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By Donald J. Olson, Thomas J. Lutzenberger, John Ramage

The North Shore Inline Interceptor, Phase IA tunnel is a 8,550-meter (28,000-ft) interceptor tunnel currently being constructed by Traylor Bros./Frontier-Kemper, Joint Venture, using a 9.8-meter (32-ft - 4-in) diameter Robbins tunnel boring machine (TBM). This tunnel is being driven in Silurian age dolomite approximately 91.5 m (300 ft) below ground surface. Significant water inflows were encountered when the tunnel drive penetrated the thinly-bedded Waubakee Formation. Flow increases approaching 0.75 cu m per min per 30 m of tunnel (200 gpm per 100 ft) have occurred in this formation. After driving approximately 2,285 m (7,500 ft) of tunnel (200 m full face in the Waubakee Formation), total flows exceeded 12 cu m per min (3,200 gpm) with about 5.7 cu m per min (1,500 gpm) entering the tun¬nel from the 200 m (600 ft) of exposed Waubakee Formation. Additional water control measures consisting of increased pumping capacity, increased water treatment capacity, surface grouting ahead of the tunnel, grouting ahead of the tunnel face and panning to improve the working environment for installation of tunnel support, were implemented to deal with the large water inflows. Currently (January 24, 1989), 3,400 m (11,000 ft) of tunnel has been driven, total water inflows are in the range of 11.7 cu m per min (3,100 gpm) with only 6.8 cu m per min (1,800 gpm) inflow from about 1,220 m (4,000 ft) of tunnel driven full face through the Waubakee Formation.

Jan 1, 1989

By Gregg Sherry, Bob Gordan

INTRODUCTION This paper report presents the general case history for the construction of the North Outfall Replacement Sewer (NORS) project. A 1982 City of Los Angeles Wastewater Facilities Plan recognized that a 19.3 km (12¬mile) section of the North Outfall Sewer (NOS), from Culver City to the Hyperion Treatment Plant, was deteriorating and had insufficient capacity. Built in the 1920s of unreinforced concrete and lined with vitreous clay tiles, the originally unventilated NOS suffered considerable corrosion by H2S gas. This caused roof tile and concrete to fall to the bottom of the pipe, which, over the years, reduced the 11.9 M3/S (420 cubic feet per second (cfs)) design capacity of the NOS to a current level of approximately 8.5 M3/S (300 cfs). This worsening condition, thereby contributing to the polluting of Santa Monica Bay. This situation culminated in the State of California Regional Water Quality Control Board, Los Angeles Region, issuing a Cease and Desist Order on January 27, 1986, which required the City of Los Angeles to eliminate such dry weather overflows through a number of prescribed actions. One of these was to construct the North Outfall Replacement Sewer (NORS) by April 1, 1993. PROJECT DESCRIPTION The NORS Project involved the construction of over eight miles of tunnel and related structures. It consisted of a main tunnel conduit to convey sewage to the Hyperion Treatment Plant and four diversion lines connecting the main tunnel to major existing

Jan 1, 1993

By Michael McNinch, LaTasha R. Swanson, Jennica L. Bellanca, Justin Helton

As manufacturers and mine operators develop and implement proximity detection systems (PDSs), they need to be mindful of the systems’ compatibility with mineworkers’ tasks, and possible unintended consequences. Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) interviewed mineworkers at mine sites that currently use or previously have used PDSs on mobile equipment, including shuttle cars, battery haulers and scoops. Mineworkers reported that mobile PDSs affect loading, tramming, section setup, maintenance and general work on the section. Mineworkers discussed the operational effects and increased burden, exposure and risk. Mineworkers also suggested that improved system task compatibility, training, logistics and PDS performance might help address these issues. Manufacturers and mine operators implementing this or similar technologies may also consider mitigating task incompatibilities up front, performing additional site-specific usability testing and restricting the use cases of the system to improve performance.

