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By Ralbern H. Murray

Typical First Year Selling Price Strip Mined Western Sub-Bituminous Coal Based [Fixed Capital (1) $600 MM Construction Loan Interest $100 Working Capital $ 30 Start-up Costs $ 30 Total Capital Requirement $760 MM Annual Costs (First Year) $M/Year Coal (2) 443,550 Operating Costs(3) 53,000 Depreciation(4) 36,500 Interest(5) 45,220 After Tax Profit(6) 34, 200 Federal Income Tax (48% Rate) 31, 570 Gross Revenue Required 245,040 (Less) By-Product Sales (18, 000) Net Revenue Required 227, 040]

Jan 1, 1975

By John M. Marek, David E. Nicholas

INTRODUCTION The purpose of this article is to outline the data requirements for selecting a proper underground mining method and to discuss the general steps taken in selecting that method. Determining the appropriate mining method is an iterative process that continues throughout the life of a mineral deposit. We will discuss the subject from the standpoint of a feasibility study, where a realistic assessment is necessary in order to determine investment merit. The feasibility stage of a project is that point where the drilling program has defined sufficient geologic reserves to consider mining the deposit but little or no underground development has been done. Primary parameters for consideration in choosing a mining method are 1) geometry of the deposit; 2) distribution of grade; 3) rock mass strength for the deposit, as well as the hanging wall and footwall; 4) mining cost and capitalization requirements; 5) mining rate; 6) type and availability of labor; 7) environmental considerations; and 8) other site-specific conditions. Of these parameters, the first four have the most impact on determining the general mining method to be employed.

Jan 1, 1981

By John W. Harshbarger

The Upper Santa Cruz Groundwater Basin lies in the drainage area of the Santa Cruz River in Arizona, and extends upstream from the community of Rillito to the international boundary, see Figure 1. The principal water use area lies between and includes the cities of Tucson and Nogales. A subsurface geologic barrier near Rillito provides a reasonable dividing line between the groundwaters of the Upper and Lower Santa Cruz Basins. The Upper Basin contains the Tucson and Sahuarita-Continental critical ground- water areas. The Tucson Water Use Area encompasses the Tucson metropolitan area and extends from the northern boundary of the Basin south to the boundary between the Tucson and Sahuarita- Continental critical groundwater areas near San Xavier. The San Xavier Use Area is the San Xavier Indian Reservation. The north and south boundaries of the Continental Use Area coincide with the limits of the Sahuarita-Continental critical groundwater area. The first study of groundwater in this valley was initiated by Dr. G. E. P. Smith in 1905 and the results were published in 1910, followed by a series of bulletins of the Arizona Agricultural Experiment Station, University of Arizona, covering the general field of groundwater development and utilization. Beginning in 1939, the Ground Water Branch of the United States Geologic Survey, in cooperation with the Arizona State Land Department and the Arizona Water Commission (AWC), have published a series of bulletins concerning groundwater occurrence and utilization in various areas of the state. In 1975 and 1977, the AWC published the "Arizona State Water Plan" (1), comprising a detailed inventory of water availability and use in the State of Arizona, and a study of alternative futures.

