Search Documents

By Ming Ju Liu

China has been suffering from the most serious coal and gas outburst accidents. The situation has become worse than ever with the mining of deeper coal seams at higher production rates in a more complex underground mining environment, in order to meet the huge national demand for coal-fuelled power plants. In the year 2007 alone, more than 30 outburst accidents occurred in underground coal mines with a death toll of 258, and in the year 2008, as of May 22, nine outbursts have already occurred in Henan, Hubei and Chongqing, killing 68 workers. At the same time, China also experienced new trends of coal and gas outburst accidents since its coal production boom in the year 2001. These trends are of great importance for government agencies, coal mine owners and operators to take initiative and effective measures to prevent and control the occurrence of coal and gas outbursts in China?s widely spread outburst prone mining areas. This paper presents outburst data of China coal mines since 2001 and describes new trends of outburst occurrence in recent years, which include outbursts coupled with shocks or rock bursts of competent roof, outbursts in mines under development, outbursts in new mines and mines that have never suffered outbursts before, outbursts in mines that are believed to be of low gas content as well as outbursts in more long-wall faces. Based on the observation of outburst occurrence in China in the period from 2001 to 2008 as well as mining and geological conditions, detailed analysis of the possible causes that led to those new trends of outburst accidents is conducted. The analysis helps shed light on possible future remedies and the necessary measures to alleviate or eliminate outburst accidents in underground coal mines. Suggestions are put forward on future studies that could be of interest to national and provincial government agencies regarding strategic policies, proper technical management practice, identification of outburst prone coal seams, online monitoring of impending outbursts as well as prevention and control measures.

Jan 1, 2008

Prier to the date of this contract, Ocean Energy had developed and demonstrated a high efficiency fluorescent caplamp which operated from a standard 4 volt miner's caplamp battery. This unit produced about five times the light output of the standard incandescent miner's caplamp. The Company believed that the major market for this unique caplamp was in the industrial and municipal applications. Because of the additional safety requirements for coal mining use, and in conjunction with the much smaller market in the mining industry, the additional expense and difficulty of modifying this caplamp to comply with the Federal and State coal mine regulations were not considered at that time. Recognizing the potential of this lamp for improving illumination conditions for underground coal mining, the US Bureau of Mines contracted with Ocean Energy to make the required modifications to this lamp to bring it into compliance with the Federal and State of Pennsylvania regulations, and thereby, make this lamp available to the anthracite and bituminous coal mining industry. At the outset of the contract, the injection molds for the caplamp housing were being completed, and only prototype, hand fabricated, units were available for tests. The Bureau evaluated these prototype units and formulated a performance specification for the miner's version. Light level and distribution, weight, size, angle of tilt, and operating duration were all specified. In addition, it was required that the caplamp be com¬patible with existin charging equipment at the mines and that the final design be in full compliance with MESA Schedule 6D and he ultimately approved by MESA, Approval and Testing, as well as by the Pennsylvania Bureau of Deep Mine Safety. The scope of this contract covered the modifications required to achieve these objectives. It was agreed by the Bureau that all rights to the lamp, including design, material combinations, circuitry, etc. would remain with Ocean Energy. The charger/adapter system and components, which were developed under contract funds, are disclosed hero and become public knowledge and property. Patent applications have been filed by Ocean Energy to protect the mechanical and electrical design aspects of the lamp. It should be noted that this report contains details, designs and data which may be covered by one or more Ocean Energy patent applications, and disclosure herein is made only to provide better understanding of the contract results.

Jan 1, 1975

By J. Kempken, R. Degel, J. Kunze, R. König

The FeNi technology is currently dominated by high-power submerged arc furnaces, often designed as smelter as "two-inline-solution". To achieve the intended high efficiency, state-of-the-art design in good correlation with ores and reductants and an integrated layout of the whole plant is of great importance. An introduction will be given to general aspects in the production FeNi, plus a detailed overview of design principles for large FeNi smelters and finally some examples of innovations and research projects concerning Fe-Ni.

