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By Robert A. Pond

Heavy (exceeding 35 tons) roadheaders have not seen much use in the United States, but are used extensively in Europe to excavate many types of underground openings in civil and mining applications. Early models of roadheaders were light and suitable only for utility excavation such as drift enlargement or chamber excavation, unless the ground was very soft and easily cuttable. Frontier-Kemper Constructors, Inc. is now using a 45-ton roadheader to excavate two mine slopes in Kentucky and a 70-ton roadheader to excavate a long decline at a new mine in Utah. Results to date indicate that heavy roadhead machines are an effective alternative to both conventional excavation and full-face boring machines in many cases; and where circumstances are favorable are a superior choice. This paper concentrates on applications in the mine development construction industry, but the conclusions are no less valid for civil construction.

Jan 1, 1983

By S. Saeb, C. Francke

Introduction Although mining in one form or another has existed for millennia, the use of numerical methods for mine design is a relatively recent development. The basic physics that control the behavior of rock or soil have been known for centuries, but it wasn’t until the last half of the twentieth century that analytical methods that could accurately predict the behavior of a large, irregular rock mass were developed. Before the advent of modern computers combined with differential and integral analytical methods, numerical methods available to mining engineers were limited to closed form solutions for simple excavation geometries. Today, mine-scale three-dimensional stress analyses can be performed on a relatively inexpensive personal computer. Many of the recent advances in rock mechanics modeling are the result of research funded as part of nuclear waste repositories around the world. The large scale exacting performance requirements of waste repositories are frequently very different from traditional rock mechanics projects. These facilities are designed and built under tighter control and scrutiny because of the potential hazards they present to the public. Therefore, a great deal of research towards advancing rock mechanics and numerical modeling resulted from these projects. Much of the repository research is applicable to commercial mines. The advances in modeling programs have been paralleled by advances in computer equipment. Today, a moderately equipped personal computer can handle most mine geomechanical modeling projects in a reasonable period of time. While the learning curve varies, an engineer with modeling experience can develop a medium sized model in a few days. The relatively low investment cost of geomechanical modeling today makes it accessible to most mining operations. The benefits of a solid geomechanical modeling program include reduced operating costs, improved safety, and reduced design costs.

Jan 1, 2007

By Betty Gibbs

The Ore Body Modeling and Mine Planning Worshop, sponsored by the Society for Mining, Metallurgy, and Exploration, Inc. (SME), was held Feb. 22-24, 1991 before the SME Annual Meeting and Exhibit in Denver, CO. More than 40 people from mining companies, government agencies and universities attended. Eight vendors of integrated ore body modeling and mine planning software attended and presented the results of problem sets given before and during the workshop. They were: [ ]

Jan 1, 1991

By Z. Mullard

The introduction of social media platforms has ushered in a new era of interaction and information exchange, which impact business-to-society relationships. Mining companies are closely watching these platforms, as the industry takes a cautious approach to control flows of information. This paper explores the risks, challenges and opportunities of using social media, based on a qualitative mixed methods investigation with stakeholders from the Canadian mining industry. Generational and language barriers, misunderstanding and limited motivation from regulators make implementing social media platforms challenging and risky at an organizational level. The benefits of social media include being able to mobilize communities and share information in real time. Despite the challenges, the study found that 62% of mining stakeholders are incorporating social media tools, mostly in an ad hoc manner. Flexible strategies for transparent communication and public engagement are creating new opportunities for information exchange.

Jan 1, 2011

By William Connell

NFPA 502, Standard for Road Tunnels, Bridges and Other Limited Access Highways establishes minimum fire protection and fire life safety requirements for road tunnels, bridges and other roadways where access by emergency responders is physically limited. The 2008 edition of NFPA 502 represents the Technical Committee?s consensus of current best practice for fire protection and life safety requirements for road tunnels, bridges and similarly limited access highways. Research of national and international test programs, design guidelines and regulating standards was per-formed and considered in an effort to establish a singular, comprehensive document representing a recognized base threshold of fire safety in these type facilities. This paper provides an overview of the more significant revisions including the application of fixed fire suppression systems, guidance on tenable environment, protection of structure and dangerous goods transport.

