Search Documents

To reduce front-end loader (FEL) collision accidents by detecting obstacles in the rear blind area. The Problem Federal regulations require an audible backup alarm to activate when an FEL is backing. Since the device is constantly being activated, the warning soon becomes a normal part of the mine environment and is less effective as a warning device. Also, when several machines are working together, it is difficult to detect by ear alone just which machine is backing. Approach The Bureau defined the location for hazard detection to include an area extending 15 to 20 ft behind the rear bumper of an FEL. Then, existing surveillance and detection technology was assembled, ruggedness, and applied to the FEL's rear blind area to form a new discriminating backup alarm system employing either infrared light, ultrasonics or radar

Jan 1, 1986

By Cindi Byrns, Andy Davis, Amy Tisdale

The Robinson district, Ely, Nevada is a hydrogeologically complex system with several distinguishable geologic blocks, each with a distinct background groundwater chemistry. To discriminate between background and mine-impacted groundwater, background wells, monitoring wells, pit lakes, waste rock seeps, and surface water samples were analyzed for a suite of major cations and anions, together with trace and precious metals, rare earth elements, 2H-deuterium and 18O/16O. The data allowed identification of groundwater flow paths, verification of hydrochemical source areas and characterization of natural attenuation mechanisms (e.g., mixing, dilution and mineral precipitation) that control the concentration and migration of metals at the site.

Jan 1, 2000

By Andrea Koschinsky, Akira Usui, Michael Bau, Katja Schmidt, James Hein, Thomas Kuhn

Marine ferro-manganese (Fe-Mn) crusts and nodules are metal-rich chemical sediments that are archives of paleoceanographic proxies and potential metal resources and targets of deep-sea mining. Traditionally, crusts and nodules are subdivided into hydrogenetic, diagenetic, and hydrothermal types. While hydrogenetic Fe-Mn crusts are a potential resource for Co, Te, Pt, and REY, nodules are enriched in Cu, Ni, Mo, and Li, and hydrothermal deposits may be enriched in individual metals such as Mo, Ba, and Li, depending on the temperature and composition of the hydrothermal fluid. The different types of marine oxidic Fe-Mn precipitates, therefore, have different economic potential. Hence, a robust classification is not only helpful in the general geochemical characterization of such precipitates (and as such is a useful teaching tool, for example), but may also simplify the evaluation of their importance as a potential metal resource, which helps to prioritize exploration targets for deep-sea mining.

Sep 1, 2014

Eliminate the occurrence of false fire detection alarms caused by the operation of diesel-powered vehicles in underground coal mines. Approach Fire detection systems used in underground mines are based on measurements of airborne combustion products such as carbon monoxide or smoke particles. The effectiveness and credibility of these systems can be reduced by the occurrence of false alarms that result from the operation of diesel-powered equipment, which produces the same combustion products. False alarms end up being very costly to the mine operation in terms of downtime and labor needed for verification. To improve upon current fire detection systems used in the presence of internal combustion engine products, the U.S. Bureau of Mines developed a fire detector that can discriminate between the occurrence of real mine fires and the presence of engine smoke.

Jan 1, 1989

By M Shaffer, D C. Grant, D J. Goudie, P Sylvester, C Voisey

Scanning electron microscope–Mineral Liberation Analyser SEM-MLA can be used to discriminate between hematite/magnetite in iron ores, but achieving backscattered electron (BSE) segmentation between the two minerals is difficult for particles =75 µm using typical preparation and analysis methods for the MLA based on a tungsten filament SEM (Quanta 400) with 25 kV high voltage. Preparing iron ore sample mounts using a slow-speed polishing method, and conducting the experiment on a field emission gun SEM-MLA (Quanta 650) with the high voltage (HV) setting lowered to 15 kV reduces instrument noise and results in very clean BSE images and segmentation. This method requires new X-ray standards to be acquired for each mineral identity at 15 kV because of major changes in the spectra at lower kV. However, once these X-rays are added to the mineral reference list, effective segmentation can be achieved and a proper analysis obtained.CITATION:Grant, D C, Goudie, D J, Voisey, C, Shaffer, M and Sylvester, P, 2017. Discriminating hematite/magnetite via scanning electron microscope–mineral liberation analyser in the - mesh size fraction of iron ores, in Proceedings Iron Ore 2017, pp 541–548 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Kristine L. Pankow, Keith D. Koper, Michael K. McCarter, Jared R. Stein

