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Jan 1, 1885

CYRIL STANLEY SMITH, Chairman CARL E. SWARTZ, Past-Chairman ARTHUR PHILLIPS, Vice-Chairman E. E. SCHUMACHER, Vice-Chairman H. A. MALONEY, Treasurer FRANK. T. SISCO, Secretary 9 West 39th Street, New York, N. 1. Executive Committee 1944 1945 WILLIAM C. ELLIS C. S. BARRETT ALAN MORRIS T. A. WRIGHT KENT R. VAN HORN L. L. WYMAN

Jan 1, 1943

By I. H. Warren, Forward F. A

The reduction of aqueous slurries of uranyl carbonate at elevated temperature with compressed hydrogen m the presence of metal catalysts and certain organic promoters has been shown. to yield uranium dioxide. The reduction takes place in a sequence of steps. The purity and sintering properties of the dioxide make it of interest as a starting material for fuel element production. Simple control can be exercised over the surface area and oxygen/uranium ratio of the product during reduction. URANIUM dioxide for fueling atomic power reactors 1s conventionally produced as a powder by simultaneously decomposing and reducing ammonium diuranate with hydrogen in a furnace at high temperature. Fuel elements are then generally made from this powder by compacting and sintering ( 1). In order that elements approaching theoretical density may be obtained,

Jan 1, 1961

By Eung Ha Cho, Wendi Li

Wet desulfurization of Pittsburgh No. 8 coal and Illinois No. 6 coal were conducted with sodium hypochlorite in the laboratory. Pittsburgh No. 8 coal was leached by hypochlorite at high pHs in one step only. The hypochlorite concentration varied from 0.2 to 0.6 molar; sodium hydroxide concentration, from 0.2 to 0.8 molar; and temperature was at the levels of 80 and 90°C. The desulfurization of Illinois No. 6 coal was conducted in three consecutive steps of pretreatment in concentrated ammonia at room temperature, leaching with hypochlorite at room temperature and hydrolysis in sodium hydroxide solution at 90°C. In the leaching step, hypochlorite concentration varied from 0.2 to 0.8 molar. The desulfurization method of Pittsburgh No. 8 coal was found to reduce mainly pyritic sulfur. More than 70% of pyritic sulfur removal was achieved at the optimum conditions of 0.4 molar hypochlorite, 0.4 molar sodium hydroxide and 90°C. The desulfurization method for Illinois No. 6 coal was capable of reducing significant amounts of organic sulfur. The removal of organic sulfur achieved a 37.8% reduction at the optimum operation of leaching at 0.4 molar hypochlorite and room temperature followed by hydrolysis at 0.3 molar sodium hydroxide and 90°C. The chlorine content in the coal produced by the chlorination during leaching was kept below the threshold value of 0.3% at the optimum conditions of the desulfurization method for each coal.

Jan 1, 2005

Mine drainage and mine reclamation are topics of major interest to the mining industry, federal and local governments, and the general public. This publication and its companion three volumes are the proceedings of a conference held in Pittsburgh, Pennsylvania, April 24-29, 1994. There were twelve sessions (69 papers) that dealt with mine drainage, including modeling, geochemistry, prediction, treatment, control strategies, characterization, hydrology, and case studies. These sessions comprise volumes 1 and 2. The six sessions (34 papers) that dealt with reclamation and revegetation of disturbed lands are included in volume 3. Volume 4 includes the six sessions (34 papers) that dealt with such topical issues as fires at abandoned mine sites, subsidence, hydrology, mine wastes, and policy. Poster session presentations are represented by 49 papers and 92 abstracts that have been placed in the back of volumes 2, 3, and 4, consistent with the subject of that volume.

