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By G. R. FITT, S. R. B. Cooke, C. W. Davis, V. H. Gottschalk, C. G. Maier, C. E. Wood, R. S. Dean, S. B. THOMAS, John Gross, E. P. Barrett, T. L. Joseph

Lack of funds has prevented publication of much of the metallurgical work of the Bureau of Mines during the past 2 years . The present progress report covers studies in the direct production of iron and steel . The experimental work was carried out in cooperation with the universities of California , Minnesota , and Missouri . Complete reports will be published when funds are available .

May 1, 1934

A mathematical model of a decision is represented by the table in Figure 4. The numbers in the matrix are a measure of the effectiveness of each alternate for an objective. In this case, it is the per cent of desired profit that is satisfied by each alternate for each objective. By adding all of the values in a row, we have a measure of which alternative is best for both objectives. However, if you think that alternate 1 is necessarily better than alternate 2, you are wrong. Why? Because the weight of the objectives may not be equal. It could just be that this plant can sell more than it can produce, so that the loss in profit represented by increased sales is more than twice as important as reductions in costs. (See Figure 5). In that case, let us weigh objective 1 as 30 per cent and objective 2 as 70 per cent. It must also be obvious that the sum of all the "objective weights" must equal 100 per cent. Now, by evaluating our alternates according to their weights. we find that alternate 2 is better than alternate

Jan 1, 1964

By D. E. Andrews

The objective of this study was to investigate the environmental effects of slaking of surface mine spoils. To accomplish this, both field and laboratory programs were undertaken, supplemented by a thorough literature search. The field program consisted of drilling the highwall as well as test pitting in recent, two-, five, and ten- year-old spoil piles at four active mining sites in the eastern bituminous coal fields. Pertinent observations were made and samples collected for laboratory analyses which consisted of several standard geotechnical, agronomic, and geochemical tests. Durability tests utilized included jar slake, cyclic wet-dry, rate of slake, and slake durability tests. Correlation between field and laboratory portions was made- and results presented. The report is concluded with a discussion of the slaking process and associated environmental impacts, proposal of a preliminary classification system for use in premine planning, and presentation of management techniques to optimize the slaking process.

Jan 1, 1980

By Ted Schwinden

It's my pleasure to welcome the Rocky Mountain Coal Institute to Montana. Now that you've ended a 74 year history of meeting outside our borders, I hope you'll be back more often. Even if I can't convince you to come back before 2060, when another 74 years will be up, I'm confident the Kalispell and Flathead Lake area will do the persuading for me. In recent weeks, I've made a number of speeches around the state pointing out just how wrong the revenue projections in Montana's state government made in April of '85 were when we came to April of '86. Since the middle of this month, Montana's legislators have been in Helena struggling to balance a state budget that, by the end of fiscal year '87, threatened to be some $88 million in the red. Other western states reliant on natural resource and agricultural economies have found themselves caught in the same deflationary spiral. The "window of opportunity" I proposed and the 1985 Montana Legislature passed, couldn't have been opened at a more difficult time. What was envisioned as an incentive to expand Montana's coal production, and our tax base, ran aground on low oil prices and excess hydroelectric power. De- spite the one-third severance tax rebate offered on new coal production, year-to-date figures published in the June 2nd Coal Week show that production in Montana is down almost 10 per- cent from last year. Again, we're not alone. Production in Wyoming is down 8 percent and in North Dakota, it has dropped 13 percent. An over- all 3 percent production decline in western states looks even worse when contrasted against a 12 percent increase for your eastern competitors. Montana's "window of opportunity" had the potential to be a significant signal to your industry. That potential was quickly tempered by the inability of Arab nations to stabilize world energy prices. If any of us had forgotten, the last twelve months have reminded western states that the well-being of our natural resource economies has a tremendous impact on the ability of all levels of government to provide services. The past year has also driven home that in the world of business and in the business of the world, risk-taking is still the name of the game. The Western Governors recognize the problems facing this industry - and our states - and we're prepared to fight for the future of western coal. In the past two decades, legitimate environmental concerns have created a vast body of new legislation affecting coal producers. The industry has been required to meet new reclamation standards - tough regulations relating to ground water, air quality and wildlife habitat. To the industry's credit, coal companies have hired professionals with the technical know-how to do it right. Rather than considering reclamation laws to be an unreasonable burden, today's coal company is more likely to view its reclamation efforts as a source of corporate pride. In a sense, the industry and the agencies which regulate it have matured together . . . although at times OSM is reluctant to admit that either of us capable of or willing to play by the rules. Certainly some abuses exist and OSM's oversight has been helpful in ensuring parity between those states willing to comply and those that would rather defy federal law. Nonetheless, penalizing the more modem and responsible western coal industry for abuses that occur elsewhere is both unfair and counterproductive. Federal penalties range from "cruel and unusual" reporting requirements to the proposed electricity tax that would effectively force utilities and ratepayers who have already met the sulphur emission standards to subsidize those who have dodged their cleanup responsibilities. As a member of the Alliance for Acid Rain Control, I have joined corporate leaders, academicians, environmental representa-

