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By J. M. Schisler

In the last five years Eldorado Resources Ltd. (ERL) has undergone a major expansion and modernization of its uranium refining and conversion plants. A new refinery for processing yellow cake to UO3 was constructed at Blind River in northern Ontario and started up in 1985. Its rated capacity is 18,000 t/a uranium as UO3. At Port Hope, Ontario, ERL's new UF6 conversion plant has been constructed. This plant started up in 1984. It utilizes the novel, wet-way process to produce UF4 and gives the company a UF6 production capacity of 14,500 t/a U. Also at Port Hope is Eldorado's ceramic UO2 powder production facility, commissioned in late 1980. It has a capacity of 1700 t/a uranium as UO8. With the completion of these capital projects, Eldorado has the largest and most up-to-date refining and conversion facilities in the western world. This paper reviews the refining process and process design. The methodology used to start up the Blind River plant is described as are some startup difficulties, solutions that were developed, and the resultant current operation.

Jan 1, 1987

By William C. Larson

The number of uranium in situ leach operations has increased significantly since 1975. As of May, 1980, there were a total of 27 active projects, including 16 commercial scale operations (or under construction) and 11 pilot scale operations. The south Texas uranium district and Wyoming have been the most prominent areas in early field experiments as well as in commercial application of this new recovery technique, although in situ leach tests are now being conducted in Colorado and New Mexico. The growing number of commercial-scale operations is accepted as prima facie evidence that in situ mining now offers a third option along with open pit and underground mining for winning uranium from sandstone host rocks. It is estimated that in 1979 about 9 percent of the nation's total uranium production was from in situ mining. However in situ mining of uranium is not without its environmental controls. The primary emphasis of environmental controls falls into two catagories; namely, control of the leach solutions during mining and demonstration of ground water restoration. Finally this paper briefly reviews the Bureau of Mines research program in uranium in situ mining.

Jan 1, 1980

By Peter Mason, Chris Walker, Mike Costello

The Phase I electrowinning system at KCGM's Fimiston Operation utilised the well proven technology of electrowinning precious metal values onto steel wool followed by calcining and direct smelting to bullion. The above process, while reliable and successful, was to some extent labour intensive. The Williams Mine in Ontario, Canada had published conditions under which precious metal values are electrowon onto woven stainless steel and directly removed using high pressure sprays. The current paper describes the testwork which was carried out to check the applicability of the Williams criteria to KCGM eluates arising from the elution of highly loaded carbon from the calcine circuit and lowly loaded carbon from the float tails circuit. Information is also given on the commissioning and opera­tional experience which occurred.

Jan 1, 1996

By Willaim A. Berg

Vegetative stabilization can help meet the esthetic objections and pollution problems posed by mine wastes. However, mine wastes are often unfavorable growth media and special treatments and techniques are needed for plant establishment and continued growth. The establishment of vegetation on mine wastes was the subject of many papers presented at the International Symposium on Ecology and Revegetation of Drastically Disturbed Areas held at Pennsylvania State University on August 3-16, 1969. This paper is a summary of those papers presented at the symposium that dealt with the nutritional and physical aspects of plant establishment on a variety of mine wastes. The synopsis presented is a combination of excerpts from the abstracts, notes on the oral presentations, and rough drafts of some of the papers. The papers will eventually be published in the symposium proceedings.

Jan 1, 1970

By Valerio Violo, Antonio Raschilla, George Kafantaris

"The Cityringen project in Copenhagen, Denmark will form a new circular line in the city center and will consist of 21 new stations (17 + four transfer stations) and approximately 31 km (19 miles) of earth pressure balance (EPB) twin-bored tunnels.The new tunnels passed under the historical building of Magasin du Nord, McDonald’s and two pubs in the heart of the city with a minimum cover of about 4 m (13 ft).To minimize the movements, a complex system of compensation grouting and jet grouting soil treatment was performed. A detailed action plan between the parties involved allowed coping with the critical tunnel boring machine’s (TBM) successful passage.The Cityringen is an extension of the existing metro line underground Copenhagen and will include the City Circle Line, 15 km (9.5 miles) of twin tunnels looping around the city. The City Circle Line will form a new circular track inside the city center and will intersect the existing M1 and M2 lines at Kongens Nytorv and Frederiksberg stations, as well as suburban train services at København H, Østerport and Nørrebro. It will extend the Metro network to the Nørrebro, Østerbro areas and the central station at København H (Fig.1). The two new lines M3 and M4 will run on the same tracks, but the M3 will be a circle route running around the entire line, whereas the M4 will drive from the station to the north side of the city.The €1.5 billion design-build contract was awarded by Metroselskabet in January 2011 to the Copenhagen Metro Team (CMT), a joint venture (JV) between the Italian companies Salini, Tecnimont Civil construction and Seli SpA. Since the bankruptcy of Seli SpA and Tecnimont, Salini Impregilo now owns 100 percent of the JV shares. Seli Tunneling Denmark ApS, a subcontractor to CMT, was initially constituted as a Seli SpA subsidiary and, following the economic difficulties of Seli SpA, was acquired in 2015 by Salini Impregilo. Seli Denmark is in charge of the tunnels excavation and lining and owns the four 5.84-m (19-ft) diameter Seli/Kawasaki earth pressure balance machines."