Jan 1, 1994

By A C. Chieregati, A Heberle, F L. S P Villanova

Since the publications of Gy’s initial work, many authors have discussed the approaches to estimate the variance of the fundamental sampling error (FSE). Experimental tests suggested by Pitard and François-Bongarçon determine the sampling parameters K and a to calibrate Gy’s formula. The heterogeneity test and the sample tree method are well known and broadly used for many commodities. However, prior to the analysis, the collection of a representative sample is an intriguingly difficult task. The composite for the heterogeneity tests often consists of run-?of-?mine material or processed ore on a conveyor belt. In most cases the final sample does not have enough mass, mixes different geological units, represents a rare blend and does not characterise the deposit. In order to obtain a reliable composite for trace elements and low-grade ores, sampling practitioners suggest at least half a ton of material.To prevent the common representative pitfalls in the FSE, this case study focuses on a single gold-?bearing geological unit collected in situ. With this unit being structured by the mine geologists, but with the interaction between engineers and chemists, it was possible to validate the reconciliation suggested by Pitard (2015). The heterogeneity test and the sample tree method were performed using 500 kg of a smoky quartz from a single geological domain and the results were compared to Gy’s formula. The logging practice by the geologists was modified, emphasising the definition of the size of the gold nugget or its cluster, number of grains and association. Finally, a mineralogical study was conducted on the geological unit to define the liberation factor. All the information is compiled in this paper, showing the need to fully understand the mineralisation to correctly define representative samples and proper analytical techniques.CITATION:Villanova, F L S P, Heberle, A and Chieregati, A C, 2017. Heterogeneity tests and core logging – a final reconciliation, in Proceedings Eighth World Conference on Sampling and Blending , pp 107–114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Nirander M. Safaya

Revegetation success on surface mined lands is dependent upon the nature of the plant growth media. Soil physical and chemical properties dictate the needs for specific reclamation and subsequent management practices. Field experiments were conducted at six coal mine sites in Oliver and Mercer Counties, North Dakota to determine the subsequent effects of a single application of selected amendments on spoil and topsoils over the five year period, 1974-1978. Considerable variations in the physical and chemical properties were found in mine spoils from site to site. The texture of spoils ranged from sandy clay loamy at North Beulah I to loamy at Glenharold, and from sandy loamy at North Beulah 3 and South Beulah sites to loamy sands at the Center site. The pH of the sites ranged from 6.5 at South Beulah to 8.2 at North Beulah 3. In many cases, the pH values of mine spoils were not significantly different from the topsoils. The electrical conductivity (ECe) did not exceed 6 mmhos cm-1 at the test sites even though in other studies much higher values were recorded in the same vicinity. The spoils from Glenharold and North Beulah test sites can be classed as moderately saline, and those from Center and South Beulah as non-saline. The sodium adsorption ratios (SAR) varied from less than 1 to 32, with highest values in the spoils of North Beulah 3 followed by Glenharold; all other sites were nonsodic. Lowest SAR values (less than 1) were found in the topsoiled sites at South Beulah and Center. Spoils of North Beulah 3 test site were highly calcareous, followed by North Beulah 2 and Glenharold. Center mine spoils which were the least calcareous of the test sites, showed the calcium carbonate equivalent three times higher than that of the topsoil. The average calcium concentrations in the spoils of North Beulah 3 and South Beulah test sites were -13 and 14 me 100g -l while at North Beulah 2 and Glenharold test sites 25 and 22 me 100-1-1 were recorded, respectively. The overall magnesium concentrations ranged from an average of 4 to 16 me 100g 1. Sodium concentrations in all sites never exceeded 10 me 100g-1. Phosphorus concentrations on the average at North Beulah 1, North Beulah 2, and Center were 10.2, 4.6, and 22.2 µg g -1 spoil, respectively. Concentrations of potassium ranged from 200 ppm at South Beulah site to more than 375 pp in at the Glenharold site. High concentrations of sulfates (239-2778 µg g-1) seem to contribute to the salinity in these spoils. Chloride concentrations of spoils were low and never exceeded 40 µg g-1 spoil. Based on established critical levels of deficiency for micronutrients in agricultural soils, it seems that none of these were deficient. However, controlled environment experiments did reveal increased plant growth responses when some micronutrients were added to the mine spoils. Treatment effects were highly site specific depending on the nature of the soil/spoil characteristics and, of course, the properties of the various treatments. While slack coal amendment to the spoils at North Beulah 2 site affected significant increases in a large number of variables (both major and trace elements), amendment of the topsoils at the South Beulah test site with leonardite resulted in significant decreases in a number of variables, particularly trace elements. Spoils at Glenharold and North Beulah 3 demonstrated the fewest significant changes due to amendments. Calcium, magnesium, strontium, organic matter and nitrogen were consistently increased from site to site with the addition of lignitic materials. Other spoil/topsoil physical and chemical properties (30 variables) as affected by amendments and time are discussed.

