Blogs
Hydrothermal Boehmite Precipitation
Table of ContentsExperimental Methods forHydrothermal Precipitation of Boehmitefrom Aluminum Chloride SolutionsHigh Temperature pH CellBoehmite Precipitation ExperimentsResults and DiscussionHigh Temperature pH MeasurementsBoehmite Precipitation ExperimentsEffect of TemperatureEffect of TimeEffect of Added HCl AcidEffect of ImpuritiesConclusions The currently proposed method for the recovery of alumina from nonbauxitic materials involves acid leaching (Figure 1). Primary emphasis is on kaolin clays. To date, leaching by
Garnet Abrasives
The mention of Garnet as a Gem is one of the very common misunderstandings about this mineral. The Garnet as a semiprecious stone does not belong in the story of Garnet, the industrial tool, and yet it shares with the diamond the double, virtue of being a thing of beauty and utility. Prior to about 1878 the Garnet was regarded
Copper Nickel Flotation
Table of ContentsRaw OrePit Ore SampleShaft Ore SampleLaboratory Copper Nickel Ore FlotationPit SampleProcedureResultsShaft SampleBatch Copper Nickel Flotation TestsCyclic Copper Nickel Flotation TestsCopper Nickel Pilot Plant FlotationPit SampleProcedureInitial ResultsComposite Concentrate ResultsTailings AnalysisSummary of ResultsShaft SampleProcedureInitial Copper Nickel Flotation ResultsComposite Concentrate ResultsSummary of Copper Nickel Flotation ResultsMaterial Balance for the Shaft Sample Flotation FlowsheetComparison of Flotation Results for Pit and Shaft SamplesSummaryConclusions The Bureau
Clay Flocculant
Table of ContentsProperties of Ethylene OxidePolyethylene Oxide as a Flocculant for ClayDescription of Clay Waste MaterialExperimentalResultsConclusions Under its mission to effect pollution abatement, the Bureau of Mines began intensified research seeking means for economically disposing of the large amounts of Florida phosphatic clay wastes and reclaiming the mined land. The clays, which are discharged from the processing plants at about
Diatomaceous Earth Filtration of Cyanide Leach Liquors in Merrill Crowe
In many instances, Diatomaceous Earth (DE) filtration could be considered a relatively recent technology. In the late 1800’s there were many references to the use of DE in small scale filtrations and in most instances these were laboratory curiosities. The use of DE in the sugar industry was proposed in the 1880’s, but this was unsuccessful for two primary reasons.
Cyanide Destruction in Gold Heap Leach
Table of ContentsHistory of the Cyanide Leach ProcessHeap CyanidationHeap NeutralizationCyanide In The Neutralized HeapFree Cyanide MeasurementWAD Cyanide MeasurementTotal Cyanide MeasurementMeasurement of Cyanide in SolidsResidual Cyanide StudiesStudy AreaMethodsSampling MethodsAnalytical MethodsResults and DiscussionCyanide and Metals Depth DistributionsCyanide and Metals Areal DistributionsPore Water BehaviorSummary and Conclusions In the past 25 years there has been a wide expansion of the use of cyanide heap
Heap Leaching Agglomeration
Table of ContentsAgglomeration ConceptWhy is Agglomeration NeededCommercial Agglomeration Heap Leaching OperationsGold Heap Leaching 20 TPDGold Vat Leaching 1500 TPDSilver Heap Leaching 2000 TPDGold Heap Leaching 2500 TPDGold Heap Leaching 3000 TPDSummary and Conclusions We investigated a particle agglomeration technique for improving the flow of leaching solution through heaps of clayey or crushed, low-grade gold-silver ores, wastes, and tailings. This technology
Ferrochromium Alloys Manufacturing
Table of ContentsEnergy Considerations for Ferrochrome Alloy ProductionSimplex ProcessPerrin ProcessSubmerged-Arc Smelting and AOD ProcessesThermodynamic Analysis of Chromia-Carbon ReactionsMaterialsExperimental Method And ApparatusCarbothermal Reduction StudiesMelting of Reduced ProductsResults and DiscussionEffect of Temperature on the ReductionEffect of Pressure on the ReductionEffect of Reactivity of Carbonaceous ReductantsEffect of Particle Size of ReactantsEvidence of Carbide IntermediariesMelting Summary and Conclusions As part of its effort to reduce
Extracting Lithium
