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By Richard P. Killmeyer

In 1985 the Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy (DOE) conducted a study to evaluate the emerging selective agglomeration processes (Killmeyer, 1985). This paper covers a recent similar study evaluating an associated technology, the emerging advanced froth flotation processes. This study has goals similar to those of the 1985 study: to evaluate the emerging froth flotation technologies collectively and determine how far they have progressed in their ability to clean ultrafine coal, and to assess the differences among the participants. The major concern again in this study was not the level of development, nor the economics of each individual process but only the current technical performance.

Jan 1, 1989

By Kenneth N. Han

The effect of anions such as sulfate, chloride and nitrate on the solubility of rare earth element (REE)-bearing phosphates and fluoro-carbonates was examined using relevant thermodynamic data. The study found that these anions have significant influences on the overall dissolution of REEs from various sources in the aqueous media.

By Jon Y. Kaneshiro, Stephen J. Navin, Jerry Ostberg

In 1968, the U.S. Bureau of Reclamation awarded S.S. Mullen Construction of Seattle, the Intake Tunnel (488 m by 4 m diameter tunnel) and Pumping Plant No. 1. In1998, the Southern Nevada Water Authority awarded Lake Mead Constructors (Kiewit of Omaha) a parallel New Intake Tunnel (518 m long by 4.6 m diameter tunnel) and Pumping Plant. Both projects provide water to a thirsty Las Vegas. This paper presents a detailed comparison of the two intake tunnels in terms of grout takes and pressures, geologic mapping and rock quality, grout penetration beyond the excavation line, degree of fracture grouting, and groundwater inflow boundary considerations. The paper provides a comparison of grouting techniques and material developments then and now.

Jan 1, 2001

By Vincent A. Scovazzo

During the winter months of late 1985 and early 1986, residents along Dry Fork near Grundy, Virginia (United States) experienced seismic events that they attributed to longwall mining at Island Creek Corporation’s (Island Creek) Virginia Pocahontas Mine No. 3 (VP-3 mine). Island Creek contacted STS D’Appolonia Ltd. (STSDL) on March 7, 1986, to investigate these events. An STSDL representative, Vincent Scovazzo, interviewed residents of Dry Fork on March 10, 1986. It was noted that only people within a residential structure felt the events they described as house shaking, vibrating walls, and ceramics falling from shelves. STSDL representative installed a blast monitor at a residence. Within 2 days, various events were recorded. Some could be attributed to truck and heavy equipment movement. Eight events had no obvious cause but appeared on resident’s written logs as earthquakes caused by mining. STSDL contacted Utah Geophysical, Inc. who had developed a technique to determine the mode of rock failure using the seismic record. Utah Geophysical was engaged to install and monitor a microseismic network, locate the epicenter of the events, and work with STSDL in determining modes of failure. The network was comprised of six geophones located at five stations. Data was recorded for 24 days from May 20 through June 13, 1986. The data was filtered to eliminate events determined to have an origin other than the longwall panels’ overburden and under-burden. The larger events from this filtered data set were selected and analyzed to determine their hypocenter locations, time of occurrence, magnitudes, and failure mode. Processed data was interpreted, tabulated, and plotted by STSDL to provide information relative to the sources of the seismic vibrations and their possible relationship to the mining operation.

Jul 1, 2023

By M. K. McMullen

Mineral Development Agreements (MDA?s) are a cooperative mechanism in Canada by which the federal and individual provincial governments can coordinate their scientific, techno- logical and market development resources in order to implement measures designed to stimulate mineral exploration and development by the private sector; the objective, ultimately, being to increase the mineral industry?s contribution to provincial economies. In the latest round of MDA?s, which was initiated in 1984, a significant number of planned activities relate to industrial minerals. This paper will describe the nature and importance of MDA's in Canada and will outline the wide range of activities taking place with respect to industrial minerals.

Jan 1, 1987

By R. E. Gertsch

A mobile-modular carbon adsorption mill design and operation for small to medium sized heap leach precious metal mines is presented. In the mobile-modular strategy, charcoal columns with adsorbed metal move from small strategically located carbon adsorption loading stations to a central stripping facility and back. The design has many advantages: 1) It scales-up from pilot plant to full production. 2) It has low capital requirements. 3) Operational costs are competitive with other systems. 4) Mill production can react quickly to changes in ore grade or property area. 5) The solution circuits are simple and easy to maintain. 6) Charcoal damage is reduced.

