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By Richard M. Michaels

In considering the use of underground space for civil works functions, there are several criteria that must be met if transfer of any of them is to occur. It is important to recognize that these criteria involve social and political as well as conventional engineering and economic considerations. It is the purpose of this report to identify certain of these criteria and develop a set of measures that will permit the evaluation of the potential benefit of transferring civil works functions underground. The work reported here was completed for the ASCE and is contained in the report, Undergound Space, 1973. If one examines the total direct and indirect economic return from the location of civil works in subsurface rather than surface space, sizeable benefits accrue. This occurs largely because design, construction, operating and maintenance costs of these systems are highly dependent upon the forces exerted on these systems by the surface enviroment itself. Transferring of these facilities to underground space would eliminate a large segment of those costs. It is equally true that civil works functions compete with other uses for surface space and generate significant conflicts with these competing uses. Highway construction takes land from other productive uses. Electrical transmission lines conflict in terms of safety and aesthetics with adjacent social activities. Assuming that construction costs can be made equivalent, the analyses in the previous report indicate that the locating of all civil works functions underground would yield an annual net savings to the society of the order of 60 billion dollars. It may be added that the benefits in terms of improved social perfromance would also be substantial. However, it is clear that the benefits from utilization of subsurface

Jan 1, 1974

By M. E. Gershon

Software for coal blending has gained a lot of recent attention as micro-computer programs have come on the market. Some of this software is appropriate and some is not. This paper looks at the types of models being used and points out the strengths and weaknesses of each. Recommendations are then made concerning the level of detail required for these programs, relating this concern to the various ways in which coal companies are using these programs. A checklist of company requirements for these programs and available pro-gram-features provides an aid in matching the program to the company.

Jan 1, 1988

By D. Randall Crooke, Ron R. Jorgenson

Many coal combustion products (CCPs) have historically been unsuitable for placement as mine backfill because of their physical and geochemical properties and/or regulatory status. However, innovations in paste production and transport of CCPs utilizing the high, fine particle contents of these fine-grained waste materials and their water retention colloidal properties produce a non-segregating, self-cementing material that may be environmentally suitable for placement as mine backfill. Both industry and the regulatory agencies are enthused by the possible cost reductions, both in design and construction of disposal sites, and the reduced environmental impacts of CCP realized by implementation of this new use/disposal technology.

Jan 1, 2001

By Michael Brittan

The AARL elution process has recently been introduced to the North American mining industry by Bateman Engineers Inc. The process is described along with its noteworthy features. Design and operating considerations are discussed.

Jan 1, 1998

Adequate ventilation of coal mine working faces is the single most important technique for controlling respirable dust and methane. Choosing the right technique presents some tough questions. Bureau research has shown that to control respirable dust you must contain the dust near the face, keeping rollback (turbulence) to a minimum. For methane the most effective approach has been to use a blowing brattice or tubing and to create turbulence and disperse the face methane, allowing it to pass over the machine and into the return. It is immediately apparent that the two approaches may counteract one another, thus complicating the decision as to which system may be best for a given situation. At present, Bureau research has developed two successful machine-mounted face ventilation systems to meet these different needs and allow deeper cutting. The fan-powered dust scrubber is designed to control dust primarily associated with blowing face ventilation systems. The spray fan controls methane on exhaust-ventilated sections.

Jan 1, 1988

By R. S. Scheetz

The search for a more effective means of coping with methane liberation has resulted in the expanded use of seam degasification. Its advantages are measured not only in reducing the hazards due to methane, but also in producing a marketable commodity: .the gas, itself. However, the success of a methane drainage system is the culmination of many complex factors, the most important being the coal seam permeability. The two most popular drainage techniques used mining today are the vertically simulated borehole method and the in-seam horizontal borehole method. The objective of this paper is to determine the permeability range in which the selection of the degasification technique is based primarily on equipment and economic analysis. A discussion of the equipment involved will be incorporated into examples evaluated by the Penn State coal methane simulation model.