Jan 1, 2007

By D. C. Yates, G. V. Jolliffe

In the five coalfields of Staffordshire, there have been some 43 incidents of spontaneous fires and heatings which have required special attention in the past ten years. This total excludes incidents in the Thick Coal Seam of South Staffordshire, which was worked until 1967, and which was subject to an almost continuous series of heatings. The incidents have been classified to show the sites of occurrence, the contributory factors which may have caused them and the treatments applied to them. The remedial techniques, as practised in Staffordshire, are dealt with in detail, with particular reference to standard methods of stopping-off. Precautionary measures taken are described, including a "liability to spontaneous combustion" classification of all seams, and the setting up of an emergency organization with emergency stocks of materials and equipment. The paper is concluded by a few words on the organization and control at the time of an incident.

May 23, 1905

The greater part of this paper comprises the material used in a lecture delivered to the South Queensland Branch of the Australasian Institute of Mining and Metallurgy in September, 1949. It contains little in the way of original matter, its main purpose being to call attention to the need for research into the properties of Queensland coals and to indicate some of the lines such investigations might profitably follow.Since the lecture was given the Powell Duffryn (1949) 1 report, which has made an excellent start along these lines, has been printed. This report is, however, only a beginning, though a big one, and there is ample room for many years of work along similar lines.The paper is based largely on the work of de Jersey (1946, 1949)2,3,4,5 and Jones and de Jersey (1947)6, but these workers in turn owe a debt to the work of many British and American investigators, too many to enumerate. The subject is a very large one-to deal with it fully would require not a paper but a book; all the author can hope to do is to discuss very briefly some of the main lines of investigation and indicate some of their applications.The reason for selecting Queensland coals in particular is the widespread ignorance of the extent of the coal resources of that State and the almost complete ignorance, to within the last year, of the modern industrial purposes to...

Jan 1, 1950

By D. van Rensburg

Jointed rock slopes are generally stable, as there is no freedom of movement for blocks of rock. In an open- pit mining environment, blasting opens up space into which blocks of rock can fail, resulting in the common occurrence of slope failure. Prior to the blasting of a trim pattern, the immediate highwall is scaled, where loose rock material is removed by means of a mechanical scaler. As mining of the pit progresses, the height of the scaled highwall from the pit floor progressively increases. These highwalls are never scaled again for the remainder of the pit life, and time-dependant deterioration contributes to these highwalls becoming subject to rockfall and, sometimes, slope failure. This paper documents the development of a South African innovation, a remote-controlled mechanical highwall scaler, a world first for the mining industry. The scaler will enable open-pit highwalls to be scaled from crest to toe whenever the need arises. It will reduce the risk associated with highwalls and deliver on the Anglo American promise of producing safe, profitable platinum.

Jan 1, 2012

By C. Veloo

"Westmin Resources operates a mine/mill complex at Myra Falls and produces copper and zinc concentrates with minor associations of gold, silver, and lead from a polymetallic, massive sulphide orebody. Mill flotation performance has historically been plagued by periods of uncontrollably high circulating loads leading to low concentrate grades and below optimal tails. This led to a detailed examination of the flotation process. Locked cycle, and pilot plant data are presented. In addition, plant design and commissioning as well as column cell details are discussed. A comparison between actual and predicted performance is also presented. Benefits realized are higher copper and zinc concentrate grades and improved zinc recovery.PrologueMyra Falls Operations is located at the south end of Suttle Lake in Strathcona Provincial Park. Access to the mine site is provided by a 90km paved highway from Campbell River, British Columbia.The mine and facilities are nestled in the narrow Myra Valley between Mount Phillips and Mount Myra. These steep, rugged mountains rise from the valley floor at an elevation of 900 feet to summits of almost 6000 feet. The steep slopes are heavily wooded with fir, hemlock, and cedar up to an elevation of 4000 feet where a transition to alpine meadows occurs. The summits are craggy rock faces, some capped with glacial ice. Myra Creek winds its way through the valley dropping several hundred feet into Suttle Lake. Precipitation is high at over 100 inches per year, which may include up to 10 feet of snow in winter. The temperature may range from 32° C in summer to -18° C in winter.Myra Falls began production in 1965 with the Lynx Mine, supplemented by the Myra and Price Mines in subsequent years, feeding a 950 stpd mill up until the middle of 1985 when the H-W mine was brought into production. The original mill was replaced with a modern 2700 mtpd facility and in 1988 production was increased to 4000 mtpd.Both Lynx and H-W mines are currently in production producing an average of 3650 mtpd. The ore minerals are primarily sphalerite and chalcopyrite, with subordinate galena, bornite, tetrahedrite, and electrum."

