Blogs
Installation of an Underground Crushing System
Table of ContentsCrusher and Conveyor System LayoutDecline Chosen to Develop Crusher LevelLonghole Methods of Excavating Meramec Mining Company, a joint venture by Bethlehem Steel Corporation and St. Joe Minerals Corporation, is engaged in the mining, concentrating, and pelletizing of iron ore from the Pea Ridge Mine located near Sullivan, Missouri, about 70 miles southwest of St. Louis. Crusher and Conveyor
Surface Oxidation of Chalcocite
Table of ContentsProducts of OxidationExperimentalExperimental Results For sulfide minerals, the presence of dissolved oxygen in the water phase is an influencing factor for separation by flotation, Klassen and Mokrousov distinguish three stages of oxygen adsorption; namely, reversible adsorption, activated adsorption and, finally, surface oxidation. While contraversial, limited adsorption of oxygen is believed to improve the interfacial reactivity between collector and
Use of Simulation Models to Design, Optimization and Control of Wet Grinding Circuits
Table of ContentsMathematical Model of ComminutionCircuit Optimization Mineral comminution is an important and expensive industrial process and modern comminution circuits are complex. There is considerable economic incentive to optimise circuit design and performance and to operate circuits at maximum efficiency, and these aims may be achieved by setting up mathematical models of the volts in a circuit on a digital
Particle Size Distribution of Grinding Mill Products
Table of ContentsMethod of Analysis of Size Distribution DataSize Reduction by Impact CrushingSize Reduction by Ball Mill GrindingSummary This report briefly reviews the essential features of moment analysis and describes extension of this method to size reduction by ball mill grinding. Method of Analysis of Size Distribution Data Size analyses of mineral products are usually made by screening with a
Optimizing Grinding and Regrinding Capacity in Mill Design
Table of ContentsOptimizing Primary Grinding CapacityEstimate Total Grinding Cost (including Regrind) Versus Primary GrindOptimizing Regrinding CapacityRelation to Project OptimizationOptimizing for Flexibility The intent of this paper is to try to answer the complex question: “How much grinding capacity should be designed into a new mining – milling project?” Much work has been devoted to the technical aspects of grinding, the “how”
Open Storage Piles and Dust Control
In discussing the open storage dust problem and possible solutions, one obvious question arises – what are the economics of placing large bulk storage under cover? Several known, practical, workable solutions to the open storage dust problem are described. These include the following which will be dealt with in some detail: A. Open pile surface crusting agents B. Open pile surface
Nitric Acid Processing Copper Concentrates
Table of ContentsExperimental TechniqueThe Leach StepPressure Leaching AttractiveProcess Development The process parameters for effective utilization of nitric acid as an oxidant for copper-iron sulfides have been developed. Leaching variables found to be important were acid concentration, temperature, time, atmosphere, pressure, mineral type, particle size, and percent solids. Particular attention was devoted to analysis and control of fumes evolved during the
Magneto-Gravimetric Separation of Nonmagnetic Solids
Table of ContentsHydrodynamics of Magnetic FluidsThe Magnetic Levitation ForceExperimental WorkResults and DiscussionSome Properties of the Magnetic FluidLevitation ExperimentsConclusion Stable colloidal solutions of ferromagnetic or ferrimagnetic materials are called magnetic fluids. About two generations ago, suspensions of relatively large micron-sized ferromagnetic particles in oil proved useful in clutches, brakes, and dashpots. They were called magnetic clutch materials, and their viscosities were
Design Start-Up and Operation of the Hygas Pilot Plant
The HYGAS Process is one of several coal conversion processes now under development within the United States and is the most advanced in development. It is based on the overall reaction of coal and water to produce methane, which is the major constituent of natural gas,and a by-product, carbon dioxide, which is exhausted to the atmosphere. This overall reaction (Reaction
Wet Magnetic Separation
In essence, any magnetic separator operates on the basis of imparting a preferential magnetic force on particles of higher magnetic susceptibility which are to be separated from particles of lower magnetic susceptibility. A certain amount of directional deviation to the particles takes place thus allowing for collecting each category of particles separately. Under fixed feeding conditions of same particulate
Techniques to the Extraction of Values from Municipal Refuse
Table of ContentsUnburned Refuse FlowsheetSummary and Future Plans Incineration has, in recent years, been considered by many as a major source of air pollution. However, a number of reports refute this belief. The former report states that the National Academy of Sciences has published data showing that refuse combustion accounts nationally for only 2.6 percent of air pollutants. The report
Electric Drives for Large Ore Grinding Mills
Table of ContentsMill Power Transmission ArrangementsRequirements for Successful Mill DriveStarting Effect on Mill Mechanical PartsInitial CostLoad SharingRisk AssessmentEvaluation and Selection Ore grinding mills are really just slowly rotating barrels, but barrels that are growing in size so fast that the application of electric drives for them is rapidly approaching a technology like that for wind tunnels or pumped storage drives.
