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By W. W. Adams

Because of insufficient funds for printing, the Bureau of Mines was unable to publish its annual bulletin covering accidents at metal mines in the United States for the year 1933. A brief mimeographed summary of the principal statistical data for that year was released to the public late in 1934. Since then reports for 1934 have been received from the mining companies, and in order to avoid further delay in releasing this information to the mining industry and others interested in the prevention of accidents in mining, statistics for both years are presented in this publication with a minimum of interpretation and comment. The fatal-accident rate for the metal and nonmetallic mines (excluding coal mines) of the United States was more favorable in 1933 than in any previous year since 1911, the first year for which the Bureau of Mines obtained reports from the operators. Further progress was made in 1934, when the fatality rate was even lower than that of 1933. On the other hand, the nonfatal-accident rate, which had reached its lowest level in 1932, increased in 1933 and increased further in 1934, although not to such an extent as to prevent the rate for either of those 2 years from being better than that for any year previous to r1931.

Jan 1, 1936

In formulating its strategic plan in 1998 the New Zealand Minerals Industry identified two related critical issues facing it. These are, broadly speaking, the issues of access to minerals; and the perception the public has towards the industry and its behaviour towards the environment. This presentation will report on the Industry's response to the public perception issue. The Industry has, through the NZMIA Council, and its Communication and Website Committees, developed and implemented strategies covering: communication through the print media, and through its website www.minerals.co.nz, a long-term educational outreach programme with schools, focussing on the significance of minerals, their contribution to community wellbeing and the negligible long-term environmental effects of the Industry's activities.

Jan 1, 2000

By Randal Martin

Recently, questions regarding the influence of atmospheric temperature and humidity levels on airblast levels have arisen at a number of blast sites. Humidity is alleged to have contributed to high levels of disturbance within communities surrounding blasting. In some cases, local regulatory agencies considered adopting guidelines to specify humidity and temperature ranges under which blasting cannot take place. However, it is normal blasting industry practice not to consider humidity or temperature effects, in the absence of inversions, on airblast levels. When blasting is conducted in the vicinity of residential structures, the influence of weather on the propagation and attenuation of airborne noise from the blasting site is always a concern. Sound naturally attenuates in air with distance from the source. A part of this attenuation is attributed to divergence at the airblast wave front, while the remainder of the attenuation is an accumulation of various factors that include temperature and barometric pressure, absorption in air due precipitation and vegetation, wind and temperature gradients, atmospheric turbulence and topography (Beranek, 1971). Wind speed and wind direction, as well as vertical and horizontal temperature gradients can cause airblasts to focus in local regions surrounding blasting operations and may result in air pressures greater than expected. In fact, wind and temperature inversions can actually increase sound levels with distance from the blast site. Close to the blast site, the effects of inversions may be negligible but may exceed 10 dB at 800 m or greater (Davis and Cornwell, 1991).

Jan 1, 2001

"U.S. Bureau of Mines Publications and Articles, 1994 with Subject and Author Index Compiled by Office of Public Information U.S. Bureau of Mines (USBM) Department of the InteriorINTRODUCTIONThe U.S. Bureau of Mines (USBM) was established in 1910 to conduct inquiries and scientific and technological investigations on mining and the preparation, treatment, and use of mineral substances; to promote health and safety in the mineral industries; to conserve material resources; to promote economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purpose of this Act.""In accordance with this directive, USBM reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-USBM publications. This edition describes reports and articles published during calendar year 1994. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960; 1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960; 2 andthe 5-year lists of publications and articlesfrom January 1, 1960, to December 31, 1964,3from January 1, 1965, to December 31, 1969,4from January 1,1970, to December 31,1974,5from January 1,1975, to December 31,1979,6from January 1,1980, to December 31,1984/and from January 1, 1985, to December 31,1989.8"

May 1, 1995

By C N. Whata

While there is no specific obligation on the part of any applicant to consult directly with tangata whenua (people of the land), recent cases highlight the need to engage in active consultation in order to avoid serious objections and delay, particularly where a proposal may affect the matters referred to in section 6(e) (Waahi tapu/sacred places) and 7(a) (KaitiakitangaiGuardianship) of the RMA.   The Environment Court has shown some sympathy for tangata whenua where waahi tapu and other significant matters of cultural concern are at risk because of a proposed development. There are several practical steps that can be taken to minimise the potential for serious objection including: ò knowing who to contact and how to contact them; ò demonstrating empathy for the concerns of tangata whenua; ò engaging in proactive consultation, for example meeting at a time and a place that is suitable to tangata whenua, and a preparedness to meet the costs of tangata whenua etc; ò demonstrate an awareness of tangata whenua issues; being aware of the types of mechanisms that are available to remedy, avoid etc adverse effects on matters of concern to tangata whenua.

