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By Cyrus W. Field

Metalliferous sediments constitute an important component of the sedimentary veneer that overlies basaltic oceanic crust of the Nazca Plate and elsewhere. Although first collected more than one century ago near the East Pacific Rise during the Challenger Expedition and recognized for their anomalously high content of Fe and Mn, occurring as very fine-grained, yellow-orange, oxides, hydroxides, and oxyhydroxides, it was not until the more detailed studies of Bostrom and Peterson (1966) that their geologic significance and concentrations of other transition metals were fully appreciated. The Nazca Plate is a dynamic lithospheric unit bordered by the Peru-Chile trench and the East Pacific Rise to the east and west, and by the Galapagos Rift and the Chile Rise to the north and south (Fig. 1). Samples employed in this study were taken from piston core recovered from the Nazca Plate (Fig. 2), D. S. D. P. drill core from the northeast Pacific (Dymond and others, 1973), ferromanganese nodules from dredge-haul s at several locations, and from hydrothermal mineral deposits of the Andes. Our efforts have been largely sponsored by the National Science Foundation through its International Decade of Ocean Exploration Pro- gram. The metalliferous fraction of these sediments is widespread, but generally small. Sedimentation is dominated by biogenic silica in the equatorial latitudes, terrigenous debris adjacent to the South American Continent, and by biogenic carbonate elsewhere, except at depths below 3500 m in the central and northwest parts of the Nazca Plate near the East Pacific Rise. Contributions of these distinctive sediment types are shown by the distributions of Si02, A1203, and CaC03 given in Figure 3.

Jan 1, 1982

By Jack G. Crump

Nuclear radiation systems for gauging solids content in process slurries and level in crushers has demonstrated acceptance in ore processing. The use of nuclear radiation for moisture analysis of bulk materials is presently receiving acceptance in beneficiating and agglomerating processes. On the horizon is the use of nuclear activation methods for continuous, qualatative and quantitative analysis of concentrate. The common characteristics of these uses of radiation is the non-contacting nature of the measurement. Unquestionably, this is the dominant reason for acceptance of nuclear methods in level and slurry-gauging. Moisture activation analysis of a product using nuclear methods retain this advantage. However, and: more importantly, they offer new solutions to old problems. The nuclear method in addition to being non-contacting, is non-destructive and provides a continuous measurement of the process variable. The system responds: to the fundamental makeup of matter, mass and elemental composition, not to secondary properties such as temperature, resistivity, or dielectric constant. Measurement is a volume rather than a surface phenomenon, thus the results can provide a truer pricture of the measured variable.

Jan 1, 1965

By Peter Keppler, Charles Jackson

WHY DO AN AUDIT? There is increased enforcement of environmental laws and regulations at State and Federal levels with attendant steep fines and even the possibility of jail sentences. We are all aware of environmental and public health and safety incidences (i.e., Love Canal, Bhopal) which have led to stringent laws and regulations (i.e., CERCLA, RCRA, SARA). In some cases, the courts have specified that a company institute an audit program as a condition of settlement of claims which related to lack of environmental control. The U.S.EPA issued an Environmental Auditing Policy Statement in the November 8, 1985 Federal Register (pp. 46504-46508) which encourages the use of environmental auditing by regulated entities. Elements of what EPA considers to be an effective environmental auditing program are outlined and briefly explained. These factors combine to indicate why there is a growing number of companies which have instituted an audit program. Briefly, the program can and should be used to monitor compliance with environmental regulations and corporate policy, to prevent violations, to improve policies and procedures, to raise the level of environmental awareness, to encourage communication among operations and all management levels about environmental problems, and to measure risks and control costs. AMAX Inc. has had an environmental audit program since the early 1970's. The AMAX Environmental Affairs Department, working with the Law Department, oversees and coordinates environmental audits and analyzes the findings which an audit reveals. Facilities are audited on a regular schedule; those having the greatest potential for environmental liabilities are audited at least annually; other facilities are audited less frequently. The question of who performs the AMAX audits was settled in favor of the audit team being independent of personnel from the facility being surveyed. Other methods of auditing could be the following: - Independent contractor (Appendix A) - Combination of independent contractor and in-house staff - Self-audit by site personnel The merits and demerits of who should conduct the audit can be analyzed to suit your particular needs. Next you need to decide on the procedure for the audit and the form for reporting and follow up. Environmental publications referenced in Appendix B can be helpful to you at this point. After deciding on the form of auditing, a schedule is prepared and followed to the closest extent possible. This schedule should be published and distributed to the sites so facilities know when they are being audited. This is not designed to be "a game of hide and seek." Various elements of the AMAX Audit Program are as follows: Team selection Pre-visit preparation Site visit Exit interview Report Using the audit Follow-up Team Selection The usual make-up of the team is the audit manager, the environmental specialist who normally provides assistance to the site or has knowledge about the operation, and a legal representative if his or her schedule allows. The legal representative will review the findings of the audit team if a personal visit is not timely or necessary. Size of the team can be expanded, but a minimum of the audit manager and the environmental specialist is best. Two sets of observations are better than one. The environmental specialist can also provide the rapport which is beneficial to creating the appropriate tone so that the site people will be as cooperative as possible. This is not to be an antagonistic exercise.

