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By J. K. Grunig

A process consisting of leach, continuous countercurrent decantation, resin-in-column ion exchange, evaporative crystallization of beryllium sulfate, and decomposition of the sulfate was developed for Spor Mountain, Utah, ores. The process is metallurgically sound, has a minimum of process steps, and is applicable to a wide variety of beryllium ores. The most novel aspect of the process is a resin system of ion exchange which is highly selective for beryllium and which rejects substantially all impurities except for minor amounts of aluminum, magnesium, fluorine, and sulfate in addition to beryllium. The oxide from sulfate decomposition meets specifications of potential users.

Jan 1, 1982

By S. Behl

A major limitation in developing successful selective flocculation schemes is the difficulty encountered in adsorbing the polymeric flocculant only on the desired substrate. In this paper a correlation between selectivity of flocculant adsorption and separation efficiency is outlined and a potential technique to achieve selective adsorption of flocculants is discussed.

Jan 1, 1992

By Ray E. Williamson

One of the prime objectives of the mine industry is to develop a low cost way to clean up what has been called "The Rape Of Mother Nature". The project falls under the broad umbrella of reclamation, which is now considered an essential part of the mining cycle. As such, it is being given full consideration in the initial planning of all surface operations. In most areas, if a proposed mining system does not lend itself to proper reclamation, it is not an acceptable system. By combining mining and reclamation plans, a producer not only can minimize reclamation costs, but can also restore the land to usefulness and insure continuing profits after a deposit is depleted. As long as fifteen years ago, many of the larger mining companies were already deeply involved in this extra cost work. Even then the involved companies were projecting a great need for a bigger bulldozer, Bigger than anything commercially available. At that time, the D9 tractor weighed about 60,000# bare weight.

Jan 1, 1975

By S. A. McGhee

ASARCO Incorporated embarked on a modernization and expansion program to improve overall operating efficiencies and to more effectively develop the large mineral reserve at the Ray Complex Open-Pit Mining operation located near Kearny, Arizona. Major elements of this Ray Modernization and Concentrator Expansion Project included engineering and construction of a 54,400 MTPD (60,000 STPD) In-Pit Crusher and Overland Conveying System. and a 24,200 MTPD (30,000 STPD) Copper SAG Concentrator and Tailings Disposal System. Detailed engineering, procurement, and construction management were initiated in November 1989 under contract with Bechtel Corporation. Field construction commenced in May 1990 leading to mechanical completion and start-up during February 1992.

Jan 1, 1993

By R. L. Grayson

Compliance standards for respirable dust which are reduced because of high quartz concentrations have become an industry-wide problem. Research on the physical and chemical character of quartz-classified particles in respirable coal mine dusts indicates that they may exist in intermixed layers or may be coated by clay or coal material. The relative amount of intermixing varies with the coal seam being mined. If most of the quartz particles of a mine dust are "pure," then the dust may have a high fibrogenic risk potential because of truly free silica and the compliance standard should be lowered. If, however, the quartz is locked inside another material matrix, or coated, a reduced compliance standard may not be appropriate.

Jan 1, 1990

By Drummond Earley III

The hydrology of in situ leach mining operations is being studied by the U.S. Bureau of Mines using a variety of techniques, and the Bureau has made significant advances in tracking and modeling the flow of leach solutions in rock formations. However, the influence that leach solution composition has on the hydrology of these systems is poorly understood, and geochemically-controlled changes in the hydrologic characteristic of ore deposits during in situ leach mining of porphyry-hosted, copper oxide ores have not been previously studied. The Cyprus Casa Grande in situ leach mining operation mines fracture-hosted and disseminated copper oxides (predominantly chrysocolla) hosted by granodiorite porphyry using a pattern of underground wells. The injection solution consists of sulfuric acid raffinate from a solvent extraction-electrowinning plant. Chemical analysis of representative injection and recovery solutions reveals that gangue cation concentrations in these solutions are high, and geochemical modeling shows that the solutions are saturated or nearly saturated with respect to gypsum, jarosite, and various amorphous oxides. Precipitation of these solids is evoked by calcium-exchange reactions, rising pH, and perhaps locally rising redox potential, as the leach solution reacts with the ore minerals, host rocks, and the atmosphere. Mass and volume balance calculations show that approximately 25 cm of precipitates are formed per gram of copper recovered at Cyprus Casa Grande. The results of geochemical modeling agree with petrologic examination of pre-and post-leach core samples from the leached horizon. Moreover, hydrochemical modeling and hydrologic field data suggests that chemical precipitation causes significant decreases in porosity and permeability during in situ leach mining of porphyry-hosted, copper oxide ore.

