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Jan 1, 1999

By Steve Karl

"The global underground construction and tunneling industry is in pretty good shape. Billions are being spent in shoring up aging infrastructure in the United States and other places, and new underground projects are being put out for bid.With each new project, comes new equipment, technology and tunneling methods. So it is incumbent on tunneling professionals to constantly improve their knowledge of the profession. This is where spending a few days with other underground construction professionals can assist the tunneler in keeping up.Every two years, tunnelers and underground construction engineers, contractors, suppliers, designers and owners from around the world gather for the Rapid Excavation Tunneling Congress (RETC). The 2017 conference was held in June in San Diego, CA. The UCA of SME puts on the conference.This years’ RETC attracted 1,400 attendees. The accompanying sold-out exhibit totaled 188 service and equipment suppliers. In addition, the conference had the UCA of SME bookstore, where the new History of Tunneling in the United States book was introduced. And a short course on tunnel rehabilitation was featured.Technical programmingRETC 2017 featured nearly 100 technical presentations. Topics covered the breadth of the global underground construction industry. Here is a sampling of a few. The proceedings from the conference is available from SME, 303-948-4200, www.smenet.org.Accomplishing extraordinary tasks as a machine supplier for Metro Doha: The construction of the Metro Doha in the State of Qatar established a modern, safe, efficient and integrated public transportation network. Upon final completion of multiple phases, the network will comprise four metro lines with a length of 216 km (83 miles) and 100 stations. Phase one comprises 112 km (43 miles of underground tunnels (56 km or 22 miles of twin-tube tunnels). Twenty-one earth pressure balance tunnel boring machines (TBM) were deployed by the four different joint ventures. The project was initiated, managed and supervised by the owner, Transport Authority Qatar Rail.Phase two of the Doha Metro will start upon the completion of Phase One in 2019 (Qatar Vision 2030). The owner placed full faith in the manufacturer’s abilities to deliver equipment of high quality, state of the art standards within the given time frame. This paper focused on the manufacturer’s scope of delivery and on the supplier’s high standards of quality in production, logistics and services."

Jan 9, 2017

By Joseph Keenan

In March of 1994, Dynatec Mining Limited entered into a contract with PCL Civil Constructors to carry out the underground excavations for the Algonquin Power Corporation’s15 Megawatt Nagagami hydro-electric power station located near Hearst, Ontario, Canada. Dynatec completed the work for this project in early October 1995. Dynatec Mining Limited’s work included the excavation of a 175 meter long penstock driven at a grade of -25% to a 4000 m3 powerhouse located 50 meters below the intake elevation. A 1200 meter long tailrace was driven from the Nagagami River to connect with the powerhouse. Two 50 meter raises were driven from the powerhouse to surface to pro-vide access for equipment and personnel. The excavation of the tailrace tunnel(5.8m x 5.9m) was completed using Dynatec’s Long Round Jumbo Technology.

Jan 1, 1997

It was shown previously that chalcopyrite could be floated without using a collector when the ore samples were treated with small amounts of sodium sulfide (Na2S). The role of this reducing agent was considered to be one of a cleaning agent to remove the hydrophilic surface oxidation products. It was later found, however, that the collectorless flotation could be obtained only under slightly oxidizing conditions. This might suggest that collectorless flotation is not due to the clean surface but to the elemental sulfur which may be present as an incipient oxidation product. Therefore, a search for the presence of elemental sulfur has been made by means of ESCA, mass spectrometry, and solvent extraction followed by W spectrophotometric analysis. On the basis of these results, the mechanisms of collectorless flotation are discussed.

Jan 1, 1983

By Vaughn E. Livingston

Washington State has a variety of industrial minerals and although not many are produced currently (1982) most have a history of production (table 1). The value of industrial minerals produced in the state exceeds by several times the production value of metallic minerals. In 1981, 15 minerals - cement, limestone, clay, gemstone, pumice, sand and gravel, stone, diatomite, gypsum, olivine, peat, talc, garnet, silica, and dolomite - were produced. Combined value of nonmetallic production for 1981 is estimated at $218,999,000. Cement had the largest estimated value at $102 million, followed by sand and gravel at $47 million, and crushed stone at $29 million. These figures are from the US. Bureau of Mines preliminary production figures for 1981.

