Abstract
The solution behavior, including solubility, reactivity and sedimentation, of ZnO and ZnS in a Na2CO3−NaCl molten salt used for Sb smelting was investigated in the temperature range of 700-1000 ºC. The saturated amount of dissolved ZnO in the molten salt remained constant at 0.02% and was unaffected by temperature; additionally, ZnO did not react with the molten salt. In contrast, the saturated amount of dissolved ZnS in the eutectic molten salt increased with increasing temperature, and the content of ZnS was 0.53% at 1000 ºC. In addition, ZnS reacted with Na2CO3 above 900 ºC to give ZnO. The sedimentation rates of these three species in the molten salt followed the order of Sb>ZnS>ZnO. It was thus concluded that ZnO is an appropriate sulfur-fixing agent for low-temperature Sb smelting in a Na2CO3−NaCl molten medium, and that the optimal smelting temperature is below 900 ºC.
Similar content being viewed by others
References
CHEN G Z, FRAY D F, FARTHING T W. Direct electrochemical reduction of titanium dioxide to titanium in molten calcium chloride [J]. Nature, 2000, 407(6802): 361–364.
CHEN Z Y, ZHU W, ZHU H L, ZHANG J L, LI Q F. Electrochemical performances of LiFePO4/C composites prepared by molten salt method [J]. Transactions of Nonferrous Metals Society of China, 2010, 20(5): 809–813.
GUO C P, LI C G, DU Z M. Thermodynamic optimization of the NaCl-PrCl3 system and the LiCl-NaCl-PrCl3 system [J]. Thermochimica Acta, 2012, 540(7): 85–90.
ZHOU D, ZHAO C Y, TIAN Y. Review on thermal energy storage with phase change (PCMS) in building applications [J]. Applied Energy, 2012, 92(4): 593–605.
ZHAO C Y, WU Z G. Thermal property characterization of a low melting-temperature ternary nitrate salt mixture for thermal energy storage system [J]. Solar Energy Materials and Solar Cells, 2011, 96(12): 3341–3346.
FUJIWARA S, INABA M, TASAKA A. New molten salt systems for high temperature molten salt batteries: Ternary and quaternary molten salt systems based on LiF-LiCl; LiF-LiBr, and LiCl-LiBr [J]. Journal of Power Sources, 2011, 196(8): 4012–4018.
BAO M, WANG Z W, GAO B L, SHI Z N, HU X W, YU J Y. Electrical conductivity of NaF-AlF3-CaF2-Al2O3-ZrO2 molten salts [J]. Transactions of Nonferrous Metals of China, 2013, 23(12): 3788–3792.
IWASAWA K, MAEDA M. Phase diagram study for the alkali metal-oxychloride system [J]. Metallurgy and Materials Transaction B-Process Metallurgy and Materials Processing Science, 2000, 31B(8): 795–799.
JUN Y, KATSUNARI O, KOICHI A. Thermodynamic assessment of the KCl-K2CO3-NaCl-Na2CO3 system [J]. Calphad-Computer Coupling of Phase Diagrams and Thermochemistry, 2007, 31(2): 155–163.
YAOKAWA J, MIURA D, ANZAI K, YAMADA Y, YOSHII H. Strength of salt core composed of alkali carbonate and alkali chloride mixture made by casting technique [J]. Materials Transaction, 2007, 48(5): 1034–1041.
QIAN J G, ZHAO T. Electrodeposition of Ir on platinum in NaCl-KCl molten salt [J]. Transactions of Nonferrous Metals Society of China, 2012, 22(11): 2855–2862.
LV W Y, ZENG C L. Preparation of cohesive graphite films by electroreduction of CO3 2- in molten Na2CO3-NaCl [J]. Surface and Coatings Technology, 2012, 206(219-220): 4287–4292.
IWASAWA K, YAMAGUCHI S, MAEDA M. Phase relation and thermodynamic properties of NaCl-Na2CO3 system as a basic system for secondary fly ash in incineration processes of municipal wastes [J]. Materials Transaction, 2001, 42(12): 2480–2486.
YANG J G, HE D W, TANG C B, CHEN Y M, SUN Y H. Thermodynamics calculation and experimental study on separation of bismuth from a bismuth glance concentrate through a low-temperature molten salt smelting process [J]. Metallurgy and Materials Transaction B-Process Metallurgy and Materials Processing Science, 2011, 42(4): 730–737.
LIU Jing-xin, GUO Xue-yi, LIU Yang. Fractal leaching kinetics of alkaline smelting product with metal enrichment from waste printed circuit boards [J]. The Chinese Journal of Nonferrous Metals, 2015, 25(2): 545–552. (in Chinese)
YE L G, TANG C B, TANG M T, YANG J G, CHEN Y M, YANG S H, HE J. Separation antimony from stibnite concentrate through a low temperature smelting [J]. Journal of Central South University (Science and Technology), 2012, 43(9): 3338–3343. (in Chinese)
YE L G, TANG C B, CHEN Y M, YANG S H, YANG J G, ZHANG W H. One-step extraction of antimony from low-grade stibnite in sodium carbonate-sodium chloride binary molten salt [J]. Journal of Cleaner Production, 2015, 93: 134–139.
CHEN Y M, YE L G, TANG C B, YANG S H, TANG M T, ZHANG W H. Solubility of Sb in binary Na2CO3-NaCl molten salt [J]. Transactions of Nonferrous Metals Society of China, 2015, 25(9): 3146–3151.
LIDE D R, HAYNES W M. CRC Handbook of chemistry and physics (90th Edition) [M]. Floride: CRC Press Inc, 2010: 444–498.
YE L G, TANG C B, CHEN Y M, YANG S H, TANG M T. Thermal physical properties and stability of the eutectic composition in a Na2CO3-NaCl binary system [J]. Thermochimica Acta, 2014, 596(10): 14–20.
Author information
Authors and Affiliations
Corresponding author
Additional information
Foundation item: Projects(51104128, 51234009) supported by the National Natural Science Foundation of China
Rights and permissions
About this article
Cite this article
Ye, Lg., Hu, Yj., Xia, Zm. et al. Solution behavior of ZnS and ZnO in eutectic Na2CO3−NaCl molten salt used for Sb smelting. J. Cent. South Univ. 24, 1269–1274 (2017). https://doi.org/10.1007/s11771-017-3531-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11771-017-3531-8