Jan 1, 1986

By Stephen D. Hill

The Bureau of Mines devised and constructed a modified Knudsen effusion apparatus, permitting a constant measure of the weight of effusing vapor, to determine the equilibrium vapor pressure of metal halides at temperatures up to 1,200° K and over the pressure range 10-5 to 10-2 torr. The reliability of the apparatus was established by determining the vapor pressure of potassium chloride. After correcting for partial dimerization of the vapor, data obtained on solid KCl between 750° and 950° K can be expressed by the following equation:

Jan 1, 1966

This report is in partial fulfillment of Contract S0241051 awarded to COMINEC on June 27, 1974. 'Me purpose of the work under this contract is to develop a conceptual design for an automated longwall mining system. The conceptual design will serve as the basis for future design and development of an automated longwall mining system capable of sustained production in excess of 2,500 tons per shift with reduced manpower which will ultimately be demonstrated in an area where conventional longwall mining has been successful. 1.2 DEFINITION OF THE PROBLEM 1.2.1 Why An Automated System The most obvious benefit of automation and remote control in a longwall mining system is the reduction of accidents consequent upon a reduced working force in the hazardous face areas. However, another important aspect of the problem is the skilled labor shortage which is being compounded by the need for vastly increased coal production. The United States coal mining industry had a working force of almost 600,000 miners in 1928 but was able to muster only 145,000 miners in 1970. The miners required to staff the additional working sections and the new mines necessary to meet our energy needs are simply not available. Only automation and remote control will permit a reduced work force with increased production by keeping the face equipment operating continuously.

Jan 1, 1975

By Anil Mahyera

This report present the results of a laboratory and field research program aimed at design and development of a torque-thrust controlled bolter with the capability to (1) predict the "quality of anchorage" attained while installing mechanical anchor roofbolts, and (2) improve the uniformity and tension levels achieved among a group of roofbolts. The prediction accuracy of the anchorage quality algorithm ranged from low to moderate because of the complexity and variability of the phenomena involved. The best roof support with mechanical anchor bolts was found to be achieved by simply installing them under ? proper torque-thrust control, and with ? a hardened washer under the bolthead. This procedure resulted in an improvement in uniformity of 3 times, along with an increase in mean tension levels of 75% over conventionally installed roofbolts.

Jan 1, 1983

By M. R. Yenchek

The U.S. Bureau of Mines designed and constructed sensitive and coordination-free ground-fault relays (GFR's) for use on mine power systems. First, a list of GFR attributes for mine ac utilization applications was compiled. These practical guidelines specified design, construction, transient immunity, reliability, and operating criteria. The time-current characteristics of the ac and dc units, subsequently fabricated, were designed to be below the human electrocution threshold. The significant and highly variable capacitance of high-voltage distribution cables was found to preclude the sensing of ground currents in the milliampere range. However, the coordination-free system developed for high-voltage distribution should enhance safety by significantly decreasing response time to ground faults. Implementation of the sensitive GFR technology in the mining industry has the potential to eliminate the majority of injuries and nearly all the deaths resulting from contact with energized components.

