Blogs
Countercurrent Tower Process Gold Leaching
The Kamyr countercurrent tower leach process consists of a true countercurrent leach with a flocculated ore and fibre mixture entering the top of the tower and a cyanide solution or alternative lixiviant as well as a barren wash solution entering the bottom of the tower. The Kamyr countercurrent tower leaching system has been developed for processing gold, silver and other
Lithium Spodumene Bio-Leaching
Table of ContentsPreparation of Experimental InoculumShake Flask ExperimentsTank Leaching ExperimentsBiodegradation of Spodumene by Aspergillus nigerEffect of Pulp Density on the Biodegradation of β-Spodumene A culture of niger used in this study was obtained from Professor Stoyan Groudey of Higher Institute of Mining and Geology, Sofia, Bulgaria. It was maintained on Czapex-Dox agar medium (Booth, 1971) containing 100 x 10 -6
Continuous Elution for Extraction of Gold from Carbon
The continuous elution process is a continuous counter-current system operating in a pressure vessel at elevated pressure and temperature in which both carbon and the eluate are simultaneously moving through each other in opposite directions. During this process the carbon particles enter the top of the vessel loaded with gold and exit barren through the bottom, while the hot pressurised
Hydrochloric Acid Leaching of Merrill Crowe Precipitate before Fusion – Refining Furnace
Table of ContentsLead Contamination of DoreNitre Fusion Significant copper levels were anticipated in the precipitate due to cyanide soluble species in the ore. Original design called for a hydrochloric acid leach of precipitates to remove excess zinc and copper prior to fusion. It was thought that the use of hydrochloric acid would result in low silver losses because of the
Flash Flotation of Gold
The Outokumpu flash flotation concept as an approach for precious metals recovery. Concerns were: Could a concentrate be recovered from coarse, high solids cyclone unflow. Would the proposed flash flotation machine operate on 2 continuous basis or would machine be down frequently because of plugging. Freeport was well aware of the mechanical problems with unit cells. Could flash flotation machines
Grinding Circuit Expert System Control – Artificial intelligence
Table of ContentsThe Grinding CircuitExpert System Control Strategy The clear abstraction of application specific knowledge from computer instructions is fundamental to all expert systems. This property greatly simplifies the encoding of knowledge and allows expert systems to describe their line of reasoning. Provided first that a human expert can articulate his skills, the expert system can mimic his decision making.
Prevent Permeability Loss in Heap Leaching
Table of ContentsEquipment and MaterialsPermeameterOre SamplesLeach SolutionsOrganic Cationic Polymer Clay StabilizerExperimental Procedure Results and DiscussionPermeability-Leaching TestsEffluent AnalysisClay-Swelling TestZeta Potential Measurements The Bureau of Mines Twin Cities Research Center conducts research to assist in solving problems that occur during solution mining of metals. Solution mining of uranium involves injecting a carbonate-bicarbonate (basic) or sulfate (acidic) leach solution through injection wells into
Ore Grade Control
Initial ore grade control was based on blast hole samples collected in two stages by an “automatic” sample collection device (sometimes called a rocket sampler). A sample was collected for the top 3 m (10 ft) in a holes and then the bag was changed so that a sample was collected for the lower 3 m (10 ft). Each of
Mining Truck Dispatching Method
Table of ContentsEssentials of a Truck Dispatching SystemCurrent Industry Dispatching PracticesAutomatic Truck Dispatching Algorithms The main purpose of truck dispatching systems is to increase equipment productivity. Since productivity is measured in tonnage or volume over time, productivity increases are made by decreasing truck and shovel cycle time. This decrease can be translated into more production with the existing operating equipment
