Search Documents

By K. V. Godfrey

With the increasing need to exercise better control over mill circuits has come a requirement to develop rapid, accurate means of measuring circuit parameters. One of the most important parameters is the assay of the material in the circuit (or about to be introduced to the circuit). To date, most on-stream analysis has been performed using X-ray fluorescence equipment. Neutron activation offers an alternative method in certain circumstances, and one which has several interesting advantages. Recognizing the need for a simple, safe neutron activation unit suitable for on-stream analysis in the mineral industries, Atomic Energy of Canada Limited has designed, built and tested the SHERLOCK system. One prototype (SHERLOCK I) is located in Ottawa and is now used primarily in research. A second prototype (SHERLOCK III) is located in Vancouver at the laboratories of B.C. Research. This unit is being used for some development research and for evaluating the unit in specific applications. Most of the work completed to date has been aimed at proving the technique and in developing some of the parameters needed to design systems for a milling plant. Funding for the work has been through research grants and through sponsor¬ship by interested companies.

Jan 1, 1971

By J. P. Kennedy

Process data managers or historians are recognized as essential for reengineering projects in industrial plants. With increasing automatic data collection, the knowledge of how to use these data profitably grows as well. This paper is a summary of the data historian and its components plus examples of benefits including environmental reporting, performance monitoring, and exception reporting to management.

Jan 1, 1994

Ground falls (roof and rib) have historically been responsible for nearly 50% of all fatalities in bituminous underground coal mines. In recent years, the number of some annual ground fall fatalities has approached zero, indicating that significant progress has been made. On the other hand, the twin disasters at Crandall Canyon in 2007, in which nine miners perished in violent coal bumps, provided a stark reminder that complacency is premature. One important success has been a great reduction in the number of miners killed inby roof supports. Throughout the 1990s, these accounted for nearly half of all roof fall fatalities, but there have just been two inby incidents since 2005. Progress has also been made in pillar recovery, where there has been just one fatal incident since 2005. On the other hand, more than 300 miners continue to be injured each year by rock falling from between supports and 100 more are injured by rib falls. Together, these two categories also account for a large percentage of recent ground fall fatalities available technologies such as roof screen, rib bolting and inside control roof bolters could reduce injury and fatality rates if they were used more widely. Further advances in these areas will likely be the next big advance in ground control safety.

Jan 1, 2011

By James Westfield

I welcome this opportunity to appear before you and to review briefly the various health and safety services of the Bureau of Mines available to the mining industry, other than coal, and also to tell of our plans for extending these services to improve safety and health conditions. The Bureau's health and safety activities are basically services by which we attempt to develop and disseminate information on improved techniques in mine accident prevention and promote mine safety education in the mineral industries. Unfortunately, some mining companies, particularly some of the smaller operations, seem to be unfamiliar with these services, The Bureau of Mines is charged by law with the responsibility for inspecting coal mines; other services to the coal mining industry and are provided only on request, Safety inspections and other services that we offer are provided for noncoal mining industries solely upon request.

Jan 1, 1958

By Bruce D. Hebb, Shahin Shadlou

Fiber Reinforced Polymer (FRP) is an excellent material choice for a broad spectrum of corrosive fluids and, in many cases, offers the best value per dollar. FRP Flanges present the greatest design challenge of all standard piping components. The theory underlying the design of flanges is very complex. In addition, due to the nature of FRP material, proper fabrication of the flanges is as critical as the design. In this review, the challenges of making FRP flanges along with the design techniques and best practices of fabrication that will lead to a high-quality flange will be discussed.

