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By E. D. Stephenson

As part of the British Steel Corporation?s development plan during the 1970?s, it was decided to concentrate its bulk steelmaking processes based on the BOS at 4 major Works with access to deepwater ore terminals, for the supply of high-grade imported ores. These 4 sites were at: - 1. Rarenscraig Works in Scotland where the ore terminal would be hilt at Hunterston on the west coast some 50 miles away. Bavenscraig was already an integrated Works but suffered from having to discharge ore 27 Glasgow tenxinus on the River Clyde, which could only accommodate vessels up to 25,000 tonnes. In the future, ore was to be unloaded at Runterston and shipped by a rail-link into Ravenscraig, The new ore terminal would have the potential to unload vessels up to 300,000 tonnes. - 2. Port Talbot Works in south Vales where the existing harbour was developed to discharge large ore carriers. This again was an existing Integrated Works and the benefits of the new harbour also applied to Llanwern Works which was another integrated Works some 50 dies to the east, which would now receive ore from Port Talbot.

Jan 1, 1980

By C Katonga

Mindola mine is currently the deepest mine in the Zambian copper belt. Stoping is currently active to 1330 m below surface with long range plans indicating future production from 1590 m level. The orebody is tabular and dips between 55o to vertical. The thickness varies from 8 to 14 m. The vertical crater retreat method of mining was first introduced at Mindola mine in the late-1980s following several trials that helped define the design criteria for its application. Over the last ten years the method has been continually modified to improve safety and maximise ore production. For example, due to the weakness of some rock units within the orebody formation and the instability of the hanging wall, the last VCR slices are usually between 8 - 10 m thick, and efforts are being made to strictly apply shrinkage method in order to reduce dilution. Recent advances in mining technology in the areas of equipment, blasting techniques, rock mechanics and materials handling have been employed to increase the overall productivity of the mine. Large down-the-hole machines capable of drilling 165 mm diameter blast holes, up to 80 m long are used in stoping. Each stope produces up to 20 000 tonnes of ore per month and can last for three months. Heavy systematic ground support of VCR development has significantly enhanced safety for mining crews and equipment. Crater mining has not only improved productivity and enhanced safety, but also overcome various problems associated with conventional sublevel open stoping previously employed at the mine. This paper discusses the technical and operational aspects of vertical crater retreat mining at Mindola mine during the last ten years. The changes in mining method are often accompanied by changes in mine design, blast design, mining equipment, ground support and operating practices.

Jan 1, 2000

By S. P. Kinney

The efficient operation of a blast furnace is primarily dependent upon efficient contact between the descending stream of solid materials and the ascending stream of gas. The United States Bureau of dines is conducting a program of research dealing with the interior of the present-day furnace. The work is being carried oat by.(1) observations on commercial furnaces end (2) experiments in the laboratory. Through the courtesy of the officials of the Illinois Steel Co. it was possible to make a detailed investigation of the interior of the shaft of Number.4 furnace at the company's South Works, South Chicago, Ill. The experimental work is to be reported in a U. S. Bureau of Mines bulletin which will include the results of several thousand observations on the interior of the shaft of this furnace. Such of the data as are presented later in this paper constitute only a brief summary.

Jan 1, 1929

By B. J. Moore

This publication contains analyses arid related source data for 274 natural gas samples from 20 States. Of the total samples, 269 were collected during calendar year 1985; the reminder were collected earlier, but releases granting permission to publish were not received before 1986, All samples were obtained and analyzed as part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by mass spectrometer and chromatograph.

Jan 1, 1987

By D. Harrington

This circular is part II of a series of papers reviewing the literature on air conditioning in mines with particular reference to the health, safety, and efficiency of employees. It deals with the physiological aspects of the principal physical qualities of mine air; part I (Information Circular 7001), chapters 1 to 3, discussed the physiological aspects of the chemical qualities of mine air, especially when contaminated with organic matter and noxious and toxic gases; part III will describe theoretical and practical methods of air-conditioning mines to try to correct or alleviate the conditions mentioned and will discuss the results attained by some of the systems now in use in various parts of tae world. With the present emphasis on the necessity for preserving the health of the Nation's defenders, industrial as well as military, attention should be called to the various conditions that may affect adversely their health and efficiency. One of the most important of these is exposure to abnormal air conditions, especially high temperatures and humidities. Therefore, it is believed that although the data presented here on the physiological effects of exposure to high temperatures cue intended mainly for the mining and allied industries, they are applicable to many other defense industries as well as to conditions present in some activities of the Army and Navy.

