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By Andrew F. McKown, Lewis L. Oriard

Advances in explosives engineering are moving forward in several different aspects. These include improvements and new development in explosives products, the application of these products to blasting technologies, and the study of the peripheral effects of the use of explosives, such as ground vibrations and airblast. Topics of special interest in the last several years include new explosives and detonators, cap timing, explosive casting, high-speed photography, perimeter and slope control, air decking and mathematical modeling of blasting processes.

Jan 1, 1988

By M. Shahsavar, J. Sattarvand, J. Gomez

Mining can be categorized as a hazardous activity, considering some factors such as environmental conditions with a considerable presence of humidity, suspended particles, or falling rocks have affected the severity and number of accidents compared with other economic sectors. The industry analyzes incident reports to narrow the rate of severe injuries and fatalities, conducting root cause analysis and identifying leading indicators. As the International Council on Mining and Metals noted, the vast trove of incident data is not analyzed as much as possible due to a lack of analytics expertise at mine sites. However, machine learning could solve the problem of analyzing all the incident data in a no-timeconsuming way, considering the abundant data, and without using expert personnel in data science. Thus, a Convolutional Neural Network and a Naïve Bayes model were introduced to perform classification in the MSHA database. The database from 2020 consists of 60 fields to describe safety incidents; these fields include mine I.D., accident date, subunit (mill, surface), material extracted, and other metadata.

Jun 25, 2023

By Lindsey Schneider, Steve Kirk, Michael Miglioretti, Jeffrey P. Kolzow, Kyle White

The US17 Spring/Fishburne Drainage Improvements Project utilizes a stormwater conveyance tunnel system of approximately 8,250 LF. The tunnel system includes two intersecting tunnels of differing diameter at a 40-degree angle. The intersection was constructed in soft-ground conditions. This paper discusses the design, geotechnical concerns, initial ground support, and final lining construction. The tunnels utilized two soft-ground TBMs excavated at 15 ft and 11 ft with ribs & lagging initial support. The final lining consisted of unreinforced and reinforced cast-in-place concrete with polymer fibers. Concrete final lining was successfully completed in March 2020.

Jun 13, 2021

By Glenn A. Squibb

An example of market development is described. The market in rail-lake movement of coal is vital to a rail carrier because of its location. This market is threatened by nuclear and other competing fuel sources and by depressed all-rail unit train rates, The first step to develop the rail-lake transportation market consists of rate adjustments and tariff changes to force tighter scheduling of mines, railroad, port and boats, and thus reduce cost. The second step provides a surge pile at the port to eliminate most of the seasonal disadvantage of rail-lake movement and reduce car detention at the port to almost zero.

Jan 1, 1966

By C. G. Cunningham

The Marysvale volcanic field of west-central Utah contains large areas of argillically altered rocks (fig. 1) that, in turn, enclose smaller areas of fine-grained, medium-grade, replacement alunite deposits and coarsely crystalline, high-grade vein-type alunite deposits. The largest replacement alunite deposits are [ ] located peripheral to a 23-m.y.-old monzonite stock called the Central Intrusive (fig. 1). The deposits formed in near-surface, highly oxidizing environments at the tops of hydrothermal plumes that were spaced irregularly around the stock. The deposits are horizontally zoned from alunitic cores through kaolinitic to propylitic envelopes. Vertically, characteristic alteration minerals progress from a pyrite-propylitic alteration assemblage at the base, upward through alunitic, jarositic, and hematitic assemblages to a flooded silica cap as shown on figure 2. The silica caps are cut by hydrothermal explosion breccias. d34Sso4 values of + 11.5 to + 15.4 permil indicate that sulfur in the hydrothermal plume was derived from underlying Mesozoic evaporites. The sharp upward transition from pyrite- propylite to alunite probably marks the paleowater table, and the top of the flooded silica cap represents the paleoground surface. Basin-Range extensional tectonism began shortly after alteration, and buried the replacement alunite deposits in basins beneath sediments eroded from uplands. The deposits were only recently exhumed.

