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This report summarizes the work performed by the Bureau of Mines on the development of analytical procedures for determining metallic and interstitial impurities in high-purity tungsten. Fourteen published methods and seven unpublished methods are briefly described. Carbon, hydrogen, nitrogen, and oxygen, in microgram to higher quantity levels, can be determined by several methods. Trace levels of 29 metallic impurity elements can be determined by optical spectrography, X-ray spectrography, and other instrumental methods.

Jan 1, 1968

Develop a means for analyzing seismic crosshole data to predict and monitor the Flow of leach solution during in situ mining. Background Improvements in predicting and monitoring in situ leach solution flow would aid in planning well field configurations. These improvements would also facilitate permit application by assuring regulatory agencies that leach solution would not escape from a well field undetected. Seismic tomography can detect fractured zones, which enables the prediction of probable flow paths, and it is a promising technique for monitoring leach solution injected above the water table. Tomographic analysis of crosshole seismic data provides a two-dimensional picture of the distribution of seismic velocities between the transmitter and receiver boreholes. The positions of fractured zones and of leach solution can then be inferred from the seismic velocities.

Jan 1, 1989

By Roberts T. J, Thomson I. A

Mill scale, which contains a high proportion of magnetite and wustite, was added to the feed to the Whyalla grate kiln pellet plant during the production of acid pellets for domestic consumption. Its addition resulted in increased production -rates together with reduced consumptions of bentonite, fireclay and fuel. Mill scale was particularly beneficial when treating feed containing difficult to process, earthy, high ignition loss iron ores. Test work in the laboratory and subsequent plant experience showed that the magnetite and wustite oxidised in the drying and preheat sections of the travelling grate. The additional heat reduced gas flows through the grate kiln system, aided the drying of green balls containing earthy ores and increased the preheat strength of the balls. These advantages were offset to some extent by higher power consumptions to grind the harder mill scale and process difficulties caused by the contamination of mill scale with oil and coke.

Jan 1, 1974

By Rafael A. Rivera

"Since the dawn of construction, there has been a need for excavations, which sometimes need to occur below the groundwater table. Excavations in themselves are difficult enough, with the myriad of requirements, such as engineered support of excavations, considerations for stability and numerous other concerns. Excavations executed in rural landscapes can be accomplished easily without significant consideration to accessibility, adjacent properties or structures, and construction limits and deformations. However, all of these factors can have an impact on excavation considerations in an urban landscape. When digging below the groundwater table, these conditions, along with concerns associated with groundwater drawdown requirements, discharge limitations, groundwater contamination, property limits, adjacent buildings and subsidence concerns, can lead an experienced dewatering contractor to consider diverse installation methodology and equipment to allow construction to occur below the groundwater table.534 W. 29th St. New York, N.Y.There are many things that must be considered when constructing a new high-rise building within a small property footprint measuring 25 ft (7.6 m) wide by 80 ft (24.4 m) in length. When you take into account that the foundation needs to go several feet below the groundwater table and that there are two existing multistory buildings with shallower foundations on either side of the proposed structure, this task now becomes much more difficult. Consideration of geology, groundwater levels, depths of excavation and shoring for the excavation becomes critical to the success of the project. On a regular basis, dewatering contractors confront similar situations in congested cities where available real estate is limited.To minimize the negative impacts of construction dewatering, it is important to mitigate the potential effects of construction dewatering to the surrounding buildings, sidewalks, underground structures, tunnels, subways and other existing infrastructure. Such an instance occurred at the project located at 534 W. 29 St. in New York City. On this particular project, the required drawdown was greater than the typical 15 ft (4.6 m) of suction lift, so a vacuumed can pump system was utilized. The tubing was connected to a vacuumed perimeter dewatering well-point system, which is a predrainage system that is installed prior to the start of excavation for the underpinning of the adjacent structures and for the overall foundation. Each well-point, which was composed of a PVC pipe that was 1.5 in (38 mm) in diameter by 25 ft (7.6 m) long, was drilled to a depth of about 23 ft (7 m) using a hollow stem auger and was installed around the perimeter at a centerto- center spacing of about 7.67 ft (2.3 m). In lieu of a traditional perimeter collection header, and to allow for greater flexibility for the contractor, the well-points were interconnected to a modified vacuum can pump system utilizing ¾ in (19 mm) drop tubes that were “spaghetti” around the perimeter."

