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By J. Sjöberg, P. Lundman, E. Nordlund, C. Quinteiro

Abstract In the Kiirunavaara underground mine, crude ore is transported through ore passes from the production levels to the main haulage level. Failure and stability problems have occurred in some of these ore passes, with increasing frequency as mining depths increase. In this paper, selected results are presented from a research project run by LKAB. The presentation focuses specifically on stability analysis. Numerical models were used to identify failure mechanisms, in conjunction with empirical data and engineering judgment. The most important controlling factors governing failure and damage in ore passes were quantified. A causative model was established in which failure mechanisms and failure development were described. This model was used to formulate a prognosis of future ore pass stability, and for recommending remedial measures. Résumé Le transport du minerai entre les niveaux de production et le niveau principal de transport, à la mine de fer de Kiruna, se fait par des passes à minerai. Avec la profondeur d'extraction grandissante, les problèmes de stabilité au niveau de ces passes à minerai se sont multipliés. Les résultats d'un programme de recherche sur la stabilité des passes à minerai à la mine de fer de Kiruna sont présentés dans cet article. Les mécanismes de rupture ont été identifiés à l'aide de modèles numériques, de données de terrain et du jugement empirique des ingénieurs. Les facteurs principaux controllant l'instabilité des passes à minerai ont aussi été quantifiés. Un modèle a été établi dans lequel les mécanismes de rupture et le développement des dommages ont été décrits. Ce modèle a été utilisé à fins prédictives et remédiatives. Zusammenfassung In der Grube Kiirunavaara wird das gewonnene Erz über Sturzschächte von den Abbauebenen zu der Hauptförderebene gefördert. Mit zunehmender Tiefe des Abbaus sind vermehrt Standsicherheitsprobleme in den Sturzschächten aufgetreten, die teilweise zu Verbrüchen geführt haben. In dem vorliegenden Beitrag werden ausgewählte Ergebnisse einer Forschungsarbeit des LKAB präsentiert. Dabei wird der Schwerpunkt auf die Standsicherheitsuntersuchungen gelegt. Zur Ermittlung der Bruchmechanismen wurden numerische Modelle in Verbindung mit empirischen Daten angewendet. Die wichtigsten Einflußfaktoren für das Versagen der Sturzschächte wurden ermittelt. Es wurde ein Modell zur Beschreibung der Bruchmechanismen und des Versagensablaufs aufgestellt. Dieses Modell wurde verwendet, um die Standsicherheit zukünftiger Sturzschächte zu prognostizieren und um Sanierungsmaßnahmen zu erarbeiten.

Jan 1, 2003

By John J. Henn

Ten proposed processes for the recovery of manganese from domestic resources as a high-grade oxide product are described. Nine of the processes employ sulfur dioxide, sulfuric acid, or a combination of both for leaching. The tenth process utilizes sulfur dioxide to sulfatize the ore at 600° to 850°C before water leaching. In addiction to these ten complete processes, six processes from the patent literature are described. Methods for receovering MnSO4?H2O are also reviewed.

Jan 1, 1968

By Fred P. Peters

T. D. Yensen.*—As my information is of a negative nature, I think it belongs under this paper. We are particularly interested in magnetic materials and we would like very much on occasions to make use of powder metallurgy. We have tried repeatedly to use powder metallurgy in preparing our nickel alloys but always. with negative results; that is, we cannot get as good magnetic properties by powder metallurgy as we can by starting with a molten material. We have tried by all possible means to make materials' like 50 per cent iron-nickel alloys by powder metallurgy. The compacts can be regularly lorged and rolled but no matter what we do in the way of annealing, the magnetic properties come out very much poorer than if we start with molten material. F. V. Lenel. †—I want to mention one characteristic of articles made from metal powders which distinguishes them from die castings; that is, their wear resistance. Die castings usually are made from zinc or aluminum alloys and a few copper-zinc alloys; all of them are comparatively soft and not very wear resistant. I know of a number of cases where powder metallurgy rather than the die-casting method was used for producing a certain part because higher wear resistance was needed than could be attained in die castings. A, J. LanghammeR.*—The subject of powder metallurgy is somewhat difficult to discuss, and portray, in the time that his been allotted. Most of you would rightly be bored if we went into details. However, I will cite one incident that possibly will help illustrate some of the potentials. Last summer I was in Washington and met Navy officials for the purpose of studying the possibility of making a certain part by powder metallurgy. The part is highly intricate and I happened to remark that the material cost would be high; that is, the cost on one raw material. Promptly a high-ranking Navy officer said: "Mr. Langhammer, if you must pay x dollars a pound for the raw material, but achieve the desired results, the cost of the finished part would still be low."

