This study deals with two clays referenced K1 and K2, used in the local and traditional manufacture of pottery ware at Katiola. Those samples were analysed by X-rays diffraction, infrared spectroscopy and thermal differential and chemical techniques. The results show that the samples (K1 and K2) are mainly composed of montmorillonite, kaolinite and illite. Only K1 is inter-stratified. The mineralogical balance achieved from the reflection (001) of the oriented film, indicate for K1: 74.5% of montmorillonite; 13.5% of inter-stratified clay; 7% of kaolinite and 5.4% of illite and for K2: 73.4% of montmorillonite; 23.5% of kaolinite and 3.1% of illite. The results also indicate that the raw material may not be use only for pottery. It can be consider in the protection of the environment, cosmetic industry, vegetable oil treatment, medicine etc.
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Clay has always played a major role in human life since it has a wide range of applications. The technological properties of clay raw materials depend on it mineralogical composition (Konta, 1995; Montes et al., 2003). Several studies have demonstrated the relationship between crystal structure or crystal chemistry of the dominant phyllosilicate and the technological properties of clay: in the production of foods, beverage, paper, rubber, plastics, artificial leather, protective coatings for interior or exterior use, pharmaceutics, cosmetics, paints, porcelain, fine ceramics, coarse ceramics and various branches of the chemical, petroleum and cement industries, agricultural, health, water treatment, civil engineering and environment (Ferrandon et al., 1998; Elkebrokk and Saltnes, 2001; Cases, 2002; Hizal and Apak, 2006; Liang-Guo et al., 2007; Assaad et al., 2007).
The Bentonite was proposed as a barrier to protect against nuclear waste storage at its very high swelling-shrinkage and water adsorption potentiality (Pusch, 1992; Kacha et al., 1997; Al-Tabbaa and Aravinthan, 1998). The experimental absorption reveals that clay may be quite effective in removing basic dyes like methylene blue and Congo red (Dipa et al., 2002; Mumin et al., 2007).
More knowledge about clay raw materials is need to sustain the application suitable domains in Cĉte dIvoire, it is necessary to gather as much as possible all the information on the raw materials.
The clayey deposits from Cĉte dIvoire have been studied in detailed, except that of the city of Katiola (Andji et al., 2001; Andji, 2006; Konan, 2006). However clay raw materials of Katiola (in center of Cĉte dIvoire) are abundantly being used in pottery by the women (called Mangoros) organized in cooperative for several decades. The characteristics of these raw materials are completely unknown by the Mangoros who still use traditional techniques to produce the wares of pottery with a high rate of loss due to the drying technique they applied. This loss implies a drastic reduction in their income.
The present study investigates with different techniques the physicochemical and mineralogical characteristics of the raw materials of Katiola.
MATERIALS AND METHODS
Two samples of clays (K1 and K2) used in this study are from the deposit of Katiola, a city located in the centre of Cĉte dIvoire. The accurate geographic coordinates of the samples K1 and K2 obtained from a Global Positioning System are, respectively K1(N: 08° 14.709; W: 005°06.505) and K2 (N: 08°08.945; W: 005°05.959 ).
A quantometer Jobin-Yvon 70-P equipped with ICP (Inductively Coupled Plasma) plasma was used to make the chemical analysis in total rock.
The x-rays diffraction was done with a Bruckers D8 diffractometer that use Co-Kα monochromatic radiation (λ = 1.7889 Å) at ambient temperature over the domain 3≤θ≤35.
The absorption spectra are carried out in the field of the mean infrared, that is to say for numbers of wave (v = 1/λ) ranging between 400 and 4000 cm-1. Measurements were taken in diffuse reflection). In order to minimize the loss of energy, the samples are diluted in a KBr (70 mg of sample for 370 mg of KBr). The device used is a Fourier transform infrared spectrometer (Brucker YEWS 55). This device has a laser He-Ne and a high sensitive large bandwidth of wavelength (6000-600 cm-1) detector of type MCT (Cadmium and Mercury Telluride).
The DTA-TGA was carried out with a device ATD Linseis, an entirely automated differential thermal analyser. The samples have been ground to a granulometry lower to 100 μm. The reference is a charred alumina and the trial mass is 70 mg for the sample and the reference. The powders are packed slightly and the measures were carried out in identical platinum crucibles according to a programme for heating, run at 10°C min-1 under an air atmosphere.
