Industrial Water - Quality Requirements

Front Matter......Page 1
Part V. Instrumentation, Modeling, and Simulation......Page 0
Preface......Page 3
Table of Contents......Page 4
1.1 Introduction......Page 7
1.2.1 Specific Throughput......Page 9
1.2.2 Variation in Throughput with Key Variables......Page 10
1.2.3 Specific Pressing Force......Page 11
1.3 Simulation of HPGR Performance......Page 12
1.3.2 Application of Piston Press to Provide Conceptual-Level HPGR Performance Estimates......Page 14
1.4 Conclusions......Page 16
Acknowledgments......Page 17
References......Page 18
2.1 Introduction......Page 19
2.2.2 Technology Motivators......Page 20
2.2.3 Technology Status......Page 22
2.4 The Manufacturers and Their Designs......Page 24
2.5 Operating Characteristics......Page 27
2.5.3 Specific Energy Input......Page 28
2.5.5 Feed Top Size......Page 29
2.5.8 Circuit Capacity......Page 30
2.5.9 Product Sizing......Page 31
2.5.10 Roll Surface Wear......Page 32
2.5.11 Tramp Steel......Page 33
2.6 Flowsheet Options......Page 34
2.6.2 SAG Mill Pebble Crushing......Page 35
2.6.4 Open-Circuit HPGR with Edge Recycle......Page 36
2.7 Analysis of Technology Benefits......Page 37
2.8 Comparison with Conventional Technologies......Page 39
2.10 Conclusion......Page 40
Bibliography......Page 41
3.1 The Very Basics......Page 44
3.1.1 The Principle of High-Pressure Grinding......Page 45
3.1.2 Some Formulas......Page 46
3.2 The HPGR Bonus......Page 47
3.2.2 HPGR Applications in Mining......Page 48
3.3 Conclusions......Page 49
4.1 Introduction......Page 53
4.2.2 Newmont Gold, Lone Tree (Nevada)......Page 54
4.4 Optimum HPGR Performance in Closed-Circuit Operation......Page 56
4.5 Ball Mill Energy Requirements......Page 61
4.6 ORE Characterisation for HPGR Treatment......Page 64
4.6.2 Polycom Abrasion Index......Page 66
4.6.3 Ore Categorisation......Page 67
4.7 Conclusions......Page 68
Bibliography......Page 69
5.1 Introduction......Page 70
5.2 The Selection of Mills - Equipment Options......Page 71
5.2.2 Pin Mill......Page 72
5.2.6 Jet Mill or Fluid Energy Mill......Page 73
5.3.1 Defining Product Size......Page 74
5.3.2 Particle-Size Measurement......Page 75
5.4 Determination of the Specific Energy Required......Page 77
5.4.1 Media Considerations......Page 78
5.4.1.2 Media Type......Page 79
5.4.1.4 Media Hardness......Page 81
5.4.1.5 Operating Parameters......Page 82
5.5.2 Number of Mills......Page 83
5.6.1 Ziniflex Century Ultrafine Milling Circuit......Page 85
References......Page 86
6.1 Introduction......Page 87
6.2 Experimental Procedures......Page 88
6.3.1 Monosized Grinding Beads......Page 89
6.3.2 Bead-Size Distribution......Page 93
6.4 Conclusions......Page 96
References......Page 97
7.1 Introduction......Page 99
7.2 Model of Stressing Particles in a Mill......Page 100
7.3 Relation between Specific Energy, Stress Energy, and Stress Number......Page 103
7.4 Application of the Stress Model......Page 104
7.5 Determination of Power Draw......Page 107
7.6 Determination of Production Rate......Page 111
7.7 Conclusions......Page 113
References......Page 114
8.1 Introduction......Page 115
8.3 Analysis of AG/SAG Circuit Energy Efficiency Using Bond\'s Equation......Page 116
8.4 Efficiency of AG/SAG and Ball Mill Circuits......Page 118
8.5 New Approach to Predicting AG/SAG Specific Energy......Page 121
8.6 SMC Test Description......Page 122
8.7.1 AG and SAG Mill Circuits......Page 124
8.7.2 Mine-to-Mill Applications......Page 125
8.7.3 High-Pressure Grinding Rolls......Page 126
Bibliography......Page 127
9.1 Introduction......Page 130
9.1.1 Coarse Inflections......Page 132
9.1.2 Fine Inflections......Page 133
9.2 Plant Sampling Studies......Page 136
9.2.2 Discussion - Plant Sampling......Page 137
9.3.1 Equipment......Page 139
9.3.2.2 Experiments with Magnetite/Quartz Mixtures......Page 140
9.3.3.2 Mineral Mixture Results......Page 142
