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Nicola Wagner

Name: Nikki Wagner
Location: C1 Lab 306 Auckland Park Kingsway Campus
Department of Geology Staff  Staff Members

Contact Details:
Tel: +27 (0)11 559 4719


About Prof Nikki Wagner

Prof Nikki (Nicola) Wagner is the Director of the DSI-NRF Centre of Excellence in Integrated Mineral and Energy Resource Analysis (CIMERA), and Professor in the Geology Department at the University of Johannesburg, Johannesburg, South Africa. Her research areas include organic petrology, coal petrography, trace elements and critical raw materials in coal and associated products, coal geology, carbon dioxide capture and storage, coal oxidation, underground coal gasification, coal conversion, ash utilisation, and so on. She graduated from RHBNC, London, with a geology-zoology Honours degree, and completed her PhD in 1998 (Wits). Shortly thereafter, Dr Wagner worked for Sasol in their Coal to Syngas Research Group, as the inhouse coal petrographer. Prof Wagner joined the School of Chemical and Metallurgical Engineering at the University of the Witwatersrand, Johannesburg, in 2006, where she ran the Coal Research group for 8 years before moving back into geology at the University of Johannesburg in 2014. Prof Wagner has over 70 peer reviewed publications and produced a book on coal petrology. She has graduated over 45 postgraduate students, and is an active peer reviewer for over 10 research journals, is accredited by the International Committee for Organic Petrology (ICCP), and is the elected editor of the ICCP News, where she also serves on the Council. Prof Wagner is a Fellow of the Geological Society of South Africa (GSSA), and member of the FFF-C, SEG, and SACNASP, and has a B NRF rating. Prof Wagner has three children.

Research interests

Organic petrology, coal petrography, trace elements and critical raw materials in coal and associated products, coal geology, carbon dioxide capture and storage, coal oxidation, underground coal gasification, coal conversion, ash utilisation, and so on.


Coal lectures in Economic Geology Honours module; writing skills; training on organic petrology / coal petrography.

Recent publications

  • Rerani, V.P., Mabowa, H.M., Wagner, N.J. 2024. Characterisation of rare earth element-bearing mineral phases present in South African coal ash using Mineral Liberation Analysis. Fuel. (accepted)
  • Santos, A.C., Badenhorst, C., Białecka, B., Cameán, I., Guedes, A., Moreira, K., Predeanu, G., Suárez‐Ruíz, I., Wagner, M., Valentim, B. 2024. Graphitization of coal char: microstructural and microtextural transformations. International Journal of Coal Geology 285, 104470
  • Langa, W.M., Ndou, C., Zieger, L., Harris, P., Wagner, N. 2024. Hyperspectral imaging of coal core: a focus on the visible-near-shortwave infrared (VN-SWIR) region. International Journal of Coal Geology (accepted Feb 2024).
  • Moroeng, O., Murathi, B., Wagner, N.J. 2024. Enrichment of rare earth elements in epigenetic dolomite occurring in contact metamorphosed Witbank coals (South Africa). International Journal of Coal Geology 282 104405.
  • Chabalala, V., Wagner, N., Malumbazo, N. 2023. Application of Organic Petrology and Raman Spectroscopy in Thermal Maturity Determination of the Karoo Basin (RSA) Shale Samples. Minerals 13, 1199;
  • Chitlango, F.Z., Wagner, N.J., Moroeng, O.M. 2023. Characterization and pre-concentration of rare earth elements in density fractionated samples from the Waterberg Coalfield, South Africa. International Journal of Coal Geology 275, 104299.
  • Soqinase, S., Steenkamp, J.D., den Hoed, P., Wagner, N. 2023. The effect of petrographically determined parameters on reductant reactivity in the production of high-carbon ferromanganese. Journal of the Southern African Institute of Mining and Metallurgy, vol. 123, no. 2, pp. 71–80.
  • Sebola, M.J.T., Drennan, G.R., Wagner, N.J. 2022. Petrographic and geochemical characteristics of beneficiated metallurgical coal from the No. 6 Seam, Tshipise sub-basin, Soutpansberg coalfield, South Africa. Journal of the South African Institute of Mining and Metallurgy, vol 122: 8, 461-472.
  • Mahooana, P., Moroeng, O.M., Wagner, N.J. 2022. Petrology of the A and B Seams, Ermelo Coalfield (South Africa): Indications for changing paleoenvironmental and sedimentary conditions. International Journal of Coal Geology. 263, 104135.
  • Dai, S., Arbuzov, S.I., Chekryzhov, I.Y., French, D., Feole, I., Folkedahl, B.C., Graham, I.T., Hower, J.C., Nechaev, V.P., Wagner, N.J., et al. 2022. Metalliferous Coals of Cretaceous Age: A Review. Minerals 12, 1154.
  • Chukwuma, K., Tsikos, H., Wagner, N., Frazenburg, M. 2022. Dual Sea-Level-Climatic Controls on the Stratigraphic Distribution of Total Organic Carbon Content and Macerals in the Permian Black Shales of Southwest Gondwana. J. of African Earth Sciences 188, 104495.
  • Mavhengere, P., Wagner, N., Bada S., Malumbazo, N. 2022. Physical and structural changes in the Zululand Basin (South Africa) Cenomanian Sandstone Core sample associated with long term supercritical CO2 and SO2 exposure. Journal of Petroleum Science and Engineering 215, 110554.
  • Mangs, A. D., Wagner, N.J., Moroeng, O.M., Lar, U.A. 2022. Petrographic composition of coal within the Benue Trough, Nigeria and a consideration of the paleodepositional setting. International Journal of Coal Science and Technology. 9:35.
  • Mokhahlane, L.S., Wagner, N.J., Vermeulen, D. 2022. Evidence of coal conversion in the Majuba underground coal gasification pilot plant, South Africa. Coal Combustion and Gasification Journal. March; 33964.