Blogs
Screen Scale for Testing Sieves
Since the adoption by the U. S. Bureau of Standards several years ago of specifications for standard 100- and 200-mesh sieves, frequent requests have been received that this Bureau test and certify sieves of other sizes than these. With a view to the adoption of a series of standard testing sieves which might be of use to all industries making
How to Separate Liquid from Solids
For some years past the principle enunciated in the discussion referred to has been known to the writer and demonstrated by him to be an efficient and economical way of separating water or solution from solids in the cyanidation, lixiviation or acid leaching of ore pulps. In utilizing this principle in commercial practice he has invented a method whereby not
Desilverization of Lead Process of Silver Removal by Pattinson
Table of ContentsEquipment Used to Remove SilverMethod of OperatingHow to Operate a Desilverization PlanyGrade of KettlesCorrection of GradeDescription of an Operation and ProcessDrossFuelLaborLaboratory ExperimentsTredinnick – Pattinson Process as a Desilverizer When Hugh Lee Pattinson discovered, in 1829, that the crystals formed during the slow cooling of molten lead were poorer, and the remaining liquid richer in silver, than the original
Melting Copper Cathodes
Table of ContentsMelting under Coke CoverMelting under Charcoal CoverOxygen and Sulphur in the Melting of Copper Cathodes The melting of cathode copper, usually containing 99.98+ per cent. Cu, would appear to be a simple matter. Owing to the well known affinity of copper for sulphur, however, so much sulphur is absorbed by the copper during the operation that a long and
Mineral Vein Formation Mechanism
Table of ContentsMethods of Vein FormationSummary and Conclusions A vein may be defined as an aggregation of mineral matter, more or less tabular or lenticular in form, which was deposited from solution and is of later origin than the inclosing rock. This definition differs from the one found in many textbooks in that no assumption is made as to the origin of
How to Make Cement From Blast-Furnace Slag
Table of ContentsGranulating SlagSlag CementPortland Cement made from Slag and LimestoneIron Portland CementSpecial CementsSlag BricksDiscussion The successful establishment of iron blast-furnace plants at Newcastle and Lithgow naturally invites attention to the economic utilization of the various products and by-products arising out of the industry. The general similarity in composition between Portland cement and iron blast-furnace slag very early attracted attention both
Thickener Feedwater
The Quarto Mine and preparation plant of Quarto Mining Company is based on the production of coal from the Pittsburgh seam. At this location the raw coal contains a substantial amount of refuse with some troublesome characteristics. The refuse at the mine face (about 50% of the mine output) contains only a very small amount of very fine particles. As
Mill Tailings Storage for Reprocessing in Future
Table of ContentsEarly MethodsIllustration of SegregationKind of Tailings that may be SegregatedStoring and Importance of Milling SiteThe Cost of Segregation It is not my purpose to write a lengthy article or to attempt the solution of the problem I am presenting, but to call attention to what I believe an important issue, hoping that it may arouse in some one, or
Engineering Symbols
The Committee on Technical Nomenclature, of which John T. Faig, Professor of Mechanical Engineering at the University of Cincinnati, is Chairman, appointed by the Society for the Promotion of Engineering Education, has recently issued a report advocating uniformity in the use of symbols to designate engineering and mathematical terms: The selection of the symbols was based upon a canvas of
Electric Gold Melting Furnace
The furnace described in this paper was installed and has been used by the writer for the melting of rich gold-bearing material, and has given complete satisfaction. It may, therefore, prove of interest to other metallurgists who are faced with a similar problem. A furnace of this type should be most suitable for the reduction of “ cyanide precipitate,” “
How Base Metals Affects Gold Bullion Assaying
Table of ContentsWhat is the Effect of Zinc o Gold AssayDoes Cadmium Impact Assaying of GoldHow does Copper Affect Gold AssaysWhat does Lead do to Gold Assaying MethodsEffect of Silver og Gold AnalysisConclusions Having shown the difficulty of assaying so-called cyanide bullion and the extreme variations often found in the results, an investigation was undertaken to discover, if possible, the causes
Lead Refining Process
The building is a lofty, well-ventilated one of hardwood frame, with galvanized-iron walls and roof, and consists of five spans running north and south, covering a total length of 230 ft. Each span is composed of nine bays of 13-ft. centres, making the total width of the building 117 ft. The refinery is situated conveniently at a distance of 100
Counter Current Decantation