Jan 1, 1945

AALL, Christian H.,(M'49), Asst Res Dir Monsanto Chemical Co Anniston, Ala AALSETH, Earl P ,(J,51), Amerada Petr Corp Geological Dept Williston N Dak AAMOT, Olav Crone, (M'29), Met Pacific N W Alloys, Inc , Box 6215, Hillyard P 0 Spokane 14, Wash AARING, Floyd D ,(J'48), Petr Engr P 0 Box 130, Calgary, Alta Canada AARCNSON, Hubert Irving, (S'47), Carnegie Inst of Tech., Pittsburgh, Pa ABADIE, Henry G ,(M'43), Asst to the Sup- of Operations, Long Beach Oil Development Co ,255 So Santa Clara Ave Long Beach, Calif ABBISS, H. J., (A'50), Min. Engr., Buchans Mining Co., Ltd.. Buchans, Newfoundland ABBOTT, Clarence Eugene, (M'04), 901 Insurance Bldg , Raleigh, N C ABBOTT, George, (S'52), Mass Inst of Tech Cambridge, Mass

Jan 1, 1952

This Spotlight gives a brief summary of the proposed 1991 tax amendments of relevance to mines and mining houses. It should be read together with the author's article South African mining tax in the 1990's', which appeared in the August 1990 issue of this Journal. A number of tax amendments of relevance to the mining industry were proposed by the Minister of Finance in his March 1991 budget speech. In addition, certain other measures that may be implemented were set out in the budget review document released at the same time. A word of caution is necessary: these measures will become law only if and when they are enacted in the appropriate legislation. When this legislation is tabled in June, it may not contain all of the measures discussed below, some of the measures may appear in modified form, and other measures not discussed at the time of the budget may well appear. Unless otherwise stated, the 1991 tax amendments will affect companies with years of assessment ending in the twelve-month period to 31st March, 1992.

Jan 1, 1991

The first record of coal discovery in Australia dates back to 1791 when escaping convicts found coal in the banks of a creek just south of Newcastle. Development in the Newcastle Coalfield was the sole source of supply for the colony and for export until the 1850s when mines were established in the Southern & Western Coalfields. The important Hunter Coalfield was not discovered until 1873 when coal was found at Rixs Creek near Singleton: The first exploration drillholes were commenced in 1799 using drilling equipment obtained by Sir Joseph Banks. From 1820 to 1850 several famous geologists (naturalists), including the Rev W. B. Clarke, J. D. Dana and Strzelecki, wrote reports on the coal measures in New South Wales. The first Government Geo- logist, Samuel Stutchbury, was appointed in 1850. The major coal deposits of the State are contained in Permian Coal Measures in the Sydney-Gunnedah and Oaklands Basins. Coal quality ranges from high volatile, high moisture thermal coal at Oaklands to low volatile hard coking coal in the Southern Coalfield. Most coalfields can provide a range of steaming and coking coals.

