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By W. N. Patterson

The three major objectives of this contract were (1) to survey underground diesel-powered mining machinery to determine noise exposure problems, (2) to recommend noise control techniques, and (3) to develop a technique for predicting underground sound levels from surface sound power measurements. The objectives were achieved. The contractor developed information on the severity of the noise problem caused by diesel engines underground and pinpointed the equipment causing the problems. He recommended a number of corrective techniques that can provide relief until long-term solutions are found. A procedure for predicting underground noise levels from above-ground measurements of the machine noise was found valid for several cases tested.

Jan 1, 1975

By John Wilson

This report describes the performance of Phase I of a project to design, analyze, and demonstrate a multilift longwall mining method applicable to mining coal seams twelve (12) feet or more in thickness. A non-simultaneous multilift operation is the most viable thick seam mining technique for introduction to the United States coal industry. In the case of the proposed site at Emery, Utah it will result in an increase in coal extraction from 30% with present methods to at least 50% and possibly more. The major technological advance involved in this project is mining a lower lift under a previously mined upper lift. To accomplish this, entries must be developed and maintained beneath the upper lift gob. This will necessitate the use of steel supports at frequent intervals throughout the lower lift' entry system. This has not been done in the U.S. to date. An economic analysis of the project indicates that, while this method will result in a higher than average cost per ton for coal mined, the coal would be competitive with current-operation in the area.

Jan 1, 1976

By Michael K. O’Leary, William D. Coplin

"Risks from political instability and government policies restricting equity ownership, local operations and transfers of payments affect the profitability of foreign mining ventures. More than seat-of-the-pants judgments and old-boy networks are required to anticipate these risks and to take actions appropriate to offsetting them. A system for making political forecasts, called the Prince System, and a series of charts relaying risk s to a production of key minerals will be presented.IntroductionFirm s with extractive operations outside their home country do not have to be told that political stability and government decisions play a big role in the success o f their operations. The takeover of copper firm s in Chile during the Allende administration in 1971 and the recent decision by Venezuela to reduce Reynolds Metals equity share in a smelting operation from 50% to 28% are two examples of hundreds of events that have determined the profitability of extractive operations over the past decade. Both risks and opportunities for international firms seeking to produce and market raw materials are heavily affected by political conditions. While news of political events travel much faster than in the past and host governments are more clever in shaping the risks as well as the opportunities, politics has always been part of the mining business.What has changed is the need to be more systematic in approaching the assessment of political conditions and how it affects business. The increasing costs of extractive operations, the need for long-range planning, the importance of financial arrangements and the world-wide scope of man y firm s' activities require that the assessment be updated continuously and be comparable across different countries and different types of investments. Political risk analysis, the assessment o f macro-political changes and specific governmental decision s on the operations of extractive industries needs to become as systematic and integrated into corporate decision -making as economic analysis has become over the past two decade s."

Jan 1, 1983

By Zay Jeffries

Tungsten has the highest melting point of all the known metals, namely 3350 C.; it is one of the hardest of the metals; it has the highest equiaxing or recrystallization temperature after strain hardening, of any pure metal known. It is particularly distinguished because, when composed of small equiaxed grains, it is extremely brittle and fragile at room temperature, and when possessing a fibrous structure it may be ductile and pliable at room temperature. The common ductile metals act in exactly the opposite manner in this respect. The present paper will include a brief note regarding the manufacture of wrought and ductile tungsten. The metallography of wrought and ductile tungsten in the various stages of manufacture will be considered more or less in detail. The general relationships between the properties of tungsten and other metals will also be considered. A discussion will be given explaining why fibrous tungsten is ductile at room temperature, even though past experience with other metals would indicate that it should be brittle. Finally, a brief note regarding some new fundamental metallographic propositions relating to all metals will be given. Manufacture of Wrought and Ductile Tungsten Up to about 10 years ago, it had not been possible to work tungsten mechanically. About the year 1908, Dr. William D. Coolidge, of the General Electrie Go., produced ductile tungsten from what was then supposed to be an inherently brittle metal and which, in fact, was inherently brittle in its normal state, that is, when composed of equiaxed grains. Since that time many products, chief among which are the filaments for electric incandescent lamps, have been made from wrought and ductile tungsten. Tungsten is produced chiefly from the minerals wolframite and scheelite.1-8 The ores may be reduced in many ways. For example, the ore may be fused with alkali carbonates and the fusion dissolved in water; sodium tungstate is formed, which is soluble in water. This

Jan 1, 1919

By F. C. Kelley, L. L. Wyman

In order to clarify and amplify the existing data concerning the action of the cementing material in cemented tungsten carbide alloys, the authors have initiated this investigation of the entire range of cobalt-tungsten carbide alloys. Inasmuch as the ultimate objective is relative to what actually goes on during the sintering of cemented tungsten carbide materials, this work was necessarily restricted to heat treatments similar to those used in actual production of these materials. In the course of numerous experiments, the authors have noted several conditions that indicated that there was a solubility to be considered. Among these factors are the following: 1. Many of the alloys showed a much larger amount of binding constituent to be present than could possibly be accounted for by the cobalt content. 2. In many areas, grains of the carbide constituent are much larger than the particles of carbide originally added. In addition, these grains are of very regular contour. 2a. In samples of cemented tungsten carbide which had been fused in the atomic hydrogen torch in the presence of excess binder constituent, immense grains are formed, and their shapes are very regular. This is also true when the cemented tungsten carbide of 13 per cent. Co content is fused alone in the atomic hydrogen torch. Contrary to general expectation, chemical analysis of this material, after fusion in the atomic hydrogen torch, checks the analysis of unfused material. 3. In making the cemented tungsten carbide materials by the process of exerting the pressure at the time of heating a certain portion of the ' contents squeezed out of the mold. Chemical analysis has shown that this material contains approximately 12 to 20 per cent. of tungsten. The microstructure shows a cored dendritic structure interlaced with eutectic network, and some graphite, as shown in Fig. 1. 4. Thermal analysis of these materials has consistently indicated an arrest point close to 1350" C.

Jan 1, 1931

By W. L. Martin, J. N. Dew, H. B. Steves, M. L. Powers

This paper presents and discusses the results obtained during a pilot test in the Loco field in southern Okla homa. The test was conducted in a 2%-acre pattern that was part of a 20-acre conventional waterflood pilot area. The conventional flood was well past its economic limit when the hot waterflood was initiated to obtain technical information and operating experience. Temperature data from nine observation wells showed that about 75 percent of the pattern was affected by heat, and that heat losses were severe in the pilot pattern. About 60 percent of the injected heat was lost to overburden and underburden zones during hot-water injection. Wellbore heat losses were held at tolerable levels at the shallow depth of the test by providing a low-pressure air annulus between the injection tubing and well casing. Hot water provided water injectivity increases of 200 to 400 percent. The hot water channeled across the lower portion of the oil sand in three directions through zones of relatively high water saturation. There was no conclusive evidence that natural fractures or pressure partings aflected the flow of fluids in the pilot pattern; however response undoubtedly was aflected by localized pressure gradients and by injection-production rate ratios. The results showed that hot waterflooding increased oil recovery in a reservoir containing 600 cp oil. The total tertiary oil production from the pilot pattern area was 3,896 bbl or about 156 bbl/acre-ft swept by heat. The corre.sponding WOR was about 34:I. Description of the Hot Waterflood Process To hot waterflood an oil reservoir, water is injected that has been heated to a temperature substantially higher than the original reservoir temperature, but lower than the vaporization temperature of water at the prevailing pressures. In the reservoir the hot water flows continuously into cooler sand and rapidly loses heat to the sand until it has been cooled to the original reservoir temperature. Thus, a heated zone and a region or "bank" of cooled water begins to accumulate immediately after hot water injection is started. This bank of cooled water continues to grow ahead of the heated zone, which also grows, but at a slower rate. This occurs because heat transfer is almost instantaneous, and the ratio of heat capacities of water to rock is such that two or three unit PV of hot water must be injected to heat a given unit bulk volume of the reservoir. The primary displacement mechanism is the same for both hot and conventional cold waterfloods; i.e., "piston" displacement occurs at the original reservoir temperature. The incremental benefits of hot waterflooding usually occur long after the breakthrough of cold water at producing wells, and the increased oil recovery necessarily is accomplished with high WOR's (water-oil ratios). Heat decreases the viscosity and density of oil and water. These effects result in more rapid and increased recovery of secondary or tertiary oil. If the cost of the required heat is low enough, the ultimate oil recovery of a hot waterflood should be increased substantially over what would be expected at the economic limit of a conventional cold waterflood. The economic benefits of any hot-fluid injection project depend primarily upon the cost of the heat required to produce more oil at an increased rate. This cost depends in part upon the amount of heat lost to surrounding formations. Heat loss depends upon reservoir thickness, water injection rate and temperature, the depth of the formation, well spacing, and the characteristics of the reservoir rock and surrounding formations. In general, percentage heat losses decrease as injection rate and reservoir thickness increase. Although it is an old idea, hot-water injection has not received widespread field application in the oil industry as a drive process. Much of the original field work with hot water was done in Pennsylvania fields where water permeabilities and injection rates are low. In these cases, hot-water injection was used primarily as a means of increasing in-jectivities — not as a recovery process. Ramey' recently has published an excellent review of the development of hot fluid injection processes. Recent publications"' and our own experiences now indicate that hot water or steam injection also can effectively increase the oil recovery from reservoirs containing viscous crudes. However, the economics of these methods as displacement processes have not been established. Several theoretical predictive techniques have been published (for a review see Ramey'), but simplifying assumptions make

Jan 1, 1969

By G. Stuart Littlejohn

In spite of recent concerns in certain European countries, I believe that silicate-ester grouts will continue to be employed in practice, unless more cost-effective inorganic grouts are developed for the treatment of fine sands. It is also noteworthy that over the past 40 years, there has been a record of good experience where silicate-ester grouts have been used in ground improvement. Nevertheless, there is now a need via the European Standard EN 12715 (2000) "to assess the environmental impact, particularly the toxicity of the grout and grout components, and their effect on ground and drinking water should be considered before grouting." "When testing the grouting material for environmental impact, the following aspects should be considered: ? Whether during processing, transport or grouting, substance can be generated or released which could be hazardous to the environment or the grouting crew; ? Whether noxious substances can spread upon mixing with ground water; ? Whether reaction products can be produced or released which influence the water quality; ? The type of particles eroded from hardened grout; ? Chemical reactions between hardened grout and the ground water."

Feb 10, 2003

By D. C. White

The Vulture Mine near Wickenburg, Arizona was a major gold producer from 1863 to 1942, having yielded about 11,000 kg Au and 8,000 kg Ag. Gold occurs as coarse native metal and electrum in quartz veins and also finely disseminated within a quartz monzonite sill and its silicified wall rock. The sill is semi-conformable within a Proterozoic volcaniclastic-dominated sequence all dipping north about 35°. Early mining focused on the vein-hosted gold particularly in the immediate hanging wall and footwall of the sill. Later efforts included some open-pitting of the outcropping sill and adjacent altered and mineralized rock. Two sets of post-mineral faults have complicated the orebody geometry.

Jan 1, 1988

Jan 1, 1947

By M. Wason

An Ore bed magnetic liner element is made of permanent ceramic magnets embedded in a rubber molding. (See figure 1) They are difficult and expensive to manufacture correctly. Therefore, the lining for a complete mill is expensive, as high as 400% more than conventional rubber liners. The magnets are not very resistant to impact as they are very brittle. Mills of 12 feet or more can use only I inch balls; mills under 12 feet can use balls of 1-1/2 inches. These liners are therefore used in regrind applications with small balls or in secondary pebble mills. Rubber liners for these applications last a long time, so if life was the only consideration, the pay back for these liners would be longer than the life of the mine. The Ore bed liner and its bed of ball chips or magnetic ore is relatively thin and the surface of this bed has a high coefficient of friction. The liners are made so that opposing poles are situated next to each other and that the mill shell and the bed of ore or ball chips completes the magnetic circuit. (See figure 2) The combinations of these properties results in a very efficient liner. Due to the low profile of this bed, there is no material that is lifted too high, so we have a very compact charge with very high attrition, good for fine grinding. These liners have shown a 10% ball consumption reduction and a 10% lower power draw for the same capacity. Due to the magnetic orientation, the bed is formed in a wave shape along the lines of magnetic force. Tests conducted at a copper mine in the southwest United States have confirmed these findings. The mills where the liners were tested are 10.5 feet by 16 feet Hardinge regrind mills operating as overflow ball mills.

Jan 1, 1999

By William Reisz

In our line of work,like many other professions, there may be times when circumstances or a series of events may arise, contributing toward unacceptable risk. When multiple parties are involved, there will almost inevitably be differences on how best to deal with these situations. Unless approached in an intelligent and these differences may often have the potential for costly and unexpected results.

Jan 1, 2014

Operationalizing the Ruggie Framework in a Mining Context Ruggie?s 3 Pillars: The State?s duty to Protect Policies, regulation, adjudication The Corporation?s responsibility to respect Acting with due diligence to avoid infringing Addressing adverse impacts when involved in abuses Access to Remedy ??even the most concerted efforts cannot prevent all abuse.?

May 1, 2013

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

?Four-wheel, skid-steer, rover developed for CSA ?U-chassis for payload accommodation ?Passive geometric suspension ?Max speed 13km/hr ?Remote workstation ?275kg payload capacity ?On-board processor, IMU, motor encoders ?5.2kW-h battery capacity

May 1, 2013

By Anthony T. Eyton

Intelligent Systems: Advantages for Mining ? Increased safety (reduced risk to workers) ? Increased productivity (reduced downtime) ? Reduced maintenance costs ? Customized solutions for different mines ? Growing acceptance among mine managers A Typical Precarn Project ? Meets definition of intelligent systems ? Involves at least two Precarn members ? a technology developer partner and a user partner ? in a true collaboration ? Involves at least one university and may have various other players ? Leads to a demonstrated prototype ? Costs $2-4 million, and lasts 12-30 months ? Gets up to 40% of its funding from Precarn (max. $1 m) ? Produces new intellectual property -- owned by the project team

May 1, 2002

By Shane Yanagisawa

The Mineral Creek Diversion Project is at the Asarco Ray Mine Complex, about128 km (80 miles) east of Phoenix, Arizona. The new tunnel will intercept the waters of Mineral Creek about 2,134 m (7,000 ft) upstream from an existing tunnel. The 5.74 m(18.83 ft) hard rock TBM will break into the old tunnel about 2,162 m (7,090 ft) in from the old portal after mining 3,888 m (12,753 ft). The TBM will mine through a series of igneous and metamorphic formations including volcanic tuff, soft volcanic ash, massive diabase, fractured quartzite, and schist. The TBM will hole through into the existing 4.88 m (16 ft) dia. horseshoe tunnel where the TBM will be disassembled and removed from the tunnel.

Jan 1, 2001

By A. M. Laird

Endako Mines' molybdenum operation is located near the geographic center of the province of British Columbia, Canada. The property is six miles south of the Northern Transprovincial Highway and the northern main line of the Canadian National Railway. The area is broken by high hills covered with dense stands of spruce and pine with vast areas of the valley floors covered with aspen and poplar. The climate is moderate with precipitation averaging 22 inches per year. Approximately four feet of snow accumulates in the winter, and temperatures range from 900 F. in summer to -40° F. in winter. The orebody, a lowgrade porphyry type deposit, occurs in a widespread granitic intrusive which has been locally weakened at the intersection of two regional faults. In this vicinity the quartz monzonite has been further shattered to permit the entry of mineralizing solutions and local dykes. Two types of mineralization occur within the orebody. The most prom¬inent is the six inch to four foot wide continuous quartz veins with characteristic ribbons of molybdenite and frequently finely-divided grains of molybdenite within the quartz. The second type occurs as fine fractures filled with quartz molybdenite in the form of a stockwork halo radiating out from 20 to 200 feet from the quartz veins. Minor hematite, magnetite and chalcopyrite are also present. Mineralization is roughly proportional to the extent of kaolinization in the quartz monzonite, kaolinization being one of three distinct forms of hydrothermal alteration. Pyrite is commonly associated with molybdenum mineralization within the orebody and a pyrite halo is recognized on the south side of the orebody.

Jan 1, 1968

By S. A. J. Hopper

"The Golden Manitou mine is in the northeast quarter of Bourlamaque township, Abitibi county, Quebec. During the summer of 1937 a body of gold-silver-zinc ore was outlined in a series of diamond drill holes located to the west of an old copper-zinc showing in the property of Quebec Manitou Mines, Limited. In 1938, a shaft was sunk and the orebody further explored from levels at depths of 210 and 360 feet.In 1941 the western half of the Quebec Manitou property was acquired by a new company, Golden Manitou Mines, Limited, and the installation of a mining and milling plant was at once undertaken. Milling started in August 1942. The following is a summary of production to December 31, 1946:The orebodies are sulphide replacements in a sericite schist shear zone. They vary in width from 8 feet to 65 feet and range in length up to 850 feet . Much of the ore is of the 'massive sulphides' type . The sulphide minerals in the ore are pyrite and sphalerite with minor quantities of .galena, tennantite, chalcopyrite, and arsenopyrite. Native silver (as wire and leaf silver) has been found in vugs and as coatings along fractures. In one section of the mine a few specks of gold were observed. Spectrographic analysis of ore samples has indicated the presence of zinc silicate."

Jan 1, 1954

By Sterling S. Cook

The U.S. Bureau of Mines is conducting core leaching experiments with sulfuric acid on oxide copper ores from the Cyprus Casa Grande and ASARCO Santa Cruz deposits in Arizona to further our understanding of the leaching process in supergene copper ores as it relates to in situ mining. Leach solutions from atacamite mineralization contained 5 to 30 g/l copper and few extraneous ions. Leachant from chrysocolla ores, with grades similar to the atacamite, contained 2 to 9 g/l copper and abundant extraneous ions. Quartz and K-feldspar had no impact on leach solution composition at any acid concentration (up to 40 g/l) while illite and sericite had minimal impact. Biotite, calcium-rich clay and limonite have a significant impact on solution chemistry when there is abundant free acid in solution. High acid concentrations increase acid consumption in ores with abundant biotite and limonite gangue. High acid concentrations can be used in ores with quartz, K-feldspar, and sericite gangues without increasing acid consumption per unit of copper removed.

Jan 1, 1988

By AIME AIME

THE Petroleum Division will hold two meetings this fall, one on the Coast at Los Angeles, Sept. 29, with the technical sessions in the assembly room of the California Oil and Gas Association and a banquet Friday evening at the Richfield Cafe atop the Richfield building; the other in the Southwest, at Dallas, Texas, Oct. 6 and 7, with the Baker Hotel as headquarters. Dr. Frederick M. Becket, President of the Institute, and A. B. Parsons, Secretary, will attend both meetings. Arrangements for the meetings are not yet complete but the respective local committees, working in close touch with the officials of the Division are rapidly shaping up the programs and other detail.

Jan 1, 1933