Journal of Thermal Analysis and Calorimetry

, Volume 134, Issue 3, pp 2171–2181 | Cite as

Thermodynamic analysis on molten slag waste heat cascade recovery method (MS-WHCR)

  • Zongliang Zuo
  • Qingbo Yu
  • Huaqing Xie
  • Sihong Liu
  • Junxiang Liu
  • Fan Yang
  • Qin Qin


Thermal energy recovery of pyrometallurgy slags is a worldwide problem that is widely concerned for decades. As chemical recovery method, molten slag cascade recovery method (MS-WHCR) is proposed in this work. As typical endothermic chemical reactions, pyrolysis, gasification, calcination and reforming reactions are applied in this method. Gasification–pyrolysis system, calcination–pyrolysis system, enhanced pyrolysis system (R-SEP) and fixed carbon gasification and sorption-enhanced pyrolysis system (CG–SEP) systems of MS-WHCR method are designed. Based on the first law of thermodynamics and second law of thermodynamics, enthalpy–exergy compass analysis method is applied to analyze the exergy efficiency, consumption of reactants and products of designed MS-WHCR method, compared with traditional water quenched (WQ) method and gravity bed waste heat recovery (GWHR) method. As calculation example, 1000kg copper slag is used in this paper. The results showed that the exergy efficiency and exergy loss of WQ method are 20.7% and −947 MJ respectively. By WQ method, energy quality of molten copper slag is discounted. Copper slag particles should be fast cooled during granulation process. Thus, lots of air is blown in to make enough heat transfer with copper slag particles, which generate some exergy loss. And exergy efficiency of GWHR method is 76.9%. Using chemical endothermic reactions, MS-WHCR method improves the exergy efficiency of molten slag waste heat recovery. There is a slight fluctuation of exergy efficiency by MS-WHCR method for four kinds of systems from 66.6 to 70.1%. Fixed carbon and combustible syngas are acquired by MS-WHCR. And enhanced pyrolysis process in proposed R-SEP and CG–SEP systems improves hydrogen contents in syngas.


Thermodynamic analysis Thermodynamic compass Molten slag Waste heat recovery 



The authors would like to acknowledge the support from The Major State Research Development Program of China (2017YFB0603603).


