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By Charles W. Daugherty, Robert Nyren

The replacement of Boston’s elevated Highway I-93 running north to south through the heart of the city with 8-lane tunneled roadways, coupled with the underground extension of Highway I-90 eastward to Logan Airport, has earned the Central Artery/Tunnel (CA/T) Project the position of the largest infrastructure project in the U.S. today. The gigantic interchange featuring numerous ramps where these two main branches of the Artery intersect required the construction of three huge jacked tunnel boxes that were pushed beneath eight active Amtrak and commuter rail tracks that had to remain undisturbed in spite of poor geology and a minimum of cover between the track beds and the tunnel crowns. Ground freezing was chosen as the method of stabilizing the soil over the tunnels, and it was extended in one area to stabilize the ground at the intersection between the tunnels and an abutting deep cut-and-cover excavation. Because many standard geotechnical instruments consist basically of open standpipes filled with water, it was a major challenge to keep them de-iced and in a condition to provide data on vertical and lateral ground movements. The efforts to do so are herein described.

Jan 1, 2003

By Ray E. Harris

A resource of 134,400,000,000 tons of minable trona and mixed trona and halite underlies an area of about 1,300 square miles vest of Green River, Wyoming (Culbertson, in preparation)(Figure 1). In 1982, the total domestic consumption of soda ash (refined trona) was 6,667,000 short tons (Kostick, 1983), approximately 90 percent of which came from Wyoming trona. This enormous resource occurs in the Wilkins Peak Member of the Creen River Formation (Eocene). The Green River Formation is derived from sediments deposited in a large lake (Lake Gosiute) that occupied the Green River Basin in south-western Wyoming 38-54 million years ago. The Wilkins Peak Member represents a restricted, evaporite-rich cycle of deposition during which time the trona deposits were formed. A total of 42 trona beds are known, of which 25 are of sufficient thickness and extent to be considered minable (Culbertson, in preparation).

Jan 1, 1984

By T. O. Kuhl

The Royal-Mountain King Project is 7.2 kilometers (4.5 miles) northwest of Copperopolis, California. Reserves of 8,250,000 t (9,100,000 st) at 2.32 g/t (0.068 oz/st) gold will be processed at 2500 t/d (2750 st/d) from three pits. Production is scheduled to begin the first quarter of 1989. District geology consists of northwest trending sequences of Jurassic meta-sedimentary and meta-volcanic rocks. Three ore bodies are located along the Hodson fault which trends northwest and dips 40 degrees northeast. The Gold Knoll and North Pit ore bodies are hosted in carbonate and silica altered meta-volcanic rocks whereas the Skyrocket ore body is hosted in quartz stockwork zones in meta-sedimentary rocks. Gold is present as inclusions and micro-veinlets in pyrite.

Jan 1, 1989

By K. L. Bickel

Catalyzed diesel particulate filters (CDPFs) are used for reducing diesel particulate matter (DPM) concentrations in underground mines. The U.S. Bureau of Mines is conducting research on how catalyzed diesel particulate filters perform. Two CDPFs, with two different catalysts, are used on vehicles in two mines. The CDPFs are periodically removed from service and evaluated in the laboratory to determine their DPM collection efficiency, regeneration temperature, and effects on gaseous hydrocarbon (HC) and carbon monoxide (CO) emissions. This report summarizes the results of the laboratory evaluation, and the mines' experience with the CDPFs. Both CDPFs have operated over 2,000 h. One was evaluated after 1,646 h; its collection efficiency at one operating condition was 87.3 pct. After 2,135 h of operation it was removed from service because it was damaged. The second CDPF continues to be used after 2,328 h of service. The laboratory evaluation indicated its collection efficiency decreased after 1,584 h of use and its regeneration temperature increased from 405' C to 420' C. The mines' experiences with the two CDPFs varied. While being used on mine vehicles, both CDPFs became plugged with DPM on a number of occasions because of insufficient regeneration. CDPFs are capable of lowering DPM concentrations in diesel exhaust. They can also lower emissions of CO and HC, depending on the type of catalyst used. In this study, the performance of the CDPFs changed with use. Recommendations are given in this report for proper use of CDPFs in mines.

