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By G. V. Campbell, O. T. Holdsworth, M. G. Nelson

A senior design project is required by all accredited mining engineering degree programs. Often referred to as the capstone of a student’s education, this project is expected to include all the important components of the preliminary economic assessment of a mineral prospect, including orebody modeling, grade and reserve estimation, selection of mining and processing methods, preliminary mine design, access and utilities, environmental compliance and reclamation, and financial analysis. Two of the authors (Campbell and Holdsworth) completed a senior project in 2021. They analyzed the Akie zinc deposit located in Canada. This paper summarizes the economic analysis portion of that project. The two primary objectives of this economic analysis were risk reduction and integration of economics and engineering. Addressing risk is important as risk is one of the primary concerns in mining investments. Risk reduction was the primary concern through the entirety of this economic analysis. Integration of financial analysis and engineering design was the first component of a risk reduction design. This allowed for financial and engineering design to be optimized in conjunction with one another. This produced benefits from both a financial and an engineering prospective. From a market, economic, and financial risk perspective, risk was reduced by forecasting multiple metal price scenarios, and then addressing the Akie project’s economic viability at each price point. Lastly, risk was address through consideration of nontraditional financing options. The project also sought to minimize financial and human capital risk, by proposing mutually beneficial cooperative social relationships and favorable work, schedules. Description of that work is not included in this paper.

Mar 2, 2022

By M. Frenzel, D. Ebert, K. Bachmann, A. D. Renno, R. Möckel, J. Gutzmer, J. Krause

With the increasing demand for metalliferous and mineral raw materials and the consequent depletion of the global natural resource base, the possible utilization of secondary raw material sources is receiving more and more attention. In the present study, we present results from a detailed vanadium deportment study of three basic oxygen furnace slag (BOS) samples known to containing elevated bulk concentrations of vanadium. Complementary analytical methods that were used to quantify the abundance and composition of V-containing phases include SEM-based automated mineralogy, X-ray fluorescence analysis, and X-ray powder diffraction as well as electron probe microanalysis. The vanadium deportment was quantified using Monte-Carlo simulations of the data obtained from automated mineralogy and electron microprobe analysis. The total V concentrations identified by XRF are between 1.7 and 2.2 wt.% V. The most important hosts of vanadium are larnite-, brownmillerite- and portlandite-solid solutions. In two samples Ca carbonates also significantly contribute to the V deportment, while wuestite, lime, and native iron do not contribute significantly to the vanadium deportment. A thorough consistency check identifies considerable uncertainties in the density of the V-bearing phases as the most likely reason to explain remaining discrepancies between measured and calculated V values.

Oct 14, 2023

By X. F. Liu, O. Buzzi, Y. Sieffert

This study falls in the context of underground coal fires (UCF) where burning coal can elevate the temperature of a rock mass in excess of thousand degrees. The objective of the research was to experimentally investigate the change in mechanical behavior of a rock when subjected to temperatures up to 900 °C. Several blocks of an Australian mudstone were collected from a mining site in New South Wales, Australia. X-ray diffraction and thermal-gravimetric analysis were conducted on powdered rock in order to determine the critical temperatures at which the main mineralogical changes occur. Then, cylindrical specimens were prepared from intact rock blocks for unconfined compression tests. These rock specimens were then treated by heating in a temperature-controlled furnace at temperatures varying from 100 °C to 900 °C. The heating process consisted of two stages: raising temperature with very slow rate of 1 °C per hour followed by a holding period of 24 hours and then a slow cooling process to room temperature. The compression tests were carried out on treated rock specimens to characterize the change in compressive strength. The macroscopical study was complemented by microstructural investigations via optical microscope, scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP). Results show that the unconfined compressive strength of mudstone decreases with increasing heating temperature up to 450 °C, beyond which it increases. This can be explained by the combined effects of micro cracks and mineral thermal reactions caused by heating process.

