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XRF & XRD Analysis Principle

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XRF & XRD Analysis Principle

  1. 1. XRF & XRD AnalysisXRF & XRD Analysis PrinciplePrinciple BY: Muhammad Nohman Mahmud Sr.AM (QC) Presented to the Quality Control /Assurance staff of Bestway Cement Group
  2. 2. History of X-rays:History of X-rays: History of X-Rays :History of X-Rays : •   X-rays were discovered in 1895 by the German scientist Wilhelm Conrad RoentgenX-rays were discovered in 1895 by the German scientist Wilhelm Conrad Roentgen (1845-1923).(1845-1923). • Working with a cathode ray tube (CRT) in a dark room he discovered a white spot on aWorking with a cathode ray tube (CRT) in a dark room he discovered a white spot on a photographic film after development. As he did not know what kind of rays came from thephotographic film after development. As he did not know what kind of rays came from the CRT he called those rays X-rays. Later he put his wife’s hand between the CRT and theCRT he called those rays X-rays. Later he put his wife’s hand between the CRT and the photographic plate and after developing the photographic plate he saw the structure of hisphotographic plate and after developing the photographic plate he saw the structure of his wife’s hand, including finger bones and the wedding ring, on the photographic plate. Sowife’s hand, including finger bones and the wedding ring, on the photographic plate. So the application of X-rays for medical diagnostics were apparent from the beginning. Forthe application of X-rays for medical diagnostics were apparent from the beginning. For his discovery he was awarded thehis discovery he was awarded the first Nobel Prize for physics.first Nobel Prize for physics. • The properties of these X-rays were investigated and by 1912 the principles of diffractionThe properties of these X-rays were investigated and by 1912 the principles of diffraction physics and reciprocal space were developed by Rontgen, von Laue, Ewald,Sommerfeldphysics and reciprocal space were developed by Rontgen, von Laue, Ewald,Sommerfeld and Brentano in Munich, Germany. It was in 1914 that father and son Bragg (Leeds andand Brentano in Munich, Germany. It was in 1914 that father and son Bragg (Leeds and Manchester, UK) introduced the crystallography. The principles of powder diffractometryManchester, UK) introduced the crystallography. The principles of powder diffractometry were described in 1916 by Debye and Sheerer (Gottingen, Germany). In that same yearwere described in 1916 by Debye and Sheerer (Gottingen, Germany). In that same year the structure of LiF was reported. Hull (New Haven, USA) published the structure of -Fethe structure of LiF was reported. Hull (New Haven, USA) published the structure of -Fe in 1917.The first principles of size-strain analysis were published in 1918 by Sherrer.in 1917.The first principles of size-strain analysis were published in 1918 by Sherrer.
  3. 3. DiscovererDiscoverer
  4. 4. History of X-rays:History of X-rays: • From 1917 to 1919 Brentano developed in Zürich, Switzerland the ideas of the bentFrom 1917 to 1919 Brentano developed in Zürich, Switzerland the ideas of the bent monochromator and focusing optics,monochromator and focusing optics, but only in 1947 the first commercialbut only in 1947 the first commercial powder diffractometer was introduced by Philips in the USApowder diffractometer was introduced by Philips in the USA , after earlier, after earlier developments of Le Galley (1935), Friedman (1945, Washington, USA) and Parrish anddevelopments of Le Galley (1935), Friedman (1945, Washington, USA) and Parrish and Gordon (1947, USA).The Powder Diffraction File (PDF) from Dow Chemical Company,Gordon (1947, USA).The Powder Diffraction File (PDF) from Dow Chemical Company, started in the late 1930s, was continued from 1950 onwards by the former Jointstarted in the late 1930s, was continued from 1950 onwards by the former Joint Committee for Powder Diffraction Systems (JCPDS), now calledCommittee for Powder Diffraction Systems (JCPDS), now called InternationalInternational Centre for Diffraction Data (ICDD),Centre for Diffraction Data (ICDD), and issued yearly the PDF database on cardsand issued yearly the PDF database on cards and in books and later on micro-fiche, tape and now CD-ROM. Starting with a 1000and in books and later on micro-fiche, tape and now CD-ROM. Starting with a 1000 patterns, that database now contains a number of patterns in the order of magnitude ofpatterns, that database now contains a number of patterns in the order of magnitude of 100000 and is the most important database in X-ray powder diffraction. The100000 and is the most important database in X-ray powder diffraction. The development of calculation machines and computers in the 1950s and 1960s broughtdevelopment of calculation machines and computers in the 1950s and 1960s brought about the full potential of the application of single crystal and powder diffractometry,about the full potential of the application of single crystal and powder diffractometry, which also allowed a great deal of automation. In the 1980s and 1990s new X-raywhich also allowed a great deal of automation. In the 1980s and 1990s new X-ray optics, like parallel beam collimators, multi-crystal monochromators, graded mirrors andoptics, like parallel beam collimators, multi-crystal monochromators, graded mirrors and capillary lenses were introduced, enabling an even larger range of applications.capillary lenses were introduced, enabling an even larger range of applications.
  5. 5. What are X-rays:What are X-rays: • WHATWHAT AREARE X-RAYS?X-RAYS? • X-rays can be seen as electromagnetic (EM) waves with their associated wavelengths,X-rays can be seen as electromagnetic (EM) waves with their associated wavelengths, or as beams of photons with associated energies. Both views are correct, but one or theor as beams of photons with associated energies. Both views are correct, but one or the other is easier to understand depending on the phenomena to be explained. Otherother is easier to understand depending on the phenomena to be explained. Other electromagnetic wave includes light, radio waves, and gamma rays. The wave lengthselectromagnetic wave includes light, radio waves, and gamma rays. The wave lengths of x-rays are in the range from 0.01 to 10nm, which corresponds to energies in theof x-rays are in the range from 0.01 to 10nm, which corresponds to energies in the range from 0.125 to 125 keV. This region is bounded on the short wavelength side byrange from 0.125 to 125 keV. This region is bounded on the short wavelength side by Gamma rays and on the long wavelength side by Ultra-Violet radiation. The wave lengthGamma rays and on the long wavelength side by Ultra-Violet radiation. The wave length of X-rays is inversely proportional to its energy, according to E*λ= hc, E is the energy inof X-rays is inversely proportional to its energy, according to E*λ= hc, E is the energy in keV and λ the wavelength in nm. The term is the product of Planck’s constant and thekeV and λ the wavelength in nm. The term is the product of Planck’s constant and the velocity of light and has, using keV and nm as units, a constant value of 1.23985.The X-velocity of light and has, using keV and nm as units, a constant value of 1.23985.The X- ray wavelength is given in (nm) or, more commonly in the crystallographic world, in theray wavelength is given in (nm) or, more commonly in the crystallographic world, in the older unit Angstrom (Å).1 Å = 0.1 nm 1 nm = 10 Åolder unit Angstrom (Å).1 Å = 0.1 nm 1 nm = 10 Å
  6. 6. What are X-rays:What are X-rays:
  7. 7. X-rays Safety:X-rays Safety: • RADIATIONRADIATION • All kinds of radiation exists in and around us at all times. The question arises what effectAll kinds of radiation exists in and around us at all times. The question arises what effect radiation has on us.radiation has on us. • But first we have to answer the question what is radiation.But first we have to answer the question what is radiation. • Radiation is phenomenon, which can be described as having wave properties, but canRadiation is phenomenon, which can be described as having wave properties, but can also be described as particles. Some are ionising.also be described as particles. Some are ionising. • For some types of radiation we prefer the wave description, like Electro-magnetic wavesFor some types of radiation we prefer the wave description, like Electro-magnetic waves (photons), other radiation is best described as an emission of particles from an atom or(photons), other radiation is best described as an emission of particles from an atom or nucleus, like electrons, protons, neutrons or complete atomic nuclei.nucleus, like electrons, protons, neutrons or complete atomic nuclei. • A lot of radiation types are harmless, but the more energetic radiation is dangerousA lot of radiation types are harmless, but the more energetic radiation is dangerous because of its ionising nature and other properties, see the next section.because of its ionising nature and other properties, see the next section. • WARNING X-RAYSWARNING X-RAYS AREARE DANGEROUS!!!DANGEROUS!!! • THEYTHEY CANCAN CAUSECAUSE SERIOUSSERIOUS PERSONALPERSONAL INJURYINJURY IFIF SAFETYSAFETY • INSTRUCTIONSINSTRUCTIONS ANDAND RECOMMENDATIONSRECOMMENDATIONS AREARE NOTNOT FULLYFULLY CARRIEDCARRIED OUTOUT • PROPERTIESPROPERTIES OFOF SHORTSHORT WAVELENGTHWAVELENGTH ELECTRO-MAGNETICELECTRO-MAGNETIC RADIATIONRADIATION