Jan 1, 1994

By D. W. Fuerstenau, P. C. Kapur

A model equation is presented for breakage of single particles as a function of the impact energy. The model takes explicit cognizance of the distribution of feed particles in their resistance to breakage as well as of the weakening of particles under repeated impacts. With the proposed formulation, it is possible to simulate the size spectra of progeny particles, interrelate quantitatively the so-called ‘t’ family of curves, derive an energy-size reduction relationship, compute the primary, energy-free breakage distribution function, and predict the optimum level of impact energy for a given size reduction task. Published data on single-particle impact grinding are in agreement with the model.

Jan 1, 1995

By S. S. Hsieh

The important carboxylic acid components of tall oils were tested individually as phosphate flotation reagents. These included C18 unsaturated fatty acids and C10 to C18 saturated fatty acids and resin acids. These experiments were conducted to evaluate such factors as the degree of unsaturation, hydrocarbon chain length, isomeric form, side-group modification, and cyclic structure. The effects of mineralogical characteristics on flotation response also were considered. The results of this systematic evaluation provide guidelines for selecting efficient substitute reagents and also provide fundamental data for further research on improved flotation technology.

Jan 1, 1980

By G. Frey, D. Scott, C. Pritchard

Controlled recirculation has been used in the metal/nonmetal mining industry for energy savings when heating and cooling air, in undersea mining and for increasing airflow to mining areas. For safe and effective use of controlled district recirculation, adequate airflow to dilute contaminants must exist prior to implementation, ventilation circuit parameters must be accurately quantified, ventilation network modeling must be up to date, emergency planning scenarios must be performed and effective monitoring and control systems must be installed and used. Safety and health issues that must be considered and may be improved through the use of controlled district recirculation include blasting fumes, dust, diesel emissions, radon and contaminants from mine fires. Controlled recirculation methods are expected to become more widely used as mines reach greater working depths, requiring that these health and safety issues be well understood. The U.S. National Institute for Occupational Safety and Health (NIOSH) conducted two controlled recirculation tests over three days at a Wyoming trona mine, utilizing an inline booster fan to improve airflow to a remote and difficult-to-ventilate development section. Test results were used to determine the effect that recirculation had on air qualities and quantities measured in that section and in other adjacent areas. Pre-test conditions, including ventilation quantities and pressures, were modeled using VnetPC. During each test, ventilation quantities and pressures were measured, as well as levels of total dust. Sulfur hexafluoride (SF6) tracer gas was used to simulate a mine contaminant to monitor recirculation wave cycles. Results showed good correlation between the model results and measured values for airflows, pressure differentials, tracer gas arrival times, mine gasses and dust levels.

Jan 1, 2013

By J. H. Hill

The globalization of mineral markets and intense competition in downstream mineral-consuming industries such as transportation, agriculture, and construction are requiring raw materials suppliers to innovate, improve quality, invest in new technology, and control costs. Mineral specifications are becoming more refined, and pressure to improve products is felt from increasing numbers of competing producers, substitute materials, customers, and regulators. As a result, engineered mineral products are becoming more like manufactured ones in terms of cost structure, differentiation, and the importance of market driven, customer specific product development. Engineered mineral products are defined as those where the costs of refining and upgrading outweigh those of conventional mining activities (blasting, crushing, classification, haulage etc.), and where close control of physical and chemical parameters is required for customers' processing and manufacturing applications. This includes industrial minerals such as calcium carbonate, kaolin, mica, specialty oxides, talc, and some metal powders. It excludes most metals and bulk commodity materials such as gypsum, lime, sulfur, and soda ash. Engineered mineral products are utilized in common household goods, and are at the forefront of industrial materials engineering in plastics, ceramics, composites, glazes, coatings, and construction materials. As a group, they introduce interesting questions to the minerals firm. Advanced materials or basic? Diversify or specialize? What are the implications of advanced materials and for mineral markets, and most importantly, where can the producer look for long-term value, volume, and profits?