Jan 1, 2017

By E. R. Kaiser

ACTIVITY on long-range and on immediate wartime problems shared the attention of specialists in coal research during 1943. Programs of the principal coal laboratories were more adequately financed than in previous years, but all reported shortages of technical personnel. Expansion in coal research in the year to come will depend primarily on the availability of qualified research talent.

Jan 1, 1944

By Samuel H. Dolbear

NOT WITHSTANDING the extremely low ebb of business activity, the nonmetallic industries have fared somewhat better than some other branches of mining. The average price level in nonmetallics, although far from satisfactory, has resisted any cataclysmic fall such as has been suffered by copper and other metals. Stocks, also, though too abundant, represent no corresponding overhang of the market, which should result, in some branches, in a more rapid recovery. Research work has continued in some industries with interesting developments.

Jan 1, 1933

By Louis Ware

BEFORE the war we often heard the term "Big Business." And there were complaints of the ills and abuses attributed to bigness in business. Although there were examples where the small businessmen spoke for their rights and sought protection from the bigger ones, it has only been in recent war years that a tendency has developed definitely to divide the business of our nation into the big and the small. In some cases, those with an eye to the political value of the vastly greater number of small businessmen of the country have fomented this division by hurrying to the protection of these more numerous voters, and intentionally or not have emphasized in their writings and verbal attacks any and all differences of these interests that could either be found or fabricated to, suit the occasion. It has become another example of breaking the people into classes and thus setting up the basis for the claims of one class against another, and the subsequent demand for legislation and Governmental aid. The terms "big" and "small" are purely relative. One businessman, employing a hundred men, told me recently he did not know which adjective would be more appropriately applied to his operation. He did not know whether he should join the small operators' group that had been organized, or should consider himself big. He said that his present plant seemed big to him when he looked back to its humble beginning many years ago with a couple of men in two rooms. Yet, when compared with many of his competitors who employ thousands, his was small. He did add, however, that he probably became big one day a few years ago when the union moved in and organized his employees.

Jan 1, 1945

By M Safa

Addressing deficiencies and defects that occur during construction projects is costly and time consuming. The manual quality assurance programs currently used in the industry have certain limitations, including human error and lack of consistency. Hence, there is a need for integrated electronic models that employ new technologies and methods. This research introduces an integrated construction quality control system that has the potential to improve quality management processes in the construction field for piping construction, which is a complex process often requiring rework. The proposed integrated system relies on data collected from construction sites using photogrammetry and laser scanning, which is then used to compare actual work performed to that designed. The proposed system aims to improve the promptness and accuracy of quality assurance processes, in particular dimension measurements, by avoiding human error and integrating defect detection and quality management. The use of this system has highlighted some of the limitations during data fusion and acquisition process, which are highlighted in this paper. These aspects must be considered to increase the reliability of the acquired information.

Aug 1, 2013

By Dziurzyn&apos, W. ski

This article outlines the results of a computer simulation reproducing the transport of a mixture of air and methane following the outburst on 25 November, 2005 in transport gallery D-6, bed 409/4, at the ?Zofiówka? hard coal mine. Based on a mathematical model, numerical method and boundary conditions from the disturbance caused by the outburst, the Ventgraph system of computer simulation programs was adopted for the study. We performed a computer simulation of the influence exerted by the outburst on the propagation of the air and methane mixture, and compared the results of this simulation with those of the actual event as registered by sensors of the mine monitoring system. A validation of the model allowed us to present temporal changes in the concentration of methane and air along flow routes. Keywords: mine ventilation, outburst of methane, numerical simulation, monitoring system.

