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The US Constitution provides for regulation by the states for protecting the public's safety, health, and welfare. Hence, in the eyes of the law of all states today, this is the sole justification for registration of professional engineers. Wyoming was the first state to register professional engineers in 1907, to correct abuses of incompetent or fraudulent practices in surveying and real estate. Public safety and health are most directly affected by civil, electrical, and mechanical engineering. Other branches of engineering have a profound effect on the public welfare, including investors, and safety and health of employees. No arguments, pro or con, are valid except in relation to the registration laws of various states. Code of Ethics Few would argue the desirability of requiring conformance with a code of ethics. A major problem lies in enforcing compliance, since protecting the public demands a high standard of competence, yet assessing competence gets confused with restraint of trade. Bidding engineering work on price competition can lead to pressure to cut corners on engineering quality, and was therefore discouraged by codes of ethics. The Supreme Court, in a suit against the National Society of Professional Engineers (NSPE), barred any engineering society from such bidding restriction. It has, however, upheld the right of states to impose codes of acceptable practice as part of registration laws. For example, Texas Canon I reads, "The engineer's paramount professional responsibility should be the safety, health, and welfare of the general public." Anything less makes the code practically meaningless, but there are potential conflicts of interest in many engineering organizations. How can conflicts be handled? Any corporation could improve its public image by adopting a policy that each employed PE should, without fear of recrimination, record in writing over his seal any problem or flaw in any design that comes to his attention. The policy should further require that his superior provide him a written reply pointing out that the "flaw" is accepted as requiring correction or as a calculated risk, or overruled as erroneous or as a difference of opinion. Errors in calculation of judgment are inevitable. Despite this, there are limits to how much time and money should be spent to eliminate them. It is difficult, however, to see any excuse for failure to conscientiously evaluate the opinion of a PE. This may be an impossible ideal, but how else can the profession or the industry have credibility? The National Council of Engineering Examiners (NCEE) has a code of ethics one presumably subscribes to by signing an application to write a Principles and Practices examination. However, NCEE has none of the power of enforcement that is available through state boards of registration. Registration Qualifications Qualifications are set by the laws of the states. In general, they require passage of an eight-hour examination in fundamentals, preferably at graduation, and, later, one in principles and practices. The examinations are compiled and distributed by NCEE. This system provides for a high degree of uniformity and reciprocity. States set the education and experience levels (typically four years after graduation) required by those desiring to write the principles and practices examination. Examinations The principles and practices examination calls for answering eight of 20 equal weight questions; one on engineering economics, 19 on engineering. Economics may enter into engineering questions, but only provided the question is not answerable by an economist without engineering training. In preparing examinations, NCEE strives to use questions that require some judgment and can be more effectively answered by someone with four years experience beyond college. The aim is to assess entry-level professional

Jan 2, 1984

By Thomas P. Kwiatkowski, Joginder S. Bhore, Christopher D. Orlandi, Jose Velez

Three case histories of successful TBM tunneling for New York City Water Tunnel No. 3 are presented. The tunnels, costing about one billion dollars total, are the 5-milelong, 18'-11" OD Brooklyn Tunnel; the 5-mile long, 23'-2" OD Queens Tunnel, and the9-mile long, 12'-4" OD Manhattan Tunnel. The three tunnels are the first major tunnels constructed in New York City rock utilizing the TBM method of construction. This paper describes and compares the three tunnel projects in terms of geology, construction methods, TBM’s, rock and groundwater behavior, rates of advance and other performance data, and challenges and solutions encountered during the projects.

Jan 1, 2007

By Peter Amelunxen, Craig Lockhart

Significant effort was made in 2003 and 2004 to upgrade the existing instrumentation and process control infrastructure at the Phelps Dodge Bagdad copper concentrator. Specifically, • cameras were installed on the feed belt for online image analysis data, • ultrasonic level sensors were installed for froth height and sump level control, • a trial froth image system was installed on one of the rougher rows, and • a new expert system to tie everything together was integrated and tuned in-house. Control philosophy, observations, opinions, and general tips and tricks are discussed with the hope of assisting other plant personnel and expert system integrators.

