Coal Preparation（选煤工程）

This book is an edited version of Felicia F. Pengs lecture notes for the course MINE 427 Coal Preparation for undergraduate mining engineering students at West Virginia University from 1997 to 2016. 
This book covers nearly all topics of operations after the coal has been brought up to the surface, from coal′s environmental effects including global warming, coals occurrence and composition and its effects on steel making and coal cleaning, various coal cleaning processes and their unit operations, to finally reclamation including black water treatment and equipment design as well as impoundment design. It comprises fourteen chapters and serves as a compilation of lecture materials spanning Professor Felicia F. Pengs teaching career. To enhance instructional effectiveness further, Chapter 14 lists seven sets of homework, five exams, and five laboratory experiments, it also offers very detailed instructions regarding objectives, safety equipments, experimental procedures, methods of data analysis, result presentations, and report formats. 
The book is specifically designed for professionals in the coal preparation industry, including coal production and related technical personnel, research and development personnel, management personnel, as well as teachers and students specializing in coal preparation.

《Coal Preparation（选煤工程）》内容是Felicia F. Peng教授1997年至2018年在西弗吉尼亚大学讲授的煤炭洗选课程教学成果的总结，全书为英文版，共十四章，以下为中文内容说明： 本书全面阐述了煤炭的环境影响(包括全球变暖)、煤炭的应用、煤炭的赋存和组成及其对洗选工艺的影响等内容。书中详细介绍了各种洗煤工艺及作业单元，包括破碎、筛分、分级、重选、浮选、脱水、干燥等工艺，几乎涵盖了煤炭被开采出地表后所经历的全部处理作业。 为了更好地方便教与学，书中第14章列出了7个家庭作业、5个考试和5个实验，对实验目的、安全设备、实验流程、数据分析方法、结果呈现和报告格式给出了非常详细的说明。可供选煤工业相关生产、技术人员、研发人员和管理人员，选煤专业相关师生学习。

1 INTRODUCTION	001
1.1　Coal Preparation is a Subsystem of Mining Operations	002
1.2　Objectives of Coal Cleaning	002
1.3　Coal Cleaning Processes	003
1.4　Coal Utilization	004
1.5　Environmental Considerations	005
1.5.1　Clean Air Act of 1990	005
1.5.2　Carbon Dioxide Emission	006
1.6　Transportation Modes of Coal	009
1.6.1　Coal Distribution Methods 	009
1.6.2　River Barge Transportation Systems	011

2 COAL	013
2.1　Formation of Coal	014
2.2　Representative Structure of Chemical Groups in Bituminous Coal	015
2.3　Parr Formula and Classification of Coal by Rank	016
2.4　Coal Resources in the United States and West Virginia	020
2.4.1　Coal Resources Distribution in the United States	020
2.4.2　Coal Resources and Coal Seams in West Virginia	021

3 COAL CHARACTERIZATION	025
3.1　Coal Sample Preparation, Analyses, and Specifications	026
3.2　Qualities of Steam and Metallurgical Coals	028
3.3　Characterization of Coal for Combustion	031
3.3.1　Proximate and Ultimate Analyses	032
3.3.2　Sulfur Forms and Analyses (ASTM D3177—89, ASTM D2492—90)	033
3.3.3　Calorific Value of Coal - Adiabatic Bomb Calorimeter (ASTM D5865—99a)	035
3.4 Hardgrove Grindability Index (HGI)	035
3.5　Mineral Matter in Coal and Ash Analysis	037
3.5.1　Mineral Matter in Coal	037
3.5.2　Fusibility of Coal Ash	039
3.6　Coal Ash Characterization	040
3.6.1　Coal Ash Slagging Potential and Deposition Indicators	041
3.6.2　Slagging Potential and Fouling Tendency of a Coal	042
3.7　Characterization of Coal for Coke	045
3.7.1　Carbonization of Coal for Coke	045
3.7.2　Fluidity or Plastic Properties of Coal by Constant-Torque Gieseler Plastometer (Audibert-Arnu Dilatometer)	045
3.7.3　Expansion and Contraction of Coal by the Sole-Heated Oven	047
3.7.4　Swelling Properties of Coal Using a Dilatometer	048
3.7.5　Free-Swelling Index (FSI)	049
3.7.6　Stability Index for Coke Using the Tumbler Test	051
3.7.7　Metallurgical Coal	051
3.8　Coal Petrography	054
3.8.1　Coal Petrographic Components	054
3.8.2　Preparation of Coal Sample for Microscopical Analysis by Reflected Light- Stopes-Heerlen System	055
3.8.3　Coal Types and Corresponding Coking Properties	056

