Blogs
How to Build a Clay Heap Leach Pad – Construction
Table of ContentsRequirements of Pad MaterialsDesign of Material Mixture for Clay PadConstruction of PadConstruction Quality ControlInvestigation of Pad after Leaching of First Heap Area Natural materials can be used successfully in the construction of heap leach pads. The use of these materials usually result in the least expensive approach for such facilities. Sufficient geotechnical experience has been gained in the
Concrete Crib Design
Table of ContentsDemonstrations at Sunnyside Mine No. 1Advancing Tailgate of 10 Left Longwall PanelDouble-Entry Tailgate of 17 Left Longwall PanelDemonstrations at the York Canyon Mine Double-Entry Tailgate of 8 Left Longwall PanelDemonstration 1Demonstration 2Demonstrations 3 Through 6Demonstrations 1 Through 6 SummaryAt demonstration 1At demonstration 2Demonstration 7Experimental Sections at Other MinesBethlehem steel Co., Van No. 131 MineUnited States Steel Corp., Gary
Claw Hammer Scaling Tool
Table of ContentsClaw-Hammer Scaling ToolTesting Procedures and ResultsQuality Assurance TestingPreliminary Field Testing Proper scaling is necessary for safe operation during any underground mining activity. This need is documented in the mandatory regulations for scaling found in 30 CFR 57. In many U.S. mines operating today, scaling is accomplished by manually barring-down the loose material from around the mine opening. Barring-down
Chalcopyrite Flotation without Collector – Surface Chemistry
It has been reported that chalcopyrite can be floated selectively from an ore containing pyrite, sphalerite, and silicious gangue minerals without using a collector. Sodium sulfide was used as a promoter, presumably to clean the chalcopyrite surface of its hydrophilic oxidation products. Later it was found that the potential of the pulp, measured with a platinum-calomel electrode pair, was critical
Chelating Crosslinked Starches as Flocculation
Table of ContentsExperimentalResultsDiscussionSummaryAcknowledgments One of the major technological problems associated with beneficiation of complex, finely disseminated ores is the generation of large quantities of fine minerals less than 10 µm in size. Fines are generally refractory to conventional low-cost beneficiation methods, and failure to recover this fraction can represent a significant, permanent loss of valuable minerals. In addition, fines in
Carbon Adsorption of Gold
The procedures and tests descriptions are given for the ultimate gold carbon loading tests and the dynamic gold carbon loading tests. A 4.5 parts per million gold solution was prepared by dissolving fine (-200 mesh) gold powder in a sodium cyanide solution made with deionized water at pH 10.5 (lime adjusted). This gold feed solution was fed by a metering
High Speed Vertical Screw Bulk Unloading
The Siwertell screw unloader operates at an average rate of 600 t/h with a peak capacity of over 800 t/h. The unloader consists of three screw conveyors that dig the bulk cement from the hold and deliver it to the dockside belt conveyor. The unloader will be discussed in much greater detail later in this paper. Three dust collection units
Hydraulic Mining Methods
Table of ContentsHydraulic Monitor MiningHydraulic Borehole MiningSemiautonomous Mining SystemJet Structure Studies Although hydraulic mining was introduced in the United States before the turn of the century, it has not gained the degree of acceptance found in other countries such as Russia, China, Germany and Canada. The hydraulic mining research program, which was initiated in 1958 by the Bureau of Mines
Wire Ropes & Mine Hoisting
Table of ContentsMine Safety and Health Administration Data BankData Base Management SystemResultsConclusions Although wire rope has been in use for over 100 years, it is a complex structure that is still not well understood. Wire ropes are made in diameters from less than 1/32 to more than 7 in and can have as many as 900 individual wires. The mining
Biological Leaching of Manganese Ores
Table of ContentsExperimentalOreMediaMicroorganismsChemical AnalysisShake-Flask TestsColumn TestsHeap TestResults and DiscussionPreliminary StudiesShake-Flask TestsColumn TestsHeap TestIdentification of MicroorganismsShake-Flask Tests with Other Oxide Ores Biological leaching of low-grade ores has been gaining interest and acceptability in recent years. Sulfide ores, which are subject to oxidation of specific bacteria such as Thiobacilli, are being bioleached commercially. Other ore types, especially oxides and silicates, have been
Selective In Situ Leach Mining of Manganese Ores
Table of ContentsPrevious In Situ Leach Mining Research by the Bureau of MinesPrevious Research on Manganese Ore LeachingExperimental ApproachGeochemical Characterization – Leaching ExperimentsGeologic CharacterizationDeposit CharacterizationMn RecoveryResults/Status of Bureau of Mines ResearchLeaching ExperimentsGeologic CharacterizationDeposit Characterization The Bureau of Mines is conducting research to develop cost effective, environmentally compatible advanced mining technologies for the selective extraction of critical and strategic metals. Critical
Thiol Type Collectors Adsorption Mechanisms
Table of ContentsExperimentalResults and Discussion The formation of metal xanthate can be considered to comprise an initial electrochemical reaction (E), MS → Mn+ + nS° + ne……………………………………………………………[1] followed by a chemical reaction (C), Mn+ + nX- → MXn………………………………………………………………..[2] Thus, the xanthate adsorption mechanism is controlled by both Eh and pK, and consequently, one can expect that the same may be applied to
How Unsaturated Setting Affects In Situ Copper Leaching Hydrology