Jan 1, 1993

By Feng Liu

"With seven new applications for plans of work for exploration in the international Seabed Area approved by the Council during its twentieth session of the International Seabed Authority, 26 total approvals have been made by the Council up to date. Among them, three contracts were made with COMRA. On 8 August 2014, China Minmetals Corporation submitted another application to the Authority for approval of a plan of work for exploration for polymetallic nodules in the Area, which is also sponsored by the Government of the People’s Republic of China.China is one of the main contributors to the international seabed regime. The Presentation will describe China’s activities in the Area, such as exploration, technology development, environmental protection and policy making.JIAOLONG is a submersible with capacity of 7000 meters. JIAOLONG’s sea trials were carefully made in 4 years, from 2009 through 2012 and it successfully dove to a depth of 7062m in June 2012 at Mariana trench. A so called "Test Application Phase" started thereafter, and is planned to last for 3-4 years. Two cruises and 4 legs have already been made since then. A wide-range of findings were obtained during dives in South China Sea, and in COMRA’s Exploration Contract Areas for polymetallic nodules and cobalt-rich ferromanganese crusts. This presentation will reveal the colorful findings."

Sep 1, 2014

By T. Hayashi

A sophisticated process of extracting ultrafine sulfide mineral particles of under 1µm size suspended in clay slurry has been developed through studies of electrochemical properties of particle surface. Experimental procedure and data of the process applied to some clay ores containing sphalerite and pyrite, and molybdenite and other sulfide minerals are reported. Discussions concentrated on the function of process reagents, particularly on various modifying reagents, and on the effect of dispersed or flocculated state of ultrafine particles in slurry which affect significantly the performance of the process.

Jan 1, 1982

By Raymond Sandiford, Taehyun Moon

"In 2012, Superstorm Sandy (Sandy) caused extensive flooding in many of the tunnels in New York City. The inundation resulted in two distinct stress changes to the tunnel structures. The first stress change was water pressure on the inside face of the tunnel lining. The second condition related to the change in buoyancy of the tunnels. In areas where the tunnels were supported on rock and an adjoining area supported on soft soil, overstress issues arose. Numerical analyses were performed to assess the structural impacts of the tunnel water inundation; especially stress changes due to internal pressure as well as changes resulting from the buoyancy effects. The paper will discuss the assessment process and its results; it will demonstrate that the change in internal pressure were of little consequence, however the change in buoyancy resulted in significant increases in bolt stresses. INTRODUCTION Superstorm Sandy caused tens of billions of dollars in damage in the NYC metropolitan area. It also caused significant disruption to the transportation system by flooding most of the under river tunnels servicing Manhattan from the outer boroughs and New Jersey. The rehabilitation of the tunnels was of paramount importance to the restoration of the NY and NJ economies. With this rapid restoration, it was essential to determine whether the flooding of these tunnels caused damage to tunnel structures. A series of analyses were undertaken to ascertain whether the change in the stress conditions and buoyancy of the tunnels, due to the flooding, was significant enough to cause damage or over-stressing of the tunnel components. The effects of this unforeseen loading condition was a concern to the agencies operating these tunnels and were thus analyzed to ascertain if there were any adverse impacts. This was a concern because the majority of under river tunnels in NYC was built earlier in the century and constructed using bolted cast-iron lining segments. The cast iron, although quite strong in compression, is much less so in tension. Also, after nearly a century of use, the bolts connecting these segments together have under gone varying degrees of corrosion. The stress changes in both the liner segments and the supporting bolts were estimated for conservative ground support conditions to provide confidence that the flooding had not caused permanent damage."

Jan 1, 2016

By P. L. Sibrell

Previous research by the U.S. Bureau of Mines showed that autoclave cyanide leaching of used automobile exhaust catalysts for recovery of platinum group metals (PGM) was technically feasible. This work involves a more detailed investigation of the chemistry of the dissolution of PGM in cyanide solutions. The PGM species in solution identified by ultraviolet spectroscopy. Pt and Pd cyanide complexes were square were The planar in geometry, while the Rh complex was octahedral. The rate of dissolution of the PGM was also investigated using a rotating disk technique. Dissolution rates increased in the order of Rh, pt, and Pd, respectively.

Jan 1, 1994

By D. Elroi

This paper addresses the sharing of 2D and 3D data between GIS and mine planning software. Two-dimensional (2D) data, and now three-dimensional (3D) data as well, can be formatted such that both types of software can use, exchange, and display the same datasets. This increases the ability to share data between such groups as environmental, exploration, and mine planning. It overcomes shortcomings of mine planning software in areas of open database connectivity, spatial analysis, and data input and output. It also helps to overcome shortcomings of GIS software in the areas of geologic modeling, three-dimensional interpolation, and visualization.