9.4 Conclusions......Page 145
References......Page 146
10.1 Introduction......Page 147
10.2.1 Plant Sampling and Sample Analysis......Page 148
10.2.2 Mass Balancing and Performance Evaluation......Page 149
10.2.2.1 Identifying Bottlenecks......Page 150
10.2.3 Alternatives for Improved Performance......Page 151
10.2.4 Modeling and Plant Simulation......Page 152
10.2.5 Results of Simulations, Selection of Most-Feasible Alternatives, and Plant Implementation......Page 154
10.2.6 Validation of Simulation Results......Page 155
10.4 Future Plans......Page 156
10.5 Conclusion......Page 157
References......Page 158
11.2 Problem......Page 159
11.3 Background to the Current Work......Page 160
11.5 SAG Mill Modeling......Page 161
11.6.1 Reduced Number of Inputs......Page 163
11.7 Discussions......Page 164
11.8 Conclusions......Page 165
References......Page 166
12.1 Introduction......Page 167
12.2.1 Tube Ball Mill......Page 168
12.2.2 Vertical Roller Mill......Page 169
12.2.3 Horizontal Roller Mill......Page 170
12.2.5 Air Classifier......Page 171
12.3 Circuit Configuration for Improved Energy Efficiency......Page 173
Bibliography......Page 176
13.1 Introduction......Page 178
13.2 Results for Pattern Recognition in SAG Mill Operation......Page 179
13.2.2 SAG Mill Variability Patterns (Worn Liners)......Page 182
13.2.3 Example: Iron Content in SAG Mill Feed......Page 183
13.2.4 Example: Effect of Stockpile Level......Page 185
13.4 Conclusions......Page 186
Bibliography......Page 187
14.1.1 Operation of SAG Mills......Page 189
14.1.1.2 Flow through the Grate and Pulp Lifters......Page 190
14.1.2.1 MillSoft - Discrete Element Simulation of SAG Mills......Page 191
14.1.2.2 Shell Lifter Design and Charge Motion Analysis with MillSoft......Page 192
14.1.3.1 Grate and Pulp Lifters......Page 193
14.1.3.3 Shell-Lifter Redesign......Page 194
14.1.3.5 Impact on Power Draw and Energy Consumption......Page 196
Acknowledgments......Page 198
Bibliography......Page 199
15.1 Introduction......Page 201
15.2 Idealized Stress Distributions and Fracture Mechanics in Impacted Spheres......Page 202
15.3 A More Realistic Picture of the Impact Breakage of Nonspherical Particles......Page 204
15.4 The Orientation Effect in Repeated Impacts......Page 207
15.5 Impact Tests and the King-Tavares Test......Page 208
15.6 Experimental Results......Page 212
15.7 Fragment Distributions......Page 213
15.8 Conclusions and Future Work......Page 214
References......Page 215
Appendix A: Hertzian Solutions for Impact of Spheres......Page 217
Appendix B: Allowance for Energy Utilization Factors......Page 219
16.1.1 A Visualization of Mineral Liberation due to Size Reduction......Page 220
16.2.1.1 The Fully Liberated Minerals......Page 221
16.2.1.2 Comparison of the Model with Reality - Magnetic Iron Formations......Page 222
16.2.2 Expansion of the Gaudin Random Liberation Model......Page 223
16.2.2.2 Quantifying Locked Particles......Page 225
16.2.2.3 One Approach to Solving the Distribution Problem for Locked Particle Breakage......Page 226
16.2.2.4 Incorporation into a Size Reduction/Mineral Liberation Simulation Program......Page 228
16.3.1 Expanding the Number of Composition Ranges......Page 231
16.3.2 Solitary Grain Model Representation of a Low-Grade Ore......Page 232
16.4 Summary and Conclusions......Page 234
References......Page 235
17.1 Introduction......Page 237
17.2.1 Materials......Page 238
17.2.2.3 Viscometer......Page 240
17.2.2.5 Specific Surface Area......Page 241
17.3.1 Effect of Molecular Weight of a Dispersant......Page 242
17.3.2 Effect of Solids Concentration......Page 246
17.4 Conclusions......Page 251
References......Page 252
18.1 Introduction......Page 255
18.2 Theory......Page 256
18.4 Results and Discussion......Page 257
References......Page 262
19.1 Introduction......Page 263
19.2 Pilot-Mill Experimental Work and Results......Page 264