Jan 1, 1993

By William G. Doepken

GENERAL DESCRIPTION The Henderson mine utilizes a highly mechanized, continuous panel-caving system to extract ore from a deep, massive, molybdenum deposit. The mine site, lo¬cated 80.5 km (50 miles) west of Denver, is situated at 3170 m (10,400 ft) above sea level in a steep valley on the eastern side of the Continental Divide. The mill site, located on the western side of the divide, is linked to the mine via a 15.5-km (9.6-mile) railroad tunnel. Mine production is scheduled to reach 27 215 t/ d (30,000 stpd) from the uppermost production level. This pro¬duction rate will have been reached within the four years following an intensive ten-year preproduction development program. A second production level, due to come on stream in later years, will expand production capabilities to 31 751 t/d (35,000 stpd). The mine, which employs approximately 2000, has blocked-out ore reserves of 220 Mt (242 million st) at an average grade of 0.42% MoS2. Geology The Henderson deposit is composed of two partially overlapping ore bodies that lie 1080 m (3600 ft) beneath the peak of Red Mountain. The ore bodies are entirely within a Tertiary rhyolite porphyry intrusive complex that has intruded Precambrian granite. The de¬posit is elliptical in plan with overall dimensions of 670 x 910 m (2200 x 3000 ft). In section it is arcuate with an average thickness of 185 m (600 ft). The top of the deposit is at an elevation of 2610 m (8700 ft) while the lower limits range from 2340 m (7800 ft) on the west to below 2100 m (7000 ft) on the east. The mineralization is relatively continuous in the ore bodies and consists of molybdenite and quartz in random to subrandom, intersecting, closely spaced veinlets. Cavability RQD (rock quality designation) * values measured from Henderson drill core and compared with the RQD values from the Climax and Urad block-cave mines in¬dicated that the Henderson ore would cave but with difficulty and that a high percentage of the cave ma¬terial would be blocky. Initial caving experience shows the Henderson ore caves easier and with greater frag¬mentation than was indicated by the RQD values. Pos¬sible reasons for this are: 1) The greater lithostatic load at the Henderson has a greater effect on caving and fragmentation than anticipated. 2) The relief of confining pressure due to caving action and brittleness of the rock is enhancing breakage. Mine Layout The Henderson mine layout was designed from its inception for a large-scale, rubber-tired, continuous panel-caving mining system. The ore body is vertically divided into three major mine levels (Fig. 1). The top¬most level (8100 level), which is 2469 m (8100 ft) above sea level, is the current mine production level. The intermediate or 7700 level, which is in the initial

Jan 1, 1982

By Cleland N. Conwell

Intermittent coal mining has been conducted in Alaska for over a century. The first report of coal in Alaska was by the Veechy expedition of 1826 and 1827. Whaling ships used coal from Corwin Bluff near Cape Beaufort during the early and latter parts of the 19th century. The first coal mine in Alaska -- and probably the oldest in the Pacific coast of North America -- was opened by the Russians at Port Graham on the southwest tip of the Kenai Peninsula. The mine was operated from 1855 until 1867 when the United States took possession of Alaska. From 1880 to 1915 coal mining was carried on intermittently at several localities including Unga Island, Herendeen Bay, Chignik Bay, Kachemak Bay, and several points along the Yukon River. Small coal mines along the Yukon River provided fuel for the river steamers traveling from St. Michaels to Whitehorse. The area of sustained coal production began with the completion of the Alaskan Railroad from Anchorage to the Matanuska coal field in 1916 and to the Nenana field in 1918. Coal production continued to increase until 1953, at which time the oil and gas fields in Cook Inlet were developed. Oil and gas eventually replaced- the Matanuska coal as a means of providing heat and power. The military in the Anchorage area shifted from coal to oil in 1967 causing a decrease in production. The increased demand for electric power in the Fairbanks area offset the decline and coal production started to increase. In 1969-1970 the Golden Valley Electric Association constructed a mine-mouth power plant 70 miles southwest of Fairbanks near Healy and a power line to Fairbanks. LOCATION OF COALS IN ALASKA Coals are found in all geographical subdivisions of Alaska. Coal in Alaska ranges in age from Carboniferous to Tertiary, and grade from lignite through anthracite. Figure 1 shows the locations of Alaskan coal fields. The only fields that have been developed extensively are the Matanuska and Nenana. Figure 2