Jan 1, 1992

CONTENTS:1. Introduct'iona. Previous Accountsb. Summary of Geologyc. Physiography2. Morgan Groupa. Lithologyb. Structurec. Faulting3. The Mineral Deposita. Descriptioni. Size and Shapeii. Compositioniii. Effects of Oxidationb. Relationship to Structurec. Genesis of Ored. Mount Morgan Orebodye. Sugarloaf Orebody4. Granitea. Mount Morgan Graniteb. Town Granite'c. Moonmera Granite5. Calliungal Beds6. Razorback Beds7. Acknowledgments8. References

Jan 1, 1952

By E. L. Garton

[AnalY3e s of Qany crude t) i 1 s prod.uced in Loui sia.na are incl udeo" in re!Jor~ ~ th'l t have b en u~li shed by the BurOllU 0: i?{ine s. The first rc-port,j} givin..; analyseG of 6 Louisiana crude oils, '-vas pUblluhed in 1921'l.s,nd this was 1'0110\ cd a year later by P.ep rt of InvBstign.tions 21a6t~ givi~ 7 addi tional analyses. The G7even :,ost il'!lportant of these analyses were incol"]lorated in Bulle~in 91,.2, is~ued in 1928. In 1934, analyses of 26 cl ... ude oils j)roduced in southern Louisiana ",ere published ? .§! The present report I)renonts analysos of 72 ad(~itional samples of crude oil frorl 4-, fields in 23 "l)ari shefl in Loui f",io.r]

Jan 1, 1939

By Jouko L. Lehtonen

Sheet pile walls can be sealed watertightly using various methods. The objective of this paper is to introduce a new innovation comprising the use of continuous cement grouting during embedding. The method has been tested on a field test site and installation and permeability features have been observed and analyzed. Installation can be carried out using traditional sheet piling machinery, merely some additional grouting equipment is needed. Installation speed of grouted sheet piles corresponds to that of conventional embedding. The permeability of the tested method is satisfactory in applications where e.g. polluted soil or water has to be isolated from the surrounding environment. In addition, this method can be used for conventional retaining walls where very low permeability is required or for reduction of soil vibration, e.g. close to a railway embankment. The new method to grout simultaneously and continuously during embedding has been developed based on respective innovations on impact driven steel piles.

Jan 1, 2006

By H. W. Gillett, A. E. RHOADS

In its study of methods for reducing metal losses in the non- ferrous metal industry, the Bureau of Mines has conducted a long series of experiments on electric brass melting and collected much data on the experiments of others. Reports bearing on this work that have already been published by the Bureau of Mines are Bulletin 73, "Brass-furnace practice in the United States," and Bulletin 77, "The electric furnace in metallurgical work." A comprehensive report describing the design and operation of all types of electric brass furnaces and showing their performance in experimental tests on a commercial scale is in course of preparation. However, commercial tests of several new and promising types of furnaces are still under way, the results of which should be included in any general discussion of the subject. For this reason it has seemed desirable to issue a preliminary bulletin giving the data on a type of furnace developed in one stage of the bureau's work.

Jan 1, 1918

By W. Abdellah

The purpose of this paper is to establish a qualitative method to estimate the risk level (e.g. rating and ranking) resulting from mining activity. Risk is the product of two factors: probability of failure and cost of consequences. A resultant assessment scale matrix is then used to assign a risk index value which is directly proportional to the potential for excavation instability. A case study, the No. 1 Shear East orebody at Vale?s Garson Mine in Sudbury, Ontario will be examined. A three-dimensional, elastoplastic, finite difference model (FLAC 3D) is presented for a mine development intersection situated 1.5 km below ground surface. The developed assessment scale matrix is used to estimate risk index for intersection (2981) located on 5000 level. The results are presented and categorized with respect to risk-index value, probability of instability, cost of consequence, and mining stage.

