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By A. F. Colombo

Bench-scale research was undertaken to determine if adding ammonia to cyanide leaching solutions would enhance the extraction of copper from an argillaceous Michigan copper ore. Two leaching techniques, (1) rolling using a tumbling bottle and (2) aerating using a modified Buchner funnel, and variations in pulp temperature; were employed in evaluating the effect of ammonia concentration on copper extraction. Under these experimental conditions, the extraction of copper was shown to be independent of ammonia concentration and entirely dependent on cyanide concentration.

Jan 1, 1968

By F. N. Kissell

The machine-mounted continuous respirable dust monitor (MMCRDM) is a fixed-location area sampling device developed for possible use at the working face of an underground coal mine. This device, based on proprietary technology known as the tapered element oscillating microbalance, has evolved over the past eight years through a cooperative effort of the former Bureau of Mines, MSHA, and the Rupprecht & Patashnick Company in Albany, NY. The capability to measure respirable coal mine dust levels on a continuous basis, rather than depending solely on periodic samples obtained from the traditional coal mine dust samplers, has been a goal in the mining industry for nearly two decades. Recently, an extensive series of laboratory and underground tests was conducted by NIOSH with the cooperation of MSHA and coal operators to test the performance of the MMCRDM In preliminary laboratory testing, the MMCRDM seemed to work well. However, in every underground test, when compared to reference samplers placed close to the inlet, the MMCRDM failed to meet the 25% accuracy criterion specified in the contract under which it was developed. Two reasons explain this failure: First, in most tests the bias (the relative discrepancy between the average MMCRDM concentration and the average reference sampler concentration) was too great. Second, the variability of the samplers used for reference comparison was too large. Finally, the underground testing of the MMCRDMs showed that they are quite unreliable at this stage of development. In the majority of mine tests, no more than 10 shifts of data were taken before the MMCRDM failed to function properly. Major breakdowns, requiring the return of the MMCRDM to the factory for repairs, occurred on average every 28 days. To be considered mine-worthy, MMCRDM reliability must be substantially improved. KEYWORDS Dust, coal dust, dust instrumentation, dust sampling, dust monitoring, black lung, pneumoconiosis

By J Hall, A Gallardo, M Strizek

Mineralogy and coproponents Sino Iron, International Minerals and Austeel are in the process of developing four world class magnetite iron ore mines with multiple open pits along a 25 km strike length of Brockman Iron Formation to the south of Cape Preston on the West Pilbara coast. The close proximity of the proposed pits raises some challenging project approvals and environmental management issues relating to the impacts of dewatering at individual projects and the cumulative impacts of progressive development on local and regional groundwater resources, which includes a large fresh water aquifer system in the Fortescue River alluvium.This paper presents an outline of the hydro-environmental impact assessment process adopted and the key result that the cumulative impacts of dewatering at all four projects on the local brackish groundwater system in the basement rocks is only marginally more than the impact of any one project on its own, and that the impact on the Fortescue River alluvium aquifer is negligible. The paper also presents an outline of the proposed integrated water management approach that will involve coordinated monitoring, ongoing impact assessment and management, and reporting programs for all projects.

Jan 1, 2009

By M Pizey, M Kingsbury

Since 1950 Stockton Open Cast Mine has excavated over 60 million tonnes of Brunner Coal Measures overburden sandstones and mudstones. The current operator, Solid Energy New Zealand, recognises that acidic drainage from this overburden and from historic underground mines has led to depressed pH levels and elevated levels of metals in streams draining the Stockton Plateau. These streams report to the Ngakawau River. To quantify the effects of mine site acid drainage remediation/mitigation on the lower Ngakawau River water quality, a catchment hydrogeochemical model has been field calibrated and ecotoxicology tests have been undertaken. The hydrogeochemical model indicates that pre-mining and present pH values in the lower Ngakawau River are similar but present aluminium and iron concentrations are elevated. Ecotoxicology tests have semi-quantified the critical metal concentrations and interim water quality targets to achieve ecological recovery are presented. Analyses of long-term total suspended solids (TSS) and turbidity monitoring in the lower Ngakawau River and St Patrick's Stream indicate that TSS of 120 mg/L and turbidity of 20 NTU are exceeded for <20% per cent of the time. Hence, specific criteria to protect migratory native fish from turbid water are currently met in the Ngakawau River and St Patrick's Stream.

