Contents Introduction to Mine Wastes Sulfidic Mine Wastes

Transcription

1 Contents 1 Introduction to Mine Wastes Scope of the Book Definitions Mining Activities Metals, Ores and Industrial Minerals MineWastes Mine Waste Production Mine Wastes: Unwanted By-Products or Valuable Resources? Mining and Environmental Impacts ContaminationandPollution HistoricMining Present-DayUnregulatedMining Regulation of Modern Mining Rehabilitation of Mine Wastes and Mine Sites Sources of Information Summary Sulfidic Mine Wastes Introduction WeatheringofSulfidicMineWastes Acid Producing Reactions Pyrite Other Sulfides OtherMinerals AcidBufferingReactions Silicates Carbonates Exchangeable Cations ReactionRates CoalMineWastes Spontaneous Combustion of Pyritic Wastes vii

2 viii Contents 2.6 Formation and Dissolution of Secondary Minerals Pre-mining and Post-mining Secondary Minerals Solubility of Secondary Minerals Acid Consumption and Production Coatings and Hardpans Acid Generation Prediction GeologicalModeling Geological, Petrographic, Geochemical andmineralogicaldescriptions Sampling Geochemical Tests ModelingtheOxidationofSulfidicWasteDumps MonitoringSulfidicWastes Environmental Impacts Soil and Sediment Contamination PlantColonization ControlofSulfideOxidation WetCovers DryCovers Encapsulation, In-Pit Disposal and Mixing Co-disposal and Blending Addition of Organic Wastes Bactericides Summary Mine Water Introduction Sources of AMD Characterization SamplingandAnalysis Classification AcidWaters ExtremelyAcidWaters NeutraltoAlkalineWaters CoalMineWaters Processes MicrobiologicalActivity Precipitation and Dissolution of Secondary Minerals Coprecipitation AdsorptionandDesorption Eh-pHConditions HeavyMetals TheIronSystem TheAluminiumSystem TheArsenicSystem

3 Contents ix TheMercurySystem TheSulfateSystem The Carbonate System phbuffering Turbidity Prediction of Mine Water Composition GeologicalModeling Mathematical and Computational Modeling FieldIndicatorsofAMD MonitoringAMD AMDfromSulfidicWasteRockDumps HydrologyofWasteRockDumps WeatheringofWasteRockDumps Temporal Changes to Dump Seepages Environmental Impacts SurfaceWaterContamination Impact on Aquatic Life Sediment Contamination Ground Water Contamination Climate Change AMD Management Strategies TreatmentofAMD ActiveNeutralization OtherChemicalTreatments PassiveNeutralization Wetlands Bioreactors Adit Plugging Ground Water Treatment Summary Tailings Introduction TailingsCharacteristics Process Chemicals TailingsLiquids TailingsSolids TailingsDams Tailings Hydrogeology AMD Generation TailingsDamFailures Monitoring WetandDryCovers Thickened Discharge and Paste Technologies Backfilling

4 x Contents 4.6 Riverine and Lacustrine Disposal MarineDisposal RecyclingandReuse Summary Cyanidation Wastes of Gold-Silver Ores Introduction Occurrences and Uses of Cyanide Cyanide Chemistry Free Cyanide Simple Cyanide Compounds Complexed Cyanide GoldExtraction Heap Leach Process Vat/Tank Leach Process HydrometallurgicalWastes Cyanide Analysis and Monitoring Environmental Impacts Cyanide Destruction Natural Attenuation Enhanced Natural Attenuation Engineered Attentuation Summary Radioactive Wastes of Uranium Ores Introduction Mineralogy and Geochemistry of Uranium UraniumOres Placer and Beach Sands Aqueous Chemistry of Uranium OxidativeDissolutionofUraniumMinerals Uranium Solubility UraniumPrecipitation Radioactivity Principles of Radioactivity Radioactive Decay of Uranium and Thorium Units and Measurements of Radioactivity andradiationdose Radioactive Equilibrium and Disequilibrium UraniumMiningandExtraction Conventional Mining and Extraction In Situ Leach (ISL) Operations Mining,ProcessingandHydrometallurgicalWastes Tailings Tailings Radioactivity TailingsSolids

5 Contents xi TailingsLiquids TailingsDisposal Long-Term Stability of Tailings Dams MineWater Constituents Treatment Monitoring Radiation Hazards RadiationDoseandHumanHealth Occupational Radiation Exposure Environmental Impacts Excessive Radioactivity Levels and Radon Emissions Inappropriate Use of Tailings and Waste Rocks FailureofTailingsDams Soil and Sediment Contamination Ground and Surface Water Contamination Acid Mine Drainage Summary Wastes of Phosphate and Potash Ores Introduction PotashMineWastes PotashOres MiningandProcessingWastes Phosphate Mine Wastes Phosphate Rock Mining, Processing and Hydrometallurgical Wastes Phosphogypsum Disposal of Phosphogypsum Potential Hazards and Environmental Impacts Summary References Index

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