Jan 1, 1979

By Milos Krofta, Donald B. Aulenbach, James P. Van Dyke

INTRODUCTION An innovative Ø.1-MGD (378.5-m3/day) biological and phyicochemical wastewater treatment system at Hancock, Massachusetts, USA, has been treating the domestic sewage generated from the four-season Jiminy Peak timeshare resort since 1985. The influent raw sewage is collected and equalized in an equalization tank, then biologically treated by two rotating biological contactors (RBC). A portion of the RBC effluent is discharged to a secondary sedimentation tank to simulate conventional waste treatment by a conventional RBC system. For parallel treatment the remaining portion of the RBC effluent is discharged to an innovative Sandfloat (SASF-8) clarifier to simulate a two-stage biological and physicochemical treatment by RBC-Sandfloat. Both secondary sedimentation effluent and Saandfloat effluent are later combined together and discharged to a tertiary sand filter and two UV disinfection'units for final polishing. The operation and performance data of Jiminy Peak plant in the period of May 1985 to March 1988 was fully documented in the Lenox Institute technical report No. LIR/Ø3-88/292 (391 pages, March 1988). This report presents only background information and complete plant data in the period of April 1988 to January 1989. Dr. Lawrence K. Wang and Mr. James P. Van Dyke have been the Consulting Engineer and Director of Special Projects, respectively, for the Jiminy Peak Project since 1985. (Key Words) Innovative and Alternative Technology, Rotating Biological Contactor, Sandfloat, Dissolved Air Flotation, Sedimentation, Tertiary Filtration, Ultraviolet, Disinfection. BACKGROUND INFORMATION Jimmy Peak, Inc., Hancock, Massachusetts, has designed and constructed a secondary wastewater treatment system consisting of preliminary/primary treatment facilities, two rotating biological contactors, a dissolved air flotation clarifier, a secondary sedimentation clarifier, a sand filter and two ultraviolet (UV) disinfection units. Total average wastewater flow is approximately Ø.1 ) (378.5 cubic meters per day). In accordance with the Consulting Engineer's preliminary design, the total wastewater stream is initially collected and equalized by an equalization tank, and then biologically treated by rotating biological contactors (RBC). Part of the RBC effluent is diverted to a Krofta Sandfloat (SASF-8) for physicochemical clarification in order to simulate an innovative RBC-Sandfloat two-stage waste treatment system. The remaining part of the RBC effluent is diverted to a sedimentation tank for secondary clarification in order to siumulate a conventional secondary RBC-sedimentation waste treatment system for the purpose of parallel comparison. Both Sandfloat effluent and sedimentation effluent are later combined together and discharged to the subsequent sand filter and UV disinfection unit for final polishing. Figure 1 shows the flow diagram of Jiminy Peak Plant. The Massachusetts Clean Waters Act (M.G.L.c.2l,s.26-53) was amended by Chapter 246 of the Acts of 1973 to authorize the Massachusetts Department of Environmental Quality Engineering (DEQE), Division of water Pollution Control, Boston, Massachusetts, to regulate discharges into all waters of the Commonwealth of Massachusetts, including groundwaters. The DEQE regulates discharges through the issuance of discharge permits which impose limitations on the amount of pollutants which may be discharged in the effluent, together with monitoring and reporting requirements and other conditions to insure adequate treatment of all liquid wastes prior to discharge. The DEQE reviewed the application submitted on behalf of Jiminy Peak, Inc. for a permit to discharge sanitary wastes from the Jiminy Peak secondary wastewater treatment system located off Brodie Mountain Road, Hancock, Massachusetts, and subsequently developed the conditions contained in the Groundwater Discharge Permit No. Ø-188. More specifically, Jiminy Peak, Inc. (i.e. the permittee) has been authorized to discharge into the ground from the Jimmy Peak secondary wastewater treatment facilities for which the Permit No. Ø-188 was issued, a treated effluent

Jan 1, 1989

By William P. Shinn

The site of Pittsburg from the first knowledge by white men of its location has been regarded as a position of great strategic importance.

By Erik Marsh, Frederick C. Harris Jr., Javad Sattarvand, Joshua Dahl, Alireza Kamran Pishhesari

Based on the mine safety and health administration (MSHA)reports, mining truck accidents are among the significant causes of fatalities in the mining industry. The major causes of haulage accidents can be divided into non-driving and driving factors, such as truck-related sudden failures and operator performance. Numerous parameters affect trucks' safe operation, but situational awareness plays a significant role. Due to the distinct structure of mining trucks, making them efficient for mining purposes, the operator has a very limited field of view (FOV), making them prone to accidents resulting in losing lives. The cabin's position blocks the truck's right and rear sides, creating several blind points around it. Aiming to test/train the operator's awareness of the surrounding, a proximity detection system is developed through a multiplayer virtual reality (VR) application to investigate the human factor in equipment collisions. The operators were examined and monitored when asked to conduct what exactly happened in the Marigold mine truck accident without being aware of the scenario. After receiving sound, vibration, and visual alarm warnings, their reaction and performance were analyzed. The platform is developed using the Unity game engine for HTC VIVE virtual reality goggles. An Omni-direction treadmill and a motion simulator platform are utilized for the player and dump truck operators. Fifteen students were monitored when driving the dump truck receiving/not receiving proximity detection alarms. None of them repeated the accident when receiving proximity alarms. Also, they found the visual alarm the most comfortable while driving the truck.

