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By William B. Conway

This paper will describe the large caisson pier foundations for four of the bridges crossing the Mississippi River in the New Orleans area; and will discuss some of the unusual problems encountered during their sinking. Certain settlement phenomena experienced during their service life will also be related: The four bridges in order of their construction: The Huey P. Long Bridge, River Mile 106.1, completed in 1935 The Greater New Orleans Bridge No. 1, River Mile 96.0, completed in 1958 The Hale Boggs Bridge, River Mile 121.6, completed in 1983 The Greater New Orleans Bridge No. 2, River Mile 96.1, completed in 1988 Each of these bridges employed large open-dredged concrete caissons as foundations for one or more of the river piers, with the smallest being the 65ft by 102ft caissons for Piers I and II of the Huey P. Long Bridge and the largest being the 99ft by 214ft caisson for Pier II of the Greater New Orleans Bridge No. 2. The Huey P. Long caissons are founded in a dense fine sand at -170 while all of the other bridge caissons are founded in hard preconsolidated clay at elevations varying from -150 to -185. The Huey P. Long Bridge is currently being widened without increasing the caisson foundations under any of the river piers; and the design reasoning that led to this decision is presented.

Jan 1, 2013

By D E. Tennant

In the fields of geotechnical engineering and slope management, various software packages are used to assess the behaviour or propensity for a slope to fail. Traditional kinematic analysis calculates the probability of failure of design sectors with respect to dominant structural set orientations. A novel methodology is provided here to view potential hazardous slope behaviour in 3D, allowing engineers to make informed decisions regarding various pit slope geometries. Apparent dips are calculated for every point in space with respect to every slope orientation of the entire pit surface/design, specifically in reference to bench and inter-ramp planar failure mechanisms. Implementing a proactive approach to slope design will not only lead to early mitigation of risk but can also add direct value by enhancing or improving upon slope angles for earlier access to ore. From a safety perspective, identification of unfavourably oriented slope geometries can be dealt with before failure occurs. This methodology relies on a strong understanding of the existing rock mass anisotropy, particularly behind the face, thereby removing some of the uncertainty surrounding pit design as well as presenting engineers with an additional means to manage risk.

Nov 29, 2022

By M. Li, J. D. Miller

Existing process technologies for the production of soda ash from trona involves dissolution in hot brine, sedimentation and filtration for the removal of impurities, and subsequent crystallization for the recovery of soda ash. In this regard, mining and operating costs, particularly energy costs, are higher than desired. A preferred processing strategy might be to remove gangue mineral contaminants from the plant feed prior to dissolution in hot brine. Such a preprocessing strategy at ambient temperature and pressure has been limited by the lack of satisfactory process technology. Now based on recent results from laboratory research at the University of Utah it seems that the run-of-mine trona ore can be treated at ambient temperature and pressure using a special flotation procedure to separate the gangue minerals and make a trona concentrate with a purity of almost 99% trona at a recovery of more than 97%. The concept of such a new processing strategy is discussed with respect to current plant practice.