  8. 8. X-rays Safety:X-rays Safety: • The following properties make short wavelength (high-energy) Electro-magneticThe following properties make short wavelength (high-energy) Electro-magnetic radiation a dangerous phenomenon:radiation a dangerous phenomenon: • _ They are not physically detectable by the human senses like smell, taste, touch or_ They are not physically detectable by the human senses like smell, taste, touch or visionvision • _ They are always transmitted in a straight line_ They are always transmitted in a straight line • _ They travel at the speed of light_ They travel at the speed of light • _ There is almost no refraction by means of normal lenses or prisms_ There is almost no refraction by means of normal lenses or prisms • _ They penetrate in and through matter_ They penetrate in and through matter • _ They are ionising (generate charged particles)_ They are ionising (generate charged particles) • _ They destroy and damage human tissue (burning, damage of the cell genetic material,_ They destroy and damage human tissue (burning, damage of the cell genetic material, which can cause cancer)which can cause cancer) • RADIATIONRADIATION DOSEDOSE • Since it is known that radiation can be dangerous people have been searching forSince it is known that radiation can be dangerous people have been searching for criteria, which describe an amount of radiation that is still safe or has to be consideredcriteria, which describe an amount of radiation that is still safe or has to be considered dangerous. For this the general term dose is used. The following terms and units havedangerous. For this the general term dose is used. The following terms and units have been or are still used for this:been or are still used for this:
  9. 9. X-rays Safety:X-rays Safety: • __ ActivityActivity • This only describes the activity of radioactive material, being the number of atom changesThis only describes the activity of radioactive material, being the number of atom changes (emissions) per unit of time.(emissions) per unit of time. • The unit in which the activity is expressed is Becquerel per second or Bq/s. The old unit isThe unit in which the activity is expressed is Becquerel per second or Bq/s. The old unit is the Curie or Ci (1 Ci=3.7·1010 Bq/s).the Curie or Ci (1 Ci=3.7·1010 Bq/s). • __ ExposureExposure • Exposure is the quantity of released charge per kilogram of air.Exposure is the quantity of released charge per kilogram of air. • The unit in which exposure is expressed is Coulomb per kilogram air or C/kg.The unit in which exposure is expressed is Coulomb per kilogram air or C/kg. • The old unit is the Roentgen or R. (1 R=2.58·10-4 C/kg).The old unit is the Roentgen or R. (1 R=2.58·10-4 C/kg). • __ AbsorbedAbsorbed dosedose • The absorbed dose is the absorbed energy per kilogram of material. The unit in whichThe absorbed dose is the absorbed energy per kilogram of material. The unit in which absorbed dose is expressed is Gray or Gy (1 Gy =1 J/kg).The old unit is the Radiationabsorbed dose is expressed is Gray or Gy (1 Gy =1 J/kg).The old unit is the Radiation absorbed dose or Rad (1 Rad=0.01 Gy). absorbed dose or Rad (1 Rad=0.01 Gy).  • -Dose-Dose equivalentequivalent • The dose equivalent is the absorbed dose multiplied by a quality factor.This quality factor isThe dose equivalent is the absorbed dose multiplied by a quality factor.This quality factor is depending on the type of radiation and its relative damaging potential:depending on the type of radiation and its relative damaging potential: • The unit in which dose equivalent is expressed is the Sievert or Sv (1 Sv =1 Gy=1 J/kg).The unit in which dose equivalent is expressed is the Sievert or Sv (1 Sv =1 Gy=1 J/kg). • The old unit is the Röntgen Equivalent Men or REMThe old unit is the Röntgen Equivalent Men or REM • (1 REM=0.01 Sv).(1 REM=0.01 Sv).
  10. 10. X-rays Safety:X-rays Safety: • EFFECTSEFFECTS ONON THETHE HUMANHUMAN BODYBODY • The overall effects on the human body depending on the total dose received are of courseThe overall effects on the human body depending on the total dose received are of course very important. The following table gives an overview of the effects and chance of survivalvery important. The following table gives an overview of the effects and chance of survival after an exposure to a radiation source.after an exposure to a radiation source. • TotalTotal bodybody exposure Effectexposure Effect onon humanhuman body Chancesbody Chances ofof survivalsurvival • 100 Sv Damage to central nerve system No chance/Only few hours100 Sv Damage to central nerve system No chance/Only few hours • 10 Sv Damage to stomach, guts, bone marrow Little, <50%10 Sv Damage to stomach, guts, bone marrow Little, <50% • 1 Sv Change in blood composition Reasonable, >50%1 Sv Change in blood composition Reasonable, >50% • 0.1 Sv no physical damage Complete recovery after about 6 weeks0.1 Sv no physical damage Complete recovery after about 6 weeks
  11. 11. X-rays Legislation:X-rays Legislation: • LEGISLATIONLEGISLATION • Country OfficialCountry Official DocumentsDocuments ContainingContaining RegulationsRegulations • GermanyGermany Verordnung über den Schutz vor Schaden durch RöntgenstrahlenVerordnung über den Schutz vor Schaden durch Röntgenstrahlen • UKUK The Ionising Radiation Regulation, 1985, United KingdomThe Ionising Radiation Regulation, 1985, United Kingdom • USAUSA Radiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment, (NBSRadiation Safety for X-ray Diffraction and Fluorescence Analysis Equipment, (NBS hand book 1977)Department of Health Education and Welfare (DHEW), FDA 75 8003hand book 1977)Department of Health Education and Welfare (DHEW), FDA 75 8003 • CanadaCanada Radiation Emitting Devices Act, SOR/DORS/81-545,Radiation Emitting Devices Act, SOR/DORS/81-545, • Part XVIII: Cabinet of X-ray Equipment Consultative Document,Part XVIII: Cabinet of X-ray Equipment Consultative Document, • Part XIV: X-ray Diffraction EquipmentPart XIV: X-ray Diffraction Equipment • AustraliaAustralia Code of Practice for Protection against Ionising Radiation EmittedCode of Practice for Protection against Ionising Radiation Emitted • from X-ray Analysis Equipment, (1984)from X-ray Analysis Equipment, (1984) • The approach of Philips is to take care of the user (customer) and provide equipment thatThe approach of Philips is to take care of the user (customer) and provide equipment that is better than the lowest permissible dose limit. These dose limits are described in theis better than the lowest permissible dose limit. These dose limits are described in the legislation of the USA and the Netherlands and is currently 2.5 micro Sv/hour.legislation of the USA and the Netherlands and is currently 2.5 micro Sv/hour.
  12. 12. Theory of XRF:Theory of XRF: • Theory of XRF:Theory of XRF: • In XRF X-rays produced by a source irradiate a sample. In most case the source is an X-In XRF X-rays produced by a source irradiate a sample. In most case the source is an X- ray tube. The element present in the sample will emit the fluorescent x-ray radiation withray tube. The element present in the sample will emit the fluorescent x-ray radiation with discrete energies equivalent to color for optical light that are characteristics for thesediscrete energies equivalent to color for optical light that are characteristics for these elements. A different energy is equivalent to a different color. By measuring the energieselements. A different energy is equivalent to a different color. By measuring the energies determining the color of the radiation emitted by the sample it is possible to determinedetermining the color of the radiation emitted by the sample it is possible to determine which elements are present this step is called qualitative analysis. By measuring thewhich elements are present this step is called qualitative analysis. By measuring the intensities of the emitted energies (colors) it is possible to determine how much of eachintensities of the emitted energies (colors) it is possible to determine how much of each element is present in the sample. This step is called quantitative analysis.element is present in the sample. This step is called quantitative analysis. • Interaction of X-rays with matter:Interaction of X-rays with matter: • There are three main interactions of x-rays with matter:There are three main interactions of x-rays with matter: Fluorescence, ComptonFluorescence, Compton scatter and Rayleigh scatterscatter and Rayleigh scatter . If X-ray fall on a material a fraction will pass. If X-ray fall on a material a fraction will pass through the sample, a fraction is absorbed into the sample and produce fluorescentthrough the sample, a fraction is absorbed into the sample and produce fluorescent radiation, and a fraction is scattered back. Scattering can occur with loss of energy andradiation, and a fraction is scattered back. Scattering can occur with loss of energy and with out loss of energy. The first is calledwith out loss of energy. The first is called Compton scatterCompton scatter and the secondand the second RayleighRayleigh scatterscatter. The fluorescence and scatter depends upon the thickness (d) and density (ρ). The fluorescence and scatter depends upon the thickness (d) and density (ρ) and composition of the material and on the energy of the X-rays.and composition of the material and on the energy of the X-rays.
