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By R. G. Dressler

The design and operation of the Koppers powdered-coal gasifier and its auxiliaries at Louisiana, Mo., are described. This unit was designed to convert 1 ton of coal per hour with oxygen and superheated steam into synthesis gas - primarily carbon monoxide and hydrogen. The first run was made on May 4, 1949. After this, 44 short runs (less than 8 hours each) and 1 long run (lasting 11 days) were made. Total gasification time was 420 hours. The gasifier was not cooled down during the year when these runs were made. After an initial period of test operations and equipment proving, during which 12 runs were made, the effect of numerous variables on gasifier performance was studied. The long run was made primarily to check the equipment in sustained operation. Detailed data from these runs are presented.

Jan 1, 1954

By CLARENCE WM. POY

THE most common difficulty faced by an engineer or mine operator when opening a new property in a new field is the lack of roads and of cheap transportation. This one item often swings the balance of success or failure in starting a project. In Alaska, as elsewhere, such problems are more or less serious. In the boom days around the Valdez district, as well as in other parts of this territory, freighting was accom¬plished by dog teams or horses, or even by men that were willing to put their shoulders into harness, because there were virtually no roads. More important, there was only one time when supplies could be transported, and that was when there was suffi¬cient snow on the ground following a heavy wind. Then, and only then, could one depend on the snow to support horses and sleighs, and be sure that the gulleys, streams, and crevices in the glaciers were filled with snow to avoid pitfalls. These methods were used when one had no roads, no streams in the summer to float a barge, or even a trail for a pack train. If the snow was deep and soft, trans

Jan 1, 1935

This report is a compilation of all information obtained in accordance with the requirements of contracts S0122076 and H0232056. A series of eight coal mines were visited to determine their communications usage and requirements. Presently available equipment was surveyed and evaluated to determine its applicability to the needs of the mines. The equipment studied includes that made by the following companies: Anaconda Telecommunications Division Andrew Antenna Bendix Communications Division Collins Radio Group of Rockwell International Executone Communication and Sound Systems Gai-tronics Mine Safety Appliances Company Motorola Communications and Electronics, Inc National Mine Service Company Plessey Communications Systems Corp Pye Electronics Limited Reach Electronics Set Com Corporation Sonex Incorporated

Jan 1, 1974

By A. B. Kinzel

SINCE the exposition of the behavior of certain iron alloys by Sykes1 involving the existence of an austenite loop and the discovery of such a loop in the chrome iron system by Bain,2 there has been much conjecture both on his part and on the part of metallurgists in general as to the exact shape and location of this loop. In previous work commercial steel has been used and the microscope has been employed to locate the critical points so that the position of the loop has been quite approximate. Numerous attempts have been made to measure the critical points of the carbon-free alloys but all of these for one reason or another have failed. A satisfactory method for studying these phenomena, is presented here. MATERIAL The first difficulty in this study was to obtain pure chromium-iron alloys. This has been overcome by melting in a vacuum electrolytic iron and chromium analyzing 99.84 Cr, Fe and C. A pure magnesite crucible was used and the melt allowed to solidify in the crucible. A typical analysis is chromium, 10.10 per cent., carbon, 0.006 per cent., silicon and manganese nil. To overcome the problem presented by segregation, ingots were made into wire 0.04 in. in diameter. This was accomplished by hand-forging the ingots into rods, using an oxyhydrogen flame for heating, in order to avoid carbon. Subsequently the rods were swaged too wire, the heating being carried out in hydrogen. Thus local segregation was eliminated although differences in analysis between portions 50 ft. apart were noted. An electric-resistance method was first tried to determine the critical points, but due to the physical defects in the wire this failed. Bain had previously shown the presence or absence of critical points in a qualitative way by observing the sag in a catenary. The author has devised the following method which gives an accurate determination of the critical points from expansion-temperature curves of suspended wire, a special telescopic dilatometer being used for the purpose.

