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Amalgamation Pan
Table of ContentsAmalgamating PanOperating an Amalgamation PlantSummary of Amalgamation TestsConclusion The aim of instruction in a metallurgical laboratory is to make real the principles on which metallurgical processes and operations are based, and to foster the spirit of investigation. The materials with which experiments are carried out are ores, metals, and metallic compounds. The method varies with the end sought. A class
Jigging Minerals: Galena – Sphalerite
Table of ContentsMineral Jig Pulsion & SuctionDiscussion of AccelerationResume and Conclusions Summarizing some of the principal points brought out in this laboratory Jigging of Minerals’ investigation, I believe the following may safely be accepted: The pulsion-reaction is by far the most important one in the process of jigging. During this period, with sized grains of different specific gravities, with proper pulsion-velocity, the
CuSO4 Electrowinning with Crystallization of Bleed
Commercial copper SX reagents do not exhibit perfect selectivity. From typical acidic feed solutions, the most significant co-extracted impurity is ferric iron. The copper/iron extraction ratio for a given reagent operating in a countercurrent circuit will vary significantly with reagent content of the solvent, composition of the feed solution, organic/aqueous flow ratio, temperature, mixer retention times, mixing intensity, etcetera. For
Volatility of Metallic Chlorides
In Table I are cited data on the vapor pressures of the common metallic chlorides. The temperatures given are in the region of magmatic temperatures, except where a high vapor pressure is developed at a much lower temperature. Because of the volatility of chlorides, and because direct observation of volcanic sublimates shows their presence, it is deemed probable that chlorides
Jigging
Table of ContentsTesting Minerals for Jig RecoverabilityResume of the Results of Previous Preliminary WorkHydraulic ClassificationPulsion Jig TestsVezin Laboratory Jig TestsFull suctionPart suctionBalanced suctionJig SuctionFeed Water and Rate of Feed to JigJig Filter-BedLength and Number of Jig StrokesMineral ConcentrationSpecific GravityExperiments with a Five-Sieve Harz JigExperiments with the Jarvis Laboratory-JigHow to Make/Build a JigScreensSieve-SizesJig BeddingMineralsSpecific GravitiesJig FeedMethod of Conducting a Jigging TestRecord of Results
Economic Geology
Understanding the feed to processing operations is key to maximizing cash flow (economic value). Unfortunately the subject of economic geology is not covered within most undergraduate programs preparing students who enter the mining industry as process engineers. The good news is that there are reference materials available to help people learn these subjects. Some good examples are provided below: A
Overpoling Electrolytic Copper
The current meaning of the term, copper overpoled in the reverberatory furnace, is that poling has been carried beyond the tough-pitch stage, with the result that the reduction has been carried too far, causing the copper to become porous and brittle, and thus unfit for industrial purposes. It will be shown that the brittleness of furnace-overpoled electrolytic copper must generally
Hydraulic Jig Concentrator VS Shaking Table
Table of ContentsSkaking TablesDifference Between Hydraulic Jigs & Shaking TablesBelt for Treating the SlimesSeparation of the Middlings Concentration of grains from 10 to 30 mm. is effected by hydraulic jigs with two compartments, and in the case of the smaller grains down to 2 mm. by jigs with five compartments. The construction of the jigs is the same in both cases. Fig. 3
Difference between Crushing and Grinding
When making comparisons of the efficiencies of different grinding and crushing machines it is desirable to be able to estimate the work actually done in crushing the ore from a given size of feed to a given size of product, the screen analysis of both feed and product being determined. Messrs. Klug and Taylor, in a paper on this subject,
Underground Gold Mine Development Sampling & Ore Valuation
Table of ContentsDevelopment SamplingOre-Valuation This paper is intended, in the light of recent investigations, to call attention to some of the essential features of good practice in sampling and mine-valuation. Mine sampling may be divided broadly into two classes: development-sampling and computation of ore-reserves; and, stope-sampling and estimation of stope-values. Development Sampling It is with development-sampling only that this paper
Assaying Gold & Silver from Copper Alloys
The so-called “combination method” is generally used in assaying bar copper for silver. It has been modified from time to time. Briefly outlined as now practiced, it is as follows: One A. T. of the borings is dissolved in dilute nitric acid. When solution is complete the liquid is boiled and then filtered to remove gold. The filtrate is treated
How to Assay & Evaluate a Gold Bar: Bullion Purity Determination
The Bureau of the Mint of the United States Treasury maintains offices for the purchase of gold-bullion, and this paper describes an investigation to establish the reasonable differences in the assay-results at the various institutions which may be commercially allowable in the settlements between them. Beginning with the comparative assay of proof-gold at the Philadelphia mint and the Utrecht mint,
