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By Marc Lonoff

Byproducts are more important to the copper mining companies than to the copper market. Copper ores frequently contain gold, silver, molbydenum and cobalt. With the increase in the prices of these metals copper mining has become more profitable. If byproduct prices remain high, additional firms will be attracted to the copper industry; the increased supply of copper will reduce the long-run copper price. However, this is unlikely to happen because the markets for the copper byproducts, especially molybdenum and cobalt, are small. Increased recovery from copper and other sources will depress the prices of these byproducts before the copper price is significantly affected. Should byproduct prices remain high the copper market will both settle at a lower long-run price and be more unstable in the short run. Since changes in the copper price do not affect the entire earnings of a multi-metal mine, the copper price must fall further before such mines reduce output in the short run. Higher byproduct revenues will make copper supply less responsive to copper price; shifts in copper demand will result in greater copper price fluctuations in the short run than they did before.

Jan 1, 1980

By Ross A. Scarano

It wasn't until late 1976 that the U. S. Nuclear Regulatory Commission (NRC) set about to address the uranium tailings issue in earnest. It was decided that a generic environmental impact statement related to uranium milling operations would be prepared to support formal tailings regulation. We recognized, however, that this was a task that would take many years to complete and we could not take a "business as usual" approach to tailings management in the interim; the issue was too sensitive. To facilitate licensing during the interim period, the NRC developed guidelines in May 1977, for the industry in the form of the following performance objectives for tailings management: Siting and Design 1. Locate the tailings isolation area remote from people such that population exposures would be reduced to the maximum extent reasonably achievable. 2. Locate the tailings isolation area such that disruption and dispersion by natural forces is eliminated or reduced to the maximum extent reasonably achievable. 3. Design the isolation area such that seepage of toxic materials into the groundwater system would be eliminated or reduced to the maximum extent reasonably achievable. During Operations 4. Eliminate the blowing of tailings to unrestricted areas during normal operating conditions. Post Reclamation 5. Reduce direct gamma radiation from the impoundment area to essentially background. 6. Reduce the radon emanation rate from the impoundment area to about twice the emanation rate in the surrounding environs. 7. Eliminate the need for an ongoing monitoring and maintenance program following successful reclamation plan. 8. Provide surety arrangements to assure that sufficient funds are available to complete the full reclamation plan.

Jan 1, 1980

By Alessandro Navarra, Aldo Quelopana

Sophisticated models have progressively been developed to address the challenges related to long-term, openpit mine planning under conditions of geological uncertainty. Prior research has acknowledged that strategies for mine planning and the design of mineral concentrators are interdependent; thus, it is highly desirable to optimize them together. However, achieving detailed holistic optimization of the mineral value chain remains unresolved because of the inherent limitations associated with mathematical formulations and computational processing capacity. This paper details a method that contributes to bridging these limitations by employing a novel parallelized variable neighborhood descent approach combined with an embedded mass–balance component using linear programming techniques refined through Dantzig– Wolfe decomposition. This approach is exemplified through a case study of a gold deposit, which illustrates the enhanced performance capabilities of the new algorithm. The findings demonstrate significant improvements in the optimization process for mine planning, providing a stronger link between the mine’s output and processing plant’s capabilities.

Mar 1, 2025

By S. D. Bearden

The world's reserve base is adequate for at least 100 years at the current consumption rate. China, India, and the U.S. are expected to remain the leading producing countries. The U.S. will continue to be the largest consumer of the production. None of the known substitutes for barium sulfate are expected to impact existing applications. World production in 1995 was 4,410Mt. This is about 50% of the projected capacity. Consumption is directly proportional to hydro-carbon well installation activity. Imports are expected to continue to supply more than half of the U.S. requirements.

Jan 1, 1997

By Dan Eyde

Low levels of thallium were detected in the mine water drainages, and process water discharges of western mining and smelting operations. This required remediation under state regulatory standards, which allow discharges of no more than .0017 ppm thallium in mine water discharges. Influent streams containing thallium can be mitigated to state discharge standards after a single pass through the series of fluidized upflow columns. Test work to determine the optimal flow rates used pilot scale systems at two separate locations treating 5 - 25 gpm of effluent. The test system at the gold mine mimics the full-scale system, which will be based on the existing upflow carbon tanks that have been converted to zeolite columns. The system installed at ASARCO's East Helena smelter has a far more complex influent stream with a high loading of competing cations. Nevertheless the columns filled with CABSORB® are successfully mitigating the thallium contamination. CABSORB® ZS500RW is a product based on the sodium analog of the zeolite mineral chabazite named herschelite.

