Search Documents

By Jun Ho Lee, Dae Young Kim, Ebrahim Farrokh, Ki Chang Hyun

"The Jinhae Geoje gas pipeline tunnel project is the largest (7.8 km) and the deepest (90 m) subsea tunnel in South Korea. This tunnel will house a pipeline to carry natural gas from the mainland to Geoje Island southeast of the country to alleviate the increased demands for natural gas, especially in the winter season. Tunneling is currently underway using two slurry shield TBMs of 3.5 m diameter. This paper describes the major design elements of the tunneling machines and their performance evaluation. For this purpose, a thorough analysis of geotechnical information was performed to evaluate the tunnel elevation to reduce the risk of tunneling under high water pressure in unstable and permeable rock mass under 9 bar water pressure. TBM specification and TBM performance were also analyzed using different methods, including well-known models as well as a rotary cutting machine test developed in house in Hyundai Engineering and Construction Company. INTRODUCTION High demand for natural gas, especially in winter season was the primary driving factor for the design of the Jinhae Geoje gas pipeline project. This project is located southeast of South Korea between Jinhae district and Geoje Island and runs for over 50 km length. The mid part of this project includes a 3.5 m diameter subsea tunnel consisting of two sections of Geoje to Jiri Island (4.3 km) and Jinhae to Jiri Island (3.5 km). Figure 1 shows the tunnel project location and its layout. Figure 2 shows the geological profile along the tunnel. As can be seen, the tunnel passes mainly through three rock types: granite, tuff breccia, and andesite tuff. This tunnel was planned to be constructed by two face pressurized shielded TBMs and to be lined with a segmental lining of 2.8 m internal diameter. The major challenge for this tunnel is its maximum expected water pressure at the tunnel invert (8.83 bar). At such a high water pressure, the TBMs required special design to ensure they can handle unexpected water pressure and to ensure the risks for the TBM maintenance intervention are minimal. In this regard, a thorough analysis was conducted on the TBM design parameters and geotechnical information to define required TBMs’ design parameters and to identify the safest tunnel elevation. This paper provides a brief overview of the project geotechnical information, TBM selection and its design specification, tunnel elevation selection, and TBM penetration rate evaluation. In this regard, a rotary cutting machine testing equipment was used to perform trial tests on a similar rock type encountered along the tunnel for performance evaluation and optimization."

Jan 1, 2016

By T J. Napier-Munn, T Perkins

The JK Drop Weight test was developed at the Julius Kruttschnitt Mineral Research Centre (JKMRC) in the early 1990s as a means of characterising ore for the purposes of AG/SAG mill and crusher modelling. It has since been used extensively worldwide in the minerals industry as a key ore characterisation test which produces parameters which are used in comminution circuit design and optimisation. The test generates three parameters which are used in the AG/SAG mill model of the JKSimMet software. The resistance of the ore to high energy (impact) breakage is quantified with the A and b parameters. The oreÆs resistance to low energy (abrasion) breakage is measured using the ta parameter. The accuracy and precision of the results of the JK drop weight test are of great importance given that the parameters are key inputs in the design of such capital intensive items as SAG mills. Plant optimisation exercises also rely on the accuracy of the parameters to assist with improving the performance of an existing circuit. A thorough analysis of the accuracy and precision of the parameters generated by the JK drop weight test has now been undertaken by JKTech Pty Ltd (JKTech). An experimental program was designed using statistical methods to plan a hierarchical set of 24 drop weight tests on homogeneous material. Each stage of the test was identified and incorporated into the experimental design so that the contribution to the overall error of each stage could be quantified, including the effect of operator. The data were analysed by nested analysis of variance. An overall analysis of the A, b and ta parameters generated from the test program has now quantified the variance of these parameters more thoroughly than ever before. Using the results for the impact parameters, an analysis has been carried out to investigate the effect of these variances on final SAG mill comminution circuit design. The results will also be used to refine the comparative testing procedures currently in use by licensees worldwide.