  13. 13. Theory of XRF:Theory of XRF: • Production of Characteristic fluorescent radiation:Production of Characteristic fluorescent radiation: • The classical model of an atom is a nucleus with positively charged protons and non-The classical model of an atom is a nucleus with positively charged protons and non- charged neutrons, surrounded by electrons grouped in shells or orbitals. The innermostcharged neutrons, surrounded by electrons grouped in shells or orbitals. The innermost shell is called the K-shell, followed by l-shells, M-shells etc travelling outwards. The L-shellshell is called the K-shell, followed by l-shells, M-shells etc travelling outwards. The L-shell has 3 sub shells called L1, L11 and LIII. The M shell has 5 sub shells. The K shell canhas 3 sub shells called L1, L11 and LIII. The M shell has 5 sub shells. The K shell can contain 2 electrons, the L-shell 8 and the M-shell 18. The energy an electron has dependscontain 2 electrons, the L-shell 8 and the M-shell 18. The energy an electron has depends on the shell it is in, and on the element to which it belongs. Irradiating an atom, particles likeon the shell it is in, and on the element to which it belongs. Irradiating an atom, particles like X-ray photons and electrons with sufficient energy can expel an electron from the atom.X-ray photons and electrons with sufficient energy can expel an electron from the atom. • This produces a hole in a shell, in the example a hole in the K-shell, putting the atom in anThis produces a hole in a shell, in the example a hole in the K-shell, putting the atom in an unstable situation with a higher energy. The atom wants to restore the originalunstable situation with a higher energy. The atom wants to restore the original configuration, and this is done by transferring an electron from an outer shell e.g. the l-shellconfiguration, and this is done by transferring an electron from an outer shell e.g. the l-shell to the hole in the K-shell. An L-shell electron has a higher energy than a K-shell electronto the hole in the K-shell. An L-shell electron has a higher energy than a K-shell electron and when the L-shell electron is transferred to the K-shell, the energy surplus is emitted asand when the L-shell electron is transferred to the K-shell, the energy surplus is emitted as X-rays. In a spectrum, this is seen as a line. The energy of the emitted X-rays depends onX-rays. In a spectrum, this is seen as a line. The energy of the emitted X-rays depends on the difference in energy of the shell with the initial hole and the energy of the electron thatthe difference in energy of the shell with the initial hole and the energy of the electron that fills the hole. Each atom has its specific energy levels, so the emitted radiation isfills the hole. Each atom has its specific energy levels, so the emitted radiation is characteristic for that atom. An atom emits more than just one energy (or line), becausecharacteristic for that atom. An atom emits more than just one energy (or line), because different holes can be produced and different electrons can fill up these holes. Thedifferent holes can be produced and different electrons can fill up these holes. The collection of emitted lines is characteristic for the element and is more or less a fingerprintcollection of emitted lines is characteristic for the element and is more or less a fingerprint of the element.of the element.
  14. 14. Theory of XRF:Theory of XRF: • To expel an electron from an atom, the x-rays must have a higher energy than the bindingTo expel an electron from an atom, the x-rays must have a higher energy than the binding energy of the electron. If an electron is expelled, the incoming radiation is absorbed and theenergy of the electron. If an electron is expelled, the incoming radiation is absorbed and the higher the absorption the higher the fluorescence. If on the other hand the energy is toohigher the absorption the higher the fluorescence. If on the other hand the energy is too high, many photons will pass the atom and only a few electrons will be removed. If thehigh, many photons will pass the atom and only a few electrons will be removed. If the energy is lower and comes closer to the binding energy of the K-shell electrons, more andenergy is lower and comes closer to the binding energy of the K-shell electrons, more and more radiation is absorbed. The highest yield is reached when the energy of the photon ismore radiation is absorbed. The highest yield is reached when the energy of the photon is just above the binding energy of the electron to be expelled. If the energy becomes lowerjust above the binding energy of the electron to be expelled. If the energy becomes lower than the binding energy, a jump or edge can be seen: the energy is too low to expelthan the binding energy, a jump or edge can be seen: the energy is too low to expel electrons from that shell, but is too high to expel electrons from the lower energetic shells.electrons from that shell, but is too high to expel electrons from the lower energetic shells. • Not all incoming photons produce fluorescent photons. The fluorescence yield is the ratio ofNot all incoming photons produce fluorescent photons. The fluorescence yield is the ratio of the emitted fluorescent photons and the number of incoming photons. the yield is low forthe emitted fluorescent photons and the number of incoming photons. the yield is low for the very light elements, explaining why it is so difficult to measure these elementsthe very light elements, explaining why it is so difficult to measure these elements..
  15. 15. Types of XRF’s:Types of XRF’s: Types of Spectrometer Systems:Types of Spectrometer Systems: There are two types of XRF Systems ,Energy Dispersive XRF & Wave lengthThere are two types of XRF Systems ,Energy Dispersive XRF & Wave length Dispersive XRFDispersive XRF EDXRF :EDXRF : • EDXRF Spectrometer have a detector that is able to measure the different energies ofEDXRF Spectrometer have a detector that is able to measure the different energies of the characteristics' radiation coming directly from the sample.The detector can separatethe characteristics' radiation coming directly from the sample.The detector can separate the radiation from the sample into the radiation from the elements in the sample.the radiation from the sample into the radiation from the elements in the sample. • WDXRD:WDXRD: • WDXRF Spectrometer use an analyzing crystal to disperse the different energies. AllWDXRF Spectrometer use an analyzing crystal to disperse the different energies. All radiation coming from the sample fall on the crystal. The crystal diffracts the differentradiation coming from the sample fall on the crystal. The crystal diffracts the different energies into different radiations ,similar to a prism that disperses colors into differentenergies into different radiations ,similar to a prism that disperses colors into different directions.directions. Is also possible to mount the detector on a goniometer and move it through an angular rangeIs also possible to mount the detector on a goniometer and move it through an angular range to measure the intensities of many different wave lengths. This system is called asto measure the intensities of many different wave lengths. This system is called as sequential systems because they measure the intensities of the different wavelengthssequential systems because they measure the intensities of the different wavelengths one After another. Simultaneous spectrometers are equipped with a set of fixed detectionone After another. Simultaneous spectrometers are equipped with a set of fixed detection system. Each detection system has its crystal and detector ,and each system measuressystem. Each detection system has its crystal and detector ,and each system measures the radiation of a specific element .the intensities are measured all at the samethe radiation of a specific element .the intensities are measured all at the same time,explaning why they are termed as simultaneous systems. combined systems havingtime,explaning why they are termed as simultaneous systems. combined systems having an moving detector and fixed detectors are also available.an moving detector and fixed detectors are also available.
  16. 16. Instrumentation:Instrumentation: • As XRF Present in BCL CHK is WDXRF ,therefore we will focus on WDXRF:As XRF Present in BCL CHK is WDXRF ,therefore we will focus on WDXRF: • Cubix 2300 XRF :Cubix 2300 XRF : • The spectrometer comprises the following major assemblies.The spectrometer comprises the following major assemblies. • Analyzer Containing:Analyzer Containing: • Measuring ChamberMeasuring Chamber • Element Channels & detectorsElement Channels & detectors • Sample Transport AssembleySample Transport Assembley • Vacumn PumpVacumn Pump • TT X-Ray Tube:TT X-Ray Tube: • Controller Containing:Controller Containing: • HT SupplyHT Supply • Internal Water Cooling SystemInternal Water Cooling System • CPU BoardCPU Board • Controller BoardController Board • Counting ElectronicsCounting Electronics
  17. 17. Instrumentation :Instrumentation : • Measuring Chamber :Measuring Chamber : • Measuring chamber is located in the analyzer.It consists of the measuring chamber itselfMeasuring chamber is located in the analyzer.It consists of the measuring chamber itself and 14 fixed measuring channels ,or optionally with a maximum of 11 fixed channels.and 14 fixed measuring channels ,or optionally with a maximum of 11 fixed channels.   • Element Channel :Element Channel : • A fixed element channel comprises the following ,A fixed element channel comprises the following , • Entrance SlitEntrance Slit • DiaphragmDiaphragm • Curved Crystal AssembleyCurved Crystal Assembley • Exit slitExit slit • DetectorDetector • Scaler CircuitScaler Circuit • Connecting CablesConnecting Cables • Each channel has a high tension supply for the detector and when a gas flow detector isEach channel has a high tension supply for the detector and when a gas flow detector is used ,a controlled gas supply.used ,a controlled gas supply.
  18. 18. Instrumentation :Instrumentation : • Detector & Multi Channel Analyzer :Detector & Multi Channel Analyzer : • EDXRF mainly use solid state detector ,while WDXRF use gas filled detectors andEDXRF mainly use solid state detector ,while WDXRF use gas filled detectors and scintillation detectors.EDXRF detector is a wide range detector and measures allscintillation detectors.EDXRF detector is a wide range detector and measures all elements from Na up to U.Gas filled detectors measures elements from Be upto Cu andelements from Na up to U.Gas filled detectors measures elements from Be upto Cu and scintilllation detector from Cu upto U.All these detectors' produce an electrical pulsescintilllation detector from Cu upto U.All these detectors' produce an electrical pulse when an X-Ray photon enters the detector ,and height of this pulse is proportional to thewhen an X-Ray photon enters the detector ,and height of this pulse is proportional to the energy of the incoming photon. The pulses are amplified and than counted by Multienergy of the incoming photon. The pulses are amplified and than counted by Multi Channel analyzer.Channel analyzer. • There are 03 important parameters of detection system:There are 03 important parameters of detection system: • Resolution :Resolution : • Is the ability of the detector to distinguish between different energy levels. A highIs the ability of the detector to distinguish between different energy levels. A high resolution means the detector can distinguish between different energies level.resolution means the detector can distinguish between different energies level. • Sensitivity :Sensitivity : • Indicates how efficiently incoming photons are counted. Sensitivity is high if the ratio ofIndicates how efficiently incoming photons are counted. Sensitivity is high if the ratio of number of pulses against the number of incoming photons is high.number of pulses against the number of incoming photons is high. • Dispersion :Dispersion : • Indicates the ability of the detector to separate X-rays with different energies. highIndicates the ability of the detector to separate X-rays with different energies. high dispersion means different energies are separated well.dispersion means different energies are separated well. • As in our XRF System there is gas filled detector system, therefore well focus on them :As in our XRF System there is gas filled detector system, therefore well focus on them :
  19. 19. Instrumentation :Instrumentation : • Gas Filled Detector System:Gas Filled Detector System: • The sealed gas detector is a hollow metal cylinder with an anode wire running in the axialThe sealed gas detector is a hollow metal cylinder with an anode wire running in the axial centre of the cylinder. The cylinder is sealed of and has a gas mixture inside, containingcentre of the cylinder. The cylinder is sealed of and has a gas mixture inside, containing the inert counting gas (Ne,Ar,Kr ,Xe and occasionally He) and the quench gas Methane.the inert counting gas (Ne,Ar,Kr ,Xe and occasionally He) and the quench gas Methane. On one side of the cylinder a Be window is mounted through which the X-ray photons canOn one side of the cylinder a Be window is mounted through which the X-ray photons can enter. When an X-ray photon enters the detector and collides with an inert gas atom anenter. When an X-ray photon enters the detector and collides with an inert gas atom an outer electron may be knocked out forming an ion-electron pair. The number of ion-outer electron may be knocked out forming an ion-electron pair. The number of ion- electron pairs is depending on the energy of the X-ray photon. The electrons from theelectron pairs is depending on the energy of the X-ray photon. The electrons from the ion-electron pair are then accelerated towards the anode wire by its high potential. In itsion-electron pair are then accelerated towards the anode wire by its high potential. In its path such an accelerating electron can again knock out an electron from an atom,path such an accelerating electron can again knock out an electron from an atom, forming another ion-electron pair etc.This will cause an avalanche of electrons, the so-forming another ion-electron pair etc.This will cause an avalanche of electrons, the so- called gas amplification. When this avalanche of electrons reaches the anode wire, acalled gas amplification. When this avalanche of electrons reaches the anode wire, a small voltage pulse is produced. This voltage pulse is proportional to the energy of the X-small voltage pulse is produced. This voltage pulse is proportional to the energy of the X- ray photon and the applied HT.If negative ions are produced also positive ions areray photon and the applied HT.If negative ions are produced also positive ions are produced. These positive ions are attracted to the detector case at earth potential andproduced. These positive ions are attracted to the detector case at earth potential and they will also cause an avalanche. To prevent this, the inert gas is mixed with a quenchthey will also cause an avalanche. To prevent this, the inert gas is mixed with a quench gas, such as Methane. The quench gas has the effect of neutralizing the positive ionsgas, such as Methane. The quench gas has the effect of neutralizing the positive ions without any other reactions.without any other reactions.