Jan 1, 2003

The unpaved road network on a surface mine is extensive, comprising numerous roads of varying construction and material qualities with highly variable traffic volumes. Existing haul road maintenance management systems (MMS) work well for predictable traffic volumes, but for complex mine road networks, the MMS becomes onerous. This results in sub-optimal road maintenance strategies with the attendant increase in total road-user costs and reduction in service. A real-time maintenance management system was thus sought to overcome the deficiencies of existing MMS for mine roads. Since most large mines operate trucks with on-board diagnostic data collation, linked through a centralized communication and GPS backbone, it was proposed that road condition could be monitored on a real-time basis through on-board vibration signature analysis. The aim of this paper is to present the development of a real-time mine haul road maintenance management system. Following are view of mine road maintenance practices, the real-time system architecture is introduced and the results of a field trial of on-board vibration signature assessment is presented. The trial results are discussed in the light of road defect signature recognition, analysis, signature repeatability and system limitations. This approach has applicability to other situations such as a network of district roads, subject to an analysis of the economic feasibility. The paper concludes that modern technology has the potential to apply maintenance as and where needed with possible reductions in authority cost and an improvement in service provided for the road user.

Jan 1, 2003

By Len Harris

Webster?s Dictionary describes culture as: ? The totality of socially transmitted behavior patterns, arts, beliefs, institutions and all other products of human work and thought typical of a population or community at a given time. ? A style of social and artistic expression peculiar to a class or society. ? Intellectual and artistic activity. ? The art of developing the social, moral and intellectual facilities through education. The authors have nearly 100 years of combined experience in the mining industry working with and consulting to mining companies and companies engaged in the supply of goods and services to the mining industry worldwide. In this report, they present their experiences and ideas on the importance of cultural aspects in the successful development and implementation of mining ventures. Their suggestions on how to handle culture shock will be of interest to expatriate managers, operators, social workers, and engineering and construction personnel posted to overseas operations, as well as to nationals posted to other parts of their own country.

Jan 1, 2008

By Adrian Rosen

When one thinks of innovation and leadership in wireless communications, one would rarely consider a potash mine to be leading the way. Agrium Incorporated has proven that they are leaders and innovators, as is evident in their recent deployment of a large-scale 802.11 wireless network in their underground potash mine located at Vanscoy, Saskatchewan. 802.11 is an IEEE standard for Wireless Local Area Network (WLAN) technology. Rather than simply replace an aging communications infrastructure, Agrium chose to let technology provide the framework for future success

May 1, 2006

By Russell J. Miller

A high-pressure intensifier system was designed, constructed and field tested as part of a program to determining the feasibility of applying high-pressure water jets on conventional mechanical rock excavation equipment to increase advance rates. Also developed were a high-volume swivel, capable of transferring the high-pressure water to a rotating cutterhead and manifold system for locating and protecting the jets on the cutterhead. Field tests were conducted in a granite quarry near Skykomish, WA, approximately 90 miles east of Seattle. The concept of improving excavation rates by using water jets to assist mechanical cutting was proven to be successful, with an average increase in excavation mete of 50 to 60%. For some tests, the excavation rate was more than doubled. Machine torque requirements were reduced approximately 25% when the water jets were used. It was suggested this was due to reduced cutterhead friction in the presence of the water jets. A comprehensive economic analysis was undertaken as part of a concurrent study to determine the degree of cost benefits attainable from increased advance rates. Very significant savings were seen to be possible. It was concluded that the basic concept of combining a water jet capability with a mechanical excavating machine is definitely possible.

Jan 1, 1976

General economic conditions continued to improve in the second quarter of 1984 as real gross national product advanced at an annual rate of 7.5 percent (table 1). This followed an even larger first quarter annual rate increase of 10.1 percent. The slower second quarter growth was greeted as a sign that the economy is not over-heating. The signs of slowed growth in some sectors suggest that the recovery may continue well into 1985 without the inflation symptomatic of a rapid recovery. Most of the slowdown in growth was absorbed by business inventories, personal consumption of durable goods, and residential fixed investment. Business inventories grew by only 68 percent as much as in the first quarter, personal consumption for durable goods grew by 58 percent of the first quarter rate, and residential fixed investment slowed to only 44 percent of the first quarter growth. Sectors with accelerated growth in the second quarter included personal consumption of nondurable goods and of services, which increased at annual rates of 9.6 percent and 3.8 percent, respectively, and Federal purchases of goods and services, which increased at an annual rate of 47.9 percent.

