artificial rutile, and hydrochloric acid can be recycled and adopted by major manufacturers in the world. In this paper, a large number of theoretical analysis and experimental studies have been carried out on the preparation of artificial rutile from Yunnan titanium concentrate by hydrochloric acid leaching. The reaction activity of Yunnan titanium concentrate is poor when the raw ore is directly leached, and both pre-oxidation and pre-reduction roasting can improve the reaction activity, but the pulverized rate of pre-reduction ore and raw ore leaching is higher (the product at 75 渭 m accounts for 30 鈮，
本文编号：2477710
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