本文關(guān)鍵詞： 鋰輝石 工藝礦物學(xué) 晶型轉(zhuǎn)化 堿焙燒法 提鋰　出處：《成都理工大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：四川某地擁有豐富的鋰礦資源,尤以鋰輝石礦為優(yōu)勢礦種,在全國占有非常重要的地位。四川某鋰輝石礦是目前世界上最好的固體鋰礦,品位富,Li2O平均達1.28%,屬富礦品級。由于當(dāng)前關(guān)于該地鋰輝石礦的研究較少,缺乏利用現(xiàn)代測試技術(shù)研究該礦的工藝礦物學(xué)特征。因此,課題在分析四川某鋰輝石礦的工藝礦物學(xué)特征基礎(chǔ)上,進行鋰輝石的堿焙燒法提鋰工藝研究,為合理利用四川某鋰輝石礦提供一定的參考數(shù)據(jù)。本文采用手標本、薄片觀察、X射線衍射(XRD)、傅里葉紅外光譜(FT-IR)、X射線熒光光譜(XRF)和電感耦合等離子體發(fā)射光譜(ICP-OES)等測試方法分析四川某鋰輝石礦的工藝礦物學(xué)特征,在此基礎(chǔ)上以手選鋰輝石單礦為原料,對其轉(zhuǎn)型焙燒條件和堿焙燒法提鋰工藝進行探究,得出以下結(jié)論:(1)鋰輝石礦的主要化學(xué)成分為SiO2、Al2O3、Na2O和K2O,且稀有元素Li、Be、Rb、Cs、Nb、Ta和Sn等含量豐富,Li2O和Rb2O的含量較高,平均品位分別為1.5980%和0.1265%,均達到了工業(yè)品位的要求,具獨立開發(fā)利用價值。該鋰輝石礦主要由鋰輝石、石英、白云母和長石等礦物組成,其含量分別為22.77%、14.69%、13.90%和48.64%。其中,鋰輝石以長柱狀和板狀形式產(chǎn)出,顏色呈淺綠色,并與石英、白云母、微斜長石和鈉長石共生。鋰元素主要賦存于鋰輝石、石英、白云母和長石,Li2O含量分別為7.5855%、0.0418%、0.3843%和0.1667%。銣元素主要賦存在白云母、長石和鋰輝石中,Rb2O的含量分別為0.4016%、0.2715%和0.0044%。(2)探究焙燒溫度和保溫時間對鋰輝石晶型轉(zhuǎn)化焙燒的影響,確定適宜的焙燒溫度為1100℃,保溫時間為3 h。先預(yù)燒后高溫處理的升溫方式,可以使?-鋰輝石完全轉(zhuǎn)化為β-鋰輝石,同時降低了高溫條件下的處理時間。降溫方式的不同對鋰輝石的轉(zhuǎn)型有一定程度的影響,隨爐冷卻較自然冷卻而言,可適當(dāng)延長轉(zhuǎn)型焙燒的作用時間,在一定程度上降低其焙燒溫度或焙燒時間。(3)考察β-鋰輝石與Na2CO3的堿焙燒法提鋰工藝,當(dāng)焙燒溫度為800℃,保溫時間為3 h,β-LiAl Si2O6與Na2CO3摩爾比為1:2.2時,β-鋰輝石中的Li充分轉(zhuǎn)化為可溶性鋰鹽Li4SiO4。在該焙燒體系中,助燒劑NaCl的引入,可以使焙燒溫度從800℃降至650℃,此時,β-鋰輝石中的Li直接生成易溶性鋰鹽Li2CO3,簡化了其提鋰步驟,并節(jié)省了一定的焙燒能耗。(4)?-鋰輝石與Na2CO3直接焙燒實驗結(jié)果表明,?-鋰輝石在800℃溫度下與Na2CO3反應(yīng)困難,難以生成可溶性鋰鹽。而在添加助燒劑NaCl后,兩者可在較低溫度下(640℃)發(fā)生反應(yīng)生成Li2CO3,由此達到提鋰目的。(5)采用β-鋰輝石與純堿進行堿焙燒法提取Li2CO3,在未添加助燒劑和添加助燒劑NaCl的實驗中,鋰的回收率分別為78.67%和68.67%。但相較于目前工業(yè)上的提鋰工藝而言,其回收率偏低。因此,該法的相關(guān)工藝參數(shù)還有待優(yōu)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，

本文編號：1556245