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By Alexander N. Winchell

"Location. The copper mines of Michigan are all in the northern part of that state on the Keweenaw Peninsula, which extends from the (Michigan) mainland for about seventy miles northeasterly toward the middle of Lake Superior. The mines occur in a belt or zone occupying the central portion of the peninsula from end to end.. The most productive mines for many years past have been those located not far from the city of Houghton in' the central part of the zone, in a section extending about ten miles southwest of Houghton and fifteen miles northeast. The most important mines in order of location, from the northeast to south¬west, are the following: Mohawk, Ahmeek, Allouez, North Kearsarge, Wolverine, South Kearsarge, Centennial, Calumet. and Hecla, Osceola, Franklin, Quincy, Hancock, Isle Royale, Superior, Baltic, Trimountain, and Champion. The first three named are in Keweenaw county and all of the others are in Houghton county. Still farther to the southwest are the Lake, Mass, Adventure, Michigan, Victoria, and White Pine mines. These are in Ontonagon county.History. The exploitation of these copper mines extends back into prehistoric times. There is little evidence that the American Indians carried on mining operations in this region in the period shortly before the advent of white men, but there is abundant evidence that the ancestors of the Indians, •or some earlier inhabitants of the region, carried on primitive mining operations. For example, Mr. S. O. Knapp, Agent of the Minne¬sota Mining Company, in the winter of 1847-48, made the first discovery of prehistoric mining. This event is described as follows by Foster and Whitney :"

Jan 1, 1920

By R. B. Elver

The St Lawrence Seaway, a deep-water canal system between Montreal and Lake Ontario, was opened for navigation on April 25, 1959. Prior to the opening of the new Seaway, small boats known as canalers and a few deep-sea carriers, primarily from Norway since World War II, were the only ships able to journey past Montreal into Lake Ontario through the old Canadian St. Lawrence canal system. Thus it was necessary for many tons of bulk and general cargo to be shipped all-rail to and from Atlantic ports or to be transhipped to and from canalers. With the opening of the new Seaway, large Great Lakes bulk carriers and a much larger percentage of the world's shipping fleet are now able to sail directly from the sea to the heart of industrial North America. In this paper, the historical events leading up to the construction of the Seaway and the physical nature of the Great Lakes transportation system are briefly reviewed. Following this, an attempt is made to evaluate the effects of the new Seaway on Canada's mineral industry. Because the Seaway has been in operation for only one season, this paper must be considered only an interim report. Because of the importance of the Seaway to iron ore, this commodity will be dealt with in detail, although the effect on other mineral commodities such as coal, petroleum, nonferrous ores, iron and steel will be mentioned. At this time the author wishes to thank the various company and government officials who provided both factual information and critical opinions.