Jan 1, 2005

By Steven Norris, William Moler, Michael Cole, Patrick Doig, Debi Lewis, Craig Pyle, Matthew Crow

The recently completed Lower Northwest Interceptor Program (LNWI) in Sacramento, California comprises, ten pairs of micro tunnels totaling 4,369 m (14,417 ft),three horizontal directionally drilled bores totaling 956 m (3,154 ft), and two large diameter tunnels under the Sacramento River totaling 1,198 m (3,953 ft). This paper briefly summarizes surface and subsurface conditions, and planning and design considerations. It then goes on to describe problems encounterd with each trenchless crossing, as well as lessons learned with respect to shaft construction, ground control at shafts during tunnel break-in and break-out, frac-out and heave, settlement, obstructions, coordination with permitting agencies, and application of geotechnical baseline reports.

Jan 1, 2007

By M. van Elp, R. Saitua Nistal, P. J. M. Groot

Demand for construction raw materials depends on investment in housing, other buildings and infrastructure. The provision of these materials requires early knowledge of future trends in construction investment. By using scenarios possible future developments and bandwidths can be explored. Policy makers in government organisations as well as in the private sector can base their policy decisions upon these insights. In this paper we discuss the case of sand and gravel in the Netherlands. We will show that, depending on the future role of government and the degree of internationalisation, the long term demand for construction raw materials will strongly diverge. Nevertheless there are some common developments such as a decreasing population growth, a smaller share of the labour force in total population and a growing wealth. In different scenarios we will encounter different conditions for minerals provision and for sustainable development.

Jan 1, 2011

Worldwide minerals exploration slipped in 1992 from 1991 levels. Although industrial production figures showed the US economy emerging from recession in early 1992, it was not until February 1993 that the lagging indicator of unemployment dropped to 7%. Most other industrialized countries are still in recession. Preliminary data for 1992 showed industrial production dropping in Japan (5%), Germany (1.4%), the United Kingdom (0.5%) and France (1.4%). The slowdown in industrial production led to reduced mineral demand. This resulted in lean cash flows from mining operations, which squeezed exploration funding. Although mineral prices were steady during most of 1992, some mineral commodity prices began falling in late 1992 and early this year. Exploration 1991-1992 According to Metals Economics Group (MEG), planned 1992 exploration expenditures were down by about 5%. Geographically, the leading exploration target was the United States with 21 % of the expenditures, followed by Australia (19%), Canada (18%), Latin America (15%), South Africa (9%) and the western Pacific (7.5%). The remaining 10% was split between Europe and Africa. There were absolute increases in exploration expenditures in the United States and Latin America. Latin America showed the largest increase. The change in the Mexican mining law allowing foreign ownership of mines should result in the inflow of direct foreign investment in Mexico's mining industry.

Jan 1, 1993

By Dilip I. Patel, Jesus Schabib, W. Allen Mawr, Daniel A. Louis

East Side Access (ESA) will extend Long Island Rail Road into midtown Manhattan via 11 km of tunnels, a new terminal station and associated rail support facilities. The hard-rock tunneling in Manhattan will traverse under Park Avenue and some of the most historically and commercially significant real estate in the world. The soft-ground tunneling in Queens will traverse beneath Amtrak’s Sunnyside Yard and the Harold Inter locking, the busiest rail interlocking in North America. This paper details ESA’s program-wide geo-instrumentation monitoring system for obtaining, processing and presenting all geotechnical monitoring data. Data streams will be real-time, such as from automated total stations, and manually read, such as from optical survey instruments and handheld data loggers. All data will be input into a web-based Geo-Instrumentation Data Management System, which will be accessible to project stake holders via ESA’s intranet or via the Internet using remote access controls.