Jan 1, 1972

By D. C. Edwards

In an age where customer service and quality drive today's industry and business, no service or product is exempt from these demands. Industry and business are streamlining everything from people to equipment and today have a heavier reliance on the performance and quality of their assets and equipment, (one of the keys to staying competitive). In the mining process industry, the centrifugal slurry pump is a key piece of equipment that keeps product moving and aids in generating revenue for its owner. The continued improvement and customer success lies in a team effort between the mining industry and the pump manufacturers. We, the pump manufacturers, need to keep improving our designs to further extend the life of our pump with fewer failures and promote to our customers proper maintenance of the pumps to continually keep unexpected failures to a minimum. Strict equipment maintenance, as thoroughly demonstrated by the military, is key to the long life and success of any piece of equipment. In the often harsh duty of the centrifugal slurry pump, maintenance is something that requires "attention to detail". No area of the pump is exempt from attentive maintenance. Here, discussions will focus on the areas of the mechanical drive end, wet end, seals, and extended pump shut down and start up. There has not been a slurry pump designed to maintain or repair itself. So in effect, each pump warrants able bodied maintenance persons to maintain them who continually observe all the rules of safety. Prior to any maintenance discussion or action, the issue of safety should always be addressed. Here, as with everywhere, the same rules apply. Work at a safe pace, note all safety precautions, use associated safety equipment and personal protective attire, observe all tagout and lockout procedures, and most importantly, be aware.

Jan 1, 1996

By W. Linwood Haden

Fullers earth has been mined since about 1920 in southwest Georgia and the adjoining area of Florida. In 1935, the mineral was named "attapulgite" after the source of a sample near the town of Attapulgus, Decatur County, Georgia. Mining and processing of the clay was described in a 1930 publication1 at a time when petroleum refiners were the major users. In the years since then, the uses and users of attapulgite have multiplied, and both mining methods and processing methods have been changed to optimize the clay for the new uses. A comprehensive review of the properties and applications of attapulgite 2 has been published. Only a brief review will be given here to explain the properties being sought and to show how these properties are optimized by mining and processing practices.

Jan 1, 1972

By T. Cyrul

The Polish underground mining has its long lasting tradition. High production of coal, that has recently been approaching 200 milion tons per year, put this small country among the bigest world producers of coal. To achieve such a high production, which mainly originate from very unfavourable mining and geological conditions, Polish scientists and engineers have to introduce new and original solutions to the mining practice. Many of the solutions on mining methods, ventilation, stability, subsidence etc., have had the world wide reputation, however, insufficient translations from Polish cause , that many of the recent Polish mining achievements are not known to foreign specialists.

Jan 1, 1986

By H. Ankara

Determining the identicalness levels of the same model trucks working in open pit mine transportation system by means of statistical analysis methods is very significant in terms of availability analysis. In this study, the identicalness levels of two trucks picked randomly from the 170-short-tonne truck fleet working in open pit coal mine over one-year period were examined through a non-parametric test, Mann-Whitney U test for two samples. Time to failures (TTFs) and Time to Repairs (TTRs) of the trucks were analyzed with this test technique and then whether they were identical or not was determined. In order to determine whether the trucks identified to be identical at the end of this test displayed the same mining performances within the same open pit transportation system, the availability analysis of the identical trucks was carried out. As a result of the availability analysis, it was observed that the trucks had availability values that were very close to each other. It was also determined that Mann-Whitney U test could be employed together with availability analysis. Finally, it was observed that Mann-Whitney U test for two samples could yield rapid results in the performance analysis of complex systems like open pit mines.