Feb 1, 2024

By N. A. Karl, D. R. Wilburn

"This summary of international mineral exploration activities for the year 2015 draws upon information from industry sources, published literature, SNL Metals & Mining (SNL) (Charlottesville, VA) database and specialists in the U.S. Geological Survey (USGS) National Minerals Information Center. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry, and presents analyses of exploration activities performed by the mineral industry.Three types of information are reported and analyzed in this annual review of international exploration: budgetary statistics expressed in U.S. dollars provided by SNL; regional and site-specific exploration activities that took place in 2015 as compiled by the USGS; and regional events that affected exploration activities including economic, social and political conditions, which were derived from published sources and discussions with USGS and industry specialists. Commodity and regional compilations are presented in this summary. Because multiple sources were used to develop commodity and regional compilations, statistics may vary depending on the source and type of data that are being reported.The SNL data summarize planned company budgets for worldwide exploration activities in 2015 for 24 nonfuel mineral commodities and metal alloys and are based on company surveys. Surveys focused on precious metals (gold, platinum-group metals and silver), base metals, (cobalt, copper, lead, molybdenum, nickel, tin and zinc), bulk commodities (bauxite, chromite, iron ore, manganese, phosphate and potash), and other commodities (diamond, graphite, heavy-mineral sands, lithium, niobium, rareearth elements (REE), tantalum, tungsten and uranium).USGS data compilations and analyses are based on information provided by USGS mineral commodity and country specialists, as well as industry contacts and published trade journals. The USGS data summarize exploration site data collected for more than 80 minerals and materials, with a focus on base metals, diamond and precious metals. The USGS analyzed available information to assess the level of exploration activity in 2015 and to report trends in mineral exploration activity for the period 2005 through 2015. These analyses identify where mineral exploration is occurring by commodity and region and the intensity of activity that is taking place in each region for selected mineral commodities, and determines those factors that most affect changes in exploration activity."

May 1, 2016

By R. R. Klimpel

This paper describes a series of mechanical flotation cell results run with various chemical reagent schemes designed to economically improve the flotation performance associated with selected industrially available coals. The emphasis is on the identification of practical flotation methods of processing coals containing unusually coarse and/or fine feed sizes, of increasing the recovery of oxidized and/or difficult to float coal, and of increasing the selectivity of coal over pyrite in high sulfur coals.

Jan 1, 1991

By Lance Rasband, Richard Hanke, John Starcevich

"Mining on Seattle’s SR99 tunnel began in July of 2013. Initial mining progressed slowly through a 4.5 m (14.9-ft) thick fiber-reinforced concrete headwall before immediately entering the first of three planned safe havens. Once through the headwall and safe haven the machine would move through roughly 122 lineal m (400 ft) of jet grout improved soil at a rate of slightly more than 1.6 m/d (5.3 ftpd). It was anticipated that once mining has passed through the improved area, “Bertha” – now the world’s second largest tunnel boring machine (TBM), would be moving at a rate of almost 11 m/d (36 ftpd). By the end of October 2013, Bertha had mined roughly 131 m (430 ft), averaging 1.4 m/d (4.7 ftpd), and had begun mining within native soils. By the start of December 2013, tunneling had reached the 244 m (800 ft) mark and Bertha was averaging 3.6 m/d (11.9 ftpd), achieving as much as 12.8 m (42 ft) of progress on given days. Unfortunately, on Dec. 6th, 2013, Bertha began to stumble and all progress quickly came to a halt.Initial reports stated an obstruction had stopped Bertha in her tracks. The preliminary investigation involved installation of 10 deep dewatering wells to reduce the hydrostatic pressure within the ground around the TBM, to allow the contractor’s personnel to inspect the cutter head from within and also to investigate for the presence of obstructions at the face of the cutter head. During inspection, the contractor’s crews found fragments of steel pipe entangled in the cutter head. The steel was apparently from an abandoned 254 mm (0.9 in.) diameter monitoring well casing, previously installed by the Washington State Department of Transportation (WSDOT) to monitor groundwater conditions for the design and planning of this tunnel project. After the steel was removed from the cutter head and cleared from Bertha’s path, she attempted to move forward but was only able to generate a slow crawl."

Jun 1, 2016

By CORA ROELOFS

In the USA, miners are at higher risk for work-related disorders that could precipitate an opioid prescription, injury-related opioid prescriptions, and opioid overdose. We aimed to support prevention of these outcomes with an “opioid hazard awareness” miner safety training module. In January and February 2020, the training module was embedded within required mining safety and health training for stone, sand, and gravel miners in Massachusetts (USA). Training impact and reception were assessed with a pre- and post-training survey of trainee characteristics, training content knowledge, and attitudes. Over 800 miners were trained and over 600 responded to surveys. We found statistically significant improvements in opioid risk factor knowledge and knowledge of resources to help a coworker. Nonstigmatizing attitudes were high both at baseline and following the training. The training was perceived as relevant and useful by trainees. Improving opioid hazard awareness in high-risk worker populations has potential to reduce opioid dependence and downstream impacts including overdose death. Employer injury-prevention efforts should be reinforced while worker health and safety training enhances awareness of opioid-related harms and prevention strategies for miners and other high-risk worker populations.

