Blogs
Heap Leaching of Gold Ores in Northeastern Nevada
Table of ContentsTechnical and Economic Considerations of Heap LeachingPast Applications of Vat Leaching in the AreaRequirements for the Heap Leaching ProcessResults of Heap Leaching Tests on Ores from the RegionConclusions and Discussion of Heap Leaching tests.Planning for Proper Application of Heap Leaching Heap leaching shows promise of being an attractive method for treating large tonnages of oxidized gold ores from
Gross-Count Method of Microscopic Quantification
Table of ContentsSample PreparationAdvantages and Limitations of Point-CountingConcepts of Gross-Counting Microscopic evaluation of trace quantities of metalliferous phases in flotation products requires counting large numbers of particles. Particle counts of many thousands may be required for precision, but not “obtained practically by conventional microscopic techniques. A less tedious microscopic method for evaluating trace sulfides in mill tailings was developed for
How much Gold in Sea Water
Table of ContentsThe Trend of Gold Determinations in Sea WaterSolubility of Metallic Gold in Sea WaterAnalysis of Gold in Sea WaterOutlook for Gold from Sea WaterSummary Interest in the recovery of minerals from sea water has been stimulated in recent years by proposals for large-scale water desalination plants that would yield both fresh water and enriched brine. Extraction of selected
Functional Mineral Pigments
Table of ContentsKaolinGround Calcium CarbonateTalcDiatomiteMica Functional mineral pigments are used in large quantities in paint, paper, plastics, rubber, textiles, agriculture, and several other industries. Originally extender pigments were employed only to lower cost. They were thought of merely as adulterants to replace more expensive prime pigments and binders. However, over the years their role has become better understood, and today
Dragscraper for Stockpiling, Reclaiming and Blending
Today more than ever, there is an increased demand for higher plant production capacities and efficiencies to offset the increasing costs for labor and materials. Plants involved in processing large volumes of bulk materials are particularly interested in more efficient material handling systems to (1) reduce labor and maintenance costs, (2) improve blending of non-uniform raw material feed to processing
Crushing & Grinding of Gypsum
In the crushing and grinding of metallics for beneficiation, the sizing is normally done to liberate the metals or sulphides for further processing to improve recoveries of the basic metals or minerals. The objective is to reduce the ore in size through various closely controlled stages to that degree of fineness which gives an economic liberation of valuable mineral, but
Automatic Control of Crushing and Grinding Facilities
Table of ContentsPrimary CrushingGrinding Control During the past two years, there has been an increasing acceptance of process automation among ferrous, non-ferrous and non-metallic rock processing operations in an attempt to keep total unit costs in line in a market situation where labor and material costs are rising almost daily. The experienced crusher or mill designer and operator should know
Beneficiation of Kaolinite Clay from Silica Sand Washings
Silica sand has been mined in Illinois from the St. Peter Sandstone since the turn of the century, especially in the area around Ottawa on the Illinois River in the north-central part of the state. Production of this sand, consumed mainly by the glass and foundry industries but also sought after for many other uses, has grown with the economy.
Wet Autogenous Grinding in Tumbling Mills
Table of ContentsAutogenous Grinding MechanismsOperational Aspects The autogenous grinding method has been progressively employed in mineral dressing plants during the last 15 years. The term has been used with somewhat different meanings. In this paper the author will use it in the most restricted way, for processes where run-of-mine ore (rock) in one step is reduced to a grind product
Water in Fluorspar Flotation
Water has received little attention as a variable in flotation, even though it is a known fact that water hardness often has an adverse effect on purity and recovery, particularly on the flotation of non-metallic minerals. Because of this fact, process water used in some flotation plants is treated to reduce hardness to an acceptable level. In the laboratory, distilled
Chrysocolla Sulfidization and Flotation
Studies of sulfidization and flotation of chrysocolla involving the use of pH and sulfide ion instruments, a Zeta meter, microflotation techniques, and sensitive determinations of adsorbed sulfur have given new insight into the mechanism of the process. Factors that affect the recovery of sulfidized chrysocolla by flotation appear to be the pH at which it is sulfidized, and certain alterations
Smelting of Military Electronic Scrap
Table of ContentsNature of Military Electronic ScrapSmelting StudiesSmelting High Aluminum Electronic ScrapSmelting Low Aluminum ScrapOxidation Smelting and Electrorefining of Low-Aluminum ScrapOxidation SmeltingElectrolytic RefiningPlans For Future WorkSummary Gold, silver, and platinum group metals are widely used in electronic and electrical components to provide long-term reliability, Construction of military equipment consumes the largest proportion of the precious metals used in the electronic
Parallel HydroCyclone Simulation