Jan 1, 1990

By P. H. Francis

In This report, factors which currently enter into the design, manufacture, and quality assurance of explosion-proof enclosures are reviewed, with special emphasis given to the sealing concepts and sealants/cements, per se, for lenses. The physical and mechanical properties of a number of representative sealants and adhesives are measured, and found to exhibit great variance, with few discernible trends which might afford a firm base on which to establish minimum property standards. Accordingly, acceptance criteria for adhesives and sealants are suggested based on the survivability of an explosion-proof enclosure as a structure rather than upon the minimum mat real properties of its constituents. Procedures or surface preparation of adherends, and for quality assurance, also are proposed.

Jan 1, 1980

By G. E. McElroy

When mechanical ventilation is to supersede the natural ventilation of a mine it is desirable to determine what resistance the mine as a whole offers to the flow of air in order to specify properly the limiting duties of a ventilating fan. The relation of pressure to volume of flow for the mine as a whole may be calculated from experimental data, or it may be determined directly by measurements of volume of flow and the natural draft pressures causing flow; but in both methods the determinations are affected by many variables. With the intention of making a practical application of both methods, a small metal mine in process of development at Butte, Mont., was selected by the writers as the object of experiments planned to compare the mine resistances determined by measurements of natural draft and volume of flow with those calculated from experimental data. Four sets of teats were made with natural draft in October, 1925, December, 1925, April, .1926, and September to December, 1926; the last set consisted of a series of weekly observations. DESCRIPTION OF MINE The mine selected for the experiments was a typical vertical shaft metal mine in the development stage. No stoping had been done, and ventilation was confined to shafts, crosscuts, drifts, and raises. Figure 1 is a dia¬grammatic sketch of the main openings. All were timbered with full sets on approximately 5-foot centers. The shaft compartments were 4 by 4.5 feet, and one in each shaft was partly blocked by staggered manway landings. A pump column in the upcast shaft was discharging about 280 gallons a minute of water at 70° F. from the 1,000-foot level. The drifts were slightly sinuous, but the crosscuts were exceptionally straight and uniform in area; both drifts and crosscuts were about 5 by 7 feet in cross section. The raises were composed of vertical sections joined by frequent 450 offsets; each had three 4.5 by 4.5-foot compartments, of which two were plank-lined ore chutes and one was partly

Jan 1, 1928

By E. J. Burrough

Coal Reserves The Crowsnest Pass coal fields form part of a greater area which comprises the Inner Foothills belt of the Alberta coal fields and the southeastern coal fields of British Columbia. The most valuable and most extensive reserves of the bituminous coals of Canada are concentrated in this?area, of which the Crowsnest Pass fields form an important part. The extent of these coal reserves together with those of the rest of Canada were recently studied by the Geological Survey of Canada for the Royal Commission on Coal of 1946 (1). Quotin from the report, it is of interest to note that, prior to this work, the most widely known, and in fact the only Canadian-wide estimates of, coal reserves of Canada available to the Commission were those prepared by Dr. Dowling in 1913 (2). At that time it was estimated that Canada's reserves of coal were over twelve hundred billion tons. The more recent estimates of mineable coal for the whole of Canada are of the order of 10 per cent of that figure and are reported. as 99 billion tons, which is further reduced to 40 billion tons on the basis of the estimation of recoverable coal. This considerable divergence in estimated reserves is explained in part by the big difference in the bases of measurements. For example, in the original report, seams of one foot occurring at a depth of 4,000 feet were included in the estimates.

Jan 1, 1951

By G. Duncan

Distinct trends in grinding mill technology have emerged in recent years. In an effort to optimize overall mill performance for the needs of the End User, broad measures of logistical speed, process flexibility, operational risk, and overall costs now exert greater influence on the specification of grinding equipment. As a result, innovative alternatives to conventional grinding mill structures, supports, drives, feed, and discharge configurations are now being offered and selected with greater frequency. This paper investigates these trends in grinding mill technology, utilizing optimization and decision-theory techniques. In particular, the paper considers how specific advances in process design, product engineering, manufacturing techniques, and mining operations continue to relax technological constraints, enabling further mill innovation. In this context, a methodology is presented, illustrating how proper selection and specification of grinding mill components and configuration can target an optimization of the four End-User performance measures listed above..