Jan 1, 1998

By Wayne S. Cavender

The geochemical association of arsenic and gold in epithermal precious metal deposits of the Basin and Range province is well documented, and in this paper I wish to discuss the evaluation and utilization of this element association for geochemical gold exploration. In 1961-62, I conducted an exploration program on lands controlled by Getchell Mine, Inc, and centered about the Getchell gold mine itself, Besides exploring for new gold deposits, the program was to evaluate these lands for potential deposits of any type; thus, a multi-phase program encompassing a number of exploration methods was conducted. I shall not elaborate on the process of designing the program or of integrating the various methods, but for gold exploration, geochemical methods were determined to have the best potential. This paper is based on that effort. Figure 1 shows the exploration area, which covers the northern half of the Osgood Mountains in eastern Humboldt County, Nevada. The Getchell $line is on the east flank of the range and is about 40 miles northeast of Winnemucca.

Jan 1, 1964

By John W. Reddy

The C&NW Ore Dock at Escanaba, Michigan, is a major terminal on Lake Michigan for iron ore pellets arriving from the Marquette Iron Range located 112 km (70 miles) to the north. In an average year, the terminal handles in excess of 8 000 000 Mg (LT) of iron ore pellets consigned to a number of major steel companies. It is important to the steel companies for both cost control and operating efficiency that each cargo be sampled as accurately as possible in order to determine the physical and chemical properties of the pellets. This paper describes the equipment and operating procedures of the sampling facility and Presents some sampling data.

Jan 1, 1985

By D. J. Rose

The San Miguel Mine is owned by San Miguel Electrical Cooperative, Inc. and operated by Atascosa Mining Company, a wholly-owned subsidiary of Morrison-Knudsen Company, Inc. This multiseam, single-zone lignite surface mine is located near Jourdanton, Texas, 110 kilometers (68 miles) south of San Antonio. Lignite extracted from four closely-spaced seams is used to fuel the 400-MW San Miguel Power Plant. Recovery depths range from 7 to 37 meters (25 to 120 feet). The mine began stripping operations in the spring of 1980 and now produces approximately 2.5 million tonnes (2.8 million tons) of lignite annually. Atascosa Mining Company is responsible for production, maintenance, engineering, and management services. Production responsibilities include topsoil removal, overburden removal, lignite mining, spoil pile regrading and topsoil replacement, as well as ash disposal and construction and maintenance of water retention and diversion facilities.

Jan 1, 1984

By C. H. Grant

On the Mesabi Range, Ammonium Nitrate is used for blasting a variety of materials having widely varying blasting characteristics. The materials vary from hard, dense, magnetic taconite, which requires heavy blasting, through relatively soft, earthy, direct shipping ores, which require only light blasting to facilitate shovel operation. In view of the fact that materials gradational between these two end members are encountered in large tonnages, it is evident that a wide range of blasting situations face the mine operators on the Mesabi Range. In April of 1956, at Cleveland-Cliff s Hawkins Mine near Nashwauk, Minnesota, a fertilizer grade of Ammonium Nitrate prills was first used as a blasting agent. This first attempt was made without the addition of any carbonaceous material and even though it did go off, the force was not sufficient to produce the required results. Fuel oil was then added In the amount of one gallon for each 80 pounds of Ammonium Nitrate, with the oil and Ammonium Nitrate being added to the hole simultaneously. This blast was successful. Since then most of the mining companies have used Ammonium Nitrate, experimenting with various ratios of oil and fertilizer, mixing these ingredients either before or during loading of the holes. Since the additional of fuel oil to the Ammonium Bitrate before loading produces a more uniform saturation, most companies have adopted the method of pouring the fuel oil directly into the Ammonium Nitrate bags and then pouring the mixture into each hole. The ratio of 3- ½ quarts of fuel oil to each 80 pound bag of Ammonium Nitpate prills is now being used.

Jan 1, 1958

By N. W. Johnson

The behavior of non-sulphide gangue in chaloopyrite flotation circuits has been investigated. Plant and laboratory tests were carried out on five different ores, and linear relationships were found to exist between the rates of recovery of water and free nonsulphide gangue in the concentrates although there was evidence from pilot plant tests that these were linear approximations to parabolic curves over the limited regions which were observed. There was evidence that the free non-sulphide gangue enters the concentrate by hydraulic classification and a classification function has been proposed to define this behavior. This function is suitable for inclusion in a mathematical model of the process.