Jan 1, 1988

By Benjamin C. Craft

As predicted, during 1937 South Louisiana witnessed one of the most active drilling campaigns in the history of the area, resulting in the discovery .of 14 new fields. The economic importance of 10,000-ft. production was far-reaching and the objective depths placed on some wildcats was 12,000 feet. Most of the important discoveries and deep tests were in the delta area between the Atchafalaya and Mississippi Rivers, where the upper Miocene sands were found productive between 10,000 and 11,000 ft. The casing program on these wells usually called for a protection string of 95/8-in. casing at approximately 9500 ft. Drilling barges with the heaviest equipment were used where water transportation was available. The oil production for South Louisiana during 1937 was 62,147,690 bbl., as compared with 51,968,727 bbl. during 1936, an increase of 19.5 per cent. There were 281 oil and gas wells and 172 dry holes completed during 1937 as compared with 262 oil and gas wells and 135 dry holes during the previous period. New Fields Gibson.—The first discovery for the year was in the Gibson area, where Shell Petroleum Corporation's Realty Operators No. 1, sec. 18, 17 S., 15 E., Terrebonne Parish, was completed flowing 780 bbl. of 38° A.P.I. oil daily through a 14/64-in. choke with a tubing pressure of 1700 lb. Production is from upper Miocene sand found from 9461 to 9483 feet. Abbevil1e.—The discovery well for the Abbeville field was Continental Oil Company's Hebert No. 1, sec. 20, 12 S., 3 E., Vermilion Parish, completed flowing 50 bbl. of distillate and 2 million cubic feet of gas through a 3/16-in. choke with a tubing pressure of 2550 lb. The well was plugged back from 12,216 ft. in the Chickisawhay, and is producing through perforations from upper Miocene sand found from 7668 to 7682 ft. Later in the year, the same operators completed Brookshire No. 1, sec. 66, 12 S., 3 E., flowing 366 bbl. of 42° A.P.I. oil per day through a 3/16-in. choke with a tubing pressure of 1800 lb. This well was com-

Jan 1, 1938

By W. H. Young

In response to increasing national energy requirements. highlighted by the continuing growth in demand for coal for the generation of electric power the output of bituminous coal and lignite in 1965 passed the 500-million-ton mark for the first time since 1956, thus emphasizing the steady up-ward trend from the recent low of 403 million tons in 1961. There were corresponding upward trends in consumption, exports mechanization, and productivity. Production.-The output of bituminous coal and lignite in the United States in 1965-512 million tons-was 5 percent greater than the 487 million tons produced in 1964. The gain was attributed largely to expanded consumption by the electric utilities, greater use at coke ovens, and an increase in exports.

Jan 1, 1967

By Z. Hou

ABSTRACT: Short-term strength, damage and healing boundaries for rock salt are experimentally determined and integrated into the Hou/Lux-MDS damage-healing model. This model can be used to describe the mechanical behaviour of rock salt during a damaging process (under high stress to strength ratios) as well as during a healing process (under very low stress to strength ratios with high confining pressure). The development of the damage and the stress to strength ratio in the excavation damaged zone (EDZ) of a storage cavern under a minimum internal pressure as well as the development of the healing of damage and the stress to strength ratio under a subsequent maximum internal pressure are investigated project-related. The results of the investigation make it possible to shift the permissible minimum pressure boundary down, allowing the optimisation of decisive economic characteristics of storage caverns. RÉSUMÉ: Le comportement court terme, l’endommagement et les conditions de colmatage pour le sel gemme ont été étudiés expérimentalement et intégrés dans le model endommagement-colmatage Hou/Lux-MDS. Ce modèle permet de décrire le comportement mécanique de sel gemme pendant le processus d’endommagement (sous fort rapport contrainte-résistance) et le comportement du processus de colmatage sous très faible rapport contrainte-résistance avec forte pression de confinement. Le développement d’endommagement et le rapport de contrainte-résistance dans une zone d’endommagée (EDZ) d’une cavité de stockage avec un maximum de pression de soutènement ont été étudiés. Les résultats de cette étude permettent de conclure qu’il est possible de baisser la pression de soutènement, et par conséquent d’optimiser les caractéristiques économiques décisives des cavité de stockage. ZUSAMENFASSUNG: Für Steinsalz werden Festigkeits-, Schädigungs- und Verheilungsgrenze experimentell ermittelt und in das Schädigungs-Verheilungs-Modell Hou/Lux-MDS integriert. Damit kann das mechanische Verhalten von Steinsalz sowohl bei einem Schädigungsprozess (mit hohen Ausnutzungsgraden) wie auch bei einem Verheilungsprozess (mit niedrigen Ausnutzungsgraden) beschrieben werden. Projektbezogen werden die Schädigungs- und Ausnutzungsgradentwicklung in der Auflockerungszone einer Speicherkaverne unter einem minimalen Innendruck sowie die Verheilungs- und Ausnutzungsgradentwicklung unter einem anschließenden maximalen Innendruck untersucht. Die Untersuchungsergebnisse erlauben, die zulässige Minimaldruckgrenze nach unten zu verschieben, so dass entscheidende wirtschaftliche Kenngrößen von Speicherkavernen optimiert werden können.

