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By W. M. Merritts

A joint investigation by the Bureau of Mines and the Christopher Coal Co. at the Humphrey No. 7 mine, operating in the Pittsburgh coalbed in northern West Virginia, was undertaken to gain more insight concerning the hazardous emission of methane gas in mining, This report describes the equipment, procedure, and results. Horizontal bleeder holes drilled in the faces drained large quantities of methane, eliminating downtime of mining equipment. Also, larger quantities of methane were removed by forcing 14 to 25 g.p.m. water at 25 to 200 p.s.i. 5 pressure into the bleeder holes, In one infusion test a fluorescein dye was added to the infusion water; in later mining operations, the infusion water was traced for a distance of 1,500 feet. With vacuum pump applied to the horizontal hole the gas-flow rate increased, and the methane content decreased.

Jan 1, 1962

By Michael J. Beus

This Bureau of Mines report describes field investigations conducted in the Coeur d'Alene mining district of Idaho to obtain data on rock stress and physical properties. The resulting information has been utilized as input to detailed finite-element analyses to establish structural design criteria for deep-vein mine shafts. Measurement techniques include the Council for Scientific and Industrial Research biaxial and triaxial strain cells, the U.S. Geological Survey solid-inclusion probe, and the Colorado School of Mines dilatometer. Physical property testing was conducted in the laboratory on core obtained from each test site. Limited in situ physical property tests were also conducted. Reason-able success was obtained with the CSIR equipment, which was considered the most suitable for stress measurement in the study area. Test sites ranged in depth from 1,200 to 7,700 feet and are described in detail. The stress data were reduced by least-squares linear regression techniques to enable prediction of vertical and horizontal stresses to 7,500 feet. Ratios between the horizontal stresses as utilized for shaft design varied considerably, and a hydrostatic condition is the exception, based on Bureau measurements. Physical properties also varied widely, due to the complex geologic structure. Analyses of the data in terms of the tectonic history of the area show reasonable correlation. Data from previous rock mechanics investigations from the Coeur d'Alene district were also compiled and presented as part of this report to justify any generalizations regarding stress conditions and physical properties of the district as a whole.

Jan 1, 1980

By Edward W. Parker

(Toronto Meeting, July, 1907.) NOTE.-The material from which this paper has been prepared was collected for the U. S. Geological Survey Bulletin, Contributions to Economic Geology, 1906, and appears also, though in somewhat more extended form without illustrations, in that publication. ALTHOUGH the briquetting of coals and lignites has been carried on for many years in Europe, and has reached a particularly high state of development in France, Belgium, and Germany, it has made comparatively little progress in the United States. The causes for the backwardness of the United States in this regard are several, and first among them has been the abundant supply of cheap raw fuel with which the manufactured article has to compete. With our millions of acres of coal-productive territory, from which the product can in most cases be cheaply extracted, it has appeared in many districts more economical to waste the slack or culm, which con¬stitutes a considerable percentage -of the product, than to attempt to save it at the additional expense required for briquetting. It is for this reason that the view in all sections of the anthracite-region of Pennsylvania is marred by the unsightly culm-banks which encumber the ground, and that in some of the bituminous-districts one sees huge piles of unmarketable- slack allowed to burn up in order to get rid of them. When the coal is of a coking quality, or when the slack can be used for steaming-purposes, these losses are not sustained, but many thousands of tons of what might be converted into usable fuel have been wasted every year simply because of the increased expense involved in its preparation.

Sep 1, 1907

By Jon C. Yingling

Lean manufacturing, pioneered by Toyota, has been credited with the most significant improvements in production efficiency and product quality since the transformation from craft manufacturing to mass production in the early 20th century. It represents a comprehensive philosophy for structuring, operation, control, and management of production systems that is believed to have wide applicability. This paper outlines major lean manufacturing principles and discusses their potential for application in the mining industry.

Jan 1, 1999

By John P. Powell

The increasing demands for petroleum and its products and the steadily increasing cost of discovering and developing new oil fields are factors that emphasize the importance of increasing the recovery of oil from known petroleum reserves. Water flooding is a valuable conservation measure, not only preventing premature abandonment of stripper leases but also reviving interest in many areas previously abandoned. The use of water flooding as a means for recovering additional oil from partly depleted oil-bearing formations was first tried in Oklahoma in 1931. Early water-flooding operations were confined to the area of shallow Bartlesville-sand formations in Nowata and Rogers Counties, where many of the projects were outstandingly successful. The results of these operations stimulated activities in other pools in Oklahoma, and by the end of 1949 water flooding had been tried in 25 of the 49 oil-producing counties in the State (fig. 1). Approximately 33 million barrels of oil, or 1,806 barrels per acre, had been recovered by December 31, 1949, from 18,221 productive acres included in the 162 active and abandoned projects in Oklahoma by injection of approximately 449 million barrels of water.

