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By M. M. Zarnan

This paper presents the results of s study involving characterization of ground subsidence of abandoned lead-zinc mines in northeastern Oklahoma. Two coordinated efforts were undertaken: (1) collection and analysis of available data such as driller's logs, geologic cross-sections, structure contour naps and stratigraphic sections, and (2) development of a numerical (finite element) technique for prediction of collapse and mine subsidence. An in-depth analysis of a major collapse in the region was conducted. The factors which contributed to this collapse were identified.

Jan 1, 1989

By E. J. Kloos

The Bureau of Mines developed a test for evaluating gas masks designed to protect against phosphine gas; phosphonium iodide is used as a source of phosphine. Gas masks approved by the Bureau for respiratory protection against phosphine include the GMC-SS-1, Mine Safety Appliances Co.; the LG-10 and LG-10G, Willson Products Division, The Electric Storage Battery Co.; and the 084-PHOV-R, Acme Protection Equipment Co.

Jan 1, 1966

By Alex Moyano

The Peirce-Smith converters are traditionally carrying out the converting process of a copper matte in the smelters of Codelco-Chile. However, its production increment is very limited due to the investment magnitude associated to the fulfillment of the environmental regulation. The objective of this paper is to present the Codelco continuous converting process technological advance when converting mattes and/or white metal into blister copper in a Teniente converter unit as an alternative to increment the corporative anode copper production. In 1994, Codelco-Chile started evaluating its ?home made technology? as an alternative to the traditional batch-type converting process. By the year 2001, the Caletones smelter converted liquid white metal to blister copper in a rearranged PS converter continuously. Then, during the 2001-2003 period, several pilot and industrial scale tests were done in a Teniente converter unit at Codelco Norte smelter, evaluating the continuous converting process, i.e., processing liquid mattes (62-68% Cu) to blister copper, demonstrating its technical feasibility with: (i) both constant production of gas flow and SO2 concentration, (ii) production of liquid slag, and (iii) production of a clean blister copper, suitable for the refining process. The promising results have led Codelco-Chile to plan for the 2006 period, a next advanced stage for the continuous converting process evaluation by carrying out a new campaign of tests in a Teniente converter unit at the Codelco Norte smelter.

Jan 1, 2006

By E. O. Mixon, Joseph P. Sehulster

This paper describes the driving of a 1421 m long by 2.74 m diameter sewer tunnel in postglacial soils of the Menomonee River Valley in Milwaukee, Wisconsin. An earth pressure balance machine was used for excavation and to install a "one pass" pre-cast concrete gasketed segmental liner. Also discussed is the use of ground freezing to stabilize the ground for the start of tunneling operations and modifications made to two structures to accommodate final tie-ins for the sewer tunnel.

Jan 1, 1989

By Mark G. Lafontaine

Underground 802.11 wireless communications has become widely adopted for automation and communication purposes but maximizing the wireless signal presents many obstacles given the harsh environment as well as the presence of materials and conditions that can reduce signal propagation. Changes in elevations and curvatures in ramp to drift transitions also affect the wireless signal. Based on the requirements of wireless applications such as voice, data, or location tracking, the wireless site survey is the key tool for measuring and predicting signal strength and signal-to-noise ratio. These readings help determine the maximum distance between access points in order to sustain an overlapping wireless signal where required. This paper describes the methodology and tools used for measuring 802.11 wireless signal strength in an underground mine environment in Northern Ontario. The physical characteristics of the mine and the actual recorded wireless signal data will be presented in order for the audience to gain an understanding of the factors that affect signal throughput. Antenna selection used for the site survey will also be discussed as it played a key role in propagating the wireless signal.