Jan 1, 2008

By R. J. Gochin, G. D. Schena, R. Spencer

The impact of a mineral project in a developing country is evaluated in the broad context of its economy using input-output models. Minimum economic theory is used to develop simple numerical models. Sets of technical coefficients are exploited in the development of linear models of the productive element of an economy. The analysis allows assessment of the overall economic consequences of a mineral development in which issues broader in scope than financial objectives need to be incorporated in the evaluation. In part 1, the framework for the development of the input-output model is presented. The model is refined to incorporate country-specific behaviour. The increased flexibility of the enhanced semi-input-output model permits a more confident investigation of the economy-wide effects associated with a new project in the mineral sector of a developing country. The relevance of the models is illustrated using an example from Namibia

Sep 1, 1991

By John A. Dunn

The history of underground coal mining has developed through the years from a manual digging and loading process to the highly mechanized pro- cess that it is today through the use of electric power. Mine power systems have closely followed the continued pattern of improvement and mechanization, through necessity and the application of technological advances, At the beginning electric power used in coal mines was confined to haulage. Since d-c power was better suited to traction drives, mine power systems naturally developed using direct current. During this development, a number of street railway systems were in service, using 550 volts, and it was natural that mine trolley systems went in at 550 volts. As machines for mining operations developed and the number of operating mines increased, a safety hazard developed through the use of 550 volts. Most regulating agencies opposed the use of 550 volts, and after a time the maximum voltage permitted was limited to 300 volts hot line to ground. Up until this time most mines had operated with one central generating station, which served utilization power to the whole mine. Power demands were not very great and transmission losses were within reasonable limits.

Jan 1, 1964

By E. P. Youngman

The mining laws referred to by those who furnished the reports mentioned in the preceding paragraph are : General Austrian Mining Law of 1854 and the Law of 1868 , which prescribes for Hungary (as well as for Transylvania ) the full text and decisions of the General Austrian Mining Law; Government Decree 18346 , 1859 ; Parliamentary Decree of 1861 ; the Law of 1871 ; the Commercial Code , Law 37 of 1875 ; the Industrial Lar of 1884 ; the Law of 1386 ; the Decree of the High Court of Justice , 5540 , of 1399 ; Laws 6 and 7 of 1911 ; Law of 1921 ; Laws 23 and 24 of 1922 ; Laws 5 and 21 of 1927 ; and Law 40 of 1928. ( Lev 21 of 1927 and Law 40 of 1928 are labor laws . ) A compilation of the mining laws of Hungary , " Magyar Banya Jog , " or the " Hungarian Mining Law, " was made use of in part . This volume is the second edition of a school textbook , which ras prepared by Dr. Bela Balkay and Dr. Imre Szeoke , and which was published by the Apollo Press ( V. , Sas -utca 13 , Budapest ) in 1909 .

Jun 1, 1931

The U.S. Bureau of Mines conducted a laboratory study to determine what effect use of water-jet-assisted cutting has on frictional-ignition suppression. A single bit with a steel tip, installed on a rotating drum, repeatedly made 22-in-long cuts in a block of Berea sandstone. The drum was operated in an enclosure that contained an explosive methane-air mixture. High-pressure front-mounted water jets operating at 2,000 to 5,000 psig and low-pressure rear-mounted sprays operating at 80 psig were used; the number of ignitions that occurred with each type of spray was compared. The rear-mounted spray was more effective for preventing frictional ignitions than the front-mounted water jet.

Jan 1, 1989

By H. J. Garcia

Biodegradation of cyanide by microorganisms isolated from solids previously exposed to cyanide has been investigated. Initial sodium cyanide concentration was 300 ppm at pH 10.5. The kinetics of biodegradation were found to be first order with respect to cyanide concentration, and the overall reaction rate constant is k = 0.102 day-1. The activation energy and the frequency factor were determined to be { A }Ea = 5.45 Kcal/mol and A = 1.28 x 10-2 sec-1, respectively. Based on these values, thermodynamic properties of an intermediate activated complex were assessed. All tests resulted in cyanide concentrations less than 0.1 ppm in about 35 days at 250C, whereas at 350C the time of biodegradation to reach this cyanide level was 30 days. Kinetic data were also established to relate biodegradation to amount of inoculum. The maximum theoretically-attainable rate, Vm , and the optimum amount of inoculum, K , were determined to be 4.8 x 10-4 M NaCN/day and 7.5 % of amount of inoculum. With respect to the mechanism of biodegradation, cyanide was shown to decompose to carbonate, bicarbonate and ammonia. Titrimetric analyses revealed concentrations of 5.6 x 10-3, 4.8 x 10-3 M, and 70.2 ppm for carbonate, bicarbonate and ammonia, respectively. The average cell population was determined to be 3.75 x 108 cells/mL.