Jan 1, 1991

By Richard Snyder

Secretariat of the Coal Mining and Mining Executive Committees' of the National Safety Council (NSC) and Manager of the memberships to both Mining Sections; Senior Consulting Safety Engineer, NSC; member of several committees for consensus Standards of the American National Standards Institute (ANSI); a Certified Safety Professional (CSP) of the Board of Certified Safety Professionals of the Americas, Inc. and a chief proctor for CSP testing and certification procedures, et al. It appears that the tunneling trade is merging into its own renaissance for the decade of the 1970s', and most likely on past the year 2001. Federal interest in underground excavation, and more specifically, rapid excavation expertise has been on the upswing since the latter part of the 1960's, mainly due to the pressing national needs for more raw materials based on the rise for material goods and the projective gloom of possible power shortages. On the pure tunneling side the national needs encompass, in the mainstream of priorities, rapid transportation and water supply excavation as the two top contenders. For instance, the estimates for tunnel mileage for the period 1968-1975 are:(1) Subways---85 miles Urban Highways--- 123 miles Intercity Highways---210 miles Water Supply Routes---528 miles at a total of 946 miles of tunnels. The estimated cumulative underground excavation demand in dollar amounts for the period 1970-1989 are:(1) Construction Oriented Demand--- $35 billions Mining Oriented Demand---$34 billions (which includes the coal-oriented demand on the order of 26 billions.

Jan 1, 1997

By D. C. Torre

Ever since the early '60's there have been efforts to develop and produce reliable continuous haulage systems capable of taking the full output of a continuous miner and transporting it, in one continuous flow, from the face to the tipple. The majority of the continuous haulage systems which have been most successful to date were placed in operation in the early '70's and were all of the bridge conveyor type, usually consisting of bridges and mobile bridge carriers attached at the inby end to the continuous miner and at the outby end to the panel conveyor itself. These successful bridge conveyor type continuous haulage systems were, and continue to be, either of the belted or chain type. Undoubtedly, the most successful belt type continuous haulage systems are those manufactured and marketed by the Long-Airdox Company. Until early 1977, the most successful chain conveyor type haulage systems were manufactured and marketed by Jeffrey Mining Machinery Division. In 1977, Long-Airdox reentered the market with a chain type system to complement its belted system. I say "reentered" because the original bridge type continuous haulage system was introduced to the coal mining industry in the early '60's by the old Long Company, a predecessor of the current Long-Airdox Company, and those original units were of the chain conveyor type.

