Search Documents

By A. C. Barlow

The use of deep wells for waste disposal is not a new technique. The production phase of the oil industry has been using this method to dispose of unwanted oil field brine since the 1930's The adoption of this method by other branches of industry, however, to dispose of manufactured wastes is a relatively new development, but one which is finding increased use (2). Deep well waste disposal is not an ordinary technique even though it is finding relatively wide application. In fact, just the opposite is true; it is still a rather extraordinary measure. It is not now, nor is it ever likely to be a disposal method which can be assured of success before it is tried.

Jan 1, 1964

By J. Richard Kyle

Salt domes, their cap rocks, and the adjacent sedimentary strata represent a major economic resource in the Gulf of Mexico basin. Gulf Coast salt diapirs formed in response to sediment loading of the "mother" Louann evaporite sequence of middle Jurassic age, an effect that is caused by the buoyant nature of the lower density salt. Halokinesis progresses from nonpenetrative deformation that creates broad "pillow" structures into discrete high-amplitude diapirs. Because of its buoyancy, the top of the salt diapir remains near the land surface or the seafloor during much of its history as the basin floor subsides. The salt within the Gulf Coast diapirs is deformed complexly and commonly shows subvertical banding that represents modified sedimentary layers with different contents of nonhalite components. The most abundant impurity is anhydrite, which occurs as individual millimeter-scale crystals or as deformed clasts that generally form about 5% of most salt stocks. Many mature salt diapirs are mantled by a "cap rock" that consists of a lower anhydrite zone and an upper calcite zone, commonly separated by a discontinuous gypsum-bearing zone. The anhydrite zone forms as accreted layers of anhydrite grains and clasts that are left after episodes of halite dissolution. The calcite zone is a product related to petroleum destruction accompanying bacterial reduction of aqueous sulfate. Calcite-cemented siliciclastic strata occur above or alongside diapirs. The mineral resources of the salt-dome setting are remarkably diverse. Major economic products of the salt-dome environment are salt and cap-rock-hosted native-sulfur deposits, as well as petroleum resources that occur on the dome flanks and in the cap rock. Native sulfur forms as a result of bacterial sulfate reduction accompanying petroleum destruction to form hydrogen sulfide, which is subsequently oxidized to elemental sulfur, major amounts of which have been produced by the Frasch process from Gulf Coast salt-dome cap rocks. Some cap rocks have produced limestone, gypsum, and anhydrite for a variety of construction uses. Although traditional industrial-mineral resource production from Gulf Coast salt domes is shrinking, some cap rocks host potentially commercial concentrations of celestite and barite, as well as the metals Zn, Pb, and Ag. Furthermore, caverns, excavated within the salt stocks, serve as major storage facilities for crude oil (including the Strategic Petroleum Reserve), liquefied petroleum gas, and natural gas. These resources are products of fundamental geologic processes that are integral to the evolution of the Gulf of Mexico basin. Whereas production of some industrial-mineral resources, such as elemental sulfur, has declined in recent years, ample reserves of salt will allow production to continue into the foreseeable future. Further, there is potential for other mineral-resource production from cap rocks under favorable economic circumstances. Expanded use of caverns, excavated in the salt masses for material storage and disposal, is likely to continue into the next century.

Jan 1, 1999

By Michael E. Mcllwain, Lee O. Nelson, Robert D. Rogers, James H. Wolfram

Examination of the economics and environmental consequences associated with phosphate fertilizer production documents the necessity for development of innovative production technologies. Evidence of phosphate ore's susceptibility to microbial alteration indicates that it will be an ideal candidate for industrial-scale bioseparation. There are at least two applications for the biosolu- bilization technology: (1) an industrial-scale bio- process similar to the presently used wet acid process and (2) production of small prills (bio- bead) containing unprocessed rock phosphate and the biological ingredients necessary to promote phosphate solubilization. At the present stage of development, the biobead technology is the preferred application. It is an energy-efficient "green" technology that will dramatically reduce the amount of solid waste and air emissions produced by the phosphate industry.