Jun 25, 2023

By Steve Karl, Rock Jenkins

The mining industry appears to be slowly rebounding. But many individuals and company officials are still smarting from the beating they received during the recent recession. As a result, companies have taken the "lean and mean" approach. As pointed out at the Oct. 24-26, 1984 SME-AIME Fall Meeting in Denver, CO, companies are placing more emphasis on optimizing their operations through more efficient mining and processing technologies and equipment. Empathizing with the mining industry's woes was the meeting's welcoming luncheon speaker, John D. Withrow, Jr., executive vice president product development for Chrysler Corp. Withrow paralleled Chrysler's problems of a few years ago with the current problems facing the US mining industry. He said Chrysler's come-back centered around its engineering and technical personnel, who regained "their seat at the head table." "In short," Withrow said, "we had lost the competitive edge. By cutting costs and people and improving our products we got everybody to believe we could." The 2700 participants at the Fall Meeting attended technical sessions geared toward turning mining back into a productive and profitable industry. Sessions and symposia included papers on precious metals extraction, crushing and grinding innovations, geomechanics, environmental control, health and safety, and various commodities. This article briefly highlights some of the papers presented. To order preprints of these technical papers, see ME, December 1984, pages 1620 and 1621. Computers Gain Mining Acceptance High tech has reached mining. As evidenced by many papers, computers have become valuable tools in many applications. These include tailings ponds operation and waste management; truck dispatching; mine design, simulation, and scheduling; monitoring; and reclamation. Mine planning is generally labor intensive and requires a considerable amount of the planner's time. P. K. Chatterjee, X. Chung, and Y. Jianjy described a computer-generated interactive graphics approach to under-ground coal mine planning that lessens the manhours involved in producing plans. The computer program examined exploratory borehole information. This included coal seam thickness, tonnage, quality constraints, and the nature of their distribution. Layout designs were then initiated and a probabilistic simulation performed to determine production levels of different extraction strategies. The interactive graphics approach gives planners the ability to quickly evaluate several layout alternatives and select the best one. For surface coal mines, M. A. White, of Arch Minerals Corp., explained several computer programs that aided in his company's surface mine plans. Several drill hole database and modeling pack¬ages are available. But Arch tech¬nicians developed specific pro¬grams for model strip areas. They were used to form long-term pro¬jections for various area and semi¬area stripping operations. They also generated reports on yard¬age, tonnage, quality, and ratio in¬formation. The information is used in budgeting, to compare mine plans, and to analyze acqui¬sition candidates. While computer-based truck dispatching systems have been used in mining for some time, earlier systems were run on ex¬pensive mainframe or high per¬formance minicomputers. As such, computer-based truck dis¬patching systems have been too expensive for all but the largest mines. Recently, however, a microcomputer-based system, af¬fordable to smaller mine opera¬tors, has become technologically feasible. Y. C. Kim and W. E. Kolb re¬ported on a simulated microcom¬puter system that uses strategi¬cally placed signposts in the pit area to automatically detect truck movements. A microprocessor in the signpost sends information to the microcomputer. The computer determines the truck's assign¬ment and alerts the dispatcher. He radios the driver his assign¬ment. In addition to the technical pa¬pers, an introductory short course on microcomputers was offered at the meeting. L. M. Kass and J. P. Stone, from the US Bureau of Mines, walked participants through the uses of microcom-

