Blogs
Six-Spheres – Cylinder & Piston – Compressive Strength Test
Six-Spheres test: The conventional test consisting of compressing the pellet between parallel flat platens does not simulate very well the environment actually encountered by the pellet. Each pellet is surrounded by similar pellets, that exert a pressure on it whose magnitude is dependent on the height of the pile, among other parameters. The most compact ways in which spheres pack themselves
CMI Centrifuge
The CMI centrifuge is a positive discharge scroll type centrifuge employing a profile wire screen mounted within a basket which is fastened to an outside rotating frame and an inside solid cone equipped with spiral flights. The belt driven gears produce a differential speed in the two (2) rotating elements. Both elements rotate in the same direction, however, the screen
Cone Crushing, Rod Milling and Ball Milling Laboratory Testing
The two largest cost components in comminution circuits are energy consumption and metal wear which, for cone crushing, rod milling and ball milling, can be established by conducting laboratory bench scale tests. Pilot plant testing for these comminution methods is not normally required. Laborary testwork performed by Allis-Chalmers to identify these parameters are covered by: work index tests for energy
Chromite Flotation
Table of ContentsFlotationMicroelectrophoresis procedureAdsorption testsLaboratory ExperimentDiscussionExperimentation on Gangue Minerals Associated with ChromiteElectrokinetic StudiesAdsorption of Sodium Dodecysulfate (SDS) Onto Chromite MineralsFlotation of Gangue Minerals Associated With ChromiteGangue Minerals Performance ReviewEffect of Ionic Species on Electrokinetic BehaviorAdsorption Studies on Gangue MineralsEffect of Multivalent Ions on Adsorption of SDS onto Gangue MineralsFlotation Studies on Gangue MineralsConclusions Careful studies of the fundamentals of chromite flotation
Diamond Dredge
With regards to diamond dredges and dredging, the kings of the 1970s were Consolidated Diamond Mines and Marine Diamond Corp. both parts of the famous DeBeers company, control the coast of the Namib Desert and the waters and more important, the ocean floor and beaches of this treasure cheat of gems. So rich were the original finds that diamonds could be
Ceramic Mold Inserts
Table of ContentsSelection of MaterialsDevelopment of Computer ModelCeramic Materials TestingSmall ScaleLarge ScaleBoron CarbonitridePyrolytic Boron Nitride (PBN)Conclusions For many years, the diecasting process has been employed by the nonferrous foundry industry. In this process, castings are produced by forcing molten metal under high pressure into reusable permanent metal molds commonly called dies. Figure 1 shows the sequence of steps normally used
How Ball Mill Ore Feed Size Affects Tonnage & Capacity
The important of crushing your ore and rock fine and properly is often forgotten. The finer you crush, the higher your ball mill tonnage and capacity will be. The effect of ball mill feed size and how it affects circuit throughput can be hard to estimate. Here we described a method of designing a crushing plant using power drawn and
Induction Heating in Fire Refining of Silver & Gold
The use of induction heating as an alternative to gas or oil fired heating for the fire, refining of precious metals is attractive for several reasons: (1) compactness, (2) less waste heat, therefore cooler room temperatures, (3) cleaner operation, (4) no off-gas discharge, (5) energy efficient as less material heated and (6) less time to reach temperature. The particular application
Carbon in Pulp Plant
Table of ContentsElectrowinning CircuitCarbon Reactivation Sslurry at a rate of approximately 3.785 cu. m. per minute (1,000 GPM) is placed in contact with activated carbon. A simplified flow-sheet of the CIP Plant is shown in Figure 2. For years it has been known of the affinity of activated carbon to adsorb preferentially the gold and silver in cyanide complex form.
Knelson Concentrator
The Knelson Concentrator relies on an enhanced gravitational force together with fluidization process to recover even very micron sized particles. First water is injected into the rotating concentrating cone through series of fluidization holes. Then feed slurry is introduced through a stationary feed tube. Once the slurry is filled in each cone, create a concentrating bed and high specific gravity particles
Recovery of Cadmium from Scrap Batteries
The manufacture and use of nickel-cadmium alkaline batteries began to grow in the late 1950’s. During the period from 1966 to 1971, approximately 3 pct of the U.S. primary cadmium demand was consumed by battery manufacturers. From 1971 to 1975, the demand grew from 3 pct to 13 pct. It was estimated by the battery manufacturers (1) that by 1981
Rock Splitting
Rock splitting utilizes a tensional force to crack the rock. This is achieved by inserting a split steel shank in a drillhole and driving a steel wedge between the center of the split shank thereby producing the tensile forces. The advantages of the rock splitting technique over blockholing are the absence of explosives and the reduction of downtime provided there
Rock Grapple
A rock grappler is a claw shaped device used for picking up boulders. The grasping mechanism of a grappler is generally activated by a pneumatic or hydraulic cylinder, as shown in Figure 17. The cylinder is connected to each half of the claw and when activated forces the claw shut. Grapplers are used to remove or reposition boulders; they can
Rock Hammering & Rock Breaking
The rock hammering method of boulder breaking is a process of hammering the boulder by either a hydraulic or pneumatic hammer until the boulder breaks. The hammer is usually mounted on a boom. The motor, hydraulic pump, and oil reservoir are usually located near the boom. Figure 14 shows a typical hammer installation. The advantages of this method are continuous
Rock Boulder Blasting with Explosive
Table of ContentsBlockholingSnakeholing or BombingMudcappingBlasting Mats Boulders can be broken up using either explosives or mechanical methods which can be implemented in many ways. Handling boulders hung up in crushers is inherently inefficient for the overall operation, and the techniques in handling them each have their own advantages and disadvantages. Table 4 shows a comparison of explosive boulder breaking techniques.