Jan 1, 1960

By V. Miller

C. Hertzler The difference of means of milling characteristics by rock and ore type is tested in a statistical manner in the paper. The null hypothesis being tested is that the sample means of two different populations are equal. It is assumed that the null hypothesis is true when performing the test. Because of this, acceptance of this hypothesis leads to the conclusion that the sample means of the two different populations are equal (or there is no significant difference between the sample means), not that the samples come from the same population, as the author asserts. Rejection of the null hypothesis leads to the conclusion that the sample means of the two different populations are not equal. A P value for this test is reported in Table 2 and is incorrectly identified as the probability that the two samples came from different populations. Actually, what was recorded was 100(1 - p) where p is the usual p-value. The usual p-value measures, on a scale of zero to one, the extent to which the data agree with the null hypothesis. It is the probability of observing a value of the test statistic (Z score) that is at least as contradictory to the null hypothesis as the one computed from the sample data (McClave and Dietrich II, 1982). The author makes no mention of the fact that were these tests to be conducted together, the chances of determining that the null hypothesis is not true when it is really true are increased considerably (Snedecor and Cochran, 1980). This is a multiple comparisons problem and should be dealt with accordingly. The usual methods involve adjusting the level of the individual tests. Table 2 reports an incorrect 100(1 - p) value in the comparison of concentrate grades for other rock types with .30 to .69 % Cu vs other rock types with .70 + % Cu; 86 % should be 98.6 %. Although the article can be criticized for poor data presentation and discussion of that data, the point the author makes regarding the use of these statistics in the ore reserve estimation process is well taken. It does not appear that inaccuracies in the statistical interpretations have hindered that usefulness. References McClave, J.T., and Dietrich, II, F.H., 1982, "Statistics," Dellen Publishing Co., San Francisco and Santa Clara, CA, 766 p. Snedecor, G.W., and Cochran, W.G., 1980, "Statistical Methods," The Iowa State University Press, Ames, IA, 561 p. Reply by V. Miller After reading Ms. Hertzler's comments, it appears that the differences noted were basically semantics. If the paper is ever presented at a math symposium, some changes will be needed. When deciding the best way to present the data to mining engineers and geologists, I decided that presenting the probability that the two sample groupings came from different populations (reverse to the Null hypothesis) was easier and would require less verbage to explain. Hence, the 100(1 - p) difference which was noted. Ideally, I would have preferred to give the recovery and concentrate grades, then comment which ones had significant differences. Unfortunately, Kennecott Corp. did not grant permission to publish the ore body's actual recoveries and concentrate grades. The conclusion is that there was, as expected, a relationship between the ore's geologic properties and the metallurgical properties, and by determining this relationship, the overall mineral model was greatly improved.

Jan 8, 1984

By Roger D. Sharpe

Oklahoma contains extensive resources of high-purity gypsum that were deposited in the Anadarko and Hollis basins during Permian time. The gypsum resources and reserves are estimated to be about 48 billion short tons and a; located in the western portion of the state. Oklahoma is the largest producer of gypsum products in the United States. The Blaine Formation and the Cloud Chief Gypsum contain several beds of minable thickness. Four stratigraphic units in the Blaine Formation are quarried in Oklahoma. The Shimer, Nescatunga, and Medicine Lodge Members are quarried in northwest Oklahoma. The Van Vacter Member, consisting of three gypsum beds, is quarried in southwest Oklahoma. The Cloud Chief Gypsum is quarried in the west-central part of the state. The gently dipping gypsum in the Blaine Formation generally crops out along low escarpments and is covered in the downdip direction by increasing overburden, consisting of sand, shale, and/or dolomite. Anhydrite occurs in the downdip direction under the thicker overburden. The Cloud Chief Gypsum crops out as hills, which are eroded remnants of a more widespread, massive sulfate unit. All of the gypsum produced in Oklahoma is extracted using quarrying methods. A variety of products are made from gypsum quarried in Oklahoma. The products are manufactured from uncalcined, calcined, and deadburned gypsum. Products vary from raw, ground gypsum used for agriculture, to high-value-added industrial plasters, cements, and fillers produced from calcined gypsum. A sampling of the many products manufactured from Oklahoma gypsumincludes: (1) agricultural-soil amendment; carrier for insecticides, pesticides, and herbicides; calcium supplement in animal feeds; (2) gypsum wallboard-common, fire-resistant, and water-resistant varieties; (3) industrialgypsum plasters-art and casting, pottery and ceramic, molding and tooling, crayons, wall patching; (4) industrial gypsum cements-oil-well cement, high-strength statuary, high-strength tooling, fiber-reinforced architectural, road and bridge repair; (5) food and pharmaceutical-filler and binder in aspirin and other medicines, yeast activator in brewing of beer, moisture absorbent in bread and pizza dough; and (6)portland-cement retarder-ground with clinker to control setting time.

Jan 1, 1999

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%. Metals 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, 2002

By A. D. Ajak

A complete mining cycle involves digging, loading, hauling and dumping of the materials. Moving the ore from the pit to the crusher or to the waste dump requires access routes, which are termed haul roads. These roads have to be designed, constructed and maintained. A review of the literature indicates a common consensus among researchers that there should be a balance between haul road economics and safety of the road users. However, there is no universally accepted theory on the design of haul road geometry and, in particular, road dimensions. The current industry practice is based on empirical data and rules of thumb developed by engineers. Therefore, this paper will use the overlooked and less valued branch of mathematics, arithmetic progression, to derive a road width equation. It is beyond the scope of this paper to discuss all road design components. The focus will be on the geometric aspects, which more often have a direct impact on road safety. In this paper, the current design practices and techniques for haul road geometrics design will be explored, using arithmetic progression to formulate road width equations, case examples to apply the equation and then validating the results with conventional techniques that have confirmed the reliability of road width equations, thus eliminating use of tables during design.