Jan 1, 2010

By J. R. Henke

Dewatering wells producing iron-rich water experience rapid declines in yield and drawdown due to the formation of ferric (Fe +) hydroxide deposits in well screen, pump intake and riser pipe. Precipitation is caused by a combination of dewatering-promoted iron oxidation and iron-oxidizing bacteria. Physical and chemical well rehabilitation techniques, as well as alternative well construction and well development techniques designed to minimize well clogging, were evaluated in this study. The addition of acid downhole feed systems to dewatering wells prone to iron encrustation can, in some cases, prolong their operational lives up to 500 percent that of unacidified wells.

Jan 1, 1989

By I. Y. Bausov, L. G. Stolarczyk, R. E. Pillmore, A. J. Hillard, J. T. Duncan

"Prevalence of lung disease in younger miners surprised industry regulators, congressional members, researchers and black lung clinic staff members. Mitigation researcher focused on low-coal mining in the Appalachian regions until Miners Colfax Medical Center (MCMC) Black Lung Clinic examinations discovered 25 of 72 Wyoming coal miners with lung disease. To reverse recent upward trend in lung disease, research programatic have been directed at reducing exposure to respirable “float” dust. This paper suggests broadening the scope of research to include boundary detection in efforts to improve outcomes. Beginning with a better understanding of biochemistry of anaerobic bacteria methylation processes precipitating sulfur and heavy metals into thin seam boundary layers. Expanding research and development objective to focused on minimization of bit-pick crushing cone volume and preventing mining thin boundary coal layers and out-of-seam dilution. Black lung clinical evaluations of miner will confirm outcomes directed towards reduced occupational disease and smoke stack emissions. INTRODUCTION Miner exposer to bit-tip crushing cone volume, fragmentation and auger movement generated respirable “float” dust and boiler emissions are related science-technology –engineering-mathematics (STEM) problems. Formidable but not intractable problems are driven by oxidation of upper flood plain elements in the periodic table and biochemical metabolic presses occurring in coal basin. Because of burial compaction, quartz and trace heavy metals (Fe2+, Mg2+) are concentrated in thin seam boundary layers. By not cutting through thin boundary coal layer and out-of-seam into hard quartz containing rock layers, miner lung disease and smoke stack emissions are minimized. Cutting bit-pick elastic wave hydrodynamic principle force vectors in the coal layer must be aligned to minimize respirable dust generation, constrained by fragmentation size. Dust abatement by water spray and machine design are effective; but for, failure to address cutting cone dust volume generation and its distribution along run-of-mine (ROM) transportation systems the boiler. Real-time precision thickness measurements by integrated cutting drum (icDrum) sensor, machine man-interdiction from a dust free control room, is a cost effective way to prevents respirable dust exposure. The recommended STEM research and demonstration initiative addresses issues raised by discoveries of increased rate of lung disease discovered in young miners and concerns over emissions from coal-fired electric generation stations (Global Warming). In-mine demonstrations must be validated by on-site MCMC mobile Black Lung Clinic data acquisition and analysis."

Jan 1, 2016

By Leon J. Jacobs, Kyle R. Ott

This paper discusses design and construction aspects of the tunnel, shaft and station for the Weehawken Tunnel and Bergen line Avenue Station. The project consists of a 1,269 m (4,156 ft) long existing railroad tunnel, which will be enlarged and equipped with a two-track light rail system. The project also includes construction of a deep underground station, with a large shaft connecting the surface station to the below ground station for access and ventilation purposes. Vibration and noise from blasting is a critical community issue and blasting adjacent to two 230-kV duct banks located in the tunnel invert required special blasting procedures.

