[PDF] COMPOSITIONAL FEATURES AND INDUSTRIAL APPLICATION OF

View - Download COMPOSITIONAL FEATURES AND INDUSTRIAL APPLICATION OF

Previous PDF

Next PDF

Rjeas Research Journal in Engineering and Applied Sciences 1(5) 327-333 Rjeas

© Emerging Academy Resources (2012) (ISSN: 2276-8467) www.emergingresource.org 327
COMPOSITIONAL FEATURES AND INDUSTRIAL APPLICATION OF IKERE

KAOLINITE, SOUTHWESTERN NIGERIA

Abel O. Talabi, Oladimeji L Ademilua and Oluwatoyin O. Akinola

Ekiti State University,

Faculty of Science, Department of Geology, Ado-Ekiti

Corresponding Author: Abel O. Talabi

ABSTRACT

Kaolin is an industrial mineral which remains chemically inert over a relatively wide pH range. It has varied

applications in ceramics, paper, paints, refractories, fiberglass, plastics, cosmetics and pharmaceutical

industries. It could serve as road and building construction materials. In view of the highlighted properties of

kaolinite, the compositional features of Ikere kaolinitic clay were investigated with a view to determining its

industrial applications and provide a guide for further economic assessment of the deposit. As part of the study

approach, twenty five representative samples of the kaolinite were analyzed for chemical composition using X-

ray fluorescence analytical technique at Nigeria Institute of Science Laboratory Technology Ibadan (NISLT)

while the granulometric analysis and other physical properties assessment were undertaken at Ekiti State

Ministry of Works, Ado-Ekiti. Result of the granulometric analysis indicates that the Ikere kaolinite deposit

consists of high percentage of clay/silt size particles with low shrinkage value (ca. 3.25 N/mm2) which makes it

suitable as construction materials. The kaolinite is moderately plastic with specific gravity value ranging

between 2.58 and 2.68 and a mean value of 2.61. The chemical analysis of the sample indicates the dominance

of SiO2 and Al2O3 over other oxides with an average value of 50.14% and 34.41% respectively. Mean values of

other oxides; Fe2O3, MnO, MgO, CaO, Na2O, K2O, TiO2 and P2O5 are 3.3.0%, 0.04%, 1.77%, 6.22%, 0.72%,

0.39% and 0.49% respectively. Significantly therefore, the Ikere kaolinite has been shown to be of medium

plasticity and toughness and could be useful raw material in pottery, paper production and refractory.

©Emerging Academy Resources

KEYWORDS: Kaolinite, Granulometric Analysis, Refractory, Plasticity and Toughness.