Jan 1, 1989

By Wang Xifu, Zhang Daxian, Zhang Youdi

In mine haulage system, the surge bunker or stockpile installed between two facilities can raise the system production capacity. The arrangement of surge bunker has great relation with the capability development of the whole haulage system and the economic benifit. In the haulage system, surge bunker plays a role of surge capacity, accident capacity and technology capacity. In this paper, the variation of the material in surge bunker is analysed while the mine haulage system is working, the calculation method of the whole output is raised. With the goal of the maximum system output, the method of deciding the rational size of surge bunker is put out. In case study, the system output in Huolinhe surface mine is calculated, thus the rational size of surge bunker in huaulage system is decided.

Jan 1, 1996

By Ray Soper

Important progress has been made in developing the K-Process as an alternative to cyanide as a method of recovering gold from ores and other materials.

Jan 1, 1998

By Andy J. Robinson, Mark D. Claassen

Railroad companies and transit authorities have been slow to acknowledge that for many—utility crossings, a direct pipe installation below live rail can be just as effective as a more intrusive traditional cased crossing. Properly designed and specified pipe jacking work, and specifically pressure-balanced microtunneling, coupled with careful specification and analysis of geotechnical monitoring and, where necessary, ground improvement measures, can produce a low-risk, low ground movement solution to the needs of utility companies and municipalities whose services need to pass below urban and rural rail corridors. This paper discusses the design, geotechnical and ground improvement aspects of microtunnel crossings below active heavy and light rail lines and crossings beneath active subway tunnels.

Jan 1, 2003

By Guy G. Jr. Granger

INTRODUCTION Due to the current depressed state of the mining industry, many mining companies have been forced to operate at less than maximum capacity. This paper will describe how the AMAX Henderson Molybdenum Mine and Mill near Empire and Parshall, Colorado respectively have utilized operations scheduling and budgeting to achieve production targets at minimum operating costs The AMAX Henderson Molybdenum Mine and Mill have been operating most recently at approximately sixty percent of maximum capacity. OPERATIONS SCHEDULING Production Targets. The production targets are tons, operating days, tons per opera- ting day, head grade, recovery, and pounds of molybdenum. One specific objective of operations scheduling is to meet the production target for pounds of molybdenum. Present market conditions dictate that production be adjusted to match sales of molybdenum. Over-production and creation of molybdenum inventories is unacceptable. In summary, the product ion target for pounds of molybdenum must be met, but not exceeded. Capacity. The AMAX Henderson Mill single stage open crushing circuit capacity is 48,000 dry short tons per day. The AMAX Henderson Mill single stage semi-autogenous primary grinding mill circuit capacity is 38,000 dry short tons per day. All other AMAX Henderson Mi 11 circuits such as rougher flotation, regrind, cleaner flotation, lead leach, filtering, drying and concentrate handling are sized to accommodate the 38,000 dry short tons per day and pro- ducts from same. The tailing delivery system is designed to accommodate tailing from a 38,000 dry short tons per day operation. Constraints. One mill production scheduling constraint is that the mill operating schedule must be the same as mine production, ore haulage and crushing. There is a total crushed ore stockpi1e storage capacity of 240,000 dry short tons. This breaks down to 60,000 dry short tons of crushed ore over the three reclaim pan feeders for each of the four primary grinding mill circuits. However, there is only approximately 10,000 dry short tons of live crushed ore available over the three reclaim pan feeders for each of the four primary grinding mill circuits. Dozers must be utilized to re- claim and push the other crushed ore. Primary grinding mill throughput is