Jan 1, 1928

Pese a tener cajas sólidas en su estructura, algunas vetas desarrollan un relleno frágil, ocasionando problemas futuros de sostenimiento para el "corte y relleno" de los mismos. Por ello, se utilizó el método de los "Square Sets", donde además de ser costoso, implicaba eliminar una proporción de la roca encajonante y diluía el contenido metálico de los filones. En ese sentido, el objetivo del texto es señalar la viabilidad del "método Cornish"como método alternativo, económico, de rendimiento óptimo y que no presenta riesgos para el personal o la labor realizada. Este método es aplicable en aquellas vetas uniformes no falladas, que tengan desde una potencia pequeña hasta aquella que sea posible apuntalar, así como en aquellas que requieran sostenimiento del techo en la veta mima o donde se realizen Shrinkages. El proceso del método se basa en la preparación de los tajeos, luego en la explotación(perforación y disparos), enmaderado, relleno del tajeo, recuperación de madera, las variantes en la preparación del tajeo y la recuperación del mineral. La única desventaja que ofrece este método es su peligrosidad, dado que si se aplica en zonas inadecuadas o sin la supervisión que garantice el cumplimiento de las normas preventivas, es preferible el uso de los "Square Sets". Sin embargo, la aplicación del método resulta mucho más productiva en rendimiento teórico puesto que alcanza de 7 a 10 toneladas por tarea de 8 horas y responde satisfactoriamente siempre y cuando las condiciones de las vetas lo permita.

Jul 20, 1957

By W. C. Phalen

During the search for deposits of soluble potash salts in the United States, carried on by the United States Geological Survey, much infor- mation was collected on the salt resources and industry of the United States. The more important features of the information thus gath- ered, compiled, and digested may be classified under five headings, as follows: 1. Geology of the salt deposits of the United States. 2. Theories relating to the origin and formation of salt deposits. 3. Chemical composition of saline materials in the United States, principally rock salt and natural and artificial brines. 4. Statistics of salt production in the United States. 5. Technology of salt production. The first four items are not discussed in this report, but their treatment will comprise a separate report published by the Geologi- cal Survey, which will supplement this report, relating to salt- making processes, and will describe comprehensively the salt resources of the United States. Persons desiring a copy of that report should apply to the Director of the United States Geological Survey, Wash- ington, D. C. In addition to the discussion of processes, this report gives a brief description of the more important sources of salt in the United States. This description has been abstracted from the much length- ier description contained in the report to be published by the Geo- logical Survey.

Jan 1, 1917

By John V. Beall

GOING west from Denver on Route 6, the direct road to Grand Junction, one gets the first glimpse of mining a few miles east of Denver near Idaho Springs where the workings of defunct gold mines are visible on the sides of mountains along the highway. One enterprising company is turning a profit by showing tourists through the mine and mill and then selling them gold samples on the way out. We have always known that mining people are ingenious, but this proves it. About five and a half hours fast driving west from Denver brings one to Rifle, Colo., which is the site of the oil shale mine, retorting plant, and refinery of the U. S. Bureau of Mines. As you drive up to the mine, you can see a portal high on the face of the cliff in front of you where the mine surface plant literally hangs by its toenails. Below, the retorting plant and refinery gleam in the sunlight. Up at the mine, Fred Wright will show you how the oil shale is extracted in two benches (a third bench would be used for commercial mining) by the room-and-pillar method. In mining the top level, an underground crew of thirteen men have been able to produce 1500 tons of shale in each eight-hour shift. To do this, the mine is thoroughly mechanized. The mining method is de- scribed in the September issue of Mining Engineering.

Jan 1, 1949

By Jennifer Riefenberg

Research efforts by the U.S. Bureau of Mines include running a series of displacement-discontinuity, boundary-element models to simulate the gateroad design at an underground coal mine in northwestern Colorado. The initial mine design is a yield-abutment chain pillar arrangement in a three-entry, longwall gateroad system. Pressure effects from mining the first and second panel were recorded using borehole pressure cells (BPCs). These field data were then compared directly to the model output. Observed yielding in the field was approximated by reducing material property values and/or removing pillar elements in the model. Model results using this calibration technique mirrored the field measurements consistently. Using the calibrated model parameters, a suite of models was run simulating an experimental entry design: exchanging the yield and abutment pillar locations. These model results reflect a 20¬to 33-percent reduction in core stresses in the yield pillar during mining of the second panel. Improved pillar and entry conditions are suggested by these predictive results. The design modifications were then implemented at the mine along a 150-m (500-ft) test section. Field observations and measurements from the experimental design test site compared favorably with trends of the model predictions.