INTRODUCTION

Kaolinite is a clay mineral, part of the group of industrial minerals with the chemical composition Al2Si2O5 (OH) 4. It is a layered silicate mineral with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina i.e. structurally composed of silicate sheets (Si2O5) bonded to aluminum oxide/hydroxide layer Al2 (OH) 4 called gibbsite layers and repeating layers of the mineral are hydrogen bonded together (Bear, 1965). Gibbsite is an aluminum oxide mineral that has the same structure as these aluminum layers in kaolinite. The silicate and gibbsite layers are bonded together with only weak bonding existing between these silicate/gibbsite paired layers (called s-g layers). The weak bonds between these s-g layers cause the cleavage and softness of this mineral. Pure kaolinite is a product of intense weathering . It is common in tropical soils and is the second most abundant clay mineral in ocean sediments (Grim, 1968) Kaolinite shares the same chemistry as the minerals halloysite, dickite and nacrite. The four minerals are polymorphs as they have the same chemistry but different structures. All the minerals were derived from the chemical alteration of aluminum rich silicate minerals such as feldspar. However, they could be found as sedimentary deposits as well as hydrothermal alteration product of rocks containing a high proportion of alumino-silicate minerals. Kaolinite, is an industrial mineral that has been put into diverse uses in our society. Prominent among these are in the production of papers, ceramics, cosmetics, medicine and porcelain. It is also used as filler for paint and plastics since it is relatively inert and is long lasting. However, the greatest demand for kaolinite is in the paper industry to produce a glossy paper such as is used in most magazines. Clay mineral has strong affinity for water molecules. When a little clay is added to water, slurry forms because the clay distributes itself evenly throughout the water. This property of clay is used by the paint industry to disperse pigment (color) evenly throughout paint. Without clay to act as a carrier, it would be difficult to evenly mix the paint base and color pigment. A mixture of clay and a little water results in a mud that can be shaped and dried to form a relatively rigid solid. Potters and the ceramics industry exploit these properties to produce plates, Research Journal in Engineering and Applied Sciences (ISSN: 2276-8467) 1(5):327-333 Compositional Features and Industrial Application of Ikere Kaolinite, Southwestern Nigeria 328
cups, bowls, pipes, and so on. Environmental industries use both these properties to produce homogeneous liners for containment of waste. Another important property of clay minerals is the ability to exchange ions with the charged surface of clay minerals. These ions can be attracted to the surface or taken up by these minerals without disrupting its structure. The property of clay minerals that causes ions in solution to be fixed on clay surfaces or within internal sites applies to all types of ions, including organic molecules like pesticides. Clays can be an important vehicle for transporting a widely dispersing contaminants from one area to another. An industrial application of kaolinite is dependent on many factors including mineralogical composition, geology, chemistry and physical properties. In almost every instance, kaolinite has different properties and thus must be fully tested and evaluated to determine its uses. Industrial requirement for kaolinite in Nigeria is estimated to be well over 360,000 metric tons while annual current production stood at 110,000 metric tons from local production, a supply gap of over

250,000 metric tons exist annually (Oaikhinan,

1999). Several studies and survey such as Kehinde

and Aliyu (1989) have proving the existence of huge local deposit of kaolinite in Nigeria. Kaolinite is useful for different industrial application due to its physical and chemical properties. In general, the distribution, the distribution of the uses of kaolinite is as follows; paper industry (45%), refractory and ceramics (31%), fiberglass (6%), cement (6%) rubber (5%), paint (3%) and other (4%) Murray, (2002). In view of the fact that kaolinite is a unique industrial mineral and a functional ingredient in many industrial applications as well as the need to meet Nigeria kaolinite industrial requirement warrants evaluating the physical and chemical properties of Ikere - Ekiti kaolinitic deposit to determine its industrial potential.

LOCATION/GEOMORPHOLOGY

The study area is located on charnockitic bedrock in the North-Eastern part of Ikere town at about 2km along Ikere-Emure road on Latitude 7o00'N and

Longitude 5o15'E (Figure 1).

The study area enjoys tropical climate marked by alternating raining and dry season. The annual temperature ranging from 28oC to 30 oC and a mean annual rainfall of 1500mm with high relative humidity of about 75 percent favours tropical weathering. The vegetation signature of the study area has been altered due to prolong human activities like bush burning and agricultural practices. The undulating topography coupled with tropical climate and rocks that are highly suceptible to weatheringresult into formation of different soil horizons (Figures 2 & 3) which describes each of the layers that occur in the soil. Horizon formation (horizonation) is a function of a range of geological, chemical, and biological processes and occurred over a long periods of time. Soils vary in the degree to which horizons are expressed and it is defined in most cases by obvious physical features, colour and texture being chief among them. The horizons may be described in absolute terms, particle size distribution for texture and in relative terms to the surrounding material i e, 'coarser' or 'sandier' than the horizons above or below. Soil generally consists of visually and texturally distinct layers. However, as shown in (Figure 3) Ikere kaolinite has three main horizons (A, B and C). The "A" horizon is brownish in colour with littered plant remains in relatively decomposed form. The "B" horizon is finer in texture than "A" horizon and has a light brown colour while "C" horizon is grey to white colour resulting from lack of pedogenic activity.