Jan 1, 1984

By R. D. Pehlke, J. V. Gluck

AS a portion of a general study of liquid-metal thermodynamics, high-temperature galvanic cells were used to study the effect of added dilute solutes on the activity of zinc in dilute solution with molten bismuth in the range 450° to 650°C. 1,2 The cells were of the type The experimental procedures have been described previously.1 In the course of studies conducted in the bismuth-rich corner of the systems Bi-Zn-Au and Bi-Zn-Cu, marked discontinuities were observed in the electromotive force-temperature relations for a number of the experimental compositions. Above the discontinuity temperatures, the relations, which were linear, exhibited slopes similar to the binary alloy of the same mole fraction zinc, as shown in Figs. I and 2. Below the discontinuity temperatures, the slopes were markedly different, but the relations remained linear. In general, as the amount of the third eletnent was increased, the slope of the lower portion of the relations tended to become less positive. The slopes of electromotive force-temperature relations reflect the entropy of mixing of zinc and, therefore, the occurrence of a discontinuity marks the transition between two different equilibrium situations involving the solution of zinc. A number of other investigators3-5 have used such observations to determine liquidus boundaries in binary alloys. Since the upper portions of the ternary electromotive force-temperature relations of this study had the same slopes as the binary alloys, the discontinuities are interpreted as marking the transition between the single-phase liquid region and the underlying two- and three-phase regions. Reference to the Zn-Bi equilibrium diagram6 confirms that the binary alloys were single-phase liquids at the experimental temperatures. Fig. I shows the electromotive force-temperature relations for the alloys containing Bi-Zn-Au and Fig. 2 shows similar relations for the Bi-Zn-Cu alloys. In the lower portion of each figure, the temperature of the discontinuity is plotted vs the mole fraction of the added solute at the various levels of zinc concentra- tion. Cross-plots from these curves at constant temperature permitted the construction of the partial liquidus surface isotherms shown in Figs. 3 and 4.

Jan 1, 1967

By D. M. Avant, A. J. Solomon, S. M. Pickering, W. R. Fox

Introduction Most high purity silica is produced from crystalline quartz, generally from sand. However, there is a small area of southern Illinois where a porous, friable white chert rock is found that is very different in physical form from quartz sand. This microcrystalline material, commonly referred to as tripoli, is more easily ground to micron sizes than sand. Although of similar Moh's hardness, microcrystalline tripoli is less abrasive than either ground quartz sand or many synthetic abrasives. Location The southwestern corner of Illinois is underlain by extensive deposits of very porous chert; in some places the material is quite white. Two companies, Illinois Minerals Co. and Tammsco Inc., mine and process this white material. The Illinois Minerals plant is located at Elco, and the Tammsco plant is in Tamms, IL. Both companies mine from various locations within a 10-mile truck haul of their plants. Production from this district has been continuous since at least 1915. Malvern Minerals Co. mines and processes a generally similar microcrystalline, friable novaculite near Hot Springs, AR. Geology The southern Illinois white tripoli area is on the southern flank of the Illinois Basin. The commercial silica zone is a facies of the Clear Creek chert of Lower Devonian Age. To the north, where it occurs deep in the basin, the Clear Creek is a siliceous limestone. In the mining area, thin overburden has allowed access by surface ground water, which has leached away the carbonate content and left a quite pure silica residue. Fossils characteristic of sea bottom deposition, such as brachiopods and trilobites, are occasionally encountered in mining. The structure of the mining area is poorly known, due to infrequent outcrops. Strata in most mines are inclined at dips of 5° to 20°. There appear to be occasional high angle normal and reverse faults, but these are seldom of any significance in mining. The friable white silica zone mined in the Clear Creek chert is overlain by dark brownish-red chert and siliceous shale. Exploration drilling to date has not encountered the base of the microcrystalline tripolitic zone. Chemical content Leaching by ground water solution has removed virtually all the carbonate from the original siliceous limestone. Impurities encountered are red to yellow iron oxides, aluminous clays, and occasional black manganese oxides. The silica has no detectable formula water. A typical chemical analysis and physical properties are listed in Tables 1 and 2. Mineralogy and crystallinity Southern Illinois friable tripoli appears amorphous under the polarizing microscope. No crystal structure and only occasional, vague, patchy anisotropism is evident. However, the material gives an excellent quartz X-ray diffraction pattern. Thus, so far as X-ray mineralogy is concerned, the material is clearly

