SciELO - Scientific Electronic Library Online

vol.109 issue1Furnace energy efficiency at Polokwane SmelterDevelopment of roasting parameters for the ConRoast process with low-sulphur feedstock author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Journal of the Southern African Institute of Mining and Metallurgy

On-line version ISSN 2411-9717
Print version ISSN 0038-223X

J. S. Afr. Inst. Min. Metall. vol.109 n.1 Johannesburg Jan. 2009




Towards electrode immersion control on Lonmin's no. 1 circular furnace



G.A. GeorgalliI; J.J. EksteenII; R. BezuidenhoutII; B. van BeekII; T. GoffII

IUniversity of Stellenbosch, South Africa
IILonmin, South Africa




A control philosophy to be applied by Lonmin to maintain constant electrode immersion in their no. 1 circular smelting furnace is put forward. This control philosophy is facilitated though a combination of thermodynamic models used to predict the slag composition and empirical correlations to estimate the furnace eometric factor as well as the slag conductivity. The model can determine the operating resistance setpoint required in order to maintain a desired electrode immersion as a function of the feeds to the furnace, slag level and temperature. If modifying the resistance setpoint cannot maintain the desired immersion without moving out of the furnace P-V-I operating envelope, the model can be used to determine the amount of slag modifiers (silica or lime) required to shift the slag chemistry back into a region where the immersion can be controlled though resistance setpoint manipulation.



“Full text available only in PDF format”




1. HUNDERMARK, R. The electrical conductivity of melter type slags. Master's thesis, University of Cape Town, 2003.         [ Links ]

2. GEORGALLI, G.A., EKSTEEN, J.J. and REUTER, M.A. An integrated thermochemical-systems approach to the prediction of matte composition dynamics in an Ausmelt® nickel-copper matte converter. Minerals Engineering, vol. 15, 2002. pp. 909-917.         [ Links ]

3. EKSTEEN, J.J., GEORGALLI, G.A. and REUTER, M.A. Online prediction of the actual melt chemistry in an Ausmelt converter using a thermodynamic - system identification hybrid modelling technique. Proceedings of the Third International Sulphide Smelting Symposium, Seattle, February 2002. TMS. pp. 457-468.         [ Links ]

4. LONMIN PLC. Mineralogical and chemical analyses of the smelter primary and secondary concentrate streams and recycle streams. Personal communication.         [ Links ]

5. LONMIN PLC. Lonmin dry concentrate delivery plan. Personal communication, 2008.         [ Links ]

6. JIAO, Q. and THEMELIS, N.J. Correlation of geometric factor for slag resistance furnaces. Metallurgical and Materials Trasactions B, vol. 22B 1991. pp. 182-192.         [ Links ]

7. SHENG, Y.Y., IRONS, G.A. and TISDALE, D.G. Transport phenomena in electric smelting of nickel matte: Part I. Electric potential distribution. Metallurgical and Materials Transactions B, vol. 29B 1998. pp. 77-83.         [ Links ]

8. UTIGARD, T.A. and WARCZOK, A. Density and viscosity of copper/nickel sulphide smelting and converting slags. Proceedings of COPPER 95 - COBRE 95 International Conference, vol. IV - Pyrometallurgy of Copper, 1995. pp. 423-437.         [ Links ]

9. ZHANG, L., JAHANSHAHI, S., SUN, S., LIM, M., BOURKE, B., WRIGHT, S. and SOMERVILLE, M. Development and applications of models for pyrometallurgical processes. Materials Forum, vol. 25, 2001. pp. 136-153.         [ Links ]

10. DE NEVERS, N. Fluid mechanics for chemical engineers. McGraw-Hill, 2nd edition, 1991.         [ Links ]

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License