ANALYSIS OF PROPERTIES OF KAOLIN DEPOSITS IN NIGERIA

ABSTRACT

This study considered the mineralogical, elemental composition in form oxides and engineering properties such as particle size, specific gravity, bulk density; water content and atterberg limits of two kaolin deposits in Kpankorogi in Edu Local Government of Kwara State and in Ijero-Ekiti in Ijero-Ekiti Local Government Area, Ekiti State.This is  with a view to assessing their potentials for Various industrial applications. The analyses includes X-Ray Diffraction (XRD and X-Ray Fluorescence(XRF). It was observed that the kaolin sample from Kpankorogi is dominated by Quartz and the one from Ijero- ekiti by Orthoclase. The result of the chemical analysis indicates the presences of SiO₂, Al₂O₃, Fe₂O­₃, TiO₂, MnO, CaO, MgO, K₂O, Na₂O, CuO, ZmO, Cr₂O₅, V₂O₅ and Sc₂O₃. The X RD In particular, shows that Kpankorogi kaolin contains Quartz and Kaolinite while Ijero- Ekiti contains in addition to kaolinite,s orthoclase and Muscovite. Considering the possible applications of the two kaolin deposits, it was observed they do not meet the required standards completely in all instances.    

TABLE OF CONTENTS

Title Page                                                                                                                   i

Certification                                                                                                    ii

Dedication                                                                                                                 iii

Acknowledgement                                                                                                   iv

Abstract                                                                                                                     v

Table of Content                                                                                                       vi-vii

List of Tables                                                                                                    viii

List of Figures                                                          xi                                                   

 CHAPTER ONE                                                                                            

 1.0    Introduction                                                                                               1

 1.1   Aim and Objectives of the Study                                                          2

 1.2   Scope and Limitation of the Study                                                       3

 1.3   Research Justification                                                                             3

1.4    Problems Statement                                                                                 3

 CHAPTER TWO     

  2.0 Literature Review                                                                               4

  2.1 Historical Background of the Study                                                  4

  2.2 Properties of Kaolin                                                                                5

  2.3 Uses of Kaolin                                                                                6

 CHAPTER THREE

 3.0 Materials and Methods                                                                    8

 3.1 Description of the Study Areas                                              8

 3.2 Method of Samples Collection                                                     8

 3.3 Laboratory Analyses                                                                                 12      

 3.3.1 Moisture Content                                                                         12

 3.3.2 Bulk Density Determination                                                   13

 3.3.3 Specific Gravity Determination                                                   13

 3.3.4 Grain Size Analyses                                                                     15

 3.3.5 Atterberg Limit                                                                        17

 3.3.6.1 Liquid Limit                                                                                     17

 3.3.6.2 Plastic Limit                                                                              18

 3.3.6.3 Shrinkage Limit                                                                    19

 3.3.7 X.R.D. Analysis                                                                             20

 3.3.8 X.R.F. Analysis                                                                        22

 CHAPTER FOUR

•   Results And Discussion                                                                23

4.1  Properties of Kpankorogi and Ijere-Ekiti Kaolin Deposits                    23

 4.2   Water Content Distribution                                                           23

 4.2   Bulk Density                                                                                   24

 4.3   Specific Gravity                                                                            24

 4.4   Atterberg Limits                                                                               24

 4.5     Sieves Analyses                                                                   25

 4.1.6   X-ray Diffraction                                                                         26

 4.6     X-ray Fluorescence                                                                                          28

CHAPTER FIVE

 5.0 Conclusion and Recommendation                                                       31

 5.1 Conclusion                                                                                  31

 5.2 Recommendation                                                                               31

       References                                                                                             33    

LIST OF TABLES

Table 4.1:     Engineering and physical properties of the samples              31

Table 4.2:     Grain Size Analysis of the samples                                32      

Table 4.3:     Chemical composition of the Samples                              33

Table 4.4:     Mineralogical components of the Samples                             33

Table 4.5      Major elemental oxides tested by kaolin sample compared

with  chemical and industrial specifications                    34

LIST OF FIGURES

Fig. 3.1:      Map of Nigeria Showing Kwara and Ekiti States       12

Fig. 3.2:      Map of Ekiti State indicating the study Area A                        

Fig. 3.3:      Map of Kwara State indicating the Study Area B                                

Fig. 4.1:         X-ray Diffractogram of Kpankorogi Kaolin Sample             35

Fig.4.2:          X-ray Diffractogram of Ijero-Ekiti Kaolin Sample              36

CHAPTER ONE

1.0                  Introduction

       Kaolin is a clay rock and part of the group of industrial minerals with the chemical composition (Al₂Si₂0₅ (OH)₄.

It is a layered silicate mineral with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet alumina i.e. structurally composed of silicate sheet (Si₂O­₅) bonded to aluminum oxide/hydroxide layer Al₂ (OH)₄ called gibbsite layers and repeating layer of the mineral are hydrogen bonded together. (Rost, 1992; Bish, 1993; Klein and Kuribut, 1993; Slivka, 2002).

        Kaolin is a plastic raw material, particular consisting of clay mineral kaolinite. In systematic mineralogy, Kaolin ranks among phyllosilicates, which are stratified clay minerals formed by a network of tetrahedral and octahedral layers. Phyllosillicates are classified into the main groups according to the type of layers, inter-layer contents, charge of the layers and chemical formulas. Besides kaolinite groups, serpentine, halloysite, pyrofylite, mica and montmorillonite groups also ranks among phylllosillicates. Group of kaolinites includes di-octahedral mineral with two layers and one silica (SiO₄) tetrahedral layer and one aluminum (Al₂(OH)₄) octahedral layer. The layers are bonded together by sharing oxygen anion between Al and Si together, these two layers are called platelets (Pauk,et al.,1962;Stejskal, 1971., Duda et al., and Hurlbut, 1993).

Kaolinite shares the same chemistry as the mineral halloysite, dickeite and necrite.  The four minerals are polymorphs as they have the same chemistry but different structures. All the minerals were derived from chemical alteration of aluminum rich silicate minerals, such as feldspars. However, they could be found as sedimentary deposits as well as hydrothermal alteration product of rocks containing a high of alumino-silicate minerals.

            Kaolin is formed under acidic conditions through weathering or hydrothermal change of feldspars, and to a lower extent also other weathered kaolin deposits, kaolin clay or may be a compound of kaolinite, sandstones and olitic ironstones, and  less frequently also of pegmatiteand hydrothermal deposit. The most significant kaolin deposits were formed through intensive weathering of rock rich in feldspars (granite, arkoses, certain types of ortho-gneisses and misgmatites).             

 Millions years ago, original material was decomposed by weathering, giving rise to kaolin and silica combined with higher or lower amounts of admixtures.(Bernard, el al; 1992).  

1.1   Aim and Objectives of the Study

 Aim of this study is to determine the suitable industrial application of kaolin from location investigated.

To achieve the above stated aim, the following objective will be carried out:

1. determination of mineralogical composition of the kaolin deposits

    ii      determination of the chemical/oxide composition of the deposits

    iii     determination of the physical and engineering properties of the kaolin deposits.

1.2   Scope and Limitation of the Study

The purpose of this project covers two deposits, the Kpankorogi and the Ijero-Ekiti kaolin deposits. Samples were collected from each of the deposits for oxide analyses, mineralogical analyses as well as the determination of the engineering and physical properties. The numbers of samples are limited due to cost constraint. A sample is collected from each of the deposits for both the oxides and mineralogical analyses. This particular study does not include reserve estimation, but this is recommended for future workers.