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By T Baumgartl, R I. Maczkowiack, O White, P D. Erskine

Queensland legislation, industry codes and policies relating to mine rehabilitation and closure create the expectation of successful progressive rehabilitation and that the post-mining environment is being returned to a condition suited to a pre-agreed, beneficial end use. Yet none of the rehabilitated mined land in the Bowen Basin has been certified as successful by authorities suggesting there is a gap between current rehabilitation and the full environmental outcomes that the legislation could deliver. We tested the veracity of this perspective and reflect on where responsibility for any discrepancy lies.We first reviewed current Queensland legislation and industry codes relating to stakeholder engagement, rehabilitation, closure planning and post-mining land use. We tested the accessibility of the documentation trail for several recent coal-mining projects in the Bowen Basin and examined the level of detail in approval documentation. We then assessed the rehabilitation performance reports of these mines in relation to the contents of their approval documents. Legislation, guidelines and codes repeatedly emphasise the need to plan for closure before mine operations begin and to progressively perform rehabilitation with an agreed end-use in mind. Early stakeholder involvement in these processes and transparency of actions and outcomes are also encouraged by government publications. Overall, in terms of transparency, we found that relevant documents are generally available to the persistent enquirer. However, the rehabilitation and closure undertakings given in both mine company and regulator documentation were commonly generic and rehabilitation obligations were not explicitly incorporated into rehabilitation plans. Rehabilitation reporting was also weak in that no distinction is required between successful and unsuccessful revegetation, nor to closure objectives and mine completion criteria. Responsibility for the apparent disconnect between regulatory intent and actual performance appears to begin with the regulator too readily allowing generic information and in not requiring performance reporting to correspond with approved post-mine conditions. As a result, companies may have a much greater rehabilitation and closure risk than mine management expects. More poignantly, the checks and balances that are in the legislation are not yielding the environmental outcomes of which they are capable.CITATION:White, O, Maczkowiack, R I, Erskine, P D and Baumgartl, T, 2012. Walk or talk - Is the current mine approval process in Queensland delivering rehabilitation and closure success?, in Proceedings Life-of-Mine 2012 , pp 59-68 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By George W. Small

The ore, as it is raised from the mine, has all average assay-value of $11 per ton, chiefly in the form of free gold. All the ore goes directly to the stamp-mills, of which there are two. The older and larger mill contains sixteen batteries of five stamps each, with one Frue vanner to each battery. The new mill has eight batteries of five stamps and two Frues to each battery. The large mill is driven by Leffel turbine wheels, with a pressure of eighty feet, and a consumption of 600 miners' inches of water. The smaller mill is driven by "hurdy-gurdy" wheels with a pressure of about 550 feet and a consumption of 150 inches of water. At both mills the tailings from the stamps pass over about 20 feet of plates on their way to the Frues. In each set of plates the first or upper one is copper, the rest are so-called silver plates. The bullion from the stamps is about 800 fine in gold and 200 in silver. The concentrates from the Frues average from 11/4 to 1 ; per cent. of the ore stamped. They very rarely exceed 2 per cent. I was unable to get the exact assay-value of the concentrates, but it is said to vary between $100 and $200 per ton. The concentrates are treated at the chlorination works at the rate of one hundred tons per month. The capacity of the works is somewhat greater than this, but as the supply of concentrates is limited it is not deemed advisable to work them up any faster. Care is taken to keep the concentrates always damp until they are put into the roasting furnace. If this is not done, a decomposition of the pyrites begins, forming lumps which do not roast, and which consequently cause a loss of gold in the residues from leaching. A Fortschaufelungsofen is used for roasting. Its dimensions, incloding fire-box, are 12' X 80'. The hearth is one continuous plane, but the charges, of which there are three in the furnace at one time, are kept entirely separate. The furnace-men call the three compartments, the "drying," the " burning," and the " cooking" compartments. In the middle, or "burning" compartment, the ore is spread