19.3 Modeling Approach......Page 266
19.5 Prediction of Rock Wear Rates......Page 268
19.6 Discussion of DEM Predictions of Detailed Charge Motion......Page 272
19.7 Conclusions......Page 276
References......Page 277
20.2 Experimental Materials and Methods......Page 278
20.3 Results and Discussion......Page 280
20.4 Conclusions......Page 283
References......Page 284
21.2 Lab-Scale Experiments......Page 286
21.3 Modeling of the Grinding Attrition Microprocess......Page 287
21.5 Stress Number......Page 292
21.5.1 Specific Energy Input......Page 295
21.6 Model Validation......Page 297
21.7 Conclusions......Page 298
References......Page 299
22.1 Introduction......Page 301
22.2 Plant Sampling Studies......Page 302
22.3.1 Base Circuit Simulations......Page 304
22.3.2 Modified Circuit Simulations......Page 306
References......Page 311
23.1 Introduction......Page 313
23.2.3.2 Vortex Finder and Spigot Sizes......Page 314
23.2.3.3 Hydrocyclone Pressure......Page 315
23.2.4 Analysis Procedures......Page 316
23.3.1 Quality of Separation......Page 317
23.3.3 Mass Recovery to Underflow......Page 318
23.3.5 Hydrocyclone Throughput/Flow Rate......Page 320
References......Page 322
24.1 Introduction......Page 323
24.2.1 Design and Structure......Page 324
24.2.2 Materials......Page 327
24.2.3 Rubber Liners......Page 328
24.2.4 Magnetic Liners......Page 329
24.3.2 Bad Examples......Page 331
24.4.1 Noisy Mill......Page 333
24.4.3 Excessive Liner Wear......Page 334
24.5 Pilot Tests of the Influence of Liner Design......Page 335
24.6.1 Near-Field-Condition Testing......Page 336
24.6.2.1 Background......Page 337
24.6.2.2 Abrasion Test Development......Page 338
24.6.2.3 Future Directions......Page 339
24.7 Influence of Lifter Bar Height on Liner Life......Page 340
24.8 Optimising Liner Design......Page 341
24.9 Utilising Outer Charge Trajectories to Design Liner Profiles......Page 342
24.9.1 Utilising Charge Trajectory Predictions......Page 343
24.9.1.4 Mill Drilling......Page 344
24.9.1.5 Mill Speed......Page 345
24.9.1.7 Mill Control......Page 346
24.9.2 Summary of Optimising Liner Design......Page 347
24.10 Full Charge Trajectories - DEM Modeling......Page 348
24.10.1 Charge Motion......Page 349
24.10.3 Liner Wear Distributions......Page 350
24.10.4 Effect of Liner Height on Abrasive Wear......Page 353
24.11.1 Liner Wear Measurement......Page 355
24.11.2 Mill Liner Inspections......Page 357
24.12 Liner Design Detailing......Page 358
24.13.1 Feed Preparation......Page 359
24.13.3 Load Calibration......Page 360
24.13.4 Using a Power Model......Page 362
24.13.6 Ball Mill Steel Load......Page 363
24.15 Conclusions......Page 364
Bibliography......Page 365
25.1 Introduction......Page 369
25.2 Background......Page 370
25.3 Analysis and Results......Page 371
25.4 Current Situation at the Mine......Page 373
Acknowledgments......Page 374
References......Page 375
26.1 Introduction......Page 376
26.2 Particle-Size Distributions......Page 377
26.3 Determining Grinding Power Using Bond\'s Equation......Page 379
26.5.1.2 EF2 - Open-Circuit Grinding......Page 380
26.5.1.4 EF4 - Oversized Feed......Page 381
26.5.1.8 EF8 - Rod Milling......Page 382
26.6 Single-Stage Ball Mill Circuit Example......Page 383
26.8 Ball Mill Size Scale-up......Page 384
References......Page 387
27.2.1 Current Experience - Wide-Space and Large-Angle Shell Lifters......Page 389
27.2.2 Shell Liner Design and Mill Performance......Page 390
27.2.3 Mill Charge Levels......Page 393
27.3.1 End Liner Design/Life Issues......Page 396
27.5 Liner Size and Materials......Page 397
References......Page 399
28.1 Basic Data and Physical Layout......Page 402
28.2 The History of the Gearless Mill Drive......Page 403
28.3.1 Rotor Installation......Page 404
28.3.3 Stator Design......Page 406
28.3.5 Stator Installation......Page 408
28.3.6 Sealing System......Page 410