Jan 1, 1997

By H. C. M. Gordon

IT is essential to the success of any mining op::ration that the roadways through which the material wrought and ocher materials and supplies are to be transported should be kept in such condition that this transportation cart be effected rapidly and without difficulty. The longer the roadway and the greater the tonnage to be taken over it, the more necessary it becomes chat the construction and maintenance of the road be such chat traffic delays can be reduced co a minimum. le is proposed co deal with the development and construction of roadways serving longwall operations and, since a recreating system of longwall is worked, as a rule, only where roadways driven in the solid coal can be readily maintained, the discussion will be confined co advancing longwall roads which are driven through areas from which the coal seam has been totally extracted. In order to construct a roadway through extracted ground in such a manner that it will remain in a state of reasonably good repair without undue maintenance, it is necessary chat everything possible be done to bring the overlying strata co a state of equilibrium as quickly as this can be effected, and the operations should be so planned that future workings will not disturb the equilibrium so set up more than can be avoided. Obviously, the readiest way to obtain a stable roadway is to develop it by tunnelling through a settled waste. However, this cannot always be done, as some of the roadways must be developed and constructed as the walls progress, but level or lateral cut-offs can be constructed in this manner. Main-slope roads can be developed in a similar manner after the coal has been extracted and a waste formed for at !east five hundred feet on either side of the line of the permanent roadway from temporary subsidiary roads developed for this purpose along one or other of the flanks of the waste to be formed. This interval must be obtained in order chat the lacer extraction of the seam will not set up movements in the waste immediately overlying or adjacent to the constructed roadway, thus upsetting the equilibrium of the strata and distorting the road.

Jan 1, 1940

By S. H. Ash

NINE-TENTHS of the total anthracite deposits of North America are in Pennsylvania. Corrosion of pumping equipment by acid mine waters has been experienced at tremendous cost by mining companies in the anthracite region of Pennsylvania, for many years in many ways. The design and specifications of the large centrifugal pumps as provided in the proposed mine-drainage system (7-35, 45, 46, 48, 54, 64, 70, 71)° make it imperative that a metal or alloy be recommended that has the highest corrosion resistance and, at the same time, acceptable properties suitable for general workability (welding and machining). This report presents data on the corrosive and erosive effects of acid mine waters in the anthracite region on metals and alloys for pumping equipment and drainage facilities necessary to remove or control this water.

Jan 1, 1955

The selection of the best comminution circuit for the preparation of concentration feed is a compromise based on economics, energy efficiency, labour costs, steel consumption, availability and other factors specific to each case. It is postulated that the selection must be a choice of one of the eight basic comminution circuits which can be divided into two basic groups, (1) autogenous or semi-autogenous primary mills with or without a secondary grinding stage and (2) fine crushing usually in cone crushers followed by a rod mill-ball mill circuit or a single stage ball mill circuit. The accuracy of selection may be improved by pilot plant and laboratory tests which are described in this paper. For (1) above, testing includes media competency tests with standard impact crushing, grindability and abrasion tests followed by pilot plant tests. For (2) above, bench scale crushability, grindability and abrasion testing is available. It is suggested that, through these tests, it should be possible to eliminate all but one in each group of basic comminution circuits. Then engineering and economic studies should lead to the best comminution circuit for the specific requirement.

Jan 1, 1984

By A. Gronningsater

Introduction As is well known, the fight between the blast furnace and the reverberatory furnace in copper smelting during the second decade of the century ended with a victory for the latter, a result which must largely be attributed to the introduction of flotation methods. To my knowledge, no new blast furnace has been blown-in at any American copper smelter since the War. As the metallurgy of nickel, up to and including matte smelting, is generally considered a close parallel to that of copper, the introduction of reverberatory smelting in the big new smelter of the International Nickel Company at Copper Cliff, built in 1928-30, seemed a logical adherence to a well established trend. In view of these facts, considerable comment was made when Falconbridge Nickel Mines decided to retain the blast furnace in their smelter built about the same time, in 1929. A presentation of the reasons governing this choice should therefore be of interest. The basic principles underlying the Falconbridge practice, and the considerations guiding the successive steps in the operations, will be discussed in the following. To understand the problems involved, the character and mode of occurrence of Sudbury ore must be kept in mind. Large amounts of disseminated ore are generally present. Although the gangue usually runs only about 50 per cent Si02, the ore hoisted as a rule contains more silica than needed in the smelting operation; until recently this excess was removed entirely by hand picking (in later years supplemented by magnetic sorting methods), a difficult and not very satisfactory method, in which 'the border line between ore and waste is entirely arbitrary, and therefore too much depends on the judgment of the picker.