Jan 1, 2003

By E. A. Holbrook

MINING Metallurgy, and Petroleum Engineering department in our colleges are facing a crisis; indeed, conditions that threaten their very existence. Unless the Army, Navy, and War Manpower Commission change their present policy, within two years mineral industries education as now carried on will die, because no ablebodied students will be left in the course. If this is the decision of our responsible governmental agencies we of the mining schools must perhaps accept it as a war measure. It might be well however, for the executive of our mining metallurgical, and oil companies to look ahead a, to where they are to recruit a supply of young technically trained engineers. You can no more operate a mine, a steel plant or an oil company without trained engineers than you can operate a battleship without mechanical and electrical engineers.

Jan 1, 1943

In 2005, data obtained from the Mine Safety and Health Administration (MSHA) indicated a total of 922 underground (6.3%) and 13,744 surface (93.7%) mining operations.1

Jan 1, 2008

By P. Duwez, L. Zwell

L. S. BUSCH—We have had presented two methods of measuring these variations in powder compacts. E. OROWAN—Tn connection with the rolling mill research work carried out at. the Cavendish Laboratory, Cambridge, with the help of the British Iron and Steel Research Association. Dr. E. A. W. Hoff, Mr. J. Los, and myself, have determined coefficients of friction at ex- treme pressures for a number of liquid and solid lubricants, both by direct measurement, and by calculation from measured values of the roll force. The most efficient lubricants at these high pressures (for the small amounts of sliding that, occur in rolling) were camphor and. in particular, borneol (Borneo-camphor). Perhaps such lubricants could be used with advantage in the kind of work described by Dr. Wulff. L. S. BUSCH—1 think Dr. Wulff has in the past mentioned experiments which have been performed in the extrusion and rolling of metals and which led to conclusions which can be applied to the compacting of metal powder. A. SQUIRE*—There have been some recent developments in the field of high pressure lubricants which indicate that boron nitride might be a very desirable material to employ as a die lubricant. At the present time its cost is prohibitive, but as the need arises for the material it will undoubtedly come down in price. The present price is $200. a pound. It is my understanding that one of the reasons for vacuum pressing both in ceramics and metal powders, is to prevent

Jan 1, 1950

By L. Nahai

COAL, salt, lapis lazuli, and construction materials such as lime, gypsum, slate and stone were the only mineral commodities produced in Afghanistan during 1963. Beryl has been produced sporadically. Small deposits of chromite and lead-zinc are known but remained unexploited because there were no domestic markets for the two commodities and transportation costs from Afghanistan to world markets were too high. Oil fields of sufficient magnitude to justify exploitation have not been discovered, but known natural gas reserves are substantial and have potential significance. There is evidence of large high-grade iron ore resources, but these are in an unfavorable location. The contribution of the mineral industry to the economy was small, although precise figures are not available. The reported value of mineral production in 1963 (excluding barite) was 181.6 million afghanis (about US$4 million). Employment in the industry, including cement plants and quarries, was estimated to be no more than about 2,000.