Jan 1, 1982

By R. C. Woodhead

During past years the most difficult problem presented to the coal preparation engineer has been the cleaning of fine coal, The problem of handling fine coals is more involved than the coarser sizes, because the higher surface moisture contents complicate screening, and the larger percentages of fine near size material complicate separating problems. Low gravity high capacity specific gravity separations were not possible with equipment available at that time. Coal preparation engineers did develop machines that would effect a separation of the fines, however, to maintain a high efficiency, the point of separation had to be a relatively easy one. The more difficult separations were made in the coarse coal sections of the washeries, and the fines were generally cleaned at higher specific gravities in equipment such as tables, feldspar jigs, rheolaveurs, etc. Clean products from both processes were mixed, resulting in overall lower ash contents, During the last several years, however, we have been confronted with increasing demands ZGP more precise separations of finer coals to still further reduce ash contents. A study was begun and a program instigated to improve the cleaning of fine coal, The result of this endeavor was the development of the new cycloidal heavy medium cyclone.

Jan 1, 1964

By L. Cui

A new flotation collector, benzyl arsonic acid, was used for the flotation of ilmenite. ESCA, Auger spectroscopy, and chemical analysis were used to investigate the correlation between the variation in surface constituents and the flotation recovery of ilmenite. Experiments indicated that, as the ratio of surface Ti ions/surface Fe ions increases, flotation recovery increases. pH regulation with an inorganic acid was found to be effective in changing the ratio of surface ions, and, hence, the flotation recovery.

Jan 1, 1986

By R. L. Grayson

In 1995, Congress abolished the Bureau of Mines in the Department of Interior but preserved the safety and health research functions being performed at the Pittsburgh and Spokane Research Centers. These functions were transitionally housed in the Department of Energy before permanently merging with the National Institute for Occupational Safety and Health (NIOSH), Department of Health and Human Services, in October 1996. Since the merger of the former Bureau with NIOSH, there has been an active evaluation of ongoing research activities, significant interaction with stakeholders, and the development of a process leading to "data informed" priority setting. This presentation will review current surveillance information concerning the level of injury and disease from mining work and will discuss how research priorities are evolving to improve the contribution of research to the prevention of injury and disease.

Jan 1, 1998

By H. W. Newcomen, D. R. Brox

Assessments of the stability performance of open pit highwalls have traditionally been based on consideration of surface movement rates. Although generally accepted in industry, this approach presents challenges for establishing appropriate threshold values to allow for safe mining operations and does not address the issue of total strain. Surface movement monitoring data from a limited number of open pit mining operations in North and South America has been evaluated in terms of highwall strain, rock mass quality and inferred mechanism of instability. Threshold strain levels for key stages of highwall stability proposed from previous work have been reviewed and are generally endorsed based on evaluation of additional data. An empirical highwall strain criteria for the assessment of highwall stability performance is postulated based on the observed trends in highwall strain data from the case histories presented.

Jan 1, 2004

A conventional paddle-type mixer and a gravity flow mixing device were evaluated for conditioning of phosphate ore with fatty acid and fuel oil, and for acid scrubbing prior to cationic flotation. Gravity flow mixing required less residence-time, but slightly higher reagent concentrations to achieve recovery levels similar to conventional conditioning. Grade was less sensitive to reagent concentration using the gravity flow mixer. For acid scrubbing, the gravity flow mixer proved equally effective. In this paper, the effect of time, pulp density, reagent concentration, and emulsification on conditioning and acid scrubbing efficiency of the two devices will be discussed.

Jan 1, 1987

By C. L. Glorioso

As an introduction and credentials for our talk, let me take a moment to introduce you to Wimpey Worldwide and specifically to Wimpey Minerals, USA, Inc.

Jan 1, 1995

By Kunzo Amano

Fully-bonded rock bolts have been widely used in construction sites and mines in recent years. The purpose of this investigation is to prove the effectiveness of rock bolt supports in unstable ground through in-situ tests and numerical analysis. 2. MEASUREMENTS AND PROCEDURES OF IN-SITU TESTS The fully-bonded rock bolts as the mine road¬way supports were tested in the Fukasawa mine which is located in the northeast district of Japan (Fig. 1). The Fukasawa mine (one of the Kuroko mines) started the production in 1973, and the present monthly production is slightly less than 20,000 tons. The ore deposit which exsists at about 400 m depth is divided into several small lenticular shaped bodies. They are distributed apporiximately 1500 m in NW-SE direction and 700 m in NE-SW direction. The hanging wall is basaltic lava and the footwall is tuff. The rocks surrounding the ore bodies are soft but relatively intact, so the trackless mining system has been adopted from the beginning of the development.