"The Wasatch Plateau region of central Utah contains a number of active underground coal mines in an area of well-documented natural seismicity. As a result, there are several hundred seismic events recorded in this region every year that may or may not be attributed directly to mining activity. Previous studies have linked the majority of this seismicity to mining activity through various means, but have not attempted to develop a method for categorizing individual events within a seismicity catalog. This study uses both relative relocation and waveform cross-correlation to separate events based on hypocentral depth and waveform similarity, respectively, in the area surrounding a single longwall coal mine within the Wasatch Plateau. We conclude that relative relocation can help with depth discrimination, but there are some unavoidable limitations caused by sparse seismic network coverage. The cross-correlation technique is more promising, with the ability to group events by waveform similarity and track mining progress over both space and time. With cross-correlation based clustering, we confirm that the vast majority (97.6%) of events in the study area are directly related to mining activity, but that a small population of natural seismicity is present as well. Eliminating this natural seismicity from the catalog of seismic events, leaving only those events related to mining, can give operators valuable information about the changing conditions as mining progresses and eliminate concern over events unrelated to mining activity.INTRODUCTIONA number of underground coal mines are located in the Wasatch Plateau region of central Utah, and have been in operation since the late 1800s. This activity has resulted in a well-known history of mining induced seismicity (MIS) (Wong, 1985). Additionally, this area is situated near the border of the Basin and Range and Colorado Plateau physiographic provinces, where naturally occurring tectonic earthquakes also occur (Arabasz et al, 1980). Seismicity separating these physiographic provinces is part of a larger band of seismic activity known as the Intermountain Seismic Belt (ISB) that runs from Montana to Arizona and cuts through the western boundary of the central Utah coalfields (Smith and Arabasz, 1991) (Figure 1)."

Jan 1, 2015

By D. A. Paice, A. B. Shimp

Illegitimate loads on a mine dc power distribution system can be detected by measuring a superimposed ac current. To implement such a scheme, a 10-volt, 3-kHz voltage is applied at each dc power substation. By this means, the mine dc power distribution network, consisting of a feeder and trolley wires with a grounded rail return, is caused to serve also as a 3-kHz ac distribution network.

Jan 1, 1975

By Guangyao Si, Ismet Canbulat, Xun Luo, Yi Duan

Routine analyses of seismicity and event locations are essential for coal burst risk management, especially in the presence of unfavorable and complex geology. In an Australian longwall coal mine, a small-scale seismic monitoring network was installed to monitor a section of a major dyke intersected by the roadway, which was classified as a coal burst prone zone. The Deep Convolutional Neural Network (DCNN) technique was adopted for automatically discriminating seismic events to assess seismicity in this zone. The discriminated seismic events were located with the Shortest Path Method based on the Boundary Discretization Scheme (BDS-SPM) for temporal-spatial seismic event distribution analysis. The results demonstrate that the seismic events are discriminated with an average accuracy of 94%. Moreover, the seismic events are more accurately located using the BDS-SPM with a 3D heterogeneous velocity model compared with results obtained with a homogeneous velocity model. The temporal and spatial variances in seismic activities identify that the rock fractures in the dyke zone are closely related to the longwall mining process and a local dyke has a controlling influence on the stress concentration in its vicinity.

Apr 26, 2022

Contents A-Metal Mining B-Minerals Beneficiation F-Coal

Jan 11, 1951

Contents A - Metal Mining B - Minerals Beneficiation F - Coal H - Industrial Minerals I - Mining Geology L - Geophysics

