Contents Acknowledgements xvii Preface xix Editor’s foreword xxi 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 Powder sampling Introduction Sample selection Sampling stored material 1.3.1 Sampling stored non-flowing material 1.3.2 Sampling from heaps 1.3.3 Sampling stored bulk free-flowing powders 1.3.4 Sampling from sacks and drums 1.3.5 Sampling from trucks and railcars Sampling flowing streams 1.4.1 Sampling from a conveyor belt 1.4.2 Point samplers 1.4.3 Sampling from falling streams 1.4.4 Stream sampling ladles 1.4.5 Traversing cutters 1.4.6 Sampling dusty material 1.4.7 In-line sampling Sample reduction 1.5.1 Scoop sampling 1.5.2 Cone and quartering 1.5.3 Table sampling 1.5.4 Chute splitting 1.5.5 Spinning rifflers 1.5.6 Commercial rotary sample dividers 1.5.7 Miscellaneous sampling devices Slurry sampling Reduction of laboratory sample to measurement sample Number of samples required Theoretical statistical errors on a number basis Practical statistical errors on a number basis Theoretical statistical errors on a weight basis Practical statistical errors on a weight basis Experimental tests of sampling techniques 1 2 6 7 9 10 11 12 12 13 14 14 18 19 19 23 24 25 26 27 27 28 30 30 35 36 38 42 45 46 46 49 vi Contents 1.14 Weight of sample required 1.14.1 Gross sample 1.14.2 Sampling by increments 2 2.1 2.2 2.3 2.4 2.5 Data presentation and interpretation Introduction Particle size Average diameters Particle dispersion Particle shape 2.5.1 Shape coefficients 2.5.2 Shape factors 2.5.3 Applications of shape factors and shape coefficients 2.5.4 Shape indices 2.5.5 Shape regeneration 2.5.6 Fractal dimensions characterization of textured surfaces 2.5.7 Other methods of shape analysis 2.5.8 Sorting by shape Determination of specific surface from size distribution data 2.6.1 Determination of specific surface from a number count 2.6.2 Determination of specific surface from a surface count Tabular presentation of particle size distribution Graphical presentation of size distribution data 2.8.1 Presentation on linear graph paper Standard forms of distribution functions Arithmetic normal distribution 2.10.1 Manipulation of the normal equation The log-normal distribution 2.11.1 Relationship between number mean sizes for a lognormal distribution 2.11.2 Derived mean sizes 2.11.3 Transformation between log-normal distributions 2.11.4 Relationship between median and mode of a lognormal equation 2.11.5 An improved equation and graph paper for log-normal evaluations 2.11.6 Application Johnson's SB distribution Rosin-Rammler-Bennet-Sperling formula Other distribution laws 2.14.1 Simplification of two parameter equations. 2.14.2 Comments The law of compensating errors Evaluation of nonlinear distributions on log-normal paper 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 50 50 51 56 57 63 68 69 74 76 78 82 83 84 88 88 89 89 90 93 95 95 96 96 99 100 102 105 106 107 108 109 109 111 112 112 114 117 117 Contents vii 2.17 2.18 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 2.16.1 Bimodal intersecting distributions. 2.16.2 Bimodal non- intersecting distributions. 2.16.3 Other distributions 2.16.4 Applications of log-normal plots 2.16.5 Curve fitting 2.16.6 Data interpretation Alternative notations for frequency distribution 2.17.1 Notation 2.17.2 Moment of a distribution 2.17.3 Transformation from qt(x) to qr(x) 2.17.4 Relation between moments 2.17.5 Means of distributions 2.17.6 Standard deviations 2.17.7 Coefficient of variation 2.17.8 Applications 2.17.9 Transformation of abscissae Phi-notation Particle size analysis by image analysis Introduction Standards Optical microscopy 3.3.1 Upper size limit for optical