Table of ContentsDescription of McDermitt ClaysExtraction StudiesLeach TestsWater DisaggregationHydrothermal TreatmentAcid LeachingAcid Baking Water LeachingRoast TestsAlkaline Roast Water LeachSulfate Roast Water LeachChloride Roast Water LeachMultiple Reagent Roast Water LeachPotassium Chloride-Calcium Carbonate Roast-Water LeachPotassium Chloride-Calcium Sulfate Roast-Water LeachRoast Leach Treatment SummaryRecommendations about Roast Leach Treatment The Federal Bureau of Mines investigated extraction of lithium from non-conventional resources in keeping with its goal of
Electronic Ore Sorting Copper Ore
Table of ContentsElectronic Ore Sorting MachinesBelt SorterRotary SorterOre DescriptionGeneral Geology of Michigan Native Copper DepositsOre Sample InformationPlant TestsPlant Flow Scheme and Test ProceduresGeneral Description of Ore-Processing FlowsheetTest ProceduresSampling of Test ProductsSorting Test ResultsFormal TestsDiscussionLaboratory TestsProcessing Flow Scheme & Test ProceduresOre SizingSorting FlowsheetOre Sorting Test ResultsCentennial OreKingston OreMineral Sorting Techniques This process uses electronic ore sorting or “pre-concentration” as an added
Electrolytic Reduction using Coke Electrodes
Table of ContentsExperimental ProceduresSpent EtchantsCoke Electrode CellsSmall Coke Electrode CellLarge Coke Electrode CellResults and DiscussionElectrolytic Reduction using Coke Electrodes The objective of this investigation was to reduce toxic Cr6+ in various waste processing liquors to less toxic Cr3+ while simultaneously removing copper. In addition to recovering a valuable copper product, removal of copper and reduction of Cr6+ in these liquors
Electric Arc Furnace Operation
Table of ContentsTitaniferous MaterialsLarge Scale TestsReductantsFluidizersEquipmentMelting TechniquesSmall Scale TestsTitaniferous MagnetitesLarge-Scale Open-Bath TestsSelection of MaterialsTitaniferous Magnetite OreContinuous Large Scale Submerged Arc TestsTitaniferous Magnetite OreIlmenite SandIlmenite SandDiscussion and Conclusions The lack of domestic reserves of rutile and high-grade ilmenites to accommodate the projected increased demand for TiO2 has prompted the Bureau of Mines to investigate methods for recovering titanium from lower grade
Chromic Acid Solution Electrolytic Regeneration
Table of ContentsTest ResultsPatent StatusFor More Information Etching solutions containing hexavalent chromium ions (e.g., chromic acid) are used in brass finishing, printed circuit board etching, preparation of plastic for plating, anodizing, and various other industrial surface treatment operations. As the solutions are used, hexavalent chromium ions are reduced to their trivalent state, contaminants accumulate in the solution, and the effective
Dielectric Mineral Separator
Table of ContentsDielectric Separator DesignRotating Drum Dielectric Separator OperationDesign and Operating ParametersTest ProcedureBasic Design ParametersDrum Rotation Speed & Feed RatePower ConsumptionOptimum DesignVarious Sized FractionsTwo Stage SeparationDielectric Mineral SeparationConclusions and Recommendations Dielectrophoresis, or dielectric separation, can be defined as the separation of particles according to their dielectric properties. Directly related to the dielectric properties of a particle is the particle’s dielectric
Mine Dewatering
What if the shaft were much larger, say, 300 m in diameter, or 3000 m, is the above approach to aquifer depressurization still valid? Is it feasible and practical to use wells to reduce the water inflow to a deep mine? If so, can the evaluation approach used in this paper be utilized? I believe the answers to the last
Density Separation of Materials by Using Magnetic Fluids
Table of ContentsHow Density Separation WorksTest ResultsPatent Status Continuously separate mixture of non-magnetic materials (such as scrap, precious metals, or certain ores) at a reasonable cost. Nonmagnetic materials of different densities are rapidly float/sink separated by an augmented lifting force produced in a magnetic fluid (liquid) by the effect of an external magnetic field. The magnetic fluid is a colloidal
Metallurgical Pilot Plant
The Metallurgical pilot concentration plant is completely equipped with gravity and flotation units sufficient to provide for practically any flowsheet employing these methods of concentration. All equipment for the pilot concentration plant is set for continuous operation. Due to movable launders, pumps, and flow pipes, extreme flexibility is available. Crushing: Ore is prepared in the crushing, screening, and sampling section. Grinding:
Concentrate Regrind
We used the original flowsheet for two and a half years and made concentrates containing 16%-18% insol. Then we were asked to reduce the insol content as much as possible without additional capital expenditures in an effort to improve the smelting process. One of the 7 x 10 bail mills had been outfitted with four D10B Krebs cyclones several years
Attrition Grinding Mill Design
Table of Contents Grinding of KaolinBatch Grinding StudiesSmall-Scale Continuous Grinding StudiesOpen-Circuit TestsClosed-Circuit TestsLarge-Scale Grinding StudiesOperating VariablesComminution of Industrial MineralsAttrition Grinding of MicaAttrition Grinding of PyrophylliteAttrition Grinding of TalcAttrition Grinding of MarbleBarite Attrition Grinding Grinding of Fluorite by AttritionOther Comminution StudiesGrinding MicaComminution With Nylon MediaContinuous Open Circuit Grinding TestsContinuous Closed Circuit Grinding TestsGrinding With Sand MediaAutogenous GrindingSynthetic Mica GrindingGrinding SericiteGrinding FluoriteAnthraciteLeonarditeManganese DioxideMetal PowdersGrinding AluminumGrinding CopperBeneficiating Marginal Clay DepositsBeneficiating Waste
Ferrocyanides
Table of ContentsFerrocyanides SynthesisHOW TO MAKE A FERROCYANIDECOMMERCIAL PRODUCTION of FerrocyanidesSodium FerrocyanidePotassium FerrocyanidePhysical PropertiesSODIUM FERROCYANIDECrystallographyOptical PropertiesSolubility in WaterTernary SystemsSolubility in Organic SolventsPOTASSIUM FERROCYANIDESTRUCTURE OF THE FERROCYANIDESFerrocyanide Chemical PropertiesSODIUM AND POTASSIUM FERROCYANIDESDehydrationIrradiationPyrolysisReaction with Water VaporReaction with AmmoniaOxidationReaction with AcidsReaction with MetalsReaction with Inorganic SaltsReaction with HalogensReaction with Alkylating AgentsTHE FERROCYANIDE IONOxidation and ReductionReaction with Proteins and GlucosidesHydroferrocyanic AcidFerrocyanides Usage & ApplicationsFerrocyanide Methods of
Roasting of Copper Smelter Feed
Table of ContentsExperimental WorkMaterialsExperimental ProcedureResults and DiscussionWhat happens to the Arsenic in a Static Bed Arsenic is produced in the United States as a byproduct from base metal ores. Although this production supplies only about one-half of the national demand, arsenic is generally not recovered but is treated as a troublesome impurity. Its complete recovery in domestic metallurgical plants could
Citrate Process Analytical Chemistry
Table of ContentsDescription of SamplesAnalytical MethodsSulfur SpeciesHydrogen SulfidePolysulfidesEquipment and MaterialProcedureElemental SulfurEquipment and MaterialProcedureThiosulfateEquipment and MaterialProcedurePolythionatesEquipment and MaterialProcedureDithioniteBisulfiteSulfateEquipment and MaterialProcedureBuffer SpeciesCitric AcidEquipment and MaterialProcedureGlycolic AcidEquipment and MaterialProcedureMiscellaneous SpeciesSodiumChlorideGeneral MethodsDirect-Current PolarographyEquipment and MaterialProcedureTotal SulfurEquipment and MaterialProcedureCitrate process for flue gas desulfurization One goal of the U.S. Bureau of Mines metallurgy research program is to reduce the objectionable impact of mineral-processing operations upon
Flotation of Chromite Ore
Table of ContentsEQUIPMENTFlotation of Chromite ProcedureResultsEffect of Pulp pH on Flotation of ChromiteEffect of Collectors on Flotation of Chromite OreEffect of pH Modifier Flotation of ChromitePreconditioning Acid ScrubEffect of DeslimingEffect of Ore TypeFlotation of Chromite Gravity ConcentrateConclusions The Stillwater Complex in Montana (mainly the Benbow and Mouat deposits) contains an estimated 15.7 million short tons of ore containing 1.3 million short tons of
Wet High Intensity Magnetic Separation
Table of ContentsCompare Magnetic Separation MethodsWet High-Intensity Magnetic Separation ResultsMathematical Models to Optimize Magnetic Separator DesignPractical Aspects of Effective Separator DesignBeneficiation of Oxidized Taconites WHIM is the short acronym for Wet High Intensity Magnetic Separation. At present, most U.S. iron raw materials are produced from magnetic taconites, which are ground to a nominal minus 270 mesh (53 micrometers), beneficiated by wet low-intensity