THERMOLUMINESCENCE DOSIMETRY STUDIES OF INDUSTRIALLY IMPORTANT MINERALS CHAPTER-1 GENERAL INTRODUCTION

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1 THERMOLUMINESCENCE DOSIMETRY STUDIES OF INDUSTRIALLY IMPORTANT MINERALS CHAPTER-1 GENERAL INTRODUCTION 1.1 INTRODUCTION It has been more than 400 years since Robert Boyle incidentally discovered the thermoluminescence (TL) in diamonds. All through those years, it piqued scientist interest and curiosity and numerous studies were done for this phenomenon. Thermoluminescence had many different explanations during these years but in simplest and modern form, thermoluminescence can be defined as the emission of light from a semiconductor or an insulator when it is heated, due to the previous absorbed and stored energy from irradiation [1,2]. Because of numerous efforts of the scientists, thermoluminescence now has various application areas such as radiation dosimetry, age determination and geological researches. In today s evolving world, minerals are becoming more and more important for many industrial areas including radiation dosimetry, which is the most common and the most important application area of thermoluminescence. On the other hand, there was not enough research for minerals on its thermoluminescence properties. In light of the foregoing, the purpose of this thesis was drawn. Thus, in this study it was aimed to investigate the thermoluminescence properties of pure and irradiated minerals with different dosages. At the end of the study, the results of the characterization analysis and thermoluminescence readings were discussed. The main aim of the present study is the thermoluminescence of industrially important minerals. TL can be very useful tool in quality control in the selection of raw materials for ceramic tiles. The present minerals under study were collected from Bhor ghats, Sangamaner, Nasik and also from various ceramic industries at Morbi, Rajkot district, Gujarat state. Among the minerals collected from ceramic industry, the following eleven clay minerals; Ukraine Clay, White Soda, Ivory Soda, Potash, Snow White, China clay, Potash White, Quartz, Preform granuals, Mixed powder, Ceramic tile powder are selected to Thermoluminescence(TL) study. Powder X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermo Gravimetric Analysis (TGA), Inductively coupled plasma atomic emission spectroscopy (ICPAES) and Laser diffraction particle size analyzer used for the characterization of collected minerals. Three samples namely Preform granuals, Mixed powder and

2 Ceramic tile powder are the part of the pre final and final product of ceramic tiles are also subjected to TL measurement after irradiation. The natural minerals Amethyst, Calcite, Scolecite and Stilbite collected from Bhor ghats, Sangamaner, Nasik are considered for the studies of TL and XRD analysis. FTIR study was done for Calcite as it exhibits good TL. In ceramic tiles and sanitary ware industries, various types of minerals are mixed in appropriate quantities and ball milled for six to eight hours in distilled water, and then the obtained slurry is sieved to get appropriate particle size around fifteen micron are collected for further processes. The present TL study of minerals is intended to suggest the quality of the raw material at input stage of the ceramic tiles industry. TL dosimetric studies are done in case any accident like nuclear fallout. The present minerals mentioned above are mostly used as components in vitrified/ceramic tiles in turn the tile can be used as accidental TL Dosimetry to detect the quantum of radiation in a particular period. 1.2 MINERALOGY The planet on which we live can be seen as a large rock or, more precisely, as a large sphere composed of many types of rocks. These rocks are composed of tiny fragments of one or more materials. These materials are minerals, which result from the interaction of different chemical elements, each of which is stable only under specific conditions of pressure and temperature. From a chemical perspective, a mineral is a homogeneous substance. A rock is composed of different chemical substances, which, in turn, are components of minerals [3,4]. Mineralogy is the study of chemistry, crystal structure, and physical (including optical) properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. Early writing on mineralogy, especially on gemstones, comes from ancient Babylonia, the ancient Greco-Roman world, ancient and medieval China, and Sanskrit texts from ancient India and the ancient Islamic World. The modern study of mineralogy was founded on the principles of crystallography and to the microscopic study of rock sections with the invention of the microscope in the 17th century [5]. X-rays are used to determine the atomic arrangements of minerals and so to identify and classify them. The arrangements of atoms define the crystal structures of the minerals. Some very finegrained minerals, such as clays, commonly can be identified most readily by their 2