Jan 1, 1982

Crushing and grinding The Crushing and Grinding Technical Committee There was substantial activity in the area of crushing and grinding with the improved outlook in the industry. The Crushing and Grinding Committee's theme of 1987's Annual Meeting in Denver was Fundamentals of Mechanical Design for Crushing and Grinding Mills. At the meeting, the concept of gearless sag mill variable speed drives was taken out of the closet, dusted off, and a wraparound motor was put on hard copy with the ordering of a 9.7- x 4.5-m, 8.2-MW (32- x 15-ft, 11,000-) sag mill. Additionally, comparisons were provided to the mill design of the gearless drive sag mill and the twin 4.5 MW (6000 hp) do variable speed drives placed on the drawing board for the Kennecott UCD Expansions. This involved a 10- x 4.5m, 8.9 MW (34- x 15 ft, 12,000 hp) sag mill. Differing opinions were also expressed in technical presentations pertaining to the need for quality mill specifications in design and manufacturing. J. Berney-Ficklin of Bechtel presented a paper outlining the need for quality design and manufacturing specifications in large scale grinding mills, and the overall cost reduction in capital and operating costs. Others presented differing specific views, but all emphasized a central theme. Quality and reliable designs in large mills should not be compromised. In-pit crushing applications continue to increase, overseas and in the US, in both mining and quarrying. Different in-pit crushing units have been classified as mobile, with integral transport systems; semi-mobile, typically modular systems that use separate transporters for repositioning; semi-stationary plants that must be dismantled before transporting and typically require earthwork and concrete foundation work; and stationary in-pit crushing plants, which remain in place for the life of the pit. The majority of equipment sales of conventional crushing and grinding circuits in 1987 were to gold mining operations. There have been two areas of end use: • conventional jaw/gyratory or impact crushing circuits preparing low grade ores for heap leaching; and • small scale sag/ball mill circuits preparing higher grade ores for classical cyanide leach/ recovery circuits. There was also continued interest in ABC and SABC circuits for both base and precious metals plants. High pressure roll crushers continue to attract considerable interest in the cement industry. There, they are used to prepare raw materials or clinker for subsequent ball/tube milling. However, they have apparently been less successful in the mineral industry where the energy savings/ capacity gains have been much less dramatic. Several papers covering the theory and application of these machines were presented in an industrial minerals session on cement at the SME Annual Meeting. The Third International Conference on Hydrocylones, held in England in October produced several papers of interest on classification and screening to the mining industry. In particular, a new cyclone apex, developed by Mt. Newman Mining, shows promise of reducing water flow to the cyclone underflow stream and, therefore, increased underflow pulp densities and reduced fines recycle in grinding circuits. A twin vortex hydrocyclone was also described and shown to give a sharper split than conventional units. Similar double cyclones were introduced in the 1950's, but failed to achieve widespread acceptance. This was due mainly to a proneness to blockage in the transitional zone. It will be interesting to see whether this latest variant can overcome this problem in the typical operation. A number of North American iron ore plants installed the capability to produce fluxed iron ore pellets. Most chose to grind the stone on site with circuits designed to grind taconite ore. Methods employed to grind this material included single-stage ball mills closed with fine screens, rod and ball mill circuits - both open and closed with cyclones - and semiautogenous mills, followed by ball mills closed with screens or cyclones. Dewatering and tailings disposal B.M. Moudgil and D.L. Sober, University of Florida Due to tightened environmental regulations and the need for more efficient land use, a greater interest in dewatering and waste disposal has developed. As a result, research efforts in flocculation, surface chemistry, and polymers science have focused on the problems related to the dewatering of solid mineral wastes. A few studies have been conducted to examine the flocculation process. Hogg et al., (1987) discussed the formation and growth of flocs. They determined the size and density of flocs was controlled by the physical conditions of the system (e.g. agitation,

