Search Documents

By W. W. Adams

"The seventh National Safety Competition, that for 1931, conducted by the United States Bureau of Mines, was participated in by 350 mines and quarries operating in 34 States. Tables 1 to 5 show the relative standing of the various plants, Bronze trophies, known as the ""Sentinels of Safety,"" which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines were awarded to five companies, each company having established the best accident—prevention record within one of the five classes into which all companies were divided — namely, anthracite mining companies, bituminous—coal mining companies, metal—mining companies, operators of nonmetallic mineral mines other than coal mines, and quarries or open—cut mines. The trophies are awarded for one year and are then transferred to the winners of the succeeding year's contest.The outstanding feature of the contest of 1931 was the operation of a bituminous coal mine without a lost—time injury to any employee. While accident—tree records had previously been made by certain quarries, metal mines, and nonmetallic mineral mines, never before has such a feat been accomplished by a bituminous coal mine in the National Safety Competition. Whether or not such a record has been made by a bituminous—coal mining company not enrolled is the competition the writer does not know, but it is believed that the case referred to is unique among large coal—mining companies. The mine to which reference is made is No. 1 mine of the Phelps Dodge Corporation, at Dawson, N. Mex. To that company belongs the distinction not only of being the first coal—mining company among those enrolled in these yearly safety contents to operate its mine without an accident but also of occasioning the 'Sentinels of Safety' trophy for a bituminous mine to take its first journey west of the Mississippi River. For the past six years the trophy has been in West Virginia, Alabama, or Pennsylvania."

Jun 1, 1932

By Mark N. Savit

It is indeed a rarity for a non-engineer, let alone a lawyer, to even be considered for a mining-related award, especially where that award is for significant contributions to technical progress in the mining and exploration sectors. So, when I was notified that I had received this award, I struggled for a topic that would meld the legal world that I operate in with the engineering driven world of exploration and extraction. The most exciting part of my job has always been the opportunity to absorb the technical details of the cases I work on and, in effect, translate them for a lay audience. Too often, I have found, lawyers, judges, legislators and yes, even regulators who lack a technical background simply give up trying to understand the details of the very conditions or processes that they are trying to describe and simply repeat phrases told to them by their client or by a retained expert.

Jan 1, 2008

Ultrasonic Extinction for High Resolution Particle Size and Concentration Analysis

Sep 13, 2010

By S. M. Shelton

Ferrograde manganese ore or its equivalent is essential to the manufacture of every ton of steel produced; although it is well-known that there are largo deposits of low-grade ore in the United States, production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stock piled ore is depleted through inability to obtain adequate supplies from foreign sources. Consequently, a program of laboratory and pilot-plant investigations designed to solve the problem of obtaining a domestic supply of manganese has been undertaken by the Metallurgical Division, Bureau of Mines. This paper is one of a new series that will include reports of results obtained in the various investigations conducted under the manganese program. The scope of the program and the organization that was set up to direct and supervise the work were discussed in the foreword of the first paper of this series, Report of Investigations 3506, Manganese Investigations 1. Concentration of Manganese Ores from the Drum Mountain District, Utah, by S. R. Zimmerley, J. D. Vincent, and C. H. Schack. Other reports will be published as the work progresses.

Jan 1, 1942

By J. Kempken, T. A. Schreiter, R. Degel, H. Schmieden

Keywords: Pyrometallurgy, SMS Demag, Germany, submerged arc furnace, ferro alloys, non-ferrous, FeCr, FeNi, FeMn, copper, cobalt, slag cleaning, PGM, rectangular furnace After a short summary of the SMS Metallurgy part of the SMS group, the paper will focus on Submerged Arc furnace technology. After general aspects of furnace design, the focus will shift to different applications and their specific furnace requirements. Finally, a state-of-the-art design tool as well as a new invention to improve slag-cleaning technology will be featured.