Jan 1, 1985

By Allen J. Sobczak, Peter J. Peters

The five tunnel contracts of Milwaukee Northeast Side Relief Sewer System are about 80 percent complete. The tunnels are all excavated for 1.9 meter (6'-0") finish diameter sewers in a variable rock, mixed face, and glacial soil environment. Different contracts were let under two primary types of specifications, performance and prescriptive, which treated aspects of construction, such as primary ground support and groundwater control, differently. Interfacing of design and construction through field personnel allowed the needs of all parties to be met and resulted in savings in time and money to the Milwaukee Metropolitan Sewerage District (MMSD). Interfacing, cooperation and risk sharing allowed resolution of problems such as line and grade variations and potential differing site conditions. It also allowed the parties to pursue constructive changes to construction activities. Thus on one contract prescribed use of compressed air was eliminated, but migration of fines into the tunnels was stopped with filter fabric. Use of an expensive primary support system was dropped, but concern about deterioration of lagging was alleviated by use of special materials.

Jan 1, 1983

By Dale A. Shay, Roy R. Cellan

The Santa Fe Mine, located in west central Nevada, began leaching ore in 1988 and completed ore processing in 1995. Homestake Mining Company has completed final reclamation of the site, including remediation of bare surface soils resulting from the oxidation of sulfide minerals and migration of acidity in the mine waste repositories. The need to remediate oxidized sulfides and mitigate resultant acidity at the Santa Fe Mine emphasizes the economic, reclamation, and environmental advantages for understanding and pre-planning for management of potential sulfide wastes during mine planning phases. The lack of pre-planning by mining companies for sulfide waste management was common in the 1980's due primarily to mining of reserves characterized largely as oxide deposits and to the common opinion that low moisture regimes in arid or semi- arid climates would not allow for significant acid generation. Since the 1980's, operational experience has shown that sulfide wastes, deposited randomly in waste dumps and without adequate planning for final reclamation success, can create final reclamation problems that are very costly to remediate. While mine waste characterization, waste management plan compilation, and in-pit selective waste handling procedures add operational costs, the reclamation experiences at the Santa Fe Mine are indicative that pre-planning and management is worthwhile both in actual overall cost efficiency and in successful reclamation of the mine site. The reclamation program at the Santa Fe Mine shows Homestake's continued commitment to the successful management and reclamation of their mine sites.

Jan 1, 2000

By Robert A. Bauer

Two basic types of subsidence occur in Illinois: pit and sag / trough. Pits develop over mines less than 165 feet deep and where relatively incompetent strata are found over the mines. Sag subsidence is found over mines as shallow as 75 feet and more generally over mines of greater depths. The percentage of subsidence and angles of draw associated with sag subsidence appear to be controlled by the rock properties at each specific site. The percentage of subsidence and angles of draw are smaller where the sites are not affected by geologic structures. An investigation to determine if a time factor based on the time interval from the date of mining to the subsidence events has shown that simple correlations with time, percent extraction, average pillar stresses, and pillar dimensions is not evident in Illinois.

Jan 1, 1982

By Joseph Cervik

Common methods of controlling gob gas in U.S. nines are by means of ventilation of gob areas and gas drainage through surf ace boreholes. Costs of drilling surface gob holes increase as deeper coalbeds are mined. Where gob holes cannot be drilled because of topography, ventilation is the only means of control. Even then, sufficient air may not be available to dilute methane in the bleeder entries to acceptable levels. Thus, new methods of gob gas control need to be developed that are independent of surface topography, and of the mine ventilation system, and less costly than present systems. Except for slight variations in procedures and equipment, Great Britain, West Germany, France, Belguim, Poland, and Czechoslovakia use a common methane control method that is different from the system generally used in the United States, This Bureau of Mines paper reviews European mining methods, mining conditions, and methane control technology and discusses their applicability to U.S. mines.

