Physico-Chemical and Mineralogical Characterization of Two Clay Materials of the Far North Region of Cameroon (Makabaye, Maroua)

To contribute to the valorization of local materials, the physico-chemical and mineralogical characterization of two clay materials MJ and MN collected in the Mayo Tsanaga river which crosses the Makabaye district of Maroua (Cameroon) was carried out. For this purpose, various methods of characterization have been used, namely granulometric analysis, Atterberg limits, X-ray fluorescence spectrometry and X-ray diffraction. It is apparent from the granulometry that the clay materials studied titrate 33.77% of clays for MJ against 44.13% for MN. The plasticity indices Ip with values IpMJ = 19.27% and IpMN = 23.4% place the materials in the plastic domain and offer them the possibility to being shaped into objects. The chemical composition of the MJ and MN materials reveals that the silicon oxide SiO2, the aluminumoxide Al2O3 and iron oxide Fe2O3 are their main constituents. The X-ray diffraction of the MJ and MN materials shows that they consist mainly of quartz with associated kaolinite, illite, montmorillonite, perlialite, dickite, nacrite, amesite, albite, brookite and anorthite. In addition to these, 2/1 minerals such as muscovite, nontronite, glauconite, and phlogopite are also identified in the MJ material. The peaks of sanidine, microcline and gismondine are also found in the MN material. The materials being rich in clay minerals 2/1 can be valorized in the adsorption and the absorption of the oils and greases and in the waterproofing of the grounds. The presence of quartz, kaolinite and illite is undoubtedly favorable for the manufacture of ceramic products in terracotta. These products will be obtained at a relatively lower temperature due to illite, feldspars and iron minerals that provide vitrification during firing by forming eutectics. The aluminosilicate amorphous phases contained in the How to cite this paper: Yanné, E., Oumarou, A.A., Nde, B.D. and Danwé, R. (2018) Physico-Chemical and Mineralogical Characterization of Two Clay Materials of the Far North Region of Cameroon (Makabaye, Maroua). Advances in Materials Physics and Chemistry, 8, 378-386. https://doi.org/10.4236/ampc.2018.89025 Received: March 15, 2018 Accepted: September 17, 2018 Published: September 20, 2018 Copyright © 2018 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access


Introduction
Clays are more or less hydrated, aluminosilicates; majority of which belong to the phyllitic silico-aluminates group [1]. These materials which dominate the 2-μm fraction of soils are an integral part of our daily lives. This is how they are found from the white layers of the paper on which we write, to the storage of harmful waste that we want to confine through cosmetics, tires, paints and building materials [2]. Their enormous external surface compared to their volume makes them privileged materials for catalysis, the retention of toxic or the supports of composites.
Clay materials exist in almost all regions of Cameroon [3]. In the Far North Region, clay soils are mainly used for the manufacture of different pottery items and building materials such as bricks. These activities, practiced by craftsmen during the dry season, bring them finances to meet their needs.
The efficient and rational use of these materials is most often limited by the low durability and mechanical resistance of their products. This is compounded by the fact that the mineral and chemical compositions of these abundant clay materials are unknown which makes it difficult to improve on the types and yields of the products manufactured from these clays. Without knowledge of chemical and mineralogical composition, it is difficult, for example, to know if a clay is fusible or refractory. The aim of this project therefore was carried out, the mineral and chemical composition of some clays of the Far North Region of Cameroon.
To do this, two representative clay materials MJ and MN, which are superimposed, were sampled in Maroua town in the Far North Region of Cameroon.
The chosen zones represent areas of high concentration of activities that employ clay the confection of pottery or construction materials. Chemical and mineral composition as well as granulometric analysis and the Atterberg limits were carried out on these materials. The results of this research will go a long way to contribute to the enrichment of the limited data base on clay materials in Cameroon.
The results of the work will be used to feed a database to support the start-up of industrial projects for local clay materials. The long-term wish is that this experimental and scientific approach, applied to a current raw material, contributes to the valorization of local materials and to sustainable development.