May 1, 2013

Throughout the Kalgoorlie Field the dominant factors influencing all planned exploratory work are: firstly, the general geology of the district, and, secondly, the lode fracture pattern. Superimposed on these, there are innumerable faulting problems which tend to complicate the search for ore.In this paper it is proposed to deal primarily with the lode fracture pattern and to touch on the general geology only insofar as it affects ore distribution. So much has been written on Kalgoorlie geology that it would be impossible to review the literature adequately in a brief paper such as this. The basic facts of rock types and rock distribution are well established and the broad structure of the field is known in the central portion, though it is less well established towards the northern and southern ends.The latest descriptions of the general geology are those of Stillwell (1), and Gustafson (2), -and these represent the basis of current knowledge.GENERAL GEOLOGY.The field is six miles long and about one mile wide, the long axis trending north-west. The "Golden Mile," or heart of the mining 'area, covers a length of three miles in the southern section, and consists of a central core of quartz dolerite greenstone which merges into uralitic quartz 'dolerite on its western margin. The uralitic quartz dolerite is derived from an original quartz dolerite by a low grade...

Jan 1, 1948

By Keith Kern, Joseph P. Matoney, Kenneth E. Harrison

INTRODUCTION "When there is an economic need for cleaning fine coal to low ash, the technical difficulties will be solved. The utilization of fines below 28 mesh will determine the degree to which beneficiation will be carried. Whenever these "fines" will be processed into smokeless fuels or used as new materials for the chemical industry or for hydrogenation, a higher degree of cleaning will be economically justified”.(l) This quote from the 1943 edition of Coal Preparation correctly anticipates the use of fines as "smokeless" fuel or as a future component of boiler fuel and a1 so as a raw material for the chemical industry or possible new uses such as for internal combustion engines. Fines utilization depends upon an economic need and possibly neglects to say an environmental need or a government funded development program as the prime mover for development. In any event, this conference is faced with the "need" to beneficiate fine coal and undoubtedly among the processes that will be discussed are the unit processes of future coal preparation facilities. HISTORY OF DEVELOPMENT It is interesting to look at where we have been, where we are now and where we possibly will be in the future. In order to put some limitations on this presentation, we will for the most part confine our remarks to this century and particularly developments since World War II. We also will limit our remarks to the preparation of bituminous coals in the United States, and for the most part, to wet processes. In the 1943 edition of Coal Preparation, clues to the processes being used to beneficiate coal are contained in the Chapter Titles. An extensive treatment of "Hand Picking" was contained in Chapter 8. Chapter 7 contained a description of methods for "Preparation at the Face". Chapter 18 dealt with "Slurries, Sludges, Slimes and Water Treatment" and defined this size of coal as being the size at which "Jigs and Chance Cones are usually dispensed with and other methods such as the hydrator, tables, and froth flotation are employed. Generally the limit is 1.7mm to 3.4mm. In the days before World War I1 the then modern bituminous coal preparation plant contained jigs or Chance Cones for the coarse material +6.35mm, concentrating tables, launders or some classifier type of coal washer for the fines (6.35 x 0.15mm), and froth flotation as the only method of cleaning minus 0.15mm coal which was used very sparingly.

Jan 1, 1988

J. A. Mathews,* Syracuse, N. Y. (written discussion?).-It is interesting to note how frequently we hear of some process that is going to revolutionize the tool-steel business. I don't know why it is, but every one seems to have it in for us poor tool-steel men. About 15 years ago, a good-sized plant was built in Syracuse for the manufacture of cast tools of malleable iron. The promoter of the scheme claimed to have a secret, process that had been given to him by a tramp to whom he gave a lift along a dusty road. The widows and orphans invested liberally in the securities of the company without consulting the men established in the machine-tool business in Syracuse. About two years later, when the sheriff's sale occurred, the secret, which was carried on the books of the company as an asset valued at $2,000,000, brought $15 at auction. A little later another concern started on the theory of replacing scrap high-speed steel with new high-speed steel tools made therefrom. All the tool-steel companies have made a practice of purchasing high-speed

