Search Documents

By John Wiebmer

Six industry trends will have significant effect on the way mining equipment is designed and supported in the years ahead: 1. MINING IS MIGRATING TO LESSER DEVELOPED PARTS OF THE WORLD The global recession of the early 1980's drove down commodity prices and intensified cost competition. This caused a fairly dramatic trend in mining away from higher cost operations in developed countries to richer, lower cost deposits in developing countries. Miners operating in lesser developed parts of the world will place higher value on rugged, durable designs that can live in more difficult and sometimes abusive conditions. They need engines and power train systems that are more tolerant of a wide variation in fuel quality and oil specifications. They'll require machines that are simpler to operate, simpler to maintain, simpler to troubleshoot and simpler to repair. And they'll require creative means of support in getting technical information, parts and components to remote operational sites. Mining equipment in the future will be more durable and simple than it is today, and product support will grow in importance as purchasing criterion. 2. THE MINING INDUSTRY IS CONSOLIDATING An intense amount of corporate acquisition and industry consolidation activity is occurring, to the point that today just 50 mining companies account for 55% of the western world non-fuel mineral production. Consolidation will continue, leading in the future to an industry structure weighted heavily toward a few key global mining houses.

Jan 1, 1993

By S. Guo

In this paper, a model for the resin anchor bolt system is developed in which the smooth bar is modeled by using one-dimensional truss elements and the resin annulus is modeled by using axisymmetric elements. These two submodels are combined together and then incorporated into the' existing computer code ROOFBOLT. After this development, all of the components in the resin anchor bolt system including smooth bar, bearing plate and resin annulus can be correctly modeled.

Jan 1, 1995

By Francisco Sierra García

El presente texto señala la evolución del proceso de la flotación desde 1930 hasta la década del 80. La flotación por espumas en el proceso de separación de los minerales es importante - en tanto aparecen las primeras celdas de flotación rotativas. Las evoluciones se basan en la forma, tamaño, tipo de materiales y adición del aire y es necesario el uso de maquinarias y técnicas por la calidad y precio.

Sep 1, 1988

By Evan Jamieson

The conditions under which various iron(III) oxy-hydroxides phases precipitate from iron(III) chloride and sulfate solutions at ambient temperatures (<60°C) are reviewed. Many of these precipitates are slow settling and gelatinous but ultimately transform into other more stable or crystalline phases. The phase that forms depends upon the rate of precipitation and pH. A comparison has been made of the iron(III) oxides formed upon the neutralisation of various iron(III) solutions with caustic, slaked lime or slaked magnesia which provide different rates of neutralisation and slowly dissolving solids with localised high pH. Mössbauer spectra of ferrihydrites precipitated under these different conditions are compared and interpreted. Particular attention is paid to the settling rate and settled volume which is likely to relate to industrial thickener and filter performance. It is shown that in pure chloride solutions, poorly settling ferrihydrite is usually produced at 20oC regardless of the choice of base. However in sulfate solutions fast settling precipitates are produced using lime and magnesia but not with caustic. In mixed chloride/sulfate solutions, optimum settling rates occur when the molar ratio of [SO4]2to Fe3+ is about 1:1 and when the sulfate concentration is <0.20 M. It is proposed that ?dense amorphous basic iron sulfate? or well-ordered ferrihydrite is formed on slowly dissolving lime or magnesia surfaces. Implications for industrial liquors are considered.