Jan 1, 2013

By C. A. Garcia

The solvent extraction of gold cyanide from alkaline cyanide solutions with monosubstituted guanidines, bis disubstituted guanidines and a tetrasubstituted guanidine was investigated. The guanidine functional group is protonated in alkaline solution and the guanidinium cation is stabilized so that the aurocyanide anion can be extracted even at -pH 12 if an appropriate carrier is used. Typical aprotic carriers including both aliphatic and aromatic solvents limit gold extraction by guanidines to pH 10; whereas the presence of an alcohol extends gold extraction to pH 12. UV spectroscopy suggests that the alcohol facilitates protonation of the guanidines, stabilizes the guanidinium cation, and facilitates gold extraction at high pH.

Jan 1, 1993

By William N. Poundstone

Since World War II, when off-track mining became popular, mining machinery has undergone much change. However, the change has been basically to make the machines more powerful, more productive and more reliable. Little change has been made, in this period, in the basic mining system. While steady improvement was made in productivity until the passage of the new Federal Coal Mine Health & Safety Act, I believe that the cost Co benefit ratio of further improvement from this basic approach of improving the existing extractive tool is not as promising as I believe may be obtained from a new approach. Consequently, six years ago Conoco and Consol undertook a comprehensive long-range R&D program to see if improvements of a more basic nature could be made in underground mining. We concluded early in our program that while many things currently limit the rate of production such as the rate at which roof can be supported, time needed to advance ventilation systems, time required to clean up and rock dust, time required to maintain and service equipment as well as time lost due to haulage deficiencies, that the key to improvement was a truly flexible continuous high capacity haulage. With face equipment in use today, mining rates can be increased with such a haulage system where the ability to support the roof exceeds the ability of conventional haulage equipment to remove the coal. More importantly, if we could develop such a system, it would set the stage for development of far more sophisticated methods of mining at the face than exist today, and as new and more dependable mining machines and methods are developed, continuous transportation will enable the gains envisaged in production to be realized.

Jan 1, 1974

By L. J. Tucker

The magnetite orebody at Pea Ridge strikes NE-SH and dips at about 800 to the SE. The ore is high grade magnetite with a strike length of over 600-m and a maximum width of over 180-m on some of the levels. The shape and the mineral content of the iron orebody have been fairly consistent so far. The iron ore and surrounding basement rocks are Precambrian in age. These rocks are usually very competent, about 400-m of sediments lie over the ore.

Jan 1, 1991

By M. Javier

"Mining makes civilization possible. It also creates socio-economic problems surrounded by sustainability controversies yet continues extraction without considering the balance and finitude of nature. Nature requires restoration of equilibrium if mining and life on earth are to continue. Mining is still practiced according to Agricola’s views and the consequences it has wrought on our planet demand we critically reexamine it from its very core, to its metrics, to its design, to its technology, to how it is taught, and to reconsider its raison d'être in 2017. This paper offers tools to new mining engineers that are required to transform and solve new challenges. The task before us is to formulate an updated core curriculum that meets the demands and realities of the 21st Century. Mining professionals must rethink and reteach how to redesign mines before shovel hits dirt, how to mine with restoration of nature figured in to the mining design. Mining needs a new extractive technology in order to transform the results of its well-known liabilities. Mining has evolved and its future must be different than its past. Our industry is capable of doing this but it needs to be shown the way. INTRODUCTION The statement that ‘mining makes civilization possible’ is of the utmost importance and has the most value to us. We can examine the past and present appropriately to see the future that we are building. Mining must be addressed in a different way that makes a positive difference and improves upon rather than continues to get the negative impacts of the past. See Fig 1. Mining creates disequilibrium in Nature by producing ore, waste, tailing, dilution of resources, toxic, and pollution to its ecosystems. What is next for mining on a limited planet? Delaying the transformation of mining is not an option to developing an updated and modern mining business-as-usual paradigm. It is hurting the essentials of living in a civilization; our livelihood is in danger to the point of unrest in nature as we generate a lot of eco-print by present mining practices. So, we are urged to eliminate this bottleneck in life by employing a different design. This way, we will have a vision on how to sustain our civilization. [1]. This new design, with input from current and future generations, will be our contribution to posterity."