Jan 1, 2015

By V. A. Cooney

Introduction For the compliment paid me by the Institute's kind invitation to speak this afternoon, I am very grateful. For the astuteness of your officers in determining that encouragement should be given, through the medium of a paper, towards accident prevention in coal mines, the coal industry cannot but be grateful. Some day, and let us hope soon, a more developed paper may supersede this one. In the meantime, if some knowledge of what one coal field has been able to accomplish, even in the initial stages of its effort, will induce other fields and other sections of the mining industry to launch similar experiments, much good will result and a more developed dissertation on the subject will make its appearance.

Jan 1, 1946

By Shklyar FR, Bokovikov BA, Gordon YM, Scherbatskii VB, Yaroshenko YG, Shvydkii VS

The paper presents, for the first time, a complete mathematical model of the flow of gases in packed beds which describes the processes of gas-mechanics in iron blast furnaces and other shaft type smelting units. Good correlation between calculated and experimental results was obtained confirming the adequacy of the model. It is shown that the uniformity of gas distribution is related to the tuyere size and the extent of its protrusion into the furnace and that these variables may be used to regulate gas distribution across the furnace diameter. It is also concluded that furnace height has no significant influence on gas distribution. The necessity for a mathematical description of raceway phenomena has been experimentally proved. Conclusions from theory are shown to have profound implication to furnace design and operation.

Jan 1, 1975

By Loren R. Anderson

This volume documents the use of the probabilistic slope stability program PROBISH. The probabilistic slope stability program is an interactive program and is essentially self-tutorial. It prompts the user for the required input data as it is needed, and allows the user to correct mistyped data before analysis is initiated. The program computes safety factor probable Width of failing and probability of failure for a given circular failure surface. Four example problems are included to illustrate its use.

Jan 1, 1982

By A. J. Barry

A practical method has been developed and field tested which provides an estimate of the bearing capacity of mine roof and floor. The relationship between penetration of the strata and imposed loads is determined by in situ tests. Information of this type is needed to determine the maximum allowable pressure that may be applied by self-advancing supports on roof and floor of a longwall face without causing a punching type of failure.

Jan 1, 1970

By R. J. Kuczynski

The U.S. Bureau of Mines operated a 2,000-g (4.4-lb) batch process development unit for recovering platinum-group metals (PGM) from automobile catalysts. Virgin monolith, used pellet, and used monolith catalyst samples were tested. Leaching twice with 1-pct sodium cyanide (NaCN) solution at 1600 C for 1 h dissolved more than 95 pct of the PGM from virgin catalysts and more than 90 pct from used pellet catalysts. More than 85 pct of the PGM was dissolved from used monolith catalysts when a third autoclave step was added. Solid PGM concentrates containing more than 99.8 pct of the dissolved PGM and analyzing greater than 70 pct PGM were recovered by heating the pregnant leach solutions from virgin catalysts to 2500 C and used catalyst to 2750 C for 1 h. The solution after heating contained less than 0.2 ppm. total cyanide. The virgin residues passed the EPA Extraction Procedure Toxicity Test (EP Tox Test), the EPA Toxicity Characteristic Leaching Procedure (TCLP), and the California Waste Extraction Test (WET) for all elements except Ba. Adding sodium sulfate (Na2S04) to the virgin leach residues reduced the amount of Ba dissolved to an acceptable level. The used leach residues passed the EP Tox Test for all elements but failed the WET and TCLP for Pb.