microscopy 3.3.2 Lower size limit for optical microscopy Sample preparation Measurement of plane sections through packed beds Particle size Calibration 3.7.1 Linear eyepiece graticules 3.7.2 Globe and circle graticules Training of operators Experimental techniques Determination of particle size distribution by number Conditions governing a weight size determination 3.11.1 Illustrative example of the calculation of a size distribution by weight Semi-automatic aids to microscopy Automatic aids to microscopy 3.13.1 Beckman Coulter RapidVUE 3.13.2 Micromeretics OptiSizer PSDA™ 5400 3.13.3 Oxford VisiSizer 3.13.4 Retsch Camsizer 3.13.5 Malvern Sysmex Flow Particle Image Analyzer FPIA-2100 automated particle shape and size analyzer 3.13.6 Sci-Tec PartAn - video Image Analyser 117 122 122 123 123 125 125 125 126 126 127 128 129 130 130 132 136 142 144 145 145 146 147 151 151 153 154 154 156 157 158 160 162 164 167 167 167 168 168 168 169 viii Contents 3.14 3.15 3.16 3.17 3.18 3.19 3.20 Quantitative image analysis 3.14 1 Calibration of image analyzers 3.14.2 Experimental procedures 3.14.3 Commercial quantitative image analysis systems 3.14.4 Confocal laser-scanning microscopy 3.14.5 On-line microscopy 3.14.6 Flatbed scanners 3.14.7 Dark field microscopy 3.14.8 Phase contrast microscopy 3.14.9 Polarized light microscopy (PLM) 3.14.10 Dipix 1440F power scope imaging microscope 3.14.11 Transmission wide field phase contrast microscopy Electron microscopy Transmission electron microscopy (TEM) 3.16.1 Specimen preparation for TEM 3.16.2 Replica and shadowing techniques 3.16.3 Chemical analysis Scanning electron microscopy Other scanning electron microscopy techniques Errors involved in converting a number to a volume count Evaluation of procedures 4 Particle size analysis by sieving 4.1 Introduction 4.2 Standard sieves 4.3 Tolerances for standard sieves 4.4 Woven-wire and punched plate sieves 4.5 Electroformed micromesh sieves 4.6 Mathematical analysis of the sieving process 4.7 Calibration of sieves 4.8 Sieving errors 4.9 Methods of sieving 4.10 Amount of sample required 4.11 Hand sieving 4.12 Machine sieving 4.13 Wet sieving 4.13.1 Manual 4.13.2 Wet sieving by machine 4.14 Air-jet sieving 4.15 The Sonic Sifter 4.16 The Seishin Robot Sifter 4.17 Automatic systems 4.17.1 The Rotex Gradex 2000 particle size analyzer 4.17.2 Labcon automatic sieve system 4.17.3 Gilson Compu-Sieve« analysis system 169 170 170 180 183 184 185 185 186 186 187 187 187 188 188 192 192 193 196 199 200 208 210 212 213 214 218 221 224 227 229 230 231 234 234 235 237 239 239 240 240 241 241 Contents ix 4.18 4.19 4.20 4.21 4.22 4.23 4.24 Ultrasonic sieving The sieve cascadograph Felvation Self organized sieves (SORSI) Shape separation Correlation with light scattering data Conclusions 5 5.1 5.2 5.3 5.4 Fluid classification Introduction Assessment of classifier efficiency Systems Counter-flow equilibrium classifiers in a gravitational field elutriators Theory for elutriators Water elutriators Air elutriators Counter-flow centrifugal classifiers; Zig-zag gravitational classifiers Zig-zag centrifugal classifiers The Warmain Cyclosizer Cross-flow gravitational classification 5.12.1 The Humboldt particle size analyzer TDS Cross-flow centrifugal classifiers 5.13.1 Analysette 9 5.13.2 The Donaldson Acucut classifier Cross-flow elbow classifier Micromeretics classifier; Fractionation methods for particle size measurement Hydrodynamic chromatography Capillary hydrodynamic fractionation ; Capillary zone electrophoresis Size exclusion chromatography Field flow fractionation 5.21.1 Sedimentation field flow fractionation (SFFF) 5.21.2 Centrifugal field flow