Jan 1, 2006

By C. O. Lee, Z. W. Bartlett, R. H. Feierabend

The Grand Isle sulfur mine is located in the Gulf of Mexico, approximately seven miles off the coast of Grand Isle, Jefferson Parish, La. The deposit is on acreage covered by oil, gas, and mineral leases originally issued in favor of Humble Oil & Refining Co. by the State of Louisiana which were continued, maintained, and redesignated by the U.S. Department of the Interior after passage of the Outer Continental Shelf Lands Act. The sulfur deposit was discovered in 1949 when Humble Oil & Refining Co. penetrated more than 200 ft of sulfur-bearing limestone in a zone between 1813 and 2075 ft below sea level. In 1954, Humble drilled ten more sulfur prospect holes, eight of which encountered sulfur ore. On September 19, 1956, Freeport Sulphur Co. acquired from Humble Oil & Refining Co, the sulfur rights underlying the tracts, and the actual design of the installation began the same month. The first structural contract was awarded in December 1957 and offshore erection began in June 1958. The initial phase of construction has been completed and production by the Frasch process commenced in April 1960. The estimated total cost of the project is $30 million, of which $8 million is the extra cost incurred by the necessity of offshore operations. More than $22 million was expended before production was started. GEOLOGY OF DEPOSIT Grand Isle is the third largest sulfur deposit in the U.S. The orebody embraces several hundred acres, but its outer limits are yet to be defined to the northeast, east, and south. Most Gulf Coast sulfur deposits occur in a caprock mantle of calcite (referred to as limestone), anhydrite, and occasionally gypsum, which covers the apex of an intrusive mass of salt. Commercial quantities of sulfur are usually confined to the calcite or limestone member. Most often such limestone is completely enclosed by dense anhydrite below and impervious sediments above, which effectively form a closed reservoir. The depth of the Grand Isle orebody ranges from 1800 ft to 2500 ft below sea level. Within the present boundary, the sulfur-bearing limestone varies in thickness from 220 ft to 425 ft, while the sulfur content varies an average of about 15 pct in the leanest hole to an average of about 30 pct in the richest. Rock containing less than 5 pct sulfur is not classed as ore, and holes assaying less than 20,-000 long tons per acre of sulfur in place are not considered commercial offshore. The sulfur enrich-

Jan 1, 1961

By Paul Krivokuca

Outline Quinsam Coal Mine ?? Location ?? Mine History ?? Safety ?? Production ?? Hiring 4S Mine ?? Depillaring design ?? Structural mapping, Risk assessment ?? Rock Bolt Design Selection ?? Training

May 1, 2008

Operations of the new copper smelter at Mount Isa commenced on the 6th February, 1953. Prior to this date a paper by R. V. Anderson (1953) outlined the smelter layout, proposed operation and expected performance.Nominally a 50-ton per day plant, output is currently at the rate of 85 long tons per day. In the first 3t years, of operation to 30th June, 1956, '71,339 tons of blister copper were produced. Operation has been stabilized' and a number of modifications to plant and operation have been made. This paper reviews the progress made to date.GENERAL LAYOUT AND EQUIPMENTThe general layout and equipment follows well-established practice as study of Figs. 1 to 4, and Appendix II will show. This diagrammatic representation of layout (Fig. 1) and flow sheet (Fig. 2) is intended for the purpose of brevity to take the place of a detailed plant description.Choice of site for the smelter was limited by the necessity for close proximity of the waste heat boilers to the powerhouse.Much excavation was necessary before foundation work commenced, but the plant is compact and further expansion is possible.CHARGE MAKE-UPRoaster charge initially comprised concentrates, purchased ores, revert materials, mine sulphide ore and barren sand. As purchased ore receipts increased and as domestic black rock oxidized ore became available, the latter two fluxes were eliminated from the charge. Fluxes at minus i-in. sizing are trucked from crushing plant or stockpile by motor lorries. Filtered mill concentrates are dropped from an overhead conveyor on to the storage patio floor adj acent to the two concentrate bins.

Jan 1, 1957

A discussion on simulation tools to aid the development of robotics platforms is presented. The focus of the work is towards mining robotics platforms where operations are typically in unstructured, unpredictable environments and a high degree of dependability in their operations is required. It is argued that a test-based development approach leads to more robust solutions and faster development cycles than traditional single-track field-only development and that the key enabling technology for this development paradigm is the judicious use of simulation tools. The future direction of simulation for use in online applications such as active planning and as a means to assist tele-operation in high latency communication applications is also brief y considered together with the requirements for a useful simulation environment in terms of the simulator architecture. Finally, a case study is presented on the application of the discussed methodologies to an unmanned ground vehicle (UGV) for earth-moving tasks, which is being developed in an accelerated time frame with a transient development team.

Dec 6, 2010

Behaviour of Bubble Clusters in a Turbulent Flow

Sep 13, 2010

Kudremukh Iron Ore Company Ltd, a wholly owned Government of India Enterprise, was established in the year 1976 to develop mine and plant facilities to produce 7.5 Mtpa of high-grade iron ore concentrate at Kudremukh. The mine and plant facilities were commissioned in 1980. In view of high demand for iron oxide pellets in iron and steel industry worldwide and as a diversification activity, a pelletisation plant of 3.0 Mtpa capacity was commissioned in the year 1987 at Mangalore for production of high-quality blast furnace and direct reduction grade pellets for export. The pellet plant capacity has been increased to 3.5 Mtpa by technological improvement which included installation of roll press for quality and productivity improvement. In addition, the pellet capacity is being increased to 4 Mtpa by the addition of Shaft Pelletising Furnace plant.