Jan 1, 2012

By L. Yuan, A. Smith

"NIOSH’s mine fire simulation program, MFIRE, is widely accepted as a standard for assessing and predicting the impact of a fire on the mine ventilation system and the spread of fire contaminants in coal and metal/nonmetal mines, which has been used by U.S. and international companies to simulate fires for planning and response purposes. MFIRE is a dynamic, transient-state, mine ventilation network simulation program that performs normal planning calculations. It can also be used to analyze ventilation networks under thermal and mechanical influence such as changes in ventilation parameters, external influences such as changes in temperature, and internal influences such as a fire. The program output can be used to analyze the effects of these influences on the ventilation system. Since its original development by Michigan Technological University for the Bureau of Mines in the 1970s, several updates have been released over the years. In 2012, NIOSH completed a major redesign and restructuring of the program with the release of MFIRE 3.0. MFIRE’s outdated FORTRAN programming language was replaced with an object-oriented C++ language and packaged into a dynamic link library (DLL). However, the MFIRE 3.0 release made no attempt to change or improve the fire modeling algorithms inherited from its previous version, MFIRE 2.20. This paper reports on improvements that have been made to the fire modeling capabilities of MFIRE 3.0 since its release. These improvements include the addition of fire source models of the t-squared fire and heat release rate curve data file, the addition of a moving fire source for conveyor belt fire simulations, improvement of the fire location algorithm, and the identification and prediction of smoke rollback phenomena. All the improvements discussed in this paper will be termed as MFIRE 3.1 and released by NIOSH in the near future INTRODUCTION The MFIRE program, originally developed in the 1970s by the U.S. Bureau of Mines (now the Office of Mine Safety and Health Research (OMSHR) at the National Institute for Occupational Safety and Health (NIOSH)) and Michigan Technological University, has been a mainstay in modeling of the mutual influences between a fire and the mine ventilation system during an underground mine fire. Several update versions have been released over the years, including MFIRE 1.27, 1.29, 1.30, 2.0/2.01, 2.10, and 2.20. The MFIRE program logically comprises four parts: (1) a conventional network calculation, where it performs the basic network balancing without considering heat or mass transfer; (2) a temperature calculation to establish the reference temperature distribution before a non-steady state (transient-state) simulation; (3) a transient-state simulation that follows changes in ventilation step-by-step to produce a continuous description of the temperature distribution, smoke, and contaminant spread through the ventilation system during a fire event; and (4) a quasi-equilibrium simulation to predict the state of the ventilation system after a relatively long period of time (defaulted as 5 hours in MFIRE) as the fire reaches a quasi-steady state. In summary, MFIRE is a computer simulation program that performs normal ventilation network planning calculations and dynamic transient-state simulation of ventilation networks under a variety of conditions including the influence of natural ventilation, fans, fires, or any combination of these (Chang et al., 1990)."

Jan 1, 2016

By A. D. Trippel

The Cripple Creek Mining district is located in Teller County, Colorado, 30 km west of Colorado Springs and 9 km southwest of Pikes Peak (Fig. 1). Since its discovery in 1891, the district has produced almost 21 million tr oz of gold (Gott et al., 1967), most of which has been from high-grade vein deposits. Globe Hill is located in the northern part of the district (Fig. 2). Production from its summit has yielded over 100,000 tr oz of gold. Early production was concentrated along high-grade veins and fault structures, but emphasis was soon placed on the extensive, low-grade (0.0X oz/t), breccia-hosted mineralization. From 1977 to 1981 Newport Minerals, Inc., a subsidiary of Gold Resources, Inc., mined 680,000 t of low-grade gold ore from the Globe Hill pit (Fig. 3) and production is expected to resume in 1986. These strongly-altered and -oxidized breccias are amenable to bulk-mining methods, and thus similar deposits are currently being sought elsewhere in the district. Numerous publications and reports discuss the breccia-hosted mineralization at Globe Hill. They include Cross and Penrose (1895); Argall (1905, 1908); Lindgren and Ransome (1906); Keener (1962); Peters (1982); Thompson, Trippel, and Dwelley (1985); and Trippel (1985). This preprint is a summary of the recently-completed research documented by Trippel (1985).