Jan 5, 1919

By S. E. Daniel

"Due diligence reviews are an essential part of mineral property acquisitions. One of the primary reasons to complete an environmental review prior to exploration property acquisition is to assess the potential environmental liability. It is critical to identify the potential reclamation costs or existing environmental liability associated with the exploration property. A review of the existing condition of the property and its history can allow prioritization of exploration targets and ease future expenditures for historic damages. IntroductionIn Canada and some other jurisdictions, the purchaser of a property is assumed to know, and is (in the absence of deceit or fraud) financially responsible for, what is purchased. A plea of ignorance, at least from the perspective of environmental liability, is not an acceptable excuse to avoid responsibility (Nelson, 1994). Therefore, if an exploration company (for the purposes of this paper, any organization conducting exploration work) purchases a property that has environmental contamination, the new owner is liable for the cost to reclaim the site to an acceptable level. The cost to reclaim the site is the environmental liability. The new owner is responsible for existing environmental liability of the property, even if the exploration company’s personnel were not aware of the problem. In simplest terms, buyers beware. Therefore, in order to protect the exploration company’s interests, the exploration manager should determine the characteristics of the property of interest prior to purchase or other involvement, and exercise due diligence.The term “due diligence” is often used in the mining industry. To ensure clarity, in this paper’s context, the author has chosen to use the following meaning: “… due diligence is used to describe a detailed data review, generally in connection with the purchase or sale of a mineral property, the approval of a large capital expenditure, or the borrowing of a large sum of money” (Smith, 1997).Directors of the exploration company are held liable for the decisions made, unless they have relied in good faith on,“…a written report of the auditor, or a report of a lawyer, accountant, engineer, appraiser, or other person whose profession lends credibility to a statement made by any such person” (OBCA, 1994)."

Jan 1, 2003

By Arvindh Gupta

BC Hydro proposed to improve the stability of the existing Seven Mile Dam with 54 corrosion protected, re-stressable anchors comprising 92/0.6? strands each, in phase 2 of the program. Being globally the largest capacity anchors ever build, coupled with extra ordinary specifications, the project was a challenge for the entire post tensioning industry. The paper discusses the challenges associated with the anchor material supply as per specifications, extensive research and development carried out by Con-Tech Systems ltd. to overcome the challenges and contribute in making the project a success. The substance of this article is published in the Aug/Sep issue of ADSC magazine.

Jan 1, 2004

By J. B. Zadra, S. M. Shelton, M. M. Fine

"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 large deposits of low-grade ore in the United States, the production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stockpiled ore is depleted through inability to procure adequate supplies from foreign sources. Consequently, a program of laboratory and pilot-plant investigation 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 woo set up to direct and supervise the work were discussed in the foreword of the first paper of this series, Report of Investigations 3606, Manganese Investigations. 1. Concentration of Manganese Ores from the Drum Mountain District, Utah, by S. R. Zimmerley, J. D. Vincent, and C. R. Schack. Other reports will be published as the work progresses."

Mar 1, 1942

By Enrique Levy

The publication from which this paper was abstracted is the first at-tempt to correlate all the metallogenic deta compiled by the author for the preparation of the 1:2,000,000 Metallogenic Map of Central America. It is not a treaty of metallogenic theories but rather a careful effort to postulate metallogenic provinces and epochs with the intention to stimulate other geologists and mining companies familiar with the area to criticize and improve on the ideas proposed. The sole purpose being to find new mineral deposits for the betterment of our people.

Jan 1, 1971

Feeders and Grizzlies are links of the utmost importance in the chain of milling operations, but, hitherto, the close analysis granted to other equipment has been withheld from these machines. The development of. the self-clearing drop-bar feature, the result of many years' practical study of the problem, has made possible a machine which will