Jan 1, 1887

By Danny Winters, Wesley Schmutzler, Christopher Lewis, Matteo Bertoni

"SR 83/US 331 is a primary North/South roadway in Walton County that is a crucial link for tourism and commerce between the Walton County beaches and the heavily traveled I-10 corridor in the panhandle of Florida. The facility also serves as the primary hurricane evacuation route from southern Walton County. This 3.4 mile project involves expanding the current two-lane crossing of Choctawhatchee Bay to a fourlane facility to increase capacity and dramatically improve mobility within the corridor. One of the major goals of the project is to perform ground stabilization using Deep and Shallow Soil Mixing (DMM & SMM) along existing causeways. Ground stabilization is required due to the existence of moderately deep very loose soils that have settled considerably over the years. As a result, the Florida Department of Transportation (FDOT) incurred significant maintenance expenses and was unable to maintain an acceptable ride quality. FDOT considered soil mixing as one option to control this settlement. Quality Control for soil mixing relies heavily on the monitoring system used to control mixing parameters. This paper will examine in detail, the reporting of the Drilling Mate System (DMS) used to ensure the quality of each soil mixed element.INTRODUCTIONThe Florida Department of Transportation (FDOT) issued a Design-Build Maximum Price Request for Proposal (RFP) for the Choctawhatchee Bay Bridge expansion. The design-build (D/B) team of Skanska/Parsons Brinckerhoff was awarded the contract. The D/B team, in order to meet the unique deep ground improvement challenges of the Choctawhatchee Bay Bridge Project, selected Foundation & Geotechnical Engineering (FGE) as the engineer to design the ground improvement and TREVIICOS South (TIS) to execute the works.The FDOT in their RFP states that “either bridge or utilize a deep ground improvement method to stabilize the three segments of the existing earthen causeway” and “one possible method of deep ground improvement which is considered viable is deep soil mixing”. FGE developed a proposal to provide a unique rigid transfer platform to effectively stabilize the existing causeways. This platform (Fig. 1) consists of an upper 10 ft thick stabilized soil layer which transfers axial load to a series of deep columns. This robust system guarantees superior durability, ride quality and pavement condition and will exceed all required design and performance criteria including, “Less than 2 inches of settlement within a 1,000-foot section”."

Jan 1, 2017

By G. Sandoz, C. A. Siebert

OIL quenching of steel, in good commercial practice, is carried out using a great deal of agitation in the quenching bath. Many of the tests reported in the literature represent the results obtained on steels quenched into still oil. Scott1 describes three stages of cooling in liquid quenching baths, namely: "State `A'-Vapor Blanket Cooling-In this, the first stage, a thin stable vapor film surrounds the hot metal. Cooling is by conduction and radiation through the gaseous film and is therefore relatively slow. "Stage `B'-Vapor Transport Cooling- Termination of the `A' stage is marked by wetting of the metal surface. Vapor forms copiously in bubbles and is carried away by gravity and convection currents to condense in cooler surrounding liquid. This is the fastest stage of cooling. "Stage `C'-Liquid Cooling--The `B' stage ends as the surface temperature of the metal approaches the boiling point of the quenching liquid. Vapor no longer forms, so cooling is by conduction and convection and the temperature difference is greatly decreased. This mode of cooling is slower than that of the `B' stage." Mechanical agitation of the quenching medium will accelerate all three stages of cooling. The greatest effect, however, will be noted on stage `B' because the removal of the bubbles from the surface of the steel will not be entirely dependent upon gravity and natural convection currents. The method employed in this investigation for evaluating the oils was the end quench test. The various oils were substituted for water as the quenching liquid and hardness determinations were made at various distances from the quenched end. Most of the tests were run using a 3/8-in. orifice with a 2 ½ -in. stream height. However, to check the effect of other velocities two additional conditions were used, namely: (I) A 3/8-in. orifice and 1-in. stream height, and (2) a ½ -in. orifice and a 3 ½ -in. stream height. In all cases the samples were suspended so that the quenched end was ½ -in. above the orifice. The steel used was an NE 9450 having the following analysis: [ ] Some tests were run on an NE 8740, 3312, and a 4340 steel. The results obtained on these steels confirmed those obtained on the NE 9450 and have therefore been omitted' from this paper. The test bars were machined from 1 1/8 -in. stock to 1-in. diam by 4 in. long.

Jan 1, 1948

By William J. Gillich, Gerald L. Moss

PREVIOUS studies of the shock loading of randomly oriented polycrystalline aggregates have firmly established that, after rather short load duration, hydrostatic compression closely approximates the shocked state.' However, McQueen deduced from pressure measurements with good time resolution that, during shock loading, metals begin to undergo a stress relaxation at the yield stress. He suggested that the relaxation is due to plastic deformation accompanying the change from a one-dimensional compression to a three-dimensional, hydrostatic, compression.' Stress relaxation may occur faster as stress is increased above the yield stress, but the existence of unidirectionally compressed states for finite times suggests that the concept of a unidirectionally distorted lattice should furnish considerable insight into the mechanical behavior of materials subjected to shock loading. Here, a crystallographic analysis is presented for the hypothetical situation where atom motion may be considered as unidirectional which, as indicated above, is a useful extension of the macroscopic concept of shock loading to the microscopic domain. Only motion caused by the com-pressive forces is treated; i.e., lattice vibrations upon which this motion is superimposed, as discussed by Fitzgerald, are ignored.3 The purpose of the analysis to be presented is to develop a description for single crystals of the lattice rotations that occur for idealized uniaxial strain deformation. The usefulness of such an analysis in realistic deformation is to give a method of specification of those properties of an initially distorted lattice which would affect the subsequent deformation. Non-axial complications that arise experimentally, such as off-axis rarefaction waves, must be treated in proper context. Consider the material element shown in Fig. 1 and let the compression be uniform at all regions of the element. Then, any interior point of the element is displaced in proportion to its distance from the base of the element. Accordingly, if the top of a unit element is displaced by an amount, (-K), with respect to the base, a point P(X, Y) will be displaced by (-KY). Crystal planes are, therefore, rotated by the compression. Analysis of this rotation may be accomplished from the geometry shown in Fig. 1 where the line OP is the edge of the plane {hkl} and N is its normal. The orientation of the crystal plane with respect to the shock direction is specified by the angle, before deformation. After deformation the edge of plane {hkl}