Jan 1, 1934

Jan 1, 1998

By Tuncel M. Yegulalp

This article summarizes some of the results of the continuing research activity at the Henry Krumb School of Mines, Columbia University, directed towards a better understanding of the stochastic behavior of slurry flows in underground coal-slurry pipeline systems. The slurry system under consideration here replaces all conventional haulage systems between the coal face and the coal preparation plant on the surface. At the beginning of the pipeline system, flow rate and frequency of coal slurry is very closely related to the activities of production equipment at the coal face. Due to several scheduled and unscheduled interruptions in continuous miner's coal mining activity, resulting slurry flows possess stochastic characteristics. Proper understanding of these characteristics is believed to lead to a more realissic and economic design of slurry handling equipment. Fundamental ideas supported by field observations are presented and a Semi-Markov model of the slurry flows is developed. As a result of this formulation, behavior of combined slurry flows from N independent coal faces can be expressed in analytical form. The contents of a slurry surge tank receiving slurry flows with certain stochastic characteristics is investigated as a function of discharge pump characteristics and time.

Jan 1, 1981

By William J. Campbell

The columbite-tantalite mineral series was studied by various instrumental techniques to establish the relationship of density to composition. The samples used were carefully selected to obtain a mineralogical purity of at least 98 percent. Impurities were determined by optical microscopy, X-ray diffraction, and optical and X-ray spectroscopy. Each sample was analyzed by fluorescent X-ray spectroscopy for iron, manganese, columbium (niobium), and tantalum. The existence of a unique relationship in this isomorphous series permits a simple correlation of the intensity of a spectral line with the concentration of the analytical element.

Jan 1, 1955

By Todd Clarke, Ralf Winterberg

For more than a decade the tunneling industry has explored the potential and benefits of macro synthetic fiber (MSF) reinforced concrete solutions for precast tunnel segments. Parallel to industry investigations, academic research is being undertaken to better understand this material when subjected to the typical loads expected during mechanized tunneling. This paper investigates the performance of MSF reinforced precast concrete tunnel segments by means of an experimental program comprising testing of full-scale tunnel segments. The presentation of the satisfactory results of the experimental testing regime will be complemented by a brief case history from a successfully executed project—an America’s First.

Jun 13, 2021

By Adam Moore, Peter Radziszewski, Matt Gallimore

"Stirred mill technology dates back to 1928 where the idea to use “an agitator and spherical grinding media” was presented. In the context of the mining industry, interest in stirred milling technologies has grown over the last 20 years where the typical observation reported inDespite these developments, the tumbling mills are continuing to be used in fine and ultrafine grinding applications. The main reason for this, as communicated at the Canadian Mineral Processors roundtable discussion in 2013, is that the comfort level in understanding stirred milling technologies is not at the level of that of tumbling mills.At CMP 2014, one contribution was made to explore how mill design affects power and energy in a stirred mill. While the 2015 CMP paper explored the application of one scale-up methodology to the Gibraltar case. For the CMP 2016, the aim of this paper is to contribute to increasing the general comfort level with stirred milling technologies by developing a better understanding of the different scale-up methodologies used. This will be accomplished by first completing an overview of the scale-up models found in the literature followed by a review of the different testing and scale-up procedures. This review will be supported by a number of case studies found in the literature. The paper will close with a discussion on some of the challenges that these models and methodologies have and how future research might contribute to overcoming them.IntroductionStirred mill technology dates back to 1928 where the idea to use “an agitator and spherical grinding media” was presented (Stehr, 1988). The year 1948 saw the successful application of Du Pont’s “sand mill” for pigment grinding. Subsequent years have led to the development of different types of stirred mills spanning a number of industries that require fine and ultrafine grinding."

Jan 1, 2016

By A. G. Provost

On April 3, 1981, Harrison Western Corporation was awarded a contract by Amax Alloy - A Division of Amax Inc., to sink the Henderson #5 ventilation shaft. The project was located on the Henderson Mine site 88 kilometers west of Denver near the town of Empire, Colorado (Figure I). The Henderson No. 5 Shaft, located in an Alpine environment at an elevation of 3145 meters, was a 9.8 meter diameter concrete lined shaft with a total depth of 793 meters. Work started and continued with Harrison Western employees until January 15, 1982. At that time, Amax made the decision to continue the shaft-sinking with their own labor, and with Harrison Western providing supervision under a management service contract. Shaft sinking continued under this arrangement to October 1, 1982, at which time Amax put the Henderson No. 5 project on standby status until further notice.