Jan 1, 1964

By Donelson A. Robertson

Literature was searched and cases of alleged water well damage were investigated. Occurrence of ground water in Appalachia is primarily in low yield, fractured, water table aquifers. Four test sites were chosen based on geographic and geologic diversity. Test wells were drilled at each site and base line data on water quality, static water level, and drawdown characteristics were obtained before surface mining commenced. Blast induced ground vibrations were measured at the surface by the wells at levels up to 5.44 inches per second maximum resultant particle velocity. Measurements made at the bottom of wells indicated that vibrations were considerably attenuated at depths of 140 to 160 feet. No direct evidence of change in water quality or well performance was produced by blast vibrations, but removal of downslope support by excavation does cause lateral stress relief which permits the water-bearing fractures to become more open. This additional storage capacity causes the static water level to drop and for well-bore permeability to improve. Static water level recovers if sufficient recharge is available and well performance is

Jan 1, 1980

By Porfirio Pinto Linares

El presente texto señala la paragénesis y mineralización del distrito de Morococha. Dicho distrito está situado al Este de Lima, en el Perú central y sus principales productos minerales son el cobre, zinc, plomo, plata. Su mineralización está relacionada con el intrusivo del mismo nombre, encontrándose el centro más efectivo de la mineralización en el stock San Francisco, mientras que la paragénesis observada en las estructuras estudiadas es compatible con el zoneamiento existente; ya que las primeras capas depositadas son de cuarzo y pirita, siguiendo la esfalerita, enargita, calcopirita, tetrahedrita, esfalerita y galena; rellenando las cavidades se encuentran los carbonatos.

Mar 1, 1965

By Gerald R. Smith

Because of continuing concerns regarding the effects of cumulative quantities of materials in the environment, the Bureau of Mines has initiated a series of studies to evaluate, to the fullest extent possible, all aspects of the materials flow sequence fur selected commodities. Although tungsten and its compounds do not pose a significant health hazard to the environment, they do represent valuable resource materials to which appropriate conservation considerations must be given. The present study includes a description of recent trends in the consumption, loss, and recycling of tungsten-containing materials in the United States during the period 1974 to 1991 and an estimation of the cumulative loss of tungsten to the environment since 1910. Obsolete tungsten is recycled primarily as cemented tungsten carbide components that have been used in cutting and wear-resistant applications. The quantity recycled, as a of annual U.S. consumption of tungsten, was estimated to have increased from 10% in 1974 to 341a in 1991. An estimated 58% of the 148,000 metric tons of primary tungsten consumed since 1910 was lost to the environment through means such as dissipation, discard, and dilution.

Jan 1, 1994

By Thomas C. Poulter

Abstract The Poulter seismic method of geophysical exploration is an attempt to obtain an increased efficiency in the conversion of the energy of an m~pl06ion into useful energy which has directive properties and which contains a minimum of random frequency and random phase relations. Very little effort has been made in the past to simplify OT even control the uniformity of the seismic energy being introduced into the ground. The Poulter seismic method is also an attempt to improve the signal-to-noise ratio not merely by trying to complete the impartial filtering done by the earth on ,the continuous spectrum of primarily high-frequency energy radiated from a shot point but by applying a frequency control at the point of origin of the seismic wave. The energy from a shot-hole charge is peaked in a frequency which is much higher than will be transmitted through the ground, and its absorption introduces background interference. Only 10 to 20 per cent of the seismic energy of a shot-hole charge .is directed downward in a 90-degree vertical cone, whereas, from a pattern of charges detonated above the surface of the ground, 85 per cent of the seismic energy is included in a 90-degree cone and in some cases it is even confined to as small as a 30-degree cone. This greatly reduces the horizontally distributed energy, thereby producing a marked improvement in the signal-to-noise ratio. The frequency of the signal energy may be peaked in a rather narrow range by the proper application of two or more impulses upon the surface of the ground controlled as to direction, magnitude, and timing. These impulses may be controlled by the reflection shock wave technique, the pressure pulse technique, and the sequence firing technique, using the primary controls as outlined. The information obtained from the study of directivity of seismic energy in a high velocity, uniform material such as the ice on Taku glacier, in the Juneau ice field in Alaska, has been of great assistance in the application of the method to oilfield and mining problems.