3 crystal structures. The structure of a mineral also offers a precise way of establishing isomorphism. The knowledge of atomic arrangements and compositions deduce the specific physical properties of minerals [6] and one may calculate how those properties change with pressure and temperature. The history of mineralogy is as old as man. The history of mineralogy has been written by special stones and gems. Faith, magic, science; mystic therapy, magic therapy, physical therapy; belief in extra-natural powers and belief in the action of matter, all these are intimately bound up with the life that stones and minerals, and gems, in particular, had in the mentality of our ancestors[7] Minerals A mineral is any naturally occurring homogeneous solid that has a definite chemical composition and a distinctive internal crystal structure. Minerals are usually formed by inorganic processes. Synthetic equivalents of some minerals, such as emeralds and diamonds, are often produced in the laboratory for experimental or commercial purposes. Although most minerals are chemical compounds, a small number (e.g., sulfur, copper, gold) are elements. The composition of a mineral can be defined by its chemical formula. The identity of its anionic group determines the group into which the mineral is classified. For example, the mineral halite (NaCl) is composed of two elements, sodium (Na) and chlorine (Cl), in a 1:1 ratio; its anionic group is chloride (Cl -)-a halide, so halite is classified as a halide. Minerals can thus be classified into the following major groups: native elements, sulfides, sulfosalts, oxides and hydroxides, halides, carbonates, nitrates, borates, sulfates, phosphates, and silicates. Silicates are the most commonly occurring minerals because silica is the most abundant constituent of the Earth's crust (about 59 percent). A mineral crystallizes in an orderly, three-dimensional geometric form, so that it is considered to be a crystalline material. Along with its chemical composition, the crystalline structure of a mineral helps determine such physical properties as hardness, colour, and cleavage [8]. 3

4 Rocks: Minerals combine with each other to form rocks. A rock is generally a natural solid composed of multiple crystals of one or more minerals. Although many rocks contain visible crystals of individual minerals, a rock itself does not have an overall crystalline structure. For example, granite consists of the minerals feldspar, quartz, mica, and amphibole in varying ratios. Rocks are thus distinguished from minerals by their heterogeneous composition [9]. A mere 100 of the several thousand known types of minerals constitute the main components of rocks. Clay Minerals: The term clay minerals refers to phyllosilicate minerals and to minerals which impart plasticity to clay and which harden upon drying or firing. In contrast, the term clay refers to 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 [10]. Based on the distinctions between the two terms made here, a clay mineral is a specific mineral which is a naturally occurring homogeneous solid with a definite chemical composition and an ordered atomic arrangement [8], in which atoms of these elements are organized into crystalline forms. Clay is mainly a size term which corresponds to minerals and nonminerals with a specific grain size range. Clay minerals are one of the major constituents of natural geomaterials (including soils and rocks) and occur abundantly in geosphere. They account for about 16 % by volume of the earth s upper 20 km surface. Ubiquitous presence of clay minerals makes their significant importance in multi-disciplinary science including ceramics (main raw material), soils and agronomy (used as nutrients and fertilizer), sedimentary petrology, civil engineering, clay chemistry, and economic geology [11]. The crystal structures, chemical compositions, particle surface properties, and size distributions of most clay minerals have been considerably revealed with the help of X-ray diffraction, nanoscale imaging (e.g., atomic force microscopy (AFM), transmission electron microscopy (TEM)), and other of modern analytical techniques. Clay minerals are mostly composed of oxygen, silicon, hydrogen, aluminum as well as calcium, sodium, potassium, magnesium, and iron [12]. Most clay minerals are composed of two basic 4