Jan 1, 2010

By D J. Williams, G W. Wilson, S, A B. Tran

A comprehensive field program was implemented to evaluate the internal structure and hydrology of two full-scale waste rock piles. The excavation of waste rock dumps for in-pit disposal at the two mine sites provided an opportunity to characterise the in situ properties of the dumps given contrasting geologic and climatic settings. The internal structure and materials within the dumps were observed and sampled as the waste rock piles were being excavated and placed in the open pits for permanent closure. The field program was designed to fully characterise the structure and material properties of the waste rock. The alteration of the material by physical and chemical weathering was also observed. Samples were analysed for paste pH, water content, grain size distribution and geochemistry. In situ density and matric suction were also measured. Soil water characteristic curves and saturated hydraulic conductivity were measured for representative materials. These properties were used to predict seepage pathways through the waste rock and the resulting outflow geochemistry using the finite element model SEEP/W. The materials in the dump at Site 1 were predominantly fine-grained in texture and highly weathered. The presence of dipping beds with alternating coarse and fine materials was evident throughout the profile of the dump. The structure of the waste rock appears to have an impact on the hydrologic pathways within the waste rock pile. The material in the dump at Site 2 was found to be competent and resistant to particle size breakdown. The particles range in size from clay size to large boulders with the median particle size being approximately 125 mm in diameter. The coarse-grained texture of the waste rock resulted in a loosely packed arrangement of coarse particles with little matrix material infilling the pore spaces between the coarse-grained particles. Seepage modelling for Site 1 was completed to predict seepage paths based on observed structure and hydraulic properties measured in the laboratory. The modelling showed that materials with a fine grain size distribution become the dominant pathways for flow through the waste rock pile. The modelling also showed that layers with high silt and sand contents are subject to the highest flow rates. Finer grained clay rich layers have a low hydraulic conductivity and do not convey large volumes of water. Alternately, coarse gravel and cobble materials are unsaturated under values of matric suction that approach the residual water content of the material and do not transmit liquid water. The seepage modelling together with the results of the geochemical analysis show that the dominant particle size that receives the most fluid flow and flushing ranges from fine sand to silt, corresponding to materials with air entry values ranging between 5 kPa to 50 kPa.

Jan 1, 2003

By Richard N. Appling

This compilation presents information obtained through investigation of manganese deposits and a reconnaissance of potential manganese-bearing areas of southwestern Oregon and Del Norte County, Calif., from October 1952 to September 1955. The report includes maps, assays, and preliminary examination data on 39 manganese deposits distributed throughout Curry, Coos, Douglas, Josephine, and Jackson Counties, Oreg., and 1 deposit in Del Norte County, Calif. On the basis of mineral content the deposits can be divided into three groups: 1 Manganese silicate deposits, manganese oxide deposits, and manganiferous iron de-posits. Generally the oxides occur along the coast in the Curry-Coos County area, the manganiferous iron deposits are in the Josephine-Douglas area, and the manganese silicates are found in both the Josephine-Douglas and Jackson County areas. The deposits are characteristically irregular in form and usually small. Most silicate and manganiferous iron deposits are in metasediments of Triassic (?) age; oxide deposits are in sediments varying in age from Jurassic to Eocene.

Jan 1, 1957

By Herty, C. H.

Present-day interest in the question of "dirty steel" has arisen primarily from the increasingly rigid specifications on various grades of steel and from the growing conviction that non-metallic inclusions are the source of many of the difficulties in meeting these specifications. The importance of inclusions has unquestionably been over-emphasized in many cases, but on the other hand many unpublished instances could be recorded where all evidence pointed to inclusions as the primary cause for the failure of steel in rolling or in service. The solution of the problem of dirty steel is not a matter of a few years. There are almost numberless types of inclusions. They segregate in steel ingots in an entirely different manner from other impurities, and, at best, only a start has been made in developing correct analytical methods for their determination. Most of the writers in the field have expressed opinions rather than given facts, and so many variables enter into the manufacture of steel that a study of plant conditions is difficult unless definite facts on certain phases of the inclusion problem are available. This statement is not intended to convey the idea that little work has been done on this problem. On the other hand, the number of investigations has been large, but in most cases too many variables have been present to allow definite conclusions to be drawn. In the body of the text, reference to previous investigations is made at suitable points. Rather than burden the reader with a lengthy review of the literature on the general subject of inclusions, reference to the particular works pertinent to the subject matter of the bulletin has been discussed. Three excellent bibliographies b on the subject have been lately published: one by the Committee on