Jan 1, 1992

By Koichi Nishimura

Japan's coal reserves are estimated at 8,583 million tons (according to the materials on X World Energy Conference,. 1976). Japan is a long island country in the shape of an elongated cashew nut whose top is pointing to the north and its lower tip is pointing to the west. And her major coal fields are located in the two extreme far parts of Hokkaido in the north and Kyushu in the south. On the other hand, Japan's major industrial center are located in the central part of the country far from either coal-producing areas. This fact places coal a great geographical disadvantage in comparison with petroleum whose refining bases are concentrated on the coastal regions virtually next to major industrial centers.

Jan 1, 1982

By James E. Myers

This study is a survey of the current "state-of-the-art" of commercially-available sonar tools to monitor the true shape of man-made cavities within the Hutchinson Salt of south-central Kansas. The work entailed ferreting out the available information, most of which is proprietary in nature; then examining actual existing conditions and arriving at a reasonable scientific evaluation of the method. Our studies were confined to one LPG field and two brine well operations in south-central Kansas. No field testing of any devices was performed, only questioning user firms, and studying cores, logs, and sonar surveys graciously made available by the companies we have contacted. Since these data are still somewhat proprietary, the company participants have asked that their company names be omitted from this presentation.

Jan 1, 1973

By Langtry E. Lynd

The titanium industry is based on the unique properties of titanium dioxide and titanium metal. Because of its whiteness, high refractive index and resulting light scattering ability, titanium dioxide in its two main allotropic forms, rutile and anatase, is the predominant white pigment for paints, paper, plastics, rubber, and various other materials. Titanium metal, because of its high strength/weight ratio and resistance to corrosion, is widely used for aircraft, both in airframes and engines, for powerplant surface condensers, and a wide variety of chemical processing and handling equipment. U.S. production of titanium dioxide pigment in 1979 was about 658,000 tons - 2/, valued at about $770 million. Net shipments of titanium mill products were around 19,000 tons, worth about $380 million. These two major uses account for over 96% of domestic titanium consumption. The third largest application, the use of rutile for coating welding rods, required about 9,500 tons of rutile concentrate, worth about $4 million. Other applications of titanium-bearing raw materials include the manufacture of titanium carbides, ceramics, and chemicals, and the recently developed use of ilmenite as a substitute for barite in well-drilling muds.

Jan 1, 1980

By J. W. Hawkins, K. B. C. Brady, M. W. Smith

The Pennsylvania Department of Environmental Protection (PaDEP) has been issuing surface mining permits since 1984 that authorize remining in areas that will affect preexisting pollutional discharges. These permits require the mine operator to employ best management practices to reduce pollution loading from abandoned mine discharges. A total of 110 completed mining operations with 233 discharges were evaluated to determine the impact to water quality. Overall, acid loading from these discharges was reduced by 7, 200 kg (15, 900 lbs) per day or 61%. Metal loadings were also reduced. For acidity, 49% of discharges improved or were eliminated, 52% showed no significant change and fewer than 1 % got worse. Loading reductions resulted from a combination of reduced concentrations and lower flows.

Jan 1, 2003

By F. Ansheng

Though it becomes increasingly important with the valuable minerals in their deposits tending to be fine and poor, the solid and liquid separation remains difficult especially when the particles are of micrometer size and of low density. Almost of all conventional thickeners result in that fine particles lose into overflows which often costitutes a loss of potentially valuable resources as well as an environmental hazard. The addition of flocculations may improve the settling of solids but may also not work well for the final removal of fine particles from the overflows (Ref.1).