5 1.2.2 History of Minerals and Ceramic Tiles Kautilya said, Minerals are the wealth of a nation [13]. Minerals have been an important part of our society since the time of prehistoric man. Early humans carved tools out of minerals such as quartz. Pottery has been made of various clays since ancient times. Chloride, also known as the mineral halite, as been used in food preservation techniques for millions of years. Mining of useful minerals out of ores became widespread hundreds of years ago, a practice still in use today [14]. Ceramic are made by following mainly four steps, mixing, shaping, drying, firing. About 4,000 to 3,000 years B.C, clay was used as one of the basic ingredients to make ceramics in Egypt and Mesopotamia. As reported by Grim[15], extensive study of clay minerals started from early 1900s and use X-ray diffraction for the study of clay-sized minerals. Thereafter, more and more clay mineral structures were disclosed by X-ray diffraction and other advanced technologies. For example, Gruner [16] worked out the crystal structure of kaolinite. Hofmann et al [17] studied montmorillonite s crystal structure and proposed a model that featured an expanding structure. Grim et al. [18] studied a hydrous mica mineral and introduced a general term illite for micalike clay minerals. Today, most of the clay minerals structures have been identified with the aid of Xray diffraction[19,20]. The word ceramic comes from the Greek word keramikos. In Sanskrit ceramic means to fire or heat. A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous. The earliest ceramics were pottery objects made from clay, either by itself or mixed with other materials, hardened in fire. Later ceramics were glazed and fired to create a colored, smooth surface. Ceramics now include domestic, industrial and building products and art objects. In the 20th century, new ceramic materials were developed for use in advanced ceramic engineering; for example, in semiconductors.ceramic tiles of B.C shown in figure-1.1 and 1.2. India's very complex history involves repeated invasions by people from many different cultures Persians, Greeks, Arabs etc. and has a correspondingly complex ceramic history. Indian ceramics tended to be low temperature and unglazed until relatively modern times. Like the Middle East it had strong traditions of fired clay as architectural decoration. 5

6 Fig: 1.1 Wall tile 518 B.C.Iran Fig: 1.2 Maiolica tile of 16th century Italy 6

7 1.2.3 Mineral Identification Approximately 3,000 minerals exist in nature. Minerals differ from one another because each has a specific chemical composition and a unique three-dimensional arrangement of atoms within its structure. These differences result in a variety of physical properties, including the minerals' appearance, how they break, how well they resist being scratched, even how they smell, taste, and feel. All of these properties are equally useful. Some properties never change. These are the most useful for identifying a mineral and are called diagnostic properties. The following physical properties are diagnostic properties to identify minerals. Colour: The colour of minerals depends on the presence of certain atoms, such as iron or chromium which strongly absorb portions of the light spectrum. The mineral olivine, containing iron, absorbs all colours except green, which it reflects, so we see olivine as green. All natural minerals also contain minute impurities. Some minerals such as corundum get their colours from these impurities. Blue corundum (sapphire) is formed when small amounts of iron and titanium are dissolved in the solid crystal. Finally some crystals get their colour from growth imperfections. Smoky (black) quartz is a good example. Growth imperfections interfere with light passing through the crystal making it appear darker, or almost black. The colour of a mineral is one of its most obvious attributes, and is one of the properties that is always given in any description. Colour results from a mineral s chemical composition, impurities that may be present, and flaws or damage in the internal structure. Unfortunately, even though colour is the easiest physical property to determine, it is not the most useful in helping to characterize a particular mineral. Some minerals do have only a single colour that can be diagnostic, as for instance the yellow of sulfur. Streak: The colour of a mineral when it is powdered is called the streak of the mineral. Crushing and powdering a mineral eliminates some of the effects of impurities and structural flaws, and is therefore more diagnostic for some minerals than their colour. Streak can be determined for any mineral by crushing it with a hammer, but it is more commonly (and less destructively) obtained by rubbing the mineral across the surface of a hard, unglazed porcelain material called a streak plate. Luster: The luster of a mineral is the way its surface reflects light. Most terms used to describe luster are self-explanatory: metallic, earthy, waxy, greasy, vitreous (glassy), adamantine (or brilliant, as in a faceted diamond). It will be necessary only 7