Jan 1, 2018

By J. F. McDonald

On December 8th of last year, the new St. Clair River tunnel was holed-through to Port Huron, Michigan. The tunnel, commissioned by the Canadian National Railway, was needed to replace an existing tunnel that had been built between 1889 and 1890, and had remained in continuous operation until the new tunnel was opened to traffic in April of this year. The original tunnel, after more than 100 years of service, was still structurally sound, but was too small to accommodate the double stacked container cars and other advances in the railroad's equipment that had developed over the years. Prior to the construction of the first tunnel, all freight was barged across the river. It was a slow, expensive process, which in winter was sometimes impossible. The nineteenth century tunnel was built in twenty months, utilizing two shields that mined to the middle from each end. The lining, which is still in excellent condition, consisted of bolted, cast iron segments, with an O.D. of 6.4 meters. It was the first sub-aqueous tunnel built in North American, and it's use of compressed air under the river and hydraulic power on the shields may also have been firsts. The digging was done by hand, and the muck hauled out by mule drawn wagons. Boulders and methane gas were reported to be a constant problem during the drive, and compressed air sickness was common, but when the two shields came together in August of 1890, it was reported that the alignment was within 6 mm. The new St. Clair River Tunnel was constructed for basically the same reason as the original. The larger equipment which the railroad is using today would not fit through the old tunnel, and once more they were forced to ferry the cars across the river.

Jan 1, 1995

By Bahaa Alyosif, Turan Uysal, Muhammet Kürsat Aydemir, MURAT ERDEMOGLU

 The paper investigates the effect of intensive milling on the conversion of microcline to potassium chloride during chlorination roasting. The study aims to improve potassium recovery by reducing the chlorination roasting temperature through mechanical activation.

Aug 1, 2023

By R. T. Swinderman

"Virtually every article you read on safety has a statement to the effect: “It’s obvious that safety pays”. If it is so obvious, why is it so hard to answer these questions? • How does the Maintenance or Operations Manager convince the Plant Manager to spend money from the annual budget for safety improvements? • How does the Plant Manager influence Corporate to prioritize safety improvements? • How does an engineering firm persuade the owner to spend more on design and equipment up front to reduce risk? There are many cultural and structural reasons why it is so difficult to prove the obvious. In my opinion the main culprits are: the almost universally used ‘Low Bid’ process, variations in reporting incident statistics between industries and countries, and, the Generally Accepted Accounting procedures (GAAP) [or International Financial Reporting Standards (IFRS)]. Conventional wisdom is it’s smart not to spend more than you need to meet the minimum regulations and maximize production. But buying on price alone often harms people, degrades the environment, and reduces the company’s bottom line. How can this be? You met the minimum safety requirements and saved money by buying on price. Don’t those savings go right to the bottom line? When you buy on price you get minimum quality, minimum compliance and are often backed corner with no reasonable options to rectify the problems that arise from buying on price instead of buying on long term life cycle cost. Culturally few companies actually ‘walk the talk’. It is trendy to have giant billboards at plant entrances proclaiming world class compliance with quality and safety standards. Annual reports are embellished with safety slogans and sustainability statements. Behind the front gates and the glossy annual reports the message is clear: produce or be replaced. Only a few companies go beyond the window dressing and actually endorse, from the top down, continuously improving their safety culture. Those that do embrace safety, show significant performance advantages over their competition that are reflected in their safety, productivity and environmental records and, ultimately their financial statements and share price. Current accounting (and reward) systems make it unlikely financial managers will accept non-conventional approaches to justifying expenditures on safety because they are driven to report “hard” numbers that can be documented and are within the “GAAP or IFRS Rules.” But in reality, accountants quantify soft or intangible costs all the time in their financial statements. Justifying safety investments is greatly enhanced by quantifying what most financial managers would call intangible costs. Government agencies have no problem assigning intangible costs to justify regulations to improve safety. How many times have you heard that the regulation is justified because the cost to industry is X while the benefit to the society is 2 or 3X? How can they say that without including intangible costs? We find it hard to believe these government claims of benefits to society because we have been trained to think about saving hard direct costs to justify investments."