Jan 1, 1957

By John Bley

White Pine Copper Company operates a mine in the Upper Peninsula of Michigan using a modified room-and-pillar system for extracting ore.1 Mine production averages 15, 500 tons per day. The terrain is predominantly level and the depth of cover varies from 500 to 800 feet over the present workings with depth increasing as mining progresses down the dip. The deposit is situated on a low angle plunging, anticlinal structure composed of sedimentary beds. Local terminology for the stratigraphic units which contain the ore horizons, named in ascending order, is as follows: lower sandstone, parting shale, upper sandstone and upper shale. The ore zones of copper enrichment are, contained in the parting and upper shales. The parting shale will vary; from 6. 5 to 9.0 feet thick; the upper sandstone from 2 to 10 feet; and the upper shale from 1. 5 to 6. 5 feet. Two variation of the room-and-pillar system are used to extract the ore depending on grade and local ground conditions. One system is called the parting shale method and recovers the parting shale only. This system requires a mining height of 8 1/2 feet to accommodate large-scale, high-capacity equipment and this working height is obtained by removing approximately 1 to 2 feet of the barren lower sandstone with the ore. Under the second system, locally termed full column, the mining height is about 14-1/2 feet and this system removes the parting shale, the upper sandstone and the lower mineralized zone, approximately 1-1/2 feet, of the upper shale at which point it is possible to maintain a competent back (Fig. 1).1

Jan 1, 1964

By Rory P. A. Ball, Mark Briggs, Martin Dix

"Tunnel professionals should inform project stakeholders on the reality that tunnel projects are not 100 percent devoid of the need for excavations or public inconveniences during both design and construction phases. Competing stakeholder objectives to limit these disruptions must be weighed against the need to mitigate risks and to produce a constructible, operable and maintainable end product. Perhaps the approach we should take with stakeholders, also known as Authorities Having Jurisdiction (AHJs), is sharing memorable case studies that bring to life the potential risks so often buried within lengthy risk registers. This paper provides a sobering case study describing what can occur if the presence and/or location of utilities and other obstructions are not fully understood due to restrictions placed on exploration or mining operations. In this instance, the Microtunnel Tunnel Boring Machine (MTBM) encountered a buried concrete structure, followed by rows of abandoned wood piles, before finally colliding with an active high-pressure gas main under a bustling coastal highway. Multiple stakeholders imposed tight logistical and other work restrictions, compounding the difficulties experienced during the drive. However, the difficulties were effectively managed through the project team’s proactive collaboration and communication with everyone involved. INTRODUCTION Some of the most important decisions that influence the ultimate success or failure of a project may not be made by design engineers. Instead, these decisions are often made by project stakeholders and third-party agencies. Tasked with protecting the best interests of their users, these agencies are cautious of potential impacts associated with project construction and subsequent use. Unfortunately, actions required (or restricted) by stakeholders often result in unwanted ripple effects that negatively affect the very users they are trying to protect. For example, a mandate limiting a shaft site to an unreasonable size may be intended to reduce local business impacts, but may actually increase impacts as more supply and truck hauling is required."

Jan 1, 2016

By Charles W. Huggins

Knoop hardness indentations were studied and measured with the electron microscope on TiB2, HfC, and A1B12 crystals. A detailed description of replicating the indentations using collodion and Faxfilm is made. A John Hopkins grating having 28,800 lines per inch was used to accurately determine the magnification used on the electron microscope. The primary objectives were to prepare carbon replicas of hardness indentations, to measure the indenations accurately, and to compare the results with those obtained with the light microscope. The resulting data showed excellent agreement between the measurements made on the replicas with the electron microscope and those made with the optical microscope. The replicas made from collodion showed slightly better agreement with the light optical values than did the replicas made from Faxfilm.