Jan 5, 1988

By L. A. Wasselle

The Israel Mining Industries Institute for Research and Development has developed, during recent years, a number of new processes for fertilizer materials. Their phosphoric acid processes, however, are capable of producing an acid of far higher quality than that normally associated with fertilizer grade acid. This paper will discuss two of these processes showing the quality attainable and the capital and operating costs for, U. S. conditions. The Standard IMI Process is based on the acidulation of phosphate rock with hydrochloric acid and involves solvent extraction for the separation of high quality, phosphoric acid from the resulting solution. The IMI Purification Process applies the same solvent extraction technique to the purification of a wet process phosphoric acid from sulfuric acidulated rock. IMI has built and operated a semi-works scale demonstration plant for the standard process. The first commercial plant was started up in; Japan in 1962. This small seven metric ton per day plant is currently producing a furnace quality acid. A larger 50 metric ton per day plant is nearing completion in Brazil. Another 50 metric ton per day plant is under design while a large plant with a capacity in excess of 150 metric ton per day is in the planning stage. Both of the latter facilities are for Israel.

Jan 1, 1966

By Josh Swank

Albert Einstein once said, ?the important thing is not to stop questioning.? In the mining industry, a lack of inquisitiveness may lead to a blissful ignorance but it certainly will not increase efficiencies. While one may claim necessity is the mother of invention, questioning and analyzing how methods and systems can be improved is the catalyst to discovering necessities. Understandably, when working in the middle of Canada?s oil sands, where trucks operate around the clock every day of the year, it is nearly impossible to pull the nose from the grindstone long enough to provide thorough analysis. But, fortunately, some manufacturers/inventors have assisted by examining the process and the ensuing headaches within this application.

Jan 1, 2013

By Kevin Saeler, Patrick Willaman

Utilizing automation is one way to improve competitiveness. Roof and rib bolting in underground coal mines has not changed significantly for more than 40 years. Most roof bolting is still a largely manual process involving high levels of staff carrying out repetitive work. Roof bolting statistically has one of the highest levels of underground accidents, including finger, hand, and arm injuries. Operators are exposed to falling objects and becoming entangled in roof bolting apparatus while roughly moving awkward 6-ft drill steels and roof bolts. It is estimated that over 25 million roof bolts are installed annually in the U.S. underground coal market with well over 1,500 operators involved in roof bolting on a day-to-day basis. Recently electrohydraulic roof bolting rigs have been installed to offer partial automation of the drilling cycle and the bolting cycle. The next stage is to provide a storage and loading system to allow full automation of fullcolumn resin roof bolts. This paper reviews the latest electrohydraulic roof bolting equipment and discusses the testing of a fully automated drill rig. Full electronic control allows each step of the roof bolting process to be recorded, providing a digital record of each installation, including hole depth, spin time, gel time, torque, and cycle time. Other benefits include monitoring of water pressure and flow, used to prevent blocked drill steels as well as digital fault finding. A fully automated roof bolting machine greatly improves operator safety and gives high-quality repeatable roof bolting with reduced cycle times.

Jul 1, 2023

By Paul R. Wieber

This paper describes the U. S. Energy Research and Development Administration's (ERDA) program to develop in situ coal conversion processes, especially gasification, he potential of this technology, the technical directions being explored, and the program strategy to carry the process concepts toward commercialization are emphasized. The geographic location of the U. S. coal resources and a market analysis are described. Commercially successful in situ coal processes could add over a trillion tons of coal to the U. S. coal reserves. The economics of these processes is compared with surface gasification independent studies show this process to be 25Z cheaper than surface gasification for Western coals. The major projects are briefly described. The Linked Vertical Well process is in the lost advanced stage and shows great promise. The last test produced a low-Btu gas averaging 171 Btu per standard cubic foot for average pro¬duction rates of 5.5 million standard cubic feet per day. The other projects are Packed Bed, Longwall Generator, and Steeply Dipping Beds.