Jan 1, 1999

By William H. Dresher

Introduction A subject long debated but rarely resolved involves the interaction between the academic community and industry in the sponsorship and conduct of research. The subject is, unfortunately, too often treated as a controversy involving ethics and the profit motive. But, in fact, the two branches of society - industry and academia - are necessarily part of the same system. In the last 25 years, the realization has developed that research alone is not sufficient to bring about use of those results to benefit society through productivity gains and economic growth. The flow of events shown in Fig. 1 was generally believed to be the steps required for reaping the benefits of research. Today, research still has the very important role of creating new information or new ideas. However, it is recognized to be but one of many steps in a process that we now refer to as technological innovation. Charpie (1967) said, "Technological innovation is the driving force behind economic growth in the US. In this context, innovation means the process by which a new idea is successfully translated into economic impact within our own society, by providing better products, and simultaneously creating new jobs in the manufacturing of those products. Only after an investigation is put into sufficient use to have an economic effect, is it termed an innovation." One of the best depictions of the technological innovation process is shown in Figs. 2 and 3. These are adapted from Haeffner (1975), and modified by the Committee on Mineral Technology of the National Research Council (1981). Figure 2 identifies the many steps involved in the process. It designates a generalized form for interaction between the academic community and industry. Figure 3 identifies the steps in the "innovation activity" box of Fig. 2. Academia is generally responsible for developing of new knowledge and ideas, as well as maintaining and enlarging the collected body of scientific knowledge. Industry is responsible for developing new products, methods, and processes. Both institutions operate for the benefit of society, but under different driving forces. In academia, the driving force is the achievement of academic excellence. In industry, the driving

Jan 10, 1984

In 1991, Placer Dome Venezuela established a 70% stake in Minera Las Cristinas, to mine the Las Cristinas gold deposits in Bolivar. This case study examines the multi-sectoral partnership arrangement that was developed to improve health services near the proposed Las Cristinas gold mine. The investment climate in Venezuela is uncertain and the socio-economic circumstances are potentially hostile. Despite that, the partnership between the mining company, local communities, government agencies and an international health nongovernmental organization (NGO) collectively leveraged nearly $2.5 million to build and operate a community health center.

Jan 1, 2002

By Michael J. Hannan, Thomas F. Torries

The nature of industry structure is examined and the structure of the aluminum, copper, lead and zinc industries are described by the use of factor analysis. Capacity is defined and the relationship between industry structure and capacity utilization is examined. It is demonstrated that excess capacity is possible in industries with competitive or monopolistic characteristics, but the effects of the overcapacity are vastly different in the two cases. In a competitive industry, cycles of overcapacity with attendant fluctuating prices are expected. A change in industry structure from monopolistic to competitive characteristics over time causes profits and economic rents to be transferred from the producer to consumers of the mineral.

Jan 1, 1989

The development of technologies to improve mining and mineral processing is an ongoing process. These new technologies are the result of the industry’s drive to lower costs and improve productivity. Many technical conferences allow mining industry professionals to learn about these new technologies and possibly implement them in their own operations. In early November 2005, The 14th symposium on Mine Planning and Equipment Selection (MPES) was held in Banff, Alberta. It was jointly held with the Fifth International Conference on Computer Applications in the Minerals Industries (CAMI).

Jan 1, 2006

By Steve Kral

The former mayor of Los Angeles, CA is a believer in public transportation but thinks neither his city nor the entire country is spending enough on basic infrastructure. In fact, the United States has fallen behind most other developed nations in improving public transportation, the former mayor said. Antonio R. Villaraigosa was the keynote speaker at the North American Tunneling (NAT) conference, held June 22-25 in Los Angeles, CA. The event, held every two years, is sponsored by the Underground Construction Association of SME (UCA). This years? conference attracted 1,091 underground construction professionals from around the world. The accompanying exhibition continues to grow, attracting 142 exhibiting companies occupying 162 booths. As always at NAT, registered attendees received the proceedings volume of the conference, which contains 132 papers. The proceedings volume, including a CD of the papers, is available from SME for $149 member, $139 student member and $189 nonmember. The book can be ordered from SME, NAT item #400-4, phone 303-948-4225, 1-800-763-3132, or online at www.smenet.org/store.

By Georgene Renner

With more than 800 booth spaces sold and 540 exhibiting companies displaying their wares, there was something for everyone on the exhibit floor of the 2014 SME Annual Meeting in Salt Lake City, UT Feb. 23-26. The following is a sample of what was offered at the 2014 meeting.