Jan 1, 1999

A commercial Philips X-ray Fluorescence (X.R.F.) analyser was converted to an experimental instrument suitable for determination of the accuracy to be expected of X.R.F. on line analyses of concentrator slurries. Problems with stability of slurry sample presentation were eliminated by a number of minor modifications.By the use of multiple linear regression techniques instrument calibration equations including error terms were determined for copper flotation feed slurries. Results indicated that the accuracy of copper and iron analyses of flowing slurry samples could approach that of static pressed powder samples.Possible means of reducing the error terms to a level of at least that of pressed powdel' samples involve alternative methods of compensating for the per cent solids in the slurry, Design is under way for installation of a plant unit.

Jan 1, 1968

By Manuel Rapiman, Ricardo Sepulveda

The feasibility study of Escondida Norte (ENorte), recommended a slope angle design for the Final Pit. But, according to the experience obtained with the slope adjacent to the West wall of ENorte, in which Compañia Minera Zaldívar (CMZ) gained in its phase 4, a slope of similar geotechnical characteristics will be exposed in the West Wall of Phase 1 (Premine) and of the Final Pit, with an interramp angle 53º and with very good stability results. In this regard, Minera Escondida Ltd. (MEL) performed a study of the slope angles for the phases mentioned and according to this delivered the results of this evaluation, the recommendations and/or the necessary conclusions in the design to ensure that the slopes are stable enough and may enable safe operational management of them.

Jan 1, 2006

By Christopher J. Bise

INTRODUCTION The principal means for transporting men, supplies, and mined material in an underground or surface mine are rail systems, conveyor belt systems, or a combination of the two. Typically, large underground mines use rail haulage from the mining sections to the hoist, with conveyor belts being used within the sections. Small mines use conveyor belts in the mains and sub- mains as well as in the panels. The size and layout of surface mines also contribute to variations in the way these haulage systems are applied. The following sections address the typical problems confronting mining engineers in designing these haul- age systems. For rail, these include rail selection and turnout design, locomotive tractive-effort calculation, and motor sizing. Belt haulage calculations include belt width and speed specifications, tension and take- up requirements, idler spacings, and motor sizing. TRACK LAYOUTS Introduction The adequacy of mine track layouts is dependent upon such factors as rail weight (Table l), suitable ties, a well-drained roadbed, and properly designed curves, grades, and track alignment. As long as the installation conforms to the manufacturer's recommendations, good service can be expected from the rail system. Typically, mining-engineering calculations for rack layouts have dealt almost exclusively with the design of turnouts. As such, the following section provides the necessary information for computing the theoretically correct dimensions of turnouts. Turnout Design Fig. 1 shows a typical turnout with an identification of the component parts. Fig. 2 identifies the variables that are used to determine the turnout dimensions. The formulas that concern the mining engineer are those listed: [ ]

Jan 1, 1986

By J. Dahner

Total milling cost is composed of energy, liner and grinding media costs. In primary high ball load milling, the grinding media play the biggest role in total milling cost. This cost can be drastically reduced by improving the impact condition inside the mill. The impact condition inside the mill is influenced by shell liner design (as well as feed end and discharge design) and the type of discharge. The improvement of the impact condition will result in a significant decrease in grinding media consumption. The softened impact condition allows for better alloy optimization, resulting in a further reduction in grinding media consumption. Optimized liner design can also improve energy consumption as less energy is wasted in the projection of the grinding media. Magotteaux utilizes tools to simulate and show the grinding media trajectories for shell and end liners. This paper will present some practical examples where the media and energy consumption can be or has been reduced by optimizing liner design. Keywords Comminution, grinding, liner design, grinding media wear.

Jan 1, 2011

By Natalia Konstantinova, Georgy Novikov, Pavel Rekant, Goergy Cherkashov, Olga Bogdanova

The economic interest of oceanic ferromanganese crusts and nodules is determined by high grades of major, rare and earth rare elements in these types of marine minerals [1]. Modern oceanic ferromanganese deposits have a global distribution with the largest fields in the Pacific Ocean. The Arctic Ocean still remains a poorly explored region. The first ferromanganese deposits from the deep part of the Arctic Ocean were recovered almost at the same time in 2012 both in US and Russian cruises to the Chukchi Borderland (1) and Mendeleev Ridge (2). Preliminary results of mineral deposits from the first area were reported at UMI-2012 by James Hein et al. [2]. We present here the data of ferromanganese deposits from the Mendeleev Ridge.