Jan 5, 1918

By Feng Junfa, Du Feng, Li Huamin, Syd S. Peng

"The Ordos coal field is located in the northern midwestern part of China (Fig. 1). Since the mid- 1980s, it has been developed into one of the major coal fields in the world, producing approximately 833 Mt (918 million st) of raw coal in 2013. There were once more than 400 coal mines operating in the region. However, due to the combination of market conditions and implementation of government consolidation policies, the number of coal mines operating in recent years has been reduced considerably, with increasing output.The surface of the Ordos coal field is covered with loess and alluvium layers of varying thicknesses. In many areas, their combined thickness may amount to as much as 100 m (328 ft) underlain by thin bedrock. Many loess and alluvium are aquifers receiving water from rainfalls. There are also gullies of varying depths crossing the coal field. Figure 2 is a typical stratigraphic column highlighting the coal seams and roof and floor rocks of interest.In conjunction with the development of highproductivity coal mines, numerous ground control instrumentation tests have been conducted in the operating longwall panels. Analyses of the results of those tests offer the opportunity to understand the effect of wide-ranging mining and geological factors on the overburden movement. For this reason, trips were made to coal mines of interest to interview mine management and collect their unpublished internal research reports on ground control instrumentation. In addition, literature searches on published thesis/dissertations and papers in the professional journals were performed. Finally, data from a total of 95 fully mechanized longwall panels were collected. The instrumentation involved primarily the monitoring of hydraulic pressures of longwall shields, from which the first roof weighting and first roof caving interval and periodic roof weighting and periodic roof weighting interval were identified and determined. Some panels also included measurements of roofto- floor convergence at the face, roof strata bed separation, longwall face sloughage and the height of caving and fractured zones in the overburden. Those 95 panels were located in 20 coal mines (Fig. 1) congregated along both sides of the Wulunmulun River with the following mining and geological conditions. All together those 20 mines produced more than 224 Mt (246 million st) in 2013, accounting for approximately 27 percent of the total coal production in the Ordos coal field:1. Period of mining: 1991-2013.2. Mining methods: All panels employed the one slice, full-seam natural-caving longwall mining method like those practiced in the United States. All panels were developed with a twoentry system with a single-row of chain pillars measuring 20- x 20-m (65.6- x 98.4-ft) wide.3. Coal seams (Fig. 3): Coal in Ordos coal field is high-quality steam coal, that is very low in sulfur, potassium and ash, but high in Btu. Data were collected in panels mined in a total of 10 seams with 82 panels in four seams and the remaining 13 panels in six seams. The first six seams (1-2, 2-2, 3-1, 3-2, 4-2, 5-2) were mined by the Shenhua Coal Group (the world’s largest coal company) and the #4-2, 5-2, 6R, 62, and 62R seams were mined by both the Shenhua and Yitai Coal groups. In each coal group, the sequence of mining was in descending order. For example, in Shenhua Group, the top seam 1-2 was mined first, followed by the 2-2, 3-1, 3-2, and 4-2 seam in that descending order. In Fig. 3, the top-down sequence of coal seams is listed from left to right in each coal mine group. All seams were near horizontal with dip angles less than 3°."

Jan 1, 2014

By M. M. Leighton

THE engineers of Illinois have been submitting to the State Geological Survey an increasing number of requests for advice on their geological problems, including landslides, unequal settling of fills, laying pavements across peat bogs, shattering and heaving of pavement by frost action, etc. The authors discussed the behavior of landslides, their effects, their causes, a tentative classification, and remedial measures. In the latter connection the efficacy of drainage and how it should be handled in order to be most effective was considered. The principles and efficacy of other remedial measures, such as subsurface blasting, rock anchoring, installation of wood, concrete or steel piling, construction of retaining walls, construction of cribbing and reduction of slope were also discussed. Attention was also given to the matter of applying geological knowledge to avoid undesirable highway locations, and a specific example was cited.

