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By Jun Yang, Zongshan Zou, Mei Qu, Jianjun Zuo

For technical renovation of the thermal plant, one frame structure workshop of 50,000 m2 (59,800 yd2) construction area and one reinforcement concrete chimney of 150m (492 ft) height shall be demolished by blasting at same time. The engineering environment of which is complicated and the accommodation space is limited. Therefore, the collapse sequence, direction, scope of the dismantled building must be accurately controlled to ensure the safe operation of the adjacent generator unit and transformer station. By taking technical measures of theoretical analysis and numerical simulation etc., as well as research on structures collapse method and detailed delay interval, it puts forward the technology of bidirectional folded collapse of the workshop and it uniquely adopts the initiation system that combined with “half-second delay inside drilling” and “millisecond delay outside drilling”. Additionally, by using of the integrated vibration reduction technology in combination of the blasting ruins, buffer ditch and damping ditch, it has safely accomplished the demolition blasting work in high efficiency. Besides the demolition blasting vibration signal is collected and analyzed. The success of the demolition blasting will become valuable reference to other similar works.

Jan 1, 2016

By Jon H. Gould

This paper describes the following at the new Advanced Solid Rocket Motor (ASRM) nozzle manufacturing facility, which is being constructed inside an existing manufacturing facility: 1) generalized subsurface conditions, 2) pile load test program and evaluation, 3) pile selection, 4) problems associated with pile driving operations, and 5) production pile installation. The poor subsurface conditions, known and unknown underground obstructions, and work environment inside the existing building, used to manufacture the Space Shuttle external fuel tanks, required special pile installation equipment, procedures, and work schedules to install the economical pile foundation system ahead of schedule and without a lost time accident. GEOTECHNICAL STUDIES In April and May 1990, 16 soil test borings were drilled inside the existing building with a truck-mounted drill rig. The borings extended to depths ranging from 60 to 65 ft (18.3 to 19.8 m) below the floor slab. Typically, the silty and clayey soils were sampled by pushing "undisturbed" Shelby tubes, and the more sandy soils were sampled by driving a Standard Penetration Test (SPT) split-spoon sampler. The unconfined compressive strength, water content, and unit weight of the Shelby tube samples were measured in the laboratory. A geotechnical report was issued in May 1990 presenting the results of the field and laboratory testing and foundation recommendations (Gilbert, 1990).

Jan 1, 1992

By S. Don Brown

Between 1987 and 1988, the Bureau of Mines studied the mineral resources of the White River National Forest and part of the Arapaho National Forest to appraise the resources present and to determine the types of deposits, and their location, that could be mined economically if sufficient demand and metal prices existed. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Mineral resource information indicates that in the Gore Range the area between Tennessee Pass and Gilman may contain large base-and precious-metal deposits, and could be the focus of exploration activity in the near future. The Breckenridge mining district was found to have a moderate to high likelihood for mineral exploration and possible development of gold. Recent exploration and minor development work has occurred in several other areas: Montezuma, Kokomo-Tenmile, and Upper Blue River districts, and portions of the Sawatch Range. Limestone, marble, sand and gravel, rock for crushed aggregate, and other industrial rocks have been recently mined or Quarried in the Forrest, and will likely be mined or quarried in the near future. Currently coal is being produced at one mine in the Forest, and extensive identified coal resources are located in the Forest. Parts of four known gas fields lie within the Forest west of Glenwood Springs; there is current production at one field.

Jan 1, 1990

By G. K. Rogers

The portal, which is the near-horizontal, surface point of entry to an underground excavation, can often be an exceedingly difficult area in terms of ground control. Surface and subsurface failures at portals, as discerned during a study involving over 300 case histories, are unfortunately, common. To aid in the engineering evaluation of portals, the Geomechanics Classification System was appended with discontinuity orientation assessment values and support/excavation guidelines. Also, a design model utilizing RMR predicted rock loads in conjunction with half-dome theory is proposed for the most common type of portal failure. Other pertinent comments and recommendations relating to portal stability are included.

Jan 1, 1989

By K. Viking

The vibratory characteristics of full-scale sheet piles, vibratory driven into the ground, have so far not been described systematically in detail. This paper concerns the preliminary results of a series of full-scale field tests where both the driveability and induced ground vibrations have been continuously monitored. Furthermore, the results of measured ground vibration levels have been measured at two different sites characterised as having hard and easy driving conditions. In the light of the presented results, the paper briefly discusses how the complexity of a driveability and vibration prediction can be subdivided into three parts, namely, vibrator-, sheet pile-, and soil-related parameters, all of which significantly affect both the driveability and induced ground vibrations.