By A. J. S. Spearing, T. Kostecki, D. Benton

The use of paste backfill in room-and-pillar coal mines in the United States needs to be fully investigated. This paper discusses a series of physical tests that were conducted to examine the support benefits of theoretical paste backfill regimens in Illinois Basin room-and-pillar coal mines, which necessarily included consideration of weak floor conditions. The series of tests included those simulating strong floor conditions, weak floor conditions, under-confined scenarios, and testing of actual coal-based paste backfill samples. The testing indicated that a paste backfill regimen utilizing a minimum backfill strength of 22 psi at a minimum fill height of 50% of pillar height could significantly increase the longterm stability of coal pillars in the Illinois Basin. Considering typical coal wash plant recoveries, 50% fill would be feasible.

Jan 1, 2014

By Aaron Archer, James Parkes

This paper presents design considerations for the major underground elements of the pending BCRUA Phase 2 Raw Water Delivery System Project. These elements include two Lake Taps; an 8,800 LF, minimum 10-ft OD intake tunnel; a suction chamber with 6 Pump Shafts; a 30-ft diameter, 300-ft deep Main Shaft; a 2,600 LF Transmission Tunnel with 78-inch steel liner; and a 130-ft deep shaft on the Transmission Tunnel. The tunnels and shafts will be excavated through the Glen Rose limestone. The design development included consideration for technical requirements, easements, third party commitments, previous local project experience, and constructability based on contractor outreach.

Jun 13, 2021

By John J. Sammarco, Alan G. Mayton, Elaine N. Rubinstein

Researchers from the U.S. National Institute for Occupational Safety and Health (NIOSH) developed the Saturn light that significantly improves illumination for roof-bolting machine operators while reducing glare. The existing roof-bolter lighting was the baseline and was compared to the Saturn at 100, 75 and 50 percent intensities. Discomfort glare and disability glare were measured by the De Boer rating scale and the Mars Letter Contrast sensitivity test, respectively. Thirty study participants were tested. Discomfort glare was reduced at least three levels with the Saturn luminaire. Visibility levels were four to 6.5 times better with the Saturn than with the baseline. The Saturn design is freely available for commercialization.

By C. H. Smith

The present interest in beryllium seems to be the result of recent developments in the uses for the metal discovery of significant deposits of disseminated beryllium ores, and the development of chemical and physical processing techniques, for recovering the beryllium values contained in these ores. At the present time most of the new and potential uses for beryllium are in the research stage of development and are not consuming large quantities of the metal. However, they do point to an expanding market. Interesting new discoveries or extensions of previously known deposits have been reported during the past year from the Boomer Mine in Colorado, the Mesquite area of Nevada,, the Chemalloy pegmatites in Canada, the Brazilian and African pegmatite districts and from other areas, However, this paper will discuss only four of the beryllium deposits, which appear to be of special significance due to their; large reserves of ore and promise economic development. The new chemical and physical processing techniques are not discussed in detail, but it should be stressed that the development of an economical process to handle the pegmatitic and low-grade non-pegmatitic beryllium ores is of great importance to the development of the beryllium industry. Scientists in both government and industry are co-operating in this effort and it is expected that commercial processes will be developed in the near future.

Jan 1, 1962

By Panshi Xie, Yingyi Zhang, JIANJIE DUAN, Shenghu Luo

The most important safety aspect associated with great mining height in steeply dipping coal seam mining is the stability and control of the roof. When soft coal and hard gangue make up the immediate roof of a working face, the soft-coal interlayer plays a significant role in gangue damage and can cause problems such as roof collapse in front of the support, collapse of partial area supports and other problems that can affect the stability of the supports and the surrounding rock system. This study found that the first weighting step of a multigangue roof is larger than that of a nongangue roof, but periodic weighting steps are similar. The overburden collapse height is lower in a multigangue roof than in a nongangue roof due to the buffering and supporting function of the collapsed gangue. Failure of the coal interlayer is the key factor in the collapse of multilayer gangue. The limited load of the interlayer and maximum resistance of the support is concluded by the hard gangue and soft coal interlayer mechanical model. The maximum resistance of the support increased with the dip angle of the seam and burial depth. Certain measures are proposed to control the stability of the gangue roof, including zoning control of the mining height and resistance and advancing the support while maintaining roof contact, thus ensuring the integrity of the support and surrounding rock system.