  20. 20. Instrumentation :Instrumentation : • Gas Flow Proportional Detector:Gas Flow Proportional Detector: • It is used for X-Rays having energies between 0.28 KeV & 3 KeV.It is operated with aIt is used for X-Rays having energies between 0.28 KeV & 3 KeV.It is operated with a continuous flow of gas .P10 Gas is used 90 % Argon & 10 % Methane .The gas flowcontinuous flow of gas .P10 Gas is used 90 % Argon & 10 % Methane .The gas flow must be between 0.5 & 1 LITRE / HOUR.must be between 0.5 & 1 LITRE / HOUR. • The recommended use is for lighter elements from C to Mg.It is also possible to use thisThe recommended use is for lighter elements from C to Mg.It is also possible to use this detector for Al to Cr.detector for Al to Cr. • Neon Sealed Proportional Detector :Neon Sealed Proportional Detector : • It is used for X-Rays having energies between 1.5 KeV & 3 KeV.The detector is filled &It is used for X-Rays having energies between 1.5 KeV & 3 KeV.The detector is filled & sealed with Neon gas mixture.sealed with Neon gas mixture. • The Neon sealed detector fitted with 25 Um window can be used to analyze elementsThe Neon sealed detector fitted with 25 Um window can be used to analyze elements from Al upto P.A detector with a 50 um window is used to analyze elements from S uptofrom Al upto P.A detector with a 50 um window is used to analyze elements from S upto Cl.Cl. • Krypton Sealed Proportional Detector :Krypton Sealed Proportional Detector : • It is used for X-Rays having energies between 3 KeV & 8 KeV.The detector is filled &It is used for X-Rays having energies between 3 KeV & 8 KeV.The detector is filled & sealed with Krypton gas mixture.sealed with Krypton gas mixture. • The Krypton sealed detector can be used to analyze elements from K upto Cu (K Line).AThe Krypton sealed detector can be used to analyze elements from K upto Cu (K Line).A & for the L-Line analysis of elements from Te to Ta.& for the L-Line analysis of elements from Te to Ta.
  21. 21. Instrumentation :Instrumentation : • Xenon Sealed Proportional Detector :Xenon Sealed Proportional Detector : • It is used for X-Rays having energies between 6 KeV & 16 KeV.The detector is filled &It is used for X-Rays having energies between 6 KeV & 16 KeV.The detector is filled & sealed with Xenon gas mixture.sealed with Xenon gas mixture. • The Xenon sealed detector can be used to analyze elements from Zn upto Y (K Line). &The Xenon sealed detector can be used to analyze elements from Zn upto Y (K Line). & for the L-Line analysis of elements from Ta to U.for the L-Line analysis of elements from Ta to U. • COMPARISON OF DIFFERENT DECTECTORSCOMPARISON OF DIFFERENT DECTECTORS • The resolution of gas filled and scintillation detectors are very poor, and they are notThe resolution of gas filled and scintillation detectors are very poor, and they are not suited for energy dispersive spectrometers. They can however be used in wavelengthsuited for energy dispersive spectrometers. They can however be used in wavelength dispersive spectrometers, because in these instruments the resolution is achieved by thedispersive spectrometers, because in these instruments the resolution is achieved by the diffraction crystal. The sensitivity depends on the type of detector and on the energy ofdiffraction crystal. The sensitivity depends on the type of detector and on the energy of the incoming X- rays. Gas –filled detectors have a high sensitivity for low energy and athe incoming X- rays. Gas –filled detectors have a high sensitivity for low energy and a low sensitivity for high energies and are so best suited to detect low energies. Thelow sensitivity for high energies and are so best suited to detect low energies. The opposite applies for scintillation detectors ,which are better suited for high energies thanopposite applies for scintillation detectors ,which are better suited for high energies than low energies .Solid state detectors in general have a very low sensitivity for low energieslow energies .Solid state detectors in general have a very low sensitivity for low energies and high resolution for the higher energies.EDXRF Spectrometer commonly use solidand high resolution for the higher energies.EDXRF Spectrometer commonly use solid state detector ,while WDXRF spectrometers use a combination of gas filled andstate detector ,while WDXRF spectrometers use a combination of gas filled and scintillation detector.scintillation detector.
  22. 22. Instrumentation :Instrumentation : • Lif 220 Crystal 2d = 0.2848 nm: used for elemental range V-U, highLif 220 Crystal 2d = 0.2848 nm: used for elemental range V-U, high resolution analysisresolution analysis • LiF200 Crystal :2d=0.4027 nm : used for elemental K-U ,routine analysis.LiF200 Crystal :2d=0.4027 nm : used for elemental K-U ,routine analysis. • Insb (111) Crystal 2d= 0.7477 : this is only used for silicon and gives aInsb (111) Crystal 2d= 0.7477 : this is only used for silicon and gives a higher sensitivity than PE with also an improved resolutionhigher sensitivity than PE with also an improved resolution • PE (002) Crystal 2d=0.8742 nm : Elemental range Al-Cl. Routine analysisPE (002) Crystal 2d=0.8742 nm : Elemental range Al-Cl. Routine analysis • PX1 Synthetic Multilayer 2d = 5 nm: Analysis range O-MgPX1 Synthetic Multilayer 2d = 5 nm: Analysis range O-Mg • PX4 Synthetic Multilayer : 2d = 12nm used for analysis of carbon.PX4 Synthetic Multilayer : 2d = 12nm used for analysis of carbon. • Counting & Control Electronics :Counting & Control Electronics : • The Dual scaler board is used to count the detected pulses. This data is passed to theThe Dual scaler board is used to count the detected pulses. This data is passed to the SuperQ analytical software as raw count rate. The Dual scaler board also sets theSuperQ analytical software as raw count rate. The Dual scaler board also sets the detector high voltage leveldetector high voltage level ..