Jan 1, 2000

Refractory gold ores have been the subject of intensive metallurgical study in order to achieve more efficient recovery of contained values and at the same time to minimise environmental impact. Considerable innovative gold processing technology was introduced in New Zealand last century, the most notable being the first successful commercialisation of the cyanidation process by the Crown Mines Company at Karangahake in 1889. The Karangahake gold-silver deposit was second only +to the Waihi Martha mine in total bullion production from the region with active mining from 1882 until about 1920 and sporadic production between 1930 and 1944. Reevaluation at Karangahake with associated metallurgical testing has continued since that time becoming particularly active in the last decade as a result of increasing gold prices. Gold processing technology is reviewed and results of some recent test work are presented and discussed in the context of Karangahake history and future development possibilities. This work confirms the variability and complexity of the Karangahake deposit both mineralogically and metallurgically and suggests flotation followed by new and innovative smelting is the most appropriate processing route for the recovery of gold from the high grade ore which could be produced from the Karangahake workings in moderate tonnages.

Jan 1, 1993

By AIME AIME

EITHER the 2300 people who came to the Annual Meeting were in a better frame of mind or they were resigned to their fate, or it was a better meeting than usual. Whatever the reason, at the 1nstitute?s 148th meeting the attendance was better than ever before, things went more smoothly than in some previous years, and complaints appear to have been almost entirely absent. Patience was sometimes reauired but. almost without exception, it was forthcorning the well-known recession seems to have given many members enough leisure time to come to the meeting without depriving them of the tangible wherewithal to come.

Jan 1, 1938

Kalgoorlie is the main mining centre of the Western Australian Goldfields. Its famous Golden Mile' has been noted for the exceptional width and richness of its goldtelluride lodes. Since the mid-1890s production on the major mines has been maintained practically continuously.Rich ore, though not as plentiful or as rich as formerly, is still (1948) being mined in places. Unexplored areas still remain within the main auriferous belt which offer reasonable chances of success with intensive exploration.Much detailed information has accumulated in recent years through the geological mapping of underground workings by some of the larger mining companies. The purpose of this paper is to correlate observations made in most of the accessible old and recent workings in the mines of the Lake View and Star group and elsewhere.GENERAL GEOLOGYRock TypesThe rock formations are:-1. Fine-grained (older) greenstones, locally referred to as calc schists. There were originally pillow lavas and other flow rocks of basic composition, now extensively chloritised and/or carbonated. Pillows and fragmental flow- tops are recognisable. Intercalated with flows near the top of the series are several beds of sediments.2. Graphitic slates and other more arenaceous sediments.Although referred to as slates, they are rarely more than well-bedded shales with poorly developed fracture cleavage:Thick bands of felsitic rock are found in places.

Jan 1, 1952

By Stephen C. Tadolini

PC-Strand tendons, commonly referred to as cable bolts, have become a major rock reinforcement device for underground mining and civil applications. The most common configuration is a 1+6 strand, which designates a center king-wire, with six outer wires wound around it to form a 0.6-in (15-mm) diameter cable. The capacity of this tendon approaches 30 tons, but the performance is largely dependent on the anchorage medium and the ability of the system to transfer stresses back into the rock mass while reinforcing and suspending the immediate roof. Recent developments to improve the transfer mechanisms of the PCstrand via the anchorage medium by impregnating the individual wires with uniquely designed deformations have resulted in improved anchorage and subsequent cable bolt performance. This paper describes a series of laboratory tests used to develop the initial indentation patterns and numerical modeling simulations that were undertaken to refine and optimize the final designs. The new, indented PC-Strands, offered in both bright and properly galvanized, have been tested in the field and are being used effectively in two new cable bolt products. The results of the laboratory, computer modeling, field testing and in-situ installations provide a glance at the next generation of cable bolts. This suite of testing shows how they will improve the safety and serviceability of openings under adverse ground conditions.

