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By N. R. Thote, J. L. Porathur, C. P. Verma

Highwall mining is a highly mechanized coal mining method associated with several advantages, such as a very high production rate (approximately 3,000 t/d) and low production costs. There is no requirement for underground support, ventilation, or blasting. Production leads to added recovery, which is otherwise lost in the ultimate pit. The use of highwall mining can bridge the gap that exists between supply and demand in the energy sector. This paper presents a brief review of highwall mining technology, including current status, analysis tools, and design techniques. In addition, it identifies important parameters from the analysis of failure case studies.

Jan 1, 2014

By Boyd G

This paper describes the planning, analysis, design and operational experience of highwall mining based on auger drilling techniques applied to thick coal seams exposed in an opencut highwall. Being the first time such technology has been used in Australia, a large commitment to technical design and logistics planning was given by Callide Coalfields Pty Ltd. This commitment included technical and operations management and supervision, mine services, and the retention of consultants to undertake geotechnical analysis, instrument preparation and instrument installation.

Jan 1, 1991

To maximise recovery by highwall mining, pillars must be designed which are long, slender and of relatively low width-to-height ratios. The strength of pillars with width/height less than 2 depends primarily on the mechanical response of the coal, due to the reduced influence of frictional restraint between roof and floor. A suitable pillar design approach therefore requires a method of estimating coal-seam properties. Experimental studies were carried out to determine ways of reliably predicting the large-scale mechanical properties of coal seams from small-scale test data. The studies led to a method of practical, systematic assessment of coal-seam properties based on measurement of coal rank and seam brightness profiles. The criterion employs the parameters sigma(c), m and s of the generalised Hoek-Brown empirical strength criterion for rock masses. A novel design approach combines the flexibility of modern numerical modelling programs with simple hand calculation for rapid assessment

Jun 21, 1905

By Chris Kelly

The Monroe County Quarry is an open pit granite quarry located near the town of Bolingbroke. Monroe County. Georgia. The quarry has been in continuous operation for approximately 10 years. The quarry covers approximately 27 acres and has an annual production rate of 1.0 million tons. On the morning of April 26. 2000 a sudden rapid highwall failure occurred at the west end of the north wall of the quarry pit. The failure occurred approximately one hour after a three inch-wide crack was observed in an access road located at the crest of the highwall. No indications of failure had been observed prior to the development of the crack. The active mining area had been at the base of the failed area. The pit was successfully evacuated prior to the failure and there were no losses of either personnel or equipment. The amount of failed material was estimated to be in excess of two million tons. In order to ensure a safe working environment at the quarry a slope monitoring program was established in the area of the failure. The program consisted of using an EDM survey instrument to periodically measure the location of survey prisms installed at carious points on the north wall. The locations of the prisms were recorded over several months and changes in location were analyzed in order to identify and characterize the movement of the failed mass. The results of the analysis provided a basis for recommendations regarding access to various areas of the quarry. This paper discusses the factors contributing to the failure, the method of post-failure slope monitoring, anti the interpretation of the monitoring data.

Jan 1, 2002

By Fitzhugh T. Lee

Results from the first part of a two-part investigation of the stability of highwalls in open-pit coal mines in the Paleocene Fort Union Formation of the western Powder River Basin of Wyoming and Montana indicate that these highwalls are subject to time-dependent deformation. Field investigations and laboratory physical properties tests of coal and overburden rocks suggest that several factors influence highwall stability. Some of these factors are rebound of overconsolidated rocks, desiccation, water, orientation and spacing of fractures, and strength and deformation properties. Factors of safety for a typical highwall in the study area (calculated by the finite element method) may be less than 1.0 when open fractures are present and the highwall has degraded. Although it is concluded that most open-pit highwalls in the Fort Union Formation within the study area have adequate short-term stability, these highwalls do deteriorate and become progressively less stable. Because of this, postmining failures are common and stability conditions could become critical if mining were delayed and then resumed after a period of several months. The second part of the investigation will utilize field measurements of rock-mass properties and instrumentation of actively mined highwalls to obtain data for comparison with the results of the initial investigation. Because the height of highwalls will increase as the more shallow coal is exhausted, these data will also be used to predict the behavior of slopes higher than those presently found in the western Powder River Basin.

Jan 1, 1977

By Harry L. Siebert

A major Arizona highway project is jeopardizing site safety and security because of the lane rental policy. One million cubic yards of rock must be fragmented to provide two additional lanes parallel to the existing roadway. Traffic is stopped during blasting operations.