By RENE GOMEZ, RAUL CASTRO

Estimation tools and models are now available to estimate fragmentation, but some variables have yet to be studied to understand their effect on the fragmentation process. One such variable whose mechanisms have yet to be studied is the residence time, which in block caving directly depends on the distance that fragments travel from their original position in the broken ore to the drawpoint. In this study, granular material fragmentation was characterized during its flow to understand its characteristics and mechanisms. The results show that the breakage of fragment singularities occurred mainly within medium and smaller sizes, increasing fine material during flow. Thus, the main fragmentation mechanism in experiments was identified as abrasion between rock fragments where fine material continuously increases as distance increases in spite of the high rock strength and the piston flow movement used. The results presented here can be applied to incorporate fragmentation during flow of large travel distance of ore such as in block caving.

By Gordon M. Pugh, David G. Rasmussen

INTRODUCTION Sublevel long-hole stoping is a large tonnage stoping method that may be used when there is a fairly com¬petent straight vein and the walls will stand with little support. It is a method that lends itself to a high degree of mechanization. Two variations of the method are illustrated in Figs. 1 and 2. Fig. 1 illustrates development typical for a 3-m (10-ft) wide vein. Initial development is by a lower haulageway, which may be either track or trackless. A two-compartment raise is driven in the footwall of the vein. At about 12 m (40 ft) above the main head¬ing, a footwall scram is driven and pockets through the vein are cut on 7.6-m (25-ft) centers. Each of the sub¬level blocks selected in this example is 45.7 m (150 ft) long by 12 m (40 ft) high. Stoping starts at the slot raises at stope endlines and retreats to the timbered raise. This retreat sequence starts on the lowest sublevel and the opening cut is blasted into the slot raise. This retreating system is used in order to provide a good safe back over the miners working in any given sublevel. A crawler-mounted down-the-hole or conventional pneumatic drill puts the holes down from one sublevel to the next on any desired drill pattern. Gravity flow brings the broken ore down to the scram level. The illustration shows a large slusher mounted at the timbered raise and slushing from the pockets back to the raise chute. Development of the ore block in Fig. 2 is typical for a 5.5-m (18-ft) wide vein. Initial development is by a trackless heading driven in the footwall of the vein. Pockets are then put into and through the vein on 7.6-m (25-ft) centers. For ease in using trackless rubber tired mucking equipment, these pockets are crosscut to the vein at approximately 1.04 rad (60°) rather than per¬pendicular. A two-compartment timbered raise is driven down from one level to the next. Endline slot raises are again put through from level to level. Each of the sub¬level blocks selected in this example is 40-m (130 ft) long by 33.5 m (110 ft) high. Stoping starts at the slot raises and retreats back to the timbered raise. Long holes are drilled from one sub¬level down to the next by starting between the lowest pair of sublevels and then working up the ore block. Mucking out of the pocket drawpoints is accomplished by rubber-tired load-haul-dump (LHD) units which then dump into a centrally located orepass.

Jan 1, 1982

By B. G. McNish

Neutron Activator Laboratory Analyzer used for Rapid Analysis for Ore Blending, Stripping, and Mine Control BAUXITE is a rock and not a mineral. Since it is a rock, its mineral content varies depending upon the parent material, the topographic location of the deposit and the severity of the weathering and oxidation processes which produced it. At Bauxite, Arkansas the major mineralogical constituent of the bauxite is gibbsite with ~IL- purities of silica, iron oxide, and titania minerals. Minor amounts of other minerals are found. Chemical composition varies from 45% to 60% alumina, 5% to 25% silica, 1% to 15% ferric oxide, and 1% to 3% titania. The Arkansas bauxite region is located entirely within the north- central area of the West Gulf Coastal Plain near the northwestern boundary with the Interior Highlands. The region trends northeast-southwest and is about 42 kilometers long. It is divided into two districts; one in Saline County and the other in Pulaski County. The Saline District is the most important since it has produced most of the bauxite. This district is located at Bauxite, Arkansas and the deposits are found around the flanks of the Saline Dome. It is roughly square-shaped and is about 190 square kilometers in area. The source rock for the deposits is a Late Cretaceous, grey, nepheline syenite.

