Blogs
Heap Leaching of Uranium
Table of ContentsPilot Test ProgramFull-Scale Pilot Heap OperationMaybell Heap Leach Experience Union Carbide began looking seriously at heap leaching in 1971- At that time some 1.6 million tons of mineral averaging 0.040% U3O8 were stockpiled at various sites around the Gas Hills, Wyoming, uranium facility. Several alternatives for economically exploiting these reserves were considered and heap leaching seemed the most
Grinding Circuit Control
Table of ContentsOld Mill FlowsheetNew Mill FlowsheetDuval Grinding Circuit ControlA Review of Automated Grinding Control Systems Grinding Circuit Description Cyprus Pima has two concentrators, one with a conventional crushing-grinding circuit and the other using semiautogenous grinding followed by ball mills. Old Mill Flowsheet The original mill was constructed in 1956 but has been expanded three times so that by 1967 there
Grate-Kiln Operations for Better Pellet Quality
Table of ContentsOperating/Maintenance Cost SavingsEnergy RequirementsImproved Pellet QualityEnvironmental Standards This paper describes some of the latest improvements that have been incorporated or planned by the Cleveland-Cliffs Iron Company to reduce operating costs and improve pellet quality. The Cleveland-Cliffs Iron Company operates and manages mining, beneficiation, and pelletizing operations in Michigan, Canada, and Western Australia. Operating/Maintenance Cost Savings Cleveland-Cliffs Iron Company,
Gearless Ball Mill Operation
Table of ContentsStructural Design of Mill and BearingsStructural Design of the BearingOperational ResultsMaintenance of “Gearless Drive” Mill The reliability of large diameter, high horsepower ball mill is paramount when large production and minimum downtime is required. The 17 ft. x 56 ft. double compartment ball mill at St. Lawrence Cement Company has the first gearless drive built in North America and
Topaz Flotation
Table of ContentsBeneficiation StudiesFatty Acid FlotationPetroleum Sulfonate FlotationAmine FlotationDefluorinationConclusions and Discussion Samples of a topaz-bearing gneiss from Jefferson County, Colorado, and a topaz-bearing schist from Chesterfield County, South Carolina, were obtained for the investigation. These are the areas outlined by USGS as containing probable commercial quantities of topaz. Partial chemical analyses of the samples are shown in table 1. Mineralogical
Flotation of Insoluble Slimes from Potash Ore
Filtration of the insoluble slimes flotation concentrates recovered 87 to 90 percent of the brine. Flotation concentrate filtration rates were 7 times faster than the filtration rates of mechanically deslimed products. Potash losses in the deslime product and process brine requirements increase as the insol content increases. Therefore, improved methods to remove inso lslimes are needed that will (1) reduce
Feldspar Flotation using Non-Hydrofluoric Acid System
The response of feldspar flotation to tallow diamine dioleate collector in the presence of sulfuric acid is studied using, batch flotation experiments. Application of this non- hydrofluoric acid (non-HF) reagent system in the flotation of mineralogically and chemically different feldspar ores is compared with that of the conventional hydrofluoric acid system. The dependence of flotation recovery and concentrate grade on
Extraction of Nickel and Cobalt from Acidic Solutions
LIX63 in combination with DNNS selectively extracts nickel and/or cobalt from acidic leach liquors with pH values as low as 1.0. Nickel/cobalt and cobalt/nickel selectivities are achieved by varying the relative concentrations of LIX63 and DNNS. Increasing LIX63 concentration retards both extraction and stripping rates while DNNS has the opposite effect. Slope analyses of equilibrium data indicate that both LIX63
Tar Sands Bitumen Extraction by a Hot Water Digestion Flotation
Tar sand deposits in the State of Utah contain more than 25 billion barrels of in-place bitumen. Although thirty times smaller than the well-known Athabasca tar sands, Utah tar sands do represent a significant domestic energy resource comparable to the national crude oil reserves (31.3 billion barrels). The term “tar sand” refers to a consolidated mixture of bitumen and sand.