8 to distinguish between minerals with a metallic luster and those with one of the nonmetallic lusters. A metallic luster is a shiny, opaque appearance similar to a bright chrome bumper on an automobile. Other shiny, but somewhat translucent or transparent lusters (glassy, adamantine), along with dull, earthy, waxy, and resinous lusters, are grouped as non-metallic. Cleavage: In some minerals, bonds between layers of atoms aligned in certain directions are weaker than bonds between different layers. In these cases, breakage occurs along smooth, flat surfaces parallel to those zones of weakness. In some minerals, a single direction of weakness exists, but in others, two, three, four, or as many as six may be present. Where more than one direction of cleavage is present, it is important to determine the angular relation between the resulting cleavage surfaces: are they perpendicular to each other or do they meet at an acute or obtuse angle. Fracture: When bonds between atoms are approximately the same in all directions within a mineral, breakage occurs either on irregular surfaces (splintery or irregular fracture) or along smooth, curved surfaces (conchoidal fracture), similar to those formed when thick pieces of glass are broken. Hardness: The hardness of any object is controlled by the strength of bonds between atoms and is measured by the ease or difficulty with which it can be scratched. Diamond is the hardest mineral, because it can scratch all others. Talc is one of the softest; nearly every other mineral can scratch it. We measure a mineral's hardness by comparing it to the hardnesses of a standardized set of minerals first established by Friederich Mohs in the early nineteenth century, or with the common testing materials that have been calibrated to those standards. The Mohs Hardness Scale is a relative scale. This means that a mineral will scratch any substance lower on the scale and will be scratched by any substance with a higher number. Crystal Shape: When minerals form in environments where they can grow without interference from neighboring grains, they commonly develop into regular geometric shapes, called crystals, bounded by smooth crystal faces. The crystal form for a given mineral is governed by the mineral's internal structure, and may be distinctive enough to help identify the mineral. For example, quartz forms elongated, six-sided prisms capped with pyramid-like faces; galena and halite occur as cubes; and garnets develop 12- or 24-sided equidimensional forms. Interference from other mineral grains during growth may prevent formation of well-formed crystals. The result is shapeless masses 8

9 or specimens that developed only a few smooth crystal faces. This type of specimen is much more common than well-formed crystals. Specific Gravity: The specific gravity of a substance is a comparison of its density to that of water. To compare the specific gravity of any two minerals, simply hold a sample of one in your hand and "heft it," i.e. get a feeling for its weight. Then heft a sample of the other that is approximately the same size. If there is a great difference in specific gravity, you will detect it easily. Other Properties: There are a few other tests that can be used to differentiate one or more common minerals. Some of these should be used with great caution. Magnetism - A few minerals are attracted to a magnet or themselves capable of acting as magnets (the most common magnetic mineral is magnetite). Because these are so rare, this property helps narrow the possibilities drastically when trying to identify an unknown specimen. Feel - Some minerals, notably talc and graphite, feel greasy or slippery when you rub your fingers over them. The greasiness occurs because bonds are so weak in one direction That your finger pressure alone is enough to break them and to slide planes of atoms past neighboring atomic layers. Taste - Geologists use as many senses as possible in describing and identifying minerals. Taste is one of the last tests to be conducted, because some minerals are poisonous. Some minerals taste salty-most notably halite (salt). Sylvite, a mineral similar in all other properties to halite, tastes bitter. Taste is thus a diagnostic property because it distinguishes between these minerals. Reaction with Dilute Hydrochloric Acid - This is actually a chemical property rather than a physical attribute of a mineral. Minerals containing the carbonate anion (CO3)2- effervesce ("fizz") when a drop of dilute hydrochloric acid is placed on them. Carbon dioxide is liberated from the mineral and bubbles out through the acid, creating the fizz. This test is best performed on powdered minerals. Calcite (calcium carbonate) will effervesce readily in either massive or powdered form, but dolomite (calcium-magnesium carbonate) reacts best as a powder Classification of ceramics Ceramics are classified on various bases as follow: 9