Jan 1, 2008

By Mike Higgins

"Data management is emerging as a major concern for miners. Engineers today are faced with anextensive array of data from varying sources, and are required to consolidate and analyse thisinformation to produce an effective and efficient mine plan. The viability of a mining operation canbe dependent on the outcomes of this process. With so much at stake, it is no surprise that mostengineers prefer a standard approach to blasting which is designed to minimise risk rather thanoptimise performance."

Jan 1, 1998

By Mike Higgins

"The purpose of mining and its related industries is the removal of, and usually the subsequentprocessing of, material from the earth. This includes mining for minerals, quarrying for stone, and civilexcavations. Where this involves rock, the most common method is to fragment the rock by blasting. "

Jan 1, 1997

By Y Gu

The Mineral Liberation Analyser (MLA) employs the technologies of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The use of backscattered electron images to define phase boundaries produces very high resolution image analysis and subsequently detailed and accurate particle images and data output. The mineralogy, elemental deportment, grain size, liberation characteristics and mineral associations of a large number of samples can be described. The MLA uses a comprehensive set of analysis methods to meet a wide range of applications. The data from ore characteristion projects completed during feasibility studies are important aids for effective plant design. The MLA can be used to establish variation in the mineralogy of an orebody, identify and quantify the deportment of deleterious elements, and provide valuable information to support comminution and flotation test work. In established plants the MLA data is an important component of plant survey work and monthly composite samples. Changes in feed characteristics and/or operating conditions can be monitored and solutions to any deterioration in recovery and grade performance found. The MLA has extensive applications in the minerals industry. Rare and precious metal samples can be accurately measured using high-resolution grey-scale images. Several new measurement techniques have been developed to perform rapid searches of a large number of samples to provide efficient and accurate analyses of fine-grain, low concentrate material. Quantifying the mineral variability in mineral sands operations is essential to maximising grades and recovery. The MLA produces particle-based data on density, mineralogy, size and shape and has developed measurement techniques to provide the elemental quantification required for the characterisation of these deposits. Nickel sulfide ores can be analysed to provide modal mineralogy, elemental deportment and liberation and locking data. The low-grade and variable nickel mineralogy of these deposits makes the use of quantitative mineralogy an essential component of maximising returns. Coarse particle measurements preserve the in situ textures of ores and support flotation and breakage test work for feasibility studies. The deportment of penalty and bonus elements can be quantified and the association and grain-size data can be used to identify potential separation issues.

Jan 1, 2006

By R D. Morri, D J. Alexander

The design and optimisation of mineral flotation circuits is currently performed using a combination of laboratory, pilot plant and full scale testing. Owing to the variable nature of flotation circuits and the complex nature of the flotation process, it is difficult to interpret the data collected from flotation testwork. JKSimFloat is a computer modelling package which is being developed to interpret flotation testwork data collected at the various stages of the mining cycle. The parameters derived from the program can be used to assess potential circuit configurations in both the design of new flotation circuits and in the refinement of existing operations. The aim of this paper is to outline the modelling methodology used in JKSimFloat and to outline how it can be used effectively to model data collected from either the laboratory, the pilot plant or the existing flotation circuit. The use of flotation model parameters in circuit evaluation will be demonstrated via the use of a case study based on data collected from ComincoÆs Red Dog lead flotation circuit.

Jan 1, 1998

By Eric Jacobs

"Building and operating tunnels has been a highstakes endeavor in terms of costs, complexity, safety and impact on contractors, owners and the public for a long time. There are many variables that need to be closely monitored and managed to construct a tunnel on-time, on-budget and safely. Once built, there are also many elements that need to be monitored and managed to operate a tunnel safely and efficiently.Fundamentally, the risks to the safe and efficient construction and operation of a tunnel are a function of the degree of harm and the likelihood of the harm occurring. From a cyber security perspective, risk assessments used to inform decision makers and support risk responses are typically based on identification of relevant threats; internal and external vulnerabilities; the impact that may occur given the potential for threats to exploit vulnerabilities and the likelihood that harm will occur. This article focuses on creating awareness of vulnerabilities associated with technology used in tunnel construction and operation and some of the challenges associated with remediation of these vulnerabilities. As we all know, technology has been evolving at an accelerating pace and infiltrating every aspect of our lives in new and often exciting ways. In the world of tunneling, sensors and systems that provide position and time have become accurate, rugged and cost-effective enough to come out of the research labs and into the equipment and systems used every day. There are many opportunities to employ connected computing devices and sensors to costeffectively capture, integrate and analyze key data with minimal latency to manage risk better, improve safety and avoid surprises."