  23. 23. Instrumentation :Instrumentation : • Detector High Voltage Supplies :Detector High Voltage Supplies : • A high voltage supply is required for each type of detector.A high voltage supply is required for each type of detector. • A gas -flow or sealed detector is supplied with between 1000 to 3000 volts.A gas -flow or sealed detector is supplied with between 1000 to 3000 volts. • The detector high voltage supply is controlled by the Dual Scaler Board.The detector high voltage supply is controlled by the Dual Scaler Board. • Chamber Atmosphere:Chamber Atmosphere: • The inside of the chamber is kept under vacuum ,the vacuum ensures the highestThe inside of the chamber is kept under vacuum ,the vacuum ensures the highest possible intensity for light elements. Whole of the sample transport system and thepossible intensity for light elements. Whole of the sample transport system and the measuring chamber is under vacuum.measuring chamber is under vacuum. • HV Generator :HV Generator : • The high voltage supply is basically a 200 Watt high voltage converter withThe high voltage supply is basically a 200 Watt high voltage converter with negative polarity.negative polarity. • Routine X Rays Check :Routine X Rays Check : • Cleaning the Loading OpeningCleaning the Loading Opening • Cleaning the air dust FilterCleaning the air dust Filter • Vacumn Pump Oil level CheckVacumn Pump Oil level Check • Vacumn Pump Oil Conditions CheckVacumn Pump Oil Conditions Check • Fore line Trap CheckFore line Trap Check
  24. 24. Instrumentation :Instrumentation : • X-Rays Tubes:X-Rays Tubes: • The basic design of X-Ray Tube contains a filament (wire) and an anode (target) placedThe basic design of X-Ray Tube contains a filament (wire) and an anode (target) placed in an vacuum housing. An electrical current heats up the filament and electrons arein an vacuum housing. An electrical current heats up the filament and electrons are emitted, which hit the atoms in the anode which will expel the electrons from thesesemitted, which hit the atoms in the anode which will expel the electrons from theses atoms, causing emission of characteristics radiation. The energy of this radiation isatoms, causing emission of characteristics radiation. The energy of this radiation is determined by the elements in the anode. The X-Rays emitted escape through Bedetermined by the elements in the anode. The X-Rays emitted escape through Be Window .There are two types of X-Ray Tube Side-Window tubes & Target transmissionWindow .There are two types of X-Ray Tube Side-Window tubes & Target transmission Tubes .A high voltage (20….100Kv ) is applied across the filamentTubes .A high voltage (20….100Kv ) is applied across the filament t and the anode ,andt and the anode ,and this high voltage accelerates the electrons towards the anode.this high voltage accelerates the electrons towards the anode. • The conversion of electrons into X-rays is a very inefficient process. About 1% of theThe conversion of electrons into X-rays is a very inefficient process. About 1% of the applied energy is converted to X-rays. The remainder of the energy is converted to heatapplied energy is converted to X-rays. The remainder of the energy is converted to heat within the anode. Therefore, the backside of the anode is cooled with a high-speedwithin the anode. Therefore, the backside of the anode is cooled with a high-speed water jet of about 4 litres/ minute. A number of electrons are scattered from the anodewater jet of about 4 litres/ minute. A number of electrons are scattered from the anode and strike other parts of the tube such as the window.and strike other parts of the tube such as the window. • Therefore, the temperature of the window can rise to hundreds of degrees C.Therefore, the temperature of the window can rise to hundreds of degrees C. • The window is made of Beryllium (atomic weight 4) in order to minimize the absorptionThe window is made of Beryllium (atomic weight 4) in order to minimize the absorption of X-rays. The thickness of the window depends on the ability to conduct heat from theof X-rays. The thickness of the window depends on the ability to conduct heat from the window to the tube body to avoid fracture of the windowwindow to the tube body to avoid fracture of the window •
  25. 25. InstrumentationInstrumentation
  26. 26. Channels SpecificationsChannels Specifications Element Crystal Type Angle Si Insb111 Flow 144.75 Al PE002 Flow 144.86 Fe LiF200 Sealed Kr 57.52 Ca LiF200 Sealed Kr 113.08 Mg PX1 Flow 22.56 K LiF200 Sealed Kr 136.69 Na PX1 Flow 27.48 S Ge111 Sealed Ne 110.68 Cl PE002 Sealed Ne 65.49
  27. 27. Equipment Details:Equipment Details: Max Min Gas Flow 3.0 l / hrs,1300 hpa 0.5 l/hrs ,600 hpa X-Ray Tube 50 kv,4 ma Cr 200 W Vacumn 100 pa 0 pa Temp 36.40 C 35.90 C Compressed Air 6 Bar 4 Bar
  28. 28. Standardization of XRF:Standardization of XRF: • STANDARDIZATION OF XRF ANALYSISSTANDARDIZATION OF XRF ANALYSIS • Several standards are available to monitor quality assurance and certification of XRFSeveral standards are available to monitor quality assurance and certification of XRF equipment performance and accuracy. A brief description of select materials is givenequipment performance and accuracy. A brief description of select materials is given below:below: • Standard Reference MaterialsStandard Reference Materials • A number of Certified Reference Materials (CRMs) and Reference Materials (RMs)A number of Certified Reference Materials (CRMs) and Reference Materials (RMs) are available from many sources. The definitions for CRM and RM as listed in theare available from many sources. The definitions for CRM and RM as listed in the International Organization for Standardization's ISO Guide 30:1992, “Terms andInternational Organization for Standardization's ISO Guide 30:1992, “Terms and Definitions Used in Connection with Reference Materials,” are listed below.Definitions Used in Connection with Reference Materials,” are listed below. • Certified Reference Material (CRM).Certified Reference Material (CRM). Reference material, accompanied by aReference material, accompanied by a certificate, one or more of whose property values are certified by a procedure whichcertificate, one or more of whose property values are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the propertyestablishes its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by anvalues are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence. CRMs are certified by a recognizeduncertainty at a stated level of confidence. CRMs are certified by a recognized certifying organization using approved certification procedures as instructed incertifying organization using approved certification procedures as instructed in
  29. 29. Standardization of XRF:Standardization of XRF: • ISO Guide 35:1989, “Certification of Reference Materials – General and StatisticalISO Guide 35:1989, “Certification of Reference Materials – General and Statistical Principles.” The organization is usually a function of a federal government orPrinciples.” The organization is usually a function of a federal government or recognized by a federal government .A CRM is the highest level to which anrecognized by a federal government .A CRM is the highest level to which an analytical reference material can be elevated.analytical reference material can be elevated. • Reference Material (RM):Reference Material (RM): A material substance one or more of whose propertyA material substance one or more of whose property values are sufficiently homogeneous and well established to be used for thevalues are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method, or assigningcalibration of an apparatus, the assessment of a measurement method, or assigning values to materials. The RMs usually have been through inter laboratory testing usingvalues to materials. The RMs usually have been through inter laboratory testing using many analysts and supplied with a certificate of analysis but do not strictly follow themany analysts and supplied with a certificate of analysis but do not strictly follow the procedures of certification as indicated in ISO Guide 35:1989.procedures of certification as indicated in ISO Guide 35:1989. • It is interesting to note that no cement raw mix standards exist – and for good reason.It is interesting to note that no cement raw mix standards exist – and for good reason. Mineralogy of the kiln feed is variable at different cement plants; some use clay andMineralogy of the kiln feed is variable at different cement plants; some use clay and limestone and others contain quartz, fly ash, bottom ash, and many other materials.limestone and others contain quartz, fly ash, bottom ash, and many other materials. Significantly different results may result depending on the ingredients when usingSignificantly different results may result depending on the ingredients when using pressed powders in analyses. However, if the fusion technique is used, cementpressed powders in analyses. However, if the fusion technique is used, cement calibrations can be used effectively to analyze raw feed andcalibrations can be used effectively to analyze raw feed and
  30. 30. Standardization of XRF :Standardization of XRF : • clinker as well. Careful attention to sulfur, alkalis , and chloride is still required. Cementclinker as well. Careful attention to sulfur, alkalis , and chloride is still required. Cement standards, available from NIST, vary in composition so they can be used in calibrationstandards, available from NIST, vary in composition so they can be used in calibration or qualification under ASTM C 114.3. Supplies usually last 15 years or more asor qualification under ASTM C 114.3. Supplies usually last 15 years or more as thousands of samples are packaged and randomly tested for homogeneity andthousands of samples are packaged and randomly tested for homogeneity and composition to produce a Certificate of Analysis (COA).composition to produce a Certificate of Analysis (COA). Other reference materialOther reference material suppliers have one or two standards, which will add to the number of samples used forsuppliers have one or two standards, which will add to the number of samples used for calibration, or can supplement the qualification of the test methods. Because thecalibration, or can supplement the qualification of the test methods. Because the Cement and Concrete Reference Laboratory (CCRL) samples are analyzed by 100Cement and Concrete Reference Laboratory (CCRL) samples are analyzed by 100 laboratories or more and statistically evaluated, it is not uncommon for these samples tolaboratories or more and statistically evaluated, it is not uncommon for these samples to be used as standards in calibration work. Caution is warranted in this practice becausebe used as standards in calibration work. Caution is warranted in this practice because the results are averages of many labs’ results, not “certificate values.” Nettles (1998)the results are averages of many labs’ results, not “certificate values.” Nettles (1998) proposed using pure compounds formulated to mimic the composition of the 1800proposed using pure compounds formulated to mimic the composition of the 1800 series cements using the fusion technique. Other sources of reference materials can beseries cements using the fusion technique. Other sources of reference materials can be found in Appendix E.found in Appendix E. • Drift standards.Drift standards. Drift standards correct for any instrumental changes such as x-rayDrift standards correct for any instrumental changes such as x-ray tube agingtube aging,, detector sensitivity, etc. Such drift standards should be stable materials freedetector sensitivity, etc. Such drift standards should be stable materials free from changes due to exposure to x-rays and aging. Typically, driftfrom changes due to exposure to x-rays and aging. Typically, drift
  31. 31. Standardization of XRF:Standardization of XRF: standards are fused beads for cement. Currently available are glass standards made by A.S.O.standards are fused beads for cement. Currently available are glass standards made by A.S.O. Design specifically formulated for Portland cement manufacture concentration ranges. BreitlanderDesign specifically formulated for Portland cement manufacture concentration ranges. Breitlander also supplies glass drift standards. In any case, the drift correction must be used if chemicalalso supplies glass drift standards. In any case, the drift correction must be used if chemical results indicate substantial evidence that the method is not providing results in accordance withresults indicate substantial evidence that the method is not providing results in accordance with ASTM permissible limits.ASTM permissible limits. If the required accuracy on a major element is 0.1% relative and theIf the required accuracy on a major element is 0.1% relative and the measured count rate fluctuates between -0.4% and +0.4% during a period of one week, then onemeasured count rate fluctuates between -0.4% and +0.4% during a period of one week, then one measurement a day is likely to be sufficient to obtain the required accuracy.measurement a day is likely to be sufficient to obtain the required accuracy. • The PHDThe PHD is the energy distribution of the pulses produced by a detector. The detector countis the energy distribution of the pulses produced by a detector. The detector count rates are displayed as a function of energy using the Check PHD function. Only those signalsrates are displayed as a function of energy using the Check PHD function. Only those signals which originate from the element of interest need to be processed from all the signals which arewhich originate from the element of interest need to be processed from all the signals which are detected. To define the appropriate signals, you must measure a pulse height distribution and setdetected. To define the appropriate signals, you must measure a pulse height distribution and set thethe upper and lower levelsupper and lower levels between which the signal will be integrated for further processing.between which the signal will be integrated for further processing. The remaining signals are disregarded and only used for dead time correction.The remaining signals are disregarded and only used for dead time correction. • Different settings are recommended for the upper and lower levels depending on which signalDifferent settings are recommended for the upper and lower levels depending on which signal you want to measure.you want to measure. • Pulse shiftPulse shift is an effect that is caused by incoming X-rays. At very high count rates the analyteis an effect that is caused by incoming X-rays. At very high count rates the analyte signal partially shifts outside the selected PHD window. The electronics in the spectrometersignal partially shifts outside the selected PHD window. The electronics in the spectrometer correct for this effect using pulse shift correction which is designed to maintain stability. Thiscorrect for this effect using pulse shift correction which is designed to maintain stability. This ensures linearity between the measured or reported count rate and the actually absorbed countensures linearity between the measured or reported count rate and the actually absorbed count rate. The magnitude of pulse shift depends on both the energy and the count rate of therate. The magnitude of pulse shift depends on both the energy and the count rate of the absorbed flux (including the part which is not measured) in the detector.absorbed flux (including the part which is not measured) in the detector.