Jan 1, 2014

By Edward L. McHugh, Louis J. Denes, Jami M. Girard

A prototype portable hyperspectral imager that operates in the visible and near-infrared ranges of the electromagnetic spectrum was field tested at an open-pit mine. The tests were sponsored by the Spokane Research Laboratory, National Institute for Occupational Safety and Health, as part of an investigation of remote sensing technologies for use in detecting and monitoring conditions in surface mines that could lead to catastrophic slope failure. The spectro-polarimetric imager, built at the Carnegie Mellon Research Institute, employs an acousto-optical tunable filter (AOTF) to control wavelength, a phase retarder to measure polarization signatures, and a digital camera and computer to capture data. The spectral range of the instrument is 450 to 1000 nm at 10-nm intervals. High-resolution hyperspectral images of highwalls, outcrops, hand samples, and drill core were collected in the field. Spectra from the images closely matched those of specific minerals present and were used to classify the images. The field tests were designed to examine the feasibility of using spectral imaging to assist in compiling objective geologic maps of mine highwalls and other hazardous slopes. Results illustrate the capability of the method to discriminate materials within the image, validating the concept of simplified spectral imaging. A contributing factor in many slope failures is the presence and distribution of mechanically incompetent, clay-rich altered rock in slope faces. Spectral features of clays and other minerals are more distinctive in the short-wave and mid-infrared part of the spectrum; the capabilities of the instrument need to be extended into this range to apply the AOTF-based technology to common geologic materials. A field-portable hyperspectral imager could find broad application in remotely identifying diverse materials from solids and coatings to gases.

The Wamum and Idzan Creeks Prospect, located 79km W of Lae, Morobe Province, Papua New Guinea (PNG) was discovered by the exploration arm of Conzinc Riotinto of Australia Pty Ltd (CRAE). The detailed surface exploration and 11 vertical holes drilled by CRAE, combined with the recent work by Highlands Gold Limited, indicate the occurrence of porphyry copper-gold mineral- isation and associated alteration. The prospect occurs within andesitic volcanics of the Middle Miocene Langimar Beds. It is bounded by NE trending faults to the NW and SE. The alteration and mineral- isation is hosted in the andesitic tuffs adjacent to high level quartz diorite and hornblende diorite stocks. A NW trend to alteration and mineralisation is obvious in Wamum and Idzan Creeks. The main alteration type is propylitic with minor zones of potassic alteration. A late sericite-quartz-kaolinite-pyrite alteration overprinted the earlier alteration and mineralisation. Copper and gold mineralisation is related to a quartz-carbonate-chalcopyr-ite-pyrite (¦ bornite) vein stockwork and biotite ¦ K-feldspar alteration. The mineralisation system at Wamum and Idzan creeks is low in total sulphides. It is considered as a high- level fracture-controlled system with limited low grade Cu-Au mineralisation.

Jan 1, 1991

An active list of permissible explosives was published in December 1936 as part of Bureau of Mines Report of Investigations 3324, under the title "Active List of Permissible Explosives and Blasting Devices Approved Prior to July 31, 1936." This list included 170 brand names. Changes in the list that have been authorized to June 30, 1937 placed 35 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Ten permissible explosives were transferred from the active to the inactive list. The present list contains 196 brand names, one explosive having been placed on the list subsequent to June 30, 1937. The brand names of the permissible explosives placed on the active list are as follows:

Jan 1, 1937

By P. J. Petit

Changing mining conditions, legislative issues, rising costs, and the constrained supply of skills and electricity in South Africa, have been some of the criteria forcing mine operators and engineers to review the traditional use of compressed air to power underground hand-held drilling operations in narrow-stope, hard-rock mines. In answering the question, 'What is the best way to power this mine?', they have resorted to trade-off studies with results of limited usefulness, because they are site-specific, and use only a few comparative parameters, based on a small data set. This paper aims to provide definitive, objective, and quantitative decision-making approaches to evaluating alternative energy-delivery systems for stoping in narrow-reef hard rock mines, based on primary and relevant criteria. These include quantifiable criteria such as capital expenditure, operating costs, resulting financial returns, energy and water usage, production performance, life-of-mine, etc. Other important criteria with qualitative aspects are integrated. These are safety, health, and environmental concerns, legislative requirements, business risk, technology change, etc. The paper begins with a review of decision-making processes available, and proposes the use of the analytical hierarchy process (AHP) method as a multiple-criteria decision-making tool and the decision tree based on milestone-driven uncertainties, to validate the selection of the energy delivery system. The results of a multiple-criteria questionnaire completed by a variety of industry experts and professionals, such as production and operation managers, consultants, suppliers, and techno-financial analysts, are discussed. The evaluation indicates the potential for hydropower to be the best solution for narrow-reef hard rock mines, based on current information, mine design layout and production.

Jan 1, 2013

By W. B. Berwald

[Accurate ~cusirc::ie t of euusu.rface r,resw rus £Uld tee:: ?er:~t:,res in producin+ oil and as wells is one of tine ast iy,ulortant steps ever t,.s:en to place the rprwctice of retroleum ,-iroduction on an exact scientific basis. i'reerures and teial.or-tures in a -petrolcuia r4:, rvoir. have a rn..r..ed influence over the o:wvement of oil and ~c s both within the. reservoir and t~:rou,=Ii the various-size "flow otrin;;u" of proLucin,; wells to tine surface. Knovrled: ?c of theso fc,.ctgrs form a Laois for cny attei:ant to [.,-~ly eciantific j:cthods to the solution or analysio of mc.nj proble;ae encountered in the production of oil and 1c_c, Without a.ccur:tc mcaaurx,ients of reosures r:.nd tcn::paratuxes within the rocervoit and -well 'flo-,r strinL:s" tae aI,licution of w.ny proved enbinecrin and scientific princiy-,loo is on %,]

Jan 1, 1935

By E. C. Hoeman, W. C. Stoecker, R. C. Redfield

"INTRODUCTION Industrial sands, characterized by specific physical and chemical proportion, are,essential new materials for the manufacture of glass, sodium siliante and other products. Sands of suitable characteristics are used extensively for molds and cores in the casting of metals as a granular medium in municipal water filters, as abrasives, as traction sand to prevent the slipping of driving wheels of self-propelled vehicles on trucks and in various ceramic and other structural forms. In addition to the use of common silicon sands in concrete, cement, and mortar, special sands find use in sand-lime brick oxychloride cement, and flooring, for coating prepared roofing, and for placing ware in saggers although sand for sandpaper has been mostly displaced by other harder mineral or synthetic grains, other abrasive uses are numerous and include sandblasting stone sawing, glass burnishing and finishing."

Oct 1, 1945

The point of the anode effect on carbon anodes of dcfincd surface area. during electrolytic decomposition of alumina dissolved in molten fluorides. has been determined from current-voltage curves. The reproducibility and accuracy was found to be better for cell voltage than anode current density. Results have been obtained for the effect of alumina concentration temperature and carbon type. The point of the anode effect was strongly dependent on both the alumina concentration and the carbon type. For high alumina concentrations it has been found that the anode effect approaches reversibility. From these results it is concluded that co-evolution of CO, and CF. occurs prior to the onset of the anode effect. The anode effect results when the CF, content becomes sufficiently high for the melt not to wet the electrode surface and is maintained because of the slow desorption of CF, and the high electrode potential that results.

Jan 1, 1967

By H. C. George

This bulletin deals with prime movers, power-transmitting machinery, and the surface equipment and methods used to pump oil wells. It does not discuss geological problems nor the methods and equipment used in drilling or at flowing oil wells. Much of the presentation is by photographs and drawings which are described in the text. Underground equipment and methods for pumping oil wells will be discussed in a later publication of the Bureau of Mines.

Jan 1, 1925