Jun 1, 2019

By Sam Messina

[Project: Job Number: Date: Superintendent: Person Making Inspection: Note: The following checklist shall be used on a regular basis as an overall assessment of the jobsite. The checklist is not all-inclusive. All applicable Federal, State, and local regulations, standards, and ordinances pertinent to the jobsite conditions must be evaluated on a continuous basis. Column A - Adequate Column I ? Inadequate]

Jan 1, 1998

By Gisele R. Passalacqua, Aly Mohammad, Joanna Smith

The $13 billion John F. Kennedy (JFK) airport construction redevelopment program includes new terminals and buildings that are supported on piles to meet the airport expansion demand due to increased travel. This paper presents a case history for JFK airport with main focus on construction activities and lessons learned. Challenges include limited head room, presence of underground utilities, and hard driving. Video inspection of pile proved very beneficial. In general, soil conditions at JFK Airport consists of sandy fill followed by a 5-foot thick organic soft layer. Below the organic layer, glacial sands occasionally mixed with gravel were encountered for great depth with increases in density with depth. The tapertube pile is an ideal choice for foundations with high capacity achieved through skin friction along the taper section. The piles are easy to splice to accommodate low head room. Pile Driving Analyzers (PDA), and Static Compression Load Tests were performed. The results of these tests are presented in this paper to illustrate the high pile capacity achieved. More detailed discussion and analysis of the test results will be presented in another paper related to the same project. Lessons learned from this project are shared to help the engineering community with future design and construction of similar projects.

AS we contemplate the bestowal of the John Fritz medal year after year on men of wide-world dis-tinction in the various fields of engineering, men who in one way or another have given impulse and direction to the progress of mankind, the question becomes inter-esting as to what manner of man was John Fritz and what were the qualities that singled out his name to be so conspicuously associated with the world's great scientific and industrial achievements. If, as Lowell said, it is the duty of the nation to pro-duce great men, our country surely rose to her oppor-tunity when she guided and guarded the career of John Fritz. Starting life as a blacksmith with no advantages of education, without influential friends or the favor-ing accidents of fortune, he advanced steadily in use-fulness, power and respect of his fellowmen until by common consent he occupied the first place in the domain of the steel industry of this, country. The numerous honorary scientific memberships conferred upon him in this country and abroad attest the esteem in which he is held by his fellow engineers. Twenty years after his retirement from active business at the age of seventy, he lived to enjoy, as few men have been permitted to do, the fame and the friendships which he had so amply earned. His sterner qualities of industry, integrity and sterling character were re-lieved by unfailing human sympathy, humor and spon-taneous good-will toward his fellowmen. To all who

Jan 3, 1928

By AIME AIME

THE John Fritz Medal Board of Award, at its annual meeting on Jan. 21, 1921, awarded its gold medal and diploma to Sir Robert Hadfield for the invention of manganese steel. On June 1, announcement was made that the Board of Award had awarded its gold medal and diploma to Charles Prosper Eughe Schneider for "achievement in metallurgy of iron and steel; for development of ordnance, especially the 75-mm. gun, and for notable patriotic contribution ' to the winning of the war." The award to Sir Robert Hadfield is for the year 1921; the award to Mr. Schneider is for 1922. The latter was made at this time in order that the medal might be presented by the group of American engineers now visiting England and France.*