Jan 1, 1941

By L Dawson, S Carr-Cornish, N Boughen, K Moffat, S Masterson

The risk and consequences of community rejection and loss of a social licence to operate is well articulated (Moffat et al 2018), however, the means for systematically managing this risk are less established. At the local scale, a mining operation is said to have a social licence to operate (SLO) when it achieves ongoing acceptance or approval from the local community and other stakeholders who can affect its profitability (Graafland, 2002). Without this social acceptance, it is very difficult for a business to operate effectively or profitably. It is well understood that social (or community) acceptance of a mine and its associated operations is a reflection of the quality of the relationship a company has with their host community (Thomson & Boutilier, 2011; Lacey & Lamont, 2014; Parsons et al., 2014; Moffat et al., 2015). Community relations are an integral part of successful mining operations and where these interactions are effective, they tend to foster mutual understanding, trust and support between a company and the host community (Kemp et al., 2006; Holley & Mitcham, 2016). Research further demonstrates that where such interactions are perceived to be procedurally fair, the increased trust created in these company-community interactions tends to lead to higher levels of acceptance of mining operations (Moffat & Zhang, 2014; Lacey et al., 2017).The challenge, however, is how to listen systematically to communities that mining and associated operations; communities that are often located across vast geographic areas and with diverse demographics. To date, traditional methods deployed to both guide and evaluate community engagement and social investment activities have been challenged to reflect the nature of the phenomenon they seek to observe, the voice of community. For example, detailed baseline surveys of community attitudes every three years by companies, as is the requirement within the policy frameworks of most large miners, provide rich insights but do not reflect the dynamic, temporal nature of the relationships that underpins their SLO. These processes typically are largely opaque to communities and distinct from the company’s engagement activities. The CSIRO Local Voices project was developed with Rio Tinto to go some way towards meeting this challenge of how to listen to the voice of community systematically. CITATION:Moffat, K, Dawson, L, Carr-Cornish, S, Boughen, N and Masterson, S, 2018. Listening to Local Voices – a systematic approach for understanding what a social licence to operate means for Rio Tinto in the Pilbara, in Proceedings Life-of-Mine 2018, pp 8–11 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

APPENDIX C - HOISTING SYSTEMS - AVAILABLE EQUIPMENT C 1 - Introduction A survey has been made of available hoisting equipment which has applications for use in metal and non-metal mine emergency escape hoist systems. The information was gathered from a number of sources, including representatives in the USBM and MESA, mine operators, personal visits and telephone interviews with manufacturers, field visits to inspect equipment, advertisements, catalogues and indices of manufacturers. Wherever possible, technical specifications and prices were checked out with the manufacturer, or supplier. The sections on individual sub-systems and components, such as automatic control systems, winches and controls, are not intended to be all encompassing surveys. Rather a reasonable number of representative units in each category are discussed. The sample is large enough to provide a general picture of the kind of equipment available, including the abilities and limitations and a reasonable price range. The survey has been divided into six categories 1. Complete Hoisting Systems A Above ground installations B Below ground installations 2. Hoist Assemblies ^(Man-rated) 3. Hoists (not Man-rated)

Jan 1, 1976

By Fidel Torres Inga

El presente texto describe la aplicación de las pruebas con sistemas de iniciación electrónica en la Compañía Minera Suyamarca – unidad Pallancata del grupo Hochschild. Los exámenes se desarrollaron entre diciembre del 2010 y enero del 2011. Los parámetros técnicos evaluados en las pruebas son: el avance efectivo de la voladura, sobrequiere y medias cañas y el costo de extracción de material minado, perforación y voladura.

Apr 1, 2012

By R. D. Groves

Laboratory research has demonstrated that high - grade copper powders can be produced under controlled conditions from cement copper products . The technique should enable small producers to prepare a directly marketable product by means other than smelting and electrolytic purification . A continuous drum- type precipitator was the preferred unit for producing fine - sized particles of cement copper that were further processed by chemical digestion in a copper sulfate solution , by reduction and sintering in a hydrogen atmosphere , and by grinding to a powder . The effects of variables related to all stages of the process were investigated . Treatment of leach solutions from three different sources resulted in copper powders containing 99.2 to 99.8 pct Cu , apparent densities of 1.97 to 2.25 grams per cu cm , good powder flow rates , and a size distribution of 54.9 to 60.1 pct minus 325 - mesh material .