Jan 12, 1986

By Thierry Bernard

For many years now electronic initiation has brought the time parameter to the centre of blast designs forever. Although this parameter existed before the era of electronic detonators, Blasting engineers or blasters could not directly handle it; technology imposed it. Only discrete values were available. Today, the fact that we can choose any detonation time for an explosive charge questions the viability of most of the rules applied for blast design. Thus, the very famous charge per delay method, that enables a level of vibration to be forecast at a given distance (“Chapot’s law”), is no longer necessarily valid when using electronic initiation. Therefore, it must be approached in a totally different manner. The KUZ-RAM formula, that allows fragmentation to be forecast, is also subject to the same distortion. The aim of this article is to show how the calculation laws used for blast design are influenced by the time parameter (sequence) and how we can efficiently make the most of this, in particular for vibrations. Copyright ©

Jan 1, 2005

By V. R. Spironello

The Bureau of Mines is involved in research directed toward the conserva¬tion of important raw materials and the utilization of solid waste. Two of the objectives are to conserve high-quality coking coals used for foundry coke and to utilize waste materials of marginal quality but of high calorific value. These objectives are consistent with Bureau goals. Pilot plant cupola trials were made to evaluate the adequacy of various alternative fuels, and to determine to what extent they could replace the foundry coke in cupola charges. Information was obtained on furnace performance, metal and slag chemistry, environmental questions, and the properties of castings. It was shown that anthracite or bituminous coals can partially replace charge coke up to the 40 pet level. Briquetted materials prepared from fuel fines, and waste prod¬ucts or byproducts of high calorific value, all tend to break down on heating in a cupola so that their use must be restricted to below 20 pet replacement. In cases where pitch-bonded coal fines or petroleum coke were used, carbon pickup by the iron was inadequate for gray iron specifications. Although emphasis during this work was placed on basic slag practice, some acid practice results are included.

Jan 1, 1980

By Ralph Harris, Xia Qi, Frank Komsic

"Gold cyanidation kinetics which are often limited in commercial operations by the rate of oxygen dissolution from gas bubbles into the slurry, are discussed. Emerging technologies for improving the rate of oxygen dissolution are compared and the gas efficiency, energy use and operating performance of inverted cones and a device based on a jet diffuser are examined. The effect of solids loading is also reviewed and a relationship between operating parameters and the kilograms oxygen dissolved per kilowatt-hour is presented.Inverted cones are shown to create slurry settling problems at high gas flow rates and surface tension lowering agents are shown not to greatly improve the overall rates of oxygen dissolution.The novel jet diffuser technology operates at a range of gas to liquid ratios that improves its energy use over conventional technology and the performance of a number of designs are discussed.Gas efficiencies as high as 35% were observed with the novel diffusers at 40 cm diffuser immersion and are expected to increase at greater immersions. Energy use of 1.8 kg 02 I kWh were estimated for prototype full size diffusers operating at 100 cm immersion. Energy use of 3.S kg 02 /kWh is conservatively expected at 600 cm immersion.IntroductionGold ExtractionGold that can not be recovered by gravity separation can be recovered by either the Merrill-Crow process or the newer carbon in pulp (CIP) or carbon in leach (CIL) processes 1. Reductions in operating costs and improvements in gold recovery are central mill operating strategies. The present paper examines the potential for improvement that can be achieved in the gold cyanidation step of gold recovery. This paper introduces a number of emerging technologies and provides a basis for comparison of the performance. It shows that the basis for comparison of a particular technology depends on the type of gold extraction circuit employed and the type of reactants employed."

Jan 1, 1996

By Hanns J. Billmayer

Optimized Operator Compartment layouts based on previous Bureau of Mines activities in standardization and optimization of controls were designed and installed in three operating vehicles. Two National Mine Service 48A-36 TorKars were modified in production prior to delivery to the Quarto Mining Company. An Elkhorn AR-4 scoop owned by Adanac Coal Company was modified in a local rebuild shop. The modified vehicles were then evaluated underground under normal production conditions for a 60 day period. Vehicle operators and management appear well satisfied with the compartment modifications.

Jan 1, 1976

By Jhon Melo

Los “softwares de aplicación” como herramientas en la exploración geológica, generan importante información geográfica sobre el área a estudiar, así como la cartografía y la toma de muestras en laboratorio. En ese sentido, el presente texto señala el manejo adecuado de dichas herramientas a través del uso de una base de datos, donde existe una estructura basada en el software (VISUAL FOXPRO, PARADOX, etc) y asi ejecutarla mediante una aplicación gráfica que permita tener una representación de lo estudiado como ocurre en un muestreo geoquímico.

