Blogs
Cellular Heap Leaching & Cyanide Regeneration
Table of ContentsCH Leaching Plant DesignLaboratory TestworkThe Cyanide Regeneration Contaminant Removal and Metal Recovery Process In conventional gold and silver heap leaching systems, crushed or uncrushed ores are generally placed in a large rectangular pile on a pad surface and sprinkled with weak cyanide leach solutions. The solutions leach the ore particles in their downward migration through, the heap. Effluent
How to Keep Bins Flowing – Safety & Material Handling
Table of ContentsBin Flow TheoriesCommon Material Flow Problems and SolutionsClassifications of Bulk MaterialsClassifying Your Own MaterialAngle of ReposeCompressibilityAngle of SpatulaUniformity CoefficientCalculating FlowabilityBin Flow AidsAir/Gravity ConveyingVibrationSonic FluidizationInternal Mechanical Flow AidsLive Bin BottomsLinersGeneral InstallationFlow Aid Accessory SuppliersBin SafetyAnd What Are Those Federal Safety Regulations?What Else Can You Do?When A Bin Must Be EnteredA New Bin Cleaning Tool Over the past several years,
Gravity Concentrators
Table of ContentsPrinciples and Methods of Gravity SeparationDesign of Gravity Separation PlantsSpiral ConcentratorsExamples of Spiral Applications For some decades now, the use of gravity separation techniques to recover valuable minerals has been relatively neglected in comparison to the developments in flotation and hydrometallurgical technology. However, more recently, there has been a resurgence of interest in gravity separation, especially in utilizing its
Gold & Silver Leaching Methods
Table of ContentsAcknowledgmentsMineralogyLeaching TechnologyHeap Leaching Ore PreparationDump Leaching Ore PreparationIn Situ Leaching Ore PreparationLeaching ProcessLeach SolutionsSolution DistributionRecoveryComparison of TechniquesZinc PrecipitationCharcoal AdsorptionLeaching OperationsArizonaCaliforniaColoradoIdahoMontanaNevadaNew MexicoSouth DakotaPermitting RegulationsFederal RegulationsState RegulationsLeaching Problems and ResearchPercolationTemperatureSolution LossCalcium Salt ScaleResearch On Novel Solution Mining MethodsIn Situ LeachingLeach FarmingThin-Layer LeachingSummary Climbing gold and silver prices during the 1970’s awakened dormant interest in mining these metals in many districts. Since
Ferric Sulfate Leaching
Table of ContentsElectrical Conductivity of Carbon/Sulfur CompositesWetting Characteristics of Elemental Sulfur Acid ferric sulfate solution has been used for heap and dump leaching of low-grade chalcopyrite ores and is being considered as a possible lixiviant for the hydrometallurgical processing of copper sulfide concentrates. For many years, researchers have attempted to explain the leaching behavior of chalcopyrite, since the reaction rate
Aluminum Extraction Method with Chloride
Table of ContentsMaterials Equipment and ProceduresResults and DiscussionEffects of Calcination Time and TemperatureSingle-Stage Leaching and CrystallizationCountercurrent Leaching and CrystallizationPurification and Solubility StudiesThermal Decomposition of ACHHDiscussion and Conclusions Almost all aluminum in the United States is produced from imported bauxite or alumina. This country has, however, more than adequate domestic nonbauxitic alumina resources that could alleviate dependency on foreign sources. For
Cordilleran Precious Metal Deposit Exploration
Since the use of potential field methods in the search for cordilleran precious metal deposits provides information on the three- dimensional locations of intrusive margins detailed potential field data would be most useful. High quality, detailed aeromagnetics and gravity information is not generally available in the initial prospecting stage, however. Regional aeromagnetics and gravity are available, but regional gravity coverage
Electrostatic Separation
Table of ContentsElectrophoresisElectrophoretic ApplicationsDielectrophoretic Applications Electrostatic separation is one of the most misunderstood physical processes used to beneficiate minerals. Nonetheless, millions of tons of titanium ores, iron ores and other minerals are processed every year economically, efficiently and safely. Over the past ten years major advances in electrostatic separation and its application have occurred. New processes include dewatering clay slurries,