Materials
For this work, two representative clay materials MJ and MN were sampled in the Mayo Tsanaga river in Maroua town in the Far North Region of Cameroon. The chosen zone represents area of high concentration of activities that employ clay for the confection of pottery or construction materials. The clay material was located 70 cm deep below the sand layer. Maroua is located on latitude 10˚34'83''N and on longitude 14˚17'34''E and is 414 m above sea level. The MJ sample is brownish yellow (Munshell Code 10YR 6/6) while the MN sample is black (Munshell Code N2.5/). One of the major reasons for the choice of these clays is that the reserves are so enormous that they can satisfy an industrial demand.

Granulometric Analysis
It reflects the determination of the weight proportions of particles contained in the clay materials according to their sizes. Wet sieving of samples and the sedimentation of the fraction less than 100 µm were carried out according to French standards NF P18-560 [4].

Determination of the Atterberg Constant
Atterberg constant was determined by passing the clay material through a 400 μm aperture using the mechanical Casagrande apparatus according to the French standard NF P94-057 [5].
This constant determines the water content W which characterizes the following change: Solid → Plastic: W p Plastic → Liquid: W l The plasticity index Ip of the material was then determined from the Equation

X-Ray Fluorescence Spectrometry
The chemical composition of the clay materials was determined by X-ray fluorescence spectrometry using the Panalytical AXIOS PW4400 spectrometer. The molten pearl method was used. The beads were obtained from the dissolution of the materials in lithium tetraborate (Li 2 B 4 O 7 ) and homogenized at 1150˚C.

X-Ray Diffraction
X-ray diffraction was obtained using a diffractometer suitable for the characterization of polycrystalline plane samples, the X'PER PRO MDP diffractometer from Panalytical. The scanned angular range is between 5 and 70˚ in 2θ (angle of incidence). The copper Kα1 radiation (wavelength = 1.540598 Å) used was produced at a voltage of 40 kV and an intensity of 40 mA. The MN material is therefore richer in clay minerals than the MJ material, even though they have the same amounts of silt. Generally, the more a material is rich in fine fraction, the more it requires water to pass from a solid paste to a plastic paste and from it to a liquid paste [7]. In other words, the material will tend to retain more water between its particles, which will cause a relatively long drying time. As a result, it will take more energy to dry products made from MN material [8]. Table 1 presents the results of the Atterberg limits of the samples.

Atterberg Limits
These results show that the MJ material is less plastic than the MN material.
The MJ and MN materials can resist flow under its own proper weight up to moisture contents of 35.8% and 46.6% respectively. However, the plastic deformation, corresponding to its normal consistency (between 15% and 40%), requires less than 16.53% water for MJ and 23.2% water for MN. These results (plasticity index 19.27% and 21.5%) show that these materials are plastics [9].
This explains why the quantity of water they retain without becoming fluid is high. These results are in agreement with the results of the granulometric tests presented in Section 3.1.

Chemical Analysis
The results of the chemical analysis expressed as mass percentages of the oxides of MJ and MN materials are presented in Table 2.   [14]. The relatively high potassium oxide content relative to other alkali metal oxides is a favorable factor for illitization and a decrease in the maturation temperature of ceramics that could be elaborated from these materials [15]. These ceramics will naturally be colored red because of the presence of iron between 800˚C and 1100˚C [16]. Table 3 illustrates the analysis of X spectra using PDF files while Figure 2 and     A similar peak in the material MN is represented by a dome, characteristic of a mineral with a lower degree of crystallinity: such a peak denotes the presence of a poorly crystallized or amorphous kaolinite which does not have a microstructural organization [19]. Montmorillonite and illite also present domesat 14 Advances in Materials Physics and Chemistry and 10 Å, which are indicative of poor crystallinity.

X-Ray Diffraction of MJ and MN Samples
The 2/1 clay minerals have been used in the adsorption and absorption of oils and greases and also in the waterproofing of soils [20]. Quartz, kaolinite and illite are favorable for the manufacture of terracotta ceramic products. These products are obtained at a relatively lower temperature because of the presence of illite, feldspars (albite and anorthite) and iron minerals which provide vitrification by the formation of eutectics [21]. Amorphous minerals, especially aluminosilicates, are potential materials to produce cements and geopolymer concretes [22].