Jan 1, 2002

By Mason K. Banks

A process has been developed which produces spodumene concentrates assaying 6.0 pct Li2O and 0.45 pct Fe2O3, with 70 to 75 pct recovery of spodumene. Two flotation separations are required: the simultaneous removal of mica, feldspar, and quartz as a froth product using a cationic collector, and the subsequent removal of iron-bearing minerals as a froth product while spodumene is depressed as a tailing. SINCE the close of World War II there have been numerous developments resulting in the increased use of lithium by industry. Notable among these has been the development of an industrial lubricant, based on lithium stearate, which is fluid at low temperatures, stable at high temperature, and insoluble in water. A new bleaching agent, lithium hypo-chlorite, has also been developed recently.' Other well-known uses are listed below: 1—Lithium oxide in ceramics reduces firing time, lowers melting temperatures, lowers thermal expansion, raises refractive index, and improves chemical resistivity. 2—Lithium carbonate and lithium strontium nitrate are used in pyrotechnics for their brilliant red color.' 3—Lithium chlorides and fluorides are used as fluxes for welding aluminum and magnesium.' 4—The affinity of lithium for nitrogen is the basis for a process used in purifying helium." 5— Lithium chlorides and bromides are used in air conditioning for their powers to absorb organic amines, ammonia, and smoke.6-—Lithium hydride has been used as a source of hydrogen to inflate life rafts and balloons used by the Air Forces and Navy.' 7— Lithium metal and lithium hydride are useful in the atomic energy program in connection with the production of the isotopes of hydrogen." During the 1942-45 period of World War 11, Solvay Process Co. operated a flotation plant with a daily capacity of 300 tons of ore for the production of spodumene concentrate near Kings Mountain, North Carolina. The operation was shut down upon reduction of wartime demand for lithium chemicals, and until recently there has been no production from the Carolinas. In April 1950 an investigation of the problem of spodumene flotation from North Carolina ores was begun at North Carolina State College Minerals Research Laboratory at Asheville, N. C. This laboratory, operating under the combined auspices of North Carolina State College, North Carolina Department of Conservation and Development, and the Tennessee Valley Authority, undertook the spodumene project at the request of Foote Mineral Co. of Philadelphia. The work, involving a period of 15 months of intensive batch and pilot plant investigation, was completed in June 1951 and resulted in development of a process for concentration of spodumene by flotation which has been hereto unrecorded in the literature. A similar approach has been used before on iron, ilmenite, and other minerals, but the literature shows no record of its having been applied to spodumene. Parts of the process are now being used on a commercial scale at the Foote Mineral Co. plant near Kings Mountain, N. C., which has been in production since July 1951. It is the purpose of this paper to describe some of the results of the investigation. The Orebodies Spodumene-bearing pegmatites occur in a narrow belt 24.5 miles long and 1.8 miles wide extending southwestward from Lincolnton to Grover, N. C. According to statements judged to be conservative, the tin-spodumene belt of the Carolinas contains an estimated 4,300,000 tons of pegmatite ore averaging 15 pct spodumene. This amounts to "a reserve of at least 650,000 tons of spodumene (more than 20,000 tons of metallic lithium) to a depth of 100 ft."' This figure includes only bodies having an average thickness of 35 ft and length of 550 ft. There are hundreds of pegmatites in the belt, many of which are less than 10 ft wide. The largest pegmatite in the area has a maximum thickness of 395 ft and maximum length of 3250 ft.' These larger pegmatites are composed principally

Jan 1, 1954

By S. Fukushima, E. Kimura

In the Mitsubishi beneficiation process of ilmenite, chlorine is regenerated in the dechlorination furnace where the gases produced from a selective chlorination of ilmenite are directly introduced. The present paper describes a reaction mechanism and mixing characteristics of the reactant gases for dechlorination of ferric chloride with oxygen. A furnace of a small diameter where the reactant gases passed through in the state of nearly plug flow was used for determination of the effects of temperature and of partial pressures of ferric chloride and oxygen on the rate of the reaction. The experimental data of the reaction rate were applied to various models for calculations of the rate equations and the most suitable reaction model was determined. The results of the experiments also showed that effects of gas mixing onto the reaction rate could not be ignored, so that experiments of gas mixing was carried out. Gas flow patterns and scale effects were observed with use of transparent model furnaces of different sizes.

Jan 1, 1976

By D. J. MacDonald

The Bureau of Mines has carried out investigations on a method for producing zirconyl sulfate solution from zircon sand, comprising (1) reacting zircon sand with molten NaOH, (2) leaching the resultant fusion frit with water to remove sodium silicate and to convert sodium zircon-ate to hydrous zirconium oxide, and (3) leaching the hydrous zirconium oxide from unreacted sand with hot, dilute H2S04 to produce crude zirconyl sulfate solution. The following conditions were found to be suitable: reacting 0.6 kg of NaOH per kilogram of zircon sand for 10 min at 600° C; leaching the frit with 3 to 4 liters of water per kilogram of solids; leaching the residue with 5.1 liters of water and 1.25 liters of 98-pct H2S04 per kilogram of original solids for 10 min at 90° C; and filtering or decanting to recover unreacted zircon sand. A preliminary cost estimate is included.