May 25, 1998

By L. M. Lowe, D. G. Feasby, J. R. Goode

"Rare earth resources usually contain minor amounts of radioactive elements. The most widely recognised sources of radioactivity are associated with thorium and uranium. However, also present in the resources are isotopes of rare earth elements (REE) that are themselves radioactive, including lanthanum (La-138), lutetium (Lu-176) and samarium (Sm-147). These radioisotopes, as well as remnants of the natural thorium (Th-232) and uranium (U-238, U-235) decay series, can contribute to significant levels of radioactivity in mixed REE concentrates and in separated products. Levels such as these can present challenges for transport, transboundary movement, product storage, workers’ health and safety, as well as waste management issues at the facilities that separate out the individual REE’s. These are discussed in this paper. A particularly challenging radioactive isotope is Ac-227 (a decay product in the U-235 decay series). Actinium behaves chemically similar to lanthanides and hence normally concentrates with REE multi-element composites. Reliable analysis of Ac-227 is not widely available and the methodology required to deal with this challenge is briefly described. A principle reason for minimization of radioactive content throughout REE processing is restrictive specifications by concentrate purchasers in order to reduce waste management challenges. Approaches to the minimization of radioisotope content in REE concentrates and separated products are outlined in this paper."

Jan 1, 2014

CONTENTSIntroductionGeneral GeologyCoral Reef-Volcanic Set'iesRock TypesMicaceous Sandstone and MudstoneLimestoneVolcanic RocksChertsDepositionDiatremesEarth MovementsRelation of Ore Bodies to StructureINTRODUCTIONThe author encountered the problems discussed in this paper in 1947 while surveying the mining centres of Mungana and Redcap for Broken Hill South Ltd. After his resignation from that company he made a semi-regional survey to investigate the regional problems raised by the preliminary study. Broken Hill South Ltd. continued its studies on the known ore bodies while the author's investigation was going on, and he is indebted to the staff of this company for assistance during his field work.The area mapped is part of a larger area mapped in reconnaissance by the Aerial, Geological and Geophysical Survey of Northern Australia by a party headed by Dr. H. I. Jensen...

Jan 1, 1952

Australia is the world's leading producer and exporter of mineral sands. Despite increased production from some other countries in recent years, Australia maintained its No.1 position in 1988 among world producers of mineral sands concentrates. Production of the titanium minerals -- ruffle, ilmenite and leucoxene, as well as synthetic ruffle -- by the seven companies currently comprising the Australian industry increased in 1988 in response to continuing strong demand for feedstock by the pigment industry. Production of co-product zircon remained at the 1987 level, reflecting declining zircon grades. Exports of mineral sands concentrates increased in 1988; export earnings exceeded $300million. Prices for mineral sands concentrates are now at a historical high and, assuming that the world economy remains strong, real prices should continue to trend upwards in the short term. Exploration in the Eneabba-Cooljarloo region and the Scott River area, both in WA, the Murray Basin, Vic, and the central Queensland coast area, has identified substantial resources of heavy mineral sands. These discoveries have reversed the trend of the early 1980s of falling resources of mineral sands. In 1988, BMR estimated that economic demonstrated resources (EDR) of ilmenite, rutile, zircon and monazite combined was about 72.8 million tonnes. However, a substantial portion of the resources on the east coast are frozen as a result of environmental considerations. The proportion of mineral sands concentrates processed in Australia increased with the commissioning of two new synthetic rutile plants; Australia is now the world's leading producer of synthetic rutile (total capacity 272000 tonnes), most of it for export. Australia's two TiO2 pigment producers have both increased capacity, lifting national capacity by some 70p ercent to over 120000 tonnes/yr. As part of the expansion one producer converted from the sulphate to the chloride process. Other new pigment plants are being proposed for the future.

Jan 1, 1989

By J. Greg Sanchez

The New South Ferry Terminal in the New York City Transit system represents an important milestone for the city. This is the first station designed and built in the 21st century. The design of the fire safety system included relying on Computational Fluid Dynamics to analyze the dispersion of heat and smoke, and modelling of people egress to determine the egress requirements. The project also looked into how to protect the structure from the heat exposure in order to meet the fire rating requirements. This paper provides an overview of the fire safety design approach taken to design the new South Ferry Terminal station in lower Manhattan and looks into fire modelling, structural fire protection, and station evacuation.

Jan 1, 2008