4 COMMINUTION AND SIZE REDUCTION	059
4.1　Objective of Size Reduction 	060
4.2　Energy Requirements for Size Reduction 	060
4.3　Principle of Size Reduction and Liberation	062
4.3.1　Reduction Ratio	062
4.3.2　Specific Energy	063
4.4　Unit Operations for Comminution	065
4.5　Size Distribution Analysis	071
4.5.1　Sieve Analysis	072
4.5.2　Rosin-Rammler Equation	073

5 SCREENING, CLASSIFICATION, AND DESLIMING	077
5.1 Screen Efficiency	078
5.1.1　Efficiency of Undersize Removal	078
5.1.2　Efficiency of Undersize Recovery	080
5.2 Mass (Material) Balances	082
5.3 Crushing and Grinding Circuits	086
5.3.1　Open Circuit	087
5.3.2　Closed Circuit	088
5.3.3　Relationship between Em and Er	091
5.4　Types of Crushers Used in Mineral Processing	092
5.5　Unit Operations for Screening, Classification, and Desliming	093
5.6 Classification by Hydrocyclone	095

6 WASHABILITY ANALYSIS	097
6.1　Float-and-Sink Test	098
6.1.1　Heavy Medium Suspensions for Float-and-Sink Tests	098
6.1.2　Float-and-Sink Test Procedures	098
6.2　Washability Data Analysis	099
6.3　Composite Washability Data for Coal	106

7 GRAVITY BASED SEPARATION PROCESSES	109
7.1　Fundamental of Momentum Transport and Settling Velocity of Particles in Fluid	110
7.1.1　Criteria for Viscous Flow (Stokes Criterion for Small Particles) 	110
7.1.2　Criteria for Turbulent Flow (Newton′s Criteria for Large Particles)	112
7.1.3　Allen Equation for Intermediate Flow Region	113
7.2 Equal Settling Terminal Velocity	113
7.2.1　Free Settling	113
7.2.2　Hindered-Settling	114
7.3　Concentration Criteria	115
7.4　Separation by Difference in Settling Rate 	116
7.5　Sphericity of a Particle	117
7.6　Unit Operations for Coal Concentration	119
7.6.1　Jig	120
7.6.2　Dense Medium Vessel	125
7.6.3　Dense Medium Cyclone	125
7.6.4　Concentration Table	125
7.6.5　Water-Only Cyclone	131
7.6.6　Spiral Concentrators	133
7.6.7　Hindered-Settling Bed Separators	135
7.6.8　Pneumatic Coal Preparation Process	136

8 PROCESS EVALUATION AND PREDICTING COAL CLEANING RESULTS	141
8.1　Determination of Clean Coal Yield by Product Ash Analysis	142
8.2　Determination of Efficiency and Sharpness of Separation for a Coal Cleaning Unit	143
8.3 Prediction of Coal Cleaning Results	147

9 FROTH FLOTATION OF FINE COAL	149
9.1　Surface and Interfaces of Solid-Liquid-Gas	150
9.1.1　Young′s Equation	151
9.1.2　Dupree′s Equation	152
9.2　Effect of Coal Rank and Mineral Inclusion on Coal Floatability	152
9.3　Parameters Affecting the Rate of Flotation	153
9.3.1　Rate of Flotation in Stirred Tank Cell flotation	154
9.3.2　Pyrite Reverse Flotation Process for Desulfurization	155
9.4 Weathered Coal (Oxidized Coal)	156
9.4.1　Sources of Weathered Coal	156
9.4.2　Characteristics of Oxidized Coal	156
9.4.3　Adverse Properties of Oxidized Coal on Coal Preparation	157
9.4.4　Coal Preparation Methods of Controlling the Effects of Oxidized Coal 	157
9.5 Flotation Reagents	158
9.5.1　Effects of Non-Polar Hydrocarbon Oils 	158
9.5.2　Common Flotation Reagents Used in Fine Coal Flotation	159
9.6　Flotation Conditioner for Weathered Coal 	161
9.7　Calculation of Combustible Material Recovery	162
9.8　Unit Operations for Ultra-fine Coal 	163
9.8.1　Stirred Tank Flotation Cell	163
9.8.2　Flotation Column	165