Jan 1, 1964

By D. E. Sullivan

The Minerals Availability Program of the Bureau of Mines conducts cost evaluations of current and potential mineral operations in the United States and foreign countries. The International Mining Cost Indexation System (IMCI) allows data of different time periods within a country to be updated to a common base year for analytical purposes. The IMCI comprises 12 factor cost indexes and an exchange rate series for 96 market economy countries, denominated in both local and U.S. currency. The IMCI for each country contains 12 time series indexes that measure the average annual rate of change in the cost of factor inputs to the mining industry within that country. Mining industry factor cost indexes include wages, plant and equipment, construction and mining materials, power and transportation, and other measures considered to comprise the majority of capital and operating costs. Cost data or proxies are collected in local currency. Index series within each country are constructed separately and indexed on a 1975 base year. The local currency index is converted to a U.S.-dollar-based currency index using an exchange ratio.

Jan 1, 1987

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

2, Survey of Representative Group of Metal and Non-mental Mines Before proceeding to develop and analyze Emergency Escape System Guidelines, it was necessary to obtain a broad range of information, including both fact and opinion. Although there were many areas to consider, the surveys had three primary goals 1. To determine the current state of underground escapeway planning and execution in American, metal and non-metal mines. 2. To determine, for a wide range of mining conditions, what difficulties can be encountered in complying with present and proposed escapeway regulatory standards. 3. To determine what improvements could be made and what equipment and technology was available to aid in implementing these improvements. To accomplish these goals, three major surveys were undertaken¬ 1. Survey of MESA and State Mining officials, discussed in Section 2. 1. 2. Survey of representative U S metal and non-metal mines, discussed in Section 2. 2. 3. Survey of manufacturers supplying equipment, primarily hoisting, suitable for use in escape systems, the product information which was obtained is discussed in Section 7.

Jan 1, 1976

By SME SME

NORTH AMERICAN TUNNELING 2024 PROCEEDINGS

Jun 23, 2024

By José Adachi

La ventilación de minas es un proceso relacionado a la dinámica de la mina que genera el acondicionamiento del aire circulante a través de las labores subterráneas. Como tal, los requerimientos de la mina se adecúan de acuerdo a la estructura física de la misma. En consecuencia, no existe un sistema de ventilación estático puesto que los sistemas requieren de constantes monitoreos y ajustes para alcanzar una ventilación óptima. Así, el presente trabajo señala los aspectos importantes del diseño de ventilación principal de la mina Condestable realizado entre el período de 1992 y 1993 por encargo de la compañía minera. La metodología empleada comprende mediciones de campo y el cálculo de requerimientos del caudal. Asi también está la construcción del modelo de red de ventilación y el diseño del nuevo ciricuito con ventilación forzada.

Nov 24, 1993

By Robert Linton

AT its meeting on May 21, the Board of Directors approved the recommendations submitted by President Lovejoy and named a nominating committee for the year that is especially well distributed as to major technical interest and as to geography. As may be seen from the list published herewith, two come from the East, two from the Midwest, and three from the far West. Mr. Linton, the chairman, has been a valued member of the Institute for 36 years. A memorandum drawn up by Paul D. Merica, representing the A.I.M.E., and W. R. Barclay, representing The Institute of Metals of Great Britain, setting forth a reciprocal plan for special memberships in each Institute for members of the other, was discussed. Both societies already have formally approved the plan in principle and Dr. Merica was clothed with full authority to agree on a few small details that have not been settled, and conclude the arrangement in behalf of the Institute.

Jan 1, 1936

Since 1865 when Congress moved to create a Federal Mining Bureau, successive legislations have given rise to the current '!Federal Coal Mine Health and Safety Act, 1969. Coal beds from 22 feet to 20 feet thick are mined under covers from 50 to 2800 feet with full and partial pillar recovery equally popular and accounting for a total of 54% of the mines. Pillar recovery and roof support practices vary, and each operator must submit an overall roof control plan (within specific guidelines) for approval before undertaking any development. The guidelines relate to dimensions of openings, details of support, sequence of extraction, limits of extraction and caving details. Experienced and professional staff of M.E.S.A. provide roof control plans and make inspections and grant-approvals of principles of support and minimum support in pillar extraction, with provision for modifications with time. Guidance is given with training programmes and standards of supervision. All of these aspects are approached in the spirit of the Congress declaration that the first priority and concern must be the health and safety of the miner.

