Blogs
Bulk Sample Selection & Preparation
Table of ContentsBulk SamplingCrushingQuarteringSample Pulverising or Sample Pulping Bulk Sampling The first step in assaying is to obtain a sample, and it is all important that the portion selected should be representative of the entire quantity (Fig. 1). No special pieces should be picked from the bulk, but the desired quantity is taken indiscriminately from the entire original parcel. Crushing Grind or break
Rock Crushing
Table of ContentsPortable Crushers“V” Roller CrusherRotary Jaw CrushersHammer CrushersHandling of OversizeProblems of Oversize Breakage in Portable Crusher FeedOversize Breakage in Standard Ore Handling SystemsModular AssembliesHard Rock, Low Head Room, Portable Crusher Feed System DesignHandling of Oversize An objective of the present contract is to “provide a concept for the design of a portable underground hard rock crusher in order to insure
Mining Methods VS Underground Crusher Location
Table of ContentsLow Head Room Room and PillarHigh Head Room Room and PillarLimestone MinesLead MinesOil shaleNon Room and Pillar MinesBlock CavingSublevel CavingSublevel StopingMechanized Cut & FillMinor and Combination MethodsAdvantages & Benefits of Decentralised CrushingLow Head Room Room and Pillar MinesSalt and Potash MinesWhite Pine Copper MineHigh Head Room Room and Pillar MinesDravo Lime, Maysville, KentuckyOil ShaleNon Room and Pillar MinesConclusion
Portable Rock Crushers
Table of ContentsPortable Rock Crushers in Underground MiningThe Input to the SystemOutput from the SystemPortable Rock Crusher RequirementsPrimary Crushers & Primary CrushingDefinition of the ApplicationCrusher Types and Operating CharacteristicsPressure CrushersGyratory CrushersBenefits of Gyratory CrushersJaw CrushersBenefits of Jaw CrushersHorizontal Jaw CrushersImpact CrushersCombination (Sledging ) CrushersSingle Roll Sledging CrushersFeatures of Sledging Roll CrushersFeeder BreakersLongwall BreakersComminution Without CrushingSuitability of Present CrushersCritical Input Dimension
Determining Mill Tailings Dam Seepage
Table of ContentsReview of Tailings Pond DesignSummary of the Finite-Element TheoryFinite-Element Models with Free Water SurfaceTheory of Darcian FlowIsolation of Region of StudyDarcy’s Law in Terms of Pressure and Gravitational PotentialDirectional Relationships: Theory and ApplicationLinear Pressure Variations: Basic AssumptionsContinuity EquationDetermination of Location of Free Water SurfaceApplication of the Finite-Element TechniqueNode Generation and Negative AreasUtilization of the Program Developed From the
How to Make Cupels
Make 200 good cupels, as follows: Take the box used for the purpose and fill with bone-ash, add water and mix. Use as many ounces of water as pounds of bone-ash. The right amount of water has been added when the bone-ash loses its harsh, gritty feeling, and at the same time is not pasty. A small amount of potassium carbonate
Assay Laboratory Instructions
Table of ContentsASSAYING LABORATORY REGULATIONSAssay Sample WeighingPractice in CupellationParting Gold and SilverFire Assay of Lead BullionScorificationScorification assay of silver oresScorification assay of rich gold oresScorification assay of samples containing large % of copperScorification assay fusible with difficultyScorification Assay of Silver OresQuartz-Gold Ores containing more than One-Half PyriteScorification Assay of Samples High in CopperScorification Assay of Ores Fusible with DifficultyGeneral PracticeCrucible AssaysDetermination of
Oroville Dam Construction
Thus, 2½ years after completion, the engineering feat of Oroville Dam Construction still loans large. Let us take a close look at this project to see what made it unique. To begin with, it established a number of firsts: At 770 feet it was the highest earth fill dam in the world. At $121 million dollars, it was the largest ever
Design a Dam for Mill Tailings
Table of ContentsPre-construction EngineeringSoil Sampling & Testing for Design ParametersBasic Design MethodsUpstream Method Design TechniquesDownstream MethodDams of Borrow MaterialWater-Dam ConstructionRock-Fill DamsFree-Water ControlSlope StabilityFurther Design ConsiderationsSeepage Water ControlReclamationConclusions More than ever, public opinion is demanding the design of stable embankments as part of tailings disposal systems to aid in abating air and water pollution. Even though many areas have no restrictions requiring
Grinding Mill Power
Table of ContentsGrinding Mill Power Scale-UpEffect of Lifter Height & Liner Thickness on Grinding Mill PowerEffect of Mill Lifter & Liner Wear & Shape on TonnageEffect of Pulp Rheology on Grinding Mill PowerPower Required to Drive a Rod Mill The power required to drive a tumbling mill is of interest both to the designer and to the mill operator: to the
ARSENIC IN GOLD LEACHING
What happens to arsenic during cyanidation depends what form it is in; Stibnite, orpiment, arsenopyrite, realgar. If arsenic is present, regardless of what form, solubility increases with higher pH. Environmentally; during or after detox, the arsenic can be precipitated via ferric sulphate leaching to produce the highly insoluble ferric arsenates which will settle, sometime requires the use of flocculant, in
Chalcopyrite Leaching
Leaching Chalcopyrite is the holy grail for hydrometallurgists (Leachers), difficult to leach as the sulfur forms a layer over the mineral and makes the leaching slow. Having said that, it is not 100% not leachable, not unusual for ore dumps (low grade) containing chalcopyrite to be placed under leach but report low recovery +/-30% TCu over several years and the
Electric Smelting Furnace of Ore
Table of ContentsZinc Ore SmeltingSmelting Zinc OresCopper Ore SmeltingExperience in Norway Electric Furnace Smelting PracticeSmelting Lead OresPyritic Gold & Silver Ores Containing Minor ElementsSmelting ConcentratesElectric Furnace AccessoriesElectric Furnace MetallurgyIron Ore SmeltingManganese SmeltingSmelting Chromite Electric Furnace ManufacturersWile FurnaceSmelting FurnacesConclusions and Recommendations The possibility of cheap electric power for a number of mining areas in this country has suggested to many the idea of electric smelting of nonferrous ores in small units at
Volatilization in Assaying
Table of ContentsVolatilization in CupellingLoss Through DustingCondensation of Assay Muffle FumesVapor Pressure and VolatilityVolatility of GoldVolatility of SilverRelations of Silver and OxygenVolatility of LeadFeathering as an Indication of Temperature ConditionsEffect of Other Metals on Volatilizing of Gold and SilverDetermination of Silver by CupellationDiscussion It is common to blame irregular assay results upon volatilization and much has been written upon the subject, but there is
Steel Chimney Lining of Copper Smelting Plants
Table of ContentsTile-Lined Stack for Blast and Reverberatory FurnacesBrick-Lined Blast-Furnace StackBrick-Lined Stack for Various FurnacesUnlined Stacks for Converter GasesUnlined Stacks for Blast Furnaces and ConvertersUnlined Stacks for Reverberatory FurnacesConclusion In the Southwest a number of large steel chimneys discharge the gases from the copper smelting furnaces. Some of these chimneys show no deterioration after twenty years, others show serious deterioration after four years service.