Jan 1, 1982

By A. LA. Salama, D. B. Hyma

"The Western Research Centre (WRC) of CANMET located in Devon, Alberta, is a modern research facility offering services ranging from fundamental research to pilot plant investigations. Recently, a 0. 76 metre diameter by 7.9 metre high Flotaire column flotation cell was installed as a demonstration unit for Canadian coal producers. Because the column cell is intended to be used for research, development and demonstration, WRC recognized that additional sensing equipment and improved process control would be required to generate good data for subsequent column scale-up and engineering design.A low cost, personal computer based control system was, therefore, designed and installed. This paper describes the stepwise procedure in developing the control strategies, selection of system software and hardware, and installation and configuration of the system.Preliminary performance data on a western Canadian coal sample are also presented. Future testwork is planned on additional coal samples to expand upon existing database."

Jan 1, 1993

By Calvin J. Konya

Precision Blasting has designed easy to use, yet, highly powerful databases for storage and retrieval of blasting data. Three different Databases are available for blasting data management. The Vibration Data Management is a complete vibration record keeping system. The Blasting Data Management will record the information from the blasting report as well as the vibration data. The Explosives Inventory Control makes the control of explosives and initiators quick and easy.

Jan 1, 1991

By E. R. Maize

This report is the third of a series on convergence of roof and floor in coal mines and subsidence of surface that accompanies it. The first paper5/ dealt with extraction in a mechanized mine (Montour 10) having relatively short rib lines that retreat rapidly. The second dealt with extraction in a mine (Crucible) in which coal was loaded. by hand and in which the rib lines wore long and slow-moving. The present report deals with a mine (Gibson) in which conditions approximated those in the Crucible mine, except that the distance between room centers was considerably less and the pillars were narrower in consequence. Moreover, the average cover was less and the studies were made under the steep hillside of a stream valley compared with a gently rolling surface over the portions of the second mine studied. Gibson mine lies in the east-central hart of Washington County, Pa. , approximately midway between the Montour 10 end Crucible mines on a north-south line. A cooperative agreement covering the work was made with the Hillman Coal & Coke Co. through W. L. Affelder, vice president. This paper describes the methods used in the investigation, gives excerpts from the data obtained, and offers such generalizations as appear to be justified.

Jan 1, 1940

An assessment has been made of six reported methods for the determination of the swelling of iron ore pellets on reduction. The methods are discussed on the basis of apparatus requirements, reduction conditions, sample requirements, measurement of swelling and reproducibility. It is concluded that the CNRM, LKAB, and Lurgi methods are the most satisfactory which presently exist for determination of the swelling of industrially produced, iron ore pellets.

Jan 1, 1974

By Jonathan Peck, Jim Gray

"With the implementation of more advanced monitoring, control and locating systems in surface mines, there is an ever increasing need for their mine-wide integration toward achieving over-all optimization. AQUILA Mining Systems Ltd. is developing the basis for a comprehensive real-time monitoring, control and information system called the Total Mining System or TMS. This system is being designed to address both current and future needs of open pit mines toward improving productivity and minimizing costs, through better two-way information flow between each component in the operation. At a basic level, feedback from equipment and process monitoring will enable decision making to be based on quantitative, on-demand information, thus permitting proactive rather than reactive planning. Dynamic planning would be a valuable tool as market conditions fluctuate, equipment fleets age and variations in the grade, quality, geometry and hardness of the mined material all contribute to either changing production targets or levels of achievable performance. Such a capability could be implemented within the next two years.At a higher level, and within five years, autonomous operation and/or real-time supervisory control of mobile and stationary equipment in open pit mines will be achieved. A discussion is provided in regard to the development and implementation of an autonomous haultruck and blasthole drill, to demonstrate the need for such a system.This paper outlines a preliminary program for the design, development and implementation of this system, primarily in relation to high-level communications and its role in the future automation of open pit mobile equipment."