RESULTS AND DISCUSSION
Chemical analysis: The chemical analysis results are presented in Table 1. From the analysis, one can see that the samples (K1 and K2) have similar composition. Silica, alumina and iron are the main constituents of those samples. However, the percentage of alumina and iron is higher in K2 than in K1. The results also reveal the presence of a relatively important amount of Mg in the samples. Nevertheless, the percentage of Mg is higher in K1 than in K2. For what concern the chemical elements Ca, Na and K, the percentage is not negligible for K1 but quasi inexistent for K2.
X-rays diffraction: Figure 1 shows the results of the analysis made with the X-rays diffraction. The diagrams were obtained from normal films and Ethylene Glycol (EG) saturated films. The patterns exhibit predominantly the presence of inflating minerals in K1 and K2 (Brindley and Brown, 1980; Caillère et al., 1982; Bouchet et al., 2000). The wavelength of the major ray is shifted from 14.36 Å to 17.132 Å on the EG test. The diagram also shows a peak for K1 at the wavelength 12.243 Å confirming the presence of inter-stratified clay, probably illite-montmorillonite (Brindley and Brown, 1980; Caillère et al., 1982).
The results of the Hofmann and Klemen (1950) test on K1 and K2 are shown in Fig. 2. It can be seen that the samples exchanged with lithium and heated at 300°C does not inflate anymore after saturation with glycerol. This structural modification can be explained as an irreversible closing of intrafoliar due to the migration of the Li+ cations toward emptied octahedral cavities, characterizing the presence of montmorillonite clay.
Infrared spectroscopy: Inside the domain corresponding to the elongating vibration of the hydroxyl (3750-3500 cm-1), the spectrogram shows a large massive complex that reflects the diversity of the hydroxyl groups environment (AlAlOH, AlMgOH, AlFeOH, FeFeOH etc.) (Fig. 3). The remarkable bands around 3696 and 3620 cm-1 wavenumber confirm the presence of Kaolinite (Farmer, 1974). At low frequencies corresponding to the range 1000 to 600 cm-1, it is observed bands around 915, 890 and 795 cm-1. This can be attributed to the distorting vibrations of AlAlOH, AlFeOH and FeFeOH, respectively. This is characteristic of the presence of dioctahedral smectite. The other characteristic frequencies around the bands 1109 and 1017 cm-1 correspond to the distortion vibrations of the SiO (Fripiat, 1970; Famer, 1974).
|•||An intense and large endothermic peak around 130°C, corresponding to the starting point of the intra-sheets water|
|•||An endothermic accident of low intensity around 200°C, corresponding to the starting point of the hygroscopic water of associated minerals.|
|•||From 450 to 600°C, an outstanding endothermic peak corresponding to the deshydroxylation explained by the following chemical equation: 2 (OH) →O+H 2 O↑8.|
|Table 1:||Chemical composition in total rock of the studied samples|
|Fig. 1:||Comparison of X-rays patterns of K1 and K2 obtained by normal thin films and saturated EG|
|Fig. 2:||Study of Hoffmann-Klemen effect on K1 and K2 samples|
At 800°C, we also observe a relatively marked endothermic accident due to the emergence of an amorphous, followed by an exothermic peak which characterized the recrystallization toward 900°C (Greene, 1957). The position of the experimental peaks as described above (dehydration around 130°C and deshydroxylation between 450 and 600°C) corresponds to the phenomenon reported by several authors during the heating of the phyllosilicates 2:1 dioctahedrals (Poinsignon, 1977; Emmerich et al., 1999). In the case of the samples studied, the experimental peaks are probably cis-vacant montmorillonite clay, agreeing with the x-rays diffraction analysis (Emmerich et al., 1999; Vantelon, 2001).
|Fig. 3:||Infrared spectrograms of K1 and K2 obtained with diffuse reflection|
|Fig. 4:||Differential thermal analysis of K1|
|Fig. 5:||Differential thermal analysis of K2|
Quantitative mineralogy: It is noted that the samples of the deposits of Katiola are primarily made of inflating clays contrary to various deposits formerly highlighted through Cĉte dIvoire (Dorthe, 1984; Andji et al., 2001; Konan et al., 2001).
|Table 2:||Relative quantification of argillaceous minerals present in K1 and K2|
Indeed, the results show:
|•||For K1: 74.5% montmorillonite, with an inter-stratified clay (13.5), kaolinite (7%) and illite (5,4%).|
|•||For K2: 73.4% montmorillonite, kaolinite (23.5%) and a trace of illite (3.1%).|
These compositions could explain the difficulties experienced by Mangoros cooperative. The results of quantitative mineralogy are consigned in Table 2.