Accidents that resulted in 16 deaths in three West Virginia coal mines, two in Kentucky and one in Utah have government and industry re-evaluating current safety regulations. Even though U.S. mines continue to improve on their safety records, the deaths reminded the industry and state and federal agencies that mining remains a dangerous business. Even so, data from the U.S. Mine Safety and Health Administration (MSHA) show that new technologies and a highly trained workforce has allowed the nation’s coal mines to increase production while providing safer workplaces. Since 1970, coal production at U.S. mines has increased by about 83 percent. During the same period, fatal injuries have fallen by 92 percent. And more than half of the U.S. coal mines operate each year without a lost-time injury. In 2005, there were 22 deaths in U.S. mines, a record low.

Jan 1, 2006

By E. R. Hendrickson

About 1/3 of the world's supply of phosphate rock is produced in a relatively small area of the Florida peninsula east of Tampa. Until this past year, a circle with a radius of about 25 miles and centered on Bartow would encompass the major producing areas. During the past year producing areas have opened in North Florida which promise to vie with the Polk-Hillsborough County area in terms of proven reserves. In addition, new phosphate production is planned for counties to the south and west of the present fields. From the existing production areas, however, more than 19 million long tons of phosphate were mined in 1965. As mining engineers most of you probably are familiar with the methods of mining and beneficiating the pebble phosphate rock. You thus recognize that, although some water quality problems may arise from these processes, there is no potential air pollution problem. To make an economically useful product, however, further processing must take place. It is from this additional processing that potentially damaging materials may be discharged to the atmosphere.

Jan 1, 1966

By William H. Dresher

A recent report to President Reagan from the Business-Higher Education Forum, entitled, "America's Competitive Challenge: Need for a National Response," (1) observes that in the recent past, ". . . much of that research, which is necessary for major breakthroughs and sustained productivity improvements, was redirected to short-term objectives ... At the same time, American universities, which conduct more than half of the nation's basic research, have suffered from an accumulated under-investment in facilities and equipment amounting to an estimated $1-4 billion." Also contributing to the decline in America's productivity, the report said, are "...weak technology transfers between government and industry and between universities and industry..." This report as well as other recent reports and articles have, reopened a subject which has long been debated but rarely resolved-- the interaction between the academic community and industry in the sponsorship and conduct of research. The subject is unfortunately, too often treated as a controversial issue involving ethics and the profit motive when, in fact, the two branches of society -- industry and academia -- are necessarily part of the same system. I would like to speak to you today on the subject of university-industry interactions and to some extent discuss the role of government in such interactions. Finally, I will make some remarks as to how this subject applies to the mining industry.

Jan 1, 1984

By D. C. Wilder

Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed. but neither sheared nor faulted. Furthermore. thermal deformations in faulted or sheared rock were not significantly recovered during subsequent cooling thus a permament deformation remained. This inelastic response is in contrast with elastic behavior identified in unfaulted and unsheared rock segments. A companion paper (Butkovich and Patrick, 1986a) indicates that deformations in un- sheared or unfaulted rock were effectively modeled as an elastic response. We conclude that permanent deformations occurred in fractures with crushed minerals and fracture filling or gouge materials. Potential mechanisms for this permanent deformation are asperity re-adjustments during thermal deformations. micro-shearing, asperity crushing and crushing of the secondary fracture filling minerals. Additionally, modulus differences in sheared or faulted rock as compared to more intact rock would result in greater deformations in response to the same thermal loads.