Jan 1, 1969

By Darrell L. Beddard

The test program information provided for some immediate changes on the upcoming contracts and in contract administration for the I-880 Replacement Project. Plan sheet modifications included changes to the pile data tables showing the actual demand load required for structural stability. The normal class of pile with a minimum load carrying capacity was removed. This provided for substantial pile length reduction at several locations since the structural loading was much less than the predetermined pile class ultimate capacity. New specifications were developed and standard specifications were modified to accommodate the newer foundations, installation procedures and pile acceptance criteria. Current Caltrans specifications require that the Contractor provide bearing capacity at the specified tip elevation. This requirement was removed and pile acceptance was determined by the Engineer. Acceptance criteria was established by the State and was based on. set-up trend over time. Static loading tests were reduced especially in areas where testing was performed on the indicator program. Testing procedures were modified and set-up periods were established before piles could be tested. For the contract near the San Francisco Oakland Bay Bridge (Unit E) the FHWA 1000 tons (8.9 MN) test beam configuration was completely changed. This provided added safety and allowed more tolerance in the pile placement for the testing operations. Indicator piles were added as companion piles to the static loading test piles. These piles were used for restrike events which included collecting dynamic data for calibrating the wave equation analysis with static load test results. Indicator piles also provided quick access for restrike events, where as, the static loading test pile needed modification to perform the restrike operation. Penetration rates were recorded for these operations. Wave equation Analysis Program (WEAP) was used in developing the acceptance criteria. The standard Engineering News Record (ENR) formula in the current Caltrans' Standard Specifications was removed for the contracts. Contractors were required to submit, prior to driving piles, a driveability study for their contract. These studies required discussion of their operations, method of installation, effects of soil set-up, set periods, hammer settings, bearing graphs, inputs to the WEAP program and complete a "Pile and Driving Equipment Data" form. Dynamic monitoring was detailed in the specifications on how the monitoring process was to occur. Set periods were established and restrike events were called out with the frequency of these events.

Jan 1, 1996

By H. C. George

Since 1911, when J. L. Dunn first used compressed air for repressuring depleted oil sands in southeast Ohio, the rejuvenation of many depleted oil fields has been directly due to repressuring by means of air or gas. Developments in repressuring in recent years have resulted in its successful use in the early life of some deep, high-pressure oil fields, conserving the natural gas dissolved in and associated with the oil by returning it to the producing oil sand after it has been compressed above the existing rock pressure of the reservoir. One of the most successful operations of this type is that of the Humble Oil & Refining Co., on the DeWalt salt dome at Sugarland, Texas. I quote from a personal communication with reference to this field: "Structurally, the field is dome-shaped, having a closure of approximately 350 ft. Production comes from a sandy shale interbedded with a clean sand and lying over a cap rock which is about 3400 ft. deep on top of the structure." A feature of the operation of this field is the production of the required amount of oil with the minimum of gas production. Wells on top of the dome have high gas-oil ratios, while those down structure have lower ratios, depending upon the distance of the well from the peak. To date, it has been possible to produce the oil needed from the wells circling the dome above the water zone and below the gas zone, and in this manner the average gas-oil ratio has been kept low. The gas from all separators is turned into a gas system which serves the entire field. From this system, all drilling rigs and utilities requiring gas for a fuel draw their requirements, and the remainder of the gas (about two-thirds of the production) is delivered to a compressor plant which boosts the pressure until it can be returned to the sand at the top of the dome where the rock pressure is 1400 lb, per square inch. "The Sugarland wells produce through 2-in. tubing with a 3/8-in. choke in one wing of the well-head manifold. The pressure builds up as high as 1300 lb, per square inch on the casing while on the tubing it varies from 0 to 900 lb. per square inch, depending upon the amount of gas produced with the oil."