Jan 5, 2017

By Dennis F. Koschak

Production tests at Reserve Mining Company's iron ore pelletizing plant established that rubber-lined balling dm produce a green pellet equivalent in quality to those produced in conventional balling drums equipped with reciprocating cutter bars. The flexing action of the rubber liner prevents concentrate buildup in the drums, eliminating the need for a cutter bar. Advantages of the rubber-lined drum includes a reduction in maintenance and operating manpower, reduced bentonite consumption with less drum surging, reduced power consumption, and improved drum on time.

Jan 1, 1983

By D. Olsen

The paper discusses the legislative and practical approach adopted to problems of management of environment in relation to coal mining in a very sensitive area of the south coast of New South Wales. The environmental problems are complicated in this area due to multiple and very often conflicting land usages. The environmental approach in relation to water quality maintenance, noise control and air quality is discussed and methods adopted meet stringent requirements. Requirements of New South Wales Regulations on Environmental Impact Statements (EIS) are described.

Jan 1, 1988

By C. W. Schultz

The distribution of material passing a screen, or a set of screens, is described by the equation [ ] where p = the probability that a single particle will pass the screen on a single presentation k = number of layers of screen cloth n = distance from head of screen expressed as number of screen openings. This model can be used to predict the performance of conventional screening operations (i.e., k = 1) as well as the so-called "statistical screening" operations. Using this technique, in which multiple identical layers of screen cloth are employed, screening can be carried out at a finer size than is possible with conventional techniques with no loss of separation efficiency.

Jan 1, 1969

By A. E. Ketler

Powerful, yet inexpensive, personal computers running Windows-95 operating systems provide powerful mine-wide monitoring capabilities when properly engineered. Long awaited conductivity over LAN, phone and Internet links provide new dimensions for sharing information throughout an operator's organization, in- deed around the world. On-line data analysis, archival data storage and historical trend viewing generate shared inputs to production, safety and maintenance personnel. Five years in development, Rel-Tek's new EZ-Trol/W-DX system was engineered around the pilfalls of a Windows environment. It now offers higher speeds, 3D animated graphics and long distance telemetry - all with better reliability than ever before possible. The ubiquitous DDS utility inherent in most Windows was discarded in favor of a lightning fast RAM format. Several ponderous interpretive programs were redesigned into a single compiled entity, thus avoiding the overhead from message conversion, handshaking and transfer. To make the system user friendly, a 'Wizard" utility helps operators set up and reconfigure their systems on site. In-mine data acquisition telemetry was also re- vamped, incorporating a unique noise avoidance scheme, dubbed the "DX" bus - enabling longer distances and higher reliability. 12- bit analog conversion provides the enhanced resolution needed for field scaling auto-cal sensors. By mid '96, eight EZ-TROLMI- DX systems were up and running, several for more than a year. Factory updating and assistance are possible over a phone or Internet link. Our factory testing of components routinely includes actual operation at 2400 BAUD over 14 miles of twisted pair wires.

Jan 1, 1997

By Sean Peterfreund, Grant Finn, Ty Jahn

For urban underground development involving tieback anchors for excavation support, authorities having jurisdiction typically require tiebacks to be de-tensioned before project completion. This paper updates “A Proactive Approach to Tieback Anchor De-tensioning” (by Peterfreund and Finn, published in the 2017 RETC Proceedings), which discussed a new method employed in a cut-and-cover transit station project. Since publication of that paper, 237 tiebacks were successfully and rapidly detensioned from using a small-diameter drill to cut strands from the surface. To the authors’ knowledge, this was the first intentional large-scale use of a drilling method for this purpose.