10 (a) Prevailing divisions: Ceramics are broadly grouped in three divisions as (1) clay products, (2) Refractory and (3) glasses. (b) Classification based on application: Fig: 1.3 shows the classification of Ceramics on the basis of application. (c) Classification based on structure: Applications of Ceramics: Ceramics are used in an array of applications: Compressive strength makes ceramics good structural materials (e.g., bricks in houses, stone blocks in the pyramids) High voltage insulators and spark plugs are made from ceramics due to its electrical conductivity properties. Good thermal insulation has ceramic tiles used in ovens and as exterior tiles on the Shuttle orbiter Some ceramics are transparent to radar and other electromagnetic waves and are used in radomes and transmitters Hardness, abrasion resistance, imperviousness to high temperatures and extremely caustic conditions allow ceramics to be used in special applications where no other material can be used Chemical inertness makes ceramics ideal for biomedical applications like orthopaedic prostheses and dental implants Glass-ceramics, due to their high temperature capabilities, leads to uses in optical equipment and fiber insulation 1.3 TILES MANUFACTURING PROCESS: Following four operations are required in the manufacturing process of tiles: (1) Preparation of clay: The plastic, strong or pure clay is taken and is made free from any impurity such as grit, pebbles etc. Such clay is then converted into powder in crushing mill and then mixed in pug mill. (2) Moulding: Prepared clay is placed in mould which represent the pattern or shape in which the tile is to be formed. Moulding may be done either with the help of wooden or machine moulding or by potter's wheel moulding 10

11 Ceramic Materials Cements Abrasives Glasses Glass Glasses Clay Products Structura l White wares Refractory Advanced Ceramics Fire clay Silica Basic Special Fig: 1.3 Classification of ceramics based on Application 11

12 (3) Drying of tiles: The moulded tiles are then arranged in such a manner so as to have free circulation of air. Generally drying under a shade prevents warping and cracking of tiles due to rain and sun. Generally two stage drying is carried out. In the first stage after 2 days, irregularity of tiles is removed with a flat wooden mallet. Again for another two days they are stacked on edge to dry for about 3 days or so. (4) Burning: After drying of tiles, tiles are well burnt in a typical stalkote kiln for accommodating about tiles to achieve the hardness and strength property of tiles. The period taken is about 3 days Good tiles should have following properties: (1) Tiles should be of regular shape and size. (2) It should possess uniform colours. (3) It should be free from cracks, bends etc. (4) It should be strong, hard and durable. (5) It should be well burnt. (6) It should have a compact and even structure when its section is taken out. (7) Thickness of tiles varies from 5 mm to 15 mm as per the requirement. 1.4 THERMOLUMINESCENCE Thermoluminescence as mentioned by McKever and et al., is one of the processes in Thermally Stimulated Phenomena [21]. In a general view, thermoluminescence is a temperature stimulated light emission from a crystal after removal of excitation. Nevertheless, microscopically, it is much more complicated. In this chapter, the thermoluminescence mechanism will be discussed in detail. With the developing technology, thermoluminescence has various application areas such as, radiation dosimetry, age determination and geology History of Thermoluminescence The studies on thermoluminescence go back to the seventeenth century, when scholars like Johann Sigismund Elsholtz, Robert Boyle and Henry Oldenburg conducted experiments on minerals to see their radiation due to heating. George Kaspar Kirchmaier, who regarded the phosphorus as a green stone powdered and mixed with water and glows when heated, and Nathaniel Grew, who used the name Phosphorus metallorum [22], are other scientists who showed interest in the concept. 12

