Blogs
Gold Metallurgy & Leaching in Cyanicides
Table of ContentsRecovering Gold from Iron SulphidesHow Thiocyanate Affect Gold LeachingUsing Lead Salts in Gold LeachingHow Ferrocyanides influences Gold LeachingEffect of pre-aeration on gold leach recoveryHow the method of pre-lime treatment affects gold leachingDirect Leaching in Grinding CircuitA trick to reduce cyanide consumptionGold Leaching with Copper Minerals presentLeaching gold in CalcineLeaching Gold with Zinc Minerals in OreHow Lead Minerals Affect Gold Leaching & RecoveryGalena (PbS),
HPGR
Table of ContentsWhen is HPGR better than Ball MillOptions for Plant Design/ Upgrading of Comminution CircuitsOperating Modes of the Polycom HPGR in a Gold PlantPolycom Amenability Tests for Gold Ores HPGR or high-pressure grinding rolls have made broad advances into nonferrous metal mining. The technology is now widely viewed as a primary milling alternative, and there arc a number of large
Gold Shaker Tables
Table of ContentsBumping Shaker TablesWhy are Riffles Important for TablingVanner Gold Shaking Table Overflow from the grinding mill runs over Gold Shaker Tables which are flat and smooth and made of a fibrous wood known as “yolombo.” They are arranged in series much the same as blanket or amalgamation plate tables. The grain of the wood in the deck runs with the
Gold Flotation
Table of ContentsGOLD FLOTATIONGOLD FLOTATION MACHINESCalculating Flotation-cell RequirementsGOLD FLOTATION REAGENTSREAGENTS USED IN FLOTATION OF GOLD ORESFrothers and Froth ModifiersREAGENTS FOR SILVER ORE FLOTATIONPRECIPITATING EFFECT OF FLOTATION REAGENTSPRIMARY SLIMEGOLD FLOTATION FLOWSHEETFlotation Unit in the Grinding CircuitFlotation of Cyanide Residues Though the gold recovery methods previously discussed usually catch the coarser particles of sulphides in the ore and thus indirectly recover some
Gold Recovery Methods
Table of ContentsRecovery of Free GoldRecover Gold in SulphidesRecover Gold by GravityRiffle or SluiceHydraulic Gold TrapConesThe Unit Flotation Cell and Hydraulic ConeJigsJig CapacityMechanical Condition of the JigUsing CORDUROY Sluice Mat GOLD SAVERCONCENTRATION Method of Applying Corduroy on Sluice Regardless of subsequent treatment, it is considered best to recover free gold as early and as completely as possible in the flow of
High Rate Thickeners
Table of ContentsLamina ThickenersSolids Re-circulation ThickenerSelective Recirculation Thickeners There are two basic types of high rate thickener units: Lamina or tube settlers and solids recirculation units Lamina Thickeners They contain space-cutting baffles that intercept settling paths at many levels. Solids settle out onto the baffles and are removed from suspension after settling only a short distance. Where and to the
CCD Filtration System
Table of ContentsFiltration MediaFilter ClothStage FiltrationFilter TypesPressure FiltersVACUUM FILTERSLeaf Filers Butters filter Slime treatment, as commonly used by metallurgical engineers, includes thickening, agitation, and filtering and as applied, to cyanidation also includes washing by continuous countercurrent decantation (C.C.D.) and/or filters. “Slime” is the general term used to describe the finer portion of pulp in a combination sand and slime-treatment plant and
Thickener Underflow Pump
The diaphragm Thickener Underflow Pump is essentially one for low lifts and is particularly adapted to handle metallurgical pulps economically and with minimum attention. The Dorrco diaphragm pump was developed primarily as a means of controlling the density of the underflow from the Dorr thickener in the first continuous treatment of cyanide pulps. It has been proved the most satisfactory
Counter Current Decantation Design Formula
Table of ContentsCounter Current Decantation ApplicationsDissolution during Washing The principle of Counter Current Decantation is simply that, when water or solution is to act upon solids, both are made to pass, in contact, in opposite directions, so that at each end the strongest or most potent portion of either is acting upon the weakest or most exhausted portion of the
Rotary Disk Filter Flappers
The concentrate is filtered on two 8 by 10 ft. Oliver filters. One of these filters is used for each roaster. The filter cake discharges onto a conveyor belt which feeds the charge directly to the roaster. The concentrate filter cake is at best a sticky, puttylike mass. If the moisture exceeds 20 per cent it becomes difficult to handle
How a Thickener Works
Table of ContentsThe Workings of a ThickenerFactors affecting Thickening rates Thickening or dewatering may be defined as the removal of a portion of the liquid from a pulp or slime made up of a mixture of finely divided solids and liquids. The early methods of thickening employed plain, flat-bottomed tanks into which the pulp was fed until the tank was full.