Jan 1, 1981

By H. Marshall Farrier

In the past few years the world petroleum industry has increasingly felt the weight of changes in the principal economic factors affecting pro¬fits. As a result of, these changes, it has been necessary for many oil companies to acquire certain new facilities in order to strengthen their competitive positions and thereby protect their tremendous investments in crude oil reserves, pipe line facilities, refining operations, and marketing outlets. Principally these needs have been met by new capital outlays. A supplementary, method of acquiring needed facilities, however, has been to obtain existing facilities through complete or partial acquisition of other companies.' properties. It is this method of meeting competitive pressures with which this paper is concerned. This paper presents a statistical breakdown of the mergers and acquisitions which occurred in the oil industry between January 1, 1954, and October 1, 1959, showing the frequency' with which certain types of properties were acquired in each of the years studied. In addition, it discusses the principal economic conditions which stimulated many of these property trans¬fers, comments on the effects of these mergers on the consuming public, and indicates the types of, mergers and the rate at which they may be expected during the next three or four years. The basic data upon which the statistical analysis presented in this paper is based were taken from several published sources. Obviously they are somewhat incomplete because not all mergers and acquisitions were reported However;, a careful search was conducted through, The Wall Street, Journal, The Oil and Gas Journal, Potroleum Week, and The Oil Daily with the result that the data should be reasonably complete and comparable for each of the years studied, It is believed, therefore, that the statistical analysis which' follows provides a reasonably accurate indication of the general trend in mergers and acquisitions during the period studied.

Jan 1, 1960

By Robert D. Harris

In 1958, the coal industry, through Bituminous Coal Research, Inc., and the electric utility industry, through the Edison Electric Institute and the Association of Edison Illuminating Companies, initiated a joint program to study coal pyrite and its removal as a means of lowering the sulfur content of steam coals. It was assumed that significant amounts of pyrite often remained in washed steam coal not because available systems for coal cleaning were inadequate, but because the pyrite was small and widely disseminated, During the first two years, samples of coal were examined petrographically to determine the size, association, and mode of occurrence of the pyrite in the raw coal and in the products of laboratory separation, Samples of coal were also pulverized in different equipment to determine how effectively pyrite was released by pulverization and if the mode of pulverization affected the liberation of pyrite. From these studies, the following tentative conclusions were made (1 ): 1. Much of the coal pyrite is within a 250-70 micron size range, and therefore is too small to be removed by conventional coal cleaning, but relatively large when compared to the size of coal as pulverized for combustion in large boilers. 2. The degree of pyrite liberation is mainly determined by the size of the product and not by the type of crusher. 3. For improved pyrite removal, the coal should be cleaned during or after pulverization at the power station.

Jan 1, 1965

By J. A. Haggman

In a country richly endowed in mineral wealth, Climax Arimco Mining Corporation's (CAMC) Dinkidi porphyry Au?Cu deposit in Nueva Vizcaya province, Philippines, represents the most significant mineral discovery in the country in recent times. The deposit is located within a belt of young intrusive and volcanic rocks in the Sierra Madre mountain chain of north Luzon a region previously unassociated with porphyry-style mineralization. Since 1989, drilling of the Dinkidi deposit has outlined a resource of 124 million tonnes of 1.0 g/t gold and 0.41 % copper. Regional exploration throughout CAMC's 37,000 hectare FTAA has identified a further sixteen potential porphyry-related deposits. A new mining law was passed in March 1995 but prior to that CAMC had the first Financial and Technical Assistance Agreement (FTAA) granted by the Philippine government allowing 100% foreign ownership of mining projects.

Jan 1, 1997

By I. J. Wu

China’s land area, comparable in size to United States or Canada, contains diverse geological environments and mineral resource potential. The diversity in geological environments is such that the potential for developing many world-class mineral deposits in China is good. However, China’s mining sector was not open to foreign investment until the1990s. The long-term prospect for Chinese resource development is attractive because of China’s enormous population and cumulative demand for minerals. Approximately 33 foreign mineral companies, including 11 major internationals, are to various degrees active in China. Chinese mining laws and regulations pertaining to joint ventures with foreign companies are, from the international investment prospective, evolving slowly, but positively. This positive trend is continuing under the current government reform process, which is moving China towards a freer market economy. Although improving the enforcement of relevant laws and regulations is an ongoing process, the environment for mineral investment and joint ventures is increasingly more accommodating to foreign companies.