Jan 1, 1997

By Thomas Sisley, Jozef Zurawski, Richard Switalski

Hilltop Interceptor Contract G is one of the segments of the wastewater control system in the greater Cleveland area. The tunnel is a relief interceptor constructed by the Northeast Ohio Regional Sewer District to minimize combined sewer overflows in the Easterly Service Area. The design study identified the need for a 3.35 m (132 in) diameter, 3.35 km (11,000 ft)in-line storage conveyance tunnel to be constructed at depths of 30 to 70 m (100 to 230 ft).Six structures for access, future flow drop, work shafts and overflow control were required to complete the system. The interceptor reduced the design peak flow from 12.5 m3/s(285 mgd) to 6.1 m3/s (140 mgd) by detaining in line 22,800 m3 (six million gallons) of wastewater.

Jan 1, 1997

By Lee W. Abramson

Performing risk analyses on tunnel projects has become common place and on many projects it is required from an owner or regulatory perspective. After the project is planned, designed and constructed, the data concerning identified risks, assumptions, costs, probabilities and mitigations is generally long forgotten and buried in some file somewhere. A study was performed comparing predicted risks versus actual events on several recently constructed tunnel projects. Probabilities and costs for selectively common risks on tunnel projects have been studied and re-evaluated. Conclusions are presented that can guide future projects and the veracity of the tunnel risk analyses performed.

Following extensive trials on a 100 000 tpa Research and Development facility at Kwinana, Western Australia, Hismelt Corporation (wholly owned by Rio Tinto) are confident of the future commercial success of this technology. The Hlsmelt process uses iron ore fines and non-coking coals to produce molten pig iron suitable for feeding to BOF and EAF steelmaking vessels. The unique process configuration combines direct injection of raw materials into the molten iron bath, high rates of metal and slag mixing, and effective post-combustion of the bath gases to achieve efficient coal utilisation. This is the key to the strong economic performance of the process.

Jan 1, 1999

By Mario Samamé Boggio

El presente trabajo describe el período de la Colonia dentro de la historia minera peruana. Dentro de esta época no se utilizó método alguno para su explotación y no hubo un adecuado manejo de recursos y energías. Posteriormente se describe la mita, expansión (Huancavelica, Huantajaya, Laicacota, Hualyacoc), así como se describe las minas de plata, oro, metalurgia colonial y la misión Nordenflicht.

Sep 1, 1983

By Máximo Yaringaño

El presente texto describe la historia y las exploraciones realizadas en los distritos de San Gregorio y Colquijirca. Esta última se encuentra dividida en dos partes: Colquijirca propiamente dicha y Marcapunta, que es un yacimiento diferente -en tanto se halla emplazado en rocas volcánicas, mientras que San Gregorio y Colquijirca se hallan en rocas carbonatadas. Los tres yacimientos se encuentran en los Andes centrales del Perú, en el departamento de Pasco, Junín. La mineralización de San Gregorio está alojada en las unidades carbonatadas jurásicas del grupo Pucará, en su facies occidental; la mineralización de Colquijirca está emplazada en forma de mantos plegados en rocas carbonatadas de la formación Calera, correspondientes al grupo Pocobamba, de edad terciaria superior.

Apr 26, 1999

Slide presentation at conference

Jan 1, 1996

As the theme of this conference is æRediscover OtagoÆ it would seem appropriate to revisit the era of the gold rushes and subsequent mining industry which rapidly advanced settlement and economic prosperity for Otago, and left permanent reminders in the form of historic mining sites, many of which are now encompassed within the Otago Goldfields Park. I have been invited to give a paper at this conference on the subject of æHistoric Goldfields of Central OtagoÆ. As well as having a working involvement with historic areas through my employment with the Department of Conservation, I have a personal interest in the early goldmining industry of Central Otago as my grandfather came out from Scotland in the 1890s to help construct gold dredges on the Molyneux. My grandfather made headlines in the local paper in 1920 when he believed he saw a New Zealand otter at Island Block near Beaumont - but that's another conservation trail that I will not pursue any further today! For this paper I intend to divide my time to cover the following topics. Firstly, I would like to sketch a mental picture of the characteristics that make up the Central Otago landscape, and the general perception that early miners must have had when viewing this foreign land. Then I would like to briefly discuss the changes and the consequences in the early gold rush to Central. Finally, I would like+ to discuss the establishment of the Otago Goldfields Park, which I will illustrate with several slides.

