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The 21st Annual American Mining Hall of Fame Awards Banquet sponsored by the Mining Foundation of the Southwest will be held at the Sheraton Tucson Hotel in Tucson, AZ on Saturday, Dec. 6, 2003. This year’s inductee, guest of honor and featured speaker at the banquet will be Thomas J. O’Neil, recently retired president and chief operating officer of Cleveland Cliffs Mining. Prior to Cliffs, O’Neil spent 10 years with Cyprus Minerals. He was also professor and head of the Department of Mining and Geological Engineering at the University of Arizona. As representatives of mining heritage, the Hall of Fame will induct James Boyd and Thomas F. Walsh. Walsh discovered a rich gold telluride vein in Ouray, CO, which became the Camp Bird gold mine. Boyd was a former director of the U.S. Bureau of Mines, vice president of Kennecott Copper and later president of Copper Range.

Jan 1, 2003

By P. A. Plunkert, D. E. Morse, L. McCartan, J. F. Papp

The mineral sector is a fundamental part of the U.S. economy. It contributes to the real gross domestic product (GDP) at several stages —basic (mining), intermediate processing, manufacturing of finished goods and construction. The real GDP increased by 3.5 percent from 2004 to 2005. The nominal GDP was $12.5 trillion at the end of 2005. Housing starts were up by more than 5 percent for the year, and the unemployment rate decreased to 5.1 percent in 2005 from 5.5 percent in 2004. The prime interest rate increased from 5.25 percent at the beginning of the year to 7.25 percent at the end of the year. The value of minerals mined in the United States in 2005 rose significantly because of increased unit prices for some metals —particularly molybdenum — and significantly increased production for some industrial minerals, mainly cement, construction sand and gravel, and crushed stone.

Jan 1, 2006

Introduction One hundred years ago, a recent college graduate created the US aluminum industry. He found an economic way to crack the primeval bond that makes the metal so special. Aluminum doesn't "rust" - oxidize progressively. Rather, when exposed to air, it instantly forms a gem-hard but microscopic oxide coating. This seals off oxygen from the metal underneath. Scratch it and the seal reforms instantly. That tight chemical bond is the reason the metal is not found in nature; it exists only as a compound. The bond had to be broken to free the shiny metal. But once it is free, that self-sealing protection, alongside a remarkable strength-to-weight ratio, offers a marvelous material. Until 100 years ago, finding a way to do that economically was a challenge that defied science. Then it was solved, in a remarkable coincidence, on both sides of the Atlantic. And the way was paved for a material that would become the second most widely used metal in the world. Until that time, aluminum was a rare and precious metal. But then two young scientists independently invented the process that took aluminum outside the laboratory and into applications ranging from pots and pans to spacecraft. Discovery of aluminum Other major metals - copper, iron, lead, gold, and silver - had been used for thousands of years. But aluminum was entirely unknown until 1782, when French chemist Antoine Lavoisier suspected its presence. It was not actually discovered until Sir Humphry Davy, in England, detected it in clay in 1807. It was first isolated as a free metal only in 1825, by Denmark's Hans Christian Oersted. For years, laboratory methods yielded aluminum only in tiny amounts costing about $1200/kg ($545 per lb) - $13,333/kg ($6000 per lb) in today's dollars. Methods developed by French scientist Henri Sainte-Claire Deville in 1854 cut the cost to about $200/kg ($90 per lb). King Frederick VII of Denmark had a helmet of aluminum and gold. And Emperor Napoleon III of France reportedly served his most exalted guests at a state dinner with aluminum plates. He left the lower ranks to dine from pure gold. Deville and others continued to reduce production costs. But the price of aluminum still rivaled silver - $31/kg ($14 per lb) versus about $35/kg ($16 per lb) for silver. Then in 1884, a 2.8-kg (6.25-1b), 230-mm-tall (9-in.-tall) aluminum pyramid was cast as the tip of the Washington Monument. It was probably the first architectural use of aluminum. And it is still there after more than a century. The attractive properties of aluminum were obvious: it is lightweight but strong, conducts heat and electricity, reflects light and other electromagnetic radiation, and resists corrosion. But its commercial promise was blocked by its cost. In 1885, the price of aluminum was $17.70/kg ($8 per lb). It stayed there for the next couple of years until the Hall-Heroult process brought it down sharply. Hall-Heroult process lowers aluminum costs The characteristic that kept aluminum hidden so long continued to thwart chemists. Aluminum clings to oxygen so tightly that it is never found as a free metal in nature, and it is hard to break that bond chemically. The best chemical methods of the 1880s required sodium, and sodium itself was expensive. At Oberlin College in Ohio, chemistry professor Frank Fanning Jewett advised his students that anyone who could make aluminum inexpensive would do humanity a favor and get rich as well.