Jan 1, 1998

By A. Tew

The Ernest Henry copper-gold project is located in North West Queensland, Australia and commenced production in late August 1997. Utilising a philosophy of selecting the biggest proven equipment available Ernest Henry at full production will treat 9 Mtpa through a single grinding line over a 15 year mine life. 350.000 tonnes of concentrate a year will be produced, containing 95,000 tonnes of copper and 120,000ounces of gold. The two mills recently commissioned at the Ernest Henry Copper/Gold Mine are a 10.4m x 5.1m (34 ft x 16.75 ft) SAG Mill and a 6.1m x 8.4m (20 ft x 27.5 ft) ball mill. The mills have a power draw of 11 MW (14745 hp) and 5.5 MW (7373hp) respectively. While the SAG Mill is not the largest SAG Mill in the world, it is the largest shell-supported SAG Mill in the world. The Ernest Henry mills epitomise the new standard design of large grinding mills. The design was introduced more than 20years ago and has been further developed from extensive experience with grinding mills and the need to produce a design, which overcomes the recognised problems of large mills. The result is a design with the potential to be used for mills up to the largest for which machine tools can be found to fabricate and machine them. currently approximately 15m (48')overall diameter.

Jan 1, 1999

By I. Iwasaki

Precious metals are commonly believed to be recovered along with sulfide minerals in flotation, but a few neutron activation analyses showed that the recoveries of gold and silver were unexpectedly low. Recoveries of platinum group metals remained unresolved due to interferences in the analyses. Electron micro-probe, scanning electron microscope and scanning auger microprobe analyses have identified nickel arsenide minerals in the ore and confirmed a close association of platinum group metals with the arsenide minerals as minute inclusions. These results indicated a need for re-evaluation of flotation procedures which have so far ignored special problems related to arsenide minerals. The electrochemical and flotation behaviors of nickel arsenide and their implications to the flotation recovery of arsenide minerals from copper-nickel bearing Duluth gabbro are presented.

Jan 1, 1985

By George S. Barnett

The Equis and El Roble projects are located in the Cordillera Occidental of Colombia. The Equis vein deposits have sulfide ore reserves of 95.9.5.5 mt (105.770 st) grading 8.51 g/mt (0.248 oz/st) gold and 12.4 g/ml (0.36 oz/st) silver with 0.94 % copper. 1.10 a lead and 11.06% zinc. Ore reserves at El Roble are estimated as 1.1% Mmt (1.21 million st) grading 4.89% copper and 3.39 g/mt (0.099 oz/st) ,old. Geologically possible reserves at Equis may total 1.6.Mmt (1.76 million it). El Roble has the potential to contain several tens of millions of metric tons. Exploration included diamond drilling, trenching, channel sampling, rock and soil geochemistry, geophysics and tunneling. Erratic high grade samples affect the weighting of channel and drill core samples. Secondary reconcentration of gold is also a factor. Sample maps and graphs show the distribution of values to be highly variable. Geostatistical treatment of some of these data gave important guidelines for parameters such as sampling densities, drill hole spacing and confidence limits.

Jan 1, 1984

By Glenn Boyce, Paul Gribbon, Gary Irwin, Greg Colzani, Jim McDonald

This paper discusses the process utilized by the City of Portland Oregon’s Bureau of Environmental Services (BES) to procure and compensate Impregilo-SA Healy (I/H)for the West Side Willamette River Combined Sewer Over?ow (CSO) Project. The contract method is a three-phase process consisting of qualifications based contractor procurement, pre-construction phase design assistance/construction planning, and facility construction where the contractor is compensated on a cost reimbursable-fixed fee basis. The paper focuses on pre-construction phase lessons learned from the development of the contract general conditions, establishment of a construction budget and cost control program, incorporation of contractor recommended design changes, and development of a subcontractor procurement program for construction.

Jan 1, 2003

By Jaime Lomelin

[First of all I want to thank the Society of Mining Engineers of AIME for the opportunity to present what Industrias Penoles, S.A. is doing in Mexico to reach the basic objetive of the enterprise without compromising, in short or long term, the living conditions of the community or attempting in an irreversible form against Nature. Industrias Penoles, S.A. is one of the largest mining and metallurgical companies in Mexico. It was founded in 1887 and at the turn of the century installed a lead smelting operation close to the village of Torreon, which became city five years after the start up of the Penoles smelter. Now Torreon has a population close to 300,000 inhabitants. In 1974 Penoles is still the largest industry in Torreon and the dynamic growth of the city is close related to this factor. Today Penoles in Torreon has a lead smelter with a capacity of 130,000 metric tons/year of bullion, an electrolitic zinc plant of 105,000 metric ton/year, and it is modernizing its lead smelter to control pollution and expand it to 190,000 metric ton/year of bullion including all the services and refinery. The Penoles complex in Torreon is the biggest in the non-ferrous metals field in Latinoamérica.]