Jan 11, 1953

MR. LITTLEJOHN: Have you any maximum length that you make your dust barriers? What I mean by that is, your entries are 10 feet wide, and I believe if I remember right, in your single track entries you had only one dust barrier to cover the full width of the. entry in your double track entries, I believe you had two-I would like to know, have you any maximum length you make these barriers? MR. CHAS. LEGER, ROYAL FUEL CO., UTAH: It is stated that they shouldn't be over 8 feet long to obtain sensitiveness. If they make them over 8 feet they are not as sensitive as they should be. They should be made short for two reasons in order to keep the sagging out and to make them as sensitive as possible. MR. DAN HARRINGTON, U. S. BUREAU OF MINES: I didn't come here to enter into any extended discussion on rock dusting or to discuss in particular the situation at Dawson. At the February meeting at Denver, we made a complete study of this matter. Since that time a report was completed and reported to the Phelps-Dodge Corporation and Mr. Moorhead probably has a copy of it, which can give you more complete information as to what we found. We found that with the adobe dusting that they have done, they had six miles of entry pretty thoroughly dusted and of all the samples we took, at least 95 percent of them showed that not only the floor but the ribs and roof were in such a condition that an explosion could not originate in any part of this entry. In other words, this entry as it was dusted was absolutely protected from ignition and propagation. The adobe they used was of material that was non-combustible. In most instances there was not more than 3 per cent of moisture in it.

Jan 1, 1924

MR. GERALD ALLEY (C 11 i e f Draftsman, C. F. & I. Co.) : This invention is primarily intended to correct anything that goes wrong with the fan and any conditions in your air current underground which do not produce a change in your fan water gauge

Jan 1, 1925

THE CHALRYAN.--I think that we have set the stage for the balance of the sym- posium. Most of the emphasis has been placed on the immediate value of every- thing we can do and everything we can learn for the furtherance of the war effort. I believe that ought to be first, but I also believe that this is the time for us to con- sider very seriously not only what these improved methods and techniques do to form a closer approach to ideal segregation but what effect these great quantities of scrap metals and alloys that are going to be produced this year and next, are going to have-what their impact will be-on post- war industry in general and in particular ,, on the primary metals fields. In some cases we have been hearing in the last month or two of the law of diminishing returns coming to the fore. We find alloy simplification growing and certain alloys being produced in great quantities, which will perhaps drop out of the picture some- what as the war ends but never to the lower ( stage they had before. We have I think a pretty good cross- section of the producers, the refiners, the reclaimers and ingot makers, the ultimate users here, and there ought to be some good and helpful discussion. The papers are open for discussion. Mr. Beattie, do you want to make any 1 comment? H. J. BEATTIE.*-To start the discussion I might ask Mr. Deitz what they do with manganese bronze turnings? We segregate the manganese bronze turnings from the other bronze turnings. The value of it seems to be much out of line with the price of ingot, that is, as compared to some of the other alloys like 88-10-2 or 85-5-5-5. I assume it is because they can only use a

Jan 1, 1943

THE CHAIRMAN.-Thank you. Since the papers are rather closely related, I think rather than taking them one at a time we will entertain discussion on any of these problems at this time. W. A. REICH.*-We, of course, quite a while ago got the yellow light that Mr. Cole spoke of, and like everyone else immediately started to study silicon bronzes and brasses. We were interested in the silicon bronzes and brasses because we felt that in order to replace gun metal which makes up a large part of our use we needed something with an elastic limit at least equal to that of gun metal. That means at least 12,000 lb. per sq. in. This study was aimed only at tin conservation. Then we dropped the study of silicon bronzes because high purity copper which is needed in their manufacture became a scarce item. To make a long story short we have recommended to our designing engineers that they use 85-5-5-5 wherever possible because 85-5-5-5 we understand can be made entirely from scrap with little or no tin addition. 85-5-5-5 has a lower elastic limit than 88-8-4, so we felt that we would need another substitute material, a structural alloy with an elastic limit equal to that of 88-8-4, and we immediately turned to the manganese bronze type of alloy. The poor foundry properties of standard manganese bronzes were mentioned by Mr. Thieme and since we feel that high zinc content is largely responsible for this difficulty, our development is directed along the lines of uncovering a material with a lower zinc content and which gains its elastic strength from the addition of other alloying elements, such as, aluminum, manganese and iron. It must be possible to make this alloy entirely from scrap with no additions of scarce high purity material. I would appreciate an expression of opinion on how low we can go in zinc content with this type of alloy without seriously impairing the availability, and how high we can go in aluminum content without making use of aluminum restricted for that use. We assume that the maximum lead content must be placed at 1 ½ per cent to insure good availability and we feel that about I per cent of tin in the alloy would improve salt water corrosion resistance similar to the effect of tin in Admiralty Metal. Has anyone here had experience with the effect of tin and lead on the weldability of such an alloy? C. S. COLE.-What percentage of lead and tin? W. A. REICH.-About 1 per cent of lead and 1 per cent of tin. We are studying the weldability of the alloy but perhaps someone already has the answer. (Pause, no answer) The claim has been made that 1 per cent of lead can be added to certain silicon bronzes without impairing their properties. A silicon bronze with a low zinc content requires high purity copper in its manufacture but if say the 15 per cent zinc, 44 silicon balance copper alloy could be made, with a I per cent lead content, some quantity could be made from scrap. We do not know whether the aforementioned is