Portland Cement Composition
Table of ContentsHydration Products of Portland CementRecasting Cement AnalysesImportance of Fine GrindingLimiting Ratios of CementResults of Limiting Ratio Tests The failure, or disintegration, of concrete in structures, even when the cement, sand, and coarse aggregate used have passed satisfactorily all tests and inspections, is not uncommon. Such failures occur even when proper methods of mixing and placing have been used
Mine Haulage
The haulage system employed to convey coal from the face to the outside, dates back to 300 B. C., when slaves carried the mineral from the face to the consumer. The British discovered coal on their island about 800 A. D. and they were the first people to make practical use of coal and make coal mining a successful operation.
Zinc Roasting Furnaces
Table of ContentsRoasting Ferruginous Zinc Sulfide OresExperimental Electric Roasting FurnaceAnalytical MethodsSources and Nature of Ores TestedResults of Experimental Roasting in Electrically Heated RoasterRoasting in a Hand-Rabbled Reverberatory FurnaceRoasting in Wedge FurnacesWedge Furnace Roasting RoastingRoasting of Zinc Sulfide to Oxide & SulfateFormation of Zinc FerritesSolubility of Iron in Roasted CalcinesBehavior of ManganeseBehavior of SilicaBehavior of BasesBehavior of LeadBehavior of Arsenic and AntimonyBehavior of CopperGas
Longwall Mining
I was requested to write an article on Longwall Mining a short time ago; however, the time has been so short that I have not had time to prepare an article as I would like to have presented it to this body. In writing this article it has not been my intention in making comparison of various mines, to favor
Flotation of Pyrite
Table of ContentsDescription of SamplesPreparation of SamplesFactors Affecting Flotation of PyriteKind and Physical Condition of MineralSize of Mineral GrainsMethod of PulverizingKind and Physical Condition of GangueOil and Reagents UsedAmounts of Oils and Reagents UsedPulp DilutionPercentage of Sulfide PresentPurity of Water UsedTemperature of PulpStyle of Machine UsedMethod of TestingTests on Mountain Copper PyriteEffect of Addition AgentsEffect of Tarnish or Surface OxidationTests
Diamond Drill Sampling Methods
Table of ContentsCollecting the SludgeAveraging Core and Sludge AnalysesSplitting the CorePermanent Filing of Samples In diamond-drill work, a true sample consists of all the material cut by the bit—both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little
Mine Hoist Equipment Electrical Calculations
Table of ContentsForms used in Hoisting CalculationsCalculations for Alternating-Current Hoist MotorDrum CalculationsMaximum Rope SpeedTimeInertiaFriction of Hoist PartsLoad DiagramCapacity of Hoist MotorSpeed of MotorInput with Rheostatic ControlControl of Hoist MotorAlternating-current Hoist Motor CalculationsCalculations for a Direct-current Hoist MotorVoltage control with FlywheelCapacity of Alternating-current Induction MotorCapacity of Direct-current GeneratorDetermining the No-load Losses The rapid increase in reliability, the low cost of operation, the
Filtration of Fines & Slimes
Table of ContentsNature of SlimeFiltering RateFiltering AreaSlime CakesBuilding up Slime Filter CakesFilter Cake WashingComplete Cycle of FiltrationData from Slime Filtration PlantsConclusions The nature of slimes handled in the treatment of gold- and silver-ores has been discussed in technical literature to a considerable extent. The subject of slime-filtration from the practical worker’s standpoint has also received much comment, and scattered through the literature of
Attapulgite Ceramics
The term attapulgite and palygorskite are synonomous. Most mineralogists use the term palygorskite but attapulgite is the preferred industrial term. The structural formula of attapulgite is (OH2) (OH)2, Mg5 si8 O20 · 4H2O. The oxide composition of attapulgite is 53.64% SiO2 8.76% Al2O3, 0.60 TiO2, 3.36% Fe2O3, 0.23% FeO, 2.02% CaO, 9.05% MgO, 10.89% H2O+, 9.12% H2O, and 2.40% MnO. In