Blogs
Flotation of Rare Earths from Bastnasite Ore
Table of ContentsAcknowledgmentDescription of The SampleFlotation Equipment and ProcedurePreliminary Flotation TestsOptimization of Rougher Flotation ParametersCleaning of Rougher ConcentratesScavenging of Cleaner TailingIntegration of Rougher, Cleaner and Scavenger Flotation CircuitsFlotation of Barite from Bastnasite Rougher TailingSummary and Conclusions A large bastnasite deposit was discovered at Mountain Pass, Calif. Subsequent development of the deposit made the United States the world’s largest source of
How to Identify Scrap Metals
Table of ContentsSorting StrategyPreliminary SortingObject RecognitionColorWeightMagnet TestingSpark TestingChemical Spot TestsCombining Simple Sorting MethodsOptical Emission DevicesX-Ray Emission DevicesThermoelectric InstrumentsEddy Current TestingQuantitative Chemical AnalysisOther Potential MethodsColorimetryUltrasonic InspectionAcoustic EmissionMagnetic PermeabilityMagnetic SusceptibilityInfrared EmissionGalvanic Measurement Large quantities of scrap metals are discarded each year by industry and householders; recycling of these materials results in conservation of dwindling domestic resources and helps ease U.S. dependence on
Sand Bed Dewatering
Table of ContentsApparatusMaterialsProcedureResultsDiscussion and Conclusions In 1979, as part of its minerals environmental technology research, the Bureau of Mines began a study of mine waste tailings disposal. Part of the investigation focused on evaluating the effectiveness of the sand bed dewatering technique on alumina miniplant tailings. Alumina wastes result from the hydrochloric acid extraction of alumina from nonbauxitic ores. These
Mineral Wool Furnace Refractories
Table of ContentsRefractoriesCup TestsDescriptionDiscussion of ResultsRotary TestsDescriptionDiscussion of Results A slag formulation conforming to that used by a commercial mineral wool producer was used throughout testing. The composition of the test slag was as follows, in weight-percent: 9 copper-smelter slag, 41 lead-smelter slag, and 50 iron blast-furnace slag. Each component slag was crushed through 20 mesh, and a weighed amount
Porphyry Copper Blasting
Table of ContentsAcknowledgmentsTest SiteGeologyLaboratory Leaching TestsPhysical Properties of the Quartz Monzonite PorphyryPreblast Field OperationsTopographic MappingCore Drilling OperationsBlasting ProceduresHole Loading and Delay IntervalsBlast VibrationsBlast Damage AnalysisTopographic Mapping and Surface SwellFracture Surface MappingPostblast Drilling ProceduresLength RecoveryWeight RecoveryRock Quality DesignationSize Distribution−Drill CoreAverage SizeSize Analyses of Surface RockBlasthole Spacing DeterminationsConclusions Some are developing fragmentation technology for in situ extraction systems. An in situ extraction
Nickel Electrowinning
Table of ContentsExperimentalChannel CellEquipmentPreparation of SolutionsSynthetic ElectrolyteLeach ElectrolyteDeposit EvaluationResultsSynthetic ElectrolyteElectrochemical StudiesDeposit Evaluation5 g/l Ni²+ Electrolyte1 g/l Ni²+ ElectrolyteLeach ElectrolyteLeachingPurificationNickel Electrowinning Increasing the relative motion of the electrolyte with respect to the electrode surface has long been recognized as a means by which the mass transport of ions to the electrode can be increased to allow operation at higher current densities.