Effect of Abandoned Lead and Zinc Mines and Tailings Piles on Water Quality
Table of ContentsGround WaterTailings Area RunoffEffects On Streams Dissolved zinc concentrations averaged 9,400 µg/L (micrograms per liter) in water from abandoned lead and zinc mines, some of which discharge at the surface. Contamination of the shallow aquifer by the highly mineralized mine water is limited to the immediate mining area. The quality of water in the deep aquifer is generally
The Effect of Hydrogen Peroxide on Leach Dump Bacteria
Table of ContentsExperimentalThe OrganismsAssaysCulturing MethodsH2O2Test MethodsResultsManometry ExperimentsGrowth StudiesH2O2 in Simulated Leach SystemDiscussionAcknowledgements In recent years, hydrometallurgical processes for recovery of metal values from low-grade ore minerals have played an increasingly important role. Dump leaching of low-grade copper waste materials in the western United States now yields 11.5% of the total U. S. copper production. Although scavenger operations in uranium leaching
Open Pit Design Economics
Table of ContentsCut-Off GradeStripping RatioSlope AngleModel for Selecting the Range of Slope Angle The economic limit of an open pit mining operation is dictated by three basic elements- cut-off grade, stripping ratio and slope angle. Although these elements are interrelated, they are functions of a number of independent parameters, which are too numerous to list completely. Simply stated, the following
Ball Mill Charge Control
Direct control of ball mill inventory has been the goal of a number of investigators over many years. To put some numbers on these concepts consider a 250 ton mill with 3 nominal 10 ton inventory that should be controlled to one part in forty that is a 2.5% band or ¼ ton. This will require a weight resolution of ±0.05%. Fortunately,
Earth Bottom Thickener Design & Construction
The essential elements of thickener basin construction consist of: Laboratory testing and selection of soil materials for thickener bottom and determination of required thickness of treated blanket. Rough grading of site to bottom slopes of thickener basin. If imported soil materials are to be used, establish rough grade at bottom slopes minus 150 to 450 mm to allow for placement
Bauxite Crushing & Phosphate Rock Processing
Three Reversible Impactors are located at the Piney Point Plant, Palmetto, Florida. This plant is part of the Davison Chemical Division of Borden Chemical Co. These machines reduce diammonium phosphate or granular triple superphosphate (GTSP) from a feed of 75 x 3.35mm (3″ x 6 mesh) to an 852-952 minus 3.35mm (6 mesh) product. Capacity is 41 TPH (45 STPH)
Froth Level & Pulp Density Control
The possibility of increasing the efficiency of mineral processing plants by means of computer control has prompted metallurgists to examine their flowsheets more critically in order to develop practical control strategies. Control schemes in use to date generally rely on the automation of traditional and previously manually regulated control loops, for instance the addition of reagents to maintain a constant
Crushing Circuit Process Control
As indicated in the introduction to this paper, it is a sequel to that which i gave to the last annual meeting in Atlanta in march, this paper goes further into aspects of crushing and screening, primarily from the standpoint of circuit control. By proper control over the use of crushing energy, we will be able to produce finished products from
Flotation Plant Process Control & Automation
Table of ContentsCollectorFrotherDepressantFroth Height The variables involved in a complex process like flotation can be classified as follows: a. Disturbance variables – which are undesired properties of the process input which affect the value of the process output but which are not subject to adjustment. They are the result of changes in the properties of the feed, like changes in
Vacuum Filters for Dewatering
Table of ContentsThe Pelletizing Process Development and First Generation FiltersProcess Optimization and Second Generation FiltersSteam Drying and Third Generation FiltersHigh Performance for Fourth Generation FiltersFilter Hydraulic Studies The pelletizing process for low grade iron ores has undergone continual changes since its inception over twenty years ago. These changes have necessitated filtration equipment changes in order to produce a product suitable
Thickener Selection Parameters
Table of ContentsFeed WellsRakesTank Areas A bewildering number of continuous thickeners and clarifiers are used in mineral industries and other heavy industries. General types are: Conventional Thickeners Thickeners with Flocculating Feedwells Solids Contactors Tray Thickeners Lamellas Conventional Thickeners with Lamellas High Flow, Fluid Bed Thickeners These units must be adapted to varied applications. They must provide operating flexibility to meet
Two Stage SAG Grinding Circuits VS ABC Circuits
Grinding facilities are arranged either as single-stage circuits, or in a two-stage configuration with ball mills. Another major concentrator, designed with an autogenous mill, ball mill, crusher (ABC circuit), is presently under construction and scheduled for start-up late this year. The host rock of the Island Copper deposit is a highly fractured fine-grained andesite. A prominent alteration product of this
How to Recover Cobalt and Nickel from Copper
Table of ContentsLaboratory InvestigationsDescription of MaterialGrindingMagnetic Properties and Separation PotentialLeachingOther Preliminary TreatmentsFlotation of ChalcopyriteLarge-Scale Demonstration TestsConclusions It is the goal of the Bureau of Mines to help maintain an adequate supply of minerals to meet national economic and strategic needs. Among the activities designed to attain this goal is that of advancing minerals technology by making improvements in metals and
Coal Washing by Jigs
The Greenwich Collieries Co. is a subsidiary of the Pennsylvania Mines Corporation, and a wholly owned subsidiary of the PP&L Co. which serves the northeastern portion of Pa. PP&L annually consumes about 11 million tons of coal per year and is the largest consumer of both bituminous and anthracite coal on the eastern seaboard. Sulphur content of Greenwich coals are
Coal Fired Lime Kilns
The combustion of pulverized coal is a century-old practice. Many people have investigated coal dust and the residual fly ash particles that remain after combustion. But the combustion process and fly ash formation mechanism are not understood. Working at our Maysville, Kentucky lime plant, the Dravo Lime Company Research team has collected samples of partially burned coal dust from the