Adjustable Thermo-Electric Pyrometer
Frequently in using a thermo-electric pyrometer for measuring the temperature of a furnace, a hole is drilled at the back or side of the furnace, through which is introduced the tube containing the thermocouple. At times the couple is left almost where it drops, for the reason that it soon becomes too hot to be handled easily, and the space
Refining Electrolytic Copper
Table of ContentsStudies in Refining Electrolytic CopperRefining-Charge No. 1Refining-Charge No. 2Summary of Refining-Charges Nos. 1 and 2Studies in Overpoling Electrolytic Copper The object of refining copper in the reverberatory furnace is to obtain a metal which will have the highest attainable degree of malleability, ductility and electric conductivity, and present at the same time a level surface when it solidifies
Roasting Galena Concentrate with Lime
Table of ContentsExperimental WorkRecord of ResultsConclusion Lime Roasting is a term proposed by Ingalls for the operation of forcing air under pressure through a mixture of galena and lime at the kindling-temperature with the object of oxidizing lead and sulphur and of fritting or fusing the charge. If finely-divided galena were treated in this manner without the addition of lime,
Effect of High Litharge & Silver Assay Crucible
In the crucible-method of assaying ores for silver a certain amount of litharge is essential to supply sufficient lead to collect the precious metals. The object of this paper is to point out that the use of a large excess of litharge in the assay of some ores will give results for silver that are uneven as well as low.
Laboratory Gold Ore Chlorination Testing Procedure
Table of ContentsRoastingChlorinationLeachingTreatment of TailingsDiscussion of Test & MethodTests for Quantity of Bleach and of Sulphuric AcidTreatment of the Gold Chloride SolutionBarrel Test Experience has shown how difficult it is to obtain information regarding laboratory tests in connection with the chlorination-process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of
Tin Ore Processing
The methods employed in dressing the tin ore up to the required percentage of purity depend mainly on the type of ore crushed. These may be briefly divided into two distinct classes—viz., a free milling ore and a complex milling ore. In the former the ore is practically free from the common metallic sulphides, such as. pyrites, mispickel, blende, galena,
Small Mining Drills
The purpose of this paper is to discuss the relative merits of the large 3 1/8-in. machine and the small mining drill 2¼-in. tappet machine in driving development-headings; and although the data here presented were obtained from cross-cut headings alone, experience has shown that the results are equally true in drifting, raising and winzing. Recently we drove two parallel cross-cuts
Refining Base Metal Bullion & By-Product Treatment (Pb, Cu, Zn) Bars
Table of ContentsThe Silver Skims Form Another CycleGold PressingsGold PartingTreatment of Antimony DrossTreatment of Silver Retort DrossHoward PressHoward Stirrer Here is a short account of the treatment of the base bullion for the recovery of lead, silver, and gold, and for the treatment of by-products. Appended is a short description of the chief facilities of plant which have been adopted to
Gold Leaching of Pyrite Concentrate
The ore consisted of quartz, in which, above the 250-ft. level, the iron-minerals were largely oxidized and some free gold was visible; below that level few traces of oxidation occurred, and pyrite constituted the principal mineralizer in the quartz, together with occasional pockets of galena and a few eccentric specks of covellite. The 20-stamp mill was equipped with plates for
Iron Crystallography
Table of ContentsDeformation FiguresCongenital TwinningTwinning Resulting from Annealing after DeformationMechanical Properties Functional of the Crystalline OrientationSynchronous Crystalline FiguresSegregation FiguresExperimental SectionContinuous Crystalline Deformation; SilhouettesDiscontinuous and Effaceable Deformation FiguresNon-Effaceable Deformation Figures: Mechanical Twinning Congenital TwinningTwinning Resulting from Annealing after ReformationMechanical Properties Functional of Crystalline OrientationCorrosion FiguresSynchronous Crystallization FiguresSegregation FiguresSummary We have already devoted two previous memoirs to this question. In the first we
Cost Accounting in Mining
Table of ContentsMILLINGPLANT AND DEVELOPMENTSTOPINGDISTRIBUTED ACCOUNTSList of Forms In the zeal for opening up new ore-bodies, or for extracting the ore from attractive bodies already opened up, we very often lose sight of the fact, that, after all, the operation of a mine is a business proposition, pure and simple, and, for the best working-results, should be treated upon a
Bromine Cyanide Gold Leaching: Cyanogen Bromide
Table of ContentsBromo-Cyanide SolutionEffect of adding Lime Although the bromo-cyanide or Diehl process for the extraction of gold from its ores is used on several of the Kalgoorlie mines, very little information has been published on the original process, and no details are available from the various mines now using it. The following description of the process as carried on