Chalcopyrite Nitrogen Roast & Leaching Electrowinning
Table of ContentsSamplesExperimental Results and Discussion RoastingHydrochloric Acid Leach To Remove IronDissolution of Copper in Oxygenated Spent ElectrolyteElectrowinning CopperRecovery of SulfurGold, Silver, and Molybdenum Present copper extraction technology is based principally on pyrometallurgical processing of sulfide concentrates in which high-temperature air-roasting and air-smelting generates large quantities of sulfur dioxide. Because of very stringent environmental standards and increasing cost of energy, there
How to Recover Mercury from Cinnabar by Electro-oxidation
Table of ContentsTheoryProcess DescriptionResults and Discussion Mercury is customarily recovered from its ores by roasting sulfide minerals and condensing the vapors to obtain the metal. The process is efficient from the standpoint of mercury removal from the calcine; however, vapor and particulate losses in the condensing system, as well as the loss owing to recombination of the mercury with sulfur,
Rock Failure Tilt Precursors
Table of ContentsExperimental ProcedureExperimental DataDiscussion A scale-invariant theory of rock failure has been proposed that predicts precursor effects prior to failure, such as anomalous VP/VS behavior and tilt, will occur in either dry or wet rock. Because the theory is scale invariant, these effects are predicted to occur on the laboratory scale over a time interval of a few milliseconds
How to Separate & Recover Molybdenum & Rhenium
Table of ContentsMaterials Equipment and ProcedureResults and DiscussionPreliminary Carbon Adsorption StudiesSolvent Extraction Studies on As-Received Elox SolutionReduction of ClO3- With SO2Molybdenum and Rhenium Extraction and Separation From Treated Process SolutionsRecovery of (NH4)6Mo7O24 From Column EffluentRecovery of NH4ReO4 From MeOH-H2O EluateRecovery of Sulfate From the Solvent Extraction RaffinatePrecious Metal Adsorption on Activated CarbonConclusions Projections for the expanded use of rhenium as
Leach Chalcopyrite using Lime Roasting Process
Table of ContentsBench-Scale Rotary Kiln TestsRoasting TemperatureParticle SizeAir FlowRoasting TimeLeachingLarge-Scale Rotary Kiln TestsLime RoastAcid LeachMolybdenum RecoveryCopper RecoveryAcid RegenerationFluidized Bed Tests Most copper is now produced from chalcopyrite flotation concentrate by smelting. While smelting achieves high recoveries of metal values at a reasonable cost, it is responsible for the discharge of large amounts of SO2 to the atmosphere. Roaster gases and,
Copper Electrowinning from Chloride Solutions
Table of ContentsExperimental EquipmentExperimental ProceduresExperimental ResultsProduct CharacteristicsConclusions The object of this research was to investigate procedures for recovering copper from chloride solutions as part of a larger program involving the application of chlorination techniques to copper and other base metal sulfide concentrates. In the first step of the process, a pelletized chalcopyrite concentrate is chlorinated in a vertical shaft countercurrent
Composition of Lead Sinter
Table of ContentsExperimental ProcedureLead SintersSintered Concentrate No AdditivesPbS-SiO2 MixturesPbS-ZnS-SiO2 MixturesPbS-CaO-SiO2PbS-CaO-ZnSPbS-ZnS-SiO2-CaOPbS-SiO2-ZnS-Fe2O3Discussion and Conclusions Blast furnace smelting of lead began over 100 years ago. The preparation of feed for the smelting operation always has been an important factor especially the elimination of sulfur by roasting. Over the years roasting progressed from heap roasting to reverberatory roasting, blast roasting in pots, and finally
Raney Nickel Alloy Melting and Casting
Table of ContentsExperimental ProcedureConclusions The conversion of coal into a high-Btu gas as a means of augmenting existing supplies of natural gas has been the subject of much research. The Bureau of Mines has played an active role in this area and has developed the Synthane process. The Synthane process consists of reacting coal, steam, and oxygen in a fluid-bed
Chalcopyrite Electrowinning Process
Table of ContentsRoast-Leach Process DescriptionExperimental ResultsOxidation RoastReduction RoastLeachingSolvent ExtractionElectrowinningSummary and ConclusionsAppendix A.- Process ChemistryRoastingLeachingSolvent Extraction and ElectrowinningAppendix B Equipment and ProceduresFluid-Bed RoastingEquipment and OperationStandard Leach Tests for Oxidized Roast ProductsStandard Leach Tests for Reduced Roast ProductsHorizontal Batch Reduction RoastEquipment and ProceduresLeachingBatch TestsContinuous TestsSolvent Extraction and ElectrowinningAppendix C Product Description and Feed PreparationChalcopyrite Flotation ConcentrateChemical Analysis and Microscopic ExaminationConcentrate Preparation for
How to Convert Stainless Steel Dust – Waste to Alloy