  32. 32. Theory of XRDTheory of XRD Diffraction Crystals & Collimators :Diffraction Crystals & Collimators : • A crystal can be seen as a stack of thin layers all having the same thickness. If aA crystal can be seen as a stack of thin layers all having the same thickness. If a parallel beam of X-Rays falls on the crystal ,the first layer reflects a fraction of the X-parallel beam of X-Rays falls on the crystal ,the first layer reflects a fraction of the X- Ray. The remaining radiation penetrates the crystal and is reflected by theRay. The remaining radiation penetrates the crystal and is reflected by the subsequent layers. If the difference in path length between reflections from layers issubsequent layers. If the difference in path length between reflections from layers is multiple of half the wave length of the radiation, the two reflected beams vanish. If themultiple of half the wave length of the radiation, the two reflected beams vanish. If the difference is exactly an integer times the wavelength ,the two reflected beams redifference is exactly an integer times the wavelength ,the two reflected beams re inforce.The difference in path length is an integer times ,the wavelength if theinforce.The difference in path length is an integer times ,the wavelength if the following relation ,called Braggs law ,holds. Nλ= 2d sin (Ф)following relation ,called Braggs law ,holds. Nλ= 2d sin (Ф) • At an angle ,all reflected radiation with a wavelength and obeying braggs law are inAt an angle ,all reflected radiation with a wavelength and obeying braggs law are in phase and add up. All other wavelengths at the same angle will vanish,phase and add up. All other wavelengths at the same angle will vanish, • A detector placed at angle can therefore measure the intensity of the correspondingA detector placed at angle can therefore measure the intensity of the corresponding wavelength. Reflected wavelengths obeying braggs law for n=1 are called first orderwavelength. Reflected wavelengths obeying braggs law for n=1 are called first order reflection ,for n=2 second order .At any specific angle ,only radiation with areflection ,for n=2 second order .At any specific angle ,only radiation with a wavelength obeying braggs law is reflected. Radiation with slightly differentwavelength obeying braggs law is reflected. Radiation with slightly different wavelength will be reflected at slightly different angles ,but will still reach the detectorwavelength will be reflected at slightly different angles ,but will still reach the detector and will interfere with the energy to be measured. A collimator ,which is set of paralleland will interfere with the energy to be measured. A collimator ,which is set of parallel plates ,is used to obtain a parallel X-Ray beam that falls exactly at the required angleplates ,is used to obtain a parallel X-Ray beam that falls exactly at the required angle on the crystal. the primary collimator is placed between the sample and crystal ,andon the crystal. the primary collimator is placed between the sample and crystal ,and on secondary collimator can be placed between the crystal and the detector.on secondary collimator can be placed between the crystal and the detector.
  33. 33. XRD:XRD: Goniometer ,X Ray Tube (Ø1)-5 to 85 Ø ,Detector (-5 to 85 Ø ) 2Ø 0---167ØGoniometer ,X Ray Tube (Ø1)-5 to 85 Ø ,Detector (-5 to 85 Ø ) 2Ø 0---167Ø X-Ray Tube (Ø----Ø Geometry) (Copper ,2200 W)X-Ray Tube (Ø----Ø Geometry) (Copper ,2200 W) • ß Filter (Ni )ß Filter (Ni ) • Diversion Slit (1Ø)Diversion Slit (1Ø) • Solar Slit (0.04 Radians)Solar Slit (0.04 Radians) • Width Mask (10mm)Width Mask (10mm) • SampleSample • Fixed Anti scatter Slit (2Ø)Fixed Anti scatter Slit (2Ø) • Programmable Receiving Slit (0.1mm-3mm),Opening Increment 0.01 mmProgrammable Receiving Slit (0.1mm-3mm),Opening Increment 0.01 mm • Solar Slit (0.04 Radians)Solar Slit (0.04 Radians) • X-Celerator Detector (Combination of 100 Solid State detectors ,thereforeX-Celerator Detector (Combination of 100 Solid State detectors ,therefore processing time is 100 times fast)processing time is 100 times fast)
  34. 34. Equipment DetailsEquipment Details Max Min Water Flow 6.0 l / min 3.5 l/min Water Input Pressure 50 PSI 115 PSI Water Temperature + 35 c + 20 C Compressed Air 6 Bar 4 Bar
  35. 35. Why use X-raysWhy use X-rays • There are various reasons why a choice is made for X-ray analysis:There are various reasons why a choice is made for X-ray analysis: • __ UniquenessUniqueness ofof thethe methodmethod • X-ray diffraction is very often the only technique available to analyse materialX-ray diffraction is very often the only technique available to analyse material properties, certainly when these depend on the crystalline state.properties, certainly when these depend on the crystalline state. • __ SpeedSpeed ofof analysisanalysis • Each measurement (analysis) can take only a few minutes, which allows a highEach measurement (analysis) can take only a few minutes, which allows a high through-put of samples.through-put of samples. • XRF only takesXRF only takes one minuteone minute for analysis of 09 elementsfor analysis of 09 elements • While XRD TakesWhile XRD Takes five & Half minutesfive & Half minutes for analysis offor analysis of C3S,C2S,C3A,C4AF,MaO.fCaO,KC3S,C2S,C3A,C4AF,MaO.fCaO,K22SOSO44 CLASSICALCLASSICAL Method takesMethod takes 06 Hrs06 Hrs for Cement /for Cement / Clinker ,while at leastClinker ,while at least 12 Hours12 Hours for Raw Materials. (Excluding Alkalis)for Raw Materials. (Excluding Alkalis) • Non-destructiveNon-destructive analysisanalysis • Samples remain unchanged during and after measurement, which means that otherSamples remain unchanged during and after measurement, which means that other analysis techniques may be used on the same samples, or samples may beanalysis techniques may be used on the same samples, or samples may be preserved when needed.preserved when needed. • __ LargeLarge rangerange ofof materialsmaterials • All element from atomic weight 4 (Beryllium) with the exception of Nitrogen can beAll element from atomic weight 4 (Beryllium) with the exception of Nitrogen can be analysed with X-ray fluorescence.analysed with X-ray fluorescence. • All crystalline and semi-crystalline structures can be tested with X-ray diffraction,All crystalline and semi-crystalline structures can be tested with X-ray diffraction, however no liquids can be analysed.however no liquids can be analysed.
  36. 36. Why use X-raysWhy use X-rays • __ AccurateAccurate analysisanalysis • Relative accuracies of 0.1% to 0.3% are attainable.Relative accuracies of 0.1% to 0.3% are attainable. • __ SensitivitySensitivity • With X-ray fluorescence elements can be detected in concentrations from 0.1 PPM upWith X-ray fluorescence elements can be detected in concentrations from 0.1 PPM up to 100 % (PPM = parts per million).to 100 % (PPM = parts per million). • With X-ray diffraction, crystalline structures can be analysed with a concentration ofWith X-ray diffraction, crystalline structures can be analysed with a concentration of typically 0.1% up to 100%. In exceptional situations concentrations below 0.1% aretypically 0.1% up to 100%. In exceptional situations concentrations below 0.1% are attainable.attainable. • __ RangeRange ofof samplesample typestypes • Samples may be in many forms and shapes, with dimensions ranging from tens ofSamples may be in many forms and shapes, with dimensions ranging from tens of microns to meters.microns to meters. • __ EaseEase ofof useuse • Routine analyses do not require a high level of operator skills.Routine analyses do not require a high level of operator skills. • __ AutomatedAutomated operationoperation • The whole process of sample taking, sample preparation and the final measurementThe whole process of sample taking, sample preparation and the final measurement cancan • sometimes be highly automated ensuring a high throughput of samples.sometimes be highly automated ensuring a high throughput of samples.