Jan 1, 1986

By M. Mikhaylenko

Rhenium, molybdenum and tungsten are the elements demanded by high-end technologies. These metals are found in process solutions in forms of their oxyanions: ReO4-, MoO42- and WO42-. The later two can exist in forms of iso- and/or heteropolyanions. Basically all three metals demonstrate very similar chemical behavior in aqueous solutions. Unfortunately, in their mineral sources these elements commonly accompany each other, like pairs of rhenium-molybdenum or molybdenum-tungsten. Their economical separation is a challenging task.

Jan 1, 2012

By H. Lowers, B. Van Gosen

The Iron Hill (Powderhorn) carbonatite complex is a 31 km2 alkalic intrusion located about 35 km south-southwest of Gunnison, Colorado. The intrusion has been well studied and described because of its classic petrology and architecture of a carbonatite-alkalic complex. The complex is also noteworthy because it contains enrichments of titanium, rare earth elements, thorium, niobium (columbium), vanadium, and deposits of vermiculite and nepheline syenite. In particular, the complex is thought to host the largest titanium and niobium resources in the United States, although neither has been developed. It may be economic to extract multiple resources from this complex with a well coordinated mine and mill plan.

Jan 1, 2007

By Ronald L. Wiegel

In a mineral processing plant there are a number of routine decisions which are based at least in part on the plant's metallurgical performance. Among these are those related to: 1) equipment functioning properly 2) suitable operating conditions 3) reagents achieving desired results 4} determining operating response to changes in ore 5) defining circuits offering potential for improvement A step beyond the routine, are the periodic management evaluations of operating supervision and technical assistance, which are based largely on profit -a direct function of are availability, metallurgical performance and operating costs. The "yardstick", excuse me -"meterstick", by which performance is best measured is the plant metallurgical balance, which tells not only what was produced but how it was produced. Since this metallurgical balance is directly related to both plant profits and individual rewards, it is only reasonable to make that "meterstick" as precise as humanly possible.

Jan 1, 1978

By S. Pastor, S. Hahn

"As the concept of autonomous haulage systems (AHS) moves from prototypes to production-ready applications, the operating performance of the haul road will become critical to the overall success of autonomy in mining. Deterioration in road performance will require remediation, human intervention and significant, albeit temporary, changes to operating procedures, to accommodate road maintenance. With autonomous trucks comes the opportunity to reduce road formation and operating width. This will, therefore, generate potentially significant reductions in stripping ratios and improvements to mine economics, but only if the design of the road, and its associated deterioration rate, is predictable and manageable, based on the materials used to construct the road and the maintenance interventions to be carried out on the road.This article presents the assessment of a digital photogrammetric approach to the characterization of a mine haul road surfacing, or wearing course material. Design and maintenance parameters for these roads are currently determined partly from physical particle size distribution (PSD) assessments of ‘in-road’ material. However, this approach does not accommodate the need, nor leverage the benefits from, AHS. The digital imaging approach is assessed in this article, using two standard digital analysis software tools, together with in-service mine haul road wearing course samples and images that are analyzed to determine the applicability and reliability of the approach to deliver a real-time assessment of haul road surfacing conditions and thus to identify the road maintenance interventions required to address deterioration.Enhancements in mine road design, construction and management for the past 20 or more years has largely been focused on short-term tactical needs. These improvements have not been matched by advances in the fundamental technologies that underpin mine road design and management and, although the quality of mine roads have probably"

