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Effect of Impurities on Gold Slimes Refining Process
Table of ContentsEffect of SilicaEffect of Calcium CompoundsEffect of Magnesium CompoundsEffect of IronEffect of Nickel and CobaltEffect of AluminiumEffect of ZincEffect of ArsenicEffect of CopperEffect of LeadEffect of MercuryEffect of Bismuth and TinEffect of SeleniumEffect of TelluriumEffect of SilverWashing Out the Soluble SaltsTreatment of the Insoluble ResidueAmalgamation of Gold Slimes during the Refining ProcessEffect of Sulphate of LeadProportion of Coarse
Purify Gold Slimes to Make Bullion Gold Bar by Nitre Cake Refining Method
Table of ContentsPrevent Gold Losts by DustingEffect of Adding Nitre Cake DirectEffect of Temperature in the Nitre Cake MethodTime Required for the Nitre Cake MethodVessel Required for the Nitre Cake MethodLimitation to the Use of Iron VesselsDry Methods of Refining Gold SlimesRefining Gold with Boric AcidCaldecott’s Gold Refinement MethodTavener’s Gold Refining Process (Smelting with Lead and Fluxes)The Merril ProcessSlimes from Electrolytic Refining of CopperHow
Gold Slimes Refining & Acid Treatment of Precipitates
Table of ContentsStrong Nitric AcidStrong Sulphuric AcidDilute Sulphuric Acid and AirDissolving Out Gold with Chlorine Strong Nitric Acid Many attempts were made to further purify bullion slimes before smelting. The impurities present, as well as the gold, are in a state of fine division, and, therefore, adapted for solution. It might be assumed that copper and silver present could be
Treatment of Cyanide Precipitate AKA Gold Pregnant Solutions
Table of ContentsPrecipitation on ZincUsual Refining Method Now AdoptedImpuritiesModification of Acid TreatmentUse of Nitre Cake as a Substitute for Sulphuric AcidExperiments with Caustic SodaDistillation Process Comparatively little trouble was experienced in gold milling with regard to the preparation of a pure bullion until the advent of the cyanide process. When ores were smelted the litharge method of elimination of baser
Electrolytic Refining of Gold
The method just described aims at leaving gold in an insoluble state at the anode. Other impurities are usually left there, and the gold sponge, or slimes, needs further refining by methods, to be indicated later. By using a suitable electrolyte the gold can be dissolved from the anode bars and deposited in sheet form on the cathode, while many
Separating Gold from Silver by Electrolysis
Table of ContentsMoebius ProcessThe Improved Moebius Plant This attractive method of separating gold from silver has made some headway, and will in many cases replace other methods of parting. The electrolyte used is a solution of silver nitrate, or it may be started with dilute nitric acid. The cathode consisting of thin silver plate and the anode of the silver-gold alloy
Refining Gold with Sulphuric Acid
Table of ContentsParting Gold-Silver Alloy with Sulphuric AcidGold-Zinc AlloysGold, Silver, and SodiumEffect of Tellurium on PartingParting of Gold and Silver CommerciallyThe Gutzkow Refining Process Pure silver is readily attacked by strong hot sulphuric acid of SG 1.815, or about 90 per cent, strength. The reaction which takes place may be represented as follows: 2Ag + 2H2 SO4 = Ag2 SO4 +
How to Recover Silver from Nitrate Solutions
The usual method of recovering silver from these solutions is to precipitate the silver by means of common salt. From an ordinary alloy the only salts likely to be precipitated are mercurous chloride and lead chloride. The former would be present in traces only, and would be eliminated in subsequent operations. Lead is generally removed before smelting, but assuming any
Commercial Scale Gold Parting with Nitric Acid
Table of ContentsParting Zinc Cyanide BullionDouble Acid Gold Parting The method of gold parting with nitric acid usually consists in: Granulating the alloy, which should he free from antimony, tin, or sulphides. Treating with dilute nitric acid, and decanting the solution. Boiling with strong nitric acid. Washing the parted gold free from alloy. Smelting the parted gold. Recovering the silver
Gold Parting using Nitric Acid
Table of ContentsParting of Zinc and GoldParting of Zinc, Silver, and GoldParting of Copper and GoldSodium and GoldTellurium in Gold The process of parting gold with nitric acid is old, and probably dates from the discovery of nitric acid itself; it is one of the simplest parting processes, and does not require a costly plant or much manipulative skill. The
Miller Gold Refining Process by Chlorination