Jan 1, 1972

By M. Rieber

The potential for the wide-spread commercialization of superconductivity, the disappearance of all resistance to a direct current (D.C.) electric flow, began in 1986-87 with the development by Bednorz and Muller at IBM's Zurich Laboratory of an yttrium -barium -copper oxide conductor which attained zero resistance at 90t:. Although the status of superconductivity is still pre-bench scale, it is useful to forecast its probable effects on the copper industry. I t should not be forgotten that at their inception, the impacts of transistors, semi-conductors, thin films and fiber optics on the electric/electronics sector of this industry, were largely underestimated. Superconductors are not metals, but a class of ceramics. They represent an efficiency increase of one or more orders of magnitude. If their development is to be a boon to the copper industry, rather than a reduction of metal demand through miniaturization or material substitution, vastly expanded copper containing electrical uses must be in prospect. In this paper the projected uses of high temperature superconductivity are examined, followed by the remaining problems to be overcome. Assuming success, a time horizon for maturation is estimated. The penalties for the non-recognition of new markets and material substitution are shown on the basis of past forecasts. Finally, the application of successful superconductivity to the copper industry over the forecast period is estimated.

Jan 1, 1990

By L. S. Fountain

A national survey, 1978-1980, found 180,973 waste impoundments used by industrial mining, municipal and other interests. Possibly 27,000 contain hazardous materials. The potential hazard of leaks polluting water supplies is a growing concern. An electrical technique was developed to efficiently and speedily detect and locate leaks in geomembrane-lined liquid impoundments without emptying the contents. A potential applied between the liquid and earth causes electric current to flow through leaks in the insulating geomembrane material to ground. The cur- rent density around the leak is used to detect and locate the leak. Field tests show single and multiple leaks 2.54 cm in diameter or less can be detected and located to within less than 30 cm.

Jan 1, 1986

By Gerald W. Elger

Research at the Albany Metallurgy Research Center has shown that high-purity rutile can be produced from relatively low-grade ilmenite obtained from a massive rock deposit. Ilmenite is first smelted in an electric-arc furnace to separate the iron and produce a slag enriched in titanium dioxide. Titania slag mixed with a phosphate flux is then oxidized to synthesize rutile and form a phosphate-glass matrix which contains the impurities. Attrition scrubbing the treated slag in dilute solutions of phosphoric or sulfuric acid liberates the rutile, which is concentrated by physical methods. Tests show that synthesized rutile containing 95 to 97 pct titania responds to chlorination at the same rate as natural rutile.

Jan 1, 1973

By Harvey Parker

"The International Tunnelling and Underground Space Association (ITA) is a nonprofit organization that represents all aspects of the tunneling and underground space industry worldwide. Next year, the ITA will be holding its annual World Tunnel Congress (WTC) in San Francisco, CA, April 22-28, 2016. The ITA’s mission is to be the leading international organization advancing the entire industry and promoting the use of tunnels and underground space through knowledge-sharing and application of technology. This article updates a series of articles about the ITA prepared in 2007 by Harvey Parker, former president of the ITA, in anticipation of the next WTC in San Francisco.ITA accomplishes its goals through a range of activities that includes organizing conferences, workshops and meetings, working group and committee studies, training, experiments and other activities. ITA is also involved in the publication of proceedings, reports, and guideline documents as well as facilitating interaction among its membership and with sister organizations and decision makers. ITA currently includes 73 member nations and several hundred affiliate members, including 15 prime sponsors and 63 supporters. ITA’s membership is comprised of member nations as well as sponsors and affiliate members.The United States has had a prominent role in ITA since its 1974 inception, when it was formed as a result of a worldwide survey conducted in the early 1970s by the Organization for Economic Cooperation and Development (OECD). Bill Lucke, from the U.S., who was in charge of tunnels for the U.S. Federal Railroad Administration, was a member of the organizing committee that created ITA and became a vice president of ITA. Jack Lemley served as president of ITA from 1983 to 1986. Dick Robbins was active in ITA and served for many years as a member of the ITA’s Executive Council and as first vice president. Harvey Parker served as president of ITA from 2004 to 2007. Amanda"

Jan 1, 2015

By Brianna Eiter, Max Barham, Tim Bauerle

While not well established, there is evidence that the mining industry is encumbered by several work-related fatigue risk factors. Compared to other industries, mine workers are more likely to report inadequate sleep and work longer hours per day. Given these observations, there is a critical need to identify effective ways to intervene, manage, and mitigate mine worker fatigue and sleepiness when present. One barrier to this is confusion around the similarities and differences between fatigue and sleepiness, which can result in these terms being treated as interchangeable regardless of context and make it difficult to assess and mitigate safety risk.