  1. 1.
    Wang H, Wu J, Zhu X, Liao Q, Zhao L. Energy–environment–economy evaluations of commercial scale systems for blast furnace slag treatment: dry slag granulation vs. water quenching. Appl Energy. 2016;171:314–24.CrossRefGoogle Scholar
  2. 2.
    Gorai B, Jana RK. Characteristics and utilisation of copper slag—a review. Resour Conserv Recycl. 2003;39(4):299–313.CrossRefGoogle Scholar
  3. 3.
    Liu J, Yu Q, Zuo Z, Duan W, Han Z, Qin Q, Yang F. Experimental investigation on molten slag granulation for waste heat recovery from various metallurgical slags. Appl Therm Eng. 2016;103:1112–8.CrossRefGoogle Scholar
  4. 4.
    Zhang H, Wang H, Zhu X, Qiu Y, Li K, Chen R, Liao Q. A review of waste heat recovery technologies towards molten slag in steel industry. Appl Energy. 2013;112:956–66.CrossRefGoogle Scholar
  5. 5.
    Li P. Thermodynamic analysis of waste heat recovery of molten blast furnace slag. Int J Hydrog Energy. 2017;42(15):9688–95.CrossRefGoogle Scholar
  6. 6.
    Liu J, Yu Q, Peng J, Hu X, Duan W. Thermal energy recovery from high-temperature blast furnace slag particles. Int Commun Heat Mass Transf. 2015;69:23–8.CrossRefGoogle Scholar
  7. 7.
    Kashiwaya Y, Akiyama T, Yutaro IN. Latent heat of amorphous slags and their utilization as a high temperature PCM. ISIJ Int. 2010;50(9):1259–64.CrossRefGoogle Scholar
  8. 8.
    Kashiwaya Y, Yutaro IN, Akiyama T. Development of a rotary cylinder atomizing method of slag for the production of amorphous slag particles. ISIJ Int. 2010;50(9):1245–51.CrossRefGoogle Scholar
  9. 9.
    Kashiwaya Y, Yutaro IN, Akiyama T. Mechanism of the formation of slag particles by the rotary cylinder atomization. ISIJ Int. 2010;50(9):1252–8.CrossRefGoogle Scholar
  10. 10.
    Nomura ONT, Akiyama T. Technology of latent heat storage for high temperature application: a review. ISIJ Int. 2010;50(9):1229–39.CrossRefGoogle Scholar
  11. 11.
    Li P, Yu Q, Xie H, Qin Q, Wang K. CO2 gasification rate analysis of datong coal using slag granules as heat carrier for heat recovery from blast furnace slag by using a chemical reaction. Energy Fuels. 2013;27(8):4810–7.CrossRefGoogle Scholar
  12. 12.
    Luo S, Fu J, Zhou Y, Yi C. The production of hydrogen-rich gas by catalytic pyrolysis of biomass using waste heat from blast-furnace slag. Renew Energy. 2017;101:1030–6.CrossRefGoogle Scholar
  13. 13.
    Shimada T, Kochura V, Akiyama T, Kasai E, Jun-Ichiro Y. Effects of slag compositions on the rate of methane-steam reaction. Trans Iron Steel Inst Jpn. 2001;41(2):111–5.CrossRefGoogle Scholar
  14. 14.
    Maruoka N, Mizuochi T, Purwanto H, Akiyama T. Feasibility study for recovering waste heat in the steelmaking industry using a chemical recuperator. ISIJ Int. 2007;44(2):257–62.CrossRefGoogle Scholar
  15. 15.
    Akiyama T, Oikawa K, Shimada T, Kasai E, Jun-Ichiro Y. Thermodynamic analysis of thermochemical recovery of high temperature wastes. Trans Iron Steel Inst Jpn. 2000;40(3):286–91.CrossRefGoogle Scholar
  16. 16.
    Kasai E, Kitajima T, Akiyama T, Yagi J, Saito F. Rate of methane-steam reforming reaction on the surface of molten bf slag-for heat racovery from molten slag by using a chemical reaction. ISIJ Int. 2007;37(10):1031–6.CrossRefGoogle Scholar
  17. 17.
    Purwanto H, Akiyama T. Hydrogen production from biogas using hot slag. Int J Hydrog Energy. 2006;31(4):491–5.CrossRefGoogle Scholar
  18. 18.
    Li P, Qin Q, Yu Q, Du W. Feasibility study for the system of coal gasification by molten blast furnace slag. Adv Mater Res. 2010;97–101:2347–51.CrossRefGoogle Scholar
  19. 19.
    Li P, Yu Q, Qin Q, Liu J. Adaptability of coal gasification in molten blast furnace slag on coal samples and granularities. Energy Fuels. 2011;25(12):5678–82.CrossRefGoogle Scholar
  20. 20.
    Akiyama T, Mizuochi T, Yagi JI, Nogami H. Feasibility study of hydrogen generator with molten slag granulation. Steel Res Int. 2004;75(2):122–7.CrossRefGoogle Scholar
  21. 21.
    Duan W, Yu Q, Wang K, Qin Q, Hou L, Yao X, Wu T. ASPEN plus simulation of coal integrated gasification combined blast furnace slag waste heat recovery system. Energy Convers Manag. 2015;100:30–6.CrossRefGoogle Scholar
  22. 22.
    Mohan D, Pittman CU, Steele PH. Pyrolysis of wood/biomass for bio-oil: a critical review. Energy Fuels. 2006;20(3):848–89.CrossRefGoogle Scholar
  23. 23.
    Richardson Y, Blin J, Julbe A. A short overview on purification and conditioning of syngas produced by biomass gasification: catalytic strategies, process intensification and new concepts. Prog Energy Combust Sci. 2012;38(6):765–81.CrossRefGoogle Scholar
  24. 24.
    Bridgwater AV. Review of fast pyrolysis of biomass and product upgrading. Biomass Bioenerg. 2012;38:68–94.CrossRefGoogle Scholar
  25. 25.