  37. 37. Uses of XRD & XRF :Uses of XRD & XRF : 1. Calculation of actual C3S,C2S,Ortho C3A,Cubic C3A ,C4AF,Mgo1. Calculation of actual C3S,C2S,Ortho C3A,Cubic C3A ,C4AF,Mgo (Periclase) , Free Lime & K2S04 in Clinker.(Periclase) , Free Lime & K2S04 in Clinker. 2. Quartz in limestone.2. Quartz in limestone. One major problem in cement manufacturing is achievingOne major problem in cement manufacturing is achieving proper grindingproper grinding and fineness of the material that is to enter the kiln. The presence of coarse quartz inand fineness of the material that is to enter the kiln. The presence of coarse quartz in limestonelimestone can have an impact on both the parameters. Assessment of coarse quartz in rawcan have an impact on both the parameters. Assessment of coarse quartz in raw feed can effectively be made by XRD in conjunction with acid treatment of the samplefeed can effectively be made by XRD in conjunction with acid treatment of the sample and particle separation. The raw feed is treated with dilute hydrochloric acid until alland particle separation. The raw feed is treated with dilute hydrochloric acid until all carbonates have been decomposed. The residue is then filtered, dried, and analyzedcarbonates have been decomposed. The residue is then filtered, dried, and analyzed by XRD. The XRD pattern showing quartz peaks gives an estimation of insolubleby XRD. The XRD pattern showing quartz peaks gives an estimation of insoluble quartz in the feed. Figure shows the XRD pattern of a raw feed prepared by thisquartz in the feed. Figure shows the XRD pattern of a raw feed prepared by this procedure. Reference pattern lines superimposed on the sample’s pattern indicateprocedure. Reference pattern lines superimposed on the sample’s pattern indicate the position and intensity for major quartz peaks.the position and intensity for major quartz peaks.
  38. 38. Uses of XRD & XRF:Uses of XRD & XRF: (XRD Pattern of KF treated with HCL Filtered & dried)(XRD Pattern of KF treated with HCL Filtered & dried)
  39. 39. Uses of XRD & XRF:Uses of XRD & XRF: • Additionally, if the insoluble residue is sieved through a No. 325 sieve, and the XRDAdditionally, if the insoluble residue is sieved through a No. 325 sieve, and the XRD pattern of the portion retained on the sieve is obtained, abundance of quartz coarserpattern of the portion retained on the sieve is obtained, abundance of quartz coarser than 45 µm can be estimated from this fraction. Figure shows the XRD pattern of athan 45 µm can be estimated from this fraction. Figure shows the XRD pattern of a coarse fraction obtained after acid treatment of a cement raw feed. It is apparent thatcoarse fraction obtained after acid treatment of a cement raw feed. It is apparent that this kiln feed sample has a relatively high amount of coarse quartz .Because quartz isthis kiln feed sample has a relatively high amount of coarse quartz .Because quartz is harder to grind than other materials in the raw feed and is harder to burn, it is likelyharder to grind than other materials in the raw feed and is harder to burn, it is likely that cement produced with this kiln feed will contain belite clusters formed duringthat cement produced with this kiln feed will contain belite clusters formed during clinkering process. Raw feed containing coarse quartz will require more grindingclinkering process. Raw feed containing coarse quartz will require more grinding energy to produce a quality clinker.energy to produce a quality clinker.
  40. 40. XRD pattern of kiln feed sample treated with diluted HCl, filtered,XRD pattern of kiln feed sample treated with diluted HCl, filtered, dried, and sieved through a 45 µm-size sieve. Reference lines fordried, and sieved through a 45 µm-size sieve. Reference lines for quartz are shown.quartz are shown.
  41. 41. Uses of XRD & XRF:Uses of XRD & XRF: • Gypsum RockGypsum Rock In the sense that gypsum is added to clinker during inter grinding in the finish mill, it is considered aIn the sense that gypsum is added to clinker during inter grinding in the finish mill, it is considered a raw material in cement manufacturing. Its purpose is to control setting when the cement startsraw material in cement manufacturing. Its purpose is to control setting when the cement starts to hydrate. Gypsum is generally secured from naturally occuring deposits in the earth In naturalto hydrate. Gypsum is generally secured from naturally occuring deposits in the earth In natural gypsum deposits, it is most useful to scan the source for naturally occurring anhydrite(CaSO4)gypsum deposits, it is most useful to scan the source for naturally occurring anhydrite(CaSO4) or anhydrous calcium sulfate. Since this form of calcium sulfate is not as readily soluble in wateror anhydrous calcium sulfate. Since this form of calcium sulfate is not as readily soluble in water as is gypsum (CaSO4• 2H2O), anhydrite can fail to control concrete setting appropriately. Inas is gypsum (CaSO4• 2H2O), anhydrite can fail to control concrete setting appropriately. In addition, anhydrite is much harder than gypsum and will not be ground as fine during finishaddition, anhydrite is much harder than gypsum and will not be ground as fine during finish grinding; this will also reduce its rate of solubility. For these reasons, sources of gypsumgrinding; this will also reduce its rate of solubility. For these reasons, sources of gypsum containing high amounts of anhydrite are usually avoided. However, if the finish millcontaining high amounts of anhydrite are usually avoided. However, if the finish mill temperature is very high, dehydration of gypsum might produce too much hemihydrate (CaSO4•temperature is very high, dehydration of gypsum might produce too much hemihydrate (CaSO4• 1⁄2H2O), there by causing false set. In such a case, it may be desirable to add some of the1⁄2H2O), there by causing false set. In such a case, it may be desirable to add some of the needed calcium sulfate as anhydrite. XRD provides a quick method to detect anhydrite togetherneeded calcium sulfate as anhydrite. XRD provides a quick method to detect anhydrite together with coexisting gypsum,hemihydrate, and minor contamination such as calcite and quartz.with coexisting gypsum,hemihydrate, and minor contamination such as calcite and quartz. Figure shows an XRD pattern of a gypsum source. Naturally occurring anhydrite, sometimesFigure shows an XRD pattern of a gypsum source. Naturally occurring anhydrite, sometimes referred to as “insoluble” anhydrite, differs from “soluble” anhydrite in that they have differentreferred to as “insoluble” anhydrite, differs from “soluble” anhydrite in that they have different crystalline arrangements and therefore have slightly different solubility in water. “Soluble”crystalline arrangements and therefore have slightly different solubility in water. “Soluble” anhydrite can result, for instance when gypsum is exposed to temperatures above aroundanhydrite can result, for instance when gypsum is exposed to temperatures above around 200°C and loses its chemically bound water. This compound is not200°C and loses its chemically bound water. This compound is not
  42. 42. XRD pattern of gypsum rock source for addition to clinker in cementXRD pattern of gypsum rock source for addition to clinker in cement grinding. In addition to gypsum (reference lines shown), phases identifiedgrinding. In addition to gypsum (reference lines shown), phases identified include hemihydrate (Hh) and quartz (Qz). It must be noticed thatinclude hemihydrate (Hh) and quartz (Qz). It must be noticed that hemihydrate does not usually occur naturally. Its presence in this patternhemihydrate does not usually occur naturally. Its presence in this pattern may result from sample preparation.may result from sample preparation.
  43. 43. Uses of XRD & XRF:Uses of XRD & XRF: • easily distinguished from plaster by XRD in gypsum sources but is rapidly soluble andeasily distinguished from plaster by XRD in gypsum sources but is rapidly soluble and usually causes no interference in controlling concrete setting.usually causes no interference in controlling concrete setting. • Coal CharacterizationCoal Characterization • The principal solid fuel used in cement manufacture is coal. In addition to clayThe principal solid fuel used in cement manufacture is coal. In addition to clay minerals, common impurities in coal are carbonates, iron sulfides such as pyriteminerals, common impurities in coal are carbonates, iron sulfides such as pyrite (FeS2) and other sulfides, chlorides ,and quartz (Bye, 1999). XRD is a useful tool for(FeS2) and other sulfides, chlorides ,and quartz (Bye, 1999). XRD is a useful tool for detecting these compounds. Sulfides and chlorides can cause a variety of problemsdetecting these compounds. Sulfides and chlorides can cause a variety of problems when coal is burned in the kiln or in the calciner. The use of coals(and fuels inwhen coal is burned in the kiln or in the calciner. The use of coals(and fuels in general) is limited by the total sulfur content, and some sulfur is in the form ofgeneral) is limited by the total sulfur content, and some sulfur is in the form of crystalline sulfides, XRD will be a useful tool for detecting these compounds.crystalline sulfides, XRD will be a useful tool for detecting these compounds. Chlorides also may be present in crystalline structures like sylvite or halite that canChlorides also may be present in crystalline structures like sylvite or halite that can easily be detected by XRD. Pyrite is found in coal as a common impurity and in someeasily be detected by XRD. Pyrite is found in coal as a common impurity and in some limestone deposits as well. Its XRD peaks are located at 33.0X, 56.27, 37.15, andlimestone deposits as well. Its XRD peaks are located at 33.0X, 56.27, 37.15, and 40.74 °2θ.40.74 °2θ.