Jan 1, 1982

By A. D. McMahon

Changes in world mine and smelter supply sources of zinc have led to changes in zinc supply patterns in the United States during the past 3 years, 1970-72. The result has been a growing reliance on foreign sources of zinc metal to furnish an ever-increasing portion of expending domestic requirements. This review of fundamentals and historical developments is intended to provide background in order to place the future of the U.S. zinc industry fn perspective. The properties and uses of zinc are described. A new study on U.S. reserves is presented with description by geographical region and comparisons with older reserve data. The technology of the zinc industry from prospecting through refining is described with emphasis on the metallurgy involved in the various methods of smelting. Production, consumption, and imports are discussed and illustrated with graphs and tables to review the past and present patterns. Government actions affecting the industry are shown.

Jan 1, 1974

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By M J. Shearer

An investigation into the reliability of the data being collected at the Mount Isa Mines site operated by Glencore in Queensland allowed on-site ventilation personnel to scrutinise pressure and volume measurements collected from the primary surface fans. The investigation effectively identified discrepancies being reported to the on-site remote monitoring system. The difference between the real-time and static measurements on the P63 RAR shaft identified that the in situ differential pressure transducer and piezo annubar system was not operating correctly. This indicated a deficiency of approximately 30 per cent reporting back to the remote monitoring software versus the live readings measured with the Pitot tube bomb and ALNOR AXD610 pressure micro-manometer.Constant monitoring of an operations ventilation network is imperative to ensuring that the underground atmosphere provides a safe and healthy workplace. Further benefits to real-time monitoring allows for the early indication of network failures and promotes increased availability. An innovative approach to out engineer and improve the existing measuring equipment from the 1970s was sought.The use of ultrasonics in the mining industry is not new with ventilation management systems (VMS) equipment available within the marketplace. The introduction and implementation of a reliable product for real-time monitoring was a challenge to overcome due to limited access and suitable measuring points within the mine. The available equipment on the market through mainstream suppliers was not suitable for the unique application required due to the in situ installation of the surface fans. A solution was identified in the oil and gas industry through collaboration and innovative thinking. This paper describes the sustainable approach to implement a reliable air flow monitoring system on-site.CITATION:Shearer, M J, 2017. Case study – an analysis of reliability and efficiency: ultrasonic versus annubar technologies, in Proceedings Australian Mine Vent Conference 2017, pp 51–56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Everton Azola de Mattos

Na operação da Anglo American localizada em Barro Alto, utiliza-se 2 (dois) Fornos Rotativos no processo de fabricação de ferroníquel. Esses fornos possuem 6,2m de diâmetro e 185m de comprimento, no qual é necessário o monitoramento de temperatura (20) e vazão (4) ao longo do forno. Originalmente essas medições eram realizadas através de 2 PLC’s embarcados nos fornos, no qual recebiam as medições via cabos em bandejamentos. Esses PLC’s se comunicavam via rádio modem com os PLC’s principais dos Fornos. Durante a operação encontramos diversas dificuldades de manutenção e confiabilidade, já que os fornos operam em regime de 24h por dia e 7 dias por semana. Por várias vezes alguns cabos se danificavam devida a alta temperatura dos fornos, as bandejas que se desprendiam, falhas de cartões dos PLC’s, etc. Com isso as medições eram interrompidas. Para solucionar esse problema, foi desenvolvido um sistema de Instrumentação Wireless. Esse sistema basicamente é a instalação de instrumentos com a tecnologia WirelessHart no qual os instrumentos não possuem alimentação por cabos e sim por baterias e a comunicação é feita via sinal wireless. Esses instrumentos apresentam alta confiabilidade nas medições no qual foi possível retirar toda a infraestrutura antiga e garantir continuidade/confiabilidade nas medições.