fractionation 5.21.3 Time-delayed exponential SFFF 5.21.4 Thermal field flow fractionation 5.21.5 Magnetic field flow fractionation 5.21.6 Flow field flow fractionation 5.21.7 Steric field flow fractionation 5.21.8 Multi-angle light scattering (MALS) The Matec electro-acoustic system EAS-8000 Continuous split fractionation Classification by decantation; 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 241 241 243 243 244 245 245 251 251 260 261 262 264 265 266 267 267 268 268 268 269 269 269 270 270 271 272 275 276 276 277 278 279 279 282 282 282 284 284 285 285 287 x Contents Interaction between particles and fluids 6.1 Introduction 6.2 Settling of a single homogeneous sphere under a gravitational force 6.2.1 Relationship between settling velocity and particle size 6.2.2. Calculation of particle size from settling velocity in the laminar flow region 6.3 Size limits for gravity sedimentation 6.3.1 Upper size limit 6.3.2 Lower size limit 6.4 Time for terminal velocity to be attained 6.5 Errors due to the finite extent of the fluid (wall effects) 6.6 Errors due todiscontinuity of the fluid 6.7 Viscosity of a suspension 6.8 Non-rigid spheres 6.9 Non-spherical particles 6.9.1 Stokes' region 6.9.2 Relationship between fiber diameter and Stokes diameter 6.9.3 Transition region 6.10 Relationship between drag coefficient and Reynolds number in the transition region 6.11 The turbulent flow region 6.12 Concentration effects 6.13 Hindered settling 6.13.1 Low concentration effects 6.13.2 High concentration effects 6.14 Electro-viscosity 6.15 Dispersion of powders 6.15.1 Dry powder dispersion 6.15.2 The use of glidants to improve flowability of dry powders 6.15.3 Wet powder dispersion 6.15.4 Role of dispersing agents 6.15.5 Wetting a powder 6.15.6 Determination of contact angle () 6.15.7 Deagglomerating wetted clumps 6.15.8 Suspension stability 6.15.9 Tests of dispersion quality 6.16 Powder density 6.17 Liquid viscosity 6.18 Standard powders 6.19 National Standards 295 295 297 297 299 300 301 302 306 308 309 311 312 312 312 317 319 322 325 326 332 333 334 335 336 336 337 338 338 339 340 342 343 344 347 350 350 352 Contents xi 7 Gravitational sedimentation methods of particle size determination 7.1 Introduction 7.2 Resolution of sedimenting suspensions 7.3 Concentration changes in a suspension settling under gravity 7.4 Homogeneous incremental gravitational sedimentation 7.4.1 The pipette method of Andreasen 7.5 Theory for the gravity photosedimentation technique 7.5.1 The Beer Lambert law 7.5.2 The extinction coefficient 7.5.3 Turbidity measurements (Turbidimetry) 7.5.4 The photosedimentation technique 7.5.5 Commercial photosedimentometers 7.5.6 Sedimentation image analysis 7.5.7 Transmission fluctuation spectrometry 7.6 Theory for concentration determination with the x-ray gravitational sedimentation technique 7.6.1 X-ray sedimentation 7.7 Relationship between density gradient and concentration 7.8 Hydrometers and divers 7.8.1 Introduction 7.8.2 Theory 7.8.3 Depth of immersion 7.8.4 Experimental procedure 7.8.5 Divers 7.9 Homogeneous cumulative gravitational sedimentation 7.9.1 Introduction 7.9.2 Theory 7.9.3 Sedimentation balances 7.9.4 Sedimentation columns 7.10 Line-start incremental gravitational sedimentation 7.10.1 Photosedimentation 7.11 Line-start cumulative gravitational sedimentation 7.11.1 Introduction 7.11.2 Methods 8 8.1 8.2 8.3 8.4 Centrifugal sedimentation methods of particle size determination Introduction Stokes' equation for centrifugal sedimentation 8.2.1 General theory Homogeneous, incremental, centrifugal sedimentation 8.3.1 General theory Variable time method (r and S constant, t variable) 8.4.1 General