Jan 1, 2007

By J. Wiese

Recently the operating philosophy at concentrators processing platinum bearing ores has started to move from a recovery dominated system to one in which the production of high grade concentrates at the expense of some recovery would provide greater benefits in the further upgrading of the platinum group minerals (PGM). The low grades usually obtained are associated with the presence of naturally floatable talcaceous gangue minerals in all PGM ores. Polysaccharide depressants such as guar gum and carboxymethyl cellulose (CMC) are used to improve the grades of the concentrates. Recent testwork has shown that the use of high depressant concentrations can prevent any naturally floatable gangue from reporting to the concentrate. The only gangue present in the concentrates would be due to its entrainment in the froth. Under these conditions much higher grades can be achieved. The sulphide minerals themselves, however, become susceptible to depression at high depressant concentrations. This work examines how the recovery of sulphide minerals in two Merensky ores was affected by the type and concentration of the collector in the presence of high depressant concentration (500 g/t) and that the response of the sulphide minerals was also dependent on the type of depressant used (guar or CMC).

Jan 1, 2009

By Dean Brox, Jason Morrison, Peter Procter

The Galore Creek Mine project is one of the newest major mining projects underdevelopment in Canada. The project is located in a very remote area of northwester British Columbia and is being developed by Nova Gold Resources of Vancouver. The mine project comprises one of the largest and highest grade undeveloped porphyry-related gold-silver-copper deposits in North America. In order to access the mine site anew 120 km road is planned to be constructed including a 4.4 km mine access road tunnel. Glaciers with heavy snow pack cover approximately two-thirds of the tunnel alignment with a maximum cover of 1,200 m. The size of the access road tunnel is about 50 m2 and has been designed as a large single lane road tunnel to accommodate the transport of large size mining equipment for mine start up and ongoing operations. The rock conditions along the tunnel alignment comprise very strong volcanic rocks. Key services for mining operations will be incorporated into the tunnel comprising diesel and power as well as the concentrate pipeline. Structural portal canopies have been incorporated into the tunnel design due to the risk of rockfalls and avalanches in the portal areas. The mine access road tunnel is a significant and critical-path component to the overall project to provide vehicular access to allow construction of the mine site. In order to meet the expected mine start up date the construction of the tunnel works are to commence prior to any other works at the mine site and will be constructed entirely by helicopter support. Geotechnical investigations commenced in the summer of 2006 with the removal of the overburden materials at the portals to assess bedrock conditions. Tunnel construction from both portals is expected to commence in the spring of 2007. The construction of the mine project is subject to and awaiting environmental approval in the spring of 2007. The mine access road tunnel will be the longest private road tunnel in North America. The key design and constructability issues for the mine access road tunnel project are presented and discussed.

Jan 1, 2007

By G. Lawrence, R. Pieters, A. Leung, T. Pedersen

The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of a new 3-yr research program with three primary goals: 1) understanding controls on metal concentrations in the lakes; 2) using mesocosms to test a variety of remediation strategies; and 3) verifying and improving an existing coupled physical-geochemical model with the goal of improving predictions of pit lake water quality. Initial data from two summer surveys in the Main Zone pit lake reveal elevated dissolved metal concentrations (e.g. [Zn] as high as 800 µg/L) present in a two-meter-deep mixed layer, and elevated particulate metal concentrations towards the bottom of the water column. Hydroxide sludge, a byproduct of ARD treatment, is being discharged to the surface waters of the Main Zone pit lake. The sludge sinks rapidly to the lake bottom, leading to deep waters with elevated levels of dissolved O2 and total metals. By contrast, the deep waters of the proximal Waterline pit lake are mildly reducing, manifested by depletion of O2 and elevated levels of dissolved Fe. These reducing conditions have led to elevated levels of As (up to 1500 µg/L) in Waterline pit deep waters. The contrasting behavior of these two pit lakes, as well as the processes controlling metal concentrations in the lakes, will be discussed.