Jan 1, 2017

By Diana Diaz, Rakshith Shetty, Vitaly Proschenko, Mike Mooney

Cohesive clay soil poses a significant risk to earth pressure balance tunnel boring machines (EPBM) due to unstable face pressure, clogging potential, high cutterhead torque, poor muck flow, low advance rate, etc. This paper details the performance measures desired when EPBM tunneling in clay soil, and the scientifically-supported conditioning methods to transform in-situ clay to a muck with such characteristics, giving particular attention to ground conditions. The paper then examines TBM data from multiple clay soil projects in the context of these performance measures to demonstrate the influence of cohesive soil conditioning on EPBM performance.

Jun 13, 2023

By W. R. Ernst

A method for the removal of nickel and vanadium contaminants from spent HDS catalysts involves pretreating the catalyst with H2S followed by the extraction of the metals with an acidic solution of ferric ion. The ferric ion solution alone removes significant amounts of active ingredients cobalt and molybdenum; however, after pretreating the catalyst with H2S, the extraction becomes more selective for the removal of Ni and V.

Jan 1, 1986

By T. J. Fenner

Research conducted in South African mines has demonstrated the benefit of ground penetrating radar for the detection of geologic features and hazards. This is crucial for safety and production considerations in underground mines that are as much as 4 kilometers deep. This paper describes a new ground penetrating radar system designed specifically for high quality data acquisition, in the harsh conditions of deep underground environments, for use by operators with minimal geophysical experience. Design criteria included automated functions, intrinsic safety, light weight and minimal power requirements. Data is processed on the ground surface by geoscientists using a PC.

