四川某锂辉石矿工艺矿物学及其提锂工艺研究

发布时间：2018-03-02 11:03

  本文关键词： 锂辉石 工艺矿物学 晶型转化 碱焙烧法 提锂　出处：《成都理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：四川某地拥有丰富的锂矿资源,尤以锂辉石矿为优势矿种,在全国占有非常重要的地位。四川某锂辉石矿是目前世界上最好的固体锂矿,品位富,Li2O平均达1.28%,属富矿品级。由于当前关于该地锂辉石矿的研究较少,缺乏利用现代测试技术研究该矿的工艺矿物学特征。因此,课题在分析四川某锂辉石矿的工艺矿物学特征基础上,进行锂辉石的碱焙烧法提锂工艺研究,为合理利用四川某锂辉石矿提供一定的参考数据。本文采用手标本、薄片观察、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、X射线荧光光谱(XRF)和电感耦合等离子体发射光谱(ICP-OES)等测试方法分析四川某锂辉石矿的工艺矿物学特征,在此基础上以手选锂辉石单矿为原料,对其转型焙烧条件和碱焙烧法提锂工艺进行探究,得出以下结论:(1)锂辉石矿的主要化学成分为SiO2、Al2O3、Na2O和K2O,且稀有元素Li、Be、Rb、Cs、Nb、Ta和Sn等含量丰富,Li2O和Rb2O的含量较高,平均品位分别为1.5980%和0.1265%,均达到了工业品位的要求,具独立开发利用价值。该锂辉石矿主要由锂辉石、石英、白云母和长石等矿物组成,其含量分别为22.77%、14.69%、13.90%和48.64%。其中,锂辉石以长柱状和板状形式产出,颜色呈浅绿色,并与石英、白云母、微斜长石和钠长石共生。锂元素主要赋存于锂辉石、石英、白云母和长石,Li2O含量分别为7.5855%、0.0418%、0.3843%和0.1667%。铷元素主要赋存在白云母、长石和锂辉石中,Rb2O的含量分别为0.4016%、0.2715%和0.0044%。(2)探究焙烧温度和保温时间对锂辉石晶型转化焙烧的影响,确定适宜的焙烧温度为1100℃,保温时间为3 h。先预烧后高温处理的升温方式,可以使?-锂辉石完全转化为β-锂辉石,同时降低了高温条件下的处理时间。降温方式的不同对锂辉石的转型有一定程度的影响,随炉冷却较自然冷却而言,可适当延长转型焙烧的作用时间,在一定程度上降低其焙烧温度或焙烧时间。(3)考察β-锂辉石与Na2CO3的碱焙烧法提锂工艺,当焙烧温度为800℃,保温时间为3 h,β-LiAl Si2O6与Na2CO3摩尔比为1:2.2时,β-锂辉石中的Li充分转化为可溶性锂盐Li4SiO4。在该焙烧体系中,助烧剂NaCl的引入,可以使焙烧温度从800℃降至650℃,此时,β-锂辉石中的Li直接生成易溶性锂盐Li2CO3,简化了其提锂步骤,并节省了一定的焙烧能耗。(4)?-锂辉石与Na2CO3直接焙烧实验结果表明,?-锂辉石在800℃温度下与Na2CO3反应困难,难以生成可溶性锂盐。而在添加助烧剂NaCl后,两者可在较低温度下(640℃)发生反应生成Li2CO3,由此达到提锂目的。(5)采用β-锂辉石与纯碱进行碱焙烧法提取Li2CO3,在未添加助烧剂和添加助烧剂NaCl的实验中,锂的回收率分别为78.67%和68.67%。但相较于目前工业上的提锂工艺而言,其回收率偏低。因此,该法的相关工艺参数还有待优化。
[Abstract]:Sichuan has abundant lithium ore resources, especially spodumene ore, which occupies a very important position in the whole country. At present, a spodumene ore in Sichuan is the best solid lithium ore in the world. The grade of Li _ 2O is 1.28 on average, which belongs to the grade of rich ore. Because there are few researches on the spodumene ore in this area at present, there is no use of modern testing technology to study the technological mineralogical characteristics of the ore. Based on the analysis of the technological mineralogical characteristics of a spodumene ore in Sichuan Province, this paper studies the alkali roasting process of spodumene to extract lithium, which provides some reference data for the rational utilization of a spodumene ore in Sichuan. The characteristics of technological mineralogy of a spodumene ore in Sichuan Province were analyzed by means of thin slice observation, X-ray diffraction (XRDX), Fourier transform infrared spectroscopy (FT-IR) and inductively coupled plasma emission spectrometry (ICP-OES). On this basis, the conversion roasting conditions and alkali roasting process for lithium extraction from hand-selected spodumene single ore were investigated. The main chemical constituents of the spodumene are Sio _ 2, Al _ 2O _ 3, Na _ 2O and K _ 2O, and the contents of rare elements Lio _ 2O _ 2, Al _ 2O _ 3, Na _ 2O and K _ 2O are very high, and the contents of Li _ 2O, Li _ 2O, Ta and Sn are high, the average grade is 1.5980% and 0.1265, respectively, which meet the requirements of industrial grade. The spodumene is mainly composed of spodumene, quartz, Muscovite and feldspar, the content of which is 22.77714.69g 13.90% and 48.64% respectively. Muscovite, microplagioclase and albite are symbiotic. Lithium is mainly present in spodumene, quartz, Muscovite and feldspar with the contents of 7.585555, 0.0418 and 0.3843% and 0.1667, respectively. Rubidium is mainly found in Muscovite, Muscovite, Muscovite and feldspar. The content of Rb2O in feldspumene and spodumene is 0.40160.2715% and 0.0044.4% respectively. The effects of calcination temperature and holding time on the conversion roasting of spodumene crystal form are investigated. The suitable calcination temperature is 1100 鈩，

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