MATERIALS AND METHODS

Systematic field mapping of the exposed kaolinite deposit at a road cut along Ikere-Emure road was carried out in order to establish the local geology of the deposit and decides on sampling method appropriate for the study. For this study, an existing geological map of Ekiti Figure 4 adapted from (Talabi & Tijani, 2011) was used. The rock underlying the kaolinite deposit is principally charnockitic rocks. Lateritic capping are a common occurrence in many places occupied by the kaolinite deposit. A simple field test was conducted on the kaolinite by adding small amount of water to powdered sample and the mixture uniformly stirred until a plastic stage is attained.This result was affirmative for a further evaluation of the kaolinite. As part of further methodological approach, the exposed surface of the kaolinite was scraped using cutlass, shovel and geologic harmmer as appropriate on the various horizons of the kaolinite. Subsequently, vertical sampling at interval of one meter was adopted as there was no much variations in the kaolinite laterally. Five vertical representative profiles were selected from the kaolinite outcrop.

Five (5) samples each weighing about 1.0kg from

each profile were taken at vertical interval of one metre with the aid of a geological hammer. All samples were carefully labelled and put in sac bags for the laboratory analyses. The samples were sun dried and pulverised using clean agate motar and pestle. The prepared samples were analysed for chemical composition and some physical characteristics (particle size distribution, Atterbergs limits and specific gravity). Analytical results were compared with ideal kaolin, the UK kaolin standards and some clay deposits in Nigeria.

RESULTS AND DISCUSSION

X-ray Diffraction: The X-ray diffractogram of Ikere clay deposit (figure 5) revealed the presence of kaolinite, quartz and illite with kaolinite dominating Research Journal in Engineering and Applied Sciences (ISSN: 2276-8467) 1(5):327-333 Compositional Features and Industrial Application of Ikere Kaolinite, Southwestern Nigeria 329
the mineralogy. The semi quantitative mineralogical composition was determined based on relative peak intensities and reflects to a reasonable extent the mineralogical characteristics of kaolinite.

Particle Size Analysis: The particles size

distributions of Ikere clay (Table 2) revealed a moderate percentage of clay and silt size particles (>44.5wt (%) passed 75 ȝ sieve). Grain size is important in assessing clay material for characteristics required for various industrial applications. The grain size composition of clay controls ceramic strength, shrinkage, paper filling and paper coating and its glossiness (Aref, 2002). Forbus et al, (1993), Veglio et al, (1993) and Ryan, (1979) specified that fine-grained minerals such as kaolinite are very useful industrially, in making paper, pulp filler, coating and also as an essential material in pharmaceutical and ceramic Industries. The grain size of kaolinite for example is said to range from below

1µm - 50µm (Heinskanen, 1996). Ikere kaolinite

deposit falls in this category and could be usefull especially in ceramic and paper industries. However, beneficiation of Ikere kaolinite through intercalation with urea can cause reduction in grain size that can fcilitate its requirement in other industrial applications (Al-Shameri & Rong, 2009).

Specific Gravity and Atterberg Limits: Result of

specific gravity determination of Ikere kaolinite using Density bottle method indicates a range of 2.58-2.68 and an average value of 2.61(Table 3). The average specific gravity of 2.61 supports the fact that Ikere clay deposit is kaolin based on the classification of mineral (Gary, 2008). Atterberg limits designate the relative ease with which a clay soil can be deformed and is used to describe the degree of firmness of the clay soil mass. Atterberg limits include amongst others; the liquid limit, plastic limit and shrinkage limit. In this study, liquid limit ranges between 23-39, plastic limit ranges between 12.5-22.0, shrinkage limit ranges between 2.23-3.96 with plasticity index ranging of 10.5-18.0 (Table 3). Liquid limit and plasticity index are used to classify fine-grained soils. All liquid limit values in this study are <100%, classifying the clay as inorganic clay. Plasticity index ranging from 10.5-18.0 indicates the clay is of medium plasticity. This observation was further supported using Casagrande, (1948) plasticity chart (Figure 6) further support this assertion. Thus Ikere clay could easily be moulded and satisfy requirements for pottery making. The Ikere clay has averge shrinkage limit of 3.25 N/mm2. This value is lower than the average (5.6N/mm2) reported by Nigerian Building and Road Research Institute (NBRRI) and Mesida (1978) on some deposit. However, average plasticity index of 3.25 N/mm2 compares favourably with 3.0N/mm2 recommended for construction of bungalow and one storey building (Aribisala, 1989). This observation supports that Ikere kaolinite could be used as building construction material.