Jan 1, 1921

"What is your history and how did you get involved in mining?Like many SME members, I came from a mining community with a family history in mining, in my case Walkerville, MT. Both of my grandfathers were underground miners. My father was a miner for a short time. He later sold drinks to the miners. Unfathomable by today’s standards, my dad would pick up the miners’ checks at the pay office and have them cashed and waiting with a shot and beer for the miners when their shift ended. My mother was a nurse, who from time to time, would patch up an unfortunate miner. I remember walking past multiple picket lines on the way to and from grade school, watching homes being boarded-up. I grew up with a deep respect for the critical relationship between labor and management.I had no intention of going into mining and initially set out to pursue a career in chemical engineering. But I attended my first two years of engineering at Montana Tech, due to the proximity and affordability. This is where I met Dr. Tom Finch, a mining professor who taught statics to the engineering students. After a coaching session in a hallway, half way through my sophomore year, I switched to mineral processing engineering. In his colorful way, Professor Finch advised me that, “You do not want to make #@*!! erasers and #@*!! Jell-O the rest of your life go talk to the guys in mineral processing.” He was very persuasive and here I am today.How about your involvement with SME?I encountered SME out of school and a little later in my career. Terry Maio and Jim Arnold invited me to local section meetings in the Missouri Lead Belt. That was my first exposure to the technical programming and relationship building that was possible at the local level. After Ozark Lead shut down and I relocated to Nevada, Rich Johnson, Scott Barr and Dave Collins encouraged me to attend my first annual meeting in Salt Lake City, UT. I joined SME at that time and was fortunate to be engaged by members like Art Schweizer and Jim Arnold, and I soon began the leadership progression for the Mineral & Metallurgical Processing Division. Since then, I have supported SME at the national and the local level serving in multiple roles and capacities."

Mar 1, 2017

By John Hays

AT the December Board meeting, the report of the William Lawrence Saunders Medal Committee, recommending the award of the medal to John Hays Hammond, was received and unanimously approved. The citation is: "For his notable work as an engineer and developer of mines at home and abroad, his industrial leadership and his public services." The medal will be presented as usual during the meeting in February, presumably at the annual dinner at the Waldorf, on Feb. 20. The other medals to be given on the same occasion are the James Douglas, which goes to Paul D. Merica, and the Robert W. Hunt, which is awarded this year to Edgar C. Bain, as already announced. This will be the third award made of the Saunders Medal for "Achievement in Mining," previous recipients having been David W. Brunton in 1927, and Herbert Hoover in 1928. The list is a distinguished one and Mr. Hammond's name is appropriately included. His career is so widely known that it is not necessary to repeat the account, published in MINING AND METALLURGY last April.

Jan 1, 1929

By Henry Carlisle

Henry Carlisle: This is November, 1960, and my good friend John Gustafson is sitting on the other side of a tape recorder. I, Henry Carlisle, am going to ask him some questions on the highlights of his life, and he has been good enough to say that he will play this question and answer game with me. Now, John, let's pick out a very interesting period when you went to North Labrador and made a preliminary investigation of the big iron deposits there. You were working for either Timmins or Hollinger, which was it? John K. Gustafson: I was in charge at that time of a Hollinger Exploration Co. office in Toronto. We had acquired options on enough shares to control Labrador Mining and Explorations Co., and through Hollinger North Shore Ltd., another company, we had a 3000 square mile concession in Ungava, Quebec, on the direct extension of the iron ore fields.

Jan 7, 1972

By AIME AIME

MINING geology has been at once the vocation and avocation of John M. Boutwell, newly elected Director of the Institute representing Utah and Colorado. Geologists were looked at askance by most of the "big" men in mining when, from 1896 to 1900. Mr. Boutwell was teaching geology at Harvard, his alma neater; and his success in applying geologic principles to the business of finding ore contributed much to changing the attitude of scepticism. From 1900 to 1908 lie was with the U. S. Geological Survey, with service in Bingham, Utah; Morenci, Ariz.; and Park City, Utah. Since then he has been engaged in private practice as a consulting mining geologist retained by many of the leading mining companies. A dozen men now recognized as outstanding geologists got their early