Jun 13, 2023

By Janet E. Lamarre

Current statistics show that 90% of new-business failures are caused by the unsuitability of the entrepreneur for the business he has started. Are you a suitable candidate for success as a consulting geologist? Should you start your own geologic consulting business, and when? This paper investigates the demand for consultants with respect to general economic trends and mineral exploration activity trends. Furthermore, the study reveals certain technical skills and personal characteristics important to the success of the consulting geologist. Research shows chat certain expectations which prompted geologists to change careers are fulfilled while other unanticipated expectations often are also met.

Jan 1, 1985

By Wayne F. Crockett, Martin H. Col

Gold, as a precious metal, has been sought for several thousand years. During this time economics have generally determined whether or not a deposit is minable. Today, few would spend $500.00 or $1,000.00 to produce one ounce of gold, yet most gold deposits currently being mined would have such costs if they were mined using the methods of the 18th century. Innovation has been the key to success in the world of mining. We are constantly having to look for new ways to mine deposits of lower grade, at greater depths, or with higher stripping ratios. The mining of placer gold deposits has always been subject to the volatile swings of the world price and the constant rise in production costs. The rise in costs is compounded by the drop in overall ore grades. Occasionally, a major technological innovation will dramatically reduce the costs of placer mining to allow previously marginal or unminable deposits to be mined at a profit. The continuous bucketline dredge was the last such major innovation in the gold placer mining. The continuous bucketline dredge has allowed large volumes of placer deposits to be picked up and processed on a continuous basis. Unfortunately, as the overall grade of the deposit declines, it becomes impossible to process enough ore to pay for the operating costs. There are many gold deposits around the world waiting for the next technological innovation that will allow them to be mined. One such deposit has been the Grey River deposit near Greymouth in New Zealand. The deposit contains gold reserves of 8992 kg, yet the deposit has been sitting idle for many years because the average value

Jan 1, 1988

By J. D. Morgan

The US economy grew steadily in 1989, reaching an annual rate of $5.3 trillion in the last quarter (US trillion=1012 ). The value of domestically processed, mineral-based materials rose 5% to $315 billion (US billion=109). The value of metals produced from US ores rose 14% to $11.6 billion, while industrial minerals rose 2% to $20.2 billion. Recycled scrap was valued at $10 billion. Increasing economic activity stimulated metal prices. Yearly lows and highs were $2.31 and $3.56/kg ($1.05 and $1.62 per lb) for copper, $1.58 and $2.57/kg (72 and $1.17 per lb) for aluminum, 77 and 97 cents/kg (35 cents and 44 cents per lb) for lead, and $1.58 and $2.09/kg (72 cents and 95 cents per lb) for zinc. Many mining and metal companies reported reasonable profits. Consumer demand strongly affects mining because the US economy is saturated with long-lived products. Consumer, mortgage, and Federal debt continued to rise. 250 million US citizens already possess 172 million licensed motor vehicles and 100 million dwelling units. New car production fell 4% to 6.8 million units, while truck and bus production fell 1 % to four million units. New housing starts fell 9% to 1.4 million units. Imports supplied a significant proportion of total US consumption of several important mineral materials. Imports of crude and refined petroleum costing $50 billion exceeded domestic crude oil production. President Bush expressed "strong concerns about this country becoming further dependent on foreign oil." And the Department of Energy held a series of hearings around the country to develop ideas for a "national energy strategy."

Jan 1, 1990

By Jeffery Leavy, Ken Davis, Kirk H. McDaniel

The Waste Isolation Pilot Plant (WIPP) is a United States Department of Energy facility located in southeastern New Mexico. It is designed for the safe disposal of transuranic radioactive waste in deep geologic salt beds. Westinghouse TRU Solutions, LLC, the managing and operating contractor, undertook a project to simulate the processes at WIPP in order to identify bottlenecks and optimize available resources. The activities simulated in the model included the receipt, processing and disposal of radioactive waste underground, the mining of new areas for future waste disposal and the transportation of salt out of the mine. The complexity of the processes and the interactive requirements between processes required the use of advanced modeling techniques. The simulation model includes a huge number of locations and path network node points, with movement to and from the locations controlled using parameters rather than explicit routing. Information for the timing and sequence of the mining and nuclear waste emplacement operations is brought into the model via spreadsheets. Arrays in the simulation model keep track of past and future events that occur. Routing to the multiple possible positions in the underground mine is done using attributes, and system functions within ProModel in order to allow for a highly flexible sequence of planned events and to reduce the level of effort in creating the ProModel processing. Considerable use of subroutines in the simulation model is utilized for parametric decision-making that is repetitive. This presentation describes the modeling techniques used to accurately simulate the surface and underground operations. The surface and underground operations are considerably different, thus they will be treated in their own sections.

