亚熔盐低温浸取钾长石工艺过程  

Leaching Process of Potassium Feldspar by Sub-Molten Salt at Low Temperature

作　　者：姜炜 罗孟杰[1] 刘程琳[1] 李平[1] 于建国[1] JIANG Wei;LUO Mengjie;LIU Chenglin;LI Ping;YU Jianguo(National Engineering Research Center for Integrated Utilization of Salt Lake Resources,State Key Laboratory ofChemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学国家盐湖资源综合利用工程技术研究中心化学工程联合国家重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2019年第2期206-215,共10页Journal of East China University of Science and Technology

基　　金：国家自然科学基金(21776089;U1610102);政府间国际合作项目(2016YFE0132500;2015DFG42220)

摘　　要：采用KOH亚熔盐在常压低温条件下浸取河北灵寿县钾长石粗矿,回收K、Al、Si有价元素,研究浸取温度、碱矿质量比、搅拌速率以及反应时间对钾长石粗矿中K、Al、Si元素浸出率的影响。结果发现:在常压、230℃、碱矿质量比3∶1、搅拌速率500 r/min和反应时间150 min时,KOH亚熔盐能够较好分解钾长石,K、Al、Si元素浸出率分别达到98.3%、96.9%和94.3%。在浸出动力学实验数据基础上,进一步采用未反应收缩核模型计算K、Al、Si的浸出活化能,结果表明表面化学反应为浸出过程的控制步骤。Potassium feldspar crude ore came from Lingshou County,Hebei Province,which mainly contained K2O (w=13.71%),Al2O3 (w=21.51%) and SiO2 (w=61.02%) based on the mineralogical characteristics analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF).To recover valuable elements including K,Al,Si from potassium feldspar crude ore for preparation of high quality products,KOH sub-molten salt method was adopted to decompose potassium feldspar crude ore at low temperature under atmospheric conditions.The effects of leaching temperature,alkali-to-ore mass ratio,stirring rate and leaching time on the leaching rates of K,Al,Si from potassium feldspar crude ore were investigated,respectively.Both thermodynamic analysis and experimental results demonstrated that the concentrated alkali solution (wKOH=89.66%) at sub-molten salt state had a high chemical reaction activity,which could decompose potassium feldspar crude ore at a relatively low temperature,such as 230 ℃.With alkali-to-ore mass ratio of 3∶1,stirring rate of 500 r/min,leaching time of 150 min,the leaching rates of K,Al,Si from potassium feldspar crude ore at 230 ℃ were 98.3%,96.9%and 94.3%,respectively.X-ray diffraction (XRD) spectra of products also demonstrated that potassium feldspar crude ore almost completely decomposed.The unreacted shrinking core model with the surface chemical reaction control was used to predict the leaching kinetics of potassium feldspar crude ore by KOH sub-molten salt at the temperature range of 220.250 ℃.Based on the experimental data of leaching kinetics,the apparent activation energy of K,Al,Si were calculated as 84.2,79.1,78.3 kJ/mol,respectively.

关 键 词：钾长石 氢氧化钾 亚熔盐 低温浸取 

分 类 号：TQ443.5[化学工程—化学肥料工业]