Jan 1, 1937

THE award from the fund established by Mrs. John-son, in memory of her husband, J. E. Johnson, Jr., to be given to some promising engineer, not over 40 years of age, because of meritorious research, inven-tion or contribution to the professional literature of iron and steel along the lines of blast-furnace process, has been given, for, 1928, to P. H: Royster. Mr. Royster was born at Raleigh, N. C., in 1888. and graduated from the University of North Carolina, in 1907, taking his A.M. degree at, the same school in 1908. He then went to Harvard where he continued research work in physics. After engaging for a while in commercial research in the turbine department of the General Elec-tric Co. and with Cutting and Washington he joined the staff of the Bureau of. Mines in 1916 and was assigned to work on the physical chemistry of the blast-furnace process. He worked with A. L. Feild on slag viscosity and they jointly presented-to the Institute the. papers on "Temperature and Viscosity Relations in the Ter-nary System CaO-A12O3-SiO2" (TRANS. LVIII, 658) and "Slag Viscosity Tables for Blast-furnace Work" (TRANS. LVIII, 650). He also presented a paper on "Production of Ferromanganese in the Blast 'Furnace" .(TRANS. LXII, 18), and jointly with T. L. Joseph contributed a paper on "Effect of Coke Combustibility on Stock Descent in Blast Furnaces" (TRANS. LXX, 236), and another on "Pyrometry in Blast-furnace Work" which was included in the special pyrometry volume published in 1920. The titles of these works perhaps sufficiently indicate the part Mr. Royster has played in the notable research work on the blast-furnace process carried on by the Bureau of Mines, and for which the committee recommended him to the Board of Directors to receive the Johnson award.

Jan 2, 1928

By Rita Aiello, Stan Mack, Peter Werth, Joseph McCarney, Jozef Stachulak

"Johnson Matthey has developed the first diesel particulate filter (DPF) for underground mining that controls particulate matter (PM) at the same time as maintaining emissions of NO2 at or below engine baseline levels. DPF technology is critical for controlling PM which is classified as a carcinogen, but passively regenerating systems rely on the use of oxidation catalysts that can potentially increase NO2 emissions. This paper reviews the development of low-NO2 PM control technology and the results from testing this technology underground on diesel mining equipment. KEYWORDS Decomposition catalyst, Diesel particulate filter (DPF), Diesel particulate matter, Mining Continuously Regenerating Trap (CRT®), NO2, SCR INTRODUCTION The introduction of diesel particulate filter (DPF) technology on heavy duty diesel (HDD) engines has been an important step towards addressing the clean air and health concerns for mining companies. Control of diesel particulate matter (PM) emitted from diesel engines is already being implemented for on- and off-road vehicles, and similar legislation is being prepared for mining equipment. In addition to PM, the diesel emission control strategies (DECS) also reduce carbon monoxide (CO) and hydrocarbons (HC). Some DECS control oxides of nitrogen, or NOx, which is composed of NO and NO2. Johnson Matthey has led the development of emission control technologies for diesel engines for almost 30 years. Over the last ten years alone JM has supplied over 3 million Continuously Regenerating Trap (CRT®) DPF systems for on-road vehicles, and over 200,000 systems for off-road vehicles. The patented CRT technology combines a diesel oxidation catalyst (DOC) with a DPF to effectively trap harmful PM from diesel exhaust, while removing CO and HC. The DOC converts part of the engine NOx to NO2, which reacts with the trapped soot to regenerate the filter. As engines become more fuel efficient, less waste heat enters the exhaust. This can be a disadvantage for after-treatment systems as it leads to lower catalyst operating temperatures. The CRT system regenerates passively, without addition of heat, at temperatures that are typical of diesel engine exhaust. JM recently launched the Mining CRT system which integrates CRT technology with NO2 abatement to reduce PM and tailpipe NO2 from underground diesel mining equipment. This is the first technology proven to control both PM and NO2 emissions for a cleaner, healthier working environment. The Mining CRT is also cost-effective compared to other technologies."