Jan 1, 1951

By K. van Warmerdam, M. Pearson, C. Kember, D. McMullen, M. Thayer, C. Ugarenko

In July 2012, Hatch Ltd. and Air Products & Chemicals Inc. completed construction and commissioning of a 4000 tpd O2 cryogenic air separation unit (ASU) for Barrick Gold’s Pueblo Viejo Project located in central Dominican Republic. The ASU produces high pressure gaseous oxygen, which is used for the oxidation of refractory sulphide ore within the pressure oxidation (POX) circuit. As a result of the project’s remote location and tropical climate, many challenges were faced over the course of construction, commissioning and start-up of the ASU. These challenges included adequate preservation of equipment due to dusty and humid site conditions, final assembly and erection of the cryogenic distillation columns on site, limited spare parts inventory/availability, and an unfinished power source for plant commissioning. This paper discusses the steps taken by Hatch and Air Products to successfully design, construct, commission and start up the largest stand-alone ASU plant for a POX application in the metallurgical industry.

Jan 1, 2014

By C. H. Johnson

This paper on the out-and-fill method of mining is one of a series on mining methods published by the United States Bureau of Mines. It has been compiled chiefly from recent publications of the bureau describing in detail mining methods and costs at various mines. Other sources of information were the technical press, the Transactions of the American Institute of Mining and Metallurgical Engineers, the Mines Haudbook, and company reports. References other than those mentioned in Table 1, which lists the mines entering into this discussion and gives general data regarding them, are given in the body of the paper. The authors wish to acknowledge the kind assistance of many operating officials, either through correspondence or in the course of numerous visits to their mines. DEFINITION OF CUT-AND-FILL STOPING The out-and-fill method of stoping is that method in which relatively small sections or slices are taken successively from the lower surface of a block of ground by open-stoping methods, the broken ore being removed and each section filled with waste material before the next is mined. This definition excludes shrinkage stoping, even with subsequent filling; it excludes square-set and fill methods; it excludes the Mitchell slice method, which may be classed as underhand square-setting; it excludes the systematic use of stull sets and filling, which is a variation of square-setting; it excludes any method involving the caving of the ore, walls, or overburden during the process of extraction, although caving may be allowed to take place when the waste fill is withdrawn for use in other stopes; and it excludes any open-stope method without filling. Through variations, which will be discussed later, the cut-and-fill method merges into shrinkage stoping, open stoping, or square-setting. The use of casual timber support, such as props, stulls, or timber cribs for holding up weak portions of the back does not constitute a change from cut-and-fill to square-set mining.

Jan 1, 1933

By H. H. Schrenk

One phase of Bureau of Mines work in health and safety, is promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To insure that such devices will be available, the Bureau has established schedules of minimum requirements for self-contained breathing apparatus,3/ gas masks, supplied-air respirators (hose masks, air-line respirators, and abrasive blasting helmets, hoods, or masks),2 dispersoid (dust, fume, and mist) respirators, and nonemergency gas respirators (chemical cartridge respirators). Approval tests of self-contained breathing apparatus are conducted by the Safety Branch, approval tests of other types of respira- tory protective equipment are conducted by the Health Branch, These branches are in the Health and Safety Division.

Mar 1, 1948

On June 20, 1972, Ocean Energy was awarded Contract No. H0220055, entitled Portable Task Luminaire System Development. Initially, this was a 12 month program consisting of three phases: Phase I -- Design of the Luminaire System and Battery Chargers, Phase II -- Fabrication of Prototype Units, Phase III -- Fabrication of Production Prototype Units and Battery Chargers. In addition to developing the Portable Task Luminaire System, however, this contract was amended a number of times in the course of the program to include the development of a Low Coal Portable Task Luminaire, a Rib Mounted Luminaire System, and a Machine Mounted Luminaire System, all based upon the same high frequency fluorescent lighting and safety technologies involved in the Portable Task Luminaire. This report covers the activities of this program as amended, and includes the development and fabrication of all of the systems. This report constitutes the final fulfillment of the contract.

