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Characterization of Ajebo Kaolinite Clay for Production of Natural Pozzolan

Authors: Gbenga M. Ayininuola, Olasunkanmi A. Adekitan


Calcined kaolinite clay (CKC) is a pozzolanic material that is current drawing research attention. This work investigates the conditions for the best performance of a CKC from a kaolinite clay source in Ajebo, Abeokuta (southwest Nigeria) known for its commercial availability. Samples from this source were subjected to X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). XRD shows that kaolinite is the main mineral in the clay source. This mineral is responsible for the pozzolanic behavior of CKC. DSC indicates that the transformation from the clay to CKC occurred between 550 and 750 oC. Using this temperature range, clay samples were milled and different CKC samples were produced in an electric muffle furnace using temperatures of 550, 600, 650, 700, 750 and 800 oC respectively for 1 hour each. This was also repeated for 2 hours. The degree of de-hydroxylation (dtg) and strength activity index (SAI) were also determined for each of the CKC samples. The dtg and SAI tests were repeated two more times for each sample and averages were taken. Results showed that peak dtg occurred at 750 oC for 1 hour calcining combination (94.27%) whereas marginal differences were recorded at some lower temperatures (90.97% for 650 oC for 2 hours; 91.05% for 700 oC for 1 hour and 92.77% for 700 oC for 2 hours). Optimum SAI was reported at 700 oC for 1 hour (99.05%). Rating SAI as a better parameter than dtg, 700 oC for 1 hour combination was adopted as the best calcining condition. The paper recommends the adoption of this clay source for pozzolan production by adopting the calcining conditions established in this work.

Keywords: Calcined kaolinite clay, calcination, optimum-calcining conditions, pozzolanity.