Jan 1, 1999

By P. L. Dunn

Automatic control of fine coal cleaning circuits has traditionally been limited by a lack of sensors. Although several nuclear-based analyzers are available, none have seen widespread acceptance. In this investigation, image analysis is used for on-line determination of ash content in fine coal slurries. The ash content of a flotation tailings stream is correlated to the mean gray level of the slurry. Based on a 90% prediction interval, an analysis of sensor performance indicates an accuracy of 73 ± 4% ash over a range from 65-90% ash. While this result is comparable to existing nuclear-based analyzers, the video-based system is only a fraction of the cost. The sensor is currently installed at the Middle Fork preparation plant owned by Pittston Coal Company.

Jan 1, 1997

By Robinson Leon-Diaz, Alberto Jaen-Toribio, Raymond Blanchard, Mike Deevy, Miguel Fuentes-Llanos

"Tunnels designed to NFPA 502 are required to withstand the RWS time-temperature curve, more specifically prevent progressive spalling and loss of strength of steel reinforcement. Fire boards or spray-on layers can be effective, however, these solutions have capital and whole-life cost implications. The use of “fire resistant” concrete based on a suitable aggregate with polypropylene fibers has also increased in recent years. This article presents a new methodology for thermal and structural analysis of segmentally lined tunnels, which permits the analysis of project specific fire curves and an assessment of different fire protection strategies. The effectiveness of fire boards is assessed along with whether “fire resistant” concrete alone is a viable means of achieving the required protection. Finally, since NFPA 502 recommends water-based fixed fire-fighting systems for Category C and D tunnels, we discuss the question of how a fixed fire-fighting system should be addressed within the structural design. INTRODUCTION Protecting road tunnels from structural damage and collapse is a key requirement for both life safety and business continuity. Where road tunnels are part of key highway corridors, protecting business continuity is a high priority for owners, operators and the Authority Having Jurisdiction. For existing tunnels, compliance with NFPA 502 may require upgrades with either passive fire protection and/or water-based fixed firefighting systems. For new tunnels, compliance with NFPA 502 requires a combination of good practice in design and fire testing. A water-based fixed firefighting system is a Conditionally Mandatory Requirement1 for Class C and D tunnels, i.e. all tunnels greater than 300m and 1000m long respectively. The basis for fire safety design of new tunnels and assessment of existing tunnels is the worst-case fire scenario. A number of factors, including but not limited to the following, influence this design fire scenario:"

Jan 1, 2016

By F. A. Forward

Introduction The main line of ascent in the development of the nickel industry may be traced back through the International Nickel Company of Canada, Limited, to its earliest antecedents, the Canadian Copper Company and the Orford Copper Company. Mining geology is but one aspect of the overall development of this organization, and the stress it has placed on geology grew according to the need. In the early days, intensive geology was not required because ore supply was not one of the main problems of this or any of the pioneer companies. The difficulty then was to find economic methods for reducing the ores to nickel and copper, and markets for absorbing nickel in the face of a limited demand from consumers heavily prejudiced in favour of the New Caledonia product. "Very early in the history of the region it was patent to everyone that to share in the full benefits of the industry the same individuals or company must control the whole of the operation necessary to manufacture the finished product' (1, p. 45). These conditions were fulfilled for the International Nickel Company in 1902 when the Canadian Copper Company (incorporated 1886), with its ample ore supply, took the initiative to merge its interests with those of the Orford Copper (Refining) Company (incorporated 1887) to form the new company which, with reorganizational changes, emerged as the producer of the overwhelming bulk of the world's nickel. The Mond Nickel Company, Limited, entered the field in 1899 with a refining process, and over a period of years acquired ore through purchase of mining properties. This Company operated successfully and independently until 1929 when its assets were joined with those of the International Nickel Company in order to permit the most economic exploitation of the Frood-Stobie orebody in which both Companies were interested.