Table of ContentsCCD Wash Ratio DefinitionTheoretical ConsiderationsVariables Affecting Decantation ProcessMechanical FeaturesDorr ThickenerDiaphragm PumpsMeasurement of Solution PrecipitatedTray ThickenersDecantation Plant LaborPowerCostExtraction and RecoveryDiscussionGrade of Ore That Can Be TreatedDissolution in ThickenersCounter Current Washing and Leaching CalculationsApplication to Solution DilutionApplication to Solution Displacement The recovery of dissolved gold from slime pulp in the cyanide process was first accomplished by intermittent decantation. This simple process
Geology of Zinc Deposits MVD
I consider the lead and zinc deposits of the Mississippi Valley to be the result of descending waters. There are many features that we have not determined and yet when you see the general field relations, it seems to me that the cause and effect can be well explained by descending circulation. In the Joplin-Miami district, for instance, the ore
Ball Milling
Table of ContentsCrushing Action of Ball MillsConditions Determining Fineness of CrushingWhat Affects Ball Mill CapacityConditions Affecting Ball Mill PowerBall Mill CrushingHow to Feed a Ball MillConsistency of Pulp in Ball MillGrinding Ball ConsumptionBall Mill Liner Consumption These notes are based on observations made while on a recent trip through the West, for the purpose of studying the practical operation of the
Zinc Refining
Table of ContentsImpurities in SpelterMethods of Preventing Contamination of SpelterRefining Spelter by RedistillationConverted Smelting Furnace MethodDe Saulles MethodResults in Refining by RedistillationGrade of Metal ChargedGrade of Refined ZincYield of Refined ZincByproductsRedistilling MethodsMethods of Refining by Remelting Long ago, zinc refining had not become a general practice among the zinc smelters in the United States. Such refining as had been carried
Accounting for Small Mining Operation
Table of ContentsIncomeOperating ExpensesVouchers and EntriesDistribution of Power, Etc.Purchases and Inventories The observations here presented are not those of an expert accountant, but of one who, while he has seen considerable service in the accounting departments of large companies, has spent more time in engineering and operating. This paper is intended to cover, in a measure, mine accounting for small
Sizing Diagram from Different Screen Standards
It is a fair assumption that the main purpose of any diagram is to present facts to the eye in more convenient form than they could be tabulated in figures, and this implies that a screen diagram should set forth in a convenient and familiar form certain facts as to the character of the material screened regardless of the screen
Portable Miners Lamp
During the past years, the safe and efficient lighting of the coal mines of this country has received an ever-increasing amount of attention. Several States have passed laws attempting to regulate the type of lamp to be used and the nature of the fuel to be burned, and the mining departments of coal-mining States have generally shown a keen and
How Firing of Clay Affects it Microstructures
Table of ContentsMineralogical ChangesTemperature and Time FactorsScope of Present PaperMethod of ProcedureClays SelectedProperties of the ClaysEffects of FiringMicroscopic Examination of the Burned ClaysBrown ClayWhite ClayStages of Firing Clay Of the several interesting physical properties of clay which have claimed the attention of investigators in recent years, none is more important than the behavior of the material when heated to temperatures
Precipitate Refining Method
Table of ContentsRefining by AcidsRefining by FusionSinteringSlags This cyanide precipitate is unique in that it is apt to vary widely in composition in the course of very short periods of time, and a method of refining and melting that would prove highly satisfactory at one cleanup would yield almost a hopeless “mess” at a second. Table I gives a general
Iron Ore Magnetic Separation
Table of ContentsMagnetic Iron Ore ResourcesHistory of Development of Magnetic Separator Treatment Method DeterminationPresent Practice and State of DevelopmentWet Magnetic Separation of Cornwall OreDustLow Grade of ConcentratesResults of Dry Separation in Testing LaboratoryNo. 234, Separation Test on Jackson Hill Ore, Arnold, N. Y.Summary In the West, capitalists have expended many millions of dollars developing the low-grade porphyry ores of copper. Half a dozen
Tin Recovery by Gravity Methods
In a tin concentrator an appliance was needed to furnish a suitable product for fine jigging from a pulp of the following composition: In the jigging process, particles of cassiterite as small as 0.1 mm. can be recovered, provided they are not present in excess, that is if the material treated on the jigs contains sufficient coarser sands to keep
Metalliferous Ore Deposit Exploration
Table of ContentsCopperZincSilverGoldUranium and VanadiumIron and ManganeseNickelCobaltMercuryLeadAntimonyArsenicBismuthTinChromium, Molybdenum, Tungsten and Uranium The exploration of deposits of the metals will never become an exact science. There will always be an element of uncertainty in prospecting and developing mines. In countries where the surface has been closely scrutinized, most of the deposits whose outcrops contain valuable metals have probably been discovered. Many