Jan 1, 2000

By J. W. Parkinson

With most of the coal currently mined in the eastern U.S. already requiring cleaning to meet electric utility coal specifications, the question remains how medium- and high-sulfur coal producers will provide the even better quality coal expected to be demanded if pending acid rain legislation is enacted. One emerging approach is to crush the coal to liberate additional ash and sulfur so that better quality coal can be produced at equal yields. This paper discusses how to measure liberation. the premiums the utility market is willing to pay for lower sulfur coal, and a staged middlings crushing scheme that promises the benefits of total raw coal crushing but at lower costs. For some coals, cautious application of liberation concepts may be the only way to produce a product that can be quality and cost competitive in the future utility coal market.

Jan 1, 1988

By S. G. Britton

Thin seam mining presents unique challenges when management or economic conditions require significant productivity increases. These challenges are increased depending upon the presence of various external factors such as labor unions, Federal and state regulations, and market characteristics. This paper explores the turn-around situation occurring at Tanoma Mining Company (TMC), a medium-sized underground coal mining company in central Pennsylvania, USA. Using a systematic approach of improving management controls and direction, labor relations, and communications, coupled with an intensive upgrade/rebuild/replacement program for equipment and systems used at the mine, TMC has begun reversing its' cashflow position from negative to positive within two years.

Jan 1, 1991

By L. M. Gochioco

The U.S. coal industry is under-going dramatic changes to meet the challenges of the keenly competitive fuels market. The application of innovative technologies is needed to improve safety and to increase productivity in order to make coal more competitive as a fuel. As more coal companies shift into capital intensive longwall mining, there is a clear need to invest more in exploration before mine plans are made. Coal seam anomalies may create adverse mining conditions. The early detection of these anomalies could make the longwall mining safer and more productive through improved planning. A standard exploratory drilling program can provide only limited geologic information. The seismic reflection technique can be used to detect coal seam anomalies and is effective in reconnaissance surveying. Recent advances in the quality of coal seismic data have increased the success rate of seismic surveying. Therefore, surface seismic surveys, coupled with selective drilling, will come to play an integral role in coal exploration in the 1990s.

Jan 1, 1990

By H. Sevim

Three transportation and handling alternatives for delivering dry coal combustion residues from power plants to underground coal mines were evaluated technically and economically. The objective was to transport, handle, and inject the residues into the old workings of the mine at a minimum cost. This objective was accomplished in two steps: I) Simulation models were developed and utilized in identifying technically feasible designs in each alternative, 2) Technically feasible designs were economically evaluated to obtain the cost-per-ton of material transported. The designs that provided the minimum cost-per-ton were declared optimal An analysis was conducted for varying distances and tonnages to reveal favorable operating ranges of each alternative.

Jan 1, 1996

By A. T. Iannacchione

Unrecognized roof beam failures resulted in 69% of the falls of ground injuries occurring in underground U.S. stone mines from 1990 to 1996. Field investigations at 45 underground stone mines suggest that excessive beam sag or deflection is the principal unstable roof behavior characteristics associated with miner injuries. Laminated roof structures, common in most underground stone mines, allow the immediate roof to separate into distinct beams. The timely determination of roof beam deflection could provide stone miners with advanced knowledge of potentially hazardous roof. Existing methods to assess roof conditions consist of observational and monitoring techniques. Observational techniques include open drillholes, sounding, wedging, and borescopes. Monitoring techniques include scratch tools, extensometers, telltales, Miners Helpers, and Guardian Angels. 1 Miners have difficulty utilizing these techniques because roof beams are located an average of 8 m (26.5 ft) above the miner's head in environments that are dark, dusty and noisy and these deflections are measured in millimeters of movement. To help mitigate the potential for falls of ground injuries to underground stone miners, the National Institute for Occupational Safety and Health (NIOSH) has developed the Roof Monitoring Safety System (RMSS) to aid in monitoring dangerous levels of roof beam deflection. If enough site-specific information is collected and placed on highly visible maps, individual mining operations could establish general guidelines for responding to specific roof beam deflection occurrences. This would help in implementing a pro-active, comprehensive roof control plan for reducing falls of ground injuries.