Jan 1, 1986

By Walter Hermülheim, Klaus-Dieter Beck

In German hardcoal mining approximately 1 or 2 cases of spontaneous combustion are recorded per 10 million tonnes of saleable output. In approximately every 20th spontaneous combustion case, CH, is ignited. By the example of a fire caused by spontaneous combustion on Friedrich Heinrich colliery, an overview on the measures taken for firefighting and explosion prevention is given. These measures comprise (in sequential order) - early fire detection by CO-monitoring, - gob-sealing measures against ventilation air leaks, - full-space inertization of the coalface subsequent to a CH,- deflagration, - installation of a target inertization of the caved-in gob under the protection of the full-space inertization, - re-opening of the fire zone and reestablishment of the ventilation-air current, - completion of the salvaging work with continued target inertization of the caved-in gob and further sealing measures (monolithic packing), - sealing of the coalface after salvaging. The measures described allowed gain of control of a safety- critical (because close to the face) gob fire caused by spontaneous combustion, in spite of a CH, deflagration, within few days only, and salvaging of equipment from that coalface and start-up of the follow-up coal-face on schedule. The measures taken as well as the experiences gained allow deduction of general safety criteria for fighiing of gobfires caused by spontaneous combustion, and for controlling the explosion risk. e.g. - warning and alert thresholds for early detection of fires, - criteria for spotting of the zone of fire, - rules for tightening caved-in gobs, - thresholds for the retreat of firefighting crews from the vicinity of the zone of fire, and for starting ineiization, - considerations for positioning of and strength requirements for stoppings with/without inertization, - flow-by-volume adjustment of inertization, - safety rules for work with respiratory apparatus in the inertized zone, - safety rules for the re-opening of zones of fire. The considerations end up in the conclusions that the duration in terms of months of the classic cycles of sealing, waiting, and reopening can nowadays be reduced to a few days only by purposeful combination of full-space inertization and locally confined tar- get inertization of the gob area. The earlier high risks incured by the mine resuce squads en- trusted with sealing of zones of mine fires under explosion hazards can be reduced by the method described, provided the safety regulations are conformed with. In this way, intertizing contributes substantially to reduction of down-time caused by mine fires, to preservation of recoverable parts of the deposit, and to improved safety of the fire-fighting crews.

Jan 1, 1997

Coal-derived flue gases contain CO2/SO2 and these contaminants preferably have to be captured by cheap sorbents. This remediation approach is from the standpoint of addressing issues such as global warming, acid rain and development of Advanced Power Generation Systems and to realize the economic gain as well. Conventional and existing dry scrubbing technologies use regenerable sorbents which are pollutant specific and require expensive stabilizers in order to attain versatility. This paper discusses the use a novel class of sorbents prepared from the heavy metal contaminated Berkeley Pit water (Butte, Montana) by a proprietary process developed at The University of Nevada, Reno. These sorbents are activated mixed spinel ferrite (MxFe,_X04)' Preliminary experimental results show that the sorbents have good desulfurization and CO2 decomposition capacities. The decomposition effectiveness of these mixed spinel ferrites was studied at 300°C and compared against the synthetic magnetite obtained from ferrous sulfate solution in our laboratory. The results indicated that the mixed spinel ferrite had good affinity for the adsorption and decomposition. The CO2 decomposition data of both sorbents fitted the first order reaction kinetics. Even though the surface area of the magnetite was higher than that of mixed spinel ferrite, the CO2 decomposition rate of the mixed spinel ferrite was estimated to be 2.5 times higher than that of magnetite under identical conditions. The carbon analysis deposited on the sample indicated that the CO2 was 100% decomposed into carbon and other carbon! hydrogen compounds by the mixed spinel ferrite whereas the conversion was 43% by the magnetite. In terms of specific adsorption of carbon, ferrite was 3-5 times more efficient than magnetite.

Jan 1, 1996

By R. S. Conti

The US Bureau of Mines (USBM) has developed an inflatable feed-tube seal (IFTS) for high-expansion foam generators. The IFTS is a lightweight, portable, rectangular inflatable bag that can be used by firefighters to rapidly seal large openings, such as those in underground mines, and to simultaneously provide a feed-tube for a high-expansion foam generator. Thus allows fire fighting foam to freely flow to the fire site and control or extinguish the fire. Studies indicated that a high-expansion foam plug will travel 183 m (600 ft) down an entry with a 4.5% rise in elevation, before leakage of foam from around the inflatable partition.

