An environmental-friendly process for dissociating toxic substances and recovering valuable components from spent carbon cathode

被引：57
作者：
Yao, Zhen [1 ,2 ]
Zhong, Qifan [1 ,3 ]
Xiao, Jin [1 ,3 ]
Ye, Shengchao [1 ]
Tang, Lei [1 ]
Zhang, Zhenhua [1 ]
机构：
[1] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China
[2] Guizhou Normal Univ, Sch Mat & Architectural Engn, Guiyang 550001, Peoples R China
[3] Cent South Univ, Natl Engn Lab Efficient Utilizat Refractory Nonfe, Changsha 410083, Peoples R China
来源：
JOURNAL OF HAZARDOUS MATERIALS | 2021年 / 404卷
基金：
中国国家自然科学基金;
关键词：
Hazardous solid waste; Spent carbon cathode; Fluorine recovery; Carbonation; ALUMINUM HYDROXYFLUORIDE HYDRATE; THERMAL-DECOMPOSITION; CHEMICAL-REACTIONS; STONE COAL; FLUORIDE; WASTE; PRECIPITATION; WATER; CRYOLITE; METALS;
D O I：
10.1016/j.jhazmat.2020.124120
中图分类号：
X [环境科学、安全科学];
学科分类号：
08 ; 0830 ;
摘要：
Spent carbon cathode (SCC), a hazardous solid waste discharged from the aluminum electrolysis industry, has a serious environmental pollution risk. This study aims to explore an environmental friendly process for dissociating toxic substances and recovering valuable components from SCC. Parameters of molten salt-assisted roasting and water leaching were optimized. A possible dissociation mechanism of toxic substances was proposed. Results showed that 99.12% of cyanide was decomposed and 96.63% of fluoride was leached under optimal conditions. The recovery route of fluoride was designed according to the solution equilibrium chemical calculation and the difference in solubility and particle size between the recovered products. Exhaust gas with a high concentration of CO and CO2 was used for the carbonation of the leaching solution to recover cryolite. Effects of reaction conditions on precipitation mass and phase composition of recovered cryolite were investigated in detail. Characterization results indicated that the crystallinity and particle size of cryolite recovered under optimal conditions were extremely similar to those of commercial products. Finally, NaF and Na2CO3 were separated and recovered via evaporative crystallization combined with selective filtration. This proposed process with circular economy and green chemistry characteristics is expected to recover valuable components while minimizing environmental hazards of SCC.
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页数：15
相关论文
共 61 条
[1]  
[Anonymous], 2020, INT ALUMINIUM I SUST
[2]  
Birry L, 2016, LIGHT MET, P467
[3]   PENETRATION AND CHEMICAL-REACTIONS IN CARBON CATHODES DURING ALUMINUM ELECTROLYSIS .1. LABORATORY EXPERIMENTS [J].
BRILLOIT, P ;
LOSSIUS, LP ;
OYE, HA .
METALLURGICAL TRANSACTIONS B-PROCESS METALLURGY, 1993, 24 (01) :75-89
[4]   X-ray photoelectron spectroscopy study of sodium reactions in carbon cathode blocks of aluminium oxide reduction cells [J].
Brisson, P. -Y. ;
Darmstadt, H. ;
Fafard, M. ;
Adnot, A. ;
Servant, G. ;
Soucy, G. .
CARBON, 2006, 44 (08) :1438-1447
[5]   Phase transformations of vanadium recovery from refractory stone coal by novel NaOH molten roasting and water leaching technology [J].
Cai, Zhenlei ;
Zhang, Yimin .
RSC ADVANCES, 2017, 7 (59) :36917-36922
[6]   Comparative biomonitoring of leachates from hazardous solid waste of two industries using Allium test [J].
Chandra, S ;
Chauhan, LKS ;
Murthy, RC ;
Saxena, PN ;
Pande, PN ;
Gupta, SK .
SCIENCE OF THE TOTAL ENVIRONMENT, 2005, 347 (1-3) :46-52
[7]   A novel process for recovery of iron, titanium, and vanadium from titanomagnetite concentrates: NaOH molten salt roasting and water leaching processes [J].
Chen, Desheng ;
Zhao, Longsheng ;
Liu, Yahui ;
Qi, Tao ;
Wang, Jianchong ;
Wang, Lina .
JOURNAL OF HAZARDOUS MATERIALS, 2013, 244 :588-595
[8]   Comparison of kinetic analysis methods in thermal decomposition of cattle manure by themogravimetric analysis [J].
Chen, Guanyi ;
He, Sirong ;
Cheng, Zhanjun ;
Guan, Yanan ;
Yan, Beibei ;
Ma, Wenchao ;
Leung, Dennis Y. C. .
BIORESOURCE TECHNOLOGY, 2017, 243 :69-77
[9]   Fluoride recovery from spent fluoride etching solution through crystallization of Na3AlF6 (synthetic cryolite) [J].
Chen, Jie-Yuan ;
Lin, Chih-Wei ;
Lin, Po-Han ;
Li, Chi-Wang ;
Liang, Yang-Min ;
Liu, Jhy-Chern ;
Chen, Shiao-Shing .
SEPARATION AND PURIFICATION TECHNOLOGY, 2014, 137 :53-58
[10]   Low-Temperature Molten-Salt-Assisted Recovery of Valuable Metals from Spent Lithium-Ion Batteries [J].
Fan, Ersha ;
Li, Li ;
Lin, Jiao ;
Wu, Jiawei ;
Yang, Jingbo ;
Wu, Feng ;
Chen, Renjie .
ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 2019, 7 (19) :16144-16150
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