Jan 1, 1999

By Doug Halbe

A number of CIP plants have been built in Western Australia in the past two years. The authors have surveyed several of these new plants and present drawings, data and discussion of operating and design innovations and areas of interest.

Jan 1, 1982

Newmont has been producing gold from the Carlin Trend for over 45 years. Naturally the focus, scale and complexity of the operations have changed considerably over this time. Newmont discovered and developed the Carlin Main ore body which is located about 32 km (20 miles) north of Carlin Nevada. The property was developed as a one mine one gold mill treatment plant operation which produced about 6,200 kg (200,000 Troy ounces) of dorè gold bars per year. The initial mine, mill and gold refining facilities were relatively small in comparison to today?s standards. The milling circuit used the Merrill-Crowe zinc precipitation process to recover dissolved gold and prepare a concentrated precious metal ?precipitate? to be melted into a dorè bar for sale.

Jan 1, 2012

By L. H. Michaud

An existing mining company plans to extend their surface coal mining operations in central Pennsylvania. Although the proposed site contains pyritic material, the results of the acid-base accounting for the site show an overall NP:MPA ratio of 4.26:1 for the entire site. The pyritic material is, however, associated with the lower of the three seams to? be mined. If traditional dragline mining methods were used, this would result in the acidic material being placed at the top of the spoil piles, exposing it to air and water, and therefore to the formation of Acid Mine Drainage (AMD). Further concerns are associated with the fact that the alkaline material is not distributed evenly over the mine site. In order to prevent the formation of AMD, the company has proposed to mine the area using Truck/Shovel mining methods. This technique offers a more flexible alternative for cut sequencing and for the selective placement of waste material. Working with the Department of Mineral Engineering at The Pennsylvania State University, a mine plan was developed for this site. This plan results in the layering of the alkaline and acidic spoil in order to achieve an overall net alkalinity in all spoil areas. Mining of this site should therefore not result in the formation of AMD.

Jan 1, 1994

By Y. Wang

Wet magnetic separation methods for recovering hematite and chromite fines and ultrafines are investigated in this paper. These methods include wet high intensity and high gradient magnetic separations, carrier or "piggy-back" magnetic method, magnetic field-induced aggregation and magnetic seeding. This investigation indicates that wet magnetic separation is more efficient for fines and ultrafines whereas other methods can be used to enhance the particle aggregation and/or the magnetic response. The magnetic behaviour of these minerals with respect to magnetizing field, particle size and temperature is also presented.

Jan 1, 1993

By D. Brunner

System simulation is an increasingly popular technique for analyzing and improving existing as well as newly designed underground mining operations. An engineering firm that specializes in simulation helped a major metals producer build a long-range planning model of an existing underground mine. Subsequently the team adapted this model to assess technology alternatives in the design of a new mine. The two models differ in the level of detail used for modeling the development process. This paper discusses the differences in approach between the models along with the experiences gained and challenges faced during the construction and use of the models.

Jan 1, 1999

By K. Lapakko

One responsibility of the Minnesota Department of Natural Resources is to encourage the development of mineral resources within the state. A second responsibility is to ensure that mineral development does not adversely impact other natural resources, including the water resources of the state. One approach the Division of Minerals has taken to fulfill these responsibilities is to conduct cooperative research with the mining industry. To encourage mineral development the Division has cooperated with industry on projects related to exploration, mining, and mineral processing. To examine environmental issues the Division has worked in concert with iron ore, base metal, and precious metal exploration and mining companies, as well as the Western Governors' Association, US Bureau of Mines, US Bureau of Land Management, and the US EPA for the past 20 years. These projects were conducted to evaluate methods of predicting, preventing, controlling, and treating problematic mine waste drainages, as well as mine waste revegetation. This paper I) briefly summarizes cooperative projects conducted, 2) enumerates elements which have contributed to the success of cooperative projects, and 3) describes changes implemented for future projects at the Division's new field and laboratory research facilities, as well as at existing mine and plant sites.

Jan 1, 1998