Jan 1, 1943

By W. A. Koehler, W. L. Eaton, Reynold Q. Shotts, M. E. Hinkle, M. R. Geer, Ralph M. Hunter, H. F. Yancey, Andrew B. Crichton, E. Zimmerman, S. H. Ash

R. Maize and H. P. Greenwald presiding) E. T. POWELL*-I would like to ask either Mr. Ash or Mr. Eaton if they know of any place where the Mine Inspectors' for¬mula has been used that water has flowed from one colliery to the other. W. L. EATON (authors' reply)-We have made considerable study but we have not gotten around to very many of the barrier pillars. I would not say that any or all of them have been designed to the strict figures of this formula. Most of those ex¬amined will not hold back the water that they are supposed to hold back. E. T. POWELL-If the pillar remains ac¬cording to the Mine Inspectors' formula? W. L. EATON-We have not found very many where the provisions were followed. E. T. POWELL-Where the Mine Inspec¬tors' formula has been fully complied with, have there been failures or not? W. L. EATON-I cannot say. Most of these barrier pillars probably were designed in accordance with this formula, but most of them, if they were so designed, are not in that shape now because a large number of them will not hold back the water; they have been reinforced, and they are punc¬tured in various places. Holes have been driven through them to relieve the hydro¬static pressure to avoid a failure. They do not dare to have a failure. In many instances, the barrier is punc¬tured to avoid a failure. In order to mine their coal safely, many companies must pump water from mines that were aban¬doned many years ago. R. MAIZE-That is true, Mr. Eaton, but do you know of any case where a barrier pillar actually failed and flooded an ad¬joining mine when the pillar had been left in accordance with the Mine Inspectors formula?

Jan 1, 1948

[Contents AH-Metal Mining and Industrial Minerals Pipeline Transportation of Phosphate. (Paper by I. S. Tillotson, R. B. Burt, and J. A. Barr, Transactions AIME, 193, 273; Mining Engineering. March 1952. Discussion by Howard Howie.) 1066 B-Minerals Beneficiation The Effect of Zinc Deleading Operations on Lead-Zinc Selectivity at the Parral and Santa Barbara Mines. (Paper by C. L. Boeke an G. C. Gunther, Transactions AIME, 193, 495; Mining Engineering. May 1952. Discussion by I. M. Symonds, L. H. Lange, Norman Weiss, H. S. Wildman, C. F. Zeuch, E. H. Crabtree.) 1067 Jaw Crusher Capacities, Blake and Single-Toggle or Overhead Eccentric Types. (Paper by D. H. Gieskieng, Transactions AIME, 190, 971; Mining Engineering. November 1951. Author s supplement.) 1069 Screened Ore Use for Fine Grinding at Lake Shore Mines. (Paper by Bunting S. Crocker, Transactions AIME, 193, 499; Mining Engineering. May 1952. Discussion by Fred C. Bond, J. Myers, Norman Weiss, Harlowe Hardinge, Oscar Johnson, L. E. Djingheuzian.) 1069 The Third Theory of Comminution. (Paper by Fred C. Bond, Transactions AIME, 193, 484; Mining Engineering. May 1952. Discussion by Milton C. Shaw and Donald R. Walker; R. J. Russell.)1071 Flotation Rates and Flotation Efficiency.t (Paper by Nathaniel Arbiter, Transactions AIME, 190, 791; Mining Engineering. September 1951. Discussion by Gregoire Gutzeit and Porter Clements.) 1074]