Jan 1, 2002

By F. M. Jenkins

Improvements in miners? safety and health, as reflected by injury and illness statistics, have reached a plateau and even been reversed. Research into miners' OSH is a necessary adjunct to regulatory enforcement. Under the National Occupational Research Agenda (NORA) mining experts have come together to draft a national agenda for this research. The Mining Sector Council, one of ten NORA Sector Councils, has produced a draft national research agenda to guide all mining research entities: academia, government, and industry. The agenda has seven major objectives, each of which has a sequence of sub-objectives: Reduce the likelihood of disasters in mines; Improve mine disaster response; Improve the health of miners; Improve atmospheric control (ventilation) in mines; Improve health and safety through behavioral research; Improve mine design, systems operations, and management performance to enhance mine health and safety; Apply ergonomics, human factor engineering, to increase health and safety. Long-term maintenance of the Mining Research Agenda requires input from the public, both here and abroad, monitoring of the impact of research results using OSH data, and partners who will translate the research to practice.

Jan 1, 2012

By Jafar Khademi Hamidi

The Zagros long tunnel is one of the main components of Sirvan water transfer project in western Iran. It is approximately 48 km in length and consisted of two lots. The second 26 km lot of this tunnel is under construction by a 6.73 m diameter double shield (DS) TBM. The tunnel passes through several formations with wide range rock mass qualities. During the tunnel alignment, changes in rock quality were highly frequent from poor to very good. The encountered geological conditions required TBM operation to change frequently from hard rock to soft, dry to flowing, sticky to nonsticky ground (and vice versa), more often than expected. In the course of tunneling, the machine has encountered nearly many adverse geologic conditions. The most important problems have been sudden high volume water inflow into the tunnel, sticky ground, and gas seepage, all of which resulted in reduced TBM advance rates. This study will high-light two difficult ground conditions including large water ingress and sticky ground and also the related problems encountered by the TBM along 8 km of excavated tunnel. In sticky grounds, cleaning of the clogged cutter head caused many delays and contributed to additional downtime. Application of some operational modifications, including decreased TBM thrust showed satisfactory results in such cases. While reduced thrust resulted in reduced penetration rate, but the overall TBM advance was greatly improved by the increase utilization rate and elimination of down time related to cleaning of the head. To cope with high water inflow, application of preventive measures such as pre-grouting has proved to be a more efficientsolution. The sealing of ground water inflow also decreased seepage of dangerous H2S gas and other chemicals such as hydrocarbons accompanying the groundwater.

By C. K. Kocsis, S. Hardcastle

Mine ventilation, requires electricity to operate the fans and fossil fuel for heating. Typically, this accounts for approximately 40% of the overall underground energy consumption. This is considerable, and one of the major causes of this expense is that most mine ventilation systems are designed for the "worst-case-scenario" with respect to ventilation demand, which is commonly dictated by diesel equipment usage. Once designed, mines tend to operate their ventilation system at this peak level despite their exceeding day-to-day development and production needs due to lack of appropriate ventilation controls. In underground metal mines, TeleminingTM, which includes the tele-remote operation of mobile development and production equipment from surface, will change the mine design criteria including its support infrastructure such as the ventilation system. With the removal of machine operators to surface control rooms, conventional ventilation systems designed to dilute and remove pollutants can become redundant. Depending on the ultimate need for ventilation, its cost in automated mines with tele-remote equipment operated from surface will be lower than the cost of ventilation in conventional mines. These cost savings, which could be significant, would not only come from the ability to reduce the amount of ventilation in the mine, but also through the capacity to automate its distribution. This paper provides an indication of the new airflow requirements in stopes and dead-end developments for the tele-remote and automated mining processes based on climatic modelling. Furthermore, this paper makes a cost benefit analysis by comparing the ventilation system operating cost of a conventional underground metal mine based on the mobile diesel powered equipment design criteria with the newly redesigned ventilation system operating cost of an automated mine based on the "heat management" design criteria.