13 Among the eighteenth century researchers, Dufay is the first to be acknowledged for his findings on thermoluminescence. He referred to lighting as a kind of burning. He worked on many materials, primarily chlorophane, and found out that too much heating would lead to loss of thermoluminescence of the material. A famous scientist, Canton brought Dufay s studies to a new level, by raising the temperature of phosphorus even further and discovering a new type of light, which he referred to as the thermoluminescence of artificial phosphorus [23, 24]. Leading scientists, De Saussure and Thomas Wedgwood need to be mentioned in the thermoluminescence studied of the eighteenth century. The former recognized three types of stones which luminesced on heating: (1) those containing sulphur, which burned in the free air, (2) those which absorb the light and then emit it, like the diamond, and (3) those which do not require air and will luminesce under hot water, like dolomite and fluorspar. He declared that the intensity of the color of the fluorspar is an indicator for the level of thermoluminescence. The latter conducted a study on the thermoluminescence and triboluminescence, lighting as a result of friction. His findings showed that it was not possible to claim a solid relation between the patterns of two types of luminescence. Studies on thermoluminescence continued in the nineteenth century. Researcher, Heinrich claimed that almost all substances could emit light, provided that they are in powder form and subject to moderate heating. Another researcher Theodor von Grotthus dealt specifically with the fluorspar, and showed resemblance between thermoluminescence and essence; both are made of positive and negative parts. Later, scientist David Brewster opposed to Grotthus, arguing that the luminescence property cannot always be regained on exposing the minerals to light. Other researchers who studied thermoluminescence in the nineteenth century are Pearsall, who tried to find a relation between colour and thermoluminescence; Specia, who invalidated Pearsall s findings; Napier, who experimented on the chalks; Wiedmann and Schmitt, who attributed the thermoluminescence characteristic to cathode rays Applications of Thermoluminescence The thermoluminescent materials used in the industry have three major areas; radiation dosimetry, age determining and geology. 13

14 The radiation dosimetry measures the dose that is absorbed by the sample that is exposed to irradiation. Radiation dosimetry has three subgroups; personnel dosimetry, medical dosimetry and environmental dosimetry. Personnel dosimetry is used in areas where the personnel are exposed to radiation; nuclear reactors, radiotherapy wings in hospitals and nuclear powered submarines. Medical dosimetry intends to measure the effects of a TLD that is placed into the appropriate places within human body [25]. Environmental dosimetry deals with the radiation present in the environment due to humankind. Due to applications like nuclear power stations, waste disposals, usage or processing of nuclear fuels and disastrous nuclear power plant malfunctions introduce high levels of radiation into the environment. Therefore, it become essential to monitor the radiation released to the environment continuously [26,27]. 1.5 ORIGIN OF RESEARCH PROBLEM Now a day ceramic tiles and ceramic ware are becoming basic requirement of people in the world. The people demand various types of high quality ceramic tiles and other ceramic products. Also high demand of ceramic tiles and sanitary product in estate market in the world is increasing day by day. Ceramic tiles and other ceramic material are useful in industries, scientific research, medical science, electronics components, space science etc. In the early days, the tiles were hand-made, each tile was hand-formed and handpainted, thus each was a work of art in its own right. Ceramic tile was used almost everywhere on walls, floors, ceilings, fireplaces, in murals, and as an exterior cladding on buildings. In fact most modern houses throughout use Ceramic tiles in every vital area of the premise. Ceramic tiles are also the choice of industry, where walls and floors must resist chemicals. And the Space Shuttle never leaves Earth without its protective jacket of high-tech, heat resistant tiles. Morbi, (Figure 1.4) the most promising ceramic tiles manufacturing hub of India, is a city located in Saurashtra region of Gujarat. More than 400 units manufactures more than 70% of total ceramic production in India with total installed capacity of 1.8 million Sq.ft. tiles per day.the raw materials used to manufacturing ceramic tiles are 14