Tin Electrolytic Stripping
Table of ContentsCell Design and Experimental ProcedureElectrolyte ExperimentsDetermining Electrolyte CompositionEffects of Impurities in the ElectrolyteDetinning Test ProgramResults of Detinning Postconsumer ScrapDetinning Municipal Solid Waste Magnetics Summary At present, in the United States, municipal solid waste (MSW) is generated at a rate of 3 to 5 lb/d per person. It contains about 8 pct ferrous metallics. Projections indicate -11 MMton/yr of this
How to Recover Lead from Scrap Batteries
Table of ContentsAcknowledgmentsMaterials Equipment and ProceduresBattery ScrapElectrodesSludge Leaching UnitSludge LeachingElectrolyteElectrorefining UnitElectrowinning UnitResults and DiscussionMetal RecoveryAnode and Slime BlanketCathodesSludge RecoveryLeachingElectrowinningLead MonitoringEconomic EvaluationConclusions The Bureau of Mines has investigated an electrolytic recycling process to recover lead from scrap batteries as part of the effort to improve secondary recovery of metals, minerals, and other values from waste products. This process eliminating sulfur dioxide (SO2)
How does Grinding Media Affect Galena Flotation
Sulfide ores are generally concentrated by grinding with steel media followed by flotation. Interactions between the grinding media and sulfide minerals adversely affect the floatability of the sulfides, increase the corrosive wear of the grinding media, and result in unrecovered sulfides in the flotation tailings leading to a loss of natural resources and the release of heavy metal ions in
Dump and Heap Leaching Permeability Solution
Table of ContentsPermeabilitySolution DeliverySolution Recovery The basic condition controlling the choice of a dump or heap leaching process versus a fine grinding-agitation leaching process is the grade and tonnage of the ore body. Low grade ore and small tonnages are best treated by a low-cost method such as dump or heap leaching. The permeability of the material in a dump
The Dangers of Gold Dredging
Table of ContentsLocation Mining Type and ConstructionOperational FactorsManpower FactorsCharacteristics TablesDredge Manufacturer and Consultant VisitsManufacturer VisitsConsultant VisitsMSHA Data ReviewFatal Accident SummaryNonfatal Accident SummaryLiterature Review Dredge Operation Visits The contract requirement was that nine mining dredge operations be visited to gather data on the operations, their safety hazards, and their safety management. Although the number of field trips made was the same
Dredge Safety
Table of ContentsExecutive SummaryHazards in Mining Dredge OperationsFalls into the WaterSlips and Falls on the DredgeElectrical HazardsMechanical HazardsFireHazards on ShoreOther HazardsRecommended Bureau of Mines ResearchSummary of Safety Improvement MethodsDevelopment Of Improved Personal Flotation Devices (PFD)Handbook for Dredge SafetyMaterials and Designs to Reduce Slips and FallsDredge Mining Safety ConferencesDredge Mining Research Information Office The objective of the work reported here was
How to Dissolve Galena
Table of ContentsFerric Chloride SystemEquilibrium ConsiderationsKinetic ConsiderationsExperimental Materials and ProceduresExperimental Results and DiscussionFerric Nitrate SystemExperimental Results and DiscussionKinetic ConsiderationsConclusions There has been growing concern about the adverse effects on the environment associated with high temperature processing of galena. Because of the difficulties encountered with conventional smelting, the use of hydrometallurgical techniques for lead processing has received considerable attention in the
Desliming Equipment
Table of ContentsFilter PressesAdvantages and Disadvantages of Filter PressesContinuous Pressure FiltersBelt Filter PressesAdvantages and Disadvantages of Belt Filter PressesVacuum Filtration EquipmentDrum Vacuum FiltersCake Discharge MethodsEquipment ModificationsPerformanceAdvantages and Disadvantages of Drum Vacuum FiltersRotary Disk Vacuum FiltersAdvantages and Disadvantages of Rotary Disk Vacuum FiltersHorizontal Continuous Vacuum FiltersRotary Table Vacuum FiltersHorizontal Belt Vacuum FiltersAdvantages and Disadvantages of Horizontal Vacuum FiltersSelecting and Sizing Filtration