Sep 1, 2014

A new test coke oven of 7 cu. ft. capacity is described. The oven was designed to simulate conditions in a central section of a battery oven and a special feature is the achievement of unidirectional heating from theflues on either side of the charge.The method of charging permits close control of charge conditions such as bulk density and moisture content.These conditions, as well as coking conditions (e.g. flue temperatures and coking time) must be varied to simulate conditions in different batteries. The effects of several variables on coke quality are discussed.Using test oven conditions corresponding to those of Newcastle steelworks batteries, good agreement was obtained between strength indices of test oven and battery cokes. For 17 tests, the average ASTM stability and hardness indices for the test oven coke were 38· 5 per cent and 69·7 per cent, while those for the battery coke were 37· 4 per cent and 67·6 per cent.Observed relationships between coke yield and productivity, and volatile matter and charge moisture are given.The use of a test oven to classify test coals into prime-, medium-, poor-, and non-coking coals is discussed.This may be achieved by observing the effects of the test coal in blends with other coals. The results of a series of blending tests are presented.The dangers of attempting to predict coke quality from a single coal property are pointed out, since this can be done only for very restricted ranges of coals.A diagram is given showing the established trends in the effects of blending various types of Australian coals on coke strength.

Jan 1, 1970

By Nikhil Dhawan, Veeranjaneyulu Rayapudi

This study investigates upgrading of low-grade banded hematite quartzite iron ore (Fe ~31%). Conventional beneficiation was found to be futile. The susceptibility of iron phases to microwave exposure and their selective absorption assists in the liberation of iron values. Microwave exposure of coarse particles at 540 W for 10 min yielded a concentrate with Fe 56.30% and recovery of 50.68%. Conventional carbothermic reduction at 500 °C, 60 min and 9% charcoal yielded a concentrate with Fe 57.6% and iron recovery of 68%. The presence of sufficiently bonded silica leads to an easy formation of a fayalite phase. The microwave reduction design yielded FeG of 57.6%, FeR of 47% and a yield of 24% at an optimal condition of 540 W, 8 min and 6% charcoal. It was found that a small fraction of microwave-irradiated ore-charcoal mixture melted rapidly, and pure ferrite balls were observed within 8 min. An optical micrograph of a ferrite ball reveals the retained austenite and martensite phase.

By Michael J. Atwood

Many buildings in Boston are founded on untreated wood piles, which can deteriorate and lose their structural capacity if groundwater levels are lowered below the tops of the piles, exposing the wood to air in the unsaturated soils that surround the piles. The problem of wood pile deterioration due to lowered groundwater levels in Boston first became evident in 1929 following discovery of rotten piles beneath walls of the Boston Public Library building. Repairs to reconstruct the library building?s wood pile foundations were made in 1930 using pit underpinning methods. Today, more than 80 years later, the subsurface conditions beneath several of Boston?s historic neighborhood areas continue to be plagued with low groundwater levels - regrettably resulting in ongoing deterioration to the wood piles that support some of Boston?s oldest and most beautiful buildings. Pit underpinning is still recognized as the preferred approach to repair wood piles and restore uniform foundation support beneath the impacted buildings. This paper provides a brief historical review of the land filling in Boston through the early 1900s that led to the use of wood piles as building foundations. Also discussed is the impact that groundwater level can have on the long term performance of wood pile foundations and the pit underpinning procedures used to reconstruct decayed wood pile foundations in 1930 beneath the Boston Public Library, and today beneath some of Boston?s oldest buildings. Also included are discussions on engineering controls and permitting requirements that help ensure safety and protection to the workers and buildings during underpinning, and some procedures being used to supplement and improve the loading capacity of the reconstructed foundations and facilitate construction of new useable below-grade space.

Jan 1, 2011

By Peter Chou

A total of 117 slope stabilization drilled piers were installed as part of a major hillside revitalization project. The 110-million dollar development, known as Stratford at Kenwood, included an 18-story upscale senior residential tower, a 3-story healthcare building, and 4-story condominium buildings, offering approximately 580,000 square feet of living space with panoramic views of Downtown Cincinnati, Ohio. In an effort to establish a flatter hillside plateau for the new 4-story condominium and to create a cut and fill balanced jobsite environment, an 800-foot long row of drilled piers and a 600-foot long multi-tiered shear key system was used to terrace existing 1.5H to 3H: 1V steep slopes and support the new fill. These slope stabilization features reduced the amount of spoils needed to be wasted off-site and mitigated the risk of slope instability. An ODOT/FHWA research indicated that spacing of stabilization piers and necessity of top-connecting elements are highly dependent on pier diameter, spacing, soil type, depth to potential failure surface, surcharge loads, and pier deflection. Due to pre-existing deep buried swales, various load combinations, and the complex mechanism of soil arching effects between adjacent piers, both analytical and numerical computer modeling was performed to estimate the loading on each pier. New generation multiplexed, 3-Dimensional, Micro-Electro-Mechanical-System based inclinometers were installed between selected piers to confirm the pier design, and monitor the fill placement, as well as long-term slope stability.

Jan 1, 2009