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Pre-Sizing Jig Feed Classification
Table of ContentsEqual-Settling ParticlesInterstitial Currents The extent to which sizing by sieves should be carried, as a preliminary to the separation, by jigging, of minerals of different specific gravities, has been a matter of controversy for many years. The subject has been investigated by several authorities, yet the ground does not seem to have been completely covered, nor are the
Quantitative Analysis Chemistry: GRAVIMETRIC METHODS
Table of ContentsGRAVIMETRIC METHODSPurely ChemicalSamplingSolidsSampling small ParcelsLiquidsGasesWeighing the Substance In the course of work completed, the problem so far met with has been the determination of the various elements (or compounds) present in a substance. In an ore, for instance, there may be present silica, iron, copper, arsenic, and sulphur, and it is the province of qualitative analysis to determine
Analytical Balance
Table of ContentsAnalytical Balance PrincipleAnalytical Balance Parts and FunctionThe BeamThe PansThe Standard, the Beam, and Pan ArrestmentsThe CaseThe WeightsMethods of Checking the Accuracy of the Balance & WeightsChecking the BalanceChecking the Weights of a Balance for CalibrationFirst StepSecond StepAnalytical Balance Instructions Guide Methods of WeighingDetermination of the Apparent WeightDetermination of the Absolute WeightDetermination of the Absolute WeightApparatus used in WeighingQuantity of Material to
CuSO4 Electrowinning with Crystallization
In copper SX processes, the copper extracted from the aqueous feed solution into the solvent is replaced by hydrogen ions given up by the solvent. The aqueous therefore becomes more acidic as it loses copper. To reclaim (strip) the copper from the solvent, this reaction is reversed by contacting the solvent with a more highly acidic solution. The reversible reaction
Refining of Gold Sulphide with Sulphurous Acid & Hydrogen Sulphide
Table of ContentsDrying and RoastingPulverizing and FluxingMeltingBullion and SlagLosses Method of Refining of Gold Sulphides Since the introduction of the improved method of precipitating gold from chlorine solution by SO2 and H2S at the Golden Reward chlorination-works, Deadwood, S. D., this modern method has been further adopted in the chlorination-works. It has proved practically most successful in the handling of large
Homemade DIY Laboratory Still
In the use of the apparatus purchased for the new chemical laboratories of the university, no piece has given us more satisfaction, or has been a greater success, than a new still which is the subject of this paper. In the designing of this still I had two definite objects in view ; one, the utilizing of steam from the
Train Tire Wheel Manufacturing from Ingot
Owing to certain inexplicable failures of tires, The Standard Steel Works authorized us to make a series of experiments to determine, if possible, the cause of the trouble. As a result of numerous analyses and physical tests, both from defective and experimental tires, we are able to present the following facts concerning piping and segregation, as they exist in the
Tube Muffle Furnace
The Tube Muffle Furnace is practically the common laboratory analytical gas-fired combustion-furnace, with its glass tube replaced by the iron and copper tubes, G and M, and surrounded with brick-work to lessen radiation and to give better control over the temperature. The burners, J, are those of the common combustion-furnace. The bar, K, to be heated is laid on another,
Influence of Slow Cooling From Different High Temperatures
Results of cooling steel slowly from different high temperatures are given in Tables 18, 20, 23, 24, and 25, groups VII. and VIII. In some cases (group VII.) this slow cooling was complete; in others it was interrupted by again raising the temperature, and after this the slow cooling was resumed. Bars marked T closed down without checking. When hammered
Froth Flotation: A Century of Innovation
Start following 911Metallurgy’s Linkedin page to get a free (my used) copy of: Froth Flotation: A Century of Innovation by Maurice C. Fuerstenau, Graeme J. Jameson, Roe-Hoan Yoon I will select a winner from All the Company’s Followers on February 4th 2017 and announce the winner on 911Metallurgy’s Linkedin page CLICK BELOW ON FOLLOW Contact via Linkedin will be attempted with
Steel Hardening by Quenching
Table of ContentsThe Hardening Power Apparently LagsTipper RetardationsRelation Between Carbon-Content and Rapidity of V-ChangeTime Needed For V-ChangeHardening-Power Gained at WDuctility Lost Suddenly by High-Carbon VS Low-Carbon SteelsPosition of W Probably ConstantHardening-Power Even in Hard SteelsNeutral ZoneAnalogiesExperiments on the Loss/Gain of the HardeningOSMOND’S THEORYTesting Osmond TheoryTest by Color-CarbonApparent Discrepancy Between Carbon & Ductility The Hardening Power Apparently Lags In the cooling- curves of
Heat Treatment of Steel