Table of ContentsDescription of a CircuitLynch Model of a CycloneComputational Procedure to Obtain Constants for Cyclone Model In order to simulate a grinding circuit, it is necessary to obtain valid mathematical models of the grinding mills and classifiers in the circuit. Several models of grinding mills have been proposed and models of cyclone classifiers are available. Description of a Circuit
How to Refine Copper Cement
Table of ContentsCement Copper SamplesCopper Powder ProcessFlotation of Cement CopperChemical Purification of Flotation ConcentrateReduction, Sintering and GrindingElectrorefining of Sintered AnodesCost EvaluationConclusions Cement copper production in the United States has increased during the past few years, principally because more submill-grade material from open-pit operations is being leached in waste dumps. Since 1960, the cement copper annual growth rate has been about
How to Recover Elemental Sulfur from Ores by Solvent Extraction
Table of ContentsPractical Aspects of Solvent ExtractionPilot Plant Study of a Solvent Extraction Process Considerable amounts of the world’s known reserves of elemental sulfur are found near the surface in areas of volcanic activity both active and inactive. Because such deposits cannot in general be mined by the well-known Frasch process, and because other methods of recovery have not proven
Multi-Stage Flash Evaporation System for the Purification of Acid Mine Drainage
Table of ContentsMine Drainage Abatement ProgramAMD Processing for Potable UseAMD Treatment by Multi-Stage Flash EvaporationAMD Evaporator Demonstration Plant In January of 1964, the Board commenced a vigorous program using appropriated funds and funds donated by the coal industry to finance a research program devoted to seeking solutions to the mine drainage problem. A review of published literature on the treatment
Mine Ventilation
Table of ContentsPlanningLeakagePresent Ventilation The language concerning ventilation in many sections of the Act could very well deprive or limit the mining engineer in planning the ventilation for new mines, since the Act requires federal approval of all ventilation plans. Dependent upon approval and of course application of the law, this could, due to economics, prohibit the opening of new
Microbiological Leaching
Table of ContentsResearch to DateBacterial NutrientsCurrent Leaching Results Bacterial attack of sulfide minerals has been going on for centuries but only recently was it discovered that the acid and iron often found in coal mine drainage is produced by bacterial action on the iron sulfides in the coals. Not until 1950 was it proven that bacteria were playing a role
Method of Evaluating Magnetic Separator Force Patterns
One of the problems facing both the designer and the user of magnetic separators is the evaluation of the body forces acting on particles in the magnetic field of the separator. Perhaps the most elegant method of evaluating the body force associated with a drum-type magnetic separator. Once the coefficients of the series are known, it is then possible to
LIX-64N A Progress Report on the Liquid Ion Exchange
Table of ContentsChemistry of LIX-64NLaboratory InvestigationsPhysical Characteristics of LIX-64 and LIX-64N In late 1965 General Mills announced the availability of a new liquid ion exchange reagent LIX-64, for the recovery of copper from various solutions, such as dump leach liquors. Acceptance of this material by the copper industry has been gratifying. A number of pilot plants have been operated, and
Limestone Treatment of Acid Mine Drainage
Table of ContentsNeutralization ProcessChemical Properties of LimestonePhysical Properties of LimestoneLimestone SelectionLimestone Treatment SystemsLow Iron AMDFerric Iron AMDFerrous Iron AMDLimestone – Lime TreatmentConclusions The occurrence of acid mine drainage (AMD) with coal mining has been well documented. Less documentation is available of its association with other types of mining, e.g., copper, gold, zinc, and sulfur. Yet there are many locations in
Impermeable Dump Leaching Chemistry
Table of ContentsExperimental ProcedureExperimental DataDiscussion of Experimental ResultsInterpretation of DataConclusionsAcknowledgmentsLeaching Tests on “J” Dump Core SamplesDescriptions of SamplesLaboratory Percolation Leaching TestsConclusions A series of tests were run on fresh Becker drill samples from a drill hole in Kennecott’s Chino “J” dump, near Silver City, New Mexico, to obtain data on the leaching chemistry of a relatively impermeable sulfide copper waste
Selection of a Leach Dump Test Area
Leaching of waste material at Kennecott’s Chino Mines Division at Santa Rita, New Mexico, has been accompanied by increasing difficulty in circulating leach solutions through the dumps. As a means of recognizing existing problems and considering alternative applications of the leaching concept, a leaching research program was proposed which could be applied to a specific, typical waste dump. Conclusions derived
Laboratory Extraction of Copper by Roasting and Smelting
Table of ContentsDesulfurizationMetallization of Oxidized PelletsCopper SmeltingCopper RefiningConclusion In a broad sense, sulfide copper pyrometallurgy is a batch sequence in three separate vessels, i.e., reverberatory furnace to yield “matte copper,” a converter to produce “blister copper,” and another reverberatory furnace to produce fire-refined copper. Matte smelting is relatively unchanged since it became universal practice some 50 to 60 years ago.