Jan 1, 1986

By James L. Hendrix, David Castillo

Cyanidation is one of the most common practices used in the extraction of gold and silver. One method of application is heap or dump leaching which entails the leaching of the gold or silver ore by spraying or dripping a cyanide lixiviant over the ore and collecting the effluent. The ore is placed on what is known as a leach pad system. A typical leach pad system consists of a foundation, a leakaqe detection system, a liner, and a cover layer (Strachan and van Zyl, 1988). There are many types of liners available for use. The type of liner depends upon what type leaching pad system us used. Generally, leaching pad systems can be categorized into two types: an expandable pad and a reusable pad. An expandable pad exposes the liner to the elements only in the initial stages of ore placement on the leach pad system. A reusable pad exposes the liner to the elements on a periodic basis. In addition to the exposure to the elements, the liner is also under the stress of the ore placed on it and the stress of the vehicular traffic across it. These stresses and exposure to the elements are the major causes of liner failures, which can appear as punctures, tears, cracks, and deterioration. Because of the possibility of the failure of the pads to contain cyanide-laden solutions the designs for liners of pads and ponds have become more and more stringent. Currently, though, there is some recognition that in some locales such stringent design criteria may not be required (Chatwin, 1989). Some soils have significant cyanide attenuation and degradation capacity. It has been found that soils containing carbon- aceous materia1 wi11 remove cyanide from solutions percolating through them (Chatwin, 1989). Of course metallurgists have long recognized the deleterious effect of carbonaceous material in the mill circuit. Sheridan, et a1 (1988) have shown that WAD cyanide is detected in the effluent of a 2 m column filled with ground carbonaceous ore only after it had been continuously washed with greater than 9 pore volumes of NaCN solution. It was decided to examine the potential of successfully attenuating cyanide by placing an organic material layer between a 1iner and the prepared soil base. One consideration for the selection of the organic material was cost. Sawmill wastes, ground agricultural wastes (such as corn cobs), and other organic wastes were considered. But the first waste to be tested was a product found at any metropolitan area, sewage sludge.

Jan 1, 1990

By W. Burger

For the development of deep hard rock mines fast access to the orebody is critical. In some cases the mineralized area is more than 1500 m (5000 ft) below surface. Excavation of shafts or declines is typically on the critical path of the project schedule. Saving time on those activities can significantly increase the net present value of the mining project. Mechanical excavation methods are a step-change in excavation performance and labor safety compared to drill and blast operations. In hard rock conditions roadheaders can not be used effectively, so disc cutting is the first choice. For excavation of declines tunnel boring machines (TBM) can be used in many cases. These provide in certain rock conditions considerably higher production rates compared to drill and blast excavation.

Jan 1, 2010

By T. F. Torries

The primary criteria used by the mining industry to judge the merit of a project is internal rate of return (IRR) rather than net present value (NPV), although NPV is favored by academicians. This paper discusses the problems of IRR and NPV and compares the multigoal nature of the decision¬makers and their need for informa¬tion having the characteristics of NPV and IRR. The conclusions reached are that both NPV and IRR can be used for investment ranking, that NPV suffers the same multiple root problem as does IRR, and the use of conventional incremental IRR to reach NPV¬consistent project ranking is mis¬leading.

Jan 1, 1999

By K. D. Allen, M. J. Blattman

The problem of measuring the amount of rock removed during a given time interval is faced by most mining operations. Many methods have been developed with varying degrees of success, dependent upon the mining method and the availability of usable data. The Rosebud Mine has been in production for nearly two years, employing several techniques to estimate monthly production from underground production stopes. The use of three-dimensional solids generated from survey data has greatly improved the reliability and confidence of monthly production reports. The authors will summarize the methodology currently being utilized at Rosebud.

Jan 1, 1999

By R. Svensson

Mill linings play an important role in all comminution processes with tumbling mills. The selection of the lining profile and the lining material has a great impact on overall grinding cost and mill throughput. The cost of the lining itself is minor in comparison with media cost, energy cost and the value of the material produced in the mill. The total scope must be considered when mill linings are selected. This paper presents case stories and explains the technology behind: - Different lining profiles in rubber and steel. - Orebed magnetic lining. - Steel-cap rubber lining.

Jan 1, 1995

By Luis Tavares Ribeiro

Dynamic programming is based on the-, application of a simple property formulated by Bellman in his principle of optimality (Bellman, 1957): "An optimal policy has the property that whatever the initial state and initial decision are, the-remaining decisions must constitute an optimal policy with regard to the state resulting from the first decision". The method is charaterised by: (Dowd, 1979) a) A function defining the total value at each decision time of the system. b) The set of permissible decisions. c) The present state of the system. d) The number of steps remaining before the procedure is terminated.