Due to their high capacity of water absorb to inflate; montmorillonite clays induces strong withdrawals during the drying of the potters manufactured products (Delineau, 1994).
Taking into account their composition, K1 and K2 clays lets predict large perspectives in the clayey materials valorisation in Cĉte dIvoire. These materials can be used in environment protection, for heavy metals immobilization (Nir et al., 1986; Carretero, 2002), in health science, cosmetic products and in all applications that use the properties of montmorillonites.
The experimental technique used for this study has shown that the studied sample K1 is composed of montmorillonite (74.5%) associated with inter-stratified clay (13.5%), kaolinite (7%) and illite (5.4%). The sample K2 is composed of 73.4% of montmorillonite 23.5% of kaolinite and 3.1% of illite.
The composition of the clay raw materiel explains the high rate of loss during the drying of potters products. Nevertheless, this raw materiel may be used in the cosmetic industry, in the environment protection and health science.
This study was done in the Laboratoire Environnement et Minéralurgie (LEM) of Nancy. We are grateful to the staff members of the LEM for their appreciate contribution to this work. We take this opportunity to thank the French department of foreign affairs for the financial support to this work.
- Andji, Y.Y.J., J. Sei, A. Abba Toure, G. Kra, D. Njopwouo, 2001. Mineralogical and physicochemical characterization of some clay samples of the site of Gounioube (Côte d’Ivoire). J. Soc. Ouest-Afr. Chim., 11: 143-166.
- Assaad, E., A. Azzouz, D. Nistor, A.V. Ursu and T. Sajin et al., 2007. Metal removal through synergic coagulation-floculation using an optimized chitosan-montmorillonite system. Applied Clay Sci., 37: 258-274.
- Carretero, M.I., 2002. Clay minerals and their beneficial effects upon human health. Applied Clay Sci., 21: 155-163.
- Cases, J.M., 2002. Natural minerals and divided solids: Methodology for understanding surface phenomena related to industrial uses and environmental problems. C.R. Geosci., 334: 585-596.
- Ghosh, D. and K.G. Bhattacharyya, 2002. Adsorption of methylene blue on kaolinite. Applied Clay Sci., 20: 295-300.
- Elkebrokk, B. and T. Saltnes, 2001. Removal of Natural Organic Matter (NOM) using different coagulants and lightweight expanded clay aggregate filters. Water Sci. Technol., 1: 131-140.
- Hizal, J. and R. Apak, 2006. Modeling of cadmium (II) adsorption on kaolinite-based clays in the absence and presence of humic acid. Applied Clay Sci., 32: 232-244.
- Konan, K.L., J. Séi, J.Y.Y. Andji, N.S. Soro, S. Oyetola, A.A. Touré and G. KRA, 2001. Study of some clay samples of the site of Sékoudé (Côte d’Ivoire). J. Soc. Ouest-Afr. Chim., 011: 181-196.
- Liang-Guo, Y., J. Wang, Y. Hai-Qin, Q. Wei, B. Du and S. Xiao-Quan, 2007. Adsorption of benzoic acid by CTAB exchanged montmorillonite. Applied Clay Sci., 37: 226-230.
- Montes, G.H., J. Duplay, L. Martinez and C. Mendoza, 2003. Swelling-shrinkage kinetics of MX80 bentonite. Applied Clay Sci., 22: 279-293.
- Mumin, M.A., M.M.R. Khan, K.F. Akhter and M.J. Uddin, 2007. Potential of open burnt clay as an adsorbent for the removal of Congo red from aqueous solution. Int. J. Environ. Sci. Technol., 4: 525-532.
- Nir, S., D. Hirsch, J. Navrot and A. Banin, 1986. Specific adsorption of lithium, sodium, potassium and strontium to montmorillonite: Observations and predictions. Soil Sci. Soc. Am. J., 50: 40-45.
- Pusch, R., 1992. Use of bentonite for isolation of radioactive waste products. Clay Miner., 27: 353-361.