Jan 1, 2015

By Xiaoyan Luo, Congcong Dai, Gaipin Cai, Xin Liu, Lu Zong

To overcome the difficulty of accurately judging the load state of a wet ball mill during the grinding process, a method of mill load identification based on the singular value entropy of the modified ensemble empirical mode decomposition (MEEMD) and a probabilistic neural network (PNN) classifier is proposed. First, the MEEMD algorithm is used to decompose the vibration signals recorded under different load states to obtain the intrinsic mode components, and a correlation coefficient threshold is used to select the sensitive mode components that characterize the state of the original signal. Second, singular value decomposition is used to obtain the singular value entropy. Finally, the load state of the wet ball mill is judged based on the magnitude of the singular value entropy. A characteristic mill load vector is constructed from the singular value entropies of the cylinder vibration signals recorded under different load conditions and is used as the input to a PNN, which then outputs the predicted ball mill load state; in this way, a load state identification model is established. Grinding experiments are presented to verify the effectiveness of the proposed method, showing that the method can accurately identify the load state of a wet ball mill. ()

By D. R. Tweeton

A modified push-pull field test and a computer model of cation exchange were developed to aid in evaluating cation exchange parameters prior to in situ mining. Reliable determination of these parameters is essential when modeling restoration of groundwater quality. The field test involves a much larger volume and much less disturbance to the ore sample than is feasible with laboratory measurements. This test can be performed in two or three weeks. It is relatively inexpensive, requiring one injection- production well and two or more wells for collecting samples of leach solution. The use of the model in interpreting test results is illustrated with field data from an in situ uranium mine. Much of the research was performed by the University of Texas at Austin, and was partially funded by the Bureau of Mines.

Jan 1, 1986

By Montaser S. El‑Salmawy, AHMED A. S. SEIFELNASSR, Ahmed Al‑Abady, Abdeaziem M. Abdelaal, Amr F. M. Ibrahim

Iron is a key detrimental impurity in silica sands that determines their contribution to high-technology industries. Herein, a simple ecologically sound approach is investigated for iron removal from a silica sand sample obtained from the El-Zaafarana area-Egypt. The sample was subjected to a detailed microscopic mineralogical study supported by XRD and XRF characterization. The sample was beneficiated using distilled water attrition scrubbing and screening over a 25 μm sieve followed by leaching using a mixture of equal amounts of phosphoric and oxalic acids. Leaching experiments were designed and analyzed using the Box-Behnken design (BBD) methodology. A model was developed and evaluated using the analysis of variance technique to map the relationship between the residual iron oxide in the produced concentrate and selected variables such as leaching temperature, oxalic acid, and phosphoric acid concentrations. XRD and mineralogical analysis reveal that quartz is the most dominant constituent of the studied sand and other minerals such as kaolinite, iron oxide, rutile, and zircon exist in trace amounts. The head sample shows a silica and iron oxide content of 95.69% and 2379 ppm, respectively. Attrition and separation over a 25 μm sieve increase the silica content to 97.05% and decreases the residual iron oxide to 455 ppm. The final product after leaching under optimized conditions shows 99.82% silica and 55 ppm iron oxide.

Aug 30, 2022

By T. A. Farr, I. A. Gibbs, F. Guevara, S. R. Simms, G. Nojima

This paper describes an installation of a medium-voltage adjustable frequency motor drive (AFD) on a high starting torque regrinding mill. This type of application is typically found in the mineral industry dealing with hard ore. The AFD electrical architecture is introduced from line to load. The type of closed loop encoder feedback motor control algorithm is briefly described. The results of the AFD motor identification auto-tuning are compared against the manufacturer’s supplied data. The motor drive performance results are shown for pre-ramp DC fluxing, high starting torque with overload current, excessive load torque stall condition, and blocked rotor. The instrumentation and arrangement for the two watt-meter method to capture low frequency data are presented. The data shown is from the input power quality meter, the AFD computer tool, the output motor protection relay, an oscilloscope, and load shaft connected strain gauge (rotating telemetry for torque assessment). These types of high starting torque constant torque loads are found in mining and process industry applications employing AC adjustable frequency drives. Using field results should help demystify the use of voltage matching output transformers in AFD applications including constant torque loads

