Blogs
Effect of Sulphur in Carbon Steel
I am sure we are indebted to Prof. Hayward for his addition to our knowledge of the influence of sulphur on steel. As he has said in this paper, sulphur has had many defenders in recent years. It seems to me, however, that, while it may be old school to believe in the detrimental action of sulphur, it is not
Calculating Air Compression & Transportation Flow
Table of ContentsCompressionSpeed and AccuracyTransmissionSpeed and Accuracypv = p’v’ The four nomograms presented in this method were designed to simplify and make more, rapid the calculations connected with the compression and transmission of air. The formula involved are rather complicated, but the graphic solutions are simple; their use requires an ability to follow explicit directions and to interpolate values on a
Acid Leaching
Table of ContentsPreliminary Tests by Mr. CroasdaleAntisell ProcessProcess of Pope and HahnGreenway ProcessFinal ACID Leaching ProcessImportant ACID LEACHING Factors ExtractionAcid ConsumptionPower Consumption for ElectrolysisControl of Ferric IronSulphur ConsumptionFouling of SolutionGrade, of Copper ProducedSize of Material PercolationCirculation in the Leaching SystemCirculation in the Electrolytic SystemLead vs. Graphite AnodesControl of Ferric Iron in Acid and Neutral SolutionWashing the OreSummaryDiscussion The experimental work on the oxidized copper
Copper Leaching: 2000 TPD Plant Example
Table of ContentsLeaching Plant FeedCumulative PercentConveying and Storage EquipmentUnloading PitStorage BinsRoasting EquipmentLeaching Plant EquipmentPrecipitating DivisionDetails of OperationRoastingLeachingPrecipitatingResultsDiscussion A 2,000-ton Copper Leaching plant for the treatment of the accumulated copper concentrator tailing was built and put into operation. During the experimental period, the first step was that of laboratory experiments or beaker leaches. The results on this small scale were so satisfactory
Underground Mining Methods of Zinc Ore
Table of ContentsShaft SinkingWinding Engines and EquipmentPumping Facilities at Main ShaftsCommunication between Surface and UndergroundVentilationGeneralUnderground Development and Extraction LevelsRisesTrucksMethods of StopingOpen Stoping with BulkheadsRill StopesTransportation of FillingMain-Drive Timbering in the OrebodyTimbering of Ore ChutesPrevention of Underground FiresUnderground StaffsCods The varying physical character and large extent of the Broken Hill lode necessarily involve the employment of a variety of underground methods.
Underground Mining Methods of Copper
Table of ContentsCopper GeologyGenesis of Porphyry OreUnderground Mining-Auxiliary to Steam-Shovel OperationsShrinkage Stoping System AdoptedOrebody Worked on Three LevelsMain or Motor-Haulage LevelManway Raises and DriftsStoping OperationsUpper LevelsStope PreparationManwaysOrder of Working StopesHand Tramming on Upper LevelsGeneral CostsHammer and Piston Drills UsedWater SupplyData on Motor HaulageGravity Tram from Mine Portal to Railroad BinsSafety of Mining System The system of stoping as practiced was eminently satisfactory to supplement the
Determination Method of Melting Points of High Fusion Temperature Metals & Alloys
Table of ContentsEquipment RequiredMethod of Making DeterminationsCalibration of the Apparatus using Samples of Known Melting PointsResults Obtained with Tungsten-Molybdenum AlloysMicroscopic Examination of Tungsten and Molybdenum AlloysProbable Accuracy of ResultsCrystal System of Tungsten and Molybdenum In this paper, it is proposed to outline a method for the determination of melting points of those metals and alloys having high fusion temperatures. The
Evaluate Metal Segregation in Gold Bullion
Table of ContentsSampling MethodsVariations in AssaysConstruction of DiagramsDiscussion of Bullion Assay Curve DataSummaryDiscussion Several years ago the writer was connected with the Mint and Assay Service of the Federal Government as Assistant Assayer at the Salt Lake Assay Office. At that time cyanide bars formed approximately half of the bullion purchased by that office. Disagreement in valuation between the producer
Copper Electrolytic Refining Process Explained
Table of ContentsMineralogyGround MassIntroduced MetallicsSampling & Preparing Ore for TreatmentChemical AnalysisTreatment of OreOxidizing RoastLeaching with Dilute Sulphuric AcidElectrolytic PrecipitationElectrolytic PlantNo. 1 Step.No. 2 Step.Kinds of AnodesDepolarizing Effect of Sulphur Dioxide GasStep System of Electrolytic PrecipitationCopper Electrolysis Process ExplainedEpitome Experiments on a Porphyry Copper Ore: This research was done partly in the non-ferrous laboratory of the Department of Metallurgy of Columbia University, under the direction
Native Gold Flotation
The surfaces of native or free gold containing particles are normally hydrophobic and, if the surfaces of such particles are relatively free of contaminants they will have a tendency to float without the addition of a collector. The major sources of contamination on free gold particles are processing chemicals and small particle slime coatings. Gold tellurides also have a strong
Compressing Sample Powder to Briquet
Table of ContentsHeat Treatment of the Compressed MaterialQuartz-Tube FurnaceGran-Annular Electric FurnaceElectrical Resistance Furnace (Resistance of Charge)ForgingTemperature Measurement The mold used in producing the raw briquet is shown in Fig. 15. This consists of two halves of hardened tool steel, held together by strong bolts. Into each half is milled a polished V-shaped groove, so that when the two parts are
Tungsten & Molybdenum Alloys