Jan 1, 1931

By George Smith

THE discussion of production control at the Insti-tute's annual meeting was profitable in that it started some thinking. One pertinent question there raised was how the opening of new mines, whose now unneeded output would inevitably react on prices, could be postponed until the market was ready to ab-sorb their output. In transportation some restraint is being exercised on building new and unneeded fa-cilities, but in production no general solution of the problem has been offered. Yet in a special field of new development of increasing importance a quick and easy solution has been suggested. I refer to the leasing of mineral deposits on the public domain. The report of the United States Coal Commission says: "In its possession of approximately 60,000,000 acres of public coal lands the Federal Government has its own responsibility in restraining overdevelopment. The Department of the Interior, which has control of these lands under the leasing law, construes the law as giving the department no discretionary right to refuse applications for leases regularly made by qualified citizens or corporations for coal deposits on the pub-lic domain. It presumes, that the applicant believes there is a need for an additional coal mine in his local-ity and expects to find a market for the coal produced. Overdevelopment, however, is a fact in the West as well as in the East, and wherever present involves needless investment and excessive costs of operation. Plainly, the leasing law should be so amended as to give the executive department full discretion in its approval of the opening of a new coal mine on the, public domain, making that approval contingent on the showing that the new mine would serve the in-terest of the consuming public." A similar view of the Federal Government's re-sponsibility in restraining overdevelopment of its oil lands has been presented by the Federal Oil Conser-vation Board. The leasing law vests little or no dis-cretion in the Secretary of the Interior, who must grant a lease to a qualified applicant regardless of any obvious country-wide condition of surplus produc-tion. This wide-open invitation to exploit and dissi-pate the people's own oil resources could be restricted by simple legislation, although as remarked by the board, such a legislative remedy for a plain economic ailment "does not evoke popular support when its purpose is avowedly to put the brakes on development of natural resources."

Jan 5, 1928

By Nathaniel Arbiter

In attempting to assess the contributions of Antoine Gaudin to the profession which he illuminated for almost a half-century, we will need to examine a very broad canvas. He was active in three significant areas: as a teacher; in research, both through his own endeavors and those of his students; and as a consultant to the mining industry and to the Government. Beyond these specific contributions, there was the major personal influence he had on scores of students, friends, and colleagues in the profession. If a single measure of the man's contribution is to be found, it will be the extent and direction in which he influenced the practice of his profession. To find this we should examine the state of miner- al processing when he began his activities in the 19201s, the progress which has taken place over the past half-century, and the part his activities played in this advance. However, there is a provocative and broader examination which I have chosen to make instead. This is to examine the past century in mineral processing through the lives of three men who, by common agreement, stand on the heights, both in teaching and in their contributions to industry: Robert H. Richards, Arthur F. Taggart, and the man whose memory we honor this evening, Antoine M. Gaudin. Their careers, by coincidence, cover just a century. This is also AIME's first century, and the first century of mineral industry education in the United States. In fact, mineral processing itself on any significant scale in the country encompasses only a century and a quarter. BEGINNINGS OF PRACTICE IN THE U.S. Before the 1840’s, U.S. mining, except for coal and iron ore, was on a small scale and was confined to the eastern states, with processing practically nonexistent. The 1840's saw the beginning of Michigan native copper production, including ore dressing; the 1850’s, iron ore production in Minnesota; and the 1860’s, lead production and processing in Missouri. But the most explosive event was the California gold rush after 1848, which not only brought tens-of-thousands of fortune hunters to the West, but also catalyzed broad mining activities and processing within the following decades. This was not only in California but, after the first fever of the gold rush subsided there,

Jan 1, 1976

By A. R. Elsea, E. E. Fletcher

This paper describes a metallographic investigation of the influence of tungsten or molybdenum additions upon the transformation and precipitation reactions occurring in Co-rich Co-Cr alloys. It is shown that tungsten has little effect upon the a-ß transformation temperature range, while molybdenum tends to raise it. Both elements tend to promote the formation of ? phase, molybdenum being more potent in this respect than tungsten. HIGH temperature alloys, that is, alloys which have load-carrying ability at elevated temperatures, have been developed at an increasing rate during the past few years. This has resulted from the requirements in the design of modern aircraft engines. Although many alloys of this type are available, they have been developed on an empirical basis. Metallurgists do not have a clear understanding of the phases or structures that are responsible for these high temperature properties. In order to determine why these alloys possess this particular ability, a project was started at Battelle Memorial Institute with the object of learning more about the fundamental factors which promote high temperature strength in alloys. This study was to include a correlation of microstructure and the high temperature properties of Vitallium, an alloy which is widely used for high temperature service. Vitallium is a complex material both from the standpoint of composition and microstructure. Consequently, it was necessary to obtain informa- tion regarding the phase relationships in this alloy. The Co-Cr binary diagram was determined as the first phase of this investigation.' A second paper described the effects of iron, nickel, or nitrogen on the reactions occurring in the Co-rich end of this system.' The present paper covers a continuation of this investigation in which the effects of tungsten or molybdenum on the reactions occurring in Co-rich, Co-Cr-base alloys were determined. Preparation of 'rest Materials Two series of ternary Co-Cr-base alloys, representing Co-Cr ratios of 80:20 and 68:32 ( Cr x 100 =20 and 32 ) , were prepared containing ( Co + Cr = up to 6 pct W and up to 12 pct Mo. Melting stock consisted of electrolytic Co, electrolytic Cr, 99.9 pct pure W, and 99.9 pct pure Mo. Table I lists the chemical analyses of these materials. The melting furnace was a vertical porcelain tube