Jan 1, 1974

By M. G. Lipsett

One challenge in applying information technologies in Mining is building a business case. In Mine Maintenance, there is a complex flow of information that contributes to making informed business decisions. By understanding those information relationships and the cost of wrong decisions, analysts can estimate the value of information flow. Developers can then ensure that systems deliver key information in an accurate and timely way. In this paper, general maintenance decision-making is discussed, with examples of how model-based analysis can improve the information delivered to decision makers.

May 1, 2001

By M. Pearson, W. Bristowe, A. Hanson

"There's no such thing as quality assurance; only quality control ... by inspection. "(1) A common misunderstanding in the procurement and construction of custom designed, fabricated pressure vessels and piping systems is that quality assurance can be achieved by simply referencing codes, standards, ISO 9002, QMS or other such programs in the contract documents. In the authors' experience, nothing could be further from the truth, not detrimental to the performance of the equipment than the exclusion of inspection activities and reliance upon warranties and "fit-for-purpose" clauses. Likewise, the expectation that fabricators, suppliers, or third party inspectors can provide such assurances is also unrealistic where they have limited knowledge of the process, material selection criteria, or limited technical resources. The development and successful execution of a quality assurance program is a collaborative effort by engineers, designers, material suppliers, equipment fabricators, and field inspectors with the full understanding and support of the end user.This paper presents an outline of the quality control activities undertaken by the authors for several recently completed and on-going hydrometallurgical projects. The activities include: prequalification of fabricators and sub-vendors, shop audits, material validation testing, material source control and verification, positive material identification of weld metal overlay, specialised welding inspection, contamination control for titanium and titanium-clad fabrication, eddy current and mass spectrometer (helium) leak testing of shell-and-tube heat exchangers, hot cycle testing of titanium clad equipment, tolerance verification for refractory lined equipment, final inspection and cleaning.

Jan 1, 2004

By Russell G. Warncke

"This report is based primarily on a study of safety conditions and practices followed in the coal mines of Japan. Not all of the coal fields in Japan were studied, but typical mines in the largest producing areas and a fair cross section of coal-mine-safety conditions observed during February to April 1948 are described.Information was obtained through investigations conducted in the mines, discussions with mine-management officials and representatives of labor unions of the various mines visited, and examination of records and statistics from the various offices of the Coal Board of the Ministry of Commerce and Industry and from the Coal Association of Japan. Statistical data covering the same subject, obtained from different sources, varied in many respects and apparently were reported inaccurately, but such discrepancies can be attributed to different methods of reporting and compiling statistics.It is difficult to correlate the high fatal and nonfatal injury rates that prevail in Japanese coal mines with the conditions observed in the mines. Virtually all mines visited were attempting to prevent accidents and explosions, by apparently following known safety precautions for the prevention thereof. Some commendable safety innovations were observed at several mines; they indicated that mine officials are giving thought and consideration to hazardous conditions that affect their particular mines.Naturally, the operating officials and management were anxious to impress the writer with their interest in accident prevention and safety. Operating officials were found to be receptive to safety and wore interested in formulating definite safety programs. Some nines had well-planned and well-organized safety programs, which, if put into effect, would contribute greatly toward reduction of accidents.The approach to safety in Japan is quite different from that in the United States, especially the concept of personal responsibility for accidents and the extent to which the individual should be protected against hazards. Management is responsible for providing and maintaining safe working conditions. Collaboration between management and worker, as understood in the United States, does not exist in Japan.Increase in accidents since the cessation of hostilities is the result of unsettled economic conditions in the coal industry, influx of inexperience workers, and breakdown of discipline among the miners, who have been organized into unions. Those unions are greatly influenced by ""leftist"" tendencies.It was observed that the Japanese mine worker is fatalistic by nature and has little, if any, noticable safety consciousness. The most urgent major requirements to reduce accidents in the coal mines are to train the worker in accident prevention and instruct him regarding the inherent hazards of his occupation.Revision of the mining laws would help to reduce accidents if the companies would comply with such laws and provide safer working places and if the workers would cooperate with management and observe and comply with such laws as are enacted for their protection."