Jan 1, 1950

By Ródnei Abbade Abreu

A UPV é abastecida basicamente por duas fontes de energia elétrica de 60 Hz (maioria das cargas da usina): LIGHT (concessionária - externa) e CTE#2 (interna). A energia externa chega a UPV via sistema de transmissão e distribuição da LIGHT, por esse transporte paga-se uma tarifa de uso do sistema para a concessionária, vale ressaltar que não é comprado energia da LIGHT e sim o transporte da mesma, a energia é comprada de unidades geradoras distantes da UPV. O valor pago pelo transporte da energia é baseado em um contrato de Demanda [MW], que representa um valor máximo que o sistema deve ser capaz de suportar, caso seja solicitado. O objetivo desse trabalho é identificar qual a melhor (menor) demanda a ser contratada pela UPV, de forma a atender os processos produtivos e não ultrapassar o valor contratado (pagamento de multa), para tal foi criado um simulador com base em dados históricos para estimação de demanda a ser contratada pela usina.

Jul 31, 2018

By Chaoxun Zhao, TAIYOU LI, JIAQI JIN, Jan D. Miller, Chen‑Luh Lin

A large portion of the energy consumed in copper concentrators is used to reduce the particle size of the feed by crushing and grinding. The cost of metal production could be reduced if low-grade particles of cm size were removed prior to further processing. Two copper sulfide ore samples (3 × 1 cm) from Arizona were analyzed by micro X-ray computed tomography (Micro-XCT) to determine the grade of copper sulfide in each particle. For copper ore sample A, a significant number of particles contained very low amounts of copper, while some particles had copper sulfide grains of mm size. Based on Micro-XCT, it was expected that 85% of the copper for sample A could be recovered at 65% of mass rejection during preconcentration by sorting. However, in sample B (a different copper ore), distribution of copper sulfide was dispersed primarily in each ore particle, so for the particle size class of 3 × 1 cm, liberation of copper sulfide and gangue minerals was not significant. In view of the XCT results, dual energy (DE) X-ray radiography was used as a basis for sorting. Previous DE X-ray radiography of a drill core sample demonstrated that this rapid detection method can be used to identify rich or poor Cu-bearing coarse particles. Pilot scale X-ray sorting of sample A (10 × 1 cm) showed 31% rejection of a 0.08% Cu gangue product with a corresponding recovery of 90% copper.

Nov 30, 2021

By J Rubio

This work presents design features of an innovative in-line mixing helical (coiled) reactor for flocculation and flotation as a solid-liquid separation process for suspended particles (including liquid droplets). The device has been named flocs generator reactor (FGR), a compact system whereby the flocculation of particles is assisted by the kinetic energy transfer from the hydraulic flow through the reactor and/or by the injection of microbubbles (30 - 70 ¦m). The flow mixing presented a plug flow regime with a low dispersion degree, promoting the required hydrodynamic conditions to disperse the polymer flocculant (cationic polyacrylamide) and to generate æstrongÆ flocs of Fe(OH)3 or clays (as colloidal model systems) with aggregation using an anionic polymer, Al2(SO4)3 and poly aluminium chloride (PAC), and oil emulsions destabilisation with a high molecular weight cationic polymer. The solid-liquid separation of the flocs was then achieved either by settling or by flotation with microbubbles. This paper discusses advances in this new in-line flocculation-rapid flotation device to remove æaerated aggregatesÆ, aggregates with entrained and entrapped bubbles. Studies were carried out with different models of FGRs (varying the length:volume ratio) and process efficiency (mainly kinetics) evaluated as a function of polymer concentration and some operating parameters, namely, feed flow-rate, air:solids ratio and residence time. Results showed that the aerated flocs are readily floated with rising rates in the order of 120 mh-1, values higher than those obtained for the settling of the non-aerated flocs (18 - 24 mh-1). The FGR requires short residence times and generates dense, well structured flocs (with a mass fractal dimension, dF of about three) which withstand high shear forces. Mechanisms involved appear to include small bubble formation and their rapid occlusion (entrapment) within flocs, nucleation of bubbles at floc/water interfaces, polymer coiling as a result of æsalting outÆ effects at the aqueous/air interface and plug flow type of mixing (flocculation). Successful examples of emulsified oil and solids removal from water are shown and because in all cases high efficiencies were obtained (>90 per cent removal). Due to the high process efficiency and high loading capacity shown, the FGR appears to have good potential as an in-line flotation-separator device in applications requiring high rate solid-liquid or liquid-liquid separations.

Jan 1, 2005