Jan 1, 1952

By Sanai Nakabe

Japanese wartime economy demanded domestic cobalt production. This paper describes a process operated for two years at the Besshi mine and smelter on extremely low grade (0.1 pct Co) pyrite concentrates obtained from copper ore. 'The steps in the process were roasting, leaching, precipitation, reduction fusion to crude cobalt, and finally refining by electrolysis to 99+ pct. COBALT ore deposits in Japan are all small and of poor grade. In the past, a small amount of cobalt has been produced from the best portions of a few of these deposits, and very little production is expected in the future. In addition to these lean cobalt ores, cobalt is present in the cupriferous pyrite which is fairly abundant although of low grade, as is shown in Table I. Considerable cobalt is expected from these deposits because of their extent. Cobalt cannot be exclusively recovered economically from ore of this type; however, if means could be devised to recover it as a byproduct of copper production, a fairly large production at reasonable cost could be expected from Japanese sources. It was along this line that the research work was done. Selection of Suitable Process The process for extracting cobalt differs from ore to ore according to their composition. The difficulty in cobalt metallurgy arises from the fact that chemically cobalt resembles many such common metals as Mn, Fe, Ni, Cu, and Zn, associated with it in the ores. In the present case the most serious difficulties were: 1—Extremely low grade ore, 0.1 pct Co. 2—The large proportion of iron accompanying cobalt and its close similarity in chemical behavior. 3—The fairly large proportion of zinc and manganese and their chemical similarity to cobalt. The recovery of cobalt oxide as a byproduct of the hydrometallurgy of copper had been attempted in Japan but was stopped after a short period because it proved uneconomical. The literature disclosed no method for the recovery of cobalt from cobaltiferous copper pyrite and it was therefore necessary to devise a new process. The following basic principles were considered in selecting the process: 1—A major alteration in copper production methods should not be necessary. 2—The first step should be the extraction of cobalt leaving the large quantity of iron unaffected. For this purpose wet metallurgy would be preferred.

Jan 1, 1952

By John D. Meahin

THE use of digital methods for generating crystallo-graphic data is well-established and many programs are now available. Transmission electron microscopy usually requires a knowledge of the electron diffraction pattern which is obtained by plotting a planar section through reciprocal space. With cubic symmetry these sections are very easily produced, but with hexagonal and lower symmetry systems considerably more labor is involved. Johari and Buchanan1 have written a Fortran program for generating standard projections and along similar lines we have produced a short but completely general program for generating any section through reciprocal space. The required inputs are the lattice parameters and angles for the real crystal. The Miller indices of the direction [U, V, W] parallel to the electron beam are then specified and the program will generate the Miller indices of the plane normals perpendicular to [U, V,, W] up to some specified integer. A subroutine can be inserted to test for forbidden reflections if desired. We have used such routines for fct and hcp crystals. As each permitted index is generated it is printed or punched out and no storage arrays are utilized in the computer. The normal diffraction pattern corresponds to the zero-order Laue zone, but with thin crystals or crystals of large lattice parameters the higher-order Laue zones may contribute to the diffraction pattern. Accordingly the program will generate successive Laue zones and project them onto the zero-order zone. The output of the program first lists the zone axis [C, V, W] and the Laue zone, and then gives a list of permitted reflections and the corresponding XP and YP coordinates of the reciprocal lattice point in angstroms-'. In addition, ZP, the perpendicular distance of the reciprocal lattice point from the (U, V, Ur) plane in reciprocal space is given, as is the reciprocal interplanar spacing. In the case of the zero-order Laue zone ZP is zero. A diffraction spot from the higher-order Laue zones will be very slightly displaced from the computed coordinates as its position in an actual pattern is given by projection along the diffracted beam2 and not along [u, V, w]. For any given electron wavelength this correction could be readily incorporated into the program, but as it only amounts to -1 pct it was decided to leave the program in its most general form, i.e ., a computation of points