Jan 1, 1994

By James P. Connell

HISTORICAL BACKGROUND The American Concrete Institute defines shotcrete as "mortar or concrete conveyed through a hose and pneumatically projected at high velocity onto a surface." This definition thus includes what is traditionally known as gunite, which is a pneumatically applied mortar. In mining practice, the term shotcrete is restricted to pneumatically applied concrete, and this differentiation will be used in this chapter. In 1914, following the invention of the mortar gun in 1907, then chief engineer of the US Bureau of Mines (USBM) George Rice developed the gunite process for underground test work at the USBM facility at Bruceton, PA. After World War I, gunite was used extensively in American mines and was also utilized for underground civil works such as the San Jacinto tunnel in California. The greatest development was in Europe where, as early as 1911, gunite was successfully used as an overlay for deteriorated tunnel linings. In 1951, the Swiss firm Aliva developed a pneumatic gun capable of handling coarse aggregate, thus making possible the first use of shotcrete at the Maggia hydropower development. Initially, shotcrete was used to reduce manpower requirements for forming and placing conventional concrete. However, by 1954 Sonderegger was reporting that the structural advantages of shotcrete were derived from its flexibility and from the fact that it could be applied almost immediately after the opening had been made. The incorporation of wire mesh into the shotcrete led to the new Austrian tunnel method or NATM. The use of shotcrete in American mines has been implemented more recently. This delay seems to be due to previously unsuccessful experiences with gunite as a structural material and to the US reliance on wood or steel supports in main-line haulageways. The long experience with the apparently more substantial rigid supports led mine operators to be reluctant to accept the new and seemingly unrealistic lighter shotcrete support. APPLICATION REQUIREMENTS Shotcrete is a relatively new material for use in underground support systems. Consequently, experienced miners are not always available who are capable of applying the material effectively. Shotcrete, particularly in the small cross sections typical of mine shafts or haulageways, is applied in cramped quarters under less than ideal conditions. Adequate lighting should be made available. The surface should be clean and free of running or dripping water. It may be necessary to collect flowing water in plastic pipes or water collection devices. Any dry cement dust from previous shotcrete applications should be washed from the surface in order to assure a good bond. The US Bureau of Reclamation (USBR) while shooting test panels at the Cunningham tunnel in 1974, found that experienced shotcrete operators were able to obtain up to three times greater compressive strengths than were obtained by unskilled operators using the same equipment and shotcrete mix. ENVIRONMENTAL AND SAFETY REQUIREMENTS Since sodium and potassium hydroxide, as well as other moderately toxic compounds, are often contained in shotcrete (particularly where accelerators are used), safety precautions must be taken to prevent skin and respiratory irritation. Nozzlemen and helpers are required to wear gloves, protective clothing, and ventilation hoods with a filtered air supply. Respirators approved by USBM, equipped with chemical filters that will not pass the caustic mists, may be permitted in lieu of hoods if goggles or safety glasses are worn. Protective ointments are available to reduce skin irritation. All air and shotcrete feed hoses should be equipped with safety-type couplings and secured with safety chains at each coupling to prevent whipping in the event of a hose or coupling failure. Some environmental effects can take place down-stream from the development face being supported. The accelerator compounds, as well as the portland cement used in the shotcrete, will be found in the rebound material which falls to the invert of the heading. Since these compounds may be leached from the rebound material and carried by the drainage system, it may be necessary to install neutralizing or other water treatment facilities. Investigations may find that the final reaction with other compounds being leached from the mining operations may result in a more or less environmentally acceptable end product. USES OF SHOTCRETE General Uses Shotcrete, as a combination of cement, aggregate, and accelerator, is utilized for underground openings such as shafts, adits, haulageways, and service chambers for the following general purposes : (1) primary sup¬port; (2) final lining; (3) protective covering for excavated surfaces that are altered when exposed to air (the protective covering may be of a temporary or final nature); (4) protective covering for steel or wooden supports, rockbolts and rockbolt plates, heads, nuts, and other mats, including wire fabric, used to prevent rock-falls; and (5) as a lagging material in place of timber, steel, or concrete between steel or wooden supports. These applications can be grouped into three general use categories: shotcrete used as a rock sealant, shotcrete used as a safety measure, and shotcrete used as a structural support. Use as a Rock Sealant Thin applications of shotcrete can reduce or prevent slaking of shales or other rocks that are altered when exposed to the wetting and drying cycles created by mine ventilation circuits. While shotcrete may be effective in preventing such rock alteration, at the present time it is not as economical or efficient as other commercial sealants. However, if the sealant property can be incorporated into the structural support capability, the added contribution is usually helpful. Thin applications are not usually sufficient if the alteration of the

Jan 1, 1982

By Henry J. Jacoby

This report concerns Contract No. 3B of the Port Richmond Project, for the Department of Water Resources of the City of New York. It involves the construction of 7, 000 ft. of 7 ft. finish I. D. interceptor sewer by tunneling in soft ground, as well as associated manholes, regulator chambers, siphons and miscellaneous sewers and structures, beneath a heavily travelled perimeter road in Staten Island. The Contractor is Richmond Constructors, a joint venture of Grow Tunneling Corp., sponsor, MacLean Grove & Company, Incorporated, Morrison-Knudsen Company, Inc., and Andrew Catapano Co., Inc. Project manager is Paul DeMarco, Vice-President of Grow Tunneling Corp. The cortract, as designed and bid, requires the use of liner plates 101 -0" O. D., and both cast iron and steel designs of several widths were included in the bid documents by the owner. The specifications also required the contractor to install and put into operating condition, prior to commencement of mining, a complete low pressure compressed air plant and all accessories for mining in compressed air, even though the contractor was given the option of using other methods of ground water control. A third requirement of the specifications was that a shield be used, either manual or mechanical, and with full provision for "breasting". BACKGROUND The first soft ground shield driven tunnel in the United States was in New York City and was built under Broadway in lower Manhattan in 1869