Jan 1, 1952

The Role of the Drilling Contractor BY FERRIS E. SAINSBURY Ron Haxby, Occidental Minerals What is the best method for drilling a 12-in. diam hole to a depth of 1200 ft and maintaining the deflection within 25ft from vertical? Ferris Sainsbury: In order to drill a 12-111. hole down to 1200 ft, In most places you would have to employ a rotary tricone bit With a down-the-hole hammer, I expect by that depth significant Inflows of water would be experienced Even with foams, we would not be able to get the water out of a hole of that diameter So the down-the-hole tricone method of drilling would be best. To keep it straight, we would probably employ the largest square drill stem compatible with the diameter of the hole. Ron Haxby: Is it common in drilling contracts to put in a vertical hole clause? Ferris Sainsbury: You can put in the vertical hole clause Ron Haxby: Does it cost more? Ferris Sainsbury: Normally, if the hole deviates, the driller can correct it with deflection wedges and will charge it back to you at cost, plus 10% or somewhere along that range Any drill hole has a tendency to go perpendicular to the dip, and there are times when stabilization systems are not successful in preventing the hole from turning into the dip of the formation. The only solution, in this situation, is to go in with an oriented wedge and kick the hole back out.

Jan 1, 1979

PRESIDENT LITTLEJOHN: Gentlemen, you have heard Mr. Dyer's paper. The meeting is now open for discussion. MR. NORMAN: I would like to ask the gentleman what is the distance between your crosscuts for the ventilation of rooms and entries in the state of Utah?

Jan 1, 1925

MR. STROUP: As soon as the mine workers realize that machine loading is going to be with us permanently, they will gradually accept the view that they, as well as the Mine Operators, will be in the end better off. Don't you find that to be true? MR. BUTLER: I do find that the antagonistic feeling that prevailed at the start is getting less and less and that the miners are co-operating with us. The machine is going to stay with us and I believe it is going to be better for them because instead of having the hard work of heaving coal, they will merely run the machinery that heaves the coal for them. I believe they all feel that way about the matter. MR. McAULIFFE: Mr. Farnham, out of his professional diplomacy, was very careful not to even mention his own machine by name. I would like to say a word about salesmen and about the men who develop the machines. They are perhaps doing more for the industry than we are doing ourselves. This applies also to the railroad business that I put a great part of my life in. If it were not for the energy, courage, and ingenuity of the men who manufacture machines, we would not occupy the advanced position we do today in the mining world.

Jan 1, 1924

Discussion WEDNESDAY AFTERNOON, FEBRUARY 21, 1951 Ralph E. Grim presiding R. E. GRIM, CHAIRMAN-Has anyone a particularly fruitful point to make or question to ask on any of the papers that have been presented at the two sessions held on Monday and one held this morning? GENESIS OF ENDELLITE T. S. LOVERING-I think we are all a little bit embarrassed when we are asked if we have any particularly fruitful point for discussion; I just have a point. I believe that yesterday Bates said that he had found endellite in only hydrothermally altered rocks-he did not find it in sedimentary rocks-but this morning I heard Victor Allen say something about it as the normal product of weathering, and I am confused. My question concerns the genesis of endellite. I want to know whether endellite is found as a normal product of weathering. I understood from the paper by Bates that it was not a product of weathering and in the paper by Victor Allen* endellite was said to be a product of normal weathering. Did I misinterpret these two papers? T. F. BATES-I did not intend to state or imply that endellite is formed only under hydrothermal conditions. We have been studying the North Carolina deposits extensively and I feel that they illustrate very well the result of normal weathering processes acting on pegmatitic material. The resulting clay seems to be largely endellite or halloysite, almost to the exclusion of kaolinite. I may have misled you in the statement I made toward the end of my talk, to the effect that of all the kaolinic clays we have investigated with the electron microscope, we have not yet found halloysite or endellite in samples from clay deposits that are definitely sedimentary in origin. R. E. GRIM, CHAIRMAN-Professor Allen, have you anything to say on the matter of bauxite?

Jan 1, 1952