A Kinetic Study of Indium Leaching from Indium-Bearing Zinc Ferrite Under Microwave Heating
- PDF / 600,878 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 35 Downloads / 206 Views
TION
INDIUM is an important strategic metal due to its unique physical and chemical properties including high ductility, strong conductibility, low melting point, relative chemical stability, etc.[1,2] Indium is widely used to make liquid crystal displays, semiconductors, low-temperature solders, infrared photodetectors, solar cells, high-speed transistors, etc.[3–5] In recent years, with the extensive demand of indium, the high-grade indium ores have been gradually exhausted, and the extraction of indium from the low-grade indium materials is becoming more and more important. Indium is most commonly found in zincbearing materials such as solid solution of sphalerite or marmatite, and China is abundant in natural materials of indium mostly in zinc-bearing minerals. Most zinc refining plants operate a roasting-leaching-electrowinning process, and zinc ferrite (ZnFe2O4) is produced upon complete roasting at 1223 K (950 C) in this roasting process. Meanwhile, indium could occupy the Fe lattice sites, and then accumulates in ZnFe2O4, resulting in the formation of indium-bearing zinc ferrite (IBZF or LINYE ZHANG, Ph.D. Candidate, JIAMEI MO, Master Candidate, XUANHAI LI, Professor, and LIUPING PAN and XINYUAN LIANG, Associate Professors, are with the School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, P.R. China. Contact e-mail: [email protected] GUANGTAO WEI, formerly Professor with the School of Chemistry and Chemical Engineering, Guangxi University, is now Visiting Scholar with the Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada. Contact e-mail: [email protected] Manuscript submitted March 23, 2013. Article published online October 17, 2013. METALLURGICAL AND MATERIALS TRANSACTIONS B
ZnFe(2m)InmO4).[6] IBZF, like zinc ferrite, has excellent chemical stability; IBZF is insoluble in most acidic, alkaline, and chelating media under mild conditions.[7,8] As a result, the indium extraction ratio is quite low in the hydrometallurgical extraction process with the conventional heating (CH) method, and the environmental pollution caused in this time-consuming and inefficient process is also very serious. With the increasing demand for more environmentally friendly processes in indium extraction, it is necessary to find a new hydrometallurgical extraction method to increase the leaching efficiency of indium under relative mild conditions. Microwave energy is a form of electromagnetic energy, and it can be used in industrial processes for heating and reacting. Microwave heating (MH) has been an interesting alternative for CH systems.[9] Compared with CH, the main advantages of MH are internal and volumetric heating and nonthermal enhancing.[10,11] In addition, the prominent advantages of MH are low processing time; direct, selective heating; and a more controllable heating process.[12] MH has absolute advantages over CH in the mineral extraction of metals such as copper, gold, lead, zinc, nickel, manganese, etc.[13–17] It has been concluded that microwave heatin
Data Loading...