Jan 1, 2008

By E. Jackson

This paper describes highlights of the Placer Dome MiniMole project - the development and testing of a robotic machine for mining narrow ore veins. A prototype hydraulically controlled robotic machine was built and tested. The machine provided a platform for testing numerous cutters in the field. Other cutters, e.g. undercutting devices, were tested in the lab. Extensive analyses were done on specific energies and cutter penetration. Three sets of quarry trials were done, then the machine was tested in an underground mine. Rock UCS values varied from 180 MPa to 230 MPa. The paper includes lessons learned and recommendations based on the project findings.

Jan 1, 2007

By Thomas C. Shapiro

This is the final article in a three-part series on microcomputers and application software in the mineral industry. The first article covered microcomputer terms and concepts. The second discussed exploration and mining software. This article will examine plant, administrative, and geotechnical software. Every effort has been made to be current in the latest software developments. Rapid change, however, is a fact of life in the computer world and any omission is inadvertent. Introduction Geotechnical disciplines have received considerable attention in software programming. Calculations are repetitive and the formulas needed to solve them are not extremely complicated. These programs are ideally suited to the microcomputer and the microcomputer is ideally suited to the consulting geologist or engineer, due to its low cost and reliability. In fact, the advent of the Apple (a registered trademark of Apple Computer Inc.) and, more recently, the IBM personal computer has caused an explosion of inexpensive software programs available to the microcomputing public. Another area that has benefited from computerization, although not in the same way, has been mineral beneficiation. Here, process control for start-up or phase-down operations has been used in newer plants for some time. Programs to perform various calculations are becoming more common as micros increase in number. Tappi Journal has a section with solutions to handheld-calculator and microcomputer problems. Process Modeling Most process modeling is still done only on mainframes. One such program is called ASPEN PLUS (a registered trademark of Aspen Technology), and a one-week course is recommended so the user can best use the program. This program is available through timesharing from University Computing Co. Programs to find an optimal solution using Linear Programming (LP) have been around for some time. Also, plant process simulation has been possible using simulation programs. Both simulation and LP are expensive to program and run. Although there are LP programs available for some micros, the user must be fairly knowledgeable about how to set up the problem. This is because each problem must be set up as a unique program that typically requires custom programming. There are some programs that can handle blending of mine crudes and examine economic parameters over the life of the mine. Plant Applications Areas relating to mine and plant applications with programs available for micros are maintenance, production reporting, inventory, accounting, and personnel scheduling. Maintenance Maintenance typically requires that certain jobs be performed in a particular sequence and parts be ordered with enough lead time for maintenance to take place on time. There is, therefore, a critical sequence of tasks that must be performed or the scheduled maintenance will not take place. Two answers needed for maintenance project scheduling are: what is the lead time needed

Jan 4, 1984

By Wern-Ping Nick Chen

Durability risks for underground facilities can be underestimated during design phase as compared to well-known geological risks. However, unclear durability requirements can result in construction schedule delay and change orders. Unlike bridges or buildings, a unified underground durability code or standard does not exist. This paper will provide a durability approach for underground facilities, including degradation modes, mitigations, and compliance measures during construction. In addition, this paper will address how to clearly specify durability requirements in a contract document to reduce disputes during construction and discuss key durability tests that are time consuming and will impact construction schedule if not timely planned.

Jun 23, 2024

By R. L. Guerguerian

Critical fasteners are described as they apply to the specification, manufacture, and assembly on large grinding mill bolted joints. The importance of adequate design methods, related joint diagrams and pivot analyses, and special emphasis on the quality of manufacturing and the tightening procedures in the field, are discussed; all in an effort to ensure high availability plant operation.

Jan 1, 2001

By G. T. Adel, J. D. Miller, C. L. Lin

Washability analysis determines the maximum separation efficiency that can be achieved in the operation of coal preparation plants. Unfortunately, there are no on-line techniques for determining this most fundamental information. It now appears possible to determine coal washability on-line through the use of x-ray computed tomography (CT) analysis. This paper presents the results for the development of a CT-based, on-line coal washability analyzer. The development of appropriate hardware and software necessary to adapt a CT analyzer for use in determining coal washability is discussed. Testing of the analyzer using well-characterized coal samples is presented.