Jan 1, 1993

By AIME AIME

MOST recently elected to the limited group of Honorary Members in the A.I.M.E. is the distinguished Australian metallurgist, Guillaume Daniel Delprat. His citation reads: "in recognition of his distinguished achievement as metallurgist, engineer, and administrator in the production of ferrous and nonferrous metals," Mr. Delprat's ability and experience in both the ferrous and nonferrous fields at once distinguishes him from most of his professional brothers. Mr. Delprat's nativity was neither Australian nor English, for he was born in Delft, Holland, in 1856, and educated in Amsterdam. At the age of 22 he went to Spain, as metallurgist for the Tharsis Sulphur and Copper Co., Ltd. Afterwards he spent some time with the Bede Metal and Chemical Co., which had mines in both Spain and Norway, and of which company he became general manager. Other positions of responsibility held by Mr. Delprat before he went to Australia included the managing directorship of the Cordova Exploration Co., with properties in Spain and Canada; of the Rincon Silver-Lead Mining Co., in Spain; and of the Deloro Gold Mines, in Canada.

Jan 1, 1936

By W. G. Freeman

This study provides recommendations for improved safety in underground blasting procedures based on in-mine observations of blasting practices in 30 underground metal, non-metal, and coal mines, and the analysis of blasting accidents since 1970 and existing state and federal regulations pertaining to the storage and use of explosives. Results of these analyses and observations indicate that 1) blasting accidents have declined but are an important contributor to the hazards of underground mining; 2) existing regulations are essentially adequate; 3) greater emphases should be placed on human errors and unsafe practices and the enforcement of existing regulations; and 4) future revisions of these regulations and standards should be organized, and their intent coordinated to eliminate ambiguities.

Jan 1, 1980

The original manuscript of section 2 of this series of miners' circulars devoted to accident prevention in bituminous-coal mines was completed in September 1944. At that time roof bolting had been tried with some success in the lead-mining district of south-eastern Missouri, but information on the subject was so fragmentary that it was not included as a method of roof support. References to roof support in bituminous-coal mines, therefore, were confined almost entirely to conventional timbering methods. In 1947 the Bureau instituted a research program and intensive study of the general problem of roof control, which emphasized roof-bolt application. The rapid increase in mechanized mining following the close of World War II provided the impetus for the Bureau's roof-control investigations, because the vertical supports used with conventional timber restricted the maneuverability of mechanical face equipment, and the industry wanted to explore every possible method of eliminating interference with the production cycle to gain full advantage of mechanized mining. Moreover, the accidental dislodgment of vertical supports greatly increased the roof-fall hazard. As roof falls have killed and seriously injured more mine workmen every year than any other cause or classification of injury since records have been kept, the Bureau assumed this investigative leadership with the prime objective of substantially reducing the annual toll from falls of roof, including falls of rib and face.

Jan 1, 1958

By Brendan Demich, Joseph McGuire, Emily J. Haas

Near misses recorded and reported by workers can provide awarenessto the potential causes of injury and prompt safety management initiatives. Although most companies require near-miss reporting, it is unclear what the value of these reports are, if any, and how they influence subsequent actions or controls to reduce on-the-job risks. Researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a case study with an aggregates company in which near-miss reports were analyzed at each of their locations over an entire quarter during the summer of 2018. Within that quarter, workers recorded 249 near misses. Of those, 167 were valid near misses that occurred at work. Researchers coded the reports using a qualitative 5 × 5 risk matrix. Of the 167 near misses, 19% were deemed low risk, 25% moderate risk, 30% high risk, and 26% critical risk. Several patterns in the near-miss incidents were documented, including classification of incidents and common corrective actions referenced (i.e., elimination/substitution, engineering control or redesign, work process/procedures, and personal protective equipment). The analysis provides insight into ways that risk communication and management programs can be improved to reengage workers and their situational awareness on the job.