Nov 19, 2021

By Z. Hyder, M. D. Cleason

"INTRODUCTION Mine Ventilation has come a long way over the years. The main purpose of mine ventilation is to keep conditions in the mine safe for the worker so that the mine will be productive and profitable. Technological developments to the mine ventilation system itself and the development of mining techniques have helped improve the safety and productivity of the miners and the mine. Most of the developments to mine ventilation and to safety devices came as the result of serious mining disasters. Another effect of those mining disasters, especially in the late 19th century and after, was legislation to set specific safety standards for mines, especially in the underground coal mines. This paper will focus on the connection between mines disasters and the mine safety legislations promulgated because of those disasters. A BRIEF HISTORY OF MINE SAFETY LEGISLATION Mine legislation has a long history in the U.S. dating back well in the 1800’s. However, mine safety legislation is considerably newer. In 1891, the U.S. Congress passed the very first version of mine safety legislations setting up minimum safety standards. By today’s standards, the 1891 legislation was incredibly basic (7). It took a series of horrific mining disasters for Congress to take action a second time. In 1910, Congress established the Bureau of mines. The role of Bureau developed and changed over next 60 years. In 1995, Congress voted to disband it (27). Initially the Bureau was only charged with investigating and coming up with ways to reduce accidents in coal mines. It was not until 1941, when Congress formally allowed Bureau of Mines’ Inspectors into the mines. In 1947, the Congress enacted and adopted a set of federal safety regulations for the inspectors to follow (1). Finally, in 1952 Congress granted the Bureau of Mines the authority to inspect the mines and to issue citations and/or orders of withdrawals. This act was known as the 1952 Coal Act and the penalties were limited to civil penalties. It would take a couple more iterations of mine safety legislation for monetary and criminal penalties to be introduced (10). Up until 1966, mine safety legislation was directed primarily at underground coal mines and surface coal mines. Congress passed the Federal Metal and Nonmetallic Mine Safety Act of 1966, thus providing a set of standards for all mines to follow (1). The 1952 Coal Act was amended again to be the Federal Coal Mine Health and Safety Act of 1969. This amendment was the beginning of modern mine safety legislation (13). In 1973, Congress created what can be considered the first ‘version’ of the modern day MSHA (Mine Safety and Health Administration). The initial version was the Mining Enforcement and Safety Administrations or MESA. Congress created MESA to act as the enforcement agency, relieving the Bureau of Mines of that responsibility so they could focus on their initial purpose, the development of countries natural resources (14). As mining industry grew, mine safety and health became a greater concern and priority. More efforts were put in legislating the industry. The Federal Mine Safety and Health Act of 1977 provided the platform for today’s mine safety and health legislation. Under the Federal Mine Safety and Health Act of 1977, also known as the Mine Act, MSHA came into being (1)."

Jan 1, 2016

By Walter H. Schwedes

Ore grinding mills are really just slowly rotating barrels, but barrels that are growing in size so fast that the application of electric drives for them is rapidly approaching a technology like that for wind tunnels or pumped storage drives. This application is particularly worthy of care because some 40% of the 75 megawatts of power used by a large copper ore concentrator, or some 60% of the 200 megawatts supplied to a large iron ore concentrator, are for grinding. These ore plants are located where the ore is, not where a utility happens to be. So, the challenge is not only to choose a drive and .power transmission for reasonable cost, high performance, reliability and minimum maintenance, but to afford the interface between mill drive and power distribution and source systems to minimize the whole ore plant's monthly power bill, or costs of self generation. Conclusions can be reached in optimizing a drive selection only for each particular ore plant's set of parameters, but by identifying the criteria for selection and then weighting each type of drive per criteria, yardsticks for final choice become apparent. This is the purpose of this paper. Grinding action takes place inside the barrel, where the ore charge is ground with the aid of balls, or mill length rods, or large chunks of ore as in autogenous grinding.

