Nuclear Geophysics (eBook)

Front Cover 1
Nuclear Geophysics: Selected Papers on Applications of Nuclear Techniques in Mineral Exploration, Mining and Process Control 4
Copyright Page 5
Table of Contents 6
EDITORIAL 10
Chapter 1. Coal Analysis by Nuclear Methods 12
1. Introduction 12
2. Some General Characteristics of Nuclear Methods 13
3. Low Energy x-Ray Scattering 15
4. .-Ray Scattering 19
5. Neutron Interaction Analysis 21
6. Conclusions 31
References 31
Chapter 2. Natural . -Radiation: A Steering Guide in Coal Seams 32
1. Introduction 32
2. Laboratory Analysis of the Technique 33
3. Coal Face Measurements 37
4. Some Features of Sensor Design and Performance 40
5. Conclusions 43
References 43
Chapter 3. Feasibility Studies of Low Energy . -Ray Techniques for On-line Determination of Ash Content of Coal on Conveyors 46
1. Introduction 46
2. Calculations for Narrow Beam Transmission Geometry 47
3. Experimental 48
4. Results and Discussion 50
5. Implications 52
6. Conclusion 53
References 53
Chapter 4. A Technique for Measuring the Ash Content of Coal in a Tailings Stream 54
1. Introduction 54
2. Method of Measurement 54
3. Re-circulating Slurry Loop 55
4. Interference Effects in the Backscatter Energy Window 56
5. Coal Slurry Samples 57
6. Experimental Procedure with the Slurry Loop 57
7. Results 58
8. Data Handling and Accuracy 59
9. Equivalent Error in Ash Due to Counting Statistics 62
10. Conclusion 63
Chapter 5. Determination of Solids Weight Fraction and Mineral Matter or Ash Concentration of Coal in Slurries 64
1. Introduction 64
2. Determination of Solids Weight Fraction 64
3. Determination of Solids Weight Fraction of Coal Slurries 65
4. Determination of Mineral Matter Content of Coal in Slurries 67
5. Discussion 70
6. Conclusion 70
References 70
Chapter 6. On-line Determination of the Ash Content of Coal Using a "Siroash" Gauge Based on the Transmission of Low and High Energy y-Rays 72
1. Introduction 72
2. Description of the Method 72
3. Sources of Error 74
4. Field Trial at the Gregory Mine 75
5. Results 76
6. Discussion 78
7. Conclusion 78
References 78
Chapter 7. In-Situ Analysis of Coal by Measurement of Neutron-Induced Prompt . -Rays 80
1. Introduction 80
2. Fundamental Principles 81
3. Theoretical Treatment of the Method of Analysis 85
4. Experimental Investigations 88
5. Conclusions 91
References 91
Chapter 8. Multi-element Analysis of Coal During Borehole Logging by Measurement of Prompt . -Rays from Thermal Neutron Capture 92
1. Introduction 92
2. Experimental Procedures 93
3. Results 94
4. Discussion 100
5. Conclusions 101
References 101
Chapter 9. Nuclear Geophysics in Prospecting, Exploration and Development of Oil and Gas Fields 104
Introduction 104
1. Nuclear-Geophysical Parameters as the Basis for Rock Measurements 104
2. Classification of the Nuclear-Geophysical Methods and their Relationship with Sedimentary Rock Physical Properties 106
3. Nuclear-Geophysical Methods 107
4. Major Development Trends in Apparatus Design 114
5. Problems Which can be Solved by Nuclear Geophysical Methods 117
Conclusions 125
References 125
Chapter 10. Stochastic Approach to the Pulsed Neutron Logging Methods 128
1. Introduction 128
2. General Outline 128
3. Stochastic Process Approach 129
4. Estimation Problems 131
5. Nuclear Phenomena Involved in Neutron Logging 132
6. Direct Nuclear Well Logging Considerations 134
7. Final Remarks and Conclusions 137
References 137
Chapter 11. The Use of Steady State Neutron Flux Measurement to Determine the Size of an Invaded Region Following Fluid Injection 138