Jan 1, 1963

By D Laurence

Australians are at the forefront of exporting their mining expertise in a number of areas. Minerals education is just one example. The growing economies of Southeast Asia host some of the most prospective mineral fields in the world. Laos for example, hosts the world class Sepon and Phu Kham copper-gold deposits. The Philippines has the fifth largest global mineral resource inventory. These and other countries in the region lack the mining engineers, geologists and metallurgists required by international mining companies to ensure their operations are sustainable. This paper describes the author’s experience in working with mining schools in Southeast Asia and specifically the Philippines, Cambodia, Laos, Thailand and Vietnam. Various strategies to ensure sustainability and lessons learnt are presented.

Nov 22, 2011

By T. Harrison

Surface coal mines in West Virginia are receiving stringent NPDES discharge limits for total recoverable selenium. With limits in the low parts-per-billion range, selection and implementation of proper sample collection and analytical methods are imperative for quality assurance and control and for consistency in results. Given the typical oxidized form of selenium in the water, the low limits and the large and variable flow rates from the watersheds, end-of-pipe treatment is difficult and cost-prohibitive to implement. Discharge locations in the remote and steep terrain exacerbate the problem. To evaluate options for end-of-pipe treatment at a Patriot Coal Corporation surface mining operation in West Virginia, CH2M HILL performed wastewater characterization for a range of key constituents and selenium species at three outfalls for selection and preliminary sizing of appropriate treatment processes. A preliminary evaluation of base and wet-weather flows was done to understand flow variability considerations for discharges. A conceptual evaluation of technologies to treat selenium to permitted levels was conducted in con-junction with order-of-magnitude life-cycle cost estimates.

Jan 1, 2010

By Albert Stazicker

AT Climax the warehouse department operates as an independent unit similar to the mine and mill departments. It has the responsibility of receiving, checking, unloading, and storing all material and supplies delivered to the plant. In addition, the transportation of all supplies comes under the direction of the warehouse so that prompt delivery of supplies to all departments is one of its major functions. The transportation division operates heavy and light trucks, trailers, two large tractors, and two snowplows. In addition to delivering supplies it is also responsible for snow removal from the roads, hauling of sand and gravel for concrete and domestic coal to employees. and all miscellaneous work involving the use of tractors or trucks.

Jan 1, 1946

By John J. Henn

Ten proposed processes for the recovery of manganese from domestic resources as a high-grade oxide product are described. Nine of the processes employ sulfur dioxide, sulfuric acid, or a combination of both for leaching. The tenth process utilizes sulfur dioxide to sulfatize the ore at 600° to 850°C before water leaching. In addiction to these ten complete processes, six processes from the patent literature are described. Methods for receovering MnSO4?H2O are also reviewed.

Jan 1, 1968

By G. France

The Blair Athol Coal Mine (BAC) is a large open cut operation in the Bowen Basin of Queensland, Australia. Current mine capacity is about 11 million tonnes per annum (Mtpa) of export coal. On-line analysis at BAC consists of two Coalscan 9500s installed directly on the output of the crusher plant and immediately before the product stockpiles, while a third Coalscan 9500 is installed on the transfer conveyor feeding the train loading bin. The two product Coals cans have a dual purpose. The first is to provide real time coal quality data directly back to the mining operations. The second is that of modeling the product stockpile with accurate on-line information. This modeling enables both production and coal quality personnel to accurately examine the coal quality of each stockpile with a degree of resolution which previously had never been achieved.

Jan 1, 1999

By D. N. Trerice

The Electric Power Research Institute (EPRI) is sponsoring the construction and operation of a coal cleaning test facility at Homer City, Pennsylvania. The facility represents a major investment by the electric utility industry to advance the state of the art of conventional coal cleaning technology. The facility is unique in design and can process large quantities of coal in conventional flowsheet configurations, simulate full size plant conditions, and perform open and closed loop performance testing on conventional and advanced coal cleaning equipment. Computer operation will also be demonstrated. The facility objectives, initial complement, and operating plane are discussed as they relate to other coal cleaning projects at EPRI.

Jan 1, 1981