Jan 1, 1990

Coal waste materials inhibit direct vegetation establishment due to adverse physical and chemical properties, particularly low water retention and high potential acidity. The Moss # I coal refuse pile is located in Dickenson County, Virginia, and was idled in the late 1980&apos;s with little topsoil resource available for final closure. The refuse was acidic (Total-S = .. 38%; pH = 3.6), black, high (70%) in coarse fragments, and had a low water holding capacity (4.5% in < 2.0 mm fraction). A small plot experiment was established on the refuse pile to evaluate the influence of liming rates (50% and 100% of lime req.) and topsoil thickness (15, 30 and 60 cm) on vegetative growth and leachate quality. Liming and topsoil amendment increased the surface soil pH from < 4.0 to > 6.0 over a two-year period, which resulted in greater vegetative cover and biomass than the control plots. All topsoil treatments resulted in greater vegetative cover and biomass than plots treated with lime only due to improved surface soil physical and chemical properties. A topsoil treatment of 60 cm gave the thickest vegetative cover and biomass yield. Such a treatment, however, would be cost-prohibitive at this location. Application of 27 Mg ha-1 of lime to the refuse surface along with 15 cm of topsoil produced acceptable two-year vegetative cover and biomass, and appeared to be the optimal treatment for this particular situation. Both liming and topsoil had no affect on leachate pH and the electrical conductivity in leachates collected below the plots. This suggests that surface revegetation will have little effect on the quality of water draining through the pile, so long term water treatment requirements may not be reduced by successfully revegetating the pile surface.

Jan 1, 1999

By Barry D. Simmons

The Millenbach copper-zinc orebody is an ideal Canadian example of a stratabound base metal deposit in volcanic rocks. The mine, operated by Lake Dufault Divison, Falconbridge Copper Ltd. is located five miles north of the city of Noranda in northwestern Quebec. The deposit occurs within an Archean volcanic sequence which forms part of regional acidic volcanic center within the Abitibi greenstone belt. Preproduction ore reserves totalled 2,075,000 tons grading 3.5% copper, 3.6% zinc, 1.1 ounces per ton silver, and 0.02 ounces per ton gold. Stratabound lenses of massive sulphides together with underlying stringer sulphides are closely associated with a dome of quartz-feldspar porphyritic rhyolite approximately 3000 feet below surface. The paper describes the presently known geology of the deposit and includes documentation of sulphide mineralogy and textures as well as sulphide/ host rock relationships. The stratigraphy, petrography and chemistry of the volcanic host rocks are described with emphasis on the alteration intimately associated with the sulphide bodies. Although the volcanic stratigraphy is complex within the mine area, the presence of only low-grade metamorphism and the relative lack of structural deformation allow detailed interpretation of geological history. Presently recognized evidence strongly suggests that the sulphides were deposited at and near sea-floor, by hydrothermal solutions. The dome of porphyritic rhyolite appears to have been the most significant factor controlling sulphide localization.

Jan 1, 1975

By Robert A. Cummings

A field inventory was made of the mineral, geologic, geothermal, and groundwater resources of three geologically recent lava fields in the desert of Oregon. The term "resource" was applied with care: a "resource" must have particular value or worth, although it need not be economically viable. The spectacular volcanic features of the area have particular scientific and general interest and thus constitute geologic resources. The mineral endowment, mostly occurrences of low unit value such as stone and cinders, in large part are not resources, due to market conditions, regulations, and other factors. These and other conclusions will be used by the Bureau of Land Management in its multiple land use planning process for the area.

Jan 1, 1980

By H. Sis

The pressure filtration behavior of dispersed and flocculated alumina slurries at high percent loadings is discussed with an objective to determine the effect of surfactant type and concentration on slurry properties. A high purity alumina powder was used as a model solid. Dispersion of the alumina was controlled by surfactants that are considered to act by electric and steric stabilizers. The effect of both the ionic and nonionic surfactants was investigated. Surface charge measurements of the slurries were carried out by electrokinetic sonic amplitude (ESA) method to understand the mechanisms. The effect of surfactant type and concentration on the kinetics of pressure filtration and final cake properties are discussed.

Jan 1, 1998

By W. M. Cross

Optical fibers have revolutionized the telecommunication industry, because of their ability to transmit large amounts of data over long distances. Without optical fibers many of the communication technologies on which business, industry and research rely would be impossible. In addition to their use as communication devices, optical fibers are often used as sensors. Despite the great promise that optical fibers have for the development of many types of remote sensing devices, few remote sensing devices have been built for use in the mineral industries. This paper will describe the use of optical fibers as sensors for surfactant adsorption at mineral surfaces.