    Rozhan AN, Cahyono RB, Yasuda N, Nomura T, Hosokai S, Akiyama T. Carbon deposition of biotar from pine sawdust by chemical vapor infiltration on steelmaking slag as a supplementary fuel in steelworks. Energy Fuels. 2012;26(6):3196–200.CrossRefGoogle Scholar
  26. 26.
    Luo S, Zhou Y, Yi C. Hydrogen-rich gas production from biomass catalytic gasification using hot blast furnace slag as heat carrier and catalyst in moving-bed reactor. Int J Hydrog Energy. 2012;37(20):15081–5.CrossRefGoogle Scholar
  27. 27.
    Xie H, Zhang J, Yu Q, Zuo Z, Liu J, Qin Q. Study on steam reforming of tar in hot coke oven gas for hydrogen production. Energy Fuels. 2016;30(3):2336–44.CrossRefGoogle Scholar
  28. 28.
    Zuo Z, Yu Q, Xie H, Duan W, Liu S, Qin Q. Thermogravimetric analysis of the biomass pyrolysis with copper slag as heat carrier. J Therm Anal Calorim. 2017;129(2):1233–41.CrossRefGoogle Scholar
  29. 29.
    Tomishige K, Kimura T, Nishikawa J, Miyazawa T, Kummori K. Promoting effect of the interaction between Ni and CeO2 on steam gasification of biomass. Catal Commun. 2007;8(7):1074–9.CrossRefGoogle Scholar
  30. 30.
    Cao Y, Wang Y, Riley JT, Pan W. A novel biomass air gasification process for producing tar-free higher heating value fuel gas. Fuel Process Technol. 2006;87(4):343–53.CrossRefGoogle Scholar
  31. 31.
    Henriksen U, Ahrenfeldt J, Jensen TK, Gøbel B, Bentzen JD, Hindsgaul C. The design, construction and operation of a 75 kw two-stage gasifier. Energy. 2006;31(10–11):1542–53.CrossRefGoogle Scholar
  32. 32.
    Heo JH, Kim BS, Park JH. Effect of CaO addition on iron recovery from copper smelting slags by solid carbon. Metall Mater Trans B. 2013;44(6):1352–63.CrossRefGoogle Scholar
  33. 33.
    Zuo Z, Yu Q, Liu J, Qin Q, Xie H, Yang F. Effects of CaO on reduction of copper slag by biomass based on ion and molecule coexistence theory and thermogravimetric experiments. ISIJ Int. 2017;57(2):220–7.CrossRefGoogle Scholar
  34. 34.
    Li L, Wang H. Response characteristics of iron smelting reduction of copper slags. Mater Res Innov. 2015;19(sup5):S5-469.CrossRefGoogle Scholar
  35. 35.
    Zuo Z, Yu Q, Wei M, Xie H, Duan W, Wang K, Qin Q. Thermogravimetric study of the reduction of copper slag by biomass. J Therm Anal Calorim. 2016;126(2):481–91.CrossRefGoogle Scholar
  36. 36.
    Zhang H, Shi X, Zhang B, Hong X. Reduction of molten copper slags with mixed CO–CH4–Ar gas. Metall Mater Trans B. 2013;45(2):582–9.Google Scholar
  37. 37.
    Zhang L, Zhang L, Wang M. Oxidization mechanism in CaO–FeOx–SiO2 slag with high iron content. Nonferr Metal Soc. 2006;20(1):79–82.Google Scholar
  38. 38.
    Bruckard WJ, Somerville M, Hao F. The recovery of copper, by flotation, from calcium-ferrite-based slags made in continuous pilot plant smelting trials. Miner Eng. 2004;17(4):495–504.CrossRefGoogle Scholar
  39. 39.
    Warczok A, Riveros G. Slag cleaning in crossed electric and magnetic fields. Miner Eng. 2007;20(1):34–43.CrossRefGoogle Scholar
  40. 40.
    Jin L, Wang H, Liu H, Hu J. Mechanism research of calcined copper slag catalytic steam reforming jatropha oil. J Renew Sustain Energy. 2016;8(6):10–5.CrossRefGoogle Scholar
  41. 41.
    Zhang F, Hu J, Yang B, Yu Y. Syngas production from biomass gasification using copper slag catalysts. Adv Mater Res. 2013;724–725:313–8.Google Scholar
  42. 42.
    Deng S, Hu J, Wang H, Li J, Hu W. An experimental study of steam gasification of biomass over precalcined copper slag catalysts. Adv Mater Res. 2013;634–638(1):479–89.CrossRefGoogle Scholar
  43. 43.
    Ishida M. Thermodynamics-its perfect comprehension and applications. Tokyo p: Baifukan; 1995. p. 93 (in Japanese).Google Scholar
  44. 44.
    Akiyama T, Oikawa K, Shimada T, Kasai E, Yagi J. Thermodynamic analysis of thermochemical recovery of high temperature wastes. ISIJ Int. 2000;40(3):286–91.CrossRefGoogle Scholar
  45. 45.
    Duan W, Yu Q, Qin Q, Hou L. Thermodynamic analysis of bf slag waste heat recovery system using enthalpy-exergy diagram. J Northeast Univ Nat Sci. 2014;35(11):1566–70.Google Scholar
  46. 46.
    Akiyama T, Yag J. Methodology to evaluate reduction limit of carbon dioxide emission and minimum exergy consumption for ironmaking. ISIJ Int. 1998;38(8):896–903.CrossRefGoogle Scholar
  47. 47.
    Fan LC, Akshat T. Review of recent developments in Ni-based catalysts for biomass gasification. J Renew Sustain Energy. 2014;38(5):428–38.Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2018

Authors and Affiliations

  • Zongliang Zuo
    • 1
  • Qingbo Yu
    • 1
  • Huaqing Xie
    • 1
  • Sihong Liu
    • 1
  • Junxiang Liu
    • 1
  • Fan Yang
    • 1
  • Qin Qin
    • 1
  1. 1.School of MetallurgyNortheastern UniversityShenyangPeople’s Republic of China

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