The clay in the locality of Sangaré-Paul referred to as SP, has been the subject of a mineralogical and physical characterization in order to assess the potential use in the field of ceramics. Firing experiments were carried out on experimental briquettes at temperatures of 900 °C, 1000 °C and 1100 °C after which physical tests and mineralogical analyzes were made on the cooked products. The results obtained from the mineralogical analyses show that the clay in the locality of Sangaré-Paul contains kaolinite, illite, quartz and feldspar, and when cooked, the presence of a new crystal phase is detected. From the granulometrical and physical tests, the material has a particle size spread with a plasticity index greater than 20%. Its activity is less than 0.75. It is kaolinite sandy clay with a low plasticity. The hydrogen potential (pH) measurement shows the weakly basic character of this clay. The technological parameters of experimental briquettes show that the percentage of water absorbed is less than 15%. The linear withdrawal of all experimental briquettes presents values less than or equal to 10%. The values of the mechanicals resistances of the briquettes increase globally with the temperature not exceeding 10 MPa for the bending, but reaching 38 MPa for the compression. All these parameters, except the linear withdrawal, present optima temperature at 1100 °C. The clay material of Sangaré-Paul is suitable for the manufacture of bricks and tiles at 1100 °C.
Clays have been used by man since the beginning of time. The natural abundance and immediate availability of clays explain their great uses over time. The peculiarity of this material is its capacity to have a plastic state with appropriate levels of water [
The clay materials used for the production of ceramics are often complex natural mixtures of minerals whose granulometry and physicochemical properties are highly variable [
The main objective of this work is to study the technological ability of this material for the manufacture of ceramic products for wide dissemination and sustainable local development. This study is a scientific contribution in the knowledge and characterization of industrial minerals which contributes to the promotion of local materials in Cameroon.
Clay samples were collected from a well located at latitude 9.285126˚ North and longitude 13.455767˚ East. About 2.0 kg of each sample was collected and placed in small polythene bags. 1.0 kg of each sample was dried, pulverized and sieved before analysis. Documentary studies [
The ENDECOTTS sieve series, a densimeter, a pycnometer, X-ray diffraction and infrared spectrometry were used to study the particle size as well as the physical and chemical properties of the material.
Mineralogical analyzes were performed using X-ray diffractometry (XRD) and infrared spectroscopy (IR). XRD was performed according to the protocol of the Laboratory of Geology and Sediment Environment (AGES) of the University of Liege in France. The data were recorded using a Brucker D8-Advance type diffractometer, and identification of the crystalline phases with DIFFRAC plus Release software 2000-EVA 6.
From the exploitation of the granulometric curve (
Granulometric analysis results show that the clay material is actually rich in clay and sand. The coefficient of uniformity being quite important, the grain size curve is much spread. The clay material is therefore good to be used in the manufacture of ceramic products. Indeed the grain size of a material for the manufacture of earth bricks must be spread [
The clay test results that allowed the determination of the Atterberg limits, the
apparent density, the actual density, the volume of methylene blue and pH are given in
From
Liquidity limit ωL (c/o) | 30.63 |
---|---|
Plasticity limit ωP (c/o) | 9.21 |
Plasticity Index Ip (c/o) | 21.42 |
Apparent density (g/cm3) | 2.12 |
Real density (g/cm3) | 2.42 |
Volume of methylene blue (ml) | 20 |
pH | 8.1 |
for the manufacture of clay bricks [
Examining the total powder diffractogram (
Then the metakaolin obtained is characterized by a lack of order at great distance in the arrangement of the constituent elements of its solid [
The increase of the sintering temperature (1100˚C) leads to the disappearance of the spinel phase and the appearance of a high mullite content as shown by the SP1-1100˚C and SP1-1000 diffractograms with the multiplication of the main lines of mullite between 1000˚C and 1100˚C. Mullite is an aluminum silicate that forms at high temperature and low pressure [
Quartz and feldspars are present on all diffractograms obtained at different sintering temperatures tested. The melting point of quartz (1700˚C) and that of potassium feldspars (1300˚C) is much higher [
The results of the infrared spectrometry analysis are shown in
The quality control tests carried out are designed to evaluate certain properties such as color, bulk density, mechanical flexural strength, compressive strength and linear shrinkage, loss of cooking mass and water absorption rate.
Technological parameters | Temperature | ||
---|---|---|---|
950˚C | 1000˚C | 1100˚C | |
Colour (Munsell Charter) | Clear yellowish 7.5Y 9/2 | Clear yellowish 7.5Y 9/2 | Dark yellowish 7.5Y 9/4 |
Cohesion | Good | Good | Very good |
Sound | Light metallic | Metallic | Metallic |
Linear shrinkage (c/o) | 1.5 | 2.5 | 10 |
Mass loss (c/o) | 7.76 | 7.83 | 8.04 |
Mass density (g/cm3) | 1.87 | 1.92 | 2.06 |
Water absorption (c/o) | 14.06 | 12.24 | 6.38 |
Resistance to flexion (MPa) | 3.34 | 5.02 | 9.76 |
Resistance to compression (MPa) | 19.23 | 21.53 | 37.44 |
To obtain bricks and even tiles of good quality as suggested by the diagram of Wrinkler and Niesper [
From the graph presented in
The scientific knowledge acquired on the natural materials and on the manufactured specimens makes it possible to justify the use of the Sangaré-Paul clay materials in the coarse field of ceramic and construction materials. Indeed sintering found at 1100˚C shows the sizzling and fusing nature of the natural material. In addition, the ideal particle size distribution for the manufacture of the fired bricks, the mechanical performance comparable to that of certain concretes and tiles, and the low mass loss and the rate of water absorption in accordance with the brick production criterion show the potential use of this clay material in coarse ceramics. The Sangaré-Paul clay is suitable for the manufacture of bricks and tiles at a temperature of 1100˚C.
The authors declare no conflicts of interest regarding the publication of this paper.
Nchare, M., Desire, E.O.B., Wang, L. and Sarki, B. (2018) Mineralogical and Physicochemical Characterization of Clay in the Sangaré-Paul Locality (North Cameroon), in Order to Assess the Potential Use in the Field of Ceramics. Open Journal of Inorganic Chemistry, 8, 71-80. https://doi.org/10.4236/ojic.2018.83006