15 mainly from Gujarat, Rajasthan and Andhra Pradesh mines. The following raw materials are used to produce ceramic tiles. Ukraine Clay, White Soda, Ivory Soda, Potash, Snow White, China clay, Potash White, Quartz, etc. The present TL study of minerals is intended to suggest the quality of the raw materials at input stage of the ceramic tiles industry. TL dosimetry studies are done in case any accident like nuclear fall out these ceramic tiles fixed in the toilet, bathroom, and flooring, may be used to get total radiation received from the accident day to sample analyzed day. The minerals under study were collected from Bhor ghats, Sangamaner, Nasik (Figure 1.5) also from various ceramic processing industries in Morbi. Rajkot District, Gujarat. Over all fifteen verities of the minerals were collected and selected to TL study, XRD, TGA, FTIR, Laser diffraction Particle size analysis and Induction coupled plasma atomic emission spectroscopy (ICPAES). In ceramic tiles and sanitary ware the manufacturing process is mixing of various type of minerals in appropriate quantities are taken and ball milled for six to eight hours in distilled water the obtained slurry is sieved to get appropriate particle size around 15 micron are collected for further processes.the present TL study of minerals is intended to suggest the quality of the raw material at input stage of the ceramic tiles industry. TL dosimetry studies are done in case any accident like nuclear fall out these ceramic tiles fixed in the toilet, bathroom, and flooring, may be used to get total radiation received from the accident day to sample analyzed day. 1.6 METHODOLOGY OF THE THESIS The Clay minerals were characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectrometry (FTIR) analysis. Thermo Gravimetric Analysis (TGA) was used for examination of the thermal properties of minerals. Dosimetric properties of the minerals were investigated by Thermoluminescence (TL) technique. The natural minerals Amethyst, Calcite, Scolecite and Stilbite collected from Bhor ghats, Sangamaner, Nasik were characterized by XRD, FTIR, TGA and TL studies. Laser diffraction particle size analyzer used for the characterization of some of collected minerals. Three minerals were considered for the study of Induction Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). At the end of the study, the results of the characterization analysis and thermoluminescence readings were discussed. 15

16 Fig. 1.4 Map indicating Morbi, Gujarat State, India Fig.1.5 Map indicating Sangamner, Nashik, Maharashtra State, India 16

17 1.7 ORGANIZATION OF THESIS This thesis consists of seven chapters. The following is a brief summary of each chapter content. Chapter one covers the general introduction on mineralogy, Ceramics, Ceramic tiles and basics of thermoluminescience process. In this part, the purpose and the methodology of the study are presented. Chapter two is dedicated to the Thermoluminescence phenomena and Radiation dosimeters. The first part devoted to basics of luminescence, types of luminescence and thermoluminescence. In addition, this part includes the application areas of thermoluminescence. In the second part of this chapter, general introduction, properties of radiation dosimeters and its applications are discussed. Chapter three gives a brief description of experimental techniques used in present study. This describes the instruments: TL glow curve recorder, XRD, TGA (Thermal Gravimetric Analysis), Laser diffraction particle size analysis, FTIR and ICPAES used for the characterization of collected minerals. Chapter four includes the materials under study and the sample preparation of collected natural minerals and clay minerals from different sources. The materials, the details of initial treatment procedures as well as the analysis methods and conditions employed for characterization of samples are included at this part. Chapter five embraces the results of the experiments stated in Chapter 3. These results include the outputs from characterization analysis as well as thermoluminescence measurements Chapter six deals with the TL dosimetric work using Sr-90 beta source. The first part deals with TL growth and discussion of glow curves for few samples which show good TL. The second part deals with TL decay and discussion of glow curves for few samples which show good TL. Also growth and decay graphs are presented. Finally, Chapter seven is dedicated to the conclusions to be drawn from this study and recommendations Each chapter is followed by the list of references and cross references. 17