Jan 1, 2002

By J. Drelich, C. L. White, Ch. Zhou, W. M. Cross, E. T. Zellers, E. M. Nadorny

A laser-based particle deposition (LBPD) technique has recently been developed at Michigan Technological University for patterning mesostructures made of nanoparticles and their clusters. The LBPD technique makes use of laser induced optical forces to transport and pattern nanoparticles on a variety of conductive and non-conductive substrates from nanoparticle-in-liquid suspension. A weakly focused laser beam is used to confine and propel particles along the laser beam. Confinement is accomplished by forces due to optical field gradients that act on polarizable particles and tend to move them to axis of the laser beam. The force propelling the particles along the direction of the laser beam arise from momentum conservation of photons scattered from the particles. In this paper, this novel LBPD technology is briefly reviewed, and several examples of patterning are presented. The size and morphology of mesostrips produced from gold and polystyrene nanoparticles, under a range of deposition conditions, have been characterized by optical microscopy, atomic force microscopy, and scanning electron microscopy. The results presented here demonstrate that gold and polystyrene nanoparticles deposited by LBPD can form clusters of particles. When deposited at an appropriate rate, such clusters can form multilayer mesostrips of high particle density. One goal of research on such systems is to fabricate arrays of parallel lines made up of colloidal particles having a range of surface functionalities. Such arrays have potential for application as novel microsensors for environmental sensors.

Jan 1, 2003

By D. R. Babich, E. R. Bauer

National Institute for Occupational Safety and Health (NIOSH) researchers are conducting a cross-sectional survey of equipment noise and worker noise exposures in the mining industry. Surface and underground limestone is one commodity recently surveyed. The sound levels of mining and processing equipment were recorded to identify noise sources. Full-shift worker noise exposures were completed to determine the exposure of various occupations. This paper presents the results of the noise research conducted in both underground and surface limestone mines, detailing the equipment likely to cause worker overexposures, and the occupations experiencing overexposures. Implications for worker noise exposure reduction are also reported.

Jan 1, 2006

This paper evaluates the effect of longwall mining on a cluster of unconventional shale gas wells located in a district barrier pillar between a current longwall panel and the future panel north of the barrier pillar. A cluster of 19 unconventional shale gas wells have been drilled and 5 additional gas wells have been proposed in the barrier pillar. The closest gas well is 25.6 m (84 ft) to the current panel tailgate and 26.2 m (86 ft) to the tailgate of the future panel north of the barrier pillar. The rib-to-rib width of the barrier pillar is 57.9 m (190 ft). The distance between the two gas wells across the barrier pillar is 6.1 m (20 ft). The pillars in the current tailgate are on 22.9-m (75-ft) and 32.0-m (105-ft) centers, and the pillars in the tailgate of the panel north of the barrier will be on 22.9-m (75- ft) and 36.6-m (120-ft) centers. The two longwall panels adjacent to the barrier pillar are 475.5-m (1,560-ft) wide. The overburden depth at the shale gas well site is 321.6 m (1,055 ft). The wells have been installed in the barrier pillar, and the current district panel and subsequently the panel north of the barrier will be developed and retreated in the near future. The average min

Jan 7, 2020

By Michelle Stokes, Alexandra Miller, Campbell McKenzie

"The ancestral Ringarooma River in northeast Tasmania has transported alluvial tin and other heavy minerals from their onshore source of stanniferous Devonian granites downstream into what is now Ringarooma Bay. Previous exploration work has demonstrated the presence of potentially economic tin mineralisation within the palaeochannels and terraces associated with the submerged river.The offshore tin resource lies directly on the seabed or with less than 2 m of overburden, and within 5 - 50 m water depths in the wider bay area. The main river channel continues offshore for at least 13 km, with high tin grades found within the palaeochannel but also dispersed across the sea floor as a sheet wash, a result of Quaternary sea level change reworking the placer deposits. This drowned portion of the coastal plain contains a continuation of rich tin leads as low gradient anastomosing channels, and has been delineated by marine seismic and drilling activity since the 1960s. Tin grades in the Tertiary and Quaternary alluvial profiles vary from 50 - 300 g/m3, with the highest concentrations in the coarser basal horizons. A previous offshore explorer estimated a resource of 194 Mm3 at 150 - 250 g/m3.Kenex Ltd created 3D models of the paleochannels and the mineralisation with the aim of better constraining the resource estimate and identifying additional depositional areas. The modelling was undertaken with the input of geophysical data, bathymetry and geochemical sampling of the seabed surface and from historic offshore drill holes. A prospectivity model covering Ringarooma Bay was produced to target tin-bearing gravels. Predictive maps were created to represent various features of the offshore mineral system, including assessing gradient changes in palaeochannels and their sinuosity. The model identifies areas with higher potential for alluvial tin mineralisation and will be used to focus the exploration programme over tenements currently held by Kenex Ltd."

