中南大学学报（自然科学版）2023，Vol.54Issue(11)：4228-4237,10.DOI:10.11817/j.issn.1672-7207.2023.11.002
超声辅助隐晶质石墨酸浸动力学及强化机制分析
Analysis of kinetics and strengthening mechanism of ultrasound-assisted acid leaching of cryptocrystalline graphite
摘要
Abstract
To solve the problems of low impurity removal rate and long leaching time in the acid-leaching process of cryptocrystalline graphite,an ultrasonic-assisted method was proposed to enhance the acid-leaching process.Firstly,the optimization of the factors for conventional acid leaching tests was carried out.Secondly,the kinetic parameters of conventional and the kinetic parameters of conventional and ultrasonic acid-leaching processes were calculated.Finally,the fugitive state of impurity minerals in an ultrasonic-enhanced acid leaching process was analyzed by laser particle size meter,X-ray diffraction(XRD),scanning electron microscopy-energy spectroscopy(SEM-EDS),X-ray fluorescence spectroscopy(XRF),transmission electron microscopy-energy spectroscopy(TEM-EDS)and other testing means.The results show that the optimal impurity removal rate of acid leaching is increased to approximately 50%with the presence of ultrasound under optimal conditions of 8 mol/L hydrochloric acid concentration,0.1 g/mL solid-liquid ratio,343 K acid leaching temperature,60 min acid leaching time and 300 W ultrasonic power.The acid-leaching processes under conventional and ultrasonic conditions are in accordance with the Johnson-Mehl-AxTami(JMA)model.The conventional leaching process is controlled by diffusion,while the ultrasonic leaching process changes from diffusion control to mixing control with the increase of temperature.The enhancement of the acid-leaching reaction rate by ultrasound is mainly reflected in the significant increase of the finger front factor.The conventional acid leaching method only removes a part of minerals containing calcium,magnesium,and iron,and ultrasound through the destruction of the graphite surface.Ultrasound improves the removal efficiency of impurity minerals by destroying the inert layer formed on the graphite surface,promoting particle fragmentation,and generating oxidation radicals.关键词
隐晶质石墨/超声波/酸浸除杂/浸出动力学/强化机理Key words
aphanitic graphite ore/ultrasound/HCl leaching impurity removal/leaching kinetics/enhancement mechanism分类
通用工业技术引用本文复制引用
卜祥宁,童正,倪梦茜,任玺冰,陈昱冉,王立强,谢广元..超声辅助隐晶质石墨酸浸动力学及强化机制分析[J].中南大学学报（自然科学版）,2023,54(11):4228-4237,10.基金项目
国家自然科学基金资助项目(52204296) （52204296）
中国博士后科学基金资助项目(2022M722872) （2022M722872）
江苏省研究生科研与实践创新计划项目(SJCX23_1299) （SJCX23_1299）
中国矿业大学研究生创新计划项目(2023WLJCRCZL076)(Project(52204296)supported by the National Natural Science Foundation of China （2023WLJCRCZL076）
Project(2022M722872)supported by the Postdoctoral Science Foundation of China （2022M722872）
Project(SJCX23_1299)supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province （SJCX23_1299）
Project(2023WLJCRCZL076)supported by the Graduate Innovation Program of China University of Mining and Technology) （2023WLJCRCZL076）