1. Introduction 138
2. Theory 138
3. Results 140
4. Discussion 143
5. Conclusions 144
References 144
Chapter 12. The Reduction of the Influence of Formation Properties on the Calibration of a Prompt . -Ray Interaction Analysis Probe 146
1. Introduction 146
2. Theory 146
3. Results 148
4. Discussion 150
5. Conclusions 151
References 151
Chapter 13. Measurement of the Thermal Neutron Absorption Cross Section of Rock Samples 152
1. Introduction 152
2. Principles 152
3. Experimental Set-up 155
4. Experimental Results 155
5. Final Remarks 159
References 160
Chapter 14. Advances in Gamma–Gamma Logging 162
1. Introduction 162
2. Physical Considerations 162
3. Calibration Curves 173
4. Applications 177
5. Future Development 180
6. Final Remarks and Conclusions 180
References 181
Chapter 15. The Application of Monte Carlo Computations to Formation Analysis by Neutron Interactions 182
1. Introduction 182
2. Basic Studies 184
3. Analysis by . -Rays from Neutron Interactions 196
4. Log Interpretation 203
5. Conclusions 207
References 207
Chapter 16. Airborne . -Ray Spectrometry in Uranium Exploration. Principles and Current Practice 208
1. Introduction 208
2. The Naturally Occurring Radioisotopes 208
3. Geological Considerations 210
4. Factors Affecting the Radiation Flux Received by an Airborne . -Ray Spectrometer 215
5. Factors Dependent on Equipment Configuration and Performance Which Affect Spectrometric Data 215
6. Spectrometer Calibration and Primary Corrections Normally Applied to Spectrometric Data 216
7. Instrumentation Used in Airborne .-Ray Spectrometry 218
8. Processing of Recorded Spectrometric and Related Data 230
9. Future Trends in Airborne .-Ray Spectrometry in Uranium Exploration 234
10. Conclusions 237
References 237
Chapter 17. Borehole Logging for Uranium by Measurement of Natural .-Radiation 240
1. Introduction 240
2. Factors Influencing the Measurement of Natural .-Radiation in Borehole Logging for Uranium 242
3. Calibration 248
4. The Present State of Borehole .-Ray Logging 256
5. Conclusions 266
References 267
Chapter 18. Uranium Logging with Prompt Fission Neutrons 270
1. Introduction 270
2. Principles 270
3. Probe Description 272
4. Data Analysis 273
5. Calibration 276
6. Commercialization 276
References 277
Chapter 19. The Operation and Life of the Zetatron Neutron Tube in a Borehole Logging Application 278
1. Introduction 278
2. Tube Description 278
3. Life Experience 279
4. Application in Borehole Logging 280
5. Life Limitations 280
6. Conclusion 281
7. Summary 281
References 281
Chapter 20. Determination of the Concentration of Uranium in Soil and Stream Sediment Samples using a High Resolution Energy-dispersive x-Ray Fluorescence Analyser 282
1. Introduction 282
2. Characteristics of the Analyser 282
3. Results 286
4. Conclusions 289
References 290
Chapter 21. Uranium Isotopic Disequilibrium in Ground Water as an Indicator of Anomalies 292
1. Introduction 292
2. Uranium Geochemical Cycle and its Geochemistry 293
3. Modelling Secondary Uranium Accumulations 296
4. Modelling Uranium Isotopes in Ground Water 302
5. Case Studies of Radionuclides in Frontal Systems 307
6. Conclusions 314
References 316
Chapter 22. On-Stream Analysis of Metalliferous Ore Slurries 318
1. Introduction 318
2. Analysis Equations 319
3. Analysis Techniques 322
4. On Stream Analysis Systems 327
5. Benefits of On-stream Analysis 337
6. Future Developments 338
7. Conclusion 339
References 339
Chapter 23. Application of a Microprocessor-based Portable XRF Analyzer in Minerals Analysis 342