Table of ContentsWastesFurnace DustsMill ScaleCenterless Grinding SwarfWeighted Composite of WastesExperimental ProceduresPelletizingSmeltingReduction with CarbonReduction With Carbon Plus Scavenging With FerrosiliconTest ResultsSummaryDiscussion and Conclusions The manufacture of stainless steel results in a variety of wastes; the number, quantity, and composition are dependent on the manufacturing method used, the alloys produced, and the manner and degree of finishing of the metal products. A
Heat Capacity Enthalpies of Cuprous and Cupric Sulfides
Table of ContentsLow-Temperature Heat CapacitiesHigh-Temperature EnthalpiesStandard Enthalpies and Gibbs Energies of FormationDiscussion The present investigation of the low-temperature heat capacities and high-temperature enthalpies of synthetic cuprous sulfide and cupric sulfide is one in a series of thermodynamic studies by the Bureau of Mines on metallurgically important copper compounds. Despite the importance of cuprous and cupric sulfides in the processing of
Use Sulfuric Acid to Recover Zinc
Table of ContentsExperimental ProceduresResults and DiscussionIsothermal TestsReaction StoichiometryRate of ReactionSeparation of Reaction ProductsPurification and Electrolysis of ZnSO4 SolutionSummary This investigation was conducted by the Bureau of Mines in support of its overall goals of helping to maintain an adequate supply of minerals and metals for future national needs with minimum waste and environmental degradation. The objective of the investigation was
Water Sprays Affects Dust Suppression
Table of ContentsAcknowledgmentsProcedureResultsConclusions The Federal Coal Mine Health and Safety Act of 1969 specified that the average respirable dust level to which a miner is exposed during the work shift must be 2.0 mg/m³ or less as of January 1, 1973. In response, the Bureau of Mines initiated a program to develop new and improved methods of technology to control
How to Design Uranium Ion Exchange
Table of ContentsEquipmentSolution DescriptionExtraction Column TestsEffect of Solution Flow RateEffect of Compartment HeightEffect of Amount of Resin WithdrawalSpacing Above the Resin BedElution Column TestsSummary The Bureau of Mines has developed and tested countercurrent fluidized bed, multiple-compartment ion-exchange columns (MCIX) to recover uranium from mine water, clear solutions, and slime slurries. A 14-inch-diameter MCIX absorption column and a 4-inch-diameter fixed-bed upflow
Rock Sample Nondestructive Evaluation
Table of ContentsRadiographic PrinciplesPreliminary StudiesSpecimens and EquipmentTechnique DevelopmentExperimental Radiographic ProceduresSpecimens and AnchorsTesting ProceduresPreliminary MicrodensitometryEnhancement of Radiographic DataPhotographic MethodsDensitometric SubtractionManual MethodElectronic Method With Tandem MicrodensitometersLimestone Specimens Type “1”Shale SpecimensSandstone SpecimensLimestone Specimens Type “2”Effects of Usually Insignificant Cassette VariablesSummary of Preliminary WorkIntroduction to Advanced StudiesProduction of Multiple Sets of Standard RadiocraphsSpecimens and EquipmentRock SpecimensAnchor SpecimensEquipmentSpecimen RadiographyAnchor PositioningRadiographic ParametersAnchor BehaviorContact Prints from Radiographs
Smelting Nickel Electric Furnace
Table of ContentsSmelting Prereduced Nickel Concentrate in an Electric-Arc FurnaceMaterials Used for Smelting Tests in the Electric-Arc FurnacesEquipment and Operating Procedures for Smelting Tests in the Electric-Arc FurnacesResults of Smelting Tests in the Laboratory- and Pilot-Scale FurnacesDiscussionConclusionsAppendix.-Upgrading Ferronickel by Selective OxidationMaterialsTest Procedure and ResultsDiscussion This Bureau of Mines report results from a study on prereduced nickel concentrate from the FENI
Mine Stoppings
Table of ContentsClosing Openings with Waste MaterialsUrethane-Foam Sealed StoppingsStoppings from Concrete Blocks or WoodClosing Large Openings with Brattice ClothCost ConsiderationsConclusions Most of the mines with large openings in the United States today are salt and limestone mines. Some potash and trona mines also have moderately large openings. Moreover, it is expected that in the near future numerous underground oil shale
Iron Oxide Pigments
Table of ContentsTypes and Chemical Forms of Iron Oxide PigmentsTerminologySpecificationsManufactureProduction of Natural Iron Oxide PigmentsMines and Mining MethodsSize ReductionProduction of Synthetic Iron Oxide PigmentsThermal Decomposition (Dry Process)Solution Methods (Wet Process)Regenerator OxideAniline ProcessOperational Factors in Iron Oxide ProductionRelationships Between Iron Oxide Producers and Other Materials IndustriesEnd UsesPhysical and Chemical Characteristics of Iron Oxide PigmentsChemical and Physical StabilityParticle SizeParticle ShapeUses and ApplicationsPaintBuilding