Dec 1, 1949

By D Teyhan, J Kirsch

Traditionally, most Australian iron ore mining operations have been surface-based. Processing plants were designed to handle dry ores. In recent years mining operations in the Pilbara have progressively moved below the water table exposing wet, sticky ores which have caused lost efficiency in screening operations as particles tend to agglomerate and adhere, blinding screening media. Miners and vibrating screen manufacturers have experimented with a shift from linear motion to elliptical motion screens. Elliptical motion conveys and lifts particles. Effective on flat deck (horizontal and inclined) or sloping decks it can be configured to provide a controlled transport rate, applying pressure in all directions to maximise screening efficiency. In practice, elliptical motion screens have proven to be effective in dislodging sticky particles from screening media, reducing blinding rates and improving screen efficiency. Moisture and clay content change during the life of a mine. These changes are sometimes the effect of seasonal rainfall, in other cases due to increased groundwater and clay content as mining operations go deeper. To compensate for such changes and optimise screen efficiency, changing the ‘shape’ of elliptical screen motion is required. This has traditionally required shutting down processing plants and making mechanical screen adjustments. Plant downtime is costly and machine adjustment has been a ‘trial and error’ practice. This paper will explore the results of a field trial that is currently underway in Brazil of a next generation elliptical motion screen design that allows operators to make changes to exciter rotational direction, speed and screen stroke angle, through electronic drive phase control. The machine’s electronic drive system synchronisation is enhanced for stability with a unique mechanical timing system. Operating at up to 6 g, screen adjustments can be made on the fly without stopping production. Early trial results are showing up to 50 per cent improvement in screen efficiency compared with traditional elliptical motion machines under certain feed conditions.

Aug 24, 2022

By R. J. Rotzinger

The Gibraltar Mine and Mill facility were commissioned in 1972 by Gibraltar Mines Ltd utilizing a flowsheet consisting of two stages of crushing followed by a rod mill / ball mill grinding circuit. During operations a number of opportunities were evaluated to expand the mill capacity; however, the economics of the day did not allow any of these projects to proceed. The mine continued to operate until late 1998 when it was shutdown and put on care and maintenance due to low commodity prices. Taseko Mines acquired Gibraltar in 1999 and in 2004, with the improvement in the metal markets, made the decision to restart operations. During the restart planning a number of opportunities for mill improvements and upgrades were identified and, after operations were successfully restarted, the decision was made to once again review expansion opportunities for Gibraltar. Taseko evaluated various expansion alternatives eventually deciding to install a SAG Mill, convert the existing rod mills to ball mills and distribute the SAG discharge to the resultant six 6 parallel ball mills. This paper discusses the design, implementation and commissioning of the SAG mill grinding circuit.

Jan 1, 2012

By Lloyd M. Kniffin

[This paper is one of series being prepared by the United States Bureau of Mines on mining methods, practices, and costs in the various mining districts of the United States. It describes the mine of the Hanover Bessemer Iron & Copper Co. at Fierro, Grant County, N. M., which is the only operating iron mine in the southwestern part of the United States. This mine is in a district noted for the great variety of ores that it produces. Within a small area, as shown is Figure 1, there are noteworthy deposits of nearly all the common metals. The ore occurs in lenticular masses dipping at about 50°. An underhand stoping method has been developed that requires but a very small amount of handling of ore. As the ore is very irregular in iron content and also in the distribution of the impurities--chiefly sulphur, silica, and magnesia--a method has to be used that will permit selective mining and will also allow ore and waste to be taken out separately as conditions change. A magnetic cobbing plant raises the grade of the ore shipped about 10 per cent.]

Jan 1, 1930

As we are all well aware, the demand for coal is increasing very rapidly. This makes the coal industry one of great opportunity for both the miner and the-supplier. Up until the middle 1960's, the price of coal had been one of the most stable of all commodities for the proceeding fifty years. In somewhat oversimplified terms this was because the inflationary tendencies had been offset by improved mine techniques and more efficient, more productive, and more reliable equipment; but, in the last seven years the price of coal has doubled. It is not the intent of this paper to discuss the many reasons for this price increase, but to show how the cost of hauling coal can be sharply decreased with a new truck concept. Not long ago a mining executive stated that all haulage trucks now available are basically the same. They look the same; they cost about the same; they have the same engine, power train, and tires; and, they have about the same operating cost. Truck size has increased which has reduced the number of drivers, but the purchase price and maintenance and repair costs have increased proportionally. Pits must be widened and loading shovels enlarged, out, all this has not reduced the cost of moving coal. Another executive said that he saw no advantage in buying new trucks because his people now know how to maintain and operate the ones they presently have. They have all the right spare parts along with a good maintenance program. Most replaceable parts of the trucks now in operation have been replaced and improved at least once and the trucks are now running better than when they were new. Besides, the trucks are no pretty well written off.