The Effect of Lime on Reduction of Iron Ore Pellets
Table of ContentsTest Methods Employed for Determining the Metallurgical Properties of PelletsEffect of Lime Addition upon the Behavior during Reduction of the PelletsAttempt to Interpret the Causes of Swelling, Loss in Strength and Grain Disintegration For the commercial production of iron ore pellets from hematite ores, as it is practiced in various pellet plants, the addition of lime has shown
Effect of Dolomitic Lime on Magnetic Taconite Pellets
Table of ContentsEquipment and ProcedureMaterialsBench Scale StudiesPilot Plant StudiesFlowscheme and EquipmentOperationResults and DiscussionMechanical Properties of Green and Fired PelletsGreen Pellet QualityFired Pellet QualityMetallurgical Properties of Fired PelletsHigh-Temperature Linder DegradationLow-Temperature Linder DegradationModified Linder DegradationReducibility and Swelling PropertiesMagnesioferrite ReductionConclusions For maximum blast furnace productivity it is generally believed that the iron oxide pellet should contain as many of the ingredients of the
Chemical – Quality Control of Metallurgical Wastes
There are generally four operational units in Butte: underground mines, open pit mine, concentrator and precipitation plant. As with copper production, the waste water systems for all units are interrelated. Acidic mine water is pumped up the Kelley shaft and distributed on leach dumps. Major waste water discharges from the Butte operations include: about 4400 gallons per minute (gpm) acidic water
Continuous Mechanical Froth Flotation Cell
Table of ContentsDynamic Mathematical ModelsExperimental Features and Preliminary ResultsResults The BSA and DRC models have been shown to offer excellent alternatives to the NDRC model, given previously in the literature (1) in predicting the dynamics of glass bead flotation. Since the TP model converged to unrealistic parameter values and gave the poorest data fit, the TP model is judged unacceptable
Coarse Grinding in a Ball Mill
Table of ContentsPractical ConsiderationsCostsTheoretical Considerations Rod mills were developed as a logical substitute for the rolls crusher when larger tonnages had to be handled, on a continuous basis. Today, with even larger tonnages to process, the trend is to install larger equipment, automate the plant and develop the highest availability possible, in order to cut costs. The rod mills, because
Chemiluminescence Detector
Table of ContentsChemiluminescence DetectorEffect of Instrument Parameters on ResponseEffect of PMT Anode VoltageEffects of Reactor Pressure and Flow Rates of Ethylene and SampleResponse CharacteristicsInterference EffectsComparison of Chemiluminescence-Detector, KI, and Mast Methods in Measuring Ozone in Smog-Chamber AtmospheresDiscussion Instruments currently in use for routine measurement of ozone in the atmosphere are based on ultraviolet spectrometry, coulometry, or colorimetry. Studies have shown
Basic Control Strategy for Mineral Processing
Table of ContentsControl TechniquesStandard Grinding Circuit with Cyclone ClassifiersReversed Circuit with Cyclone ClassifiersIdealized Control System for Flotation Cells The principle purpose of applying control to any process is to improve its profitability. Even when considering the impact of a plant on its surrounding ecology this is still true, since the sanctions felt most immediately from violations of the regulations are
Bacteria & Hydrogeochemical Prospecting
Action of certain strains of bacteria has been implicated as a significant factor in the oxidation of ore deposits. Other bacteria are thought to be significant in the formation of syngenetic sedimentary ores and in supergene enrichment processes. A normal soil/ground-water regime provides all of the necessary pH and Eh conditions for several groups of bacteria which influence the sulfur
Advantage of a Crowd for Acid Waste Liquors
Because of increased pressure from Federal & State Regulatory-Agencies, most acid flows will require some sort of treatment prior to being discharged to receiving streams. In many industries, the volumes of liquors are large and their acid content varied. “Standard” methods of acid neutralization with lime have been known for years, however, the volume and characteristics of the resultant precipitated
Synthetic Zeolites Properties and Applications
Table of ContentsZeolite Structural ChemistrySome Aspects of Zeolite ChemistrySynthesis of ZeolitesApplication of Synthetic Zeolites as Molecular Sieves Zeolites were first recognized as a new group of minerals by Cronstedt with the discovery of stilbite in 1756. The word zeolite was coined from the two Greek words meaning “to boil” and “a stone” because of the loss of water when heated
Shaft Kiln for Lime Production
New is a relative term, and when used with reference to a concept as old as shaft kilns can be applied to a number of designs. In this case the design that is the subject of this paper, is known as the ring or annular shaft kiln as developed by Mr. Karl Beckenbach of West Germany. It is a single
Semi-Autogenous Liners
The never ending search for lower unit costs led Pima Mining Company’s management to study various alternatives shortly after Expansion III was completed. It soon became apparent that a considerable amount of ore assaying 0.35% copper had to be moved in order to maintain mill feed at the desired 0.54% copper content. New Mill Flowsheet A completely new and separate