A chloridizing roasting process was used to remove copper and sulphur from copper slags in this study. Higher holding temperature and longer residence time were beneficial to the removal of copper and sulphur. Massive 2CaO·SiO2 was produced with O2 velocity and CaCl2 addition amount being increased over a proper value, enclosing the unreacted CaCl2 particles and reducing the decoppering rate. Sulphur was removed effectively through the action of chlorination and direct oxidization. 2FeO·SiO2 was oxidized to Fe3O4 and Fe2O3 in this process, and the chlorination of these two species was difficult to implement, causing low iron losses of approximately 5%. The resulting decoppering rate of 92.21% and slag sulphur content of 0.0363% were obtained at the optimum conditions of holding temperature of 1473 K, residence time of 60 min, CaCl2 addition amount of 0.14 (mass ratio of CaCl2 to the copper slag) and oxygen flow rate of 0.3 L min−1.
AdamC, PeplinskiB, MichaelisM, KleyG, SimonFG.2009. Thermochemical treatment of sewage sludge ashes for phosphorus recovery. Waste Manage. 29:1122–1128. doi: 10.1016/j.wasman.2008.09.011
2.
BourhilaN, ThomasN, PalleauJ, TorresJ, BernardC, MadarR.1995. Thermodynamic and experimental study of Cu-LPCVD by reduction of copper chloride. Appl Surf Sci. 91:175–181. doi: 10.1016/0169-4332(95)00115-8
3.
BrocchiEA, MouraFJ.2008. Chlorination methods applied to recover refractory metals from tin slags. Miner Eng.21:150–156. doi: 10.1016/j.mineng.2007.08.011
4.
ChanCCY, KirkDW.1999. Behaviour of metals under the conditions of roasting MSW incinerator fly ash with chlorinating agents. J Hazard Mater. 64B:75–89.
5.
DongYW, JiangZH, LiangLK, LiZB.2011. Hydrogen permeability of slags containing calcium fluoride. J Cent South Univ Technol. 18:1063–1067. doi: 10.1007/s11771-011-0804-5
6.
FraisslerG, JollerM, BrunnerT, ObernbergerI.2009a. Influence of dry and humid gaseous atmosphere on the thermal decomposition of calcium chloride and its impact on the remove of heavy metals by chlorination. Chem Eng Process: Process Intensification. 48:380–388. doi: 10.1016/j.cep.2008.05.003
7.
FraisslerG, JollerM, MattenbergerH, BrunnerT, ObernbergerI.2009b. Thermodynamic equilibrium calculations concerning the removal of heavy metals from sewage sludge ash by chlorination. Chem Eng Process: Process Intensification. 48:152–164. doi: 10.1016/j.cep.2008.03.009
8.
HanW, QinQW.2009. Recovery of copper and iron from copper slag. Min Metall. 18:9–12. Chinese
9.
HuCQ, ZhangCX, HanXW, YinRY.2008. Sulphur flow analysis for new generation steel manufacturing process. J Iron Steel Res Int. 15:12–15, 37. doi: 10.1016/S1006-706X(08)60136-3
10.
LeeGS, SongYJ.2009. Recycling EAF dust by heat treatment with PVC. Miner Eng. 20:739–746. doi: 10.1016/j.mineng.2007.03.001
11.
LiL, WangH, HuJH.2010. The study of recovering iron by melting reduction from copper slag. 2010 International Conference on Digital Manufacturing & Automation. 2:823–827. doi: 10.1109/ICDMA.2010.395
12.
MattenbergerH, FraisslerG, BrunnerT, HerkP, HermannL, ObernbergerI.2008. Sewage sludge ash to phosphorus fertiliser: variables influencing heavy metal removal during thermochemical treatment. Waste Manage. 28:2709–2722. doi: 10.1016/j.wasman.2008.01.005
13.
MawejaK, MukongoT, MutomboI.2009. Cleaning of a copper matte smelting slag from a water-jacket furnace by direct reduction of heavy metals. J Hazard Mater. 164:856–862. doi: 10.1016/j.jhazmat.2008.08.107
14.
MiccoGD, BoheAE, PasquevichDM.2007. A thermogravimetric study of copper chlorination. J Alloy Compd. 437:351–359. doi: 10.1016/j.jallcom.2006.08.003
15.
MuravyovMI, FomchenkoNV, UsoltsevAV, VasilyevEA, KondratevaTF.2012. Leaching of copper and zinc from copper converter slag flotation tailings using H2SO4. Hydrometallurgy. 119–120:40–46. doi: 10.1016/j.hydromet.2012.03.001
16.
NowakB, PesslA, AschenbrennerP, SzentannaiP, MattenbergerH, RechbergerH, HermannL, WinterF.2010. Heavy metal removal from municipal solid waste fly ash by chlorination and thermal treatment. J Hazard Mater. 179:323–331. doi: 10.1016/j.jhazmat.2010.03.008
17.
PicklesCA.2009. Thermodynamic analysis of the selective chlorination of electric arc furnace dust. J Hazard Mater. 166:1030–1042. doi: 10.1016/j.jhazmat.2008.11.110
18.
WangJJ, GuoSX, ZhouL, LiQ.2009. Slag for decopperization and sulphur control in molten steel. J Iron Steel Res Int. 16:17–21. doi: 10.1016/S1006-706X(09)60021-2
19.
XieXF, LiL, WangF, YuJQ, QiuSW, ZhangRJ.2015. Recovery of copper from chlorination dust of copper-containing slag by hydrometallurgical methods. Chin J Process Eng. 15:424–429. (in Chinese)
20.
ZhangLN, ZhangL, WangMY, SuiZT.2005. Oxidization mechanism in CaO-FeOX -SiO2 slag with high iron content. Trans Nonferrous Met Soc China. 15:938–943.