Jan 1, 1996

By C. Zhou, C. C. Jobes, J. H. DuCarme

"Magnetic proximity detection systems (PDSs) are used with continuous mining machines (CMMs) to protect miners from striking and pinning accidents. Generators are used in a PDS to create magnetic fields covering the space around a CMM. The PDS determines the proximity of a miner relative to the CMM based on the magnetic flux density detected by a miner-wearable component (MWC) and simultaneously alerts the miner and stops the motion of the CMM if the miner is within a proximity that creates a striking hazard. A stable magnetic field is essential to the accuracy of the proximity calculations performed by the PDS. This paper presents the results of a systematic study of the magnetic influence of two types of steel structures found near a CMM—the body of the CMM itself and the wire mesh used for roof and rib control. The results show that the steel of the CMM body can change the magnetic field distribution and also alter electrical parameters of a PDS by changing its generator current. The study also shows that, depending on the distance between the wire mesh and a generator, the magnetic field can also be altered. INTRODUCTION Continuous mining machines (CMMs) can be up to 10 m (33’) in length and more than 3 m (10’) in width. These machines perform the coal cutting operations in underground room-and-pillar coal mines. Accidents during CMM operation accounts for an average of 250 injuries every year, and 43 miners have been killed by striking or pinning accidents involving CMMs in the United States from 1984 to 2015.Because of these fatalities and injuries, the Mine Safety and Health Administration (MSHA) promulgated a regulation in 2015 that requires the use of proximity detection systems (PDSs) on all CMMs with the exception of full-face machines (Mine Safety and Health Administration, 2015). Currently, there are five different proximity detection systems that MSHA has approved as permissible for use in U.S. underground coal mines (Mine Safety and Health Administration, 2013). All of these PDSs rely on a miner-wearable component (MWC) to detect the generated magnetic fields that PDSs produce around a CMM (Schiffbauer, 2002). These systems use the magnetic field strength readings in terms of magnetic flux density from the MWC to determine whether a miner is at a safe distance from the CMM. A stable magnetic field is essential for the accuracy of a PDS."

Jan 1, 2018

By Eugie Kabwe

The velocity of detonation (VOD) is a significant property considered when rating an explosive, and it is quantified as a confined or unconfined velocity. The confined velocity is more significant as explosives are usually used under a definite degree of confinement. This study evaluates the stepwise increment of the air-deck volume from 10 to 30 percent, and its effect on the VOD. The VOD estimation in the 172-mm-diameter explosive column was conducted using the Dáutriche technique. The air-deck volume increment has an attenuation effect on the steady-state VOD, and detonation failure is high at 30 percent air-deck volume. This attenuation effect is directly linked to the explosive’s rating and efficacy. The air-decking approach in this study is different from conventional air-decking techniques in that it does not employ the fixed blasthole parameters, air-deck volume and specific VOD. 

By Eugie Kabwe

The velocity of detonation (VOD) is a significant property considered when rating an explosive. It may be quantified as a confined or unconfined velocity. The confined velocity is the rate at which the detonation wave propagates through an explosive within a blast hole or any restrained space. The unconfined velocity emanates when an explosive is detonated in the open. However, the confined velocity is more significant as explosives are usually employed under a definite degree of confinement. This paper evaluates the increment of air deck volume and its effect on the VOD. The air gap (air deck) volume is increased stepwise from 10 to 30% of the total blast hole volume by reducing the stemming height in the collar zone. Thereafter, the VOD estimation in the 172-mm-diameter explosive column is conducted using the Dáutriche technique. It is observed that the VOD reduced with the increasing air deck volume and detonation failure is high when 30% of the blast hole volume is replaced with air deck. It is deduced that the increment of the air deck volume has an effect on the attenuation of the steady-state VOD.

By Eugie Kabwe

The velocity of detonation (VOD) is a significant property considered when rating an explosive. It may be quantified as a confined or unconfined velocity. The confined velocity is the rate at which the detonation wave propagates through an explosive within a blast hole or any restrained space. The unconfined velocity emanates when an explosive is detonated in the open. However, the confined velocity is more significant as explosives are usually employed under a definite degree of confinement. This paper evaluates the increment of air deck volume and its effect on the VOD. The air gap (air deck) volume is increased stepwise from 10 to 30% of the total blast hole volume by reducing the stemming height in the collar zone. Thereafter, the VOD estimation in the 172-mm-diameter explosive column is conducted using the Dáutriche technique. It is observed that the VOD reduced with the increasing air deck volume and detonation failure is high when 30% of the blast hole volume is replaced with air deck. It is deduced that the increment of the air deck volume has an effect on the attenuation of the steady-state VOD.