Jan 1, 1974

By George McArthur

GEOLOGY One of the largest copper resources in North America occurs in the Bingham mining district, located 40 km (25 miles) southwest of Salt Lake City, UT. Anaconda's present contribution to the development of this resource is the Carr Fork mine. (Fig. 1, Bingham district plan map.) The Carr Fork story began about 300 million years ago when a thick sequence of sedimentary quartzite and limestone was deposited in the Oquirrh Basin. Subsequent earth stresses formed a series of west-northwest-trending overturned anticlines and synclines that were later offset by northwest-striking thrust faults and northeast-trending normal faults. (Fig. 2, Bingham district cross section.) About 38 million years ago the Bingham stock was intruded into some of the folds, resulting in the formation of porphyry ore in the intrusive, and fissure, replacement, and skarn ore deposits in the sediments. The Carr Fork skarns were formed preferentially in two limestone units, called the Yampa and Highland Boy, which average about 46 m (150 ft) in thickness, separated by about 76 m (250 ft) of quartzite. Copper mineralization consists almost entirely of chalcopyrite associated with pyrite and molybdenite in a gangue of garnet, diopside, magnetite, quartz, and carbonate. Molybdenum, gold, and silver are economic byproducts. (Figs. 3 and 4, indicated ore in plan and section.) EXPLORATION HISTORY The West Mountain mining district, of which Carr Fork is a part, was organized in 1863, after leaf-silver ore was discovered in the Carr Fork of Bingham Canyon. However, it was not until 1873, when the Bingham and Camp Floyd railroad to the town of Bingham was completed, that the mining camp flourished. Many small mining companies in the district were reduced, often through consolidation. By 1937 only the National Tunnel and Mines Co. was active in the Carr Fork area. In 1948 it declared bankruptcy, and was later purchased by The Anaconda Co. Anaconda conducted geologic investigations in the Bingham district until 1968, when a concerted diamond drilling program was initiated to fully evaluate the geologic potential of the Carr Fork area. The exploration program commenced with one diamond drill, but was enlarged to three drills following discovery of the first major ore intercept. Near completion of the exploration effort, large oil well rotary drills were used to drill to depths of 762 to 914 m (2500 to 3000 ft), after which the holes were completed by standard diamond drilling techniques. All holes were collared vertically, but considerable deviation occurred because of structure and rock conditions. Wedging and directional drilling were used to keep the holes on target and to provide multiple ore intercepts in the deeper holes. Geophysical surveys, in-

Jan 1, 1982

By C. W. Lockhart

Strength evaluation programs, based on sub- jecting a number of 5-718 inch (0.15 m) diameter core samples from highly fractured or poorly consolidated rock, to triaxial compression tests, have been successfully completed. An innovative approach was required since con- ventional methods with similar materials had not produced reliable results. Drilling methods were modified, and specially designed transparent core barrels were used. Sample preparation was successfully accomplished by using speciallydesignedtools and unorthodox hand- ling methods. Initial tests were carried out on weathered oxides from an open pit copper mine. The technique was later used successfully where the test material was weak, friable coal. The procedures used offer a practical method of testing weak materials where conventional methods would not be successful.

Jan 1, 1980

By Michael Michaylov, Elana Vlasseva

This paper presents a method for three-phase foam preparation recipe optimization. The pressurized foam is injected into porous media of gob area for prevention and fighting of SPONCOM fires. The method includes laboratory experiments for main foam properties as well as mathematical optimization procedure. Optimization criteria are formulated reflecting foam application purposes. The influence of solid phase on foam heat stability is shown. Results from optimization procedure for four foam agents by varying fly ash consistency of foam are presented. Theoretical basis for original construction of foam generator, specially constructed for of three-phase foam generation, is set u

Jan 1, 1997