May 1, 2024

By J. A. Herbst

It is widely recognized that Semiautogenous Grinding (SAG) circuits require the use of effective process control techniques to achieve their full processing potential and to protect them from the harmful effects of overloads and grind-outs. This requirement is even more essential as the variability of the ore being processed increases. The new Chino Mines Company concentrator located near Santa Rita, New Mexico started operation in June of 1982. At least eight major rock types are mined and milled. Ore hardness, feed size, and specific gravity are quite variable. Typical feed rates per grinding line are 850-900 tph but extremes of 260-1200 tph have been encountered. Normal feed rate variations of between 400 and 1100 tph are encountered on a weekly and sometimes daily basis. Feed size varies with rock type from a maximum of eight inches for the harder ores to two inches for the softer ores. One somewhat unique characteristic of the Santa Rita ore body among major copper mines is the wide variation in ore specific gravity. Specific gravities of the major rock types range between 2.7 and 3.6. The specific gravity variations are due to large changes in magnetite concentration throughout the pit. The result of this is large variations in SAG mill throughput which can have a harmful effect on downstream ball milling and flotation performance. Due to these wide fluctuations in ore characteristics, it was recognized soon after startup that successful operation of the grinding circuit and the plant at large was dependent upon the development of an effective automatic grinding control strategy. Research at the University of Utah has suggested that control based upon critical but difficult or costly to measure variables would improve automatic control performance. A project team made up of the Chino process control staff, Kennecott's Process Control department and the University of Utah Metallurgy Department was established to assess these concepts at Chino. This paper describes the development and on-line plant implementation of an Extended Kalman Filter that uses simple models of the SAG milling process, to predict the volumetric loading, the rock mass, the water mass, and the ball mass within the SAG mills at Chino. The on-line estimation of these parameters is the first step in the development of an integrated SAG mill/ball mill control strategy which is hoped to L eventually maintain the grinding circuit at its maximum capacity, while balancing the grinding load between the SAG and ball mills. Examples of long term estimation with the models and filter are shown for typical operating conditions as well as a SAG mill overload and grind-out.

Jan 1, 1983

"In this review, the sintering process is first described and analyzed to identify the key factors affecting the structure and quality of iron ore sinter. Under fixed sintering conditions, the granulation efficiency, nucleus stability and primary sinter melt volume and properties of the iron ore are considered to have significant influence on the sinter structure and quality. Discussion is then focused on the effects of the chemical, physical and mineralogical characteristics of the iron ore on these key factors, and the consequences for sinter quality.IntroductionSintering is the most economic and widely used agglomeration process to prepare iron ore fines for blastfurnace use. In modern blast furnaces, particularly in East Asia, iron ore sinter typically constitutes more than 70% of blast-furnace ferrous feed. High sinter quality and efficient sinter production are thus required both to withstand extreme operating conditions and maintain the productivity of modern blast furnaces. At the same time, due to the increasing depletion of high-grade iron ore resources from large deposits, iron ore producers are moving toward developing an increasing number of deposits of much smaller sizes to maintain current production levels. It is therefore imperative for iron ore producers to develop long-term strategies to maintain the quality and consistency of the iron ore fines they are producing while exploiting these smaller, complex deposits. The iron grade, gangue minerals present, overall mineralogy as well as physical characteristics of iron ore fines being mined from these different deposits vary considerably. Overall, ores now have highly complex mineralogy, are becoming more porous and friable, and contain increasing amounts of gangue minerals, which will have important implications for the sintering process and sinter quality.Blending is one of the most effective options being explored by iron ore producers to deal with multiple small complex deposits. This allows the iron ore producers to reduce the number of products and take full advantage of the unique characteristics of each individual deposit to achieve long-term product consistency while increasing production. Blending is also a common practice in sinter plants as it is almost impossible to produce from one single ore a high-performance sinter mixture with the required processing characteristics. A typical sinter mixture used in Japanese steel mills (Nakano and Okazaki, 2007; Matsumura et al., 2013) often contains five or more ores to achieve balanced sinter quality and productivity with relatively low cost of raw materials."