Jan 1, 1995

By Vincent A. Scovazzo

During the winter months of late 1985 and early 1986, residents along Dry Fork near Grundy, Virginia (United States) experienced seismic events that they attributed to longwall mining at Island Creek Corporation’s (Island Creek) Virginia Pocahontas Mine No. 3 (VP-3 mine). Island Creek contacted STS D’Appolonia Ltd. (STSDL) on March 7, 1986, to investigate these events. An STSDL representative, Vincent Scovazzo, interviewed residents of Dry Fork on March 10, 1986. It was noted that only people within a residential structure felt the events they described as house shaking, vibrating walls, and ceramics falling from shelves. STSDL representative installed a blast monitor at a residence. Within 2 days, various events were recorded. Some could be attributed to truck and heavy equipment movement. Eight events had no obvious cause but appeared on resident’s written logs as earthquakes caused by mining. STSDL contacted Utah Geophysical, Inc. who had developed a technique to determine the mode of rock failure using the seismic record. Utah Geophysical was engaged to install and monitor a microseismic network, locate the epicenter of the events, and work with STSDL in determining modes of failure. The network was comprised of six geophones located at five stations. Data was recorded for 24 days from May 20 through June 13, 1986. The data was filtered to eliminate events determined to have an origin other than the longwall panels’ overburden and under-burden. The larger events from this filtered data set were selected and analyzed to determine their hypocenter locations, time of occurrence, magnitudes, and failure mode. Processed data was interpreted, tabulated, and plotted by STSDL to provide information relative to the sources of the seismic vibrations and their possible relationship to the mining operation.

Jul 1, 2023

By P. James

"INTRODUCTION Dissolved salts build up in leach solutions over time as leach solutions mature. Iron can be particularly problematic for hydrometallurgical copper production as it can compete with copper for separation during solvent extraction (SX), leading to iron bleed through and reduced electrowinning (EW) efficiency. In its ferric form (Fe+3) it precipitates as a hydroxide at fairly low pH and can promote clogging and disrupted flow within leach pads as a result of localized pH deviations – such as might result from weather events. The solids formed can cause relatively irreversible degradation to pad productivity. The precipitation pH point for solids formation falls as the ferric (Fe+3) concentration increases, making the issue more prevalent as leach circuits for ore bodies containing appreciable iron get older. It can also be more of a concern when leaching lower grade ore like tailings where lower copper content may increase iron/copper ratios which may increase iron accumulation rates. The precipitation pH point for solids formation falls as the ferric (Fe+3) concentration increases, making the issue more prevalent as leach circuits for ore bodies containing appreciable iron get older. It can also be more of a concern when leaching lower grade ore like tailings where lower copper content may increase iron/copper ratios which may increase iron accumulation rates. Control of ferric (Fe+3) levels could be used to lower ferric (Fe+3) levels and keep the ferric hydroxide [Fe(OH)3] precipitation pH sufficiently high to avoid the associated solids formation and potential leach pad occlusion. Control of ferric (Fe+3) and ferrous (Fe+2) tenors and ratios may also provide benefit for improving sulfide ore leaching or bioleaching performance and effectiveness. Traditionally options for such control were rather limited with bleeding contaminants off or chemical dosing treatments being prominent methods. Now Blue Planet Strategies introduces a new option. Blue Planet Strategies (BPS) focuses on improved resource utilization targeting electrolytic treatment and waste conversion into resources and has now demonstrated that its proprietary DeMet™ (Dynamic Electrolytic Metal Effluent Treatment) platform is highly effective at efficient low-cost conversion and control of iron content in leach streams in addition to targeted dilute metal recovery.[1-6] This powerful new capability provides a new treatment opportunity to control leach solution ferric (Fe+3) and ferrous (Fe+2) tenors to enhance leach operation production."