Jan 1, 1995

By B. Zondek, W. T. Cardwell, J. W. Sheldon

The fundamental equations that are used to describe two-phase fluid flow in porous media are Darcy's law for each phase and an equation of continuity for each component. The special case of one-dimensional, incompressible, two-phase flow has received much attention in the petroleum engineering literature.1-10 The basic paper on the subject is that of Buckley and Leverett.2 Buckley and Leverett showed that one could eliminate the pressure and obtain a single partial differential equation for the saturation. They solved this equation for the case when gravity and capillary forces are negligible. A frequently encountered property of the solution of the basic partial differential equation is that, as time progresses, the saturation becomes a multiple-valued function of the distance coordinate, x. Buckley and Leverett interpreted the formation of multiple values as an indication that the saturation-distance curve had be-come discontinuous. They developed a method of determining the position of the discontinuity from a material balance. We solve the Buckley-Leverett partial differential equation using the method of characteristics and the concept of shocks. Our treatment is analogous to treatments used in the theory of supersonic compressible flow." Although the numerical results obtained are the same as those obtained by previous methods, we believe that this approach is more logical and has broader applicability. It can, for example, be generalized to treat the case when the fluids are compressible. It is not clear how one would go about doing this using the method of Buckley and Leverett. To illustrate the power of the method of characteristics with shocks, we solve a problem in gravity segregation which has not been treated previously in the literature. A special case of the general method developed here was used by Welge, to solve a particular fluid displacement problem. We consider two-phase incompressible flow along the vertical direction x in a porous medium. We assume that there is no flow transverse to .x. We measure positive in the upward direction. The fundamental equations are obtained from Darcy's law and the mass conservation law. Since the two phases are incompressible, mass conservation is equivalent to volume conservation.

Presentation Plan Hoist ropes ?Importance ?Mandatory and routine Inspections Continuous monitoring of wire ropes for mine hoisting ?Why a continuous monitoring of mine hoisting ropes.? ?Description of the ??Contiscan?? monitoring system ?Information data gathering Advantages of the ??Contiscan?? monitoring system ?Visual rope inspection on daily basis ?Monthly inspection ?Payload capacity flexibility and potential increase for deep mining operations. ?Periodical inspections by external experts ?Importance of the costs associated with hoisting production shutdowns. Commercialization and availability

Aug 1, 2013

By Taylor G. H

The proposed classification scheme is based on two primary parameters, one for petrographic composition and the other for rank, both being determined with microscopical techniques. The scheme has been applied to a wide range of Australian coals and found to provide a useful means of relat- ing their inherent properties to properties such as volatile- matter yield, crucible swelling number, and calorific value, which will determine how these coals might be used coimierciallyti,

Jan 1, 1969

By Madan M. Singh

Mining under bodies of water such as oceans, lakes, rivers, streams, ponds, and other impoundments, is not a new technique. However, in the United States it has been fairly restricted to date. In order to recover the maximum amount of the nation's reserves, in the future, it is important that further mining under such bodies of water be planned. However, it is imperative that this is not done at the expense of danger to the nation's miners or appreciable property damage. If all the bodies of water are considered large, and it is assumed that these constitute a hazard when mining in their vicinity irrespective of their size and geometry, a significant percentage of the coal reserves are likely to be sterilized. How- ever, by adopting special mining plans and procedures, it may be possible to release reserves for exploitation that would otherwise be unmineable since the surface of bodies of water below which they lie are relatively small in size. In 1977, the Bureau of Mines issued Information Circular (IC) 8741, entitled "Results of Research to Develop Guidelines for Mining Near Surface and Underground Bodies of Water". This document was based on the work done by Skelly and Loy (under Contract No. H0252083) and K. Wardell and Partners (under Contract No. H0252021). How ever, these guidelines have limited application, because these did not (1) define the bodies of water of concern, and (2) take into account the nature of the strata being encountered. These guidelines assumed that all bodies of water which would be undermined were large. For the purposes of this discussion, water bodies may be divided into three categories, depending upon their potential to cause damage to the underlying mining activity: ? catastrophic ? major ? limited Bodies of water which pose the threat of catastrophic destruction in the mine, should there be an inrush, include oceans, large lakes, big inland reservoirs, and rivers that could flood the mine complete- ly in a short period. Those with major potential for damage would include lakes and streams which might present a danger to both life and property if not considered in the mining plans. Finite bodies of water which have a volume considerably smaller than the mine volume offer a limited potential for damage in the case of an inrush. These include flowing streams which have a relatively small rate of replenishment and which can be dealt with by pumping or isolation in the event of a breakthrough into the mine. Such bodies of water may be inconvenient and cause a temporary disruption of production, and could even cause some damage to equipment, but only in rare instances would personal injuries occur. The scope of this paper is limited to the exploitation of stratified mineral deposits with overlying -face bodies of water. Vein and dessiminate ore deposits are not discussed, nor are breakthroughs into adjacent mines in the same horizon. Overlying, water-logged strata also pose a serious threat to mining, but are not treated in this discussion. Pending further investigation these strata may be considered as bodies of water with catastrophic potential for damage, with the base of the strata being considered the bottom of the water body. When the body of water is large, so that it may cause catastrophic damage to the mine in the event of an inrush, the guidelines suggested in IC 8741 are applicable. In order to develop criteria and procedures for mining under smaller bodies of water, however, it is necessary that the nature of the strata disturbance due to underground mining be examined.