1. Introduction 342
2. Description 343
3. Applications 347
4. Conclusions 352
References 352
Chapter 24. Development and Application of Energy-dispersive x-ray Fluorescence Borehole Loggers and Drill Core Analysers at the Renison Tin Mine in Tasmania 354
1. Introduction 354
2. Mineralogy Found at the Renison Tin Mine 354
3. Energy-dispersive x-ray Fluorescence Analysers 355
4. Calibration of the Analysers 358
5. Applications in which the Analysers have Provided Valuable Assistance in Exploration and Mine Development Programmes at the Renison Mine 360
6. Conclusions 361
References 361
Chapter 25. A Universal Gamma–gamma Method for Simultaneous Determination of Rock and Ore Properties 362
1. Introduction 362
2. The Universal .–. Method 362
3. Experimental 364
4. Results and Discussion 365
5. Conclusions 369
References 370
Chapter 26. Fast Neutron Transport in Selected Materials Relevant to Large Volume Minerals Analysis 372
1. Introduction 372
2. Choice of Materials 374
3. Description of Neutron Flux Calculations 374
4. Analysis of Neutron Flux Distributions 375
5. Effective Source Spectra and (n,n'.) Yields 391
6. Summary 396
References 396
Chapter 27. Water Analyses in Salt Deposits Used for Radioactive Waste Depositories 398
1. Introduction 398
2. The Proposed Method 398
3. The Wet Borehole Problem 399
4. Sample Preparation 399
5. Experimental Measurements 402
6. Experimental Results 402
7. Summary 405
References 405
Chapter 28. Bulk Analysis Using Nuclear Techniques 406
1. Introduction 406
2. Determination of Iron in Iron Ore by .-Ray Backscatter 406
3. Detection of Shale in Sedimentary Iron Ores 407
4. Neutron Methods for the Analysis of Iron Ore 409
5. Determination of Alumina and Silica in Bauxite Ores 411
6. Determination of Ash and Ash Components in Coal 412
7. Determination of Manganese and Alumina in Manganese Ores 413
8. Measurement of Soil in Shredded Sugar Cane 413
9. Conclusion 414
References 414
Chapter 29. The Combination of Multi-element Neutron Activation Analysis and Multivariate Statistics for Characterisation in Geochemistry 416
1. Introduction 416
2. Mineralisation in Granite 418
3. The Identification of Diamond 420
4. The Identification of Stratigraphie Horizons in a Sedimentary Sequence 422
5. The Geochemical Characterisation of Coal Seams 423
6. Discussion and Conclusions 424
References 425
Chapter 30. The Development of a Radiometric Sorter for South African Gold Ores 426
1. Introduction 426
2. The Radiometric Sorter 426
3. Equipment Capability 428
4. Ore Characteristics 432
5. Ratio of Uranium:Gold in Individual Rock Pieces 433
6. Sampling 434
7. Machine Efficiencies 435
8. Sorting Operations 435
References 437
Chapter 31. Simultaneous Utilization of Neutrons and .-rays Ifrom 2 5 2Cf for Measurement of Moisture and Density 438
1. Introduction 438
2. Basic Consideration 439
3. Detection of Neutrons and .-Rays 440
4. Transmission Characteristics of Neutrons and .s 442
5. Development of Novel Moisture Gauge for Coke in Hoppers 443
6. Conclusion 445
References 445
Chapter 32. Mineral Exploration of the Sea bed by Towed Sea bed Spectrometers 446
1. Introduction 446
2. Natural .-Radiation 446
3. Neutron Interaction Analysis 452
4. Effect of Chlorine on Limits of Detection 458
5. Conclusions 458
References 458
Chapter 33. Tracer Techniques in Hydrology 460
1. Introduction 460
2. Environmental Isotopes and Applications 460
3. Artificial Tracers 471
4. Applications of Artificial Tracers 475
5. Conclusions 482
References 482
INDEX 486