Jan 1, 1974

By Paul E. Richardson, Edwin E. Maust

Cyclic voltammetry and surface potential (photovoltage) measurements have been carried out on galena electrodes in sodium tetraborate solutions with added HC1 and NaOH to adjust the pH over the range 2 to 13. The first technique shows that the surface species formed on moderate anodic polarization and reduced on subsequent cathodic polarization are the same over the entire pH range. At anodic potentials, a soluble metal species and excess sulfur are formed; at cathodic potentials, sulfur is reduced to a soluble species. More importantly, excess surface sulfur is formed spontaneously under zero current conditions in alkaline solutions. This has been shown to occur on both polished surfaces and on virgin surfaces produced by in situ cleavage under the electrolyte. The photovoltage gives some insight into the charge and potential distribution at the galena surface. This is found to depend on past electrochemical history and the n- or p-type semiconducting character of the electrode and is interpreted in terms of changes in the surface stoichiometry that occur during reduction or oxidation. The effect of surface stoichiometry on subsequent xanthate interactions is discussed.

Jan 1, 1976

By D. G. Abbott

This paper will describe the development, testing, performance evaluation, and in particular, the utilization for a mining application of revolutionary new mini-disc cutters for use in micro-tunneling and small-and medium-diameter tunneling or mining. It will begin by describing the engineering, testing, and development of rock cutting technology in conjunction with the Rock Boring Laboratories of the Colorado School of Mines. During initial tests, the five-inch cutters were able to penetrate limestone and welded tuff with compressive strengths of 9,000 psi to 24,000 psi. High excavation rates at low thrust and power were achieved with considerably less cutter wear than all previously available conventional discs. Eventually, the discs-with their modified carbide-insert cutting rings, high-load capacity bearings and cantilevered mountings-were able to facilitate the rapid and cost-effective installation of micro-and small-diameter pipes and tunnels in large cobbles and even solid rock, with compressive strengths exceeding 30,000 psi. This paper will also discuss the further development of the machine's cutter head and discs to full-scale site use on a range of tunnel machine sizes and soil conditions, including rock, boulders, and soft ground. Potential mining applications include the installation of tunnels to pro-vide ventilation, emergency escape routes, water drainage, compressed air, electricity, and sand-fill.

Jan 1, 1996

By Ingo Kaundinya

"INTRODUCTION Tunnels are important elements of the German federal road network which have to cope with an increasing traffic load especially of heavy goods vehicles. In order to ensure a high availability and safety level for these key infrastructures, big efforts are required by owners and operators in order to keep all infrastructures up to date. This mainly relates to current European regulations regarding tunnel safety (Directive 2004/54/EG) [1] and their national implementation, which must be fulfilled by many existing tunnels. In this context the German Federal Government spends more than 1.1 billion € for the structural and operational retrofitting of more than 120 existing road tunnels. As many of these projects have recently been finished or are still under progress, experiences and best practices could be reported. After the description of current requirements in national standards regarding structural fire protection, the paper gives an example for an upgrade of a tunnel’s fire protection by installing an additional fire protection system, which is a quite costly measure. Another possibility to fulfill current requirements regarding structural fire protection could be the numerical proof of sufficient bearing capacity of a structure. The influence of different fire loads and fire durations on the bearing capacity of typical road tunnel structures have been investigated in a research project funded by the German Federal Ministry of Transport (BMVI) and coordinated by the Federal Highway Research Institute (BASt). The results of this research project have been used to define a procedure how to investigate existing tunnels regarding structural fire protection. Finally, the research results have also been the basis for a current update of national standards for tunnel construction. REQUIREMENTS REGARDING STRUCTURAL FIRE PROTECTION The structural fire protection design of road tunnels is usually based on temperature-time curves of exposure to fire, for simplicity called ""fire curves"". The fire development after fire growth is illustrated with fire curves. Fire curves can be subdivided into a heating-up phase, a fully developed fire phase, and if applicable, into a cooling-off phase (cf. Figure 1). During the fully developed fire, the fire remains at a certain temperature level."

Jan 1, 2016

By Henry N. Doyle

One can hardly discuss coal pneumoconiosis unless it is placed in the context of the total pneumoconiosis problem in the mining industry. However, it might be well if first we defined a few terms, since it has been my experience that the use of the word pneumoconiosis frequently causes con- fusion among those who are not familiar with the term. Pneumoconiosis comes from two Greek words meaning lung and dust. Hence, the word pneumoconiosis simply means dusty lung, or dust on the lung. There are many forms of the disease, some of which are disabling and some are not. Among the many dusts which cause pneumoconiosis might be included silica, asbestos, coal, talc, iron ore, and many other mineral dusts. Silicosis is a specific form of pneumoconiosis. It is caused by the inhalation of excessive amounts of silicon dioxide in the form of crystalline quartz. The disease is manifested by nodulation of the lungs which is apparent on an X-ray film. Continued exposure to silicon dioxide causes the nodules to grow and ultimately large areas of the lung become scar tissue which pre- vents the lung from performing its physiologic function. In its more advanced stages, there is a significant loss of pulmonary function which accounts for

Jan 1, 1966