Jan 1, 1979

By E. J. Onuscheck

With passage of the Federal coal' Mine Health and Safety Act of 1969, many challenges have been directed to the industry's mining and safety engineers. The most critical challenge is that of ventilation. The language concerning ventilation in many sections of the Act could very well deprive or limit the mining engineer in planning the ventilation for new mines, since the Act requires federal approval of all ventilation plans. Dependent upon approval and of course application of the law, this could, due to economics, prohibit the opening of new mines in some cases. Petitions for modification of some mandatory standards relating to ventilation have already been filed under Section 301(c). It is quite possible that many of these standards may be modified.

Jan 1, 1970

By Karin Bäppler

"When considering large-scale infrastructure projects worldwide special attention has to be paid to the large diameter tunnel construction projects that were successfully completed in the Southern Hemisphere. The projects that are highlighted in this paper are large-scale infrastructure projects in the sector of transport. In focus are four road tunnel projects that were constructed in Australia and New Zealand using mechanized tunnelling technology. The tunnel boring machines (TBMs) that were reliably applied to these four major projects all exceed the bore diameter of 12 meters. These TBMs are therefore in the range of large to very large diameter TBMs. The technology used demonstrates state of the art technology with tailored tunnelling technology adapted to the specific project demands. Two Double Shielded Hard Rock TBMs (Ø 12.35 meters) were used for the construction of the Clem Jones Tunnel in Brisbane crossing beneath the Brisbane River and these two machines have been reused for the excavation of a 4.3km long two-lane highway tunnel for Legacy Way in Brisbane creating a new traffic artery towards the city centre. Two EPB Shields (Ø 12.48 meters) excavated and lined the twin-tube road tunnel for the Brisbane Airport Link. Excavation diameters in excess of 14 meters, such as the Earth Pressure Balance Shield (Ø 14.41 meters) involved in the Waterview Connection Project in New Zealand, are understood in the tunnelling industry as very large diameters. The machine is customized to the requirements and subsurface conditions of Auckland. The paper spotlights the large to very large diameter TBMs that were used and focuses on the comprehensive solutions developed by the machine manufacturer to provide a system with benefits for the contractor especially for the Waterview Project. INTRODUCTION Extensive large-scale road infrastructure projects like the ones implemented in Brisbane (Australia) and currently under construction in Auckland (New Zealand) show the tendency of today’s infrastructure construction projects. Functional infrastructures need to be put in place to cope with the demand of mobility and flexibility of people living in cities and metropolises. Impact during construction work to people or environment has to be kept as low as possible to ensure the quality of life is not disrupted."

Jan 1, 2016

The successful exploration for Austin Taylor and Gen. McRae from 1931 to 1940 obscured the fact that I was reaching a period of transition. This was true both in personal and business life. It was probably fortunate that I did not realize how great a change must come after I passed the age of 50. In the personal life of our family the change came when both our children left home to go to school or college. This made home a different place and, because of the absence of the children, Dorothy could devote much of her time and attention to the art she loved so well. She could spend long periods in New York, the center of the nation's art life. Vacations at Tahoe and long pleasure trips made the separation from the children less disturbing but it could never again be the same as it had been in the first 20 years of our marriage. The change In my business life was just as complete, though a little more gradual. While work for Bralorne and General McRae made the "bite" of the Great Depression less painful for us than it was for most consultants and their families, the fact that I was getting older made a new sort of work inevitable. I was 50 years old and the total grew rapidly. Planes and automobiles that made travel easier even in the wilds of Alaska and northern Canada still made it possible for me to look at new prospects, but increasingly often I was exhausted at the end of a day's climb and, if the nature of my work did not change there would soon be no more work. Fortunately work of a new sort came a little at a time. As I became a director of Bralorne and president of its American subsidiaries I had to take on more administrative work, and success of these operations made others want to employ me to help direct policy and value mines. I was also asked to arbitrate contests between mines when technical disagreements were so great that judges or juries could obviously not understand them My consulting for government agencies helped to

Jan 1, 1976

By Hamed Khodadadi, Hamid Ghadiri

The ball mill grinding circuit has widespread application in mining, metallurgy, chemistry, pharmacy and research. It faces some challenges because a grinding circuit is a multivariable system in which high interaction between loops, variation of system parameters with time, and time delays are problems. In this study, a fuzzy logic self-tuning proportional–integral–derivative (FLST-PID) controller based on an improved disturbance observer is designed for control of ball mill grinding circuits. It is combined with an improved disturbance observer (IDOB) to eliminate system interaction, attenuate internal and external disturbances and compensate the effect of system uncertainty on the performance of the ball mill grinding circuit.