Jan 1, 2003

By James Terry Duce

The symposium on production for the year 1940 contains few papers on the foreign situation. It is probable that the foreign part of next year&apos;s symposium will be even shorter. This is due to rigid censorship in various countries, as the question of the volume of petroleum supplies has become one of great strategic importance. This is even more true than in the last war, owing to greater mechanization of armies. &apos;It has always been the policy of officers in charge of the symposium to refrain from publishing information that might possibly injure national or private interests. At the close of the war we hope again to publish full and accurate records of production abroad. Excerpts from Circular to Authors In order to facilitate interpretation of the data in this chapter, we print the following excerpts from the Circular to Authors. The field is the unit in this tabulation. In cases of fields extending across State boundaries, such as Rodessa, it is suggested that each State author treat the section of the field in his State as a unit, and by a footnote indicate that the field extends into an adjacent State. Each space in Table I may represent one of four possibilities; either it is not applicable to the particular field, or the proper entry is not determinable, or the proper entry may be determinable but is not determinable from data available to the author, or the proper entry is determinable. When spaces are not applicable, leave blank; in spaces where the proper entries are determinable but not de-terminable frod data available to the author, please inserty; in spaces where the proper entries are determinable by the author, make such entries. y implies a hope that in some future year a definite figure will be available. The entry of a zero is a positive declaration, and an important declaration where it is in order. Inability to determine precisely the correct entry for a particular space should not lead the author to insert merely y. Contributions of great value may be made by the author in many cases where entries are not subject to precise determination. In sucli cases the author should use his good judgment and make the best entry possible under the circumstances. For many spaces the correct entries represent the opinion of the author (for example, "Area Proved&apos;) and in such cases the entry need not be hedged to such extent as when the quantities are definite yet can be ascertained only approximately by the author. In cases under definite headings but where figures are only approximate, the author may use x. It is thought that the nearest whole numbers are sufficiently accurate for our purposes except as to percentage of sulphur in oil. If an author desires to report any other figures to tenths, he may do so. The quantity of gas produced should include, where possible, gas sold or otherwise marketed, and gas blown into the air, burned as flares or otherwise wasted. Segregation of these figures would be interesting if the authors can make such segregation. In any event, the figures should represent as nearly as possible the total quantity of gas removed from the reservoir. Under the columns on "Depth," the average depth to the top of the productive zones and to the bottom of the productive wells, when

Jan 1, 1941

By Adrian E. Scheidegger

"AbstractThe possibilities of deriving pertinent information about fractures in an oil pay from data obtained by core analysis are investigated. It is shown that it is possible to obtain an estimate of the fractured area per unit volume of the pay, and that the size of the fractures can be estimated if their shape is known. A suggestion of a routine procedure for the analysis of fractures is given.1.-IntroductionMany oil fields are producing essentially from cracks or fractures. Where this is the case, it is important to be able to obtain a knowledge of the size and distribution of those fractures in the oil pay. This knowledge has to be derived from the analysis of cores taken from the fields, as it is generally impossible to follow a fracture through the pay by direct means. The necessity of using statistical methods to extrapolate the meagre information obtained from the cores of the wells is therefore indicated.It is known that the fractures are much bigger than the diameter of the cores; thus, if they strike a core, the latter will generally fall into two pieces. The angle of the fracture with the vertical can be measured and, if oriented cores are taken, the exact position of the surface element representing the intersection of the fracture with the drill stem can be determined. Sometimes the edge of a fracture can be seen in a core. The number of •Cores that show such an edge can be noted. Of course, one has to be careful to distinguish between original fractures in the pay and fractures in the core caused by drilling operations. Only the former are relevant."

Jan 1, 1955

By H. G. Papacek

The Fabrica Mine of the Brazilian iron ore company Ferteco mines on an extremely inhomogenous ore deposit. A large amount of the crude ore consists of fines minus 100 micron which cannot be sold without further treatment because of its chemical and physical properties. In order to make full use of the mined crude ore an expansion program has been realized which incorporates among others a concentrator to produce classified blast furnace ore , sinter feed and pellet feed. The pellet feed is converted in a 2.5 million tons per year Lurgi Dravo plant into high grade pellets. The paper discusses the selection of the concentration process, the pelletizing process and describes the experiences with the operation plant during the startup and the first years of operation.