Jan 1, 1979

By Thomas J. Martin, James W. Martin, Paul F. Martin

The conveyor belt is the basic building block of a broad range of material handling applications in modern mining systems. The mining plans and site conditions dictate basic system requirements but this is only a part of total design evaluation. The total system in the typical mining situation can encompass all the activities from the excavators at the mining face to the processing plant, site loadout facilities and/or a power plant. The number of alternative configurations which must be evaluated including subsystems and components is limited only by analytical time and creativity. The constraints and issues which must be addressed continue to expand, driven by reliability, environmental impact and cost competitiveness. All of the system requirements must be translated into specifications for costing, final design and construction.

Jan 1, 1993

By S. Rajan

Familiarity with NEMA standards and the influence of the power supply on the motor-load system permits the user to make the necessary decision as to whether a standard or special motor is needed for his particular application. This paper highlights the more important aspects of NEMA standards for ac induction motors from the application engineer's standpoint and the effect of the power supply on motor characteristics.

Jan 1, 1975

By Patrick Oriez, Chris Norris, Alain Mercusot

"Temporary mechanical ventilation is one of the fundamental requirements in guaranteeing a healthy atmosphere in underground construction works in order to protect the health of persons working on the site. It is therefore essential to conceive a system which meets the requirements of the whole of the worksite and for all phases of work which takes into account all aspects pertaining to its design, dimensioning, justification, installation, maintenance and validation. In doing so, the ventilation design and the selected apparatus to be installed shall meet with the degree of health protection and the quality of air of the worksite as defined by the legislation in force in France, through limiting the concentration of the different pollutants associated with the site activities. Consequently, when presenting a mechanical ventilation project, all of the participating parties and especially the contractor make a commitment to guarantee sufficient volumes (or airflow rates) of fresh (non-polluted and oxygenated) air and extracted (polluted) air in order to meet these limitations and maintain them in all conceivable site configurations. This article sets out the most important aspects of the implementation of a ventilation project from the initial design stage through to its application, discussing French legislation, ventilation principles, calculations and techniques with regards to underground construction sites. BASICS OF VENTILATION Mechanical ventilation studies are concerned with all of the site workstations and work phases which are sources of pollution and apply to all zones of the underground worksite with the goal of maintaining the concentration or composition of this pollution below the permitted levels and comply with the following three basic principles which are complementary to one another without being in contradiction. •,The first principle consists in eliminating or limiting as much as possible the emission of any polluting, irritant, or dangerous substances, by specifying appropriate construction techniques and equipment (use of electric motors, combustion engine equipment: filters, tanks, catalyzers, use of less polluting explosives, damping down dust with water or wetting products, damping down and diluting certain gases using water mists). •,The second principle is designed to capture residual polluting substances emitted close to the source in order to prevent them from spreading into the worksite atmosphere (extraction ventilation with ducting up to the source – upstream of the extractor fan – and use of downstream filters before expelling the polluted air to the exterior). •,The third principle involves accompanying the capture of the pollutants with additional blowing ventilation specific treatment of substances dissipated by and distant from the source of pollution (acceleration of the drift air flow in order to confine dust and better capture it, supply ventilation with ducting in order to dilute the gases emitted and discharge them to the exterior)."

Jan 1, 2016

By J. Driscoll, T. Morson, Ross M. Workman

The study investigates the effectiveness of the canopy air curtain (CAC) in reducing respirable dust exposure for shuttle car and ramcar operators in underground coal mining. Field testing showed that the CAC reduced dust exposure by 11-34% overall and by 57-65% during ramcar loading by the continuous miner. These results demonstrate the CAC’s potential as a significant dust control device.

Feb 19, 2022

By Philip-Mark Spanidis, Christos Roumpos, Francis Pavloudakis

This paper presents a quantitative research (QNR) methodology, collaboratively conducted with a group of mining experts, to assess the knowledge management (KM) landscape in the Greek mining industry. The methodology involves a framework for structured data collection using questionnaires, statistical analysis, discussion on critical methodological aspects, and interpretation of results focusing on key aspects of interest for designers of KM systems. The paper concludes by summarizing the methodology’s outcome and proposing perspectives for further research.