theory 359 362 364 365 365 366 366 369 370 370 372 373 374 374 375 378 379 379 380 381 383 384 384 384 384 386 387 387 387 388 388 388 392 394 394 395 395 397 397 xii Contents 8.4.2 8.16 8.17 8.18 8.19 The Simcar pipette disc centrifuge (r constant, S assumed constant, t variable) 8.4.3 Worked example 8.4.4 The Ladal x-ray disc centrifuge(r constant, S constant, t variable) 8.4.5 Discussion of the Kamack equation Variable time and height method (S constant, both r and t vary) 8.5.1 Stokes diameter determination 8.5.2 Mass frequency undersize determination 8.5.3 DuPont/Brookhaven scanning x-ray disc centrifugal sedimentometer 8.5.4 Worked example Variable inner radius (Both S and t vary, r remains constant) 8.6.1 Stokes diameter determination 8.6.2 Ladal pipette disc centrifuge 8.6.3 Worked example 8.6.4 Mass frequency undersize determination Photocentrifuges 8.7.1 Introduction 8.7.2 Disc photocentrifuges. 8.7.3 Homogeneous mode Line-start incremental centrifugal sedimentation 8.8.1 Line-start, incremental centrifugal technique 8.8.2 Discussion of line-start theory 8.8.3 BI-DCP disc (photo)centrifuge particle size analyzer Cuvette photocentrifuges Homogeneous, cumulative, centrifugal sedimentation 8.10.1 General theory Variable time method (variation of P with t) Sedimentation distance small compared with distance from centrifuge axis 8.12.1 Hosokawa Mikropul Sedimentputer 8.12.2 Alpine long-arm centrifuge Variable inner radius (variation of P with S) 8.13.1 Alternative theory (variation of P with S) Variable outer radius (variation of P with R) Line-start cumulative centrifugal sedimentation 8.15.1 MSA analyzer Particle size analysis using non-invasive dielectric sensors Supercentrifuge Ultracentrifuge Conclusions 9 9.1 Stream scanning methods of particle size measurement Introduction 8.5 8.6. 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15 403 404 406 406 406 406 407 407 408 410 410 412 413 415 417 417 418 419 422 422 425 428 429 431 431 433 434 434 435 435 437 438 439 439 439 440 442 442 447 Contents xiii 9.2 9.3 9.4 9.5 9.6 The electrical sensing zone method (the Coulter principle) 9.2.1 Introduction 9.2.2 Operating principle 9.2.3 Theory for the electrical sensing zone method 9.2.4 Effect of particle shape and orientation 9.2.5 Pulse shape 9.2.6 Effect of coincidence 9.2.7 Multiple aperture method for powders having a wide size range 9.2.8 Calibration 9.2.9 Carrying out a mass balance 9.2.10 Oversize counts on a mass basis using the Coulter Counter 9.2.11 Apparatus 9.2.12 Limitations of the method Fiber length analysis Optical particle counters 9.4.1 Light blockage 9.4.2 Optical disdrometer 9.4.3 Light scattering Commercial instruments 9.5.1 Aerometrics 9.5.2 Canty Vision 9.5.3 Climet 9.5.4 Contamination Control Systems 9.5.5 Danfoss VisionSensor 9.5.6 Faley Status 9.5.7 Flowvision 9.5.8 Galai 9.5.9 Kane May 9.5.10 Kowa 9.5.11 Kratel 9.5.12 Malvern 9.5.13 Pacific Scientific Hiac/Royco, Met One 9.5.14 Particle Measuring Systems 9.5.15 Partikel Messetechnik 9.5.16 Particle Sizing Systems 9.5.17 Polytec 9.5.18 Rion 9.5.19 Spectrex Dwell time 9.6.1. Brinkmann 201 analyzer 9.6.2 Focused Beam Reflectance Measurement (FBRM) Lasentec 9.6.3 Messetechnik Optical Reflectance Method (ORM) 449 449 450 452 455 457 459 460 461 463 464 465 466 467 468 469 470 470 474 474 474 474 475 476 476 476 477 478 478 478 479 480 484 486 486 488 488 489 492 492 493 496 xiv Contents 9.7 9.8 9.9 9.10 9.11 9.12 9.13 9.14 9.15 9.16 9.17 9.18 9.19 9.20 10 10.1 10.2 10.3 9.6.4 Procedyne Aerodynamic time-of-flight measurement 9.7.1 Thermo Systems Incorporated 9.7.2 Ancillary equipment Laser Doppler velocimetry (LDV) Laser phase Doppler principle 9.9.1 TSI Aerometrics phase Doppler particle analyzer 9.9.2 Discusion 9.9.3 Differential phase-Doppler anemometry 9.9.4 Bristol Industrial Research Association 9.9.5 Dantec Particle Dynamic Analyzer Hosokawa Mikropul E-Spart Analyzer Shadow Doppler velocimetry Other light scattering methods Interferometers 9.13.1 Mach Zehnder type interferometer 9.13.2 The TSI Liquitrak™ interferometer Flow ultramicroscope. 