Jan 1, 1994

By D. Duvris

The main objective of this work was to quantitatively investigate exhaust emission levels, as related to maintenance (service) intervals, during the operation of diesel-powered equipment at an underground bauxite mine in Greece. Such emissions depend on a great number of parameters, including the type (technology) and tuning of the engine, the type of work performed as related to the engine workload, suggested maintenance intervals, the altitude, the temperature and the humidity of the atmosphere of the underground mine, the properties of the fuel, the operator's training and experience level. Necessary ventilation quantities were calculated based on exhaust gas concentration measurements, site specific relationships between pollutants and adjusted air quality indices. Diagrams comparing necessary and recommended air flow for several equipment groups featuring two engine types and for different maintenance intervals are presented.

Jan 1, 1998

By Howard I. Young

WHEN so many statements are being made relative to the requirements of zinc metal, it is difficult for some of us who are acquainted with the industry to visualize how it is possible to step up production so as to supply some of the fantastic requirement figures that are published from time to time. I shall attempt to approach this subject from the standpoint of existing conditions which affect production, also keeping in mind the price ceiling under which the industry operates. Total production of primary and secondary zinc in the United States for 1941 will be about 878,000 tons, to which should be added about 36,000 tons of Mexican slab zinc available for consumption or export from the United States, giving a total available of 914,000 tons. Production of slab zinc of all grades in 1942 should be 953,000 tons. Adding the available Mexican supply should bring the total to 989,000 tons.

Jan 1, 1942

By W Newns

This paper describes laboratory and in situ tests and determines a set of parameters for stiffness and strength properties for a weak sedimentary rock mass, the East Coast Bays Formation of Auckland. The parameters derived are discussed in relation to peak strength and in respect of deformation limits associated with sequential excavate and support (SEM) or conventional tunnelling.

Mar 8, 2011

By J. S. McEwan

This paper describes the derivation of a set of simultaneous algebraic equations that can be solved to produce a rigorous theoretical mass balance around solution mining wells. This mass balance can then be compared with a mass balance calculated from field measurements to provide the percentage of mass balance closure. Significant deviations from the closure can be an indication that the wells are either gaining or losing circulation fluids. The equations also provide calculations for the amount of water and dissolved mineral that accumulates in the well during the mining process, as well as the net mining rate. Equations for both single mineral mining and multiple mineral mining are discussed. They can easily be formatted into spread sheets for rapid calculation of field measurement data.

Jan 1, 2010

By Emory Smith

The preface of the United States Bureau of Mines Manual of First Aid Instruction contains the following paragraphs: One of the most important inquiries that Congress has authorized the Bureau of Mines to conduct relates to health condi- tions among those engaged in the mineral industries. Investigations made early with a view to bettering these conditions demonstrated the need of prompt care of injured miners, as, under the difficulties inherent to mining and other mineral industries; wounds seemingly unimportant, if not treated promptly, may become infected and possibly cause permanent crippling or even death of the porach. In the past many seriously injured persons have been treated by fellow workers ignorant of approved means of treatment and transportation and have been handled in such a manner as to cause suffering and to accentuate injuries to such a degree as to bring about permanent disablement. Accordingly, the need of general instruction in first aid became apparent. It must be recognized that the conditions in and about the mines, mills, smelters, quarries, oil fields, etc., usually present difficulties not found in large industrial centers where experienced surgeons are available and hospitals close at hand. Many mines are isolated and, when an accident occurs several miles underground, there may be a serious lapse of time before the injured person can be brought to the surface and taken to the hospital or given attention by a sur- geon who may have to come a long distance. Under such conditions it has been frequently demonstrated that, if effective first aid is not given, the injured person may die or become permanently crippled... First-aid instruction has been found to be an excellent aid3in pre- venting accidents. In addition to the immediate relief of injured persons, it has been found that most persons while in the act of practicing dressings for

Apr 1, 1931

By Robert E. Mazurak

Mines and plants for sale, downsizing, bankruptcies, consolidation, slab imports, minimill growth displacing traditional integrated steel-making. These are some issues for North American iron ore and integrated steel producers. But the blast furnace still remains the workhorse of the ironmaking industry. And direct reduction and other alternate ironmaking technologies have yet to make any serious inroads in North America. How come? This article addresses the current state of primary ironmaking in the changing North American steel industry, the direct reduction market and new technologies under development that may hold some promise.

Jan 1, 2003