Jan 1, 1992

By David R. Maneval

At the turn of the century the keys to industrial success were coal and iron. At that time, Pennsylvania was the ranking mineral producer among the States and close to 90% of the Nations energy output was generated by coal. The growth of this Common-wealth into the greatest industrial State in the nation has been due to the huge resources of easily accessable coal found by the early settlers. It was the development of these deposits that provided the United States with a new source of fuel energy. For nearly a century, the Commonwealth was the chief powerhouse of our nation and the chief source of its industrial blood and bone. In 1928 it was truly said that coal was king in Pennsylvania. Pennsylvania that year mined a billion dollars worth of coal. A single train carrying this output would reach more than twice around the world at the latitude of Pennsylvania. Coal formed nearly 67% of the freight of Pennsylvania and was responsible for its four billion dollar iron and steel industry. Coal was the real reason why Pennsylvania although 32nd in size was second and not tenth or fifteenth in wealth, population and industry. Pennsylvania was slow to take-up her heritage as the greatest coal producing State in the union. But the knowledge that coal was present was not slow in accumulating. In fact the Indians were aware of its existence long before the white man arrived. They knew that many of the hills were underlain with black stones that would burn. It is reasonably certain that Arnold Viele, the first white man to cross the mountain in this State saw coal in them in 1692. But awareness was not enough. The population in these days was confined to southeastern corner of the State and the population at this time had little need or interest in the resources further inland. Pennsylvania anthracite was discovered in 1762 but was first regarded only as a curiosity. Commercial productions started in 1820. This stimulated the development of many native industries and extensive canal system and afterwards an elaborate net-work of railroads were constructed at great costs to bring the products of the hard

Jan 1, 1971

By G. H. Robbins

"Originally presented at TORONTO 94, CIM-AGM, this paper has been updated to reflect the present status of business development for theSO2/AIR process. The paper reviews the back-ground leading to the invention, discusses the process chemistry and historically tracks the commercial development. Engineering and cost considerations are presented.IntroductionThe year 1994 was particularly significant in terms of the technical and business development of the INCO SO2/AIR cyanide destruction process. The year marked a decade of service to the world mining community since INCO acquired the Canadian patent in 1984. In that time period, the technology had become widely recognized as the state-of-the-art process in the field of cyanide detoxification and today we enjoy the distinction of having licensed the process at over 50 project sites worldwide. The application for the process has mostly been in the mining industry in precious metal recovery plants where it offers treatment for a wide range of waste streams such as: CIP/CIL slurries, Merrill-Crowe barren bleed solutions and/or re-pulped filter cakes, tailings pond water recycle or discharge, make-up water to flotation circuits and feed to underground backfill plants. The process also applies to the treatment of high cyanide rinsewaters from metal plating shops. More recently the process is being applied to the rinsing and abandonment of heap leach pads where it has proven to be a very cost-effective application of the INCO process. The distinct advantages that have led to the success of the process are the ability to work on slurries as well as solutions and the significantly low cost of sulphur dioxide products. The process is safe and easy to manage and uses all forms of SO2(liquid, gas or salts) which gives the process tremendous versatility with respect to geographic application. Having more than ten years of service"

Jan 1, 1996

By Charles M. Keenan

THIS PUELICATION lists and provides brief accounts of the major disasters not classified as explosions of gas or dust that have occurred in the cod mines of the United States from the earliest times to the present. Together with an earlier publication of the Bureau2 it provides information on all the known major coal-he disasters (disasters causing five or more deaths) in this Nation's history. Sources of each account are given individually. In each account the actual words of the original publication are used unchanged, but sentences or paragraphs referring to details that are not significant have been omitted. In those few cases where conflicting data were reported in different publications the selected version is the one that appears most logical and which in general is in agreement with most of the other accounts.

Jan 1, 1963

By R. L. Summers

The tremendous engineering advances occurring during this past century are very evident within the boundaries of the Anthracite Section of AIME. The Steelton plant of Bethlehem Steel Corporation, located along the Susquehanna River just east of the Commonwealth's capital at Harrisburg, for more than 105 years has experienced a most dynamic life which has paralleled America's industrial growth. (Figure 1) In June 1865, just after the Civil War, a group of men met to organize the Pennsylvania Steel Company. The war had brought into sharp focus the vital importance of the railroads to the country's expansion. Until that time wrought iron rails were used, and the replacing of track after only several months wear had become an almost unbearable cost. The spirit of free, competitive enterprise and the prospects of a lucrative market compelled these men to form that first Pennsylvania Steel Company and to develop better rail products. They issued the following statement: "...our desire to free ourselves from dependence upon a foreign market (has) led to the organization of the Pennsylvania Steel Company, and the parties who have connected themselves with it are determined to produce upon American soil all the principal manufactures of steel that are now, at such a serious cost for freight, commission, insurance, exchange, duty, etc., and often, with so much delay and uncertainty, imported from abroad. (We) are preparing to establish near the consumer, works at which articles of accustomed pattern will be promptly produced, and from the