Oct 30, 2017

By Fernando Cillóniz

Benchmarking es un proceso de comparación y medición de los procesos de negocio de una organización, con aquellos que lideran el mercado. De forma que se obtiene información para mejorar el desempeño de las empresas. En ese sentido, el presente texto señala la utlidad del Benchmarking en las empresas donde el uso de la Internet y las tecnologías de la información permiten hacer más eficiente las comparaciones e intercambio de experiencias y conocimientos, así como internacionalizar el proceso.

Aug 25, 2002

By B. Wilshire, P. W. Davis

It has been shown that grain-boundary migration during high-temperature creep can reduce or even prevent the formation of intercrystalline voids, giving a considerable increase in ductility.' A similar observation has been made in a recent investigation of the creep properties of various grades of nickel and nickel alloys. The results can be illustrated by the observations made on: a) Pure vacuum-cast nickel (99.993 pct Ni) b) Impure vacuum-cast nickel (99.97 pct Ni) c) Pure nickel containing internal voids (produced by a process of intering). d) A substitutional solid solution alloy of pure nickel containing 1.16 pct Sn. All the materials were given a high-temperature anneal (>850°C) to produce a stable grain size of 7 to 10 grains per linear mm. The apparatus and techniques used to obtain the present results have been described elsewhere.' In this series, grain growth was observed only in the highest-purity, vacuum-cast metal. Thus we may consider that in the other materials grain-boundary migration was prevented by either preexisting voids or solute atoms. The effect of migration on the creep ductility of the above materials can be seen from Fig. 1, which

Jan 1, 1962

Tonnage and grade are the principal reported components of mineral resource estimates but tonnage is a derivative of two more fundamental estimates; volume and bulk density. Typically, most of the effort in a resource estimation study is directed towards grade and volume, yet poor application of bulk density data to resource models can result in significant biases. The impact on tonnage estimates is easily recognised but poor density estimates may also introduce subtle biases into the grade estimates. Methods for measuring bulk density have been discussed previously. This paper focuses on the manipulation of bulk density data and the extension of bulk density from essentially point measurements to block estimates within resource models. Bulk density is a continuous, geologically controlled, spatial variable and should be treated as such. Issues such as combining data from multiple sources, sample support and the interdependence of bulk density and grade estimates must be resolved. The statistical and geostatistical techniques used for grade estimation are, under the right circumstances, equally applicable to bulk density. The importance of bulk density needs to be recognised. With robust raw data and correct estimation procedures, better estimates of bulk density can be obtained and both local and global tonnage and grade estimates can be improved.

Jan 1, 2000

By A R. Bye

Energy comes at great cost to our world and societies and therefore we should use it wisely and optimally. Societal pressure is enforcing this and the industry must respond by being proactive.The mine-to-mill approach to integrated mine and semi-autogenous grinding (SAG) mill optimisation demonstrated that throughput gains of up to 20 per cent could be obtained through a closer match of blasted run-of-mine ore to the feed best treated by a SAG mill. Since that approach was developed, new drivers have risen to prominence including environmental costs and impact of energy, water, waste. This is set against a backdrop of reducing ore grade and increasing demand that is pushing up our impact on the environment. The new challenges demand new approaches.This paper explores the opportunities in taking traditional approaches to optimisation to new levels of two-way integration and incorporating potentials for ore upgrade into circuit design. The new mantra may be æflexible circuitsÆ û designing and building for the present and the future by allowing for the uptake of new and future technology.

Jan 1, 2009

By R. E. J. Putman

Rising demand, artificial market conditions, increased overseas competition, and a fluctuating international situation have brought ever increasing pressures to bear on the nonferrous metals industries, and particularly in the United States, Although capacity is being expanded by the construction of new plants and the development of new ore deposits, increasing attention is being focused on the possibilities of improving the performance of the existing installations and of getting the most out of the new equipment now installed. At first sight the task appears formidable. Based on raw materials which are nonhomogeneous, and possessing characteristics which are hard to quantify, even the processes by which the values in the ores are concentrated and extracted are in many cases not fully understood. The necessary analytical equipment and transducers demanded by these industries have also been slow in development and their earlier absence has hampered the application of modern control technology, This is reflected in plants which have been designed for ease of manual rather than automatic control, and in which the application of control techniques at first sight appears economically prohibitive. However, in any industry progress often comes only in small steps, It may be that by the wise choice of limited objectives and perhaps only partial solutions, substantial improvements in plant performance can be implemented now, and with only a modest investment. If modern control equipment is chosen of the type which can be reprogrammed, advantage can be taken later of more sophisticated solutions as the technology of the industry advances. This task of improving plant performance can and must be commenced even though our knowledge is incomplete. The experience of a related mineral consuming industry, with similar problems in the past, can be encouraging.

Jan 1, 1967

By Eric E. Cather

A mineral survey of the Fisher Gulch RARE II area (A5299), Trinity County, California was conducted by the U.S. Bureau of Mines and U.S. Geological Survey. The Bureau of Mines was responsible for detailed examination of mines, prospects, and mineralized zones; the Geological Survey conducted geological, geochemical, and geophysical studies of the area. The area is underlain by the Salmon Hornblende Schist. Tonalite stocks 1.5 mi (2.8 km) to the east and northeast of the area intrude the schist and are closely associated with the nearby nines (Cox, 1967). The mines have quartz veins containing sulfides and gold in shears trending east to north past in the schist and tonalite (Hotz, 1972). Strewn and terrace gravel s occupy most of the drainages, many have yielded substantial quantities of gold.

Jan 1, 1981

By Antonio Adel dos Santos

Visando elucidar o comportamento da carepa terciária durante a laminação de tiras a quente, em um aço produzido como laminado a quente e com rigorosa exigência de qualidade superficial, foi realizada uma parada forçada do laminador, impondo-se, imediatamente, um resfriamento rápido da superfície da tira. Amostras coletadas na região do arco de contato mostraram que a carepa possui espessura na faixa de 10 ?m a 14 ?m na entrada das cadeiras, sendo reduzida para 7 ?m com a deformação, sem ocorrência de ruptura. Tais características indicam que, do ponto de vista do comportamento no trem acabador, a carepa apresenta espessura e plasticidade adequadas para evitar defeitos nos produtos laminados. A carepa foi constituída predominantemente por Fe3O4, óxido plástico na temperatura de laminação. Foi desenvolvido e aplicado um modelo de crescimento da carepa, que forneceu valores de espessura muito próximos dos medidos, se tornando uma ferramenta útil para análise da influência de condições de processo na carepa.

Oct 30, 2017

By John C. LaScola

The Bureau of Mines investigated coal storage silos to determine how gassy coal must be for methane accumulations in a silo to become hazardous and where such accumulations are likely to occur. Methane concentrations were measured in the open space above the stored coal pile, in the pile, and in the reclaiming area. No methane layering was found in closed-top silos. Reclaiming areas were as gassy as the top part of the silos. Coal samples were collected from the conveyors entering the silos in order to assess the gassiness of the coal. No simple correlation was found between the gassiness of the coal stored and the measured methane concentrations. However, at mines where the average 24-hour gas emission from the conveyor belt samples was 14 ft3/ton or more, fans or open tops were used. It appears that a large fraction of the methane released during storage remains in the void space between the coal particles.

Jan 1, 1980

By James R. Boyle

The mining methods and practices used at the Young zinc mine, American Zinc Co. of Tennessee, have resulted in a low-cost, high-yield operation. Zinc ore (sphalerite) occurs in limestone-dolomite beds of the Kingsport Formation and is mined by modified room and pillar method. Utilizing trackless mining equipment which incorporates a high degree of flexibility, this operation has had a steady increase in productivity.

Jan 1, 1965