Heap Leach Solution Management
Table of ContentsHeap Leach Solution Management – DecommissioningLeach and Process Solution ChemistryDecommissioning Objectives and CriteriaSolution Management OptionsFresh or Treated Water RinsingSite Water Balance and Management Plan Column testwork on run of pad ore composites has shown that varying the solution application rate from .005 gpm/ft² to .001 gpm/ft² has no effect on the overall silver or gold extraction after a
Determining Corrosion Rates in Industrial Ore Grinding Environments
Table of ContentsCorrosion Rate Determinations by Laboratory TestsElectrochemistry Of CorrosionLaboratory Test MethodsLaboratory Teat ResultsCorrosion Rate Measurements in a Copper Ore MillEquipment DesignCopper Mill Test ResultsComparison of Laboratory and Copper Ore Mill TestsAdvanced Field Test Equipment DesignAnalog-Digital ConversionRadio Transmission of DataData Reception and ProcessingCorrosion Rate Measurements in an Iron Ore MillComparison of Laboratory and Iron Ore Mill DataDiscussionConclusionsAcknowledgments Researchers at the
Tungsten & Gold Recovery Scheelite Ores
Table of ContentsSample DescriptionBig HurrahFern and IndependenceHerbert GlacierTungsten and Gold Recovery TestsGravity ConcentrationFlotationThickener Sizing TestsBatch-Settling Tests for Conventional ThickenerHigh-Rate Thickener Sizing TestsCyanide Amenability TestsCyanide ConcentrationLeaching TimeCarbon-In-Pulp Gold Adsorption TestsBatch Carbon-in-Pulp TestsContinuous Carbon-in-Pulp TestsDesign of Carbon-in-Pulp Countercurrent CascadeEquipment Design for 1,000-st/d Mill for Tungsten and Gold RecoveryConclusions Investigations were conducted by the U.S. Bureau of Mines to develop flowsheets for the
Recycle Superalloy Scrap Metals
Table of ContentsMaterialsNickel Recovery by Carbonyl FormationHigh-Temperature ChlorinationOxygen Pressure LeachingAmmonium Salt-Oxygen LeachingAcid-Oxygen LeachingChlorine-Oxygen LeachingFlowmeter-Gas ChromatographyAtomized Scrap LeachingAluminum-Chromium-Iron Precipitation From HCl-O2 Pregnant SolutionRoom-Temperature Hydroxide PrecipitationScavenger Metal-Oxygen TreatmentHydrothermal PrecipitationComparison of Scavenger Metal-Oxygen Treatment and Hydrothermal PrecipitationSolution PurificationCaustic Fusion of Oxygen Pressure-Leached ResidueChromium-Iron ReductionProposed Leaching-Purification-Electrowinning Procedure We treated mixed and contaminated superalloy scrap by pyrometallurgical and hydrometallurgical methods to separate and recover metal
Grinding Media Corrosion
Table of ContentsCorrosion Rate Determinations by Laboratory TestsElectrochemistry of CorrosionTest Materials and ProcedureTest SolutionMineral SamplesFerrous Alloy SpecimensSimulation of Abrasive ConditionsExperimental DesignDetermination and Analysis of Potential-Current DataResults and DiscussionChalcopyriteEffect on Corrosion RatesElectrochemical ReactionsGalenaEffect on Corrosion RatesSynergistic Effects of Galena, Oxygen, and pH on Corrosion of Carbon SteelSphaleriteEffect on Corrosion RatesElectrochemical Reactions We determined the effect of common sulfide minerals on the
Natural Flake Graphite & Carbon Fiber VS Dolomite-Carbon Refractories
Table of ContentsRaw Materials and Sample DescriptionTest Equipment and ProcedureResults and DiscussionBulk Density and Retained CarbonMorThermal Expansion under LoadAir-Slag-Metal WearConclusions We investigated the role of imported natural flake graphites in dolomite-carbon refractories used in steelmaking processes and evaluated carbon fibers as a potential substitute. Varying quantities (1.5-30 pct) of natural flake graphite and carbon fibers were added to test samples.