Jan 1, 2015

By James P. Connell

The Berkeley Pit of The Anaconda Company is located on the southeast slope of the Butte Hill, the legendary "Richest Hill on Earth," and is one of the largest pit operations in the world completely dependent on truck haulage. Through October 31, 1968, the Berkeley stripping and mining operations have moved more than 442,589,000 tons of material. Present scheduled production is at the rate of 260,000 tons per day, with a record quantity of 306,900 tons having been hauled on September 23, 1968. Although the Berkeley Pit has been in production only a little more than ten years, it has been the proving ground for many of the presently used large trucks. Beginning with the original R. G. LeTourneau 75-ton electric truck in 1960, Unit Rig 85- and 100-ton electric drives, Haulpak 65- and 105-ton electric drives, and Caterpillar 100-ton electric drives have all been tested under production conditions. In addition, engine development has kept pace with both 1000-hp diesel and 1100-hp gas turbine engines now under test. As the size of the Berkeley operation has grown, the truck fleet has changed in size and appearance in order to maintain economic mining costs. The original fleet consisted of forty-three 36-ton trucks with conventional mechanical drives. The present fleet is made up of eighty-nine trucks: nineteen 85-ton Unit Rig electrics with 700-hp diesel engines; sixty-nine 100-ton Unit Rig electrics with either 700- or 1000-hp diesel engines; and one 100-ton Unit Rig electric with an 1100-hp gas turbine engine.

Jan 1, 1969

By D. A. Norrgran, J. A. Wernham

Introduction In view of the continuing depletion of natural resources, requirements for energy conservation, plant optimization and hazardous waste management, and environmental consciousness, recycling and secondary recovery of materials are being developed with increasing interest Many secondary recovery processes are being developed that apply mineral processing technology. Gravity separation, magnetic separation and flotation have all emerged as explicit methods for recovering residual values from various process streams and hazardous constituents from waste streams. Recently, a technique for concentrating metallics has been successfully reintroduced. The concept of the alternating magnetic field eddy-current separator was developed over a century ago using rudimentary electromagnets (Patent 400317 issued to Thomas Edison on March 26, 1889). Widespread acceptance was, however, hindered by high costs, marginal results and poor economic incentives for secondary recovery. With the recent increased interest in secondary recovery and the development of high-energy rare earth permanent magnets, the eddy-current separator has now gained prominent acceptance. The separation forces imparted by an eddy current separator are the function of the magnetic field intensity and the alternating frequency of the magnetic field. The evolution of permanent magnets has provided a cost effective alternative for the generation of high-intensity magnetic fields. High-energy rare earth permanent magnets have substantially reduced the capital and operating costs over the electromagnetic circuits employed in antecedent eddy-current separators. Specifically, in recent years, the strength of permanent magnets has increased several fold with neodymium-boron-iron rare earth magnets now providing an energy product of 35 million gauss-oersted. Figure 1 shows the evolution in the strength of permanent magnets. The development of these rare earth magnets has led to the design of circuits possessing a magnetic force an order of magnitude greater than that of conventional permanent magnetic circuits. The eddy-current separator has been successfully applied in several metal sorting and recovery operations. Most common is the sorting of metal from shredded automobile scrap and municipal waste. With the advent of high-frequency, high-intensity magnetic fields, the separator has advanced to the point where it has direct application in the beneficiation of fine sized metals. Relatively fine sized (-1/4 in.) metal bearing slags and spent foundry casting sands as well as precious metal hearing electronic scrap demonstrate excellent metallurgical response to the eddy-current separator, and applications have progressed to finer materials and more selective separations. Theory Electrical currents are induced in all conductors when exposed to an alternating magnetic field. The induced current generates a magnetic field in the conductor that opposes that of the alternating magnetic field. Figure 2, is a schematic illustration of generated eddy currents. In this particular example, the alternating magnetic field is produced by a series of permanent magnets mounted on the circumference of a rotor. The permanent magnets have alternating polarity. As the rotor revolves, an alternating magnetic field is produced, and the rate of revolution determines the frequency of the alternating magnetic field. When a conductor, such as a metallic disc in the illustration, is placed in the alternating magnetic field, a closed loop current flow occurs. The current loop in the conductor produces a magnetic field that is a mirror image of the alternating magnetic field. At any point in time, the induced magnetic field in the conductor directly opposes the alternating magnetic field. This opposition of magnetic fields produces an instantaneous repulsion in the conductor. The conductor is consequently repelled from the rotor. The alternating magnetic field has no effect on nonmetallic materials as they pass through the magnetic field and discharge the rotor in a natural trajectory. [ ]

Jan 1, 1992