Chemical Composition: The Chemical composition

of clay deposit is important in ascertainig its industrial characteristics. Table 4 shows the chemical composition of Ikere clay with average chemical values in wt (%) of SiO2 (49.85), Al2O3 (34.1), Fe2O3 (3.31), MnO (0.04), MgO (1.17), CaO (6.23), Na2O (0.77) and K2O (0.39) rrespectively. Other oxides in average wt (%) include TiO2 (2.02) and P2O5 (0.47).

For comparison purpose as shown in (Table 5),

values of chemical composition for SiO2 and Al2O3 are almost similar to China clay and composition data of kaolinite from other previous research works. However, Ikere clay is characterized by high content of Fe2O3 and TiO2 compared to values from other research works and is responsible for the brownish colouration of the deposit. The colour can be improved upon (i.e. increased whiteness) by adopting various physical and chemical processes like sieving, magnetic separation (Veglio et al, 1996), leaching with various chemicals like oxalic and other organic acids (Ambikadevi & Lalithambika, 2000). Furthermore, Ikere clay with correlation coefficient of about 0.97 for most industrial specifications (Table 6) could be applied in such industries except for its high Fe2O3 and CaO contents. The Fe2O3 content can be rduced through beneficiation in which samples are treated with organic acids in presence of a fermented medium (De Mesquita et al, 1996).

CONCLUSION

Compositional features and industrial application of Ikere kaolinite was evaluated based on mineralogy, chemical composition and physical characteristics of the deposit with a view to determining its suitability as an industrial raw material. From the study, it is obtained that Ikere clay deposit is predominantly kaolinite but with high Fe2O3 and CaO contents. It is rare for any single clay deposit to completely satisfy all the manufacturing requirement of its derivative product. Obviously, different sets of criteria are important to the production of any specific blend for a specific industry. Therefore, Ikere kaolinite can find application in refractory, pottery, paper and paint industry with beneficiation of the deposit where necessary Table 1: Mineralogical composition of Ikere kaolinite (wt. %)

Mineral Percentage composition

Kaolinite 64

Quartz 28

Illite 8

Research Journal in Engineering and Applied Sciences (ISSN: 2276-8467) 1(5):327-333 Compositional Features and Industrial Application of Ikere Kaolinite, Southwestern Nigeria 330
Table 2: Particle Size Distribution of Ikere Kaolinite

A, B, C, D and E (average of five samples)

Table 3: Statistical Summary of physical tests (Ikere kaolinite) Table 4: Statistical Summary of chemical parameters (Ikere kaolinite - wt%)

Parameter Min. Max. Mean Median Stdev.

quotesdbs_dbs9.pdfusesText_15

[PDF] industrial automation and robotics a.k. gupta pdf

[PDF] industrial automation and robotics book

[PDF] industrial automation and robotics book pdf download

[PDF] industrial automation and robotics book pdf free download

[PDF] industrial cities in karnataka

[PDF] industrial clusters in karnataka

[PDF] industrial fdm 3d printer

[PDF] industrial hand sanitizer

[PDF] industrial safety and risk management

[PDF] industrial safety and risk management book

[PDF] industrial safety and risk management ppt

[PDF] industrial safety management hazard identification and risk control

[PDF] industrial sources of air pollution

[PDF] industrialization and climate change

[PDF] industrialization and climate change pdf