By H. A. Thorne

This paper describing the mining practices at the Chino mines at Santa Rita, Grant County, N. Mex., is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The Nevada Consolidated Copper Co., Chino mine's, operates an open-cut copper mine at Santa Rita, Central mining district, Grant County, N. Mex. This mine is located about 16 miles east and slightly north of Silver City, the county seat. The ore is-transported in standard railroad cars by the Atchison, Topeka & Santa Fe Railway Co., approximately 10 miles to Hurley where it is milled. The concentrated are shipped approximately l'70 miles over the same railroad to the smelter of the American Smelting and Refining Co., at El Paso, Tex. (fig. 1)

Jan 1, 1931

By N. T. Lowe

This Bureau of Mines publication presents salient deposit information in abstract form on 119 principal mineral deposits in the State of Nevada. Commodity coverage addresses 17 critical and strategic commodities that appear to have commercial production potential in the State. The core of the deposits described is taken from those properties evaluated d under the Bureau of Mines Minerals Availability Program (MAP); additional deposits are included to provide a more complete coverage. Institutional and infrastructural factors affecting mineral development are also discussed.

Jan 1, 1985

The accompanying supply/demand flow diagrams and 10-year tables for mineral and fuel commodities present essential data required by government, industry, and others to formulate policies and programs that can help assure an adequate and continuing supply of mineral raw materials. The 10-year data base terminates with 1973 figures because adequate world information was not available beyond that date. Moreover, 1974 was an anomalous year with respect to prices, supply, and demand for many commodities. The selected mineral supply/demand tables and flow diagrams comprise but one "output" from the massive body of "information and data collected and com-piled by the Bureau of Mines on a continuing basis covering mineral production consumption, prices, shipments, imports, exports, and stocks, as well as industry activities in all States and abroad.

Jan 1, 1975

By C. Vipulanandan, M. Dawood, Dongmei Pan

"With the aging infrastructure, there is a need to maintain and extend the service life of steel structures in general and steel piles in particular. Steel piles support not only vertical loads but also dynamic horizontal loads in onshore and offshore applications. In order to select the appropriate methods to repair corroded steel piles used in onshore and offshore application, corrosion mechanisms were investigated with the rate of corrosion in various environments. The corrosion rate of steel in soil, water and soil-water interface varied from 2 to 500 µm/year. Based on literature review and analyses, the repair methods can be broadly characterized as protective coating, electro-chemical methods, wrapping and encasement and partial replacement of steel. Also, methods to evaluate the repair materials and the repair configuration have been documented.IntroductionOne of the biggest challenges facing the aging infrastructure is the materials loss and deterioration due to corrosion. Many studies indicate that in the US alone, costs due to corrosion loss is more than $276 billion annually (Michiel et al., 2010). Corrosion is the major cause of deterioration of steel structures and components (MNC, 2005). Load bearing steel piles are used as foundations for various types of structures and hence corrosion is very much influenced by the environment such as soil, water and soil-water interface. Corrosion of steel pile foundations may result in reduced capacity in the axial and lateral directions. Hence, understanding the rate of pile corrosion is essential to select the appropriate repair methods to avoid excessive deflection and failure (Decker et al. 2008).To prevent the deterioration mechanisms that attack a pile, it is fundamental both to identify and understand the deterioration mechanism that has been the cause of damage. Understanding the deterioration mechanism allows the engineer to design a repair that will combat this type of damage. It is widely recognized that the corrosion of carbon steel in soil, water and soil-water interface proceeds according to the following simplified anodic reaction and cathodic reactions in the presence of oxygen (Decker et al. 2008)."