Jan 1, 2002

By Wilbur C. (Original by) Helt

Throughout the history of mankind, the principal use of coal has been to produce heat through combustion. The heat is used in many ways: to warm air space for our comfort; to provide heat or energy to power industrial processes, such as cement and steel production; and to produce electricity. Because it is our nation's most abundant fossil energy fuel, coal in the late 20th century is on the threshold of becoming a significant source for synthetic liquids and gas energy fuels for this country. This is made possible by conversion processes which can change solid coal into various synthetic gases and liquids. These coal-derived fuels are nearly identical to the processed fuels and chemicals provided by natural gas and crude oils, which presently provide almost all the petrochemical feedstocks and energy fuels needed for the residential, light commercial, and transportation markets. A revolution is beginning to take place, not only in the United States, but in many other countries with a return to a coal-based energy economy. Also, new combustion and conversion technologies which are compatible with national health and environmental goals are rapidly emerging. These technologies will allow coal's use to be expanded not only in its traditional markets, but also to supply markets held by natural gas and crude oil. With the worldwide decline in natural gas and crude oil reserves, coal is being-looked upon to meet the energy demand. Because of these new coal conversion technologies, coal will no longer be only a combustion fuel, but a valuable raw material for production of a variety of clean fuels and chemicals.

Jan 1, 1981

By T. T. Gronfors

The excavation process and equipment used for excavation join firmly each other. By changing the process or method, the construction of equipment may be altered essentially. It has been possible to develop a wholy new type of hydraulic boom for tunnelling, when only parallel drilling instead of V-cut is used. The utilization of controlled blasting has made small holes more desirable. So the controlled blasting has had an influence on the selection of drill steel equipment and in this way also influenced the construction of the equipment.

Jan 1, 1970

By Frank Matter

Production of ultrafine powders of industrial minerals has been a problem in the past. In recent years new wet and dry grinding stirred ball mill systems have emerged which have been commercialized Two such systems are the TRZK mill with double step air classifier for dry grinding and the NRZK mill for wet grinding The primary features of these mills are feed entering from top and the product along with the grinding media leaving from the bottom, and a media separation and recycle system A detailed description of the NRZK mill for grinding coal is presented

Jan 1, 1983

By Rashi Tiwari, George Danko, Jeremy Knowles

A control technique is described for enhancing the efficiency of materials handling and other mining operations. The concept involves human-operator and robotics control interactions to assist in mining operations. Many mining tasks require a human operator to coordinate the motion of several machine links by simultaneously manipulating multiple joysticks or other control devices. The new control architecture allows for automatic coordination of multiple machine joints. The machine movement may follow a computer-optimized, learned coordination pattern, while the operator still retains the master control of the overall trajectory and velocity parameters. Examples are described for a surface mining front shovel.

Jan 1, 2005

By A. S. Astakhov

Working out of the production calendar plans (schedules) at deep mines which provide for the interaction of all kinds of mining operations determining coal output growth and mining and technical indices is a striking example of mining art. However, multi-variant decision making, a sophisticated system of integration, as well as high labour consumption for calculation and graphic operations in calendar planning require the improvement of traditional techniques and the development of new methods for calendar planning of mining operations at deep mines. The following specific aims were pursued in developing a computerized system of calendar planning (scheduling) of mining operations.

Jan 1, 1979

By Harold L. Kike

Until recently sulphur uses were so broadly based that economists used sulphur consumption to measure industrial activity. However, sulphur use patterns are changing and the manufacture of phosphate fertilizers presently accounts for approximately 65% of the world's sulphur consumption compared with only 25% in 1960. This has encouraged the development of new agricultural and industrial uses for sulphur. Major emphasis has been placed on its use as a fertilizer and in the manufacture of paving materials, specialty concretes and coatings. Some of these uses could have a significant impact on future sulphur usage.

Jan 1, 1986