Table of ContentsPhysical Property Assessment Copper Oxide OreSample and Petrographic DescriptionMoisture Retention PropertiesPressure Head and SaturationEstimating the Hydraulic PropertiesHysteresisComputer Modeling of Underground in Place LeachingMathematical Model for Unsaturated Fluid FlowFinite Element Mesh and Flow Boundary ConditionsInverse ModelingForward ModelingHydrologic DesignConclusions Hydraulic properties and characteristics of copper ore associated with the Casa Grande deposit at the Casa Grande mine are investigated by
How Froth Affects Column Flotation
The importance of the froth phase in establishing flotation performance has long been recognized. If the froth phase is insufficiently stable, mineralized bubbles which enter the froth layer rupture prematurely, causing valuable particles to drop back into the pulp. On the other hand, too stable a froth may result in nonselective entrainment of excessively large amounts of gangue particles which,
Hydrophobic Coagulation
A novel ultrafine coal cleaning process has been developed at Virginia Tech that is capable of producing superclean products. Compared to other selective aggregation processes, such as oil agglomeration and selective flocculation, this process relies on the natural hydrophobicity of the coal surface to induce the selective coagulation of coal particulates in an aqueous suspension. Since the associated mineral matter
Improve Flotation Kinetics by High Intensity Agitation
Table of ContentsIn-line Static Mixer Flotation SystemApparatusSample DescriptionExperimental ProcedureExperimental Results and DiscussionConcluding Remarks Flotation is the most widely used beneficiation technique in the minerals industry. The kinetics of flotation is governed by the rates of bubble-particle attachment and bubble-pulp separation. Both processes interact significantly in a conventional flotation unit operation, making it virtually impossible to optimize one of the processes
How to Determine Mineral Liberations by Image Analysis
Table of ContentsPredicting Grind by Analyzing Unbroken OresMineral Liberation and Optimum RecoveryDetermining the Behaviour of an Ore in a Circuit or Concentrator Evaluations of mineral beneficiation circuits and concentrators require information on mineral liberations, on mineral recoveries and on behaviours of liberated and partly liberated mineral grains. A qualitative evaluation of mineral, liberations can be made by examining polished sections
Volcanogenic Massive Sulphide Deposit
The Louvicourt deposit is proving to be a very large one. Reserves now stand at approximately 30 million tons and, more importantly, the deposit contains some impressive widths of exceptionally high grade Cu-Zn-Ag-Au mineralization that should ensure its profitability in virtually any future metal price scenario. Regional Setting The Louvicourt deposit is located approximately 15 miles east of Val d’Or,
Carbonatites Uses – Genesis and Evolution
Table of ContentsMorphology of Carbonatite ComplexesSummary of Main CharacteristicsCommodities Carbonates are a very rare and volumetrically insignificant family of igneous rocks composed mainly of carbonate minerals, and normally are described in terms of their habits (intrusive) and composition (mineralogy). No other association of igneous rocks exhibit as great a diversity of rock types and intrusive habit. They vary in shape
Geology & Mineralization – Grasberg Porphyry Copper-Gold Deposit
Table of ContentsRegional GeologyGrasbergMineralization The Grasberg copper-gold orebody is contained with a young igneous complex of dioritic composition which intrudes limestones of the Tertiary New Guinea Group. Alteration is typical of porphyry copper deposits worldwide except that higher grade primary chalcopyrite with significant gold values is associated with a centrally located zone of strong quartz stockwork. The Grasberg was
Rock Mechanics and Pit Slope Design
Table of ContentsEngineering GeologyHydrogeologyStability Analyses and Slope DesignRecommended Slope Design Kennecott Corporation, in joint venture with Galactic Resources Ltd., recently began operation of an open pit gold mining and milling facility near Columbia, South Carolina. The deposit consists of two ore bodies (North and South deposits) hosted in deformed and altered metavolcanics and metasediments of the Carolina Slate Belt. Emphasis
Mine Fan Stall – Multiple-Fan Ventilation Systems
Stall or aerodynamic stall of axial-flow fans has long been recognized as an important operational problem in mine ventilation. To develop a technique for characterizing fan stall in multiple-fan ventilation networks, a research project was initiated through the Generic Mineral Technology Center for Mine Systems Design and Ground Control. Considering that fan stall is related to multiple operating points, this
Bacterial Sulfate Reduction of Metal Contaminated Water – Treatment Process
Table of ContentsMethodsWater Sampling and AnalysisCompost Sampling and AnalysisResultsChanges in Water chemistryChanges in Compost CompositionSulfur BudgetOrigins of Effluent AlkalinityDiscussion Bacterial sulfate reduction has been identified as one process by which constructed wetland systems remove contaminant metals from coal and metal- mine drainage. Under anaerobic conditions, sulfate-reducing bacteria oxidize simple organic compounds (CH2O) with sulfate, and thereby generate hydrogen sulfide and
Commissioning Variable Speed SAG Mill Gearless Drive
Table of ContentsGeneral Description of the DriveAssembling and ConstructionComponent CharacteristicsDrive Evaluation The electric operation and design features of the 11,000 H.P. variable speed SAG mill gearless drive is presented. The function of the frequency-converter, control system drive and lubrication systems are described. An analysis of the harmonic characteristic in the Supply System and Motor is presented, and the dynamic development