10 DEWATERING, THICKENING, AND DRYING	167
10.1　Introduction	168
10.2　Principle of Filtration (Cake formation in filtration)	169
10.2.1　Filter Cake Resistance, Rc	170
10.2.2　Filtration Equations	171
10.2.3　Methods of Filtration Operations	172
10.3　Filtration Experiment for Determination of Filtration Area 	172
10.3.1　Constant Pressure Filtration Experiment	174
10.3.2　Estimation of Filtering Area Required for a Plate and Frame Filter Operation	175
10.4　Continuous Filtration Operations	179
10.5　Centrifugal Filtration	183
10.6　Vacuum Filters	184
10.7　Fluidized-Bed Coal Thermal Dryer	186
10.8　Flocculation and Coagulation	187
10.9　Sedimentation, Thickening, and Clarifying	190
10.9.1　Sedimentation Rate and Thickener Capacity 	190
10.9.2　Kynch Method	193
10.9.3　Operating Line	195
10.9.4　High-capacity thickening	197

11 ON-LINE COAL QUALITY MONITORING AND MATERIAL HANDLINGS	199
11.1　X1-LiNX Coal Analyzer	200
11.2 Combined Ash, Moisture and Elementary Belt Analyzer(AM-EBA) 	201
11.3　Moisture Meter	202
11.4　Elemental Analyzer	203
11.5　Belt Scale	204
11.5.1　Singe-Station Conveyor Belt Scale	204
11.5.2　Dual-Station Conveyor Belt Scale	204
11.5.3　Multi-Station Conveyor Belt Scale	205
11.6　High Speed Sorting Gate	206

12 PLANT FLOWSHEET DESIGN	207
12.1　Coal Cleaning Circuits Configuration and Plant Flowsheet Design 	208
12.2　Solids and Water Balances	215

13 COARSE REFUSE AND TAILINGS MANAGEMENT AND ENVIRONMENT	219
13.1 Tailing Dams	220
13.1.1　Methods of Tailings Dam Construction	220
13.1.2　Construction of Tailing Dam Wall Utilizing Cyclone Underflows	222
13.2　Contaminants from Reagents Used in Processed Plants 	223
13.3　Water Balance in Tailings Impoundment 	223
13.3.1　Water Gain and Loss in Impoundment	223
13.3.2　Water Reclamation System for Closed-Water Circuit	224
13.3.3　Design of a Settling Basin – An Example	225

14 HOMEWORK, PROJECTS, LABORATORY EXPERIMENTS, AND EXAMS	229
14.1 Homework	230
Homework #1 Coal Resources and Characterization 	230
Homework #2 Environmental Impact of Coal Utilization, and Crushing and Comminution 	231
Homework #3 Material Balances in Crushing Plant and Grinding Circuit	232
Homework #4 Washability Data and Prediction of Raw Coal Cleaning Results	232
Homework #5 Design Project	233
Homework #6 Flotation of Fine Coal and Oxidized Coal	234
Homework #7 Dewatering and Thickening and Online Quality Monitoring	235
14.2 Laboratory Experiments	236
Laboratory #1 - Preparation of ″representative″ Coal Sample and Chemical Analysis	236
Laboratory #2 - Size Distribution and Analysis	239
Laboratory #3 - Washability Analysis of Coal	241
Laboratory #4 - Froth Flotation	244
Laboratory #5 - Thickener Design	246
14.3 Exams	248
Exam 1 (Close books and notes)	248
Exam 2 (Close books and notes)	249
Exam 3 (Close books and notes)	251
Exam 4 (Open books)	255
Final Exam (Open book)	258

References	263

Subject Index	267