How Metal Impurities Affect Gold Adsorption on Activated Carbon in Cyanide Solutions
Table of ContentsPreparation of Activated CarbonPreparation of Contact SolutionsContact Test ProcedureResults and DiscussionEffect of pH on Metal Cyanide Complex LoadingEffect of Metal Cyanide Complexes on Gold LoadingEffect of Gold on Metal Cyanide Complex Loading We performed batch equilibrium contact experiments to examine the ability of activated coconut-shell carbon to adsorb various metal cyanide complexes. Tests were also conducted to determine
Procedure to Determine Helium in Water
Table of ContentsApparatus DescriptionSample CollectionGas Extraction and Addition of Diluent GasExtracted-Gas AnalysisCalibrationCalculationsDiscussion of ResultsCalibration CurveDetermination of Helium-Extraction EfficiencyPrecision of Ground-Water AnalysisAccuracy of Ground-Water AnalysisSecond MethodApparatus DescriptionProceduresSample CollectionIntroduction of Internal Standard and Gas ExtractionAnalysis of the Extracted GasDetermination of the Helium-to-Neon-21 Sensitivity RatioCalculationsDiscussion of ResultsHelium-to-Neon-21 Sensitivity Ratio DeterminationEquilibration StudyLoss of Helium During SamplingPrecision of Ground Water AnalysisAccuracy of the Analytical Method
Tailings Backfill
Table of ContentsMix CompositionMix HandlingLaboratory TestingTest AnalysisLaboratory TestsStatistical AnalysisDiscussion of Results This report presents a study of three typical tailings samples as potential cemented backfill in underground mines. The testing series was unique in that the pulp densities of the samples were all above 75 pct solids. Test results included dry density; slump; percent settling after 28 days of curing;
Conveyor Belt Cleaning Systems
Table of ContentsTest FacilityInvestigation Results Objective Reduce the number of conveyor-related accidents in the mining industry by providing recommendations for effective operation of conveyor belt cleaning systems. The Problem Troughed belt conveyors provide effective and efficient materials transport and their use has increased throughout the mining industry. Carryback, the spillage that accumulates under the belt, is a problem even with
Water-Jet Rock Drilling
Table of ContentsCollimatorJet Deflectors for Cutting ClearanceNonpressurized Swivel for Passing Abrasive StreamsDesign of the DrillDrillingAbrasivesParametric Drilling Studies on Nickel Ore Water PressureDrill Fluid ChemistryDrill Rotation SpeedPipe SizePolyethylene Oxide AdditiveKerfing Abstract The U.S. Bureau of Mines has patented and transferred to industry an abrasive-enhanced water-jet rock drill. This drill incorporates three novel components: a collimator, jet deflectors for cutting clearance, and an
Turbo Milling & Ultrafine High-Purity Ceramic Powders
Table of ContentsHow It WorksTest ResultsFor More Information Objective Utilize innovative processing technology to prepare high-purity, ultrafine advanced ceramic powders with little or no contamination occurring during the milling proccss. Advanced ceramic materials made from these powders could substitute for high-temperature alloys containing critical materials such as chromium, cobalt, and nickel. Approach Modify and evaluate the Bureau’s turbomill, developed earlier
In Situ Copper Leach Mine Design Procedure
Table of ContentsAbout In Situ Leach Mining for CopperDesign Procedures Objective Provide the U.S. mining industry with technology for designing environmentally sound, low- cost in situ leach mining operations to produce copper from small, deep, and/or low-grade copper oxide deposits. Approach Investigate the feasibility of a new mining method-in situ leach mining-as an alternative to conventional mining for copper. Study
How to Make Lead from Galena Concentrates
Table of ContentsHow It WorksTest Results Objective Provide an environmentally compatible means of producing lead from galena concentrates that replaces the current high-temperature pyrometallurgical primary lead smelting process and supplies pure lead metal within present and proposed Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) lead emission standards. Approach The U.S. Bureau of Mines developed an energy
Zeta Potential
Table of ContentsZeta Potential Test EquipmentZeta Potential Test ProcedureZero Surface Charge Concentration DeterminationEffect of Water Quality on PZC ConcentrationEffect of Material Composition on PZC ConcentrationEffect of Inorganic Salt Cation Valence on PZC ConcentrationEffect of Anionic and Nonionic Additives on Zeta PotentialEffect of Anionic Plus Nonionic Combinations on Zeta PotentialEffect of Excess Cationic Additive on Zeta Potential A novel technique has