Jan 1, 2000

By M. C. Mound, E. Gallestey, C. Colbert

Continuous operating performance and high profit is one of the major concerns in the mining industry. Information systems are expected to reinforce and enable conformance to these requirements. The companion efforts of business management and production information systems press for tighter integration to avoid over-laps, multiple instances of similar data, and expensive maintenance of databases. Implementation of advanced intelligent systems throughout a mine operation can reduce costs, optimize investment and create a shorter payback via conversion of the data accumulated by field and process devices into information, and subsequently, into decisions. However, in order to harness the potential power inherent in these intelligent devices, adequate and flexible modular knowledge-based solutions are required. Fortunately, there has been at least one such practical response to this challenge, namely the ABB IndustrialIT portfolio. With these tools in place, production efficiency is reached via integration of process, production, and quality information. Moreover, they permit immediate detection and remedial action to changes to process and boundary condition variables. Finally, using advanced optimization techniques supported by dedicated mathematical models, they allow for economic process optimization (process set points and coordination thereof, energy management, production planning, energy supply contract optimization, etc) of the plant as a whole.

Jan 1, 2004

By A. Yazadni-Chamzini

Maintenance strategy selection plays a significant role in mining design. The nature of maintenance strategy selection is a complex multi-criteria decision making (MCDM) problem including both tangible and intangible parameters which are often in conflicting with each other. Moreover, when decision makers are uncertain in determining and defining the ratings and the weights of alternatives and criteria respectively, fuzzy theory provides an appropriate tool to handle the existing uncertainties. In this paper, a new fuzzy MCDM method based on the concepts of TOPSIS and AHP was proposed to evaluate the feasible maintenance strategy. The linguistic terms are employed to assess the ratings and weights. Fuzzy AHP is utilized to calculate the weights of the evaluation criteria; then, the rankings of alternatives are computed based on fuzzy sets theory and TOPSIS. A real world case study is presented to illustrate a potential application of the proposed model.

Jan 1, 2012

Using a series-model of an automotive short range radar sensor (SRR) and a recently completed experimental radar system, field tests have been performed in a surface mine. It was examined, to what extent low-cost electronically scanning radar sensors can provide useful data for assistance systems on large scale mining machines. Simple sensors are useful for anti-collision safety zones or hopper car automation. The more complex and sophisticated experimental radar system using digital beam-forming can clearly detect and map the contours of trenches and slopes. The overall promising results refer to many more potential applications for electronically scanning radar in surface and underground mining as a reliable alternative to mechanical laser scanners.

Jan 1, 2007

Although out of the ordinary, MINING ENGINEERING is pleased to present a few photographs that typify Western US mining activity during WWII. The photographs, taken by R.G. Zellers at Colorado mining operations between 1942 and 1946, were primarily intended for equipment manufacturers. The pictures capture scenes of hardworking miners during a time when output was essential to fuel a wartime effort. In addition to providing a rare opportunity to step back 40 years and view the equipment and activity common at the time, Zellers' skill with photo composition and his ability to obtain clarity in dimly lit underground operations gives viewers an acute awareness of the dampness and dirt of the mines, and a sense for the miners' limited working space.

Jan 6, 1983

By Hans Hamrin

Three drill-blast cycles of 3.1 m advance achieved in one working shift of 7.5 hours at the Holsfjorden Tunnel project in Norway. The tunnel, 5235 m long, with a cross section of 8.6 m2, was completed several months ahead of schedule. This remarkable performance was achieved by a crew of 16 men, using machines specially designed for small tunnel excavation. The integration of drilling and charging into one unit, mucking and transport in another, reduced non-productive time considerably. The average cycle time of 140 min made it possible to complete three rounds in one 7.5 hours shift.