Jan 1, 1972

By R. N. Powell

The Pipeline ore body was discovered in March 1991. The construction of the new mine and mill did not start until early March of 1996. Upon completion of permitting and corporate project approval, the 289 million USD project was “fast tracked”. The commissioning began 11 months after start of construction and the project ended 40 million USD under the budget figure. The objective of this paper is to review and highlight the Pipeline Project history from discovery, design, lawsuits, permitting, and re-design through to current - 1998operating practices. Particular emphasis will review the process design, design mistakes, and design successes. The paper will review project history, feasibility, design concepts, operator training, construction, financial and the current operation. Additional discussion will review what design features worked and which did not work within the process plant.

Jan 1, 1999

By Timothy J. Orr, Robin J. Burgess-Limerick, Jennica L. Bellanca, MARGARET E. RYAN

Powered haulage continues to be a large safety concern for the mining industry, accounting for approximately 50%of the mining fatal accidents every year. Among these fatal accidents, haul-truck-related accidents are the most common, with 6 of 28 and 6 of 27 fatal accidents occurring in 2017 and 2018, respectively. To better understand why these accidents continue to occur and what can be done to prevent them, researchers reviewed the 91 haul-truck-related fatal accidents that occurred in the USA from 2005 to 2018 and performed bow-tie analyses using the final reports published by the Mine Safety and Health Administration. The analyses explore the context of the accidents with a focus on the initiating event, event outcome, hazards present, and possible preventative and mitigative controls. Overall, the vast majority of the accidents resulted in a haul truck colliding with the environment, and the majority of these events were initiated by loss of situational awareness or loss of control. The majority of the hazards were related to design and organizational controls. The results of this study suggest a need to investigate operator decision-making and organizational controls and to focus on improving design and operation controls such as mine design and operational procedures.

Feb 22, 2021

By Magnus Ericsson

The unexpectedly quick recovery in world crude steel production in the second half of 2009 was due almost entirely to increased production in China that began in late 2008. Previous peaks in monthly production in China were matched by April 2009. The rest of the world had still not reached pre-crisis production rates by May 2010. Chinese production drives growth, but there has been some growth in most other larger crude steel producing countries as well, compared to production in 2009. If the production rate of the first four months of 2010 continues, the total output of crude steel in 2010 will be somewhere around 1,410 Mt (1.5 billion st), the same as in the record year of 2007.

Jan 1, 2010

By Lukas Walder, Roland Arnold, Raphael Zuber, Richard Gradnik

This paper presents the construction of the ventilation shaft for the single-tube, doublelane Kramer tunnel. The project is located in the Federal State of Bavaria, Germany. This road tunnel, which has been under construction since December 2019, is the key component of the western bypass of the town of Garmisch-Partenkirchen. Once completed, it will relieve the town’s central district from enormous volumes of traffic. The contractor is the joint venture named ARGE Kramertunnel consisting of BeMo Tunnelling and Subterra. The whole project will be completed and handed over to the project owner, Staatliches Bauamt Weilheim, in 2023. The opening of the entire bypass section including the tunnel to traffic is planned for 2024. The tunnel, with a total length of 3,609 m (2.24 miles) and an estimated cost of EUR 178 million incl. VAT (US-Dollar 201 million), is designed as a single-tube, double-lane structure with one traffic lane for each direction of travel. The safety issue that exists for singletube tunnels is solved by a parallel escape tunnel passable for vehicles. For tunnel ventilation, an intermediate shaft has been designed with a depth of approximately 90 m (295 feet) and an inner diameter of 4.5 m (14.8 feet). All tunnels and ducts are excavated according to the principles of the New Austrian Tunnelling Method (NATM). The geological and hydrogeological conditions, the change in the profile (from round to square geometry), and also the shaft being located at a high elevation presented a demanding technical and logistical challenge. The site arrangement with the pit bank was located in a cut, the slopes of which had to be stabilized with shotcrete and soil nails. This excavation was carried out from the fall of 2020 to the beginning of 2021 because construction operations had to be completed outside the nesting period of protected birds.

