CHAPTER FOUR
4.0 RESULTS AND DISCUSSION
4.1 PROPERTIES OF KAOLIN SAMPLES
The samples collected from two sampling locations, that is, the kpankorogi and Ijero-Ekitii were analyzed so as to enable their characterization.
The properties determined include atterbergs limits, Bulk density, specific gravity, moisture content, sieves analysis, mineralogical chemical properties.
The sample from kpankorogi is referred to as sample A and that of Ijero- Ekiti referred to as sample B.
4.1 WATER CONTENT
For sample A, the water content is 26% and sample B is 18%. As it is shown in table 4.1
4.2 BULK DENSITY
The bulk densities obtained are as follows: Sample A has a bulk density of 1.54g/cm3 while Sample B is 1.67g/cm3 as show in table 4.1. These are generally low bulk density values, however, the value for sample B approximately falls within the range recommended for by Hassan (2001), for dense fire bricks (1.7-2.1g/cm3)
4.3 SPECIFIC GRAVITY
The specific gravity of sample A is 2.5 while that of sample B is 2.6 as it show in table 4.1. According to Gary (2008), for a material to be designated to be kaolin and not kaolinitic soil, its specific gravity must be 2.61. Sample A falls short of this specification while sample B more or less meets the specification. Therefore it is only sample B that can be strictly referred to as kaolin while sample A can be referred to as kaolinitic soil.
4.4 SIEVES ANALYSES
The particle size distribution of the samples is shown in the table 2. The two samples show similar distribution however, sample seen to be finer having a larger proportion (49.2%) passing the 0.075mm sieve as against sample B with 33.5% passing through as it show below in table 4.2. Samples is thus, more suitable for use either as paper filler or for coating.
4.5 ATTERGERG LIMITS
The Atterberg limits are presented in table 4.1. The liquid limit for sample A is 53.5% while that of sample B is 43%. For the plastic limit, it is 37.4% for Sample A and 16.4% for Sample B. Consequently, the plasticity indices are as follow:
Sample A is 16% while that of sample B is 26.6%. For the shrinkage limit, Sample A is 27% while that of Sample B is 30%.
The liquid limit for both samples is <100%. This indicates that the clay can be classified as inorganic clay. The plasticity indices of sample A and sample B indicates medium plasticity which suggests that the clay can moulded. Thus the studied samples can be suitable for pottery making.
4.6 X –RAY DIFFRACTION
The result of the x- ray diffraction tests carried out are presented by table 4.4 and figure 1 and 2.
From the table 4.4, Sample A contains both Kaolinite and Quartz with Quartz dominating the mineralogy. On the other hand, Sample B contains orthoclase muscovite and kaolinite. In the case of Sample B orthoclase dominates. The quantitative mineralogical composition was determined based on relative peak intensities.
4.6 X-RAY FLUORESCENCE
The result of the oxide analysis is presented in the table 4.3. Elemental oxides found in the samples are SiO2, Al2O3, Fe2O3, TiO2, MnO, CaO, MgO, K2O, Na2O, CuO, ZnO, Cr2O5, V2O5 and Sc2O3, Table 4.5 shows the chemical requirements and industrial specification for kaolin. SiO2 of both samples can be used in refractory bricks, ceramics, Al2O3 meet the requirement for refractory bricks, ceramics, and coating, TiO2 meets the range that can be used in refractory bricks, rubber, ceramics, and brick clay, CaO content meets the requirement in refractory brick, rubber, ceramics and bricks clays, for K2O only Sample A meets the requirement for both ceramics and paper coating industries.NaO2 for both Sample A and B meets the requirement in refractory bricks, rubber, ceramics, paper coating and brick clay industries. While the remaining oxides that is CuO, ZnO, Cu2O5, Sc2O3, do not meets the requirement for and of the considered industrial and economic applications. Considering the fact both the Kpankorogi and Ijero- Ekiti do not wholly meet the specified standards, it is therefore imperative for kaolin from the study areas to be beneficiated to enhance their properties and make them suitable for various industrial uses.