Jan 1, 1970

By Ralph H. Sweetser

AT the joint session of Blast Furnace and Open Hearth Committees, April 7, 1937, at Birmingham, the subject of the quality of basic open-hearth pig iron was so well presented and discussed from so many different viewpoints that it was the general opinion that progress had been made and that such meetings were conducive to the advancement of the art of making pig iron of the right quality for the open-hearth man to produce the most satisfactory quality of steel. It was agreed that there is a decided differentiation between the chemical analysis of pig iron and the "quality" of pig iron. Paul J. McKim said that open-hearth furnace operators frequently make reference to certain types of iron as "bad iron," "dirty iron," "cold metal," etc., claiming that when using these irons, although they are within specified chemical analysis, it is impossible to produce quality steel. Mr. McKim gave a list of the suggested causes of those "certain types" of bad irons that have a thoroughly respectable analysis but a thoroughly disreputable character. Another open-hearth man, P. A. MacIsaac, of Nova Scotia, said that The effects of iron that is below standard in analysis or in that mysterious property called quality, are well known to all open-hearth operators. It has been shown that iron of this type results in the production of steels on which the rejections of finished product run high. What is to be done about it? I would say that the burden of producing high-quality iron should be placed squarely on the shoulders of the blast furnace man, even as that of making good steel is shouldered by the open-hearth man. It is the purpose of this paper to bring out into the open this "mysterious property called quality"; that is, in those "certain types" of basic pig iron that make it impossible to produce quality steels; and at the same time to point the way for the blast-furnace man to be able to shoulder the burden that Mr. MacIsaac and all other open-hearth men and foundry-men have placed upon him. Silicon, sulphur, phosphorus and manganese are not the guilty elements because these are known, specified and usually kept within the

Jan 1, 1938

By R. Dawson Hall

The stresses in the simplest structures are often those we find most difficult to analyze. The most complex condition in mine stresses is found in simple tunnels where the roof, the sides, and the floor are a monolith. The functions of the parts are like the parts themselves not distinct and spccialized, and the problems to be solved are like those in a metal structure with riveted joints or a redundancy of bars. This difficulty explains perhaps why the condition has not been treated. But just because it cannot be discussed in its entirety is no reason why it should be treated as an action of parts with spccialized functions as a roof beam with supports and a foundation. The problern cannot be ignored on the ground that it is not of sufficient importance to warrant careful consideration, because conditions of complete monolithism, of which the tunnel is the type, are found materially unchanged in room-and-pillar and in longwall work. This unity between roof, sides, and floor, which to the coal miner is a difficult conception, really deserves a scientific appellation, and perhaps holoid (from holos, whole, and eidos, form) will serve the purpose as well as any other. In a simple tunnel the roof, the sides, and the floor form integral parts of one and the same structure, and the distortion of one cannot be conceived without a consequent strain in the others. Thus when the roof of the tunnel droops by reason of its weight, the upper parts of the sides are drawn in becausc they are integrally connected with the roof and must approach each other whenever, by the sagging of the roof, the distance between any two points in it is diminished. (See Fig. 1.) Thc sides in their turn operate on the floor of the holoid structure, producing a tensile stress. The writer has always been impressed with the value of soap as a means of illustrating the action of mine stresses. With that idea in mind' a cake of naphtha soap measuring 43/8 by 2¼ by 19i in. was taken and a tunnel was made through it 13/4 in. long, 21/2 in. wide and 1¼ in. high. (See Fig. 2.) A load was then placed at the mid-span of the tunnel. Eventually, the upper bar, or "roof," broke at the

Jan 1, 1916

By William P. Mason

FoR reasons unnecessary to enter into here, I was called upon to contradict the statement that " closed metallic vessels, partly filled with water and heated, do not become shattered by violent explosion, but simply rupture by over-pressure;" and the following experimental results were obtained in support of my position : A piece of drawn brass tubing (telescope-tubing) 1 1/2 inches in diameter and 15 inches long was closed at both ends by screwing on heavy caps of bronze. Before closing the second end the vessel was half filled with river water, the cap was then screwed on, and the closed vessel was supported upon two iron anvils, and heated in the interval between the supports by a large Bunsen lamp. The resulting explosion (which was doe to over-pressure only and not to any more occult cause) was exceedingly violent. No small damage was done to the room in which the experiment was undertaken; and the noise was like that of a cannon. Those of the pieces which could be recovered are shown in Fig. 1. Upon examining the wreck, it was noticed that one of the heavy bronze end-caps had preserved its circular section and still contained that portion of the barrel of the tube which had been screwed into it, while the other end-cap contained no portion of the tube, and was moreover sprung into a shape more or less elliptical, as if from excessive lateral strain. It was also observed that the large pieces of the shattered boiler predominated towards the end which had been closed by the un-sprung end-cap. The reasonable explanation, in view of the facts, was, that over-pressure had caused the boiler to yield through the screw-threads at A B, Fig. 2, and the righthand end-cap had blown off, thus leaving the boiler half filled with water, greatly super-heated for the new (atmospheric) pressure to which it was suddenly reduced; that this water had consequently sprung instantly into steam with dynamite effect, shattering the tube and springing the remaining end-cap. The large pieces would be expected at the open end of the boiler, as at that point the "tamping "would have been that of the atmosphere only. This explanation assumes a rupture to have been caused by gradually increased pres-