Jan 1, 2019

By R. A. L. Drew, F. Jalilian, M. Jahazi

Joining of superalloy Inconel 61 7 with a foil interlayer using transient liquid phase bonding (TLP) technique was studied. Inconel 617 is a solid solution, Ni - Cr - Co- Mo alloy with an exceptional composition of high temperature strength, oxidation, carburization resistance and thermal stability. In this investigation, two bonding temperatures, 1065°C and 1150°C, and two interlayer thicknesses with joining times varying from 5 minutes to 24 hours were employed. Experiments were carried out using nickel base interlayer (A WS BNi-3) with boron as the melting point depressant (MPD) element. Joints were characterized using optical microscopy, SEM, FEG-SEM, EBSD, XRD and microhardness. The results indicated that the rate of elimination of the liquid phase with increasing the bonding temperature, holding time and decreasing the thickness of the interlayer increased. The main precipitates in the diffusion layer had platelike and blocky morphologies for both bonding temperatures and all holding times.

Jan 1, 2006

By Sazol Das, Hany Ahmed, Ganesh Bhaskaran, Zhuoru Wu

"Friction stir welding (FSW) process in lap configuration for dissimilar materials has been developed and tested for steel to aluminum joining. A novel cylindrical tool was designed for improved material flow. The joining of steel to high strength 5xxx and 6xxx aluminum was carried out by FSW technique using optimized process parameters. The microstructure, micro-hardness, joint strength and corrosion properties at the weld interface have been investigated. Optical and scanning electron microscopy reveled a well layered structure at the interface and lap shear tests of the welds showed excellent fracture resistance. Neutral salt spray tests for up to 500 hours (ASTM B117) were carried out on the bare steel to aluminum FSW joints, which did not show neither evidence of corrosion at the weld interface, nor any degradation of the weld strength. The FSW lap configuration was applied to prototype commercial vehicle structural component whereby a steel stiffener insert was friction stir welded to high strength 6xxx aluminum alloy. The interface microstructure showed layered root without any steel shattering in aluminum side. A finite element study was carried out to quantify the benefits where it was found that the stiffness increases by 76% under bending loads and 36% in torsion loads.INTRODUCTION Energy preservation and environmental issues, namely carbon footprint and legislation around emission in transportation industries has led to a growing need to use of lightweight materials such as aluminum and magnesium alloys along with various grades of steel in structural application, while still maintaining their strength and crashworthiness. Assembling dissimilar materials within integrated structure is thus a stringent requirement related to optimum performance. In order to achieve an efficient technology of joining dissimilar materials such as aluminum to steel, it remains difficult to select an effective welding process for a given joint configuration. The use of aluminum in transportation industries for structural component is not exclusive in a design and is almost always used along with various steel grades for a mixed materials solution, thus dissimilar aluminum/steel lap joining is of great interest since this is widely used in the assembly of parts (e.g. pillar, frame rails, chassis, body in white (BIW), CAB, etc.)."

Jan 1, 2018

By S. K. Wu, Ray Y. Lin, Sunil Annaji

Infrared joining of TiAI using aluminum foils as the filler material was investigated at temperatures between 1050 °C and 1350 °C in a flowing argon environment for times varying between 15 and 60 seconds. Using aluminum foils, the attempt was to form the Al3Ti phase in the joint as a result of reaction between Al and TiAI at temperatures above the melting point of Al. It has been found based on X-ray diffraction and TEM analysis that, Al3Ti, indeed is the product of infrared joining of TiAI using Al as the joining alloy. Al3 Ti was detected even in the joint processed at 1050 °C for only 15 seconds. Since the aluminum foil used in this study contains 27 at% Si, the t 2 phase in the Ti-Al-Si ternary system is believed to have also formed at the joint/base TiAI interface. Cross sectional studies on the joined specimens have shown different degrees of reaction depending on the temperature and time of joining. Micro hardness evaluations across the joint show that the hardness near the center of the joint is typically smaller than that near the joint edge next to the base material. However, as the joining temperature and time increase, the increment of the hardness at the center of the joint is faster than that around the periphery of the joint.

Jan 1, 1996