Jun 13, 2023

By Jon J. Indall

I. INTRODUCTION The challenge of moving the use of nuclear energy from military to civilian use was first issued by President Dwight Eisenhower in his December 8, 1953 “Atoms for Peace” speech delivered at the United Nations. Eisenhower stated: “The United States knows that if the fearful trend of atomic military build up can be reversed, this greatest of destructive forces can be developed into a great boon, for the benefit of all mankind. * * * * The more important responsibility of this Atomic Energy Agency would be to devise methods whereby this fissionable material would be allocated to serve the peaceful pursuits of mankind. Experts would be mobilized to apply atomic energy to the needs of agriculture, medicine, and other peaceful activities. A special purpose would be to provide abundant electrical energy in the power-starved areas of the world. In the 1950’s and 1960’s, the Atomic Energy Commission promoted the use of nuclear power as the answer to our nation’s energy problems. Nuclear power would provide energy too cheap to meter. The utility industry responded and numerous plants were planned with over one hundred constructed from the 1970’s to the 1990’s. Capital costs for nuclear power plants escalated due to permitting changes and public opposition, and the Three Mile Island incident caused new nuclear plant construction to cease. Today, we once again are experiencing a nuclear renaissance. Concerns over global warming and rapid projected increases in the demand for electricity have caused many nations to begin construction of new nuclear fleets. The price of uranium to fuel these reactors, which had dropped to an historical low of $7.10 in 2001, has surged to $56.00 as of October 2006. This paper will review some of the social, environmental, and government issues that are all playing a role in the resurgence of the nuclear fuel industry.

Jan 1, 2007

By H. Dreissen

Upgrading of low-concentration ores is of growing importance today. The Heavy Medium Cyclone Process, thanks to strong centrifugal forces, effectively separates particles varying only slightly in specific gravity but widely in size. The paper discusses the separation efficiency, the method of assessing that efficiency, and the influence of such factors as medium solids. The operating results of nine heavy medium cyclone plants handling following minerals are reported: barite, wolfram, iron, magnesite, diamond, lead-zinc, fluorspar, rocksalt potash. Highlighted are an improved recovery system for heavy medium and some other developments, such as techniques for separation down to 0.1mm and the application in the field of recycling.

Jan 1, 1980

By D. R. Wilburn

his summary of international mineral exploration activities for the year 2011 draws upon available information from industry sources, published literature and U.S. Geological Survey (USGS) specialists. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents [ ] analyses of exploration activities performed by the mineral industry. Three sources of information are reported and analyzed in this annual review of international exploration: 1) budgetary statistics expressed in U.S. nominal dollars provided by Metals Economics Group (MEG) of Halifax, Nova Scotia; 2) regional and site-specific exploration activities that took place in 2011 as compiled by the USGS and 3) regional events including economic, social and political conditions that affected exploration activities, which were derived from published sources and unpublished discussions with USGS and industry specialists.

Jan 1, 2012

By V. A. Evans

The preparation of a paper reporting fluorspar economics in the United States at one point in time could have been somewhat complicated be- cause of the number of producers, both large and small, that derived production from different locations throughout the Western U. S. and the Southern Illinois and Western Kentucky fluorspar districts . Companies such as Allied Chemical and William- son Mining operated in the Jamestown district of Colorado. In Walden and Salida, Colorado, the Colorado Fluorspar Company operated mines and mills.

Jan 1, 1986

By Yun Bai, Sarah Wilson, Michael Salcher, Mark Trim

Over the last decade more than 62 miles (100 km) of civil transport tunnels were constructed in Sydney, Australia, using the sequential excavation method (SEM). The WestConnex motorway tunnels, each stage of which used over 20 roadheaders to excavate up to 40 tunnel headings, had numerous caverns up to 100 feet (30 m) wide and 82 feet (25 m) high. SEM tunnels in North America typically have far fewer active headings. This paper examines the differences in scope and risk allocation for construction phase services, including comparison of the Permit to Tunnel (PTT) process in Australia and the Required Excavation and Support process in North America.

Jun 23, 2024