Jan 1, 2012

[This is the sixth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative Agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of tines of the Department of the Interior. The first report gave data on motor gasolines sold during the winter of 1935.-36.3/ The present report cover brands of gasoline represented by 1,490 samples plus thus: from the Pacific Coat, which ;sere averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were submitted. In some areas reports were received from 8 to 10 companies on the same brands of gasoline, Whereas in other areas only one Company reported on a brand. Thus, it can be seen that soma of the data are more representative than others. The inclusion of data from several cities within some of the districts has improved the report by reducing the number of brands reported by only one company. Severe changes have been made in the districts. A new district, Memphis, Tenn., has been formed to include Arkansas any western Tennessee. The Rocky Mountain area, have been divided into three sections. Salt Lake City and Denver form the Middle Rocky Mountain district; Laramie, Wyo., Idaho, Montana, and. Spokane, Wash., are included in the North Rocky Mountain district, and Arizona, New Mexico , and El Paso, Tex., have been combined to represent the South Rock Mountain district. The Cleveland district has been expanded to include Ohio ant. Indiana. Eastern Pennsylvania, Maryland, and northern Virginia are included in the Washington (D. C.) district. The Atlanta district includes Georgia, South Carolina; Mississippee, and northern Florida.]

Jan 1, 1938

By Ronald E. Hamilton

"An attempt to review the recent literature on comminution reveals at once that the subject has many ramifications and that the applications are so diverse that there are very few general statements which can be made.It. seems reasonable to start classification on the basis of size of material as Input to the comminution process. However, we find that this can only be done in a very imprecise manner.The initial step of breaking rock from its natural state of very large pieces in geological formations into sizes suitable for processing is accomplished by blasting. This step in the process has not been ex-amined in this project except to note that great changes have been made during the last decade or so in the explosives used, and in the method of handling them. We should determine what effect changes in mining methods can have on the need for crushing.The second step in the process is usually primary crushing, performed by gyratory or jaw crushers. The largest chunk which can be fed to a jaw crusher depends on the size of the machine, and should be larger than the largest fragment produced in the miring process. It is obvious that the larger the crusher, the less care required in mining to en¬sure the absence of rocks too large to be crushed. The optimum size of crusher to minimize overall cost of mining and reduction is not at all obvious, and no information on this point has come to light in this investigation.It is rather generally accepted that size reduction is most efficiently done in small stages, and that different machines have different opti¬mum size ranges of feed. For example, crushers are preferred for sizes above about 1"", rod mills for the range between 1"" and 0.1"", ball mills are preferred from 0.1""down to perhaps 10 microns, and vibratory mills, or jet mills, below 10 microns."

Jan 1, 1976

By G. F. Jenkins, P. S. Hobden

Toronto as a geographical area provides an exceptionally wide variety of subsoil stratiphication. Tunneling consequently required a very wide range of adaptabilities to meet its changing conditions. This discussion will provide a summary of work performed in both earth and rock formation using three of our recent works to describe a Contractor's experience. The general subsoil stratigraphy is known to consist of deposits laid down during the Illionian Glaciation followed by the Samgamon Interglacial Stage and finally the Wisconsin Glaciation. All these deposits are underlain by shale bedrock of the Dundas formation. As a whole the Dundas formation is predominantly a greyish blue, thinly bedded shale. The engineering characteristics of the shale vary considerably, however, between a blue clay (argillaceous) shale and a much lighter (in colour) silty and sometimes sandy (arenaceous) shale, and occasional limestone layers. The Illionian deposits are usually found to be layers of pebbly clay till and an overlaying layer of contorted varved-clay. These glacial deposits can be overlain by a thick layer of sandy silt to silty sand which is identified as the Samgamon Interglacial sediments. Because of the action of erosion the Wisconsin till sheets, many times separated by interstadial sands, can vary greatly in their number of layers from zero to three or more.

Jan 1, 1997

By M. Karmis, S. K. Weisiger

The traditional method for training personnel in the mining and other heavy industries has been face-to-face, either via a lecturer in a classroom or through an apprenticeship. With the advent of applications tools such as video, computers, and the Internet, however, a much broader range of training delivery methods is available. Especially exciting are the broad capabilities of multimedia packages that combine the best features of numerous delivery methods. Applying multimedia environments in training holds great potential, especially when there is considerable difficulty in reconstructing real training environments. The authors discuss various delivery methods currently used in training employees, including perceived advantages and disadvantages of those methods. The authors then discuss and evaluate current computer-based training efforts of the mining industry and present an example of a multimedia training tool.