18 REFERENCES [1]. Furetta, C, Handbook of Thermoluminescence,Claudio Furetta, World Scientific, Singapore (2003) [2].Pagonis, V., Kitis, G., Furetta, C.: Numerical and Practical Exercises in Thermoluminescence. Springer Science+Business Media, Inc., New York (2006) [3].Rocks and Minerals, Encyclopædia Britannica, Inc, (2008) [4].The complete Encyclopedia of Minerals, Petr Korbel,Milan Novak, Grange Books PLC, UK,(2001) [5].Needham, Joseph, Science and Civilization in China, 3, 637 (1986). [6].Ramsdell, Lewis S. Encyclopedia Americana: International Edition, 19,166,New York: Americana Corporation, (1963) [7].Bandy, Mark Chance and Jean A. Bandy, De Natura Fossilium,New York, George Banta Publishing Company,(1955). [8].Dana, James D., Hurlbut, Cornelius S.; Klein, Cornelis. eds. Manual of Mineralogy (20 ed.). John Wiley & Sons Inc. ISBN (1912). [9].Chisholm, Hugh, ed "Petrology". Encyclopædia Britannica (Eleventh ed.). Cambridge University Press, (1911). [10].Guggenheim, S., Martin, R.T., Definition of clay and clay mineral: joint report of the AIPEA nomenclature and CMS nomenclature committees. Clays and Clay Minerals 43, and Clay Minerals 30, [11].Hurlbut, C.S. and Klein C. (1977) Manual of Mineralogy, Ninteenth Edition, John Wiley & Sons, New York. [12].Bergaya,F,Theng,B.K.G. and Lagaly,G. Handbook of Clay Science, Developments in Clay Science, Vol. 1, 2006 Elsevier Ltd (2006). [13].Mitchell, J.K. and Soga, K. (2005) Fundamentals of Soil Behavior, 3rd. John Wiley & Sons, Inc., Mondol, N.H., Jahren, J., Bjorlykke, K., and Brevik, I. (2008) [14].Chatterjee.K.K., Uses of industrial minerals, rocks and freshwater, Nova Science Publishers, Inc., New York, 2009 ]. [15].Willi.P and Renata.K, Acta Geodyn. Geomater., 6,1(153), ,(2009). [16].Grim, R.E. The history of the development of clay mineralogy. Clays and Clay Minerals, 36, , (1988). [17].Gruner, J.W. The crystal structure of kaolinite. Z. Kristallogr, 83, 75-88, (1932). [18].Hofmann, U., Endell, K. and Wilm, D. Kristalstrucktur und Quellung von Montmorillonit, Z. Kristallogr, 86, , (1933). 18

19 [19].Grim, R.E., Bray, R.H., and Bradley, W.F. (1937) The mica in argillaceous sediments. American mineralogist,22, [20].Moore, D. M. and Reynolds, R. C,X-Ray Diffraction and the Identification and Analysis of Clay Minera ls. Oxford University Press, New York,(1997). [21].McKeever, S., Moscovitch, M., Townsend, P.: Thermoluminescence Dosimetry Materials: Properties and Uses. Nuclear Technology Publishing, England (1995) [22].Chen, R., McKeever, S.: Theory of Thermoluminescence and Related Phenomena. World Scientific Publishing Co. Pte. Ltd., Singapore (1997) [23].Harvey, E.: A History of Luminescence: From the Earliest Times Until Dover Phoenix Editions, USA (2005) [24].Schauer, D., Brodsky, A., Sayeg, J.: Handbook of Radioactivity Analysis, Second Edition. Academic Press, Great Britan (2003) [25].McKeever, S.W.S,Thermoluminescence of solids, Cambridge University Press, Cambridge (1983) [26] Nambí,K.S.V, Thermoluminescence: Its understanding and applications, Aprovado Para Publicaçao em, Março,(1977). [27].Gad Shani, Radiation Dosimetry: Instrumentation and Methods, Second edition, CRC Press, Boca raton,london,(2000).. 19