Jan 1, 2003

By James E. Kolesar

An essential prerequisite to expanding the application of longwall mining techniques in the United States is the development of a better understanding of the mechanics of rock mass deformation near the mined seam, in the inter- burden and at the surface. The results of studies of this type will provide a basis for the development of empirical and/or numerical modeling techniques to predict the rock mass response to mining both near and far from the mined seam. This will lead to improved gate and panel design, resulting in maximum recovery, increased productivity, as well as provide a mechanism for assessing likely surface effects induced by long- wall mining. Presented here is the instrument plan to be used at Kitt Mine No. 1 in the study of rock mass response to two adjacent longwall panels.

Jan 1, 1982

By S. K. Kawatra, V. Claremboux, S. Valluri

Carbon dioxide capture from coal-fired power plant flue gas and subsequent sequestration is expected to play a vital role in mitigating global climate change. To meet the growing need for CO2 capture Technology, Michigan Technological University is researching CO2 capture and Utilization. We have successfully converted CO2 into oxalic acid using an electrochemical approach. If oxalic acid can be produced in bulk from CO2, it can be used to leach rare earth minerals at low cost. Electrochemical reduction of CO2 to hydrocarbons and other chemicals is a complex multistep reaction with adsorbed intermediates. The exact reaction mechanisms leading to various products are not clear from the literature to date and will likely change over the range of conditions like pH, electrode potential, electrolyte medium, catalyst, etc. In this paper, we will present an idea of how the factors mentioned above will effect the electrochemical reduction of CO2 to Oxalic acid. INTRODUCTION. CO2 is thermodynamically quite stable, as shown by its highly negative heat of formation. Thus, it is expected that the formation of any useful chemical from CO2 will require the input of at least as much energy as geological sequestration. However, to be more effective the resulting economic value of the chemical need only pass the cost of the additional energy required beyond geological sequestration. This lends itself to two extremes: one where the quantity of energy required is low and one where the economic value of the additional energy is low. It is expected that CO2 can be reduced via electrolysis to several compounds. Of particular interest are formic acid, oxalic acid, methanol, ethanol, formaldehyde, and carbon monoxide (as a component to syn-gas). These chemicals have been reported as electrolytic products previously in literature and have considerable potential for application. EXPERIMENTAL Electrocatalytic Production of Oxalate from CO2 We are using membrane electrolysis cell to produce oxalate from CO2. A membrane electrolysis cell is a 2-chamber electrolysis cell where the chambers are separated by a selectively permeable membrane. To produce oxalate, a cation exchange membrane (which selectively exchanges cations) was used. Previous literature suggests that in the cathode chamber an organic electrolyte, such as tetraethylammonium perchlorate or tetraethylammonium bromide in dimethylformamide, are preferred3. In the anode chamber, a sodium hydroxide solution water is used. Carbon dioxide is then bubbled into the cathode chamber as a current is applied.

Jan 1, 2019

By J. S. Walstrom

Debate on an appropriate, acceptable method of regulating mine and mineral processing wastes has been ongoing since Congress passed the Resource Conservation and Recovery Act (RCRA) on October 21. 1976. Final regulatory determination on which mineral processing wastes are excluded from the RCRA hazardous waste regulations under the Bevill amendment was made by the U.S. Environmental Protection Agency on June 13, 1991. Regardless of whether a mining or mineral processing facility?s waste stream(s) lost or maintained its exclusion status under the Bevill amendment, that facility can expect more stringent regulation of affected waste streams. These more stringent regulations will be added to an already complex regulatory maze, which includes the Clean Air Act (CAA), Clean Water Act (CWA), Safe Drinking Water Act (SDWA), Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), Superfund Amendments and Reauthorization Act (SARA), and Toxic Substances Control Act (TSCA), as well as state and municipal environmental regulations.

Jan 1, 1992