Aug 1, 2024

By Roy H. Paddon

This paper describes the 6, 000 tpd, three stage haulage system at the Ozark Lead Company's mine in southeastern Missouri. It details the methods and problems pertinent to the loading, hauling, sorting, crushing, storing and hoisting of waste rock and ores obtained from underground development headings and production areas. The Ozark Lead Company is a wholly owned subsidiary of the Kennecott Copper Corporation. Its mine is located nine miles south of Bunker in Reynolds County at the south end of the "New Lead Belt" mining district. Development started in May, 1964, by drilling a seven foot diameter (six foot cased), 1, 250 foot development-ventilation shaft. Drifting began in August, 1965, to obtain a bulk ore sample, to test ore continuity, and to drive two mine levels while the pre-grouted production shaft was being sunk. Over 7, 900 feet of 12 by 24 foot drifting was done from this small shaft. In March, 1966, a 20 foot diameter, three compartment, concrete lined production shaft was collared. It intersected existing development headings at a depth of 1, 195 feet in April, 1967, and was completed along with a concentrator and other facilities in June, 1968. Mine production began that month, with 5, 000 tpd reached in 1970.\

Jan 1, 1971

By H. G. Papacek

The Fabrica Mine of the Brazilian iron ore company Ferteco mines on an extremely inhomogenous ore deposit. A large amount of the crude ore consists of fines minus 100 micron which cannot be sold without further treatment because of its chemical and physical properties. In order to make full use of the mined crude ore an expansion program has been realized which incorporates among others a concentrator to produce classified blast furnace ore , sinter feed and pellet feed. The pellet feed is converted in a 2.5 million tons per year Lurgi Dravo plant into high grade pellets. The paper discusses the selection of the concentration process, the pelletizing process and describes the experiences with the operation plant during the startup and the first years of operation.

Jan 1, 1979

By Joseph M. Tarantino, Eric F. Perry, Keith B. C. Brady, Michael W. Smith

The Pennsylvania Department of Environmental Protection in 1998 reviewed its permitting process to determine how effective its program has been in preventing pollution and to identify here it could be improved. Of the 1,699 bituminous mine permits issued from 1987 to 1 996, 50 were identified to have current or past postmining discharges with water quality problems. The remaining 1,649 sites had no known current or past postmining discharges problems. The 50 sites were selected for further review. On closer examination, 33 of these permits no longer had water quality problems or the problem had not actually resulted from the permitted mining activity. Only 17 permits, or one percent of the total permits issued, were found to have caused long-term postmining discharges serious enough to require treatment and prevent bond release. Analysis of these 17 sites using current knowledge of mine drainage prediction, revealed that the most common cause of error was inadequate information in the permit application. Errors in interpretation of the application data and in implementing the permit were less common. A very small percentage of all permits issued resulted in postmining discharges for no clearly identifiable reason. Trends over the 10-year study period indicated a decreasing incidence of permits resulting in postmining discharges. Further, with the exception of the first few years of data, most of the postmining discharges were of mildly acidic or alkaline quality and amenable to passive treatment.

Jan 1, 2000

By Prakash Venkatesan, Mehmet Ali Recai Ӧnal, Shaik Saida, Veerendra Singh, Chenna Rao Borra, Manish Kumar Kar

A laboratory-scale investigation of the effect of milling operation and catalyst addition ( K2CO3) on the partial reduction of low-grade pyrolusite ore pellets was carried out using coke as a reductant. Thermogravimetric analysis was used to understand the correlation between milling and catalyst addition parameters with the reduction temperatures. DTG analysis of pyrolusite pellet reduction showed three distinctive peaks associated with a three-step reduction mechanism (i.e., MnO2→ Mn2O3→Mn3O4→MnO). The results showed that the grinding and addition of the catalyst have a significant effect on lowering the MnO2 reduction temperature independently. But maximum reduction temperature drop is obtained when combining grinding and catalyst addition in this work. By 3 h milling and 10 wt% catalyst addition, the reduction temperatures were reduced by more than 200 °C compared to the raw ore pellets. These results obtained from the DTG analysis were further supported by XRD analysis of the reduced samples.

Dec 20, 2022