Jan 1, 1986

By David A. Lipton

In the summer of 1985, at the request of the U.S. Forest Service, the U.5. Bureau of Mines examined the 109,000-acre West Big Hole study area to evaluate its identified mineral resources. The study area is in Beaverhead County, about 50 mi west of Dillon, MT. Four lode properties within or adjacent to the study area contain an estimated 452,000 tons of identified subeconomic gold-silver resources. Resources ranged from 900 to 302,000 tons, with estimated grades between 0.02 and 0.23 oz/ton gold and as much as 4.8 oz/ton silver. Gold, silver, and base-metal content in samples of poorly exposed mineralized structures indicate that exploration may identify resources on 18 additional lode properties within the study area and 5 properties adjacent to it.

Jan 1, 1988

By Yi-Shen Li

This report has been prepared by Lockheed Missiles & Space Company, Inc. (LMSC), under United States Bureau of Mines Contract No. H0220040 dated 21 June 1972 for the design, development, fabrication, and certification of the One-Hour Self-Rescue Breathing Apparatus (PBA). The PBA is a self-contained, oxygen-generating, CO2-removing closed-loop breathing apparatus that provides a minimum of 1 hour of breathable atmosphere during escape from a mine with a contaminated or oxygen-deficient atmosphere. This Cost-Plus-Fixed-Fee (CPFF) contract has been successfully completed in a three-phase program. The Phase I tasks included the design, development, and fabrication of prototype units developed at LMSC in accordance with the requirement of the Code of Federal Regulations (CFR) Title 30, Chapter 1, Subchapter B, Part 11 (Appendix A), and was submitted to the National Institute for Occupational Safety and Health (NIOSH) for joint NIOSH and Bureau of Mines certification testing.

Jan 1, 1974

By K. C. Garner

The visit reported was made with support from the 1997 J.C. Boyle travelling scholarship. The management and control of hazardous gases released into the underground environment are an integral part of coal mining. The power-generations stations at Appin and Tower collieries, with a combined electrical output of 94 MW, have been operating for some time and have demonstrated a technology that is able to exploit the available gas fully. Contributory factors have been the development and introduction of directional drilling techniques, pre- and post-drainage of coal, relatively high seam permeability, a high gas content of the worked seam, high production rates and a willingness to embrace new ideas and technology

Jun 21, 1905

By Marco Taipe

Uno de los mayores costos del proceso minero es el de perforación, en tanto emplea aire comprimido. Por tal motivo, la industria minera busca diferentes alternativas para reducir los costos del aire comprimido o eventualmente a través del uso del sistema electro-neumático. Este sistema es de fácil instalación y mantenimiento puesto que se basa en electricidad y agua, reduciendo costos y a su vez mejorando las condiciones de trabajo a través de la versatilidad del presente sistema.

Sep 12, 2011

By Robert S. Sanford, Harold C. Pierce

"At one time the Alaskan Eskimo lived in many small settlements scattered along the Arctic coast. These settlements extended as far south as Bristol Bay and several miles inland on the large rivers. When the white man established trading posts, schools, hospitals, and missions, these people gradually congregated around them in a few large villages. The natural fuel supply near many of the large villages along the Arctic coast became exhausted as a result of the abnormally large influx of people from small outlying settlements.The population of Barrow, Alaska, according to the 1940 census, is 363 persons, but since that time it has increased considerably, and later estimates place the present population between 400 and 500 persons. With the exception of 25 white persons, the entire population is comprised of Eskimos.The government maintains a school, hospital, radio station, and weather station at Barrow. In addition to the government, installations, there is a church, a privately owned trading post, and cooperative store owned by the Eskimos.For many years the Barrow Eskimos depended on driftwood and petroleum residue from Cape Simpson for their fuel supply. This fuel provided not only warmth for the Eskimo during the long cold winters but also heat for melting ice, the only source of 'water during .the winter. In recent years the sources of petroleum residue and driftwood have not been adequate to meet the demands for fuel During the winter of 1942-43 and again in 1943-44, Barrow experienced an acute shortage of fuel.The fuel problem at Barrow was brought to the attention of Governor Ernest E. Gruening, who was instrumental in getting a Bureau of Mines engineer4/ to investigate reported coal occurrences in the vicinity. Coal deposits along the Meade River and at Peard Bay were examined during the spring and fall of 1943. The Alaska Native Service shipped in mining equipment in September 1943 and commenced stripping an open-pit mine on the Meade River in June 1944. In conjunction with this work, an engineer5/ of the Bureau explored by churn drilling to determine the tonnage of- coal in the vicinity of the mine. In addition to this work, the Bureau of mines examined coal deposits in Peard Bay area and along the Kuk River south of Wainwright."

Nov 1, 1924