By Jay F. Colinet

Coal workers’ pneumoconiosis (CWP), commonly known as black lung, is caused by the inhalation of respirable coal mine dust and is a disabling and potentially fatal lung disease with no cure. Historically, CWP has taken a tremendous human and financial toll on the U.S. coal mining industry. Recent health surveillance data indicate that CWP continues to occur at elevated levels. Respirable coal dust exposure must be controlled to prevent the development of CWP. The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducts laboratory and mine-site research to identify control technologies that can be used to successfully reduce respirable dust levels. Various technologies, using multiple methods of control, can be applied to reduce dust levels. An overview of CWP’s impact and a general methodology for controlling respirable dust in underground coal mines are discussed in this paper.

By David J. Hammel

This chapter will summarize some of the important applications in the geotechnical (pit slope, spoil pile and tailings stability, and hydrology), the environmental (including reclamation), and equipment selection and analysis areas. Virtually all aspects discussed are applicable both for planning of new mines and for evaluating existing operations. Probably the most influential item which has affected the areas discussed in this chapter and possibly most areas discussed in this book is and will continue to be, in the next decade, the myriad federal and state environmental, safety, and reclamation regulations affecting new mine development and continued operation of existing properties. Computer applications have been and will continue to be instrumental in assisting in planning to meet the challenges of the requirements dictated by these regulations.

Jan 1, 1979

By Brian E. Davies, Bobby G. Wixson

INTRODUCTION The mining, extraction and refining of metals into useful materials is an honorable profession with an ancient and productive history. Civilizations have long depended upon metals for their implements, structures and machinery necessary for survival, growth, and development. Today, as in the future, metals and minerals are essential to the progress of mankind as we approach the 21st century with technologies and concepts that will require new concepts and production from the metal mining and processing industries. Today is the tomorrow we talked about yesterday and the implementation of new ideas is essential if we are to achieve "Frontier Technology in Mineral Processing". Unfortunately, the state-of-the-art mining, processing, smelting and refining methods historically employed were less than desirable environmentally, which has caused todays public to view the metal mining and processing industry with concern. Presently the ancient rock and chat tips connected with old Roman lead-zinc mines which were worked in Wales are causing stream contamination problems that must be corrected at considerable expense to the local governmental agencies (Firth, J.N.M., et al., 1981). However, improved progress has been made and the environmental control and clean-up procedures utilized by modern lead-zinc operations in the "Viburnum Trend" or "New Lead Belt" of South East Missouri may serve as a model to illustrate how alternative technologies, environmental concerns and cooperative efforts contribute to efficient mineral production within the confines of a U.S. National Forest region without significant environmental impacts. This area received international attention when it was opened within the boundaries of the Clark National Forest in the mid 1960's. By 1970 it ranked first in the world by producing 432,576 short tons of lead ore and has since continued in this position producing 451,153 short tons of lead ore in 1983 representing 91% of the total United States lead production (U.S. Bureau of idines, 1983). This production comes from a mining area approximately 40 miles long by 10 miles wide extending in a north-south direction. Geologically the lead is disseminated throughout the Cambrain age Bonneterre Formation, mostly a dolomite, at depths ranging from 700 to 1200 ft. (213.4 to 365.8 m). Galena (lead) is the principal ore mined with lesser quantities of sphalerite (zinc), chaleopyrite (copper) and silver being recovered as economic co-products. This new mining development in one of Missouri is most scenic areas could have led to a classic confrontation between industries and environmentalists. Instead, through the cooperation of industries, governmental agencies and university researchers, the Ozark environment has been protected, and may serve as a model for future coexistence of the mineral industry with the environment. Cooperative Program Development As early as 1965 five new mines and two lead smelters were being prepared for production and environmental concern was an essential part of that planning. All the mining companies became acquainted with representatives of the various federal and state agencies and scientists from the University of Missouri-Rolla (UMR). During the next six years, St. Joe Minerals Corporation, American Metal Climax, Inc., Cominco American Incorporated, Ozark Lead Company (Kennecott) and American Smelting and Refining Company participated in cooperative research efforts. The companies also participated in information exchange meetings, the development of improved analytical methods and the utilization of research findings in the modification or construction of pollution-abatement facilities. Early on research was carried out to determine background values and to establish natural baselines of trace metals in the surrounding environment. The unusual topography and drainage pattern of the mining area were helpful since it was possible to establish control sites and test sites below individual mine-mill operations to study waste-water effects on the receiving streams. The location of the ‘New Lead Belt', mines, mills,