Desliming
Table of ContentsAcknowledgmentsChemical TreatmentAdvantages and Disadvantages of Chemical TreatmentGravitational MethodsBackgroundConventional ThickenersHigh-Rate ThickenersAdvantages and Disadvantages of Conventional, and High-Rate ThickenersMultiple-Plate ThickenersTypes of Multiple-Plate ThickenersAdvantages and Disadvantages of Multiple-Plate ThickenersSizing ThickenersSettling Rate BasisSolids Flux BasisCentrifugal SedimentationBackgroundSolid-Bowl CentrifugesScreen-Bowl CentrifugesDisk CentrifugesCentrifuge PerformanceAdvantages and Disadvantages of CentrifugesSizing CentrifugesSigma ConceptPilot-Plant TestingFiltration EquipmentBackground The disposal of wet fine-grained wastes from a milling operation can be a difficult
Oxidation Reduction Effects in Depression of Sulfide Minerals
Table of ContentsOxidation of Sulfide in the Absence of Collectors or DepressantsPyriteGalenaChalcociteChalcopyriteDepression of Sulfide MineralsDepression of Cooper MineralsDepression of PyriteDepression of GalenaSummary Discussion Although a variety of inorganic and some organic reagents are used as depressants in the flotation recovery of sulfide minerals, a complete understanding of the mechanism of depressant action is still lacking. The progress in the development
Ceramic Materials are Resistant to Nitric Acid
Table of ContentsTest Equipment and Sample DescriptionAcidproof BrickAcid-Resistant Brick New mineral processing techniques being investigated by the Bureau of Mines and others, such as processing at elevated temperatures, leaching with acids and bases, chloride leaching, and dissolution in fused salt baths, may require the use of construction materials that, have good corrosion resistance. One example is the construction material needed
Grinding Ball Wear & Corrosion
Table of ContentsPitting Spalling of Grinding BallsGeneral Corrosion RegimeGalvanic Corrosion EffectsInteraction of Corrosion and Abrasion in Grinding Media Wear Wear of grinding media represents a significant cost in the wet grinding of ores in commercial ball mills. The total wear process of grinding involves a number of mechanisms including abrasive and corrosive wear. More knowledge about the wear mechanisms and
How Minor Element Affects Copper Matte Smelting
Table of ContentsArsenicAntimonyBismuthSeleniumTellurium Minor-element interactions in equilibrated samples of copper matte and silica-saturated iron silicate (fayalite) slag have been studied by the Bureau of Mines to gain basic and fundamental scientific information that will support the mineral industry’s effort to improve productivity, increase energy efficiency, and reduce undesirable environmental impacts. This work was carried out as an adjunct to a
Copper Concentrate Enrichment Process
Table of ContentsProcess ChemistryProcess Implications Most copper ore currently being mined contains copper mainly as chalcopyrite. Since chalcopyrite by itself is only about 35 percent copper, it is difficult to upgrade a concentrate by flotation to more than about 25 to 28 percent copper without losing a significant amount of copper during the cleaning steps. Some ores have associated problems
Conveyor Belt Service Machine
Design, fabricate, and test a machine capable of operating in coal seams 48-inches and thicker that can reduce the time, expense, and injury potential inherent in extending and retracting mine-wide section belt conveyors, while eliminating the need to use additional machinery or equipment in accomplishing such moves. The Problem Many underground coal mines use a belt haulage system to move
Preventing Chromium Leaching
Table of ContentsExperimental ProcedureExperimental ResultsDiscussionLeaching MethodsLeaching of Base SlagsLeaching of Altered SlagsPhase Diagram Evidence for CaO:SiO2 InfluenceOxidation of CaO·Cr2O3Selection of CaO:SiO2 Ratios for Prevention of Chromium LeachingInfluence of MgOFormation of MgO·Cr2O3Leaching and Oxidation Resistance of MgO·Cr2O3Fixing of Chromium This report presents the results of research aimed at evaluating and preventing the leaching action that may result from the disposal of