Jan 1, 2001

By Steve Kral

"Liebherr, as most anyone involved with the global mining industry knows, is one of the world’s largest makers of mining and construction heavy equipment. The familyowned company has been around since the 1940s and, according to Stefan Heissler, by the end of next year, will employ about 44,500 people worldwide. Heissler is a member of the board of directors of Liebherr International AG.It all started for the Switzerland-based company when Hans Liebherr first recognized a need for heavy equipment in the construction industry, Heissler said. His first product, introduced in 1949, was the TK10, a mobile crane that, at the time, was a groundbreaking innovation to the heavy construction industry. From there, the company began its growth into a world-leading heavy equipment manufacturer that always relied on innovation.In October, Liebherr gathered a group of mining and construction magazine editors in Leoben, Austria to take a look at the company’s latest addition to the global mining and construction markets. On the mining side, Liebherr provided a demonstration of its T-236 100-t (110-st) haul truck and the PR- 766 50-st (55-st) crawler tractor. The one-day demonstration took place at the Erzberg iron mine near Leoben, where both machines are being proven.The Erzberg Mine, operated by VA Ersberg, has been in operation for about 1,300 years and is said to be Europe’s largest surface mine. It employs about 230 people and mines about 12 Mt/a (13,200 million stpy) of ore, producing about 3 Mt/a (3.3 million stpy) of fine-grained iron ore.T-236 rigid-frame truckThe new T-236 rigid-frame dump truck, with a diesel electric drive system, is Liebherr’s entry into the 100-t (110-st) class and is the first in this class with a four-corner, oilimmersed braking system. The haul truck was first introduced during the 2016 MinExpo in Las Vegas, NV. The unit has since successfully completed its testing phase and is currently in its first field operation trials at the Erzberg iron mine in Austria."

Jan 12, 2017

By Brandon Fryman, Josh Hoffman, Rhys Baker

A post-detonation debris collection project was led in conjunction with a large ammonium nitrate(AN) railcar detonation conducted by the Department of Homeland Security-Transportation Security Administration, Department of Defense-Combating Terrorism Technical Support Office, Sandia National Laboratories, and the U.S. Army Dugway Proving Grounds. This important work will aid in underpinning algorithms used in a Quantitative Risk Assessment (QRA) tool. The test also provided valuable data about the effects and consequences following an AN detonation. The test took place at the Utah Dugway Proving Grounds on April 27, 2018 and the debris collection was conducted the following two weeks with an average of 20 persons per day and an approximate total of 1,400 manhours. A paper was presented at the 2019 ISEE Conference on the collection efforts, challenges, and lessons learned. A complete data analysis effort was completed on the test data in 2019 that resulted in updates to the QRA Railcar Potential Explosion Site (PES)model and AN engine. The analysis included an assessment of the debris data resulting from the Derailed test. This paper is meant to serve as a summary of the analysis effort and findings and as an update to the previously presented lessons learned from the debris collection and analysis effort.

By Paul E. Rosten

This paper describes some of the latest improvements that have been incorporated or planned by the Cleveland-Cliffs Iron Company to reduce operating costs and improve pellet quality. The Cleveland-Cliffs Iron Company operates and manages mining, beneficiation, and pelletizing operations in Michigan, Canada, and Western Australia. This paper deals with the grate-kiln pelletizing operations at Republic, Humboldt, Tilden, Empire, and Pioneer in Michigan, and the Adams and Sherman in Ontario, Canada. Table I characterizes .each operation in regard to location, ore type, pellet capacity and date that pellets were first produced. All of the operations with the exception of Pioneer and Tilden, utilize downdraft-two-pass grate cycles of drying followed by preheating. Pioneer utilizes an all-downdraft, three-pass grate cycle which consists of three drying zones followed by the preheat zone. The Pioneer and Tilden cycles have been described previously. (1) (2)(3) Tilden utilizes a three-pass grate cycle with a stage of updraft drying, followed by two downdraft drying stages. Recuperation systems which supply hot gases to a drying zone from second stage cooling were designed and furnished for Tilden I. Tilden II will be identical. Empire IV will also be furnished with a recuperation system. The Adams grate-kiln system was retrofitted with a recuperation system. This paper will summarize some of the efforts that are in effect or planned for grate-kiln pelletizing systems to (1) reduce operating and maintenance costs, (2) reduce energy requirements, (3) improve product quality, and (4) meet environmental standards.