Jan 1, 1987

By A. D. Davis

The Gilt Edge Superfund Site is a former heap-leach gold mine that currently is being remediated in the Black Hills of South Dakota. Mine runoff water is treated before release from the site. The field pH, before treatment, is about 3, and the water contains arsenic and some heavy metals, in addition to sulfate concentrations of about 1400 to 1500 mg/L. In the Keystone area of the Black Hills, naturally occurring arsenic has been detected in ground-water samples from wells. Keystone City Well #4, which is not used currently, showed arsenic concentrations of 36 parts per billion (ppb) and sulfate concentrations of about 19 mg/L. With field samples of water from these sites, a limestone-based method was successful in reducing arsenic and heavy metals concentrations. The results are significant because previous research with the limestone-based method mainly had involved samples prepared with distilled water in the laboratory, in which interference of other ions such as sulfate did not occur. The research indicates the potential for broader field applications of the limestone-based removal method.

Jan 1, 2011

By T. R. Ellis

Minerals Appraisers/Valuers often find great difficulty or failure in attempting to employ the Sales Comparison Approach to the Market Value Appraisal of development and operating stage mineral properties. An important factor generally overlooked is a comparison of net operating income (NOI) margins on a per-unit-of-production basis between mineral properties, whether these be demonstrated or forecast margins. NOI margins can vary greatly between mines or quarries that are producing similar products. Ultimately, the expected NOI margin determines what a buyer is willing to pay for an income producing property. Common criticisms of the sales comparison approach by minerals appraisers are introduced. These are counterbalanced by raising some issues in the way the inputs for the Income Approach are usually derived by minerals appraisers, and by review of some conspicuous examples of the much too common misuse or abuse of the income approach in market value minerals appraisals. Example transaction analyses and sales comparison analyses are used to demonstrate the author?s methodology for adjusting units of resource in his transaction adjustment tables (see APPENDIX). The examples are used as the basis for discussion of ways to employ adjustments for operating economics and many other factors, while cautioning about the potential for double counting. The conclusions include a recommendation that minerals appraisers attempt to apply at least two of the three valuation approaches when appraising the market or fair value of development and operating stage mineral properties, the two being the sales comparison and income approaches.

Jan 1, 2011

By Tom Szaraz

Part of a major sewer expansion for the City of Columbus, Ohio. The Big Walnut Outfall Augmentation Sewer?Part II (BWOAS) consists of 13,200 feet of tunnel of 12-foot tunnel passing mainly through glacial deposits with a water head of up to 2 bar. A Lovat RME167SE was used to drive this tunnel with steel fiber reinforced precast segmental liner used for support. This paper will discuss the concepts for tunnel sup-port and TBM selection, the problems encountered with the TBM sealing systems and the solutions used to repair the machine.

By D. Kruse

Top down constructed large diameter (up to 90 m [300 ft]) shaft design and constructability issues present an interesting suite of challenges and opportunities highlighted in this paper. The study covers 2D and 3D finite element models used to: analyze various failure modes, evaluate the shaft liner and internal structures? response to seismic loading, assist in segment design, and assess final structural design tradeoffs. Efforts to achieve economic advantage over conventional heavy civil practices have prompted innovative solutions for ring and segment design, ring build assembly, and annulus backfill grouting. Intended for soft ground conditions, relationships between soil parameters and structure design are also explored.

Jan 1, 2011

By R. E. Mclvor

This is an update of an original dissertation on this topic by Lavallee, McIvor and Stolovitch (1992). A step-by-step, technical procedure used to measure and improve the performance of plant grinding circuits was adapted into a training program. ?Systematic Design of Instruction? was applied to: ? Determine if training was a suitable way to deliver this new technology; ? Define the technical content of the program; ? Select program specifications based on learner and context characteristics; ? Design, create and test prototypes of the training modules; and, ? Establish a process for plant implementation. The training program covers numerous skills that are extremely valuable for plant personnel, not only in the grinding area, but also for many other parts of the plant. This paper describes how new skills are brought into the workplace through designed instruction can be an effective alternative to hiring during severe skilled labor shortages.

Jan 1, 2008