Rock Boulder Exploding Techniques
Table of ContentsBinary ExplosivesExploding Bridgewire CapsNonelectric SystemsExplosives MethodsEnergetic ExplosivesRibbon Explosives (Military)Shaped ChargesLinear Shaped ChargeContained ProjectileNon-explosive MethodsElectron BeamSparkFlame JetBurning BarREAM ProjectileElectrical DisintegrationWater and Air JetsBreakage by ExpansionRecommendations for Safer PracticesImproved AccessibilityFormal Adopted ProcedureImproved Blasting MethodsOther ConsiderationsRecommendations for Further ResearchHome-Made DevicesExplosive Use ResearchEconomic Study Several products have come on the market in recent years that improve the safety of secondary blasting operations.
Rock Boulder Crushers
Table of ContentsRock CrushersDelivery SystemsRock Crusher TypesGyratory CrushersJaw CrushersRoll CrushersHammermillsRock BouldersSourcesDelivery In mining and quarryinq, the mineral commodity as present in the ground may be composed of rock blocks that must be reduced in size, to suit market requirements. The rock in place will be blasted, loosened, and then hauled away to the first processing step-size reduction. As delivered from
Arsenic Pyrite Gold Extraction by Alkaline Leaching Oxidation
Table of ContentsLeaching Chemistry and Process ConsiderationExperimental ProceduresElectrochemicalLeachingPrecious Metal ExtractionArsenic and Sulfur Separation and RecoveryEpa-Tclp TestAnalytical MethodsResults and DiscussionElectrochemicalLeaching of High-Grade OreRate of Arsenic Extraction and Activation EnergyPrecious Metal ExtractionLeaching of Low-Grade OreArsenate PrecipitationSulfate PrecipitationEPA-TCLP TestFlowsheet and Reagent RequirementsConclusions Gold mining uncovers more and more hydrothermal deposits in which gold mineralization is associated with sulfides and other compounds of base
Magnetic Fluids Experiment
Table of ContentsMagnetic FluidsMagnetic Separation of the Second KindMagnetic Levitation ForceMagnetogravimetric SeparationsExperimentElectromagnet Powered Magnetic Fluid Separation UnitMaterial Feeding and Discharge SystemsReagents and MaterialsNonferrous Automobile ScrapUpgrading Diamondiferous ConcentratesSummary and Conclusions Man’s material wealth has usually started with fairly concentrated ore bodies that are mined, beneficiated, refined, and then manufactured into material objects. Following their use and abuse, the objects are discarded
How to Transport Lime
Table of ContentsBarge TransportationRailroad TransportationTruckDump TruckPneumatic Truck Lime is transported in large volumes by the three common surface modes, i.e., barge, railroad, and truck. Barge Transportation Barges used in lime transportation have a capacity up to 1,500 tons and 1,400 ton loadings are very typical. The hulls of the barges are double skinned and constructed with water-tight sections. This type
Understanding the Gold Centrifuge by Comparing it with a Sluice Box
Table of ContentsCompare Gold Recovery EquipmentGold Size by Size Recovery Centrifugal separation of gold experienced a regain in activity with the advent of the Knudsen Bowl. This device appears extremely efficient in recovering fine gold, although very little published data are available. Installing a gravity plant increased overall gold recovery by about 3-4% in some plants. Gravity concentration was achieved
Extraction of Chromium from Chromite Ore
Table of ContentsOre SamplesChromite Ore ProcessingShaker Table Concentration of Dry Crushed OreChromium Ore MetallurgyConclusions Chromium has a wide variety of applications in the modern world. Its major uses are in stainless steels and the plating of metals. Other important uses include alloy steel, heating elements, pigments, leather processing, catalysts, and refractories. Of the chromite ore imported into the USA, the
Hydraulic Dredge Design
Let us assume that it is desired to design a hydraulic dredge capable of raising average hydraulic material 15 feet above the pump through 4000 feet of pipe line and at the same time be suitable for general all round work involving also short lines and low heads. It is generally accepted that a 20 or 22 inch pump is
Scows
The most common conveyance for the transportation of dredgings (pumpings excepted) is the bottom-dump mud scow. It is in effect a hopper barge, without means of self propulsion, consisting simply of a hull rectangular in plan and cross section, containing a number of independent hoppers called pockets, and with both ends raked or rounded (in elevation) for towing in either