Jan 1, 1974

By Rick Frechette, Bryan Ulrich

Representatives from several mining operations in three western states left their mines behind for a day in February to discuss with their peers the issue of water. The event was Knight Piésold and Co.’s Roundtable 2007, held in Elko, NV. It was third such event put on by the company. The issue this year was site-wide water considerations.

Jan 1, 2007

By Dunbar D. Scott

The development in the perfection of mine-surveying instruments has been by no means rapid, as it has depended somewhat on the details of construction borrowed from astronomical and geodetic theodolites, largely on the restrictions laid down by mining companies and the prejudices of mine managers themselves, but more than all on the methods used in conducting surveys and the importance attached thereto. Mine-surveying, in some form or other, has been practiced from the very earliest times; but it has never kept pace with the other branches of surveying, or even with the art of mining itself, and cannot be recognized as an exact science until shortly before the beginning of this century. The works of Hero of Alexandria, who lived in the second century B.C., are still extant, and contain descriptions of a rectangular sighting-instrument, which he invented and called a diopter. His improvement upon this simple construction, which possibly he devised for use in the Greek mines for rough leveling-purposes and for laying out any angle, must be considered, says Hübner," as the origin of the highly perfected theodolite of to-day. Whether this instrument came into general use during the first centuries of the Christian era, is not recorded; in fact, no writer undertakes to tell how mine-surveying was conducted until 1556, in which year Agricola expounds the principles of mining and metallurgy in his De Re Metallica, devoting the entire fifth chapter to the practice of mine-surveying (see Fig. 1). In mediæval times those who possessed any knowledge of engineering skill made strenuous effort to keep their art a secret, partly on account of the miners' proverbial conservatism and partly for their own personal aggrandizement, and were, in

Jan 1, 1899

By TSUYEE PEI

I FEEL greatly honored and appreciate this opportunity to be able to say a few words about that rather perplexing subject, silver. The constant decline in the price of this metal has now reached the stage where it is of much concern and the cause of serious discussion among the leading financiers, economists, and statesmen of the world. Further- more, it is significant that this subject is so important that almost every day one can read articles pertaining to it in the newspapers and trade publications. Being essentially a banker, and not an economist, I do not claim to be an authority on the silver question. These remarks are merely some of my observations in, regard to the many puzzles which-I came across in my recent studies of this very important question.

Jan 1, 1931

By Frederick T. Graybeal

Silver Bell is located about 56 km (35 miles) northwest of Tucson, AZ. It is a classic porphyry copper deposit containing enriched disseminated chalcocite ore in altered porphyritic rocks with chalcopyrite in adjacent skarn zones. The discovery of Silver Bell was an evolutionary process that occurred over a 75-year period. Recorded mining activity began about 1865 on Boot Hill east of El Tiro pit (see Fig. 1) where outcrops of altered limestones were found to contain 425 to 482 g (15 to 17 oz) Ag mixed with copper oxides. By 1874, the Young America Copper Co. was mining shallow occurrences of 30% Cu along the north side of the present Oxide pit. The ore was shipped by wagon to Yuma, AZ, and then by boat to San Francisco for smelting. By 1881, the district supported several mining companies, two small smelters, and was being favorably compared to Bisbee in local newspapers. Most of the ore mined in the period 1865-1903 came from pods of massive sulfide or their oxidized products which were distributed in an unpredictable fashion through a large skarn zone in Paleozoic limestone east of El Tiro pit. Ore grades varied from 5 to 10% Cu.

Jan 1, 1991

By S. M. Pickering, L. T. Gregg

Appraisal of industrial minerals beneath privately owned land requires a different approach and mindset from valuation of base and precious metals or energy minerals, and from valuation of government-owned mineral lands. First, is it the value of inground minerals or of mining rights that is being sought? Second, value to whom, the mining company, a potential investor, the mineral landowner, a lending institution, the property tax assessor, or a condemnor? Third, how should mineral value be apportioned between the land and mineral owner, and a mining company with limited years of lease-hold interest? These and many other questions must be addressed before a valuation method and Discount Rate are selected. For various reasons the Income Method is most often used, with Net Present Value calculations made for long term predicted mining income. Choice of an appropriate Discount Rate is critical.

Jan 1, 2000