Jan 1, 1985

By J. C. Agarwal

Major scientific discoveries cannot be programmed. New or frontier technology, however, can and should be planned. It is the vital force underlying the business strategy of a vigorous and profitable mining and metals company. Generally, a radical departure from existing technology is required to 1) Enhance the competitive value of ore reserves, i.e., to turn low grade or marginal reserves into competitive reserves. 2) To increase yield and decrease costs. 3) To decrease investment. 4) To increase mine life. 5) To improve product quality to meet market demands. The very definition of frontier technology implies that it is so different that the old plant, if already in use, will not be directly suitable to use the new technology. Therefore, a priori, we know that the commercialization of frontier technology would very likely involve new investment. The recommended technique of economic and technical analyses, I propose to call "Success Analysis.'' Simply stated, it forces us, by step- by-step procedure, to ask "what is needed to succeed in this particular project." Therefore, the first step is to identify what is meant by "success." The definition of "success" requires an agreement with top management or sponsors of the project as to what constitutes "success" in their minds as contrast to the technical people perception of "success." In general, top management would define success as meeting: 1) The technical objectives, i.e., technology being developed would produce the desired product at the acceptable quality. 2) Financial objectives, i.e., when commercialized, the project's capital cost, operating costs and return on investment are better than the projects they would normally fund. The return has to be better because new technology is inherently riskier. 3) Marketing objectives in that the project will produce product of acceptable quality in timely manner, i.e., scale-up to commercial plant would not cause undue delays in start-up and that large fix-up expenditure would not be required to protect the projected return on the investment. Many projects are started in the laboratory to develop "Frontier Technology" in mineral processing. Most of these efforts are never commercialized. There are many causes of these failures. The major causes are listed below: 1) Inadequate communication with the sponsors of the project so that project objectives are defined and agreed to by all. 2) Ill-defined technical problems. 3) Incomplete development of technology. This has two major components: a. Incorrect scale-up and engineering. b. Inadequate start-up and maintenance planning. 4) Incomplete and over-optimistic process economics. 5) Lack of understanding of the future behavior of the marketplace. 6) Failure to complete R&D effort by the time it is needed. 7) Incorrect projections of human resources required; that is, technical, managerial and operating. 8) Lack of realistic forecast of the expenditures required for commercialization of the R&D effort. These pitfalls can be avoided by comprehensive planning and the use of success analysis technique. The major elements in "Success Analysis" are: 1) Identification of the "need" for new technology. 2) Unbiased and complete scale-up engineering. 3) Acceptable economic feasibility with enough margin of error in the sale prices and operating costs to justify the inherent risks in frontier technology. 4) Timing for availability of investment capital and markets. Many failures in the development of frontier technology are preordained because the initial selection of the research project has been without adequate attention to the needs of the industry. Many very innovative hydrometallurgical processes for recovery of copper from concentrates were developed in the past twenty years. They have not adapted except to a very minor extent because they did not satisfy the success analysis criteria. The copper industry in North America needed a process to compete against high grade ores and to avoid

Jan 1, 1985

By R. L. Weigel

As Florida phosphate mining gradually moves from the Bone Valley formation to the Hawthorn formation, a greater portion of the minable deposit contains dolomitic diluents which result in lower product grades that can be detrimental to the production of phosphoric acid for fertilizer uses. One beneficiation technique found applicable to the phosphate pebble size range (3 X 16 mesh) is heavy media separation using suspensions of magnetite and ferrosilicon. As part of an ongoing investigation of dolomite removal technology, a pilot heavy media cyclone system was constructed by IMC and used in the testing of a variety of drill core composites and hulk samples. The results of these tests were used to develop a predictive model for heavy media cyclone separation based on pebble fraction assays and heavy media operating parameters. This model is currently being used in the evaluation of specific future mining areas.

Jan 1, 1984