Jan 3, 1987

By Aki Fujii, Hiroshi Dobashi, Mitsuro Matsuda, Yoshinari Kondo

INTRODUCTION The Metropolitan Expressway Central Circular Route with a total length of approximately 47 km is located outside the Inner Circular Route of Tokyo (at a radius of approximately 8 km from the city center). Sections with a length of approximately26 km, slightly less than 60% of the total length, on the east and north sides are in ser-vice. Completing the Central Circular Route (Figure 1) is expected to enable through traffic concentrated at the city center to get around, and to form a well balanced trans-port network, which will alleviate traffic congestion considerably. The Central Circular Shinjuku Route, a section with a length of approximately 11 km on the west side, is now being constructed at a fast pace. The route is being built mainly by the shield tunneling method to carry out work smoothly under a trunk highway carrying heavy traffic and to reduce adverse effects of tunneling work on residents in the neighborhood. Shield tunnels have recently been becoming longer and deeper, and no secondary linings have been used in an increasing number of cases because of the over-crowding of cities or the reduction of budgets for public works. Economical, durable and high-quality segments have been required for linings of shield tunnels. Segments are made of concrete, steel, cast iron or combination thereof. Concrete segments are generally used in shield tunnels of medium to large diameter. Concrete segments are highly durable and resistant to compression, so they are highly resistant to earth pres-sure, water pressure and jack thrust. They are, however, heavy and have low tensile strength, so they are brittle and their corners are likely to spall. Concrete segments should therefore be handled carefully.[1] The authors have developed a steel fiber reinforced highly flowable concrete segment (referred as SFRC segment) that overcomes the weaknesses of concrete segments[2] to construct economical, durable and high-quality linings. SFRC segments have been applied to outbound sections SJ51 through SJ53 of the Central Circular Shinjuku Route. Unlike conventional concrete segments (referred as conventional RC segments), SFRC segments are made of steel fiber reinforced self-compacting highly flowable concrete. SFRC segments require less reinforcing bars than conventional RC segments because steel fibers are expected to work as reinforcements. Steel fiber reinforced concrete is a composite material that overcomes the brittleness of plain concrete, and has higher resistance to bending, tension and shear than

Jan 1, 2007

By F. Habashi

The phosphate fertilizer industry is at present based mainly on the use of sulfuric acid. This technology results in the generation of large amounts of radioactive gypsum that represents disposal and environmental problems. Also it involves the use of expensive reactors for acidification that necessitates the frequent replacing the damaged agitators. Applying hydrometallurgical techniques such as in-situ, heap, or vat leaching to phosphate processing could solve these problems. In this case, however, nitric acid must be used and dicalcium phosphate (40% P2O5) may be obtained as a final product. It is insoluble in water but soluble in citric acid and is an excellent fertilizer. This technology does not interfere with uranium recovery if desired. In addition it permits the recovery of rare earths which are otherwise lost in the gypsum.

Jan 1, 2011

By Leon Maday, Dan L. Pecha, Jeremy Johnson, Daniel N. Adams

The Brightwater conveyance system includes 26 km of tunnels, a 130 mgd pump station, 2 km of micro tunnels, and a 2.4 km outfall. The tunnels extend from Woodinville to Puget Sound through varying soils in 1 to 7 bars of hydrostatic pressure and depths to 185 m. The tunnel diameters range from 4 to 6 m and include numerous lining systems. This paper highlights major shaft and tunnel design, including dual cellshafts, multiple pipe configuration tunnels, polymer concrete segments, and the use of a one pass lining designed to convey high pressure effluent.

Jan 1, 2005

By K. Freytag

The extraction of lignite in open-cast mines has a severe impact on the landscape. Proper landscaping after the shut-down of the mines has always been the statutory responsibility of the mine operator. The large area of the land used for open-cast lignite mining requires special regional planning procedures well in advance of the permitting procedure stipulated in the mining law. The lignite plan determines, among other things, the objectives of land reclamation. These objectives will then be outlined in more detail in the mine operation plans and implemented accordingly. Apart from the actual mining laws and regulations, a large number of environmental laws also determine the process of land reclamation. The success achieved in the field of land reclamation in all mining regions during the recent decades has shown that the lignite mining industry creates new landscapes that do not leave any scars in the countryside and merge very well with it.

Jan 1, 2005

By Chester M. F. Peters

INTRODUCTION There has been considerable discussion in recent years of the strained relations between owners, engineers and contractors caused by the rapid increase in costly litigation in underground excavation due to construction claims. These time consuming claims are not to the best interests of the industry. It has been a conclusion of some of the concerned parties that there could be a substantial reduction in these claims if a mutual respect for each other's roles could be maintained along with a practical contractual arrangement for sharing the risks of the unforeseen costs inherent in the business. This paper will touch on the overall problem of these relationships, but confine the major discussion to the role of geology in claims and, in particular, changed conditions claims, since they form the base for the bulk of those involving geology. Geologists can make a major contribution to the reduction of these claims if their particular abilities are recognized and used properly. CLAIMS AND GEOLOGICAL RISKS The tunnel contractor is strictly bound by the contract he signs, and the risks he assumes thereby must be priced. The most important variable factor on which he must base his price is the geologic data provided and his interpretation of it. If this data does not give a clear picture of the conditions, making it impossible to price

Jan 1, 1974

By T. M. Plouf, G. A. Lang

INTRODUCTION The finding or acquisition of ore bodies containing 200,000 opt gold and greater is becoming more difficult. There are more investors and small heap leach operators who have or can raise the capital to make the investments in the large ore bodies. Echo Bay Mines' approach has been to regionally develop small ore bodies, two or three in the same geographic location, which when considered together contain over 200,000 opt gold. CONCEPT The "world class" ore body syndrome, which many large gold producing companies maintain, can restrict company growth if the finding or acquisition of these large ore bodies is not forthcoming. Another approach has been taken by Echo Bay Mines. The concept is to regionally develop two or three small ore bodies suitable for processing with portable equipment. The systematic scheduling of mining, processing with a single flexible processing plant using the same management/ operator team can reduce your overall investment. The initial selection of mining and crushing equipment suitable for sun11 open pit operations is essential. A very viable option in the mining sequence is to use contract mining/crushing/screening/agglomerating and stacking. This option also lowers your initial capital investment and increases the flexibility in mining as you move from one mining operation to another. LOCATION AND SEQUENCING One single small ore body of itself is not attractive enough for the large producer. The recovery of the initial capital investment, although very rapid, does not make a viable project. The only alternative is to find two or more small ore bodies close enough geographically to each other so that the same management/operator team can be used to run the operations as each is put into operation. Echo Bay Mines has regionally located several ore bodies ranging in recoverable ounces up to 100,000 oz. These small separate ore bodies, located within a 30-mile radius of each other, for planning purposes have been considered as one single ore body. The first small ore body has the initial burden to recover the capital invested in the office, laboratory, power plant and processing plant. Other capital investments such as water supply, access and haul road, fencing, septic system, pads and ponds are reoccurring at each mine site. The first small ore body must recover the initial capital investment in the movable structures as well as the reoccurring capital investment in the fixed structures very rapidly. A total capital recovery time of 6 to 9 months should be used as an economic decision point for both choosing which small ore body should be processed first, and what the plant design capability should be. The sequencing of the small mines is very critical. All the fixed structures mentioned above must be installed at the second mine site before the first mine has been mined out. The ideal sequencing will allow for only one month between shutdown of the first small mine and production from the second. SPECIFIC OPERATION Echo Bay Mines has completed the construction of the Illipah Mine located in White Pine County, Nevada, with this small mine sequence approach. The Illipah Mine is a 40,000 ounce recoverable gold ore body. This ore body met all the necessary requirements. The Illipah project could support the capital investment in the movable structures which will

Jan 1, 1987

By Scott Chesman

Increased TBM performance is leading the way for resurgence in tunneling activity in NYC. Tunnels will be excavated in the same geologic formations as previously excavated D&B tunnels whose construction records are providing valuable insight into the prediction of rock mass behavior. This report compares an eight mile stretch of NYC Water Tunnel #2 with the recently excavated eleven mile stretch of the TBM driven Water Tunnel #3. Comparisons of the type and amount of rock support installed as well as water inflows and grout quantities are made. Rock mass characteristics specific to TBM performance are also evaluated.

Jan 1, 2005

By Vernon K. Garrett, Gerhard Sauer

INTRODUCTION Generations of tunneling engineers had to fight not only against bursting rock and squeezing ground but also against the destroying power of water. Intrusion of groundwater into the tunnel opening affects the stability of the tunnel support system, reduces the safety of the traffic inside the tunnel, induces corrosion of installed equipment, and provides for creeping currents at electric facilities. Aware of these problems, engineers of the Washington Metropolitan Area Transit Authority and their consultants opened the way for a new approach in sealing a tunnel. It was made possible by accepting a new method of tunnel construction scarcely applied in the U.S. before. This new technique, the New Austrian Tunneling Method (NATM), provided the basis for the successful installation of a PVC-membrane between two separated shells of tunnel lining, and the carefully directed drainage of groundwater. Beside of the economic benefits already attained by applying the NATM for tunnel construction, the Authority now saves millions of dollars otherwise necessary to maintain the tunnel during its lifetime (Garrett, 1986; Setzer, 1986). But there is a large number of leaking tunnels built according to conventional methods, some of them facing severe problems jeopardizing the safe utilization of these structures. Recently developed methods indicate that even those tunnels can be rehabilitated without extensive costs by draining and sealing them afterwards. A road tunnel in the Austrian Alps provides the scene for a major attempt to convert one of those leaking tunnels into a dry structure.

Jan 1, 1987

By M. Allan Holtz

The shipment of coal, ores, and minerals in bulk form during the winter months presents a difficult problem in emptying rail cars. U. S. Steel Research in cooperation with U. S. Steel Coal Operations bas laboratory tested and field monitored the effectiveness of using freeze conditioning agents (FCA) to minimize the frozen coal problem. This report examines, in an overview manner, our experience after four seasons of treatment using different FCA agents on raw and preparation plant products. Our observations indicate that if an FCA is applied correctly it is effective mineral to mineral. Freezing problems still occur at the interface between the coal and the metal of the car sides and bottoms. Leading chemical suppliers have made positive improvements in their FCA formulations with second and third generation products. Further advances are needed to make chemical treatment for the prevention of frozen coal a real full-proof method.

Jan 1, 1980

By Edwin F. Shorey, Richard F. Coon, Steven B. Fradkin

Crosstown Interceptor Phase IA is the first deep tunnel element of the Milwaukee Inline Project. The tunnel contract includes 6,492 meters (m) of 9.1-m-diameter tunnel, two access shafts, and partial lining for structural purposes. The work also includes grouting to be performed as directed by the engineer to provide groundwater infiltration control in lined and unlined reaches of the tunnel. This paper summarizes infiltration observations, progress of the grouting work, and its potential application to the remainder of the Milwaukee project.

Jan 1, 1987

By Christine E. Turner-Peterson

Pore-filling organic material concentrated uranium to form sandstone-hosted primary uranium deposits in the Jurassic Morrison Formation of the Grants uranium region, New Mexico. Petrographic observations and radiometric ages for primary ore in the Westwater Canyon Member require that the organic material was emplaced early in the diagenetic history of the host sandstone; in fact, organic material was emplaced before major compaction. This inferred early emplacement constrains models concerning the nature and origin of the organic material and thus also constrains models of ore genesis. Reconstruction of the burial history of the basin indicates that Late Jurassic-Early Cretaceous time, the interval of inferred emplacement of the organic material, was probably not a time of hydrocarbon generation and migration. Nuclear magnetic resonance analyses, elemental abundances, and isotopic studies provide further constraints on the nature of the organic material, and data from these studies are consistent with a humic acid rather than an oil origin. In addition, the overall tabular shape of primary uranium orebodies and the way these orebodies are suspended in the host sandstone mimics Recent deposits of humate, the precipitated form of humic acids. The critical clue that favors a humic acid origin for ore-related organic material is provided by the nature and patterns of postdepositional alterations that are spatially and temporally related to primary ore, specifically destruction of detrital magnetite and ilmenite (iron-titanium oxide) grains. Humic acids are implicated in the destruction of iron-titanium oxide grains because these organic acids are one of the most effective natural agents in leaching of Iron from these grains. Thus, timing constraints, chemical evidence, orebody geometry, and the nature and patterns of ore-related alterations favor a humic acid origin and suggest that an oil origin is highly unlikely. Because alteration of iron-titanium oxide grains tracks the pathways of humic-bearing solutions through the host sandstones, it is possible to trace these solutions back to their source. Alteration patterns in the Westwater Canyon Member suggest that the humic-bearing solutions originated as pore fluids in the mudflat facies of the overlying Brushy Basin Member and moved into adjacent sandstones during early dewatering of the mudstones. The humic acids precipitated, by the process of cation loading, in tabular layers. Uranium was concentrated within these tabular layers by complexation with the humic acids to form primary uranium orebodies.

Jan 1, 2013

By Tuncel M. Yegulalp

This article summarizes some of the results of the continuing research activity at the Henry Krumb School of Mines, Columbia University, directed towards a better understanding of the stochastic behavior of slurry flows in underground coal-slurry pipeline systems. The slurry system under consideration here replaces all conventional haulage systems between the coal face and the coal preparation plant on the surface. At the beginning of the pipeline system, flow rate and frequency of coal slurry is very closely related to the activities of production equipment at the coal face. Due to several scheduled and unscheduled interruptions in continuous miner's coal mining activity, resulting slurry flows possess stochastic characteristics. Proper understanding of these characteristics is believed to lead to a more realissic and economic design of slurry handling equipment. Fundamental ideas supported by field observations are presented and a Semi-Markov model of the slurry flows is developed. As a result of this formulation, behavior of combined slurry flows from N independent coal faces can be expressed in analytical form. The contents of a slurry surge tank receiving slurry flows with certain stochastic characteristics is investigated as a function of discharge pump characteristics and time.

Jan 1, 1981

By C. J. Hall

I would like to congratulate Professor Gershon on an idea that is obviously valuable and is certainly new to me. It has, however, to be further developed, in that one can get fallacious results by limiting oneself to positional weights. In the example problem, the positional weight of one block was 8.6 (the 8.0 value in the paper was incorrect) for 36 units in the cone, for a mean block value of 0.239. The positional weight of the second block was 4.4 for 15 units, for a mean block value of 0.293. Surely one would expect the second block to be rated higher. Additionally, the time value of money adjustment cannot be determined by depth, because the time that a block is mined is determined by the mining sequence, not depth. Figure 1 shows a slightly altered version of Professor Gershon's pit. The overall value of the pit is the same, as are the total values under each of his blocks. The values in the right-hand cone have been reversed top to bottom, and the values in the rest of the pit adjusted to keep the central cone total unchanged. All values have been multiplied by 10. Figure 2 shows the sequence of mining, at three blocks per year, for Professor Gershon's pit, and Fig. 3, the sequence for a pit under the other block. Table 1 shows the value and discounted value (15%) of Professor Gershon's pit, and Table 2 shows similar values for the second pit. It is apparent that the second pit schedule is more valuable than the first.

Jan 1, 1988

By D. Brady

When deciding to deploy rescue teams underground the decision makers need to be able to determine that there won?t be an explosion whilst the rescue teams are underground. Previously general body concentrations in areas likely to be travelled were compared to explosive limits on a one off basis with no formal process looking at trends or other areas. A new approach is being adopted that takes into account the rate of change of gas concentrations with triggers set to enable a withdrawal of personnel prior to a possible explosion and influences such a barometric pressure changes. This paper explains the rationale behind the changes made and the advantages and implications of adopting such an approach.

Jan 1, 2012

By K. W. Grubaugh

Indigenous people are nearly always affected when projects enter their territory. Crop and other asset compensation can help or undermine a project’s progress depending on the approach. When compensation is handled poorly, a technically viable project can get indefinitely entangled by local unrest. Stake holders associated with compensation issues include; the state, the indigenous people, non-governmental organizations, and the developer. Appreciation for the unique perspective of indigenous peoples and the influences affecting them can avert problems and prevent delays. A review of the compensation issues encountered in Ghana during its recent gold boom can assist in avoiding problems associated with handling poor and uneducated people.

Jan 1, 2002

By Faruk Oksuz, Phillip L. Covell, Martin Doll

A series of difficult ground conditions causing high groundwater inflows and hazardous gas intrusion abruptly halted the construction of a 6.4-meter (21-foot) finished diameter and 1,890 meters (6,200 feet) long tunnel planned to serve as a 4-millioncubic meters (1-billion gallon) per day capacity river outfall for treated wastewater. Some 808-meters (2,650-feet) section of the constructed tunnel, TBM, and all other tunneling equipment were completely flooded with hydrogen sulfide laden artesian groundwater. The subsequent pumping and tunnel recovery efforts were unsuccessful and the tunnel was abandoned. In the end, the construction contract was terminated and options to redesign and reconstruct the project were re-evaluated to maximize the use of already constructed tunnel facilities such as the construction access and inter-mediate shafts and six outfall diffuser shafts in the river.

Jan 1, 2007

By William Gleason

"It is safe to say that the coal industry, in the United States and globally, is currently suffering through one of the hardest times in its history.A perfect storm of competition, changing energy demands, politics and public perceptions have collided, inflicting significant harm to the industry that many say is irreparable. This, in turn, has led to massive job losses in some regions, heavy cuts in production and even bankruptcy filings from two of the largest coal mining companies in the nation.Cheaper natural gas can certainly take a large share of the blame for the struggle of coal, as utility companies switch from coal to natural gas for power generation. According to the U.S. Energy Information Administration (EIA) the amount of coal used for electricity generation in the United States is at a 45-year low.November 2015 marked the fifth consecutive month that natural gas was the leading source of power generation in the United States. EIA said generators produced 101,866 thousand megawatt hours (MWh) of electricity with gas in November versus just 87,789 thousand MWh with coal, the lowest monthly level since May 1980 when monthly coal use was 84,884 thousand MWh.According to Robert Godby, director of the Center for Energy Economics and Public Policy at the University of Wyoming, there are a number of factors playing a role in the decline of coal, but he points to the advances in fracking as the tipping point.“A lot of people will argue that regulation is the cause of the decline, and it has played a part, for sure, but the story of the recent past is more about what competition has done to the energy market,” Godby told Mining Engineering. “The war on coal was originally declared by natural gas in 2008.”The price of natural gas, which was at $13 per million Btu before the gas fracking boom, has fallen to as low as $1.68 in December 2015. Likewise, Godby said the cost of wind generation is now lower than the cost of generation from coal and the cost of solar generation is coming down as well. In addition to that, the demand for energy has changed in the past five years with more efficiencies in everything from building design to lightbulbs."

Jan 1, 2015