Jan 1, 1981

By B. R. Green, Ms. M. H. Kotze

Ion-exchange fibres (IEF) were prepared by the ir­radiation grafting of styrene onto polypropylene, which was then subsequently functionalized. Strong- and weak-base exchangers were prepared and evaluated Tor their ability to extract gold cyanide selectively. The IEF prepared had loading capacities similar to those of the corresponding resins and they had good selectivities for gold cyanide when contacted with a mixed metal-cyanide solution. The expected advantage of IEF over granular exchangers, that of faster kinetics, was illustrated. The strong-base Iibre in particular seemed to be very effective for the extraction of gold cyanide from dilute solutions such as return-dam waters.

Jan 1, 1990

By E. Watkins, S. J. SCHATZEL, K M. AJAYI, V. Gangrade, Z. Khademian

A stochastic discrete fracture network (DFN) model is developed based on mine site core log data to predict the horizontal and vertical permeabilities from the surface to the top of the caved zone at a longwall mining site in southwestern Pennsylvania. One hundred DFN realizations were generated to determine permeabilities for the isolated zone over an abutment pillar after mining the second panel. The results from this study show that the vertical and horizontal permeabilities from the DFN model agree closely with field measurements, which indicates that the resultant permeability obtained from the field measurements is representative of the predicted permeabilities. With this agreement, the aperture data for other zones of the mine could be obtained from the geomechanical model — specifically, for the fractured zone over the gob. Based on the successful validation of this model, this model could be further developed to predict the permeability of the fractured zone over the gob with fracture aperture obtained from the geomechanical analysis. This will complete the fracture characterization of the overburden, which could be used to predict potential shale gas flow to the mine in the event of a breach. This prediction could provide information on the associated risk of a casing breach and determination of methods to proactively prevent such an occurrence.

Feb 1, 2023

By A. Shah, L. W. Saperstein, M. C. Radomsky, D. L. Passmore

The development of microcomputer software that provides an analysis of pit-specific accident and production data for the mining industry is seen as a vital component in a total loss-control system. The Mine Injury Reporting System (MIRS) allows users to access accident and production data prepared by the Health and Safety Technology Center of the Mine Safety and Health Administration of the US Department of Labor for any particular state and to generate a simple, yet informative, report.

Jan 1, 1990

By M. L. Whisman

Radiotracer techniques were developed for stoichiometric studies of photochemical reactions associated with atmospheric smog formation. Stock blends of separate hydrocarbon and oxygenated compounds were prepared and calibrated. 14C-labeled reactants and products in reaction systems involving hydrocarbons and nitrogen oxides at the ppm level were analyzed for qualitative and quantitative data. Precision and accuracy of these methods developed by the Bureau were determined by replication and statistical treatment of data, and these methods are described.

Jan 1, 1969

By K. I. Afewu, L. C. Woollacott

Little is reported in the literature that is directly useful for the interpolation film coefficients for the in-pulp adsorption circuits used in gold metallurgy. This can create a problem if the design or operation of these circuits is to be optimized by the use of simulation techniques. To address this problem, a study was undertaken on the influence of mixing intensity, scale, and geometry on the film coefficient in adsorption systems typical of the carbon-in pulp plants used for gold extraction. This, the first paper deals with the influence of these factors on the film coefficient and shows that the specific power to just disperse the carbon in the slurry is an important variable. This variable is also strongly dependent on mixing intensity, scale, and geometry-a dependence that is dealt with in the second paper in the series. From the informatlon obtained, practical scale-up procedures were developed. These procedures are considered to be applicable to resin-in-pulp as well as to carbon-In-pulp plants.

Jan 1, 1995