Jan 1, 1929

By J. F. Smith, J. R. Ogren, N. J. Magnani

The uapor pressrcres of magnesium over binary alloys of magnesium with twelve of the yare-earth eletnetzts have been measured by the Knudsen effuion method in the temperature range 675° to 910°K. These vapor-pressure measurments were combined with data concerning the tevtrlitzul magnesium solubility and the vapor pressure of pure magnesinm to evaluale the standuvd free energies of pluase jormation. These free-etzergy values indicate that the CsCl structures of the heacy rave earths tend to be somewhat less stable than those of the light rare earths. This dif-]eying- behaviov covrelates with differences which have been obsevz~ed in other alloy systetns wherein a phuse appeurs, disappeavs, or changes crystal stvucture as the atomic number of the rare-earth com-ponent is changed. This behauior also appears to correlate with the struclurul rariations within the rare-earth elements themselves, and it is speculated that cariations in the spatial extent of the 4f orbitals are responsihle. STUDIES of the phase relationships and crystal structures in the binary systems between rare-earth metals (lanthanons) and magnesium are extensive but far from complete. However, the currently available information1-10 does produce a rather interesting pattern. This is illustrated in Table I. If one excludes europium and ytterbium from consideration because of their generally atypical behavior, it can be seen from the table that the phase relationships in the magnesium-rich regions show a distinctly different pattern for the lighter lanthanons as compared to the heavier lanthanons. For the lighter lanthanons, LnMg2 phases occur from lanthanum to gadolinium with the cubic MgCu2 structure, LnMg3 phases occur from lanthanum to terbium with the BiLi3 structure, and magnesium-rich phases occur from lanthanum to gadolinium with stoi-chiometries between Ln5Mg42 and LnMg12. In contrast, for the heavier lanthanons, those LnMg2 structures which have been examined have the hexagonal MgZn2 structure, LnMg3 phases have not been observed beyond terbium, and the magnesium-rich phases occur with the a manganese structure near a stoichiometry of Ln5MgZ4. The heavy lanthanon-magnesium systems thus appear to be analogous to the Y-Mg system""2 wherein YMg has the CsCl structure, YMg2 has the MgZn2 structure, and the region Y4Mgz5-Y5Mg24 has the a manganese structure, and no other intermediate phases are observed. Similarity in alloying behavior between yttrium and the heavy lanthanons occurs commonly, and on this basis it seems likely that LnMg2 phases will be found with the MgZn2 structure in the binary systems of dysprosium, thulium, and lutetium with magnesium when the appropriate investigations are made. In the case of the magnesium-rich phases of the lighter lanthanons, only the Ce-Mg phase relationships have been investigated thoroughly and in detail, and until similar investigations are made for the other systems there will remain questions as to which magnesium-rich stoichiometries represent equilibrium phases and what systematic variations occur in the sequence from lanthanum to gadolinium. Thus the data in Table I show that only the LnMg phases occur with the same crystallographic structure throughout the sequence from lanthanum to lutetium. It was speculated that the relative stability of these LnMg phases might vary from one lanthanon to the next in such a way as to presage the differences which occur among the more magnesium-rich lanthanon-magnesium phases. On this basis the present investigation of the thermodynamics of phase formation was Gndertaken for the LnMg phases. PROCEDURE AND RESULTS A generalized phase diagram for the lanthanon-rich portion of a lanthanon-magnesium alloy system is shown in Fig. 1 where ß represents a high-temperature bcc

Jan 1, 1968

By C. Carreno, A. D. Gonzalez Escarcega, M. A. Neri, A. Martinez –Villafane, O. Cobarrubias-Alvarado