Jan 1, 1982

By Donald E. Scheck, Syed F. Abbas

Public domain ventilation simulation programs have been well accepted by the mining engineers, but preparing the input and interpreting the results are labor intensive tasks. High performance personal computers and versatile CAD packages provide the means to quickly create the network and display the results. The enhanced simulators work from computerized as-mined map, the projected mine layout and timing maps. Using on screen displays of these maps and the snap-on feature of AutoCAD, the planner designates nodes in the ventilation network, connects them into branches and selects the branch characteristics from a side bar menu. The color coded ventilation network appears with the parameters shown along each branch. The software then calculates the length of airways and computes the branch resistances where needed and converts the input into the required format and passes the data to the Pennsylvania State University or U.S. Bureau of Mines ventilation programs. Output is available in graphical as well as report format. The color coded graphs include pressures at the nodes and flow quantities on the branches. Since the networks come from the mine maps, the ventilation displays are to scale and can be plotted separately or superimposed on the mine maps.

Jan 1, 1991

By James A. Jones

The Doe Run Co. emerged from the depressed lead market of the mid-1980s as North America's leading lead producer. Doe Run was lean and mean but quickly recognized that technology had advanced while the company was held to the belt tightening slump. With the 1990s approaching, Doe Run moved quickly to update its technology and control equipment to ensure its position as an industry leader. Doe Run was formed in 1986 when Fluor Corp. and Homestake Mining Co. combined their lead-zinc-copper assets in Missouri to form a joint venture. Doe Run is now owned by Fluor Corp. A rich history of mining, milling and smelting started in Missouri in 1862 when the St. Joseph Lead Co. was founded. Subsequent acquisitions led to the formation of St. Joe Minerals, which was later purchased by Fluor Corp. Six mines, four concentrators and two smelters are presently being operated, and a secondary lead smelter was recently commissioned. The Viburnum, Buick and Fletcher operations are lead, zinc and copper flotation concentrators, while the Brushy Creek plant is set up to process high copper-low lead ores. This article looks primarily at the process control installation at the Fletcher concentrator.

Jan 1, 1991

By C. L. Schaidle

Computers and communications technology have revolutionized many industries. In earthmoving, this revolution has just begun. The major changes are still to come but are just around the corner. This article presents a vision of this upcoming revolution in the earthmoving industry. This vision includes basic communication, machine monitoring and diagnostics, job and business management, planning and operations, and machine control. For the industry to realize maximum benefits from the information age, it must have a vision of the future that is shared by technologists, machinery producers and miners. History of the information age During the 1970s, the information age revolutionized retailing, starting with the grocery business. By using bar codes and laser scanners, individual items were connected to the information world of computers and communications. Once this connection was made, the data on what an item was and where and when it moved became valuable information for inventory control and marketing. Not only was the information valuable, it was easy and inexpensive to collect and manipulate. The effort required to provide the consumer with the right product at the right time was reduced. Costs went down and customer satisfaction went up. But there were casualties of this revolution. Many inventory counters lost their jobs. There were also equipment casualties. Cash registers that could not interface with the digital world were discarded long before the end of their useful life.

Jan 1, 1994

By Armstrong

This is a world of change and has been from the beginning. There are constant efforts on the part of natural forces to wear down the high spots and fill in the low spots. Wind and water over eons of time tunnel through obstacles and build windways and waterways to make movement of air and water easier and more efficient. It is a natural, never ending, ever changing continuing effort. Man in his struggle to survive, and to progress, has had to adapt the terrain of the earth to fit his needs the best he could. First, he used natural caves to protect him from the elements; then he learned how to build earth and rock-moving tools from antlers, bone, rocks, and sticks and adapted his cave to increase his security and provide better protection from heat and cold and from his predatory enemies. As his numbers increased, so did the necessity of further adapting his environment to accommodate his needs. Water was usually not available when and where needed, especially in the desert areas where civilization developed, and long tunnels were drilled to intercept ground waters and lead them to underground caves carved out of soft limestone. Most of the tunnels of early man were to bring water from where it was to where man needed it. Then, as now, as man increased his chances for physical survival, he turned to the quality of life -- and this reflected in the concern for life after death. This lead to the elaborate shafts and tunnels for the protection and prservation of the more affluent noblemen and pharaohs of the early Egyptian civilization. Man used the underground for the stable temperature and for protection and safety.

Jan 1, 1974