Jan 1, 1948

By T. A. Klinefelter

ONE OF THE many services rendered by the Federal Bureau of Mines is the identification and general examination of ore and mineral samples. Many of these, coming from almost every State in the Union, are clay and shale samples. Other Government agencies, State geologists, universities, and other laboratories are often requested to make similar examinations. This publication describes methods of testing these samples. An earlier paper, published in 1943, described Bureau of Mines methods of testing such clays.3 This paper was to be followed later with another (part II) that would describe much more thorough testing than did the rather general outline of part I. Part I has been out of print for some time and needs revision, and part II was never written; hence, the present publication is designed to include part I and also those additions intended as part II. The tests presented in part I were simple, requiring only the ordinary equipment to be found in any good chemical laboratory. The second publication was to include a greater number of test procedures and information on increasing the accuracy and precision of those previously given.

Jan 1, 1957

By Chas. F. Jackson

The annual reports of the supervising engineers of the nine sections comprising the Mining Division are assembled here and constitute the annual report of the division. In planning activities the aim is to adapt them to changes in conditions, in the needs of the mining industries, and in the public interest; those that contribute most to solving the present problems are emphasized, investigations of less immediate importance being recessed if necessary. The strategic minerals investigations of the bureau afford an example of this change in emphasis to problems of immediate and urgent interest, and during 1941 they comprised, upon the basis of appropriations and expenditures, more than 90 percent of the work of the division.

Jan 1, 1941

By Andrea Brickey, RICHARD AMOAKO, Akshay Chowdu

Production forecasts derived from the medium-term schedule represent the best path forward for underground mining operations to achieve corporate and operational goals. Unforeseen circumstances, such as equipment breakdown, can cause significant deviations from established production forecasts in the short term. Such situations require timely mitigation of the effects of the deviations in order to stay as close as possible to the medium-term plan. This paper presents a deterministic mathematical formulation for short-term scheduling that addresses this challenge. The formulation is able to make up for deficits resulting from operational disruptions by minimizing deviations from medium-term production goals and mediumterm activity start dates. We demonstrate this in a case study by simulating disruptions involving reduction in ore extraction capacity and development advance rate. Aside from the rescheduling capability, this formulation can help mine planners conduct analysis on the impact of various disruptions on the schedule. The formulation can help identify those conditions or disruptions that are more detrimental to the achievement of forecast targets, or otherwise. The formulation also affords mine planners the flexibility to prioritize one production goal over the other, depending on operational conditions at the mine. In the future, we seek to incorporate in the formulation respirable dust, diesel particulate matter, and ventilation constraints in order to create more realistic schedules and enhance miners’ health and safety.

Sep 6, 2023

6889. Aslakson, C. I., and Swick, C. H. Gravity Observations in Peru and Colombia. Coast and Geodetic Survey,-Special Pub. 233, U. S. Government Printing Office, Washington, D. C., 1943, 18 pp. (Price, 10 cents.) In accordance with the policy of cooperation among American republics, the-United States Coast and Geodetic Survey in 1941 made gravity surveys in Peru and-Colombia. The information was desirable for determining the figure of the earth for geophysical purposes and for studying the relationship between intensities of gravity and deflections of the vertical. The survey instrument was the Brown pendulum apparatus. 11 gravity stations were established in Peru and 13 in Colombia. The results obtained at these stations are given in a table covering observed gravity, theoretical gravity, and anamalies. - V. S.

Jan 1, 1943

By S G. Li

Mine intelligent ventilation is an important guarantee to realise intelligent mining. It is the integration of the Internet of Things, big data, artificial intelligence, internet, cloud computing with ventilation technology, forming a complete ventilation system with intelligent perception, intelligent decisionmaking, intelligent emergency response and airflow control. In order to fully grasp the progress and trends of mine intelligent ventilation research in western China. The paper based on literature analysis and field application research, comprehensively expounds the main research and practical results of mine intelligent ventilation in western China, mainly analyses the development status of key technologies such as accurate and rapid determination of mine ventilation parameters, intelligent analysis and decision-making of ventilation and intelligent regulation of ventilation equipment, and introduces the field test or application of mine intelligent ventilation technology in western China. It lays the foundation reference for related research and improving the intelligent level of mine ventilation.

Oct 12, 2022