Jan 1, 2015

By Steven W. Hunt, Glen R. Frank

Assessment of abrasivity and cutter life are necessary to properly manage risks when tunneling in mixed face ground which includes ground with cobbles and boulders. Maximizing cutter life requires: (1) abrasivity and strength parameters for soil matrix and rock clasts, (2) methods of combining both, (3) proper selection of cutters and (4) modified TBM operation including use of boulder detection methods from the TBM to help make operation decisions. This paper presents approaches for addressing these factors sufficiently to improve tunneling success in mixed-face and cobbly-bouldery ground. Current laboratory abrasivity testing will be assessed along with equivalent quartz content correlations to soil matrix and rock clast abrasivity. New approaches to combining abrasivity testing of both the soil matrix and rock clasts for various cobble and boulder volume ratios will be suggested to estimate cutter life and intervention intervals. Methods for detecting boulders and using detection data to modify TBM operations to minimize boulder impacts are provided.

Jun 13, 2021

By L. Figueroa

Electrochemical methods have potential to treat waters impacted by mining, while simultaneously producing a recoverable metal product to off-set treatment costs. Mining-impacted waters may present challenges with electrochemical treatment due to low concentrations and complex solutions of numerous dissolved metals. This paper presents an evaluation of the potential strengths and limitations of abiotic electrowinning of mining-impacted waters. In particular the impacts of chemical composition on metals removal are evaluated. Results of bench-scale experiments demonstrate the potential to remove metals on the cathode (copper, cadmium, lead), as well as the anode (manganese). Pre-treatment for iron and aluminum may be needed and post-treatment pH adjustment would be necessary. INTRODUCTION Due to continually increasing demand for metals, new technologies and innovative applications of existing technologies are needed to recover metals from mining-impacted waters. Electrochemical methods have long been used for metallurgical processes with solutions containing high concentrations of the target metal. However, electrochemistry also has potential to treat waters with lower metal concentrations, while simultaneously producing a recoverable metal product to offset treatment costs. Electrochemical water treatment may have several benefits over traditional alkaline treatment for acid rock drainage (ARD). Sludge produced from alkaline treatment has high water content that is difficult to dewater, even for treatment plants producing a relatively high-density sludge. For example, the Argo Tunnel Water Treatment Facility (Argo Facility) in Idaho Springs, Colorado uses hydrated lime to produce a high-density sludge with a solids content of 20 to 25 percent and filter cake with solids content from 30 to 35 percent [1]. Furthermore, costs for managing the sludge are significant, approximately $90,000 per year for treating approximately 150 million gallons of water [1]. Although not the case for the Argo Facility, sludge produced from alkaline treatment of ARD has potential to be classified as hazardous. Disposal of sludge also opens up the potential for future liability depending on the sludge’s chemical stability and methods of disposal. In contrast to alkaline treatment, electrochemical treatment produces metals in elemental and other highly-dense forms on the cathode. If metals concentrations and flow rates are sufficiently high, the metals recovered may help offset overall treatment costs. In addition, sludge production would be reduced, if not eliminated altogether, thereby reducing both disposal costs and potential future liabilities as well.

Jan 1, 2019

By William F. Lawrence

Within ten to fifteen years, coal-fired power generating stations will be producing over 40 million tons of coal-ash annually in the United States. The largest part of this ash will be emitted from the boilers, entrained in the off-gas stream and trapped as flyash. However, about 15 percent (six million tons) will he removed from furnace bottoms as bottom ash or molten coal-ash slag. In current practice, the molten coal-ash slap is generally water quenched and then transported either as a slurry or in granular form to storage or disposal areas. Although a small amount of this slag is marketed as abrasive grit or as roofing granules, most of it is considered a waste material which must be disposed of at considerable cost to the power companies and therefore to the public. The accom¬panying economic loss in terms of unused raw materials and displaced land is not as obvious but is just as real. The Coal Research Bureau at West Virginia University under the sponsorship of the U. S. Bureau of Mines has been examining the possible utilization of both coal-ash slag and flyash in the mineral wool industry as a method of partially alleviating the growing national problem of solid waste disposal. The potential marketing situation for mineral wool manufactured from coal-ash is illustrated in Figure 1. This bar graph depicts the growth in value of mineral wool shipments1 from 1949 through 1966. In this 17-year period, the value in¬creased by over 350 percent, more than 20 percent per year, despite a decrease in unit cost of mineral wool. It therefore appears likely that coal-ash could find a steady market as a supplement to existing sources of raw materials for mineral wool production.

Jan 1, 1970