Jan 1, 1979

By Ronald Díaz

"Cerro Corona es un yacimiento porfiritico tipo stockwork con diferentes unidades geometalurgicas, las cuales son alteraciones producidas por una extensa familia de fallas geológicas que determinan un tipo especial demineralización. En ese sentido, a medida que la mina se va profundizando, la roca encajonante será menos alterada, así como se obtendrá una mayor dureza del mineral y los problemas asociados con el menor tonelaje de procesamiento. Por ello, el presente texto señala la optimización del procesamiento de minerales de bajo contenido de arcillas y alta dureza, así como la disminución de la malla de voladura, el incremento del factor de carga, Blending adecuado de mineral duro, la disminución del set de la chancadora, la instalación de cañones de aire en los chutes de transferencia, una mayor adición de bolas, los cambios en los diseños de linea, el control de desgaste de hidrociclones, sintonización de la lógica de control y el control supervisor del molino SAG, etc."

Sep 21, 2013

By R. Negrón

El presente trabajo describe la aplicación del proceso de lixiviación-cementización utilizado en la mina de Cerro de Pasco y en otros yacimientos de características similares. La aplicación tecnológica de la lixiviación subterránea data desde el año 1935, mientras que la lixiviación de las pilas del mineral en superficie y el proceso de cementación fueron implementados con ayuda de tecnologías análogas aplicadas en otras minas del mundo. En este sentido, si la particularidad de la lixiviación subterránea opera en áreas de explotación antigua donde las condiciones ambientales y de trabajo son bastante difíciles, impidiendo las operaciones normales que exige dicho procedimiento; el método de lixiviación-cementación en Cerro de Pasco permite recuperar una cantidad considerable de minerales de cobre dejados en el sub-suelo, de forma que se puede recuperar el contenido de cobre del mineral de pirita depositadas en pilas producto del desbroce del tajo abierto.

Nov 20, 1978

There are multiple stages in a mining operation that a mining engineer has to draw polygons to be used as operation guidelines. These polygons are drawn by hand and based on engineer?s experience. However, having automatic procedures for forming the shapes can increase the quality and decrease the efforts required. These shapes need to be homogenous in grades and rock types so that the quality and dilution of material sent to the plant can be estimated with the good approximation. In this paper, a clustering algorithm with shape control is introduced which can provide reasonable guidelines for all the aforementioned shapes by manipulating its parameters. At the end, implementations of the algorithm on a small part of a gold deposit with different mining strategies is presented and evaluated based on homogeneity of grade, rock types and determined destinations as well as the shape.

Feb 27, 2013

By Y. S. Roditis

Traditionally, open pit optimization has been used to produce a single outline which can guide the pit design. This paper describes how a series of optimum nested pits are utilized to: a. produce different mining sequences and to help in mine planning and phase design; b. evaluate different metallurgical processes, production scenarios and equipment size; c. investigate the sensitivity of a project to prices, recoveries, production rates, costs, ultimate pit slopes etc.

Jan 1, 1993

By P G. Gaylard

The minerals Industry carries out over US$ 2 billion of R&D annually. The R&D is performed at three levels ? in house research facilities; on a one-on-one basis with a research provider; as syndicated (collaborative) research. The key to a successful R&D programme is project selection. It is suggested that at this time of ?bounty? for the minerals industry the research portfolio should contain some ?blue sky? but potentially long term significantly beneficial projects. This said, the projects should align the technical concepts with the business imperatives. AMIRA has found the ?Road Map? concept has assisted in defining areas for R&D. Examples of this methodology using a Copper Road Map developed by AMIRA for the copper producers operating in South America is presented. The benefits derived from syndicated research are also discussed.

Jan 1, 2007

By M. F. Bucek

This report summarizes the activities performed and the results achieved during a two-phased investigation of the technical and economic feasibility of disposing of coal mine refuse underground in active mines, Three coal regions in the United States that are most severely affected by coal refuse disposal problems are identified: southwestern Pennsylvania, southern West Virginia, southwestern West Virginia and eastern Kentucky. For each region, a conceptual mine model is presented that describes the geologic conditions, mining methods, and environmental circumstances typical of that region. The model mine that was prepared for the Kanawha Region in Southwestern West Virginia and eