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By K. Hartman

Certain external forces affect the manner in which business is conducted. and in recent years changes in the business environment have altered how some of these external forces affect the management of a business. These changes must be understood and considered in definition of the strategy of the business. Implementation of the strategy must assure commitment from all departments within a company, and this commitment sometimes involves compromises to assure that a department's goals mesh with the overall business objective such compromises must be externally motivated. i.e. for benefit of the customer. Complete implementation transcends internal departments to all aspects of managing the efforts in the marketplace.

Jan 1, 1989

By Marcel Michaud

Over the past five years, the two-fold growth in Canada's coal industry "Figure, 1" results primarily from the coking coal market to Japan and, to a lesser degree, by the increasing use of sub-bituminous and lignite coal for power generation in the Prairie Provinces. This expansion will continue, but production of coal for domestic thermal generation of electricity will grow at a faster rate than coking coal exports "Figure, 2". Half of the 20 million tons of thermal coal used for electrical power generation in Canada during 1974 were imported by Ontario Hydro from U.S. coal companies in West Virginia and Pennsylvania. Ontario Hydro's Nanticoke station on Lake Erie which will consume 7.5 million tons of coal in 1977 when fully operative, as well as other future planned projects, could cause Ontario Hydro's coal consumption to rise from 10 million tons today to 20 to 25 million tons by 1985

Jan 1, 1975

By James T. Finley

Profit, product quality, speed of operations, reliability, operator confidence, safety and environmental improvements have all been enhanced as a result of the recently completed maintenance, renovation and construction program at Crown Central Petroleum Corporation?s (Crown?s) coke calcining unit at its Pasadena, Texas refinery. (Figure 1) BACKGROUND The calcining unit was built in 1969 - 1970 and has been operated continuously. Approximately 400 to 500 TPD of high quality metallurgical grade coke is manufactured, stored, and shipped to consumers. About 1/2 of the feed stock to the calciner is manufactured in Crown's coking unit and the remainder is received, via barges, from various sources. The green coke is off loaded from the barges with a conventional grab crane that discharges into a small travelling hopper over a conveyor belt that feeds a radial stacker, which forms a stockpile on the ground. The green coke, from the coking unit at the refinery, is moved to the calcining unit with front end loaders. Reclaiming from the stockpiles is also done with front end loaders. The coke is primarily handled by covered conveyor belts. The finished product is stored in steel silos and can be shipped via railroad cars, but the majority of it is shipped out in ocean going bulk carriers. Maintenance work in the calcining unit is performed by Crown's refinery maintenance department on an as needed, on call basis.

Jan 1, 1983

By P. A. Meyer

The Tenmile Range is a north trending zone of high relief within the central Colorado porphyry-mineral belt, located between Leadville and Breckenridge. (Figure 1, the Index Map of the area surveyed.) The Climax mineralized zone is located at the southern end of the range on the northwest side of the Continental Divide. This portion of the total area surveyed will be discussed in detail today. A fixed wing aeromagnetic survey was flown over this range and mineralized zone in the fall of 1957. The survey was run as an experiment to see if a useful geophysical tool could be applied in the exploration for similar type deposits. The purpose of this paper is to describe the results of this survey and the approaches used to aid in the interpretation of the total intensity data.

Jan 1, 1968

By M. D. Carter

The availability of environmentally acceptable and reliable energy sources is an important issue for Federal, State, and local planners. A cooperative program by the U.S. Geological Survey, State geological surveys, and the U.S. Bureau of Mines has developed a national GIS-based systematic effort to collect, analyze, and depict data characterizing the relationship between restrictions to mining and the potential development of the Nation's coal resources. Land use/environmental and technologic/geologic restrictions are identified within selected 1:24,000-scale, 130-to 150-sq-km 7.5-min quadrangles and applied as overlays to maps of coal-bed thickness, depth, and mined-out areas. Tonnages of original, mined and lost-in-mining, remaining, restricted, and available resources are calculated. Resultant data files are transferred to the Bureau of Mines for recoverability and cost analysis.

Jan 1, 1995

By J. R. Patts, L. D. Patts, S. J. Janisko, T. Barone

"Controlling float coal dust in underground coal mines before dispersal into the general airstream can reduce the risk of mine explosions while potentially achieving a more efficient and effective use of rock dust. A prototype, flooded-bed scrubber was evaluated for float coal dust control in the return of a continuous miner section. The scrubber was installed in line between the ventilation tubing and an exhausting auxiliary fan. Airborne and deposited dust mass measurements were collected over a period of three days at set distances from the fan exhaust to assess the changes in float coal dust levels in the return due to the operation of the scrubber. Mass-based measurements were collected on a per-cut basis and were normalized per foot of advance by the continuous miner. Results show that average float coal dust levels measured under baseline conditions were reduced by over 91% when operating the scrubber. INTRODUCTION In 2012, underground mining in the United States produced over 342 million tons of coal [EIA 2013]. During the cutting, crushing, and transport of this coal, dust is generated and can be entrained in the air ventilating the mine. Title 30 Code of Federal Regulations Part 75.400-1 (30 CFR§ 75.400-1) defines float coal dust as particles of coal that can pass a No. 200 sieve. These coal particles can be carried by the ventilating air into return entries before settling onto mine surfaces [NIOSH 2006]. If this float coal dust becomes re-entrained into the airstream, it can propagate an explosion throughout mine workings [Harris et al. 2010]. Application of rock dust in underground coal mines is required by Federal regulation as a means of preventing the propagation of explosions by float coal dust. In order to meet Title 30 Code of Federal Regulations Part 75.403 (30 CFR § 75.403), 80% incombustible content must be maintained in the composition of dust deposited in mine entries [76 Fed. Reg. 35968 (2011)]. This fraction of incombustible content is increased if elevated levels of methane are present. In order to maintain the required incombustible content, frequent or constant application of rock dust is undertaken by mine operators. Title 30 Code of Federal Regulations Part 75.2 (30 CFR § 75.2) defines the properties of the rock dust that must be used by mine operators."

Jan 1, 2015

By Thomas F. Torries

It does not take sophisticated economic analysis to determine the current status of nickel production and demand (Figure 1). One only needs a quick glance at the balance sheets of the major nickel producers to learn that prices are down and profits are supressed to the point where they are major losses. Operations have been closed, and those remaining in production have reduced output. What Is now of interest Is, when will the nickel market improve and to what degree? The purpose of this paper is to attempt to answer these questions. This will be done by the normal method of projecting nickel demand, chosing a production scenario, and analyzing the results.

Jan 1, 1982

By G. Ferrara

Hydrocyclones and other dynamic separators are normally fed with pulps of water and solid particles. The particles have different sizes, shapes and densities and, except in the special case of mono-characteristic particles, are segregated into size, shape and density. Segregation is magnified by the high values of centrifugal acceleration in the hydrocyclones. This paper develops the theory of the segregation, indicates the major variables involved and reports experimental data of segregation under different operating conditions for mixtures of magnetite and/or ferrosilicon and non-magnetic minerals.

Jan 1, 1995

By Ken Wangerud

The benefits of historic mining to this country have been many, but have come at a cost to the environment that has only begun to be understood over the past twenty years. While estimates vary, it is generally recognized that there are over 200,000 inactive and abandoned hardrock mines, with most of them located in the western U.S. Only a fraction of them are believed to be sources of metal releases with significant adverse environmental effects to the watersheds and receiving streams. State water-quality and natural resource management agencies have noted that hundreds of miles of streams are metal-impacted, and the aggregate effects of these sites within watersheds and drainage basins is poorly understood. Resources for the environmental assessment of abandoned mine land (AML) sites and watersheds have been and continue to be limited. Few hardrock mining states receive substantial reclamation funds under the (coal) Surface Mining Control and Reclamation Act. EPA Region VIII (EPA8) has an estimated 90,000 abandoned mining, milling and smelter sites, mainly in Colorado, Montana, South Dakota, Utah and Wyoming. An estimated 13,000 of the sites may have metal releases causing Clean Water Act and CERCLA non-compliance. Results of inventories by states and federal land managing agencies, indicate it is plausible that only 3,000-4,000 of these sites may be causing significant environmental degradation.

Jan 1, 1999

By F. J. Sotillo

Mineral processing requires good classification of particles to attain an adequate separation of minerals. This is of utmost importance in the case of sulfide minerals. An ideal classification is obtained when particles are separated at a given mesh, which is fixed according to the characteristics of each sulfide ore. Under these ideal conditions, particles coarser than the mesh of separation are recovered in the underflow, whereas particles finer than the mesh of separation are recovered in the overflow. This paper presents the results of pilot plant tests that were performed on Ag-Pb-Zn and on Ag-Au Peruvian sulfide ores using a Density Separator, and the comparison of these results with those obtained using hydrocyclones, under similar operating conditions. The results show that the ratio of circulating load is reduced by 50% by using a Density Separator with respect to that obtained by using hydrocyclones. Moreover, the effect of the improvement in the separation efficiency obtained by using the Density Separator on the kinetics of flotation is also shown. Silver recovery of the Ag-Pb-Zn ore increased by 18% whereas gold grade in the concentrate of the Ag-Au ore is doubled.

Jan 1, 1998

By J. W. Scott

The problems involved in installing, maintaining, and operating large vibrating screens have been summarized and discussed, based on a survey of current use of such screens in selected North American mineral processing applications. Practical, effective solutions for the more serious common problems are described, along with some recommendations on design practice for specifying, selecting, and installing large screens.

Jan 1, 1983

By A. L. Crandell

The Cortez Mining District has had a long history of mining activity dating back to 1862 as previously reported (1) (2). More recently Cortez Gold Mines (i) has operated a cyanide leach, counter current decantation (CCD) recovery gold mill from January 1969 to February 1976. This type of plant has been standard in the U.S. for treating higher grade finely disseminated gold in Carlin type ores. The mill was initially operated from 1969 to 1973 at 1520 tonnes per day on oxidized ore from the Cortez ore body. Starting in 1973, the mill was operated at 2050 tonnes per day on softer, less oxidized, high clay ore from Gold Acres which is located 13 kilometers to the west of the Cortez installation. In February of 1976 the oxidized portion of the ore body at Gold Acres was depleted and the mill ceased operation. Successful heap leaching of the lower grade portion of the ores was practiced at both Cortez and Gold Acres to supplement the milling operations. Much valuable experience was gained in the operation of these two heap leaching programs and is well described in an earlier publication (3). Releaching of the ore heaps at Gold Acres and Cortez was continued with a limited crew from 1976 to 1979.

Jan 1, 1986

By D. W. Frommer

Processing nonmagnetic taconites by selective flocculation-desliming and flotation requires large volumes of water. If impounded without treatment these off-process waters require excessively large areas for containment. To discharge the waste water into natural waterways would contribute to stream pollution and likely would not be permitted. In Bureau of Mines experiments conducted in the Twin Cities Metallurgy Research Center&apos;s 900-lb/hr pilot plant, approximately 85 percent of water requirements for the flotation-based treatment of a Michigan nonmagnetic taconite were met by reclaimed water. Water reclamation of the off-process streams from flotation was accomplished by controlled additions of lime, sodium carbonate, and a synthetic flocculant to reduce turbidities to <1,000 ppm equivalent Si02, while maintaining a Ca(II) content of 516 ppm in the finished effluent. Flotation concentrates of good quality were obtained using the reclaimed water. The cost of chemicals used in water reclamation was approximately equal to the savings in flotation reagents attributed to recycling of the water.

Jan 1, 1970

By Peter M. Fozzard

A review is made of the actual costs of recent foreign mineral exploration programmes in third world countries. Target identification leading to the selection of areas, or macro-targets, must follow a well planned and defined series of steps. Suggestions are made with respect to this inter-active project development work. Potential revenues in the broad sense will always determine the overall economics of exploration but clear objective philosophy, good planning and adequate financing are essential for exploration success. Considerable opportunities exist for making important foreign mineral discoveries and broad selected suggestions are made for the identification of exploration areas in relation to high-grade and precious metal mineralization.

Jan 1, 1984

By E. J. Harvey

The Ozarks has been called "a diamond in the rough". In this region streams have steep gradients, sparkling clear flows of cold water fed by many springs, and a wildness that is almost unique in the central part of the United States today. The Current River and its tributary, Jacks Fork, have been set aside for preservation by the National Park Service as a "Wild River" in the first park of its kind in the country. It is called the Ozark National Scenic Riverway. Similarly, responsibility for the preservation of the Eleven Point River has been assigned to the U. S. Forest Service. Protection of other streams in the Ozarks has been considered by State agencies. The hydrologic system of the Ozarks is a complex network of gaining and losing streams, caves, conduits, and large springs. Increased sewage loads derived from the growing towns and expanding tourist trade are a potential hazard; effluents may flow underground for long distances, polluting springs and wells. To add another dimension to the hydrologic picture a new lead industry is also flourishing in the Ozarks. Although the history of lead mining in the area goes back to 1701 (U. S. G. S., p. 43), the area has not seen a revitalization like the one that has been developing in the last 10 years; and the economic growth promises to continue indefinitely. Although this brings capital expenditures and wages into the area, it also brings potential hydrologic problems. Chemicals, wastes and other substances either stored on the surface or transported across it are subject to accidental spillage. In an area where these substances remain on the surface their effects are subject to surveillance. In the Ozarks, however, this may not be possible.

Jan 1, 1970

By Dan Martz, Stuart Lipofsky, Dean Workman

"The Indianapolis Deep Rock Tunnel Connector (DRTC)—first in a vast network of storm water storage tunnels below Indiana, USA—was a wildly successful endeavor. Crews for the Shea/Kiewit JV drove a 6.2 m Robbins Main Beam TBM to world record rates. The machine achieved 124.9 m/day, 515.1 m/week, and 1,754 m/month in limestone and dolomite rock. The advance rates can be attributed to many factors including ground conditions and knowledgeable crew, but continuous conveyors are also of key importance. The novel conveyor system, manufactured by The Robbins Company, enabled continuous tunneling in a difficult layout that included two 90-degree curves and two S-curves. Spanning 11,777 m in its longest iteration, the system included nine booster drives plus a main drive. A vertical belt moved muck up the 76 m deep shaft to a radial stacker for temporary storage. The system, one of the most complex in North America and the first to operate in 90-degree curves, made swift tunneling possible. This paper will examine the world-class tunneling done at the Indianapolis DRTC and the role of continuous conveyance in reaching high advance rates. The logistics of the system will also be examined as it could apply to future tunneling projects with similarly complex layouts. INTRODUCTION The Indianapolis Deep Rock Tunnel Connector (DRTC) is the first phase of a nearly 28-mile long network of deep rock tunnels being built 76 m beneath the City of Indianapolis, Indiana by Citizens Energy Group. The Deep Rock Tunnel Connector (DRTC) Project is a 12.2 km, 5.5 m diameter tunnel constructed by S-K JV, a joint venture between J.F. Shea Construction and Kiewit Infrastructure Co. The tunnel is a $179 million project and is the first segment and southernmost portion of a deep, large diameter conveyance and storage tunnel system to provide overflow relief during wet weather events. The project is estimated to be completed in 2017 and will initially deliver 204,000 cubic meters of the planned 1 million cubic meters of CSO storage for treatment, as well as provide future connections to other tunnels in the overall system (see Figure 1)."

Jan 1, 2016

By William J. Halvorsen

We are currently doing work on three ways to improve the performance of our froth flotation systems. One development is the use of a cationic flocculent added to the feed of the froth cells. This does give some improvement in ash of the product particularly in a situation where there is a good bit of clay present. Difficulty is usually experienced with clay carrying over with the water contained in the froth product and also adhering to the coal surfaces. Addition of the flocculent to the flotation feed preferentially flocculates the clay causing it to drop into the tails. The results of some laboratory test work on Pittsburgh 88 Seam coal in Eastern Ohio is shown in Table 1. [ ]

Jan 1, 1979

By R. H. Weiland

The dewatering of flocculated clay suspensions by compression in a centrifugal field has been investigated. The results are evaluated with regard to both direct applicability to centrifugal dewatering, in solid-bowl centrifuges for example, and indirect applications to gravity sedimentation systems. It is well known that sediment consolidation under gravity depends on structural characteristics such as permeability and on the "self-weight" of overlying sediment layers. An important objective of the study has been to evaluate the self-weight effect using centrifugal forces to simulate consolidation in deep sediments. In this way, small-scale laboratory tests can be used to predict the rates and limits of sediment compression in industrial systems such as thickeners and settling ponds. Experiments have been conducted in which the sediment mass and initial structure were maintained constant while the effective sediment weight was varied by centrifuging at different speeds. The effects of initial structure have also been studied using controlled variations in flocculation conditions.

Jan 1, 1993

By J. DeYoung

Weak demand for metals and consequent low metal prices resulted in continuation of the depressed state of US mineral exploration activity through 1983. Data collected by Resources for the Future Inc. and The Pennsylvania State University for a cooperative study on mineral exploration activity indicate that US exploration in 1983 fell by as much as 25% from 1982 levels. Precious metals remained the focus of most exploration efforts, as gold and silver prices remained attractive compared to base metals. Reports of 1983 domestic exploration and development activities in several industry journals indicates that about 85% to 90% of those projects were directed primarily at gold and silver. Gold exploration included work by several companies on Carlin- type disseminated gold deposits in Nevada, geological prospecting and drilling in the Wenatchee Gold Belt in Washington, and interest in lode and placer gold properties in California, especially by several small Canadian firms. Precious metals exploration projects were also reported in Alaska, Arizona, Colorado, Montana, New Mexico, Oregon, South Dakota, and Utah. There was also tome precious metal exploration activity in the eastern US. Development continued at the Ropes gold mine near Ishpeming, MI, and companies explored historic gold-producing areas in the Southeast. Some exploration for nonprecious metals took place last year. Stratabound copper-silver deposits were examined in western Montana, and US Borax continued exploring molybdenum resources in the Misty Fjords area in Alaska. Work on these projects during 1983 may have been stimulated by time limits on the availability of certain federal lands for exploration more than by projected improvements in metal markets. During 1983, several papers were published on mineral exploration strategies and the future of US exploration. David Watson of Raymond Kaiser Engineers, in a paper presented at the 1983 AMC Mining Convention, forecast increased exploration activity for gold and silver because of world economic conditions. He added that antimony, manganese, chromium, graphite, mercury, tantalum, tin, and barite are also likely targets based on their limited domestic reserve availability. He cited concern over reported subsidized mineral production by foreign producers and US regulatory and land-planning policies as retarding mineral exploration activity. Douglas Cook of Freeport Exploration Co., at the same meeting, presented a paper that showed that a 1950-75 period of vigorous exploration has been followed by a period where acquisition has replaced exploration as the predominant means of acquiring new mineral properties. At a December IIASA conference on "The Economics of Mineral Exploration," in Vienna, Austria, A. Rose and R. Eggert of The Pennsylvania State University pointed out that recent exploration decisions tend to rely more on evaluating production costs and comparing them with existing deposits, rather than on return of

Jan 5, 1984

By James P. Odendahl

Missouri is a state rich in mineral commodities. There is a variety of types of mining as well as minerals in the state. Different phases of mining are controlled by a variety of state and federal laws. What I hope to do today is to present briefly some of the interaction and interplay that has occurred in the recent years between the mineral industry and the Missouri regulatory agencies, as well as some of the interactions by federal agencies. First a little history which dates back to the late 1600&apos;s. For many years Missouri has been a leader in the production of lead and zinc. In fact, recent studies have indicated that Missouri produces better than three-fourths of the nation&apos;s present lead supply. Less well known but important resource is iron mining. Some of these operations were the source of confrontation during the Civil War. Major battles were fought in and around Ironton, Missouri where iron mining has occurred for many years. One of the largest pelletizing operations in the state is currently located within the city of Ironton. Joplin, Missouri, the home of Thomas Hart Benton, the famous Missouri painter, has a history of lead and zinc mining, going back to the later 1800&apos;s. Many of the paintings by Benton contain reference to the early days of mining in Missouri. There is a Benton mural in the City Hall at Carthage depicting the early days of lead mining in that area. Later, the center of lead mining moved to southeast Missouri near Bonne Terre and Flat River. The names of the towns in this area reflect the history of mining, examples - Leadington, Old Mines, Rivermines, etc. The history of lead mining in Missouri has been referred to in some detail in various publications(l).

Jan 1, 1977