Jan 1, 1977

By Michael J. Cruickshank

MICHAEL J. CRUICKSHANK SENIOR AUTHOR Marine mining is a very broad field. It encompasses every facet of terrestrial mining but with the unique addition of a superimposed liquid overburden, which is itself mineralized. It is the unique aspects of marine mining that are discussed in this section. In keeping with the times, a systems approach is taken in the presentation of the material. The environment is first described, and this is followed in logical sequence by the common requirements for working there, then the mineral exploration phase, the exploitation and, finally, the operational restraints imposed by man and nature. Free use is made of tables and figures from original and published works and extensive listings of reference material round out each section. The title "Marine Mining" was chosen in preference to ocean or underwater mining because it is broad enough to include oceans, beaches and inland seas. The selection of terms sometimes may seem odd but they have not been chosen arbitrarily. All things are reduced, where possible, to basics and defined. Applying systems terminology, the word "platforms" is used in the functional sense and includes not only airborne, waterborne and fixed platforms, but man himself in his capacity as a working diver. If there is confusion it is often because of familiarity with a word in a context personal to the reader. For example, what does extraction mean to you-or mining or exploitation? Cost data have been interspersed throughout the section whenever they could be obtained. The use of these data should be tempered with understanding because no two situations are alike and improvements in marine technology are constantly being made. The names of individual authors are listed with each subsection. Where no name is given, the responsibility has been that of the senior author. Acknowledgment is sincerely made to the U.S. Bureau of Mines, and latterly the National Oceanic and Atmospheric Administration, for encouraging and supporting the preparation of the work ; to the secretarial staff at the Marine Minerals Technology Center and to Donald Eisman for editing. To the many other contributors who may not be listed by name, grateful acknowledgment is also due. It is hoped that the chapter will be useful to the practicing mining engineer who suddenly is assigned to marine work or to the experienced marine engineer who is equally suddenly assigned to mining work. It is not possible to put "everything-you -need-to¬-know" into one section, but. the very full bibliographies at the end of the text should adequately fill in for those who wish to know more. 20.1-THE MARINE ENVIRONMENT Marine mining is set apart as a separate discipline by the marine environment. The following subsections describe the environment from the point of view of the physicist, the chemist and the geologist. The interrelationship of these disciplines with the economic mineral potential of the oceans and seas is apparent from the description of the marine mineral resources. The marine environment is an extremely complex natural phenomenon with which the marine mining engineer must learn to live. It can be the source of his wealth or his frustrations and sometimes both. It can never be ignored.

Jan 1, 1973

By J. J. Komadina

Since the advent of resin-in-pulp (RIP) technology for treatment of uranium-bearing ores in the 1950?s to current carbon-in-pulp (CIP) processing of gold values, metallurgies and operators alike have wrestled with the problem of interstage screening. Early gold CIP plants such as at Homestake utilized externally mounted vibrating screens in conjunction with air lifts to effect carbon-pulp disengagement. Other operations world-wide have likewise adopted this technique with varying degrees of success. Subsequent development of in-tank launder screens both in South Africa and the United States have been of the air cleaned variety (EPAC)

Jan 1, 1988

By K. A. Natarajan, M. R. Sabari Prakasan

"Biodegradation of sodium isopropyl xanthate using two types of bacterial strains, Paenibacillus polymyxa and Pseudomonas putida, is demonstrated. At concentrations higher than 50 mg/L, the presence of xanthate in the growth medium resulted in bacterial toxicity, retarding growth kinetics. Adaptation through serial subculturing in the presence of higher xanthate concentrations resulted in the development of xanthate-tolerant bacterial strains. Stress proteins secreted by bacterial cells grown in the presence of xanthate were isolated. Bacterial cells could utilize xanthate as a growth substrate, degrading xanthate species in the process. Acidic metabolic products generated by bacterial metabolism promoted efficient xanthate decomposition. Probable mechanisms for the biodegradation of isopropyl xanthate are illustrated.IntroductionDifferent types of alkyl xanthates (ethyl, isopropyl, amyl, etc.) have been used as flotation collectors in the concentration of sulfidic ores for several decades. Large quantities of waste water and xanthate-containing effluents are generated by ore flotation processes, posing considerable environmental challenges. Billions of cubic meters of such process waste waters are produced annually across the world, most of which are discharged to the environment, often without any treatment. Leakages and accidental release of xanthate reagents from manufacturing plants and during transportation and storage can also contaminate the environment. Residual concentrations of xanthate reagents are encountered in waste effluent, which are found to be toxic to aquatic life and unfit for human consumption (Harris, 1984; Okibe and Johnson, 2002). Further, direct recycling of such waste waters for plant operations can compromise water quality standards required for process operations. The presence of residual xanthate in recycled waters from flotation plants deleteriously influences flotation processes. Xanthate can be easily decomposed at low pH values; however, CS2, which is more toxic, will be produced by the acidification of neutral and mildly alkaline xanthate-containing solutions. Physico-chemical methods such as flocculation, chemical oxidation and decomposition and physical adsorption used to remove residual collector reagents from mill process waters are often expensive and not environment-friendly (Oliveira and Rubio, 2009; Cheng et al., 2012; Molina et al., 2013,)."

Jan 1, 2015