Mar 2, 2022

By Yuting Xue, Mark Van Dyke, Joe Wickline

The understanding of coal mine roof lithology is a critical component in the determination of engineering solutions for roof control. Coreholes were the first technology available to determine lithology of the roof in reserve areas, but coreholes are typically drilled 500–2,500 ft apart due to their cost and sometimes reach more than $125,000 dollars per hole, depending on mine conditions. The next method developed to bridge this gap was the fiber-optic scope which is utilized in the roof at the faces of underground development. High-end fiber-optic scopes can also be costly (20,000–40,000 dollars) but are more affordable than drilling a corehole, and the information can be processed immediately to make quick roof support determinations. The fiberscope can be operated wherever a roof bolter can drill a hole, and there are no restrictions related to property owners, proximity to streams, elevation changes, etc. The latest borescoping method utilized by mining companies is the use of videoscopes. Videoscopes and all borescopes in general are limited by the lengths of the scope and the length of the borehole drilled in the mine. Videoscopes have the advantage of being able to record video while examining the roof lithology. The information can be recorded quickly underground and then be examined on the surface which allows anyone to capture the video so that a geologist can make lithology descriptions without ever going underground. In the past, videoscopes had limited resolution, a short battery life, were fragile and were relatively costly. As technology progresses, videoscopes have become more affordable, have increased battery life, and offer enhanced 1080p resolution. With the broader availability of affordable videoscopes, videoscopes can be more readily used in various mine environments at every active section underground. This paper will discuss the types of videoscopes available, the features that will aid in lithology description/identification, the deployment methods pertaining to supplemental roof support recommendations, and an advanced methodology to enhance accuracy in understanding roof lithology.

Feb 1, 2025

By J. F. Burr, D. Snyder, W. Calder

This paper provides a determination of the equivalent level of protection of the international standards relative to similar criteria used by the U.S. Mine Safety and Health Administration (MSHA) to approve two-fault intrinsically safe (IS) stand-alone equipment. U.S. mining law requires such a determination for MSHA to use alternatives to existing standards. The primary issue is to demonstrate that the international standards for equipment evaluation will provide at least the same level of protection for miners as the document currently used by MSHA.

Jan 1, 2018

By J. F. Burr, D. Snyder, W. Calder

This paper provides a determination of the equivalent level of protection of the international standards relative to similar criteria used by the U.S. Mine Safety and Health Administration (MSHA) to approve two-fault intrinsically safe (IS) stand-alone equipment. U.S. mining law requires such a determination for MSHA to use alternatives to existing standards. The primary issue is to demonstrate that the international standards for equipment evaluation will provide at least the same level of protection for miners as the document currently used by MSHA.

Jan 1, 2017

By Claude Deveau, Stephen R. Young

Introduction Tanco History Tanco is sometimes known as the Bernic Lake Mine. It is located about 180 km east-northeast of Winnipeg close to the Manitoba-Ontario boundary. Tanco operates an underground mine employing ramp access, room and pillar mining and shaft hoisting for the production of tantalum, lithium and cesium minerals. Tantalum recovery employs conventional gravity and centrifugal concentration methods along with a flotation process which recovers ultra-fine tantalum. All tantalum concentrates are shipped to Cabot Supermetals, Boyertown, Pa., for the production of tantalum chemicals and metals. Tanco also produces lithium products from spodumene ore. The lithium concentrates from Tanco are shipped worldwide for use in ceramics, specialty glass and mold powders. Cesium processing involves the dry grinding of pollucite as feed stock to the on-site chemical plant dedicated to the production of cesium formate, a high density drilling fluid. Tantalum milling operations commenced in 1969. In the early years of the operation, feed grades were three to four times as high as they are today. Coarse-grained tantalum mineralization with complete tantalum liberation at sizes of 300 µm allowed for easy recovery with conventional equipment such as spirals and shaking tables. Over the years, the process and feed material to the plant have drastically changed. Due to drastically reduced liberation sizes, efforts have been made to try to recover as much of the liberated particles as possible in order to maintain acceptable recoveries.

Jan 1, 2005