EFFECTS OF TEMPERATURE AND ADDITIVES ON FIRE CLAY (IVA VALLY COAL MINE, ENUGU STATE)

CHAPTER ONE

INTRODUCTION

1.1     BACKGROUND OF STUDY

Fire Clay is a naturally occurring material composed primarily of fine-grained minerals, which is generally plastic at appropriate water contents and will harden when dried or fired. They have varying chemical composition depending on both the physical and chemical changes in the environment where fire clay deposits are found. . Fire clay is a very fine grained, unconsolidated rock matter, which is plastic when wet, but becomes hard and stony when heated. It has its origin in natural processes, mostly complex weathering, transported and deposited sedimentation within geological periods. Clay is composed of silica (SiO2), Alumina (Al2O3) and water (H2O) plus appreciable concentration of oxides of iron, alkali and alkaline earth, and contains groups of crystalline substances known as clay minerals such as quartz, feldspar and mica (Folaranmi 2009). Clay is used in various fields such as geology, chemistry, soil science, engineering and ceramic technology.

During firing of fired clay brick, a series of transformation occurs which determine the final properties of the brick product. The main factors involved in manufacturing bricks are the type of raw materials, fabrication method, drying procedure, firing temperature and firing profile. These factors will affect the quality of the final product. However, the durability and strength of bricks are related to their microstructure and mineralogy. In unfired clay bricks, the strength and water permeability are related to the size and shape of the particles present and the forming process, but upon heating, the nature of the mineral comprising the mass has a very important influence because of the chemical reactions and partial fusing which occur then. The porosity in brick unit depends on the type of clay used in manufacturing and temperature of firing. According to the porosity of the brick influence on its compressive strength, water absorption and permeability. During the sintering process in the brick manufacturing process, stable initial raw materials transform into complex compounds at high temperatures. New compounds are also formed due to chemical reactions that take place. These compounds have impacts on the stability of the material due to the decrease or increase in the volume of the system. A study showed that vitrification of ceramic material is an important factor that influences the quality and physical properties of the end product such as strength and permeability.

 FOR THE FULL COPY OF MATERIAL, CLICK TO CONTACT US TO PLACE ORDER AND MAKE PAYMENT. Please call us on +234(0)8085670139 or 08069479446. Email: researchnet@yahoo.com. Please call us on +234(0)8085670139 or 08069479446. Email: researchnet@yahoo.com

Tell Friends about this topic