Jan 1, 1977

By Stephan Großwig, Karolina Nycz, Arne Kindler

"Commonly used anchor monitoring systems are mainly based on the use of anchor force meters. However, experience shows that the reliability of the display of force meters lowers over time. Other measurement and test methods like for example fibre bragg grating method require a comparison with an unloaded optical fibre and give only selective information about the bearing behavior. Moreover the obtained information has to be interpreted. In the following article, first measuring results of an anchor monitoring system based on measurements with optical fibre are presented. The new monitoring system is based on the Rayleigh technology and was used to test the load bearing behavior of the anchor grout body as well as for the evaluation of the grout body condition in concrete-damaging groundwater.INTRODUCTIONThe first fibre optic sensors came onto the market about three decades ago. Initially used as special solutions only in selected cases, now they have found use in almost all areas of technology, especially in areas, where electrical sensor systems reach their limits. The first application examples of spatially resolved fibre-optic sensors in the field of geotechnics have been in existence since the mid-1990s, in projects such as the assessment of the of radioactive repository location sites (Hurtig et al. 1994), for the monitoring of landfill sealing systems (Hurtig et al. 1995) or within the framework of the rehabilitation of mountain farming landscapes (Schreck et al. 1998).The company's first own works in the field of glass fibre measurement technology have been in existence since 1993. The first carried out projects were a monitoring at the Edertalsperre (Dietz et al. 2001), a monitoring with glass fibre tendon at a flood bridge in Carinthia as well as monitoring within the framework of the Storebælt crossing. In all cases, the structure was permanently monitored by means of individual-point measurements. Since 1993 various fibre-optic sensor solutions for geotechnical applications have been introduced to the market (Voet, Glötzl 1996, Hurtig et al. 1994)."

Jan 1, 2017

By Frank C. Stevens

Many changes have taken place in the "World Cement Market" since Joseph Aspdin discovered portland cement in the early 1800's. At the turn of the century, production of cement world wide was a few million tons; today, it is over one billion tons. By 1995, world production is estimated to reach 1.2 billion tons. Cement processing has changed from inefficient, small vertical kilns to large efficient, precalcining kilns, and large automated crushing, blending and grinding systems. Consequently the cost of production has declined in real terms, resulting in significant economic benefits to the general public. In addition, quality and uniformity of cement have increased, strengths have increased, and at least 25% fewer pounds of cement are needed for each cubic yard of concrete. Today, cement moves thousands of miles on the inland rivers and great lakes of the U. S., across Siberia and across the oceans of the world. The volume of cement moving more than a few hundred miles is almost 100 million tons, or 10% of world production. Today, on a per ton basis, it costs no more to move 40,000 tons of cement to the United States from the Western Pacific rim or from Europe than it does to truck cement 200 miles. For example, cement shipped by water from Spain costs $5.00 to $7.00 per ton compared to cement shipped by truck 200 miles at $16.00 per ton. This low cost water transportation has been a major factor for the increased movement of cement between countries. Table 1, Cement Production Summary-World, gives a global picture of production, export and import tonnages in recent years. Figure 1 is a graph showing CEMENT PRODUCTION SUMMARY WORLD WIDE.

Jan 1, 1987

By Paul R. Smith

The Colorado School of Mines Research Institute (CSMRI) was founded in 1949 to fill mining industry and government needs for minerals research and development. The operations of scores of mines, mills, and plants around the world are based on the results of work done by the Research Institute. Among other things, the Research Institute conducts studies in geology, mine planning, mineralogy, size reduction, minerals processing, and hydrometallurgical techniques in extractive metallurgy. Many CSMRI projects also involve energy and environmental considerations. What follows is a summary of some of the studies in which the Research Institute has been and is currently involved, as well as some comments on trends and developments in the industry.

Jan 2, 1982

By P. S. B. STEWART

As part of a continuing study of mechanisms of breakage, the grinding at Nairne Pyrites Pty. Ltd. was traced by the addition of barytes and the results compared with parallel small scale laboratory tests. It was confirmed that the same basic mathematical functions described the behaviour of the full scale ball mill as those established in the small scale mill. However, an additional classification function was required to define the behaviour for the rod mill and was evaluated as a function of size from the experimental data. The classification and grinding of the pyrites ore was assessed from steady state size distributions around the circuit.

Jan 1, 1971