  44. 44. Uses of XRD & XRF:Uses of XRD & XRF: • Dolomitic LimestonesDolomitic Limestones Dolomite (CaMg(CO3)2) has limited use in cement manufacturing because the clinkerDolomite (CaMg(CO3)2) has limited use in cement manufacturing because the clinker resulting from its use would be excessively high in free MgO or periclase upon clinkerresulting from its use would be excessively high in free MgO or periclase upon clinker cooling. Potential problems may arise with these cements because of their excessivecooling. Potential problems may arise with these cements because of their excessive expansion. However, some cement producers have dealt with high MgO clinkers byexpansion. However, some cement producers have dealt with high MgO clinkers by adjusting the raw mix chemistry to produce a clinker with a lower MgO/Fe2O3 ratio.adjusting the raw mix chemistry to produce a clinker with a lower MgO/Fe2O3 ratio. As a rule of thumb, when this ratio is lower, more MgO can be tolerated without failingAs a rule of thumb, when this ratio is lower, more MgO can be tolerated without failing the autoclave expansion test. At certain cement-making locations the only limestonethe autoclave expansion test. At certain cement-making locations the only limestone readily available may contain appreciable dolomite, and in such cases, carefulreadily available may contain appreciable dolomite, and in such cases, careful characterization of the limestone is required. In the example shown in Figure, thecharacterization of the limestone is required. In the example shown in Figure, the limestone contains a rather high proportion of dolomite, whose XRD reference lineslimestone contains a rather high proportion of dolomite, whose XRD reference lines are shown in the pattern. A cement or clinker suspected of containing high MgOare shown in the pattern. A cement or clinker suspected of containing high MgO should be analyzed by XRD. Chemical analysis is also desirable. Clinkers or cementsshould be analyzed by XRD. Chemical analysis is also desirable. Clinkers or cements high in MgO may contain as much as 8% or as little as 3.5% periclase by mass.high in MgO may contain as much as 8% or as little as 3.5% periclase by mass. Figure shows a clinker sample with an unusual amount of periclase, readily identifiedFigure shows a clinker sample with an unusual amount of periclase, readily identified by the diffraction line at 42.9 °2θ.by the diffraction line at 42.9 °2θ.
  45. 45. XRD pattern of a sample of limestone high in dolomite used asXRD pattern of a sample of limestone high in dolomite used as a source in cement manufacturing. Reference lines for dolomitea source in cement manufacturing. Reference lines for dolomite are shown. Labels for quartz (Qz) and calcite (Cc)main peaksare shown. Labels for quartz (Qz) and calcite (Cc)main peaks are also shown.are also shown.
  46. 46. XRD pattern of cement containing free MgO or crystallineXRD pattern of cement containing free MgO or crystalline Periclase (reference lines shown). The oxide analysis reported aPericlase (reference lines shown). The oxide analysis reported a total MgO of 3.9 wt.%.total MgO of 3.9 wt.%.
  47. 47. Uses of XRD & XRF:Uses of XRD & XRF: • ClayClay • Clay materials from quarries used in cement manufacturing normally occur togetherClay materials from quarries used in cement manufacturing normally occur together with feldspars,quartz, and carbonates (calcite or dolomite). The XRD is an essentialwith feldspars,quartz, and carbonates (calcite or dolomite). The XRD is an essential tool, aided by optical microscopy and chemical analysis, to characterize and identifytool, aided by optical microscopy and chemical analysis, to characterize and identify clay components in cement raw materials. Clay minerals have a layered crystalclay components in cement raw materials. Clay minerals have a layered crystal structure and often occur as thin sheets parallel to these crystal layers. Clays arestructure and often occur as thin sheets parallel to these crystal layers. Clays are often poorly crystalline and often occur as very small grains. For these reasons, theiroften poorly crystalline and often occur as very small grains. For these reasons, their basal peak (from the crystal layer) is often the only recognizable peak and may bebasal peak (from the crystal layer) is often the only recognizable peak and may be quite broad. The d-spacing of the basal peak is usually quite broad, a feature that isquite broad. The d-spacing of the basal peak is usually quite broad, a feature that is very helpful for their identification in the presence of minerals like quartz, feldspars, orvery helpful for their identification in the presence of minerals like quartz, feldspars, or carbonates. For instance, a diffraction peak at 12.3 °2θ identifies kaolinite, usuallycarbonates. For instance, a diffraction peak at 12.3 °2θ identifies kaolinite, usually indicative of kaolin clay present in the overburden of limestone quarries. Another clayindicative of kaolin clay present in the overburden of limestone quarries. Another clay commonly found is illite. An example of the XRD pattern on clay minerals identifiedcommonly found is illite. An example of the XRD pattern on clay minerals identified ina clay source for cement manufacturing is shown in Figure.ina clay source for cement manufacturing is shown in Figure.
  48. 48. XRD pattern showing clay minerals identified on a clay sourceXRD pattern showing clay minerals identified on a clay source for cement manufacturing. Cc: calcite, Qz: quartz, Mm:for cement manufacturing. Cc: calcite, Qz: quartz, Mm: montmorillonite, Ch: chlorite,Ab:montmorillonite, Ch: chlorite,Ab: albite, Mt: margarite.albite, Mt: margarite.
  49. 49. Uses of XRD & XRF:Uses of XRD & XRF: • LimestoneLimestone • Limestone is the main raw material used in cement manufacturing. It comprises fromLimestone is the main raw material used in cement manufacturing. It comprises from 70% to 95% of the raw meal fed to the kiln. Calcite (CaCO3) is normally the most70% to 95% of the raw meal fed to the kiln. Calcite (CaCO3) is normally the most abundant phase in limestone; its strongest diffraction peak is produced at 29.4 °2θabundant phase in limestone; its strongest diffraction peak is produced at 29.4 °2θ with Cu Kα radiation6. Quartz, feldspars, and clay minerals are normally present aswith Cu Kα radiation6. Quartz, feldspars, and clay minerals are normally present as minor contaminants in limestone deposits. Dolomite is also found in small amounts inminor contaminants in limestone deposits. Dolomite is also found in small amounts in some limestones , as discussed later in this section. Figure shows a typical XRDsome limestones , as discussed later in this section. Figure shows a typical XRD pattern of limestone.pattern of limestone.
  50. 50. XRD pattern of a limestone sample from a quarry. CalciteXRD pattern of a limestone sample from a quarry. Calcite (reference linesshown7) and quartz detected as main phases.(reference linesshown7) and quartz detected as main phases. Aluminum line from sample holder is also shownAluminum line from sample holder is also shown as an artifact.as an artifact.
  51. 51. Uses of XRD & XRF:Uses of XRD & XRF: • BauxiteBauxite • Bauxite may be used in cement manufacturing in cases where lime and/or silicaBauxite may be used in cement manufacturing in cases where lime and/or silica sources do not provide enough Al2O3 for the desired clinker formulation. Bauxite’ssources do not provide enough Al2O3 for the desired clinker formulation. Bauxite’s mineralogical composition also includes different polymorphs of aluminum oxide andmineralogical composition also includes different polymorphs of aluminum oxide and hydroxide, such as gibbsite, norstrandite, and bayerite, which are readily identifiablehydroxide, such as gibbsite, norstrandite, and bayerite, which are readily identifiable by XRD. Bauxite may also contain hematite and magnetite, which incorporate ironby XRD. Bauxite may also contain hematite and magnetite, which incorporate iron into the clinker. Corundum (Al2O3), is also readily identifiable. It is a very hardinto the clinker. Corundum (Al2O3), is also readily identifiable. It is a very hard mineral and its identification is a decisive factor for raw feed grindabilitymineral and its identification is a decisive factor for raw feed grindability considerations. Al(OH)3, as the main phase in the sample. particular sample isconsiderations. Al(OH)3, as the main phase in the sample. particular sample is primarily composed of a mixture of gibbsite (reference lines shown) and hematiteprimarily composed of a mixture of gibbsite (reference lines shown) and hematite (peaks at 33.1X, 35.67, 24.13 °2θ). It also contains anatase (TiO2), aluminum oxide(peaks at 33.1X, 35.67, 24.13 °2θ). It also contains anatase (TiO2), aluminum oxide hydroxide, or boehmite (Al O(OH)), and traces of calcite, quartz, and kaolinite.hydroxide, or boehmite (Al O(OH)), and traces of calcite, quartz, and kaolinite.
  52. 52. Bauxite alternative alumina source for cement manufacturing.Bauxite alternative alumina source for cement manufacturing. Reference lines shown identify gibbsite as the main crystallineReference lines shown identify gibbsite as the main crystalline component in the sample.component in the sample.
  53. 53. XRD graph of an alternative alumina source for cementXRD graph of an alternative alumina source for cement manufacturing. The sample consists of a mixture of gibbsite andmanufacturing. The sample consists of a mixture of gibbsite and hematite. Reference lines shown identify gibbsite.hematite. Reference lines shown identify gibbsite.
  54. 54. Bauxite PlotBauxite Plot
  55. 55. Clay PlotClay Plot
  56. 56. Gypsum PlotGypsum Plot
  57. 57. Laterite PlotLaterite Plot
  58. 58. Limestone PlotLimestone Plot
  59. 59. Sand stone Low PuritySand stone Low Purity
  60. 60. Sand stone High PuritySand stone High Purity
  61. 61. Raw Mix Quartz TestRaw Mix Quartz Test

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