28.3.9 The Secondary Cooling Circuit......Page 412
28.3.11 Water-to-Air Heat Exchanger......Page 413
28.3.12 Air-Gap Monitoring......Page 414
28.3.14 Physical Arrangement......Page 415
28.4 The House......Page 416
28.4.1.2 Methods of Controlling the Cycloconverter/Motor......Page 417
28.5.2 Inrush Current Effects of Switching on the Converter Transformers......Page 419
28.6.1 GMD Starting Characteristic......Page 421
28.7 Design Conditions......Page 422
28.9 Conclusions......Page 423
29.2 Control Concept......Page 424
29.3 Hydrocyclone Operation at the Transition Point Rope/Spray Discharge......Page 426
29.6 Solids Content and Solids Recovery......Page 427
29.7 Optimization Criterion......Page 428
References......Page 432
30.1 Introduction......Page 434
30.2 Fundamentals of High-Fidelity Simulation Tools......Page 436
30.3 Recent Applications of the HFS to Comminution System Optimization......Page 438
30.3.1 Optimizing Crushers......Page 439
30.4 Optimizing SAG and Ball Mills......Page 440
30.6 Conclusions......Page 444
Acknowledgments......Page 445
References......Page 446
31.1 Introduction......Page 448
31.4 New Technique for Ore Domain Definition......Page 449
31.4.2 Ore Hardness......Page 450
31.4.3 Ore Domain Definition......Page 452
31.4.4 Ore Hardness with 16 Domains......Page 453
31.5 Mill Throughput Models......Page 454
31.5.1.2 Bond Work Index Modeling (2002)......Page 455
31.5.1.5 JKSimMet Modeling (late 2003)......Page 456
31.6 Integrated Mill Throughput Modeling......Page 457
31.6.2 Predicting Mill Throughput for Varied Blast Designs......Page 459
31.7 Application of the Model......Page 461
31.8 Continuous Throughput Model......Page 463
31.9 Future Model Refinements......Page 464
Bibliography......Page 465
32.1 Introduction......Page 467
32.2.1.1 Description of Feed Material......Page 468
32.2.1.2 Flowsheet......Page 469
32.2.2 Validation against Full-Scale Circuit......Page 471
32.2.3 Comparison with Traditional Scaling Procedures......Page 473
32.3.1 Process Model Description......Page 475
32.3.2 Simulation of Process Upsets......Page 476
References......Page 479
33.1 Introduction......Page 480
33.2 Size-Reduction Modeling......Page 481
33.2.2 Size Reduction......Page 482
33.2.4 Breakage Matrix......Page 483
33.2.5 Selection Function......Page 484
33.2.7 Available Energy......Page 485
33.2.8 Residence-Time Distribution......Page 486
33.3 Size Classification Modeling......Page 487
33.4 Phase Modeling......Page 488
33.4.1 Size Distribution......Page 489
33.4.4 Mineral Liberation Data......Page 490
33.4.5 The Gaudin Random Liberation Model......Page 491
33.5 Flowsheet Simulation......Page 493
References......Page 495
34.2 Ray Mines Example......Page 497
34.4 Phenomenological Modeling - Population Balance Models......Page 498
34.6 Crisp Rules......Page 501
34.7 Fuzzy Logic......Page 502
34.8 Neural Network Models......Page 503
34.9 Modern Expert Control of a Large Grinding Circuit......Page 506
34.10 Industry Challenges - Three Problems......Page 507
34.12 The Near-Term Future - Long-Range Distributed Control......Page 508
Bibliography......Page 509
35.1 Introduction......Page 511
35.2.1.1 Power......Page 512
35.2.1.2 Particle-Size Distribution......Page 513
35.2.2.2 Force Sensor......Page 514
35.2.2.3 Vibration Sensor......Page 517
35.3 Vibration Analysis of a SAG Mill - A Case Study......Page 518
35.4 Discussion......Page 521
References......Page 522
36.2 Work Index Analysis......Page 523
36.3 Population Balance Computer Modeling......Page 524
36.4 The Functional Performance Equation......Page 525
36.6 Example Case Studies......Page 526
References......Page 529
B......Page 531
C......Page 534
D......Page 535
E......Page 536
G......Page 537
H......Page 540
L......Page 544
M......Page 545
N......Page 551
O......Page 552
P......Page 553
R......Page 554
S......Page 555
V......Page 564
W......Page 565