Jan 1, 1893

By Stanislaw Wasilewski, Zdzislaw Krzystanek

The CMC-3 new generation system for continuous methane monitoring enables on-line measurement of methane concentration within the range of 0-100% CH4 with a great autonomy of operation. In principle the system has been worked out in the asspect of hazard detection in mines endangered with rock and gas outbursts. But after last crash in the Halemba colliery, according to the recommendation of the after-accident committee, the system was directed to this colliery for operational tests. The paper describes construction and functions of this system and gives some results of tests conducted at the Halemba colliery. The results point out the necessity of using monitoring equipment of continuous operation in mines of high dynamics of methane emission. INTRODUCTION Commonly used in Polish coal mining the methane monitoring systems of CTT/63/46 Up or CMM-20 and CMC-1 type are based on cyclic measurements with 4-minute repetition of measurements. This period has been stated sufficient from viewpoint of methane emission dynamics under normal exploatation. In these systems, automatic switching-off electrical power is performed by the surface station, i.e in case of detecting exceeded concentration value the station generates control pulse signal which actuates the switchng-off devices CRA and IZZO. Such a way of disconnection causes a considerable time delay, up to several minutes, in electric power break at hazardous areas. In the methane monitoring system with the new CMC-3 station, the different phylosophy of operation has been applied. Measurement of methane concentration is performed in a continnous way. In case of exceeding the alarm value, immediate control of the IZZO unit directly by methane monitor follows and consequently energy break without necessity of communicating with the surface station. Alarm values are set directly in methane monitor. The system ensures central powering of underground equipment from the surface, and in case of power failure the methane monitor equipped with battery operates autonomously for about 12 hours. Such an extention of the methane monitor funtionality has been achieved thanks to the use of internal microprocessor controller. The system with the CMC-3 station has been worked out in the aspect of methane hazard detection in mines exposed to gas outbursts. But after last gas explosion, according the desicion of the After-accident Commitee, the system was installed in the Halemba coliery where it underwent operational tests. Besides

Jan 1, 1993

By David Hurth

JOHN HAMRIC: Our next topic leader is David Huth, superintendent of sulfuric power generation, DAP, and shipping for IMC-Agrico, Nichols Plant, Mulberry, Florida. With a title like that it's no wonder he believes in empowerment. His topic today is "The Triumphs and Pitfalls of Using Empowerment Techniques." DAVID HUTH: Empowerment and its benefits are a desirable alternative to the traditional management structure. The difference between the two is the amount of decision- making authority and responsibility given to individuals by a supervisor. Just what is empowerment and how does it work? Empowerment is relinquishing to individuals the authority and responsibility to make daily decisions. Can everyone be empowered? What if they make a wrong decision? Will I empower myself out of a job? These are questions that all managers have when they hear the word empowerment. In today's fast-paced and high-pressure business environment, the old way of managing people must be replaced with a new approach. No longer can we, as managers, make all the decisions. The increased work loads due to downsizing, consolidation, and synergies have stretched us too thin. What about our employees? How can we motivate them into the high-performance teams that our companies are demanding? What possibly could satisfy both these issues? The solution to these problems can be solved with the power of employee empowerment. Employee empowerment will not only lessen the load on managers but will build teamwork, motivation, and pride into the employees who work for the managers who use it. American business was rudely awakened in the early 1980s when the Japanese companies not only caught up to American companies but literally flew by them. America was fat, dumb, and happy after World War II. Why wouldn't they be? They had all the factories. Everyone else had to rebuild. So for 40 years American business lounged in the limelight of very little true competition. But times change. Unfortunately, American business did not. Now the cry to perform in the new global economy has come down from the corporate boardrooms. Down through the ranks it has been felt. Guess who is supposed to make it work? But where are all those people who are going to make this rejuvenation and corporate renaissance possible? Many of them are gone-lost in downsizing, synergies, and rightsizings

Jan 1, 1998

By S. Rupprecht, G. Rapson

Long blast hole drilling has been successfully implemented since the 1950s in caving operations, steeply dipping wide reefs and boxhole/raise developments worldwide. However, when applying long hole drilling to narrow tabular reefs, the challenges of achieving high economic drilling rates, combined with acceptable accuracy and appropriate powder factors have yet to be overcome. The focus in this paper is the selection, application and optimization of long hole drilling equipment at mining operations shallower than 2 000 meters. The drilling, blasting and cleaning operations have to be optimized as a process if maximum production at minimum per unit cost is to be achieved. For this to be possible, it is essential that the mine design and layout match the mining process being implemented. The critical parameters affecting the sustainable implementation of long hole drilling in stoping applications for platinum mines are improved safety and higher production rates compared to conventional methods. In terms of drilling, both top hammer and down-the hole hammer configurations have been considered. For economic drilling, the benefits of monitoring and optimizing performance (i.e. drill bit rotation, thrust, and percussive power) for specific rock types are discussed. While the drive is for longer, more accurate, smaller diameter holes to reduce drilling costs, the design of appropriate blast hole patterns and the corresponding charging and initiation systems is crucial for success. The effect of hole diameter and pattern on the powder factor, when comparing small diameter, shorter holes versus large diameter, longer holes, is a major factor in achieving good blasting results. Once appropriate drilling and blasting have been implemented, the cleaning process becomes a potentially critical operation to ensure the production, cost and safety goals are met. Hence, the blast hole pattern and charge have to be integrated for optimal fragmentation to suit the cleaning cycle for maximum production output. Providing that long blast hole drilling is applied as a process in a planned, committed and well-managed manner, the benefits in safety, production and cost over conventional methods should be achievable. However, if the implementation process is not planned and supported by all parties concerned, it will not be possible to succeed in the new operation. Hence, an implementation or roll-out plan of new technology is crucial for success.