Jan 1, 1971

By Dean E. Matthews

The concept of a pile for construction is credited to a Neolithic tribe called the "Swiss Lake Dwellers" who lived in what is now Switzerland about 6,000 years ago. They used piling, not for supporting heavy loads as we do today, but for elevation to protect themselves from wildlife. The Romans often used piles, and built many structures, including buildings, homes, bridges, roads and viaducts on piling. The Romans built the first bridge across the Tiber River in Rome on timber piles in B.C. 1620. Homes in the cities of Venice and Ravenna were built on piles from B.C. 100 to A.D. 400. The Romans also built the first bridge across the Thames River in London in A.D. 60 on timber piling.

Jan 1, 2003

By Sydney H., Ball

ONE of the important mineral discoveries of the eighteenth century was , that of the Minas Geraes, Brazil; diamond fields. The production of this and of .other diamond discoveries in neighboring states made Brazil the premier producer of diamonds, succeeding India; its 140 years of supremacy finally passed to- South Africa- 60 years ago. Three times have diamonds contributed heavily to Portugal's somewhat checkered financial history; first in the sixteenth and seventeenth- centuries when the diamond trade of India was controlled by its citizens residing in ,Goa, later in the late eighteenth and the first 75 years of the nineteenth century when the Brazilian fields were the world's source of diamonds, and now, when the Angola diamond mines are the principal source of revenue of its colony, Portuguese West Africa. Certain phases in the history of the administration of the Brazilian field are sufficiently curious to warrant description.

Jan 1, 1929

By T. A. Rickard

FROM AN OLD MANUSCRIPT THE text for this contribution to the history of the Patio process is a page taken from a Spanish manuscript of Bartholomé Arzaj Sanches y Uela, now in the possession of the library of Brown University (see Figure 1). I owe the photographic print to the courtesy of the librarian. The date, as will be seen, is 1577. The subject is the treatment of silver ores at Potosi, in old Peru, but in modern Bolivia. The group of drawings (see Figure 1) is entitled "Arrangement of the machines in which the ores of silver are ground on the bank of Potosi, the one of two batteries and the other of one". First, top-left, we have the sketch of a "machine of one battery" operated by a water-wheel. From this mill the water runs in part along an aqueduct supported by pillars to the two-battery mill and in part down the hillside, where men are at work with "tubs, which are called cochas, in which are washed the charges of ore and amalgam". Along the top of the page are shown the "various offices in which are stored the copper, the salt, the ucha [llama dung, used for fuel], the lime, and other materials for the re-duction of the ores". To the right of these are "apartments and warehouses in which is stored the ore brought down from the mountain"?the cerro de Potosi. Through the arched portal come the "sheep [llamas] on which is brought down the ore". To this is added a reference to "the second gate, which closes the whole works". On the level above the aqueduct are seen six men carrying skin-bags that contain water. This is being sprinkled on the ore. On the extreme right are six more of these water-carriers. Next comes the two-battery mill. The mortero, or mortar, is marked on the right. Another description says, "Stone, on which the stamps crush the ore, which is called a mortar". To the left of these are indicated "screens of wire in which the ore is sifted after it has been crushed". Farther to the left, near the ore-washers, is a "shed, in which is placed the metallurgist to test the ore of the boxes". Along the left side of the page are sundry buildings, one of which is labelled a "shed in which are placed the cones of silver". Near it, lower, to the right, is the "furnace, in which are roasted the sulphides to facilitate treatment". Farther to the right is the "place where the Indians mix the charges of sulphide ore, which is called a buitron". Alongside is a "buitron in which the charges are prepared for reduction". Inside is a container, to which are attached the words "measure, called topo" On the extreme right is "another buitron in which the Indians mix the ores with their feet, as well as the heaps for the preparation of the reduction". Near the bottom, on the extreme left, is the "chapel where the holy sacri¬fice of the mass is celebrated". Under the first buitron is the "place where they dry the moist ores, called pãpear".

Jan 1, 1935