Jan 1, 2017

By Bengt H. Fellenius

It is a truism that in the design of pile foundations one must consider both capacity and settlement. As to capacity, most basic text books contain simple methods of design of capacity of single pile. More sophisticated methods are the subject of many journal papers. However, methods for design considering settlement of pile foundations are scarce. (Most confuse settlement with the movement due to load-transfer?the transfer of load from the pile to the soil). Furthermore, for both capacity and settlement, most methods include several simplifying assumptions regarding soil layering and neglect the effect of the frequently occurring fill and excavations, as well as changes of the groundwater table and pore pressure distribution. Therefore, the methods may provide qualitative results, but not quantitative. Because of this situation, pile design often appears as somewhat of a guessing game and a very subjective?and risky?occupation. This need not be. Pile foundation design is controlled by three factors: capacity, strength, and settlement requirements and these have been combined in a method called "the unified design of piles and pile groups considering capacity, settlement, and negative skin friction" (Fellenius, 1984; 1989), which method is summarized in this guide.

Jan 1, 1991

By G B. Smith, D Hillier, T Gibbons, D B. Donato, M D. Adams, S Davies, R S. Schulz

Responsible management of cyanide solutions and tailings on gold processing plants worldwide is an important aspect to these operations and is regulated via guidelines provided by the International Cyanide Management Code, an industry initiative designed to minimise cyanide risk to operators and the environment. Here we demonstrate the unprecedented causal relationships surrounding the saline (>14 000 mg/L total dissolved solids - TDS) and hypersaline (>50 000 mg/L TDS) cyanide solutions in gold plant tailings in the Central Goldfields of Western Australia, resulting in zero wildlife mortalities on three sites over the study period of almost one year. Wildlife interaction and ingestion is significantly lower than that experienced at other gold mine sites, with more rapid degradation of weak-acid dissociable (WAD) cyanide within the tailings storage facility (TSF). A rigorous chemical sampling using a novel æminimal accessÆ robotic sampler device and wildlife observation exercise was carried out at two hypersaline mine sites: Barrick Kanowna Belle (BKB) and Gold Fields St Ives (GSI) and one saline site, Barrick Granny Smith (BGS). The data was compared with available reported chemical sampling and wildlife observation data from a previously operational fresh water site (<2000 mg/L TDS) that had experienced wildlife mortalities, Case Study D (CSD). The comprehensive body of work, along with cyanide degradation test work carried out in the laboratory, was analysed via hypothesis development and testing, causation analysis and dynamic chemical modelling. The non-mortality effect on these sites appears to hold over a further four years of routine wildlife and cyanide monitoring by site personnel. This study has helped these three mine sites achieve and maintain full Compliance Cyanide Code status over a significant period while removing the need for operating the detoxification plants they would otherwise have required.CITATION:Adams, M D, Donato, D B, Schulz, R S, Smith, G B, Gibbons, T, Davies, S and Hillier, D, 2013. Hypersaline-induced reduction in cyanide ecotoxicity at gold operations, thereby obviating detoxification plants, in Proceedings World Gold 2013, pp 489-502 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Carl Lee

CHICAGO in the last week of June fulfilled all its promises to the visiting engineers except one. This holds true with respect to the activities of the Regional Meeting of the A. I. M. E. in particular and of Engineers' Week in general. No one expected to find much of the beautiful in the outward aspects of the Fair-the Century of Progress Exposition, to be more formal; but they expected novelty, color, and startling lighting effects at night, and they were in no sense disappointed. It has been said that the architecture is a portent of the style of the buildings of the future; most who have seen the Fair hope that this forecast will prove inaccurate. As to the exhibits themselves, they are splendid. They are in keeping with the theme of the Exposition-a Century of Progress in science, in engineering, in the industries based upon them. No attempt will be made here even to suggest the exhibits that are most interesting. There are plenty for every one; and any member of the Institute who has the opportunity should by all means visit Chicago before the end of October.

Jan 1, 1933

By Frank E. Williams

This Bureau of Mines report deals with the urbanization of Tucson, Ariz., a southwestern city with an arid environment. Zoning regulations concerning known aggregate sources are described, and information relating to projected needs for the urban area is furnished. History of growth is outlined not only for the local aggregate industry, but also for the entire urban area. Past conditions are pointed out and background material for future conditions is provided.

Jan 1, 1967