"Waspaloy is a superalloy used to manufacture some aeronautical parts subjected to high temperatures and stresses. During thermo-mechanical processing cracks are generated, causing some parts to be rejected. In order to determine the causes of these cracks, this alloy was characterized using techniques such as chemical analysis, optical microscopy, scanning electron microscopy, and EDX analysis. Heterogeneous grain sizes in the microstructure cause a non-uniform strain distribution in these parts, creating cracks in zones with different grain sizes.IntroductionNickel-base superalloys are important materials for high-temperature service applications. The manufacture of components from these materials is typically based on solidification or powder-metallurgy processes [1]. Solidification techniques comprise either the direct casting of parts or the casting of ingots which subsequently undergo a series of thermo-mechanical-processing steps to refine the microstructure. During solidification, microsegregation is usually unavoidable. The primary solidification product is a disordered nickel solid solution with an fee crystal structure (?). In many alloys, the material which solidifies last is a mixture of ã and an ordered fee phase (? '). In prototypical nickel-base superalloys, the ?'-phase is Ni3(Al,Ti) [2-3].Waspaloy is a superalloy that is used in demanding high-temperature environments in which good creep and fatigue resistance are required. One of the most common applications of Waspaloy is for turbine engine rings. To ensure the required mechanical properties, the rings are usually forged and heat treated (Figure 1). Two distinct types of microstructures are usually found to be attractive for such applications: a) A microstructure with a grain size of ASTM 10 to 14 for tensile strength, ductility, and resistance to crack nucleation in low-cycle fatigue; or b) A microstructure with a grain size of ASTM 4 to 8 required for creep strength and resistance to crack propagation [4]. Because it is impossible to refine the grain size through heat treatment, a skillfully designed forging process is crucial for the control of the grain size and, hence the properties of the forged ring [5-6]."

Jan 1, 2012

By P. B. Liebermann

1. Haulage Tests on Coal-mine Cars THE haulage of coal from the face to the tipple is an important enough link in the production of coal to deserve its full share of study and care. In order to obtain a better understanding of mine haulage conditions, a series of tests and investigations has been made which promises to hasten the improvement of present conditions. For hauling coal through the mine and on the surface, locomotives are required, the size and power consumption of which depend on the resistance to motion offered by the mine cars. This resistance is principally caused by gravity and hearing friction. The effect of gravity can be reduced to a minimum by a suitable layout of the haulageways; that is, by arranging the grades in favor of the loaded trips, and by fixing the percentage of grade to that value which gives the lowest power consumption for loaded and empty trains. The bearing friction, which is considerably greater than is generally realized, can be easily reduced to a negligible quantity by the installation of a suitable anti-friction bearing that will stand the rough use and abuse of coal-mine service. The present investigation will deal with flexible roller bearings in comparison with ordinary plain bearings.

Jan 7, 1917

By Robert A. Irvine

Traditionally, cost effective gains in the capacity of material handling systems were a result of increases in equipment size. In general, the use of maximum capacity components in a system optimizes the production "costs per ton." The trend-"Bigger is Better" will continue in material handling equipment. Since it is rare for plant operators to lament an over abundance of screening capacity, one can safely predict that vibrating screens will follow this trend. Large Vibrating Screens - The Challenge Large vibrating screens represent a unique challenge for Manufacturers, Plant Designers, and Plant Operators. The inherent mode of operation for vibrating screens is self-destructive. More often than Manufacturers admit, Designers plan for, or Operators staff for, a vibrating screen succeeds and self-destructs. This is a problem. It can magnify with larger vibrating screens.

Jan 1, 1983

By A. S. Usrnani

Due to both turbulence and the highly variable geometry of castings, a realistic numerical simulation of the metal flow is prohibitvely expensive with current technology. However, when the chief purpose is to achieve realistic thermal fields a precise How simulation is not necessarily required. In this paper we assume a laminar flow regime and obtain the flow field by solving the incompressible Navier-Stokes Equations using a velocity-pressure segregated semi-implicit finite element method. The free metal surface is predicted by advecting a pseudo-concentration function via the computed How field. This involves an explicit finite element solution of a pure advection equation. The thermal field is calculated by solving the convective-diffusive energy equation by an explicit finite element method using the computed flow field and the location of the free surface. All the advection terms are discretized using a Taylor-Galerkin method. The interface between the metal and mould is modelled using special interface elements. The model is demonstrated by solving practical example problems. The results show that a sharp thermal front is maintained during the course of filling without excessive diffusion. The heat diffusion in the mould can be controlled by varying the metal mould heat transfer coefficient.

Jan 1, 1994