Table of ContentsToughening Manganese-Steel by Sudden CoolingVariations in the Rate of Cooling and in the Quenching TemperatureInfluence of Different Quenching-MediaIt Is Best to Quench from a Very High TemperatureSlightly Deferring the Immersion is Practically HarmlessSlight Retardation of Cooling Does but Slight HarmGreat Retardation of Cooling Can be ToleratedRapidity of Cooling not Imperative Below Dull RednessApplicationsCastings Should be Heated SlowlyInfluence of
Steel Quenching
Table of ContentsDifficultyInferencesLimitations of the Ductility-testsWhere is the Hardening-Power LostAgreement with Thermal Curves Loss of Hardening-Power at and near V.—We know that steel is hardened by quenching from a certain red-heat or from any higher temperature; but that if the temperature be allowed to sink below this certain point in redness, quenching will not harden the metal. In short, as
Carbon-Steel Quenching & Thermal Curves Critical Points
Table of ContentsRetardationsMode of Studying the Thermal PhenomenaNomenclatureAre V-change & W-change Reversals of Each OtherDefinitionsPredictionVerificationThe Position of the W-RangeDistribution of the RetardationsInfluence of T min on the W-retardationInfluence of T max on the V-retardationInfluence of Rate of Heating or Cooling on the RetardationsTheories of the Progress of the V-changeInertia Retardations If high-carbon tool-steel be heated to very dull redness and then
Plans How to Make a Hanging Compass
In working brown iron-ore mines on the system employed at Longdale, namely, stoping from the top down, the usual procedure is to drive a succession of upraises from the lowest adit to the highest, or to the top of the deposit, as the case may be. These upraises are usually driven 120 feet apart, along the strike of the vein.
Variable Speed Pulley
Every constructing engineer and designer knows how often it is desirable to provide a speed-adjustment between parts of a machine performing different functions, or between a prime mover and the devices to which it furnishes power, and how bulky and unsatisfactory are most of the methods by which the result is usually accomplished. Of course the step-pulley is the most
Phosphorus Determination Method
To have a complete text for a Method for the Determination of Phosphorus we must first discuss the interaction with other elements: The Effect of Arsenic.—A question involving the temperature of precipitation of ammonium phospho-molybdate, which was brought to my attention some time ago, led to the following experiment: A known quantity of arsenic was added to a steel solution,
Magnetic Ore Separator
After considerable experience in connection with the magnetic iron-ores at the South, especially in the Cranberry district of western North Carolina and eastern Tennessee, the writer was led into a thorough investigation of the magnetic separation of iron-ores, and, from this investigation, has gradually been developed a separating machine which it is the purpose of this paper to explain. Numerous
Ore Roasting & Oxidizing Furnace
This furnace is designed especially for the oxidation of sulphur or arsenic in pyritic ores, but may be used for all oxidizing or desulphurizing operations, and for calcining, roasting and chloridizing ores, or for drying ores in large quantities preparatory to treatment by magnetic separators or otherwise. It is of the tabular, revolving type, with automatic feed and delivery, and
List Minerals Containing Phosphoric Acid
The occurrence and distribution of phosphorus is one of the most important questions with which the steel-maker has to do. Large sums are invested in processes for the removal of this element from ores before they come to the blast-furnace, and much greater sums in freeing the pig-iron from it. Mechanical engineers are becoming more and more critical of the
Extraction Method of Silver Lead by Smelting
Although the subject has no practical bearing on the metallurgy of the present day, it may not be entirely uninteresting to note how the art of silver-lead smelting has been, and in a few remote districts of Peru is still practiced by an old method, and under conditions widely different from our own. The subject will be considered under the
Precipitation of Metals from Hyposulphite Solutions
Table of ContentsPREPARATION OF SODIUM & CALCIUM SULPHIDESFORMATION OF HYPOSULPHITE SALTSProducing Hyposulphites by Oxidation of Sulphide SolutionsPrecipitation of Calcium by Sodium Sulphide SolutionsRegeneration of Sodium Hyposulphite From TetrathionatePRECIPITATING COEFFICIENTSPrecipitating-Coefficients for c. p. ReagentsPrecipitation of Lead and Calcium by Na2CO3Precipitating-Coefficients far Commercial ReagentsPrecipitation of Lead and Calcium by Solvay SodaWeights of Precipitates and their Percentages in MetalsPercentages of Metals in SulphidesFinancial ResultsCost
How to Remove Fluorine from Copper Concentrates
Some copper deposits presents a small amount of fluorine associated with copper sulfide ores. Depending on the initial fluorine content and the mineralogical characteristics of the ore, the fluorine may report to the copper concentrate as an impurity. Fluorine levels of more than 200 ppm are subject to penalties in their commercialization. The presence of fluorine in copper concentrates is