Table of ContentsEquipment and SuppliesFurnacesThe Crucibles and ConnectionsThe Chlorine GeneratorsPassing the Gas Through the Molten Metal The term refining has been very often applied to the removal of base metals from the noble ones, or, in other words, separating the oxidizable from the non-oxidizable ones. When used in this sense it is generally applied to the term bullion, which is
How to Refine Gold Bullion with Oxygen or Air
The how-to method of removing oxidisable metals by means of an oxidising agent has been practised for centuries. The operation has already been described in the cementation process with nitre, and the gaseous method of removing antimony from gold. The ordinary cupellation operations are also on the same lines. When oxidising fluxes are used, their action is limited, since the oxygen
How to Separate Silver & Gold by Cementation
Older processes explaining how to go about separating silver from gold by cementation were carried on practically in two ways, the first by heating gold for a long time with a mixture which evolved nitric acid on heating, and an absorbent into which any fusible salts ran; the mixture in the second method contained common salt as an essential ingredient, and
Common Uranium Minerals Classified by Colors
Name Chemical Composition %U3O8 Color Luster Hardness Specific Gravity SG Characteristics & Occurrence Pitchblende Uranium oxide 50-80 Black (Grayish, Greenish) Pitch like Earthy, Dull or Glassy 5-6 6-9 In Veins; often with Sulphides of Cobalt, Nickel,Silver, Bismuth or Yellow Secondary Uranium Minerals. Never Brownish or Reddish. Uraninite Uranium oxide 65-85 Black (Grayish, Greenish, Brownish) Pitch like Dull or Glassy 5-6 8-10
Sulphur Refining of Gold
Table of ContentsRefining with Sulphur and other Metals TogetherRefining with Sulphur and SodiumRefining using Sulphide of Antimony Refining with Sulphur A more speedy method of removing iron, copper, lead and base metals from bullion is to add sulphur to the molten metals. Although gold sulphides may be readily formed in the wet way, they are decomposed into gold and sulphur
Refining Gold with Oxidizing and Chlorinating Agents
Table of ContentsNitre RefiningRefining With Mercuric ChlorideRefining with Ammonium ChlorideRefining with IronRemoval of TinExperimental Chlorinating WorkRefining with Sodium BisulphateRefining with Sulphate of Silver and SaltRefining with Boric and Phosphoric AcidPhosphoric Acid and Oxidising AgentsBoric Acid and Oxidising AgentsPhosphoric Acid and Oxidising AgentsRefining with Potassium Chlorate Nitre Refining When the molten gold is obviously impure nitre is added, and as a
Simple Methods of Gold Purification
Table of ContentsRefining of Gold Obtained by Other Processes (Amalgamated Gold)Pan AmalgamationCopper Plate AmalgamationPurifying MercuryPurifying AmalgamRefining Retorted Gold The purification of such alluvial gold alloys is a simple matter. The high specific gravity of the metal allows of separation from most admixed materials by some process of elutriation, or water concentration, or, in arid regions, by dry blowing. The coarser particles
Froth Science
The little book on ‘Surface Tension and Surface Energy’ by Willows & Hatschek shows how the elastic film analogy in the study of froth will get one into no end of trouble if not handled with care. It is the characteristic of analogies to break down when pressed too far, though they are useful up to a certain point. This
Characteristics of Bulk Materials
Useful Table contains the Angle of Repose, Bulk Density and other Characteristics of various materials.
Mining Methods
Table of ContentsORE OCCURRENCEOREBODIESMINING METHODSOpen Pit MiningOpen Stoping and FillingUnderhand StopingShrinkage StopingSquare Set and FillSub-Level CavingRill StopingTop SlicingPanel SlicingDrilling and BlastingTimber and Timbering The mines and mining methods of the now defunct Arizona Mining Copper Co. are situated in the Morenci-Metcalf copper district in southeastern Arizona. This copper-bearing district covers a triangular mountainous area of about 3 square miles, rising abruptly
How to Operate a Merrill Crowe Precipitation Process
Table of ContentsMerrill Crowe Plant Design ParametersSIMULTANEOUS CLARIFICATION DE-AERATION and PRECIPITATIONEffect of CYANIDE STRENGTH and ALKALINITY in Merrill CroweFEEDING ZINC DUST in a Merrill Crowe PlantUSE OF LEAD SALTS in Merrill Crowe ProcessingEFFECT OF COPPER ON PRECIPITATION on Merrill CroweEFFECT OF LEAD ON PRECIPITATION in Merrill CroweTREATMENT OF Merrill Crowe PRECIPITATETYPES OF BULLION MELTING FURNACESMELTING FLUXESTESTING Cyanide SOLUTIONS IN Merrill CroweDOWSETT’S ESTIMATION OF GOLD IN CYANIDE