Table of ContentsTungsten and MolybdenumProperties of Tungsten and MolybdenumCoaling with Precious MetalsProperties of the Coated MaterialThe Internal Structure of MetalsAmorphous Cement TheoryInfluence on Physical Properties of Gold Tungsten and Molybdenum The investigation thus far had considered, both singly and in binary combination, the entire list of available metals with the exception of tungsten and molybdenum, the treatment of which, by
Platinum Alloys with Tungsten & Molybdenum
Table of ContentsWork on Alloys made by FusionApparatusResultsPractical DeductionsExperimentsMetallographyGrinding and PolishingEtchingMicroscopyPure TungstenPure MolybdenumTungsten-Gold AlloysTungsten-Palladium AlloysTungsten-Molybdenum AlloysSummary and Conclusions Metallurgical research has discovered many an alloy possessing properties not combined in any single metal, and progress still consists chiefly in the investigation and utilization of alloys. In the case of iron, the demands of automobiles, high-speed machines and high-duty engines have led
Natural Flotation Reagents form Plants
The reagents now used in flotation consist of various acids or salts, which may be either electrolytes or nonelectrolytes, dissolved in water and some substance or combination of substances, which function as collecting or frothing agents. At times the only dissolved salts present are those naturally occurring in the water used. The general effect of the electrolyte is to greatly
Drill Holes Assay Result Interpretation
Table of ContentsNormal Conditions in Porphyry & SchistDisturbing InfluencesErratic Conditions in Porphyry & SchistRequisites for Correct InterpretationLimestone In the exploration of a copper deposit by drilling, obvious advantages are to be gained from a distinction between primary and secondary ore. Perhaps the chief of these is the aid which such a distinction renders in determining where a given hole should
Lighting Underground Mine & Illumination
In preparing this paper the object has been to set forth facts relating to lighting or illumination problems faced in underground mines, which, judging from the results realized in the iron and steel and other industries somewhat similar to mining, will tend toward furthering safety, production, and contentment of employees, as well as economy of operation in mines. By applying
Cost of Producing Concentrates from Ore
From the viewpoint of mineral economics, the ultimate and significant production cost is that per unit of metal produced rather than the cost per ton of ore treated. This viewpoint is natural to processors of ores whose final product is refined or unrefined metal, whether they be companies engaged solely in smelting, or integrated companies engaged in mining, milling, and
How & Where to Sell Ore, Concentrates, and Bullion
Table of ContentsPayments for MetalsDeductionsExample of CalculationsExample 2Domestic Dead Ores and ConcentratesPaymentsDeductionsGeneral Clauses Governing All Open SchedulesExample of Calculations With the exception of gold, metal prices are subject to frequent fluctuation, resulting in corresponding variations in the value of their ores. Metal prices are quoted periodically in technical and trade journals and average yearly prices in the principal markets are
Mining Property Engineering Valuation
Table of ContentsProperties with Large Assured Ore ReservesProperties with Little or no Assured Ore ReservesUndeveloped Properties Engineering valuations of raining properties are made for a number of purposes, principally the following: For purposes of purchase or sale on behalf of prospective buyers or vendors. For purposes of financing by bond issues or sales of stock. As a basis for taxation.
Treatment Methods of Lead & Zinc Ore
Table of ContentsLead and Zinc OresMethods of Treatment Lead and Zinc Ores Minerals of lead and zinc commonly are rather closely associated in nature; zinc-free lead ores and lead-free zinc ores are exceptional rather than common, although there are such. Lead and zinc ores usually contain some silver, but those of the Mississippi Valley region are silver-free. Indeed, lead-zinc ores
Power Electric Mining Shovel Operation
Table of ContentsPower Electric Mining Shovel & Dragline PitsEngineering Estimates Power Electric Mining Shovel & Dragline Pits The determination of mining and stripping limits prior to undertaking exploitation by power-shovel methods requires careful engineering and often involves complicated computations. Engineering Estimates Stripping of overburden and capping in open-pit mining corresponds to development work in underground mining and, as previously pointed out, is a part of the ore-production cost.
History of Mining Equipment & Practices
Table of ContentsElectric shovelsElectric locomotivesTrolley-wire system When most people think of shovels they think about the type of shovel used for metal detecting and general usage but since late in the last century, power shovels and draglines for digging and loading and locomotives and cars for hauling from the pit have been in general use at most large-scale open-pit operations.
Miner’ Safety Lamps
Table of ContentsDescription of Apparatus UsedDescription of the Miner’s LampsConditions of TestIlluminantsConclusions While electric lamps both of the cap and hand type are being introduced into many mines requiring the use of safety lamps, the oil-burning safety lamp is still used in the great majority of cases, and even where the former are used the latter must continue to be
Copper Ore Processing Methods
The four major steps in the production of marketable copper are mining, concentrating, smelting, and refining. In a few instances, however, leaching takes the place of concentrating, smelting, and refining. At present, although considerable leaching and direct-smelting ores are produced, the bulk of the copper ore mined is concentrated. The milling of copper ores as practiced in the larger concentrators