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[1] L. Adeloye, “Cement: New investment yield 8.5million metric tones”, Punch Newspapers feature article. Lagos Nigeria: Punch Newspapers, pp26, June 10, 2011.
[2] J. Davidovits, “Geopolymer cement – a review”. Saint-Quentin, France: Institut Géopolymère, 2008.
[3] United States Department of Energy, USDoE, “Energy and Emission Reduction Opportunities for the Cement Industry”, Technical Paper for Industrial Technologies Program. December 2003. Retrieved January 30th, 2013 from
[4] O. O. Amu, S. A. Ogunniyi, and, O. O. Oladeji.“Geotechnical properties of lateritic soil stabilised with sugarcane straw ash”, American Journal of Scientific and Industrial Research, vol.2, no. 2, 2011, pp.323-331.
[5] J. M. Justice, “Evaluation of metakaolins for use as supplementary cementitious materials”, Unpublisshed M. Sc thesis, School of Material Science and Engineering, Georgia Institute of Technology, 2005.
[6] K. G. Kolovos, P. G. Asteris, D.M. Cotsovos, E. Badogiannis and, S. Tsivilis, “Mechanical properties of soilcrete mixtures modified with metakaolin”, Construction and Building Materials, vol. 47, 2013, pp. 1026–1036.
[7] M. A. Aboubakar, E. Ganjian, H. Pouya, and, A. Akashi, “A study on the effect the addition of thermally treated Libyan natural pozzolan has on the mechanical properties of ordinary Portland cement mortar”,
[8] International Journal of Science and Technology, vol. 3, no. 1, 2013, pp. 79-84.
[9] O. Adekitan, A. O. Oyerinde and, M. B. Jaji, “Comparative compressive strength assessment of cement concretes blended with two locally produced natural pozzolans”, Proceedings of 7th Applied Research Conference in Africa, Ibadan, Nigeria, August, 2015.
[10] J. M.Justice, et al.,“Comparison of two metakaolins and silica fume used as supplementary cementitious material”Proceeding of the Seventh International Symposium on Utilization of High-Strength/High Performance Concrete, Washington DC, June 20-24, 2005.
[11] J. M.Justice, andK. E.Kurtis, “Influence of metakaolin surface area on properties of cement-based materials”, ASCE Journal of Materials in Civil Engineering, vol. 19, no. 9, 2007, pp. 762 – 771.
[12] R. Fernandez, F. Martirena and, K. L. Scrivener, “The origin of the pozzolanic activity of clay minerals: A comparison between kaolinite, illite and montmorillonite”, Cement and Concrete Research, vol. 41, 2011, pp. 113-122.
[13] T. Phung-Thi, “Metakaolin as an additive in composite cement”,A PhD Thesis submitted to the Faculty of Civil Engineering, Weimar Bauhaus University, 2013.
[14] B. B. K. Diffo, A. Elimbi, M. Cyrb,J. D. Mangac and, H. T. Kouamoa,”Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers”, Journal of Asian Ceramic Societies vol. 3, 2015, pp. 130–138. .12.003
[15] B. R. Ilić, A. A. Mitrović and, L. R. Miličić, “Thermal treatment of kaolin clay to obtain metakaolin”, Hem. Ind.,vol.64, no. 4, 2010, pp. 351–356. doi: 10.2298/HEMIND100322014I
[16] F. Moodi, A. A. Ramezanianpour and, A. S. Safavizadeh, “Evaluation of the optimal process of thermal activation of kaolins”, Scientia Iranicavol. 18, no. 4, 2011, pp. 906–912. doi:10.1016/j.scient.2011.07.011
[17] M. A. Soleimani, R. Naghizadeh,A. R. Mirhabibi and, F. Golestanifard, “Effect of calcination temperature of the kaolin and molar Na2O/SiO2 activator ratio on physical and microstructural properties of metakaolin based geopolymers”, Iranian Journal of Materials Science & Engineering, vol. 9, no. 4,2012, pp. 43-51
[18] G. Kakali, T. Perraki, S. TsivillisandE. Badogiannis, “Thermal treatment of kaolin: the effect of mineralogy on the pozzolanic activity”, Applied Clay Science,vol.20, 2001, pp. 73-80.
[19] O. E. Akhirevbulu,C. V. O. Amadasun,M. I. Ogunbajoand,O. Ujuanbi,“The geology and mineralogy of clay occurrences around Kutigi Central, Bida Basin, Nigeria”, Ethiopian Journal of Environmental Studies and Management,vol. 3, no. 3, 2010, 49-56.
[20] T. U. S. Onyeobi, E. G. Imeokparia, O. A. Ilegieuno and, I. G. Egbuniwe, “Compositional, geotechnical and industrial characteristics of some clay bodies in Southern Nigeria”, Journal of Geography and Geology, vol. 5, no. 2, 2013, 73-84.
[21] B. S.Badmus, O. T. Olurin, S. A. Ganiyu and, O. T.Oduleye, “Evaluation of physical parameters of various solid minerals within southwestern Nigeria using direct experimental laboratory methods”,American International Journal of Contemporary Research vol. 3, no. 3,2013, pp. 152-161.
[22] A. Tironi, M. A, Trezza, A. N.Scian and, E. F. Irassar, “Kaolinitic calcined clays: Factors affecting its performance as pozzolans”,Construction and Building Materials, vol. 28, 2012, pp. 276–281
[23] B. S. Badmus and, O. B. Olatinsu, “Geophysical evaluation and chemical analysis of kaolinite rocks/clay rocks/clays deposit of Lakiri village, southwestern Nigeria, International Journal of Physical Sciences, vol. 4, no. 10,2009, pp. 592-606.
[24] Raw Materials Reasearch and Development Council (RMRDC), Non-Metallic Mineral Endowmwnts in Nigeria. Abuja, Nigeria: Raw Materials Reasearch and Development Council (RMRDC), 2010.
[25] O. S. Olokode and, P. O. Aiyedun, “Mineralogical characteristics of natural kaolins from Abeokuta, South-West Nigeria”,The Pacific Journal of Science and Technology,vol. 12, no. 2, 2011, pp. 558-565.
[26] ASTM C618-12,Standard specification for coal fly ash and raw or calcined natural pozzolan for use in concrete. US: ASTM International, 1994.
[27] ASTM D7348-13,Standard test method for loss on ignition (LOI) of solid combustion residues. US: ASTM International, 2013.
[28] ASTM C311/C311M-13,Standard test methods for sampling and testing fly ash or natural pozzolan for use in Portland-cement concrete. US: ASTM International, 2013.
[29] ASTM C109/C109M-13e1, Standard test methods for compressive strength of hydraulic cement mortars (using 2-in. or
[50-mm] cube specimens). US: ASTM International. 2013.
[30] D. P.Bentz, E. J.Garboczi, C. J.Haecker and, O. M. Jensen, “Effects of cement particle size distribution on performance properties of Portland cement-based materials”, Cement and Concrete Research, vol. 29, no.10, 1999, pp. 1663-1671
[31] O. S.Olokode, P. O. Aiyedun, S. I. Kuye, N. O. Adekunle and, W. E. Lee, “Evaluation of a clay mineral deposit in Abeokuta, South-west Nigeria”,Journal of Natural Sciences Engineering and Technology,vol. 9, no.1, 2010, pp. 132-136.
[32] G. P.Souza, S. J.Sousa, L. A.Terrones and, J. N. Holanda, “Mineralogical analysis of Brazilian ceramic sedimentary clays used in red ceramic”,Cerâmica, vol. 51,no. 320, 2005.
[33] E. Tiffo, A. Elimbi, J. D. Manga and, A. B. Tchamba, “Red ceramics produced from mixtures of kaolinite clay and waste glass”,Brazilian Journal of Science and Technology, vol. 2, no. 4, 2015, pp. 1-13. DOI 10.1186/s40552-015-0009-9