MiningOutlineWhat determines the type of mining?Depth and SizeSlide 5versusType of OreWhat are the types of mining?When do you use Surface Mining?Strip Mining of CoalOpen Pit MiningSlide 12Slide 13Some photos and machinery used in open-pit miningSlide 15?Dinky Toy?Drilling in pitCrushing in pitLoading ore in pitSlide 20When do we mine underground?Slide 22Some types of underground miningRoom and PillarCut and FillLong WallShrinkage StopingBlock CavingSolution MiningBeneficiationWhat does it entail?Slide 32Slide 33Slide 34Slide 35Refining the OreIron in reviewSulphide MineralsSulphides cont’dSmeltingResult at Kidd CreekSlide 42Slide 43Heap LeachingPotential Environmental ProblemsFrom Underground MiningSubsidence in rancher’s fieldSubsidence from Pb-Zn miningFrom UndergroundRock that has acid forming materialDrainageAcid and open pitsSlide 53Other problems with open pitsDisposal of Waste RockTailings pondsProblems with Smelting/RoastingMining Mining And its environmental impactAnd its environmental impactOutlineOutline1. Types of Mining (and why we use 1. Types of Mining (and why we use them)them)2. Beneficiation2. Beneficiation3. Smelting3. Smelting4. Environmental Concerns of 1 4. Environmental Concerns of 1 through 3through 3What determines the type of What determines the type of mining?mining?Underground v.s. Surface Mining v.s. Underground v.s. Surface Mining v.s. SolutionSolution–Depth of below surfaceDepth of below surface–Size of the ore bodySize of the ore body–Shape of the ore bodyShape of the ore body–GradeGrade–Type of OreType of OreDepth and SizeDepth and SizeShape of Ore BodyversusversusType of OreType of OreIs the ore mineral soluble in water?Is the ore mineral soluble in water?Can the ore be melted?Can the ore be melted?What are the types of What are the types of mining?mining?SurfaceSurface–StripStrip–Open PitOpen Pit–Placers--DredgingPlacers--DredgingUndergroundUndergroundSolutionSolutionWhen do you use Surface When do you use Surface Mining?Mining?Large tonnageLarge tonnageHigh rates of productionHigh rates of productionOverburden (including rock) Overburden (including rock) is thinis thinStrip Mining of CoalStrip Mining of CoalKansas Geological SurveyOpen Pit MiningOpen Pit MiningSome photos and Some photos and machinery used in open-machinery used in open-pit miningpit mining?Dinky Toy??Dinky Toy?Drilling in pitDrilling in pitCrushing in pitCrushing in pitLoading ore in pitLoading ore in pitUnderground MiningWhen do we mine When do we mine underground?underground?The ore deposit is deepThe ore deposit is deepOre body is steepOre body is steepGrade is high enough to cover costsGrade is high enough to cover costsSome types of underground Some types of underground miningminingRoom and PillarRoom and PillarCut and FillCut and FillLong wall (coal)Long wall (coal)Shrinkage StopingShrinkage StopingBlock CavingBlock CavingRoom and PillarRoom and PillarCut and FillCut and FillLong WallLong WallShrinkage StopingShrinkage StopingBlock CavingBlock Cavingwww.ivanhoe-mines.com/s/Mongolia_ImageGallerySolution MiningSolution MiningBeneficiationBeneficiationMeans of separation of ore mineral Means of separation of ore mineral from waste material (or gangue from waste material (or gangue minerals)minerals)Also known as LiberationAlso known as LiberationWhat does it entail?What does it entail?Crushing and GrindingCrushing and Grinding–Ball mill or rod millBall mill or rod millSeparationSeparation–Density (e.g. diamonds with a jig)Density (e.g. diamonds with a jig)–Magnetic propertiesMagnetic properties–Electric propertiesElectric properties–Surface propertiesSurface propertiesRefining the OreRefining the OreSmeltingSmeltingremoves the metal from the ore mineral removes the metal from the ore mineral by a variety of waysby a variety of waysHeap LeachingHeap Leaching removes metal from the ore by solutionremoves metal from the ore by solutionIron in reviewIron in reviewBlast FurnaceBlast Furnace3CO + Fe3CO + Fe22OO33 2 Fe + 3CO 2 Fe + 3CO2 (gas)2 (gas)4CO4CO ++ FeFe33OO443Fe + 4CO3Fe + 4CO2 (gas)2 (gas)Sulphide MineralsSulphide MineralsAre sometimes roastedAre sometimes roasted–Heated in air without melting to Heated in air without melting to transform sulphides to oxidestransform sulphides to oxides–Gives off HGives off H22S and SOS and SO22–Then oxides processed like Fe Then oxides processed like FeSulphides cont’dSulphides cont’dProcess of roasting and smelting Process of roasting and smelting together creates a mattetogether creates a matte–Sulfides are melted into a matte and air Sulfides are melted into a matte and air is blown through. S is converted to is blown through. S is converted to sulfur dioxide and Fe to iron oxide, and sulfur dioxide and Fe to iron oxide, and Cu and Ni stay in meltCu and Ni stay in meltSmeltingSmeltingResult at Kidd CreekResult at Kidd CreekSulphides cont’dSulphides cont’dSolvent extraction/electroplatingSolvent extraction/electroplating–Used where rock contains Cu but in too Used where rock contains Cu but in too little amounts to be recovered by little amounts to be recovered by classical methodsclassical methodsHeap LeachingHeap LeachingIn this process, typically done for Au, In this process, typically done for Au, the ore is not ground, but rather, the ore is not ground, but rather, crushed and piled on the surface. crushed and piled on the surface. Weak solutions of NaCN (0.05%) Weak solutions of NaCN (0.05%) percolate through the material percolate through the material leaching out the desired metals.leaching out the desired metals.The solutions are collected and the The solutions are collected and the metals are precipitatedmetals are precipitatedPotential Environmental Potential Environmental ProblemsProblemsA. Mining operation itselfA. Mining operation itself–Disposal of a large amount of rock and Disposal of a large amount of rock and wastewaste–NoiseNoise–DustDustBeneficiationBeneficiationSmelting and refiningSmelting and refiningFrom Underground MiningFrom Underground MiningSubsidenceSubsidence–Block/cavingBlock/caving–Room and pillarRoom and pillar–Salt mining (Droitwich)Salt mining (Droitwich)Subsidence in rancher’s Subsidence in rancher’s fieldfieldSubsidence from Pb-Zn Subsidence from Pb-Zn miningminingFrom UndergroundFrom UndergroundAcid Mine