Alkaline extraction characteristics of steelmaking slag batch in NH₄Cl solution under environmental pressure

Abstract

In order to obtain better carbonation effect, extraction behavior of slag batch is necessary to study. Relevant parameters like selective extraction yield were originally discussed. The relationship between selective extraction yield and conversion ratio was systemically focused on. The results show that alkaline earth metal conversion ratio is changed with leaching time and NH₄Cl concentration by first order exponential, and the maximum conversion for calcium keeps about 68% at 120 min in 0.4 mol/L NH₄Cl solution, while leaching temperature and particle size have a linear effect on conversion ratio. Selective extraction yield of calcium is more than 93%, and the value of Mg is less than 5%. Apparent layer bands of silicon and calcium appear in the surface area through morphology detection of slag after leaching, and the case for 38–75 μm slag batch is more obvious than 75–150 μm slag and slag with larger particle size when leaching in 0.4 mol /L NH₄Cl solution for 90 min at 60 °C.

Keywords

steel slag / alkaline leaching / NH₄Cl solution / selective extraction yield / conversion ratio

References

[1] HeH Y, NiH W, GanW G, LiuJ G, ChenJ. Resource utilization and evaluation of the steelmaking waste slag reuse in metallurgic flied [J]. J Wuhan Inst Tech, 2009, 31(1): 41-45

[2] LiuJ Q, ZhengY R, LiJ T, FengJ. Research about desulfurizing agent ingredients with EAF reduce slag base [J]. Energy for Metallurgical Industry, 2006, 25(3): 41-43

[3] GuoS X, DongY C, ChenE B, ZhangY P. Effect of converter steelmaking slag on desiliconization and dephosphorization of hot metal [J]. Journal of Iron And Steel Research, 2002, 14(6): 9-13

[4] ZhaoL H, CangD Q, LiuP, BaiH, TangQ. Preparation and microstructure analysis of CaO-MgO-SiO₂ steel-slag ceramics [J]. Journal of University of Science and Technology Beijing, 2011, 33(8): 995-1000

[5] YanG S B, LuoZ Z, WenY C, HeW, WangJ, ChenY. Vanadium recovery from BOF slag containing vanadium oxide [J]. Iron and Steel, 2005, 40(4): 72-75

[6] QianQ. Review of technology on extracting vanadium pentoxide from high calcium vanadium-bearing steel slag [J]. China Resources Comprehensive Utilization, 2009, 276: 15-17

[7] UibuM, KuusikR, AndreasL, KirsimäeK. The CO₂-binding by Ca-Mg-silicates in direct aqueous carbonation of oil shale ash and steel slag [J]. Energy Procedia, 2011, 4: 925-932

[8] ChenZ Y, O’ConnorW K, GerdemannS J. Chemistry of aqueous mineral carbonation for carbon sequestration and explanation of experimental results [J]. Environ Prog, 2006, 25(2): 160-166

[9] GerdemannS J, O’ConnorW K, DahlinD C, PennerL R, RushA. Ex situ aqueous mineral carbonation [J]. Environ Sci Technol, 2007, 41(7): 2587-2593

[10] WindtL D, ChaurandP, RoseJ. Kinetics of steel slag leaching: Batch tests and modeling [J]. Waste Manage, 2011, 31: 225-235

[11] ChangE E, PanS Y J J, ChenYH, ChuH S, WangC F, ChiangP C. CO₂ sequestration by carbonation of steelmaking slags in an autoclave reactor [J]. Hazard Mater, 2011, 195: 107-114

[12] HuijgenW J J, WitkampG J, ComansR N J. Mineral CO₂ sequestration by steel slag carbonation [J]. Environ Sci Technol, 2005, 39(24): 9676-9682

[13] KodamaS, NishimotoT, YamamotoN, YogoK, YamadaK. Development of a new pH-swing CO₂ mineralization process with a recyclable reaction solution [J]. Energy, 2008, 33: 776-784

[14] ZomerenA, VanderlaanS R, KobesenH B A, HuijgenW J J, ComansR N J. Changes in mineralogical and leaching properties of converter steel slag resulting from accelerated carbonation at low CO₂ pressure [J]. Waste Manage, 2011, 31: 2236-2244

[15] HuijgenW J J, WitkampG J, ComansR N J. Chem Mechanisms of aqueous wollastonite carbonation as a possible CO₂ sequestration process [J]. Eng Sci, 2006, 61: 4242-4251

[16] LekakhS N, RbertsonD G C, RawlinsC H, RichardsV L, PeasleeK D. Investigation of a two-stage aqueous reactor design for carbon dioxide sequestration using steelmaking slag [J]. Metall Mater Trans B, 2008, 39: 484-492

[17] TeirS, ElonevaS, FogelholmC J, ZevenhovenR. Dissolution of steelmaking slags in acetic acid for precipitated calcium carbonate production [J]. Energy, 2007, 32: 528-539

[18] SunY, YaoM S, ZhangJ P, YangG. Indirect CO₂ mineral sequestration by steelmaking slag with NH₄Cl as leaching solution [J]. Chem Eng J, 2011, 173: 437-445

[19] PtášekP, NoskováM, BrandštetrJ, ŠoukalF, OpravilT. Dissolving behavior and calcium release from fibrous wollastonite in acetic acid solution [J]. Thermochim Acta, 2010, 498: 54-60

[20] WorrellE, PriceL, MartinN. Energy efficiency and carbon dioxide emissions reduction opportunities in the US iron and steel sector [J]. Energy, 2001, 26(5): 513-536

[21] HuijgenW J J, WitkampG J, ComansR N J. Cost evaluation of CO₂ sequestration by aqueous mineral carbonation [J]. Energy Convers Manage, 2007, 48: 1923-1935

[22] HuijgenW J J, WitkampG J, ComansR N J. Energy consumption and net CO₂ sequestration of aqueous mineral carbonation [J]. Ind Eng Chem Res, 2006, 45(26): 9184-9194