Sep 1, 2014

By J. Leinart

As is readily apparent, the reliability of the early-stage costs estimated for any mining project are critical to the viability of that project. An estimate too high might leave a potentially profitable deposit undeveloped or worse yet, available to a competitor. One too low might waste investment dollars in a project not yet economically ripe. There are two aspects critical to any estimate: 1. The cost data used to represent the values of the wages, salaries, supplies, and equipment. 2. The design used to determine the engineering parameters upon which the above estimated values are based. Given that all of the information contained in Mining Cost Service is provided by suppliers, equipment manufacturers and mine operators, one wonders why there is any question as to the reliability of cost estimates developed using this information. Given that it is all actual (as opposed to statistically derived) data, where do the problems with estimate reliability lie and what is the impact of the data on that reliability? The following presents a series of analyses designed to assess the reliability of the cost estimating process. Both the actual cost data and the engineering parameters upon which they are based are examined in an attempt to quantify and understand the importance of each. While several sources of cost information are available (Means, Richardson, Primedia?s Equipment Watch, and individual suppliers and manufacturers), the following rely solely on data contained in InfoMine USA, Inc?s, Mining Cost Service and in its Sherpa Mine Cost Estimating Software.

Feb 27, 2013

By M. A. Trevits

Mine seals are used in underground coal mines throughout the United States to isolate abandoned mining areas from the active mine workings. The objective of adding inert gas to a sealed mine area is to quickly reduce the oxygen concentration in the sealed area to a level that will not support combustion. In the US, this process is typically conducted from the ground surface and because surface-to-mine access is constrained by so many variables, it is very difficult to provide a source of inert gas to the place where it is needed underground. To alleviate this problem On Site Gas Systems, under a NIOSH contract, built a nitrogen (N2) generation plant that operates in the underground environment. The purpose of this work was to create a reliable in-mine mobile plant that would extract N2 gas from the mine atmosphere and use the gas to create and maintain a safe sealed mine area. The plant is based on a novel design using pressure swing adsorption technology and is sized to fit on a standard shield car or mine dolly for easy transport in and around an underground coal mine. The plant is capable of producing about 900 scf/min of N2 gas at ambient mine conditions. After an exhaustive series of laboratory tests, the plant was field tested at the NIOSH Safety Research Coal Mine (SRCM) where a portion of the mine was sealed and rendered inert. During the test, the movement of the injected gas was monitored at several underground points to observe the progress and extent of the inerting process. This paper describes the plant design and the results of the field test at the SRCM. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of NIOSH.

Jan 1, 2009

By D. P. Richards

Tunneling in carbonate sedimentary rocks such as lime stones and dolomites can be difficult when solution channels or voids are anticipated. Addressing the risk aspects associated with these formations can be done effectively through the Geotechnical Baseline Report (GBR) by properly characterizing the ground and ensuring that the Owner?s and the Contractor?s interests are represented and protected. This paper presents a review of tunneling difficulties in these rocks and includes a review of site investigations, geologic characterization, and presentation in the GBR. Key construction issues are also discussed, including appropriate excavation technology, mechanisms of face support and groundwater control, and quantifying grout takes.