Jan 1, 2004

By M. B. Ramachandra Rao

The spontaneous polarization surveys dealt with in this paper were carried out near Guddadarangavvanahalli (lat. 14° 17' N.; long. 76° 24' E.) in Chitaldrug district, which forms part of the Chitaldrug schist belt. The occurrence of gold, copper, lead and antimony ores has been noticed for several years but efforts to exploit them have been unsuccessful, therefore some spontaneous polarization surveys were made in the hope of finding indications of workable ore bodies. The country examined has a rugged topography, with numerous hills on which there is little vegetation. The climate is generally dry, the average annual rainfall of the tract being about 25 in., of which 17 in. occurs during the southwest monsoon. The geological formations of the area pertain to an ancient schistose series known as the Dharwar system (Archean). Locally, the rock formations have been divided into three series1—the chloritic series (or the Chitaldrug formation), the clay series (or the G.R. formation) and the trap series (or the Jogimardi trap). The chloritic series includes a complex of altered ancient traps and volcanic agglomerates intermixed with some schists of sedimentary origin, all of which are highly metamorphosed. The lithological types of this series are mostly distinguishable as greenstone schists, calc-chloritic schists, slaty schists, ochery and calcareous mica-chlorite schists, with subordinate bands of secondary limestone. The clay series (G.R. formation) is made up of shaly and argillistic schists, litho-margic clays, sandstones and brecciated ferruginous quartzites. The Jogimardi trap is mostly of the nature of an epidiorite (hornblende diabase), which is distinctly intrusive in the form of large laccolithic and narrower dikelike masses. In addition to this trap, there are other minor intrusives such as the chalybitic trap, quartz porphyry and quartz reefs. The topographical and geological features of the area are noted on the map of Fig. I. The locations of some of the spontaneous polarization centers determined by the geophysical survey are indicated also. Method of Survey and Apparatus Employed The spontaneous polarization surveys were carried out in the manner recommended by the Imperial Geophysical Experimental Survey.2 Preliminary reconnaissance was first carried out along a series of parallel traverse lines that were laid out over the area. The Potential profiles obtained in these traverses were plotted* on a suitable scale and when any

Jan 1, 1946

By M. B. Ramachandra Rao

The spontaneous polarization surveys dealt with in this paper were carried out near Guddadarangavvanahalli (lat. 14° 17' N.; long. 76° 24' E.) in Chitaldrug district, which forms part of the Chitaldrug schist belt. The occurrence of gold, copper, lead and antimony ores has been noticed for several years but efforts to exploit them have been unsuccessful, therefore some spontaneous polarization surveys were made in the hope of finding indications of workable ore bodies. The country examined has a rugged topography, with numerous hills on which there is little vegetation. The climate is generally dry, the average annual rainfall of the tract being about 25 in., of which 17 in. occurs during the southwest monsoon. The geological formations of the area pertain to an ancient schistose series known as the Dharwar system (Archean). Locally, the rock formations have been divided into three series1—the chloritic series (or the Chitaldrug formation), the clay series (or the G.R. formation) and the trap series (or the Jogimardi trap). The chloritic series includes a complex of altered ancient traps and volcanic agglomerates intermixed with some schists of sedimentary origin, all of which are highly metamorphosed. The lithological types of this series are mostly distinguishable as greenstone schists, calc-chloritic schists, slaty schists, ochery and calcareous mica-chlorite schists, with subordinate bands of secondary limestone. The clay series (G.R. formation) is made up of shaly and argillistic schists, litho-margic clays, sandstones and brecciated ferruginous quartzites. The Jogimardi trap is mostly of the nature of an epidiorite (hornblende diabase), which is distinctly intrusive in the form of large laccolithic and narrower dikelike masses. In addition to this trap, there are other minor intrusives such as the chalybitic trap, quartz porphyry and quartz reefs. The topographical and geological features of the area are noted on the map of Fig. I. The locations of some of the spontaneous polarization centers determined by the geophysical survey are indicated also. Method of Survey and Apparatus Employed The spontaneous polarization surveys were carried out in the manner recommended by the Imperial Geophysical Experimental Survey.2 Preliminary reconnaissance was first carried out along a series of parallel traverse lines that were laid out over the area. The Potential profiles obtained in these traverses were plotted* on a suitable scale and when any

Jan 1, 1946