Potassium recovery from muscovite using NaCl-roasting followed by H_(2)SO_(4)-leaching  

氯化钠焙烧-硫酸浸出从白云母矿中提取钾

作　　者：Sandeep Kumar JENA Baijayantimala MOHANTY Geetikamayee PADHY Jogeshwara SAHU Sapan Kumar KANDI Sandeep Kumar JENA;Baijayantimala MOHANTY;Geetikamayee PADHY;Jogeshwara SAHU;Sapan Kumar KANDI(CSIR-Institute of Minerals and Materials Technology,Bhubaneswar,Odisha-751013,India)

机构地区：[1]CSIR-Institute of Minerals and Materials Technology,Bhubaneswar,Odisha-751013,India

出　　处：《Journal of Central South University》2022年第6期1881-1894,共14页中南大学学报（英文版）

摘　　要：The present study aims at the recovery of potassium from muscovite mica(which contains K_(2)O;~10 wt%)using NaCl-roasting coupled with H_(2)SO_(4)-leaching process.The preliminary acid leaching studies applying different mineral acids resulted in a potassium recovery of 8%−18%.The optimum leaching conditions for the maximum recovery were 4 mol/L H_(2)SO_(4),60 min leaching time and liquid-solid ratio 4 mL/g at 90℃.However,the roasting of muscovite with additive NaCl(muscovite:NaCl mass ratio of 1:1.00,900℃,45 min)followed by H_(2)SO_(4)-leaching(95℃,60 min)extracted potassium to the tune of 98%.Under similar roasting conditions,the H_(2)O-leaching process extracted only 60%of potassium.The effects of various roasting and leaching parameters such as temperature,time,NaCl concentration,acid concentration,liquid-solid ratio on potassium extraction were evaluated.The appearance of the sylvite(KCl)mineral phase in the NaCl-roasted muscovite and its disappearance in the acid/water leached residue confirmed the physical and chemical distortions of the muscovite crystal structure.The possible mechanism of potassium release from the complex muscovite structure was elucidated based on available literature substantiated by characterizations using X-ray diffraction(XRD)and scanning electron microscopy with energy dispersive X-rays spectroscopy(SEM-EDX).本研究旨在采用氯化钠焙烧与-硫酸浸取结合的浸出工艺,从含约10 wt%氧化钾的白云母中提取钾。当仅用硫酸浸出从白云母矿中提取钾时,钾的提取率为8%~18%。获得最大提取率的最佳浸出条件为4 mol/L硫酸,浸出时间为60 min,液固比为4 m L/g。然而,先添加氯化钠焙烧(白云母矿与氯化钠的质量比为1:1,焙烧为900℃,焙烧时间为45 min),然后再用硫酸浸出(浸出温度为95℃,浸出时间为60 min),钾提取率达到98%。在类似的焙烧条件下,仅用硫酸浸出从白云母矿中提取钾,钾提取率仅为60%。分析了温度、时间、氯化钠浓度、硫酸浓度、液固比等焙烧和浸出参数对钾提取的影响。与氯化钠焙烧后白云母中出现的氯化钾物相在硫酸浸出后的残留物中消失,证实了白云母矿石晶体结构的物理和化学变化。依据现有文献,结合X射线衍射和带有能量色散X射线光谱的扫描电子显微镜表征结果,阐明了白云母矿结构中释放钾的可能机制。

关 键 词：MUSCOVITE ROASTING acid leaching potassium recovery SYLVITE 

分 类 号：TF826.1[冶金工程—有色金属冶金]