Gold Leaching Agitation Tanks
Table of ContentsMechanical AgitatorsPachuca Leaching TankThe Dorr Leaching AgitatorNoranda TypeContinuous Versus Batch Agitation Leaching The mixing of solids suspended in a fluid medium is still largely an art. The development of fundamental laws governing the operation is complicated by the large number of variables involved, some of which can hardly be evaluated in mathematical terms. Practical studies of the circulation
Leaching Agglomerated Slimes
More recent work along these lines is reported in T.P. 790, A.I.M.E.’ by 0. C. Shephard and C. F. Skinner presented at the New York meeting in 1937, under the title of “Stabilizing Agglomerated Slimes for Gold Cyanide Leaching.” The paper describes the development of a method of stabilizing agglomerated slimes by the formation of a cementing substance in the
Vat Leaching of Finely Crushed Gold Ore
Vat leaching is carried out in vats ranging in capacity from 30 to 1200 tons. Sand for leaching is separated from slime in cones, V boxes, classifiers, and in collecting vats filled by distributors—the overflow in each case being slime or finer portion of the ore. As a rule, leaching is a simple process, involving a vat of well-mixed neutralized sand,
Leaching of Clay Ore
Table of ContentsVatsChargingDischargingExtractor House To solve the problem of treating and leaching a clay ore in which the gold was finely disseminated, the author was able to suggest a unique method which he had seen described twenty-five years previously in a paper, “Occurrence and Treatment of Gold Ore at Bidi, Sarawak, Borneo,” by T. C. Scrutton, which appeared in Trans.
Hydraulic Classifiers
Table of ContentsDorrco SizerHYDROSEPARATORSWhat are Hydraulic ClassifiersWhen to your a Hydraulic Classifier for CLASSIFICATIONOpen-circuit GrindingClosed-circuit Secondary MillsClosed-circuit Primary MillsIntermediate Classification between Stages of Fine GrindingFinishing Bowl ClassifiersMEANS OF CLASSIFICATIONCONE Shaped Hydraulic ClassifiersScrew ClassifiersReciprocating Rake ClassifiersHardinge ClassifierDESLIMINGDesliming for Separate Treatment of Primary SlimeCENTRIFUGAL CLASSIFICATIONBird CentrifugeDSM Cyclone Hydraulic classifiers range from simple V-shaped launders with a multiplicity of shallow settling pockets for the discharge of as
Dewatering Screw Classifiers
Dewatering Screw Classifiers once had a wide vogue and still are used in some pulp circuits. They were more or less troublesome because solids tended to accumulate on the sloping sides, sloughed off periodically, and plugged the discharge in the apex; the sand discharged was too dilute and contained too much slime; and sand was frequently carried over with the
Cement Clinker Grinding Aids
Table of ContentsHow Grinding Aids Affects Dry GrindingEffect of Grinding Aids on Wet GrindingEffect of Grinding Aids on Cement Clinker Grinding The use of a good Cement clinker grinding aid can be vital in today’s increasing material demands. Along with the obligation to process increasingly larger quantities of ores containing finely disseminated minerals, our limited energy resources and the rising costs of energy
Crushing Efficiency Factors
Toward the foregoing goal, engineers investigated the energy efficiency of crushing for less than ideal cases. In the first experiment they studied the effect of factors such as using a deep bed of particles, a situation usually present in a ball mill. The same type of slow crushing experiment described above was performed, but with a bed five or six particles
Ore Sorting & Pre-Concentration
Table of ContentsSORTING ORE IN THE FLOWSHEETOre Sorting on the RandOre Sorting at RandfonteinOre Sorting at McKenzie Red Lake, Canada.THE ECONOMICS OF Ore SORTING & Pre-ConcentrationORE SORTING BY SINK-FLOAT for Pre-Concentration Ore Sorting helps the economics of mining when ore becomes diluted by country rock because of narrow slopes or because of weak wall rock, or when it naturally contains barren
Crushing & Screening Plant
Table of ContentsWhere to Position the CrusherHow to Feed a CrusherPrimary CrushingCrushing UndergroundCrushing on SurfaceSecondary CrushingTertiary CrushingCommon Crushing Plant Design & LayoutNew Crushing Technologies Methods used in Crushing & Screening Plants on ore range from a simple combination of a grizzly and one crusher to an elaborate arrangement in series of grizzly, jaw crusher, screens, and rolls or cone crushers. Crushing is done underground
Gold Precipitation Test
Table of ContentsFiltering apparatus for gold precipitateGold Settling-test ProcedureThickening CapacityReagentsFilter Tests and Calculation The following method of testing the precipitation of gold in pregnant cyanide solutions has been adopted by the Ore Dressing and Metallurgical Laboratories, Bureau of Mines, Ottawa. The apparatus consists of three Erlenmeyer flasks of 3000-cc capacity (see Fig. 5). Flask A is for evacuation of air from the
Heap Leach Amenability Test
In cases where fine grinding is not necessary to liberate the gold values, it is often possible to classify the coarsely ground ore into a sand and slime product (at, say, about 200 mesh) treat the former by so-called percolation leaching and the latter by the agitation method that has been described above. This is also called a Heap Leach Amenability
Gold Leaching
Table of ContentsAgitated Gold Leaching TestsDetermine Lime Comsumption of an OreHow to Determine the Cyanide and Lime ConsumptionSeries Gold Leach TestingAddition of Gold Leaching AgentsChange of Gold SolutionGrinding in SolutionTesting for Gold Reprecipitation The following gold leaching test procedure has been found satisfactory for carrying out cyanide leaching tests by agitation. Winchester bottles of about 2.5- to 4-liter capacity are used. It is