9.14.1 ISPA image analysis system Measurement of the size distribution of drops in dispersions Dupont electrolytic grain size analyzer Light pressure drift velocity Impact size monitor Monitek acoustic particle monitors Erdco Acoustical Counter 497 497 497 500 501 501 502 502 503 504 504 505 506 507 508 508 509 510 510 510 512 512 513 513 514 Field scanning methods of particle size measurement Introduction Single point analyzers 10.2.1 Static noise measurement 10.2.2 Ultrasonic attenuation 10.2.3 -ray attenuation 10.2.4 X-ray attenuation and fluorescence 12.2.5 Counter-flow classifiers 10.2.6 Hydrocyclones 10.2.7 The Cyclosensor 10.2.8 Automatic sieving machines 10.2.9 Gas flow permeametry 10.2.10 Correlation techniques Light scattering and attenuation 10.3.1 Introduction 10.3.2 Effect of extinction coefficient on turbidity 10.3.3 Transient turbidity 10.3.4 Holography 10.3.5 State of.polarization of the scattered radiation 524 525 525 526 527 527 527 528 528 529 530 531 531 531 532 535 536 537 Contents xv 10. 4 10.5 10.6 10.7 10.8 10.9 10.10 10.11 10.12 10.13 10.14 10.3.6 Forward/backward intensity ratio (FBR) 10.3.7 Optical back-scattering 10.3.8 Transmission fluctuation spectroscopy Light scattering theory 10.4.1 The Rayleigh region (d) 10.4.2 The Rayleigh-Gans region (D < ) 10.4.3 High order Tyndall spectra (HOTS) 10.4.4 Light diffraction 10.4.5 Early commercial light scattering equipment Multi angle laser light scattering; (MALLS) 10.5.1 Theoretical basis for MALLS instruments 10.5.2 Commercial instruments 10.5.3. Discussion Malvern (Insitec) Ensemble Particle Concentration Size (EPCS) Systems Optical incoherent space frequency analysis 10.7.1 Retsch Crystalsizer Pulse displacement technique (PDT) Small angle x-ray scattering (SAXS) Near infra-red spectroscopy (NIR) Ultrasonic attenuation 10.11.1 Introduction 10.11.2 Theoretical basis for ultrasonic instruments 10. 11.3 Discussion Matec Acoustosizer (ACS) Ultrasonic attenuation and velocity spectrometry Photon correlation spectroscopy (PCS) 10.14.1 Introduction 10.14.2 Principles 10.14.3 Through dynamic light scattering 10.14.4 Particle size 10.14.5 Concentration effects 10.14.6 Particle interaction 10.14.7 Particle size effects 10.14.8 Polydispersity 10.14.9 The controlled reference method 10.14.10 Multi-angle measurements 10.14.11 Commercial equipment 10.14.12 Discussion 10.14.13 Spectral turbidity 10.14.14 Diffusion wave spectroscopy (DWS) 10.14.15 Photon migration 10.15 Turbo-Power Model TPO-400 in-line grain size analyzer 10.16 Concentration monitors 538 539 539 539 539 540 542 543 543 544 547 552 563 568 572 573 574 575 576 576 576 576 581 584 584 586 586 587 588 589 590 590 591 591 593 594 596 601 602 603 603 603 603 xvi Contents 10.17 Shape discrimination 10.18 Miscellaneous 10.18.1 Back-scatter intensity 10.18.2 Spectroscopy; photo-acoustic (PAS) and photo-thermal (PTS) 10.18.3 Transient electric birefringence 10.18.4 Crossed lasers 10.18.5 Frequency domain photon migration 10.18.6 Laser induced incandescence (LII) 10.18.7 Spectral transmission and extinction 10.18.8 Turbiscan multiple light scattering measurements 604 604 604 Appendix 623 Manufacturers and suppliers 605 605 606 606 607 607 608 Author index 628 Subject index 651