Jan 1, 1972

By F. Calizaya, M. G. Nelson

This paper presents a summary of basic requirements for the design, installation and operation of booster fans in coal mines, especially in deep and/or extensive mines. It includes a brief description of the major steps that should be followed to ensure that these units are used in coal mines safely and efficiently. The guidelines were prepared based on the standards and regulations adopted by two prominent coal mining countries, the best practices developed by the mining industry, and the applicable standards used in the United States for the fail-safe operation of main fans.

Jan 1, 2015

"1 INTRODUCTIONThe use of nondestructive testing (NDT) methods to evaluate the integrity of Augered Cast-in-Place (ACIP) and Drilled Displacement (DD) piles has been a subject of significant debate among engineers, contractors and NDT practitioners. This guideline document will illustrate the importance of reviewing all available information in conjunction with the NDT records. ACIP and DD piles have unique properties that must be considered when using a specific NDT method. Any evaluation of the integrity of an ACIP or DD pile must also include a thorough review of the detailed pile installation records and the site specific soil conditions. Long or theoretical descriptions of the methods have not been included in this publication. More detailed information about these NDT methods including their theoretical and historical backgrounds can be found in DFI’s Manual for Non Destructive Testing and Evaluation of Drilled Shafts (2004). Additional information can also be found in the more comprehensive textbook Nondestructive Testing of Deep Foundations by Hertlein and Davis (2006).1.1 PurposeThe intent of this guideline is to provide practical guidance for the proper interpretation of NDT results on ACIP and DD piles. Short descriptions of the main integrity methods available are provided along with several examples of how to use all of the information available to make sound engineering judgments about the results. This publication is a state-of-the-practice guideline to promote accurate engineering evaluations.For engineers inexperienced with NDT, these guidelines provide sufficient background information on NDT methods to help understand the limitations of the testing, assess the results presented to them, and formulate appropriate questions. This is particularly important for engineers charged with the responsibility to determine from those results what, if any, consequences there may be on the performance of the structure under construction."

Jan 1, 2016

By Girolamo Belardi, Silvia Serranti, Giuseppe Bonifazi, Roberta Palmieri

Ore textural and structural characterizations play a fundamental role in any preliminary study (i.e. comminution, classification, separation) addressed to the design and set up of beneficiation flow sheets. The possibility to utilise automatic tools able to perform a classification, and a quantitative description, of the mineralogical and petrographical characteristics of raw ore samples thus represents an important step to define, to control and to verify the entire set of parameters, ore-texture-related, that can affect the final beneficiation results. The procedure usually adopted is based on the analysis of polished sections and more in details the recognition of the different mineralogical species and associations and the measurements of some quantitative parameters estimating both the geometrical characteristics of each species and the possible spatial relationships between them. This approach, originally carried out by experts, utilising optical and/or electronic microscopy, was ‚replaced? during the years by more and more sophisticated devices integrating analytical facilities and acquired data processing. Such integrated analytical devices formed the breakthrough platforms into what is now known as modern Process Mineralogy. In this paper the possibilities offered by chemical imaging based devices and techniques, to perform ore minerals recognition/classification, and to perform their topological assessment, are presented. Tests have been carried out and are discussed in order to analyze the problems related to the development of suitable and low cost strategies addressed: i) to realize a full mapping of ore minerals/gangue inside selected samples, ii) to define the optimal data-flow handling to optimize the speed of processing versus the quality of the results and iii) to start to define logics and procedures finalized to implement innovative smart detection engines, chemical imaging based, for mineral processing addressed to perform both a preliminary characterization of the ore, at laboratory scale, and a further possible control of the different processed minerals flow streams.

Jan 1, 2014

By J. Paraszczak

Underground metal mining involves many challenges. Economic slowdown, tough international competition and sometimes volatile metal prices put constant pressure on mine operators to increase productivity and to reduce production cost. At the same time, countries such as Canada, the United States and Australia are experiencing skilled labor shortages that might even stall development of certain mine projects. Furthermore, some stages of underground production take place in particularly hazardous environments where the safety and health of miners is at risk. Automation of some processes in underground mining is one of the promising avenues to alleviate some of these problems. Loading and haulage are among the most critical operations and areas where implementation of autonomous vehicles has been targeted. However, although health and safety issues are a primary driver to opt for automation, the latter should ensure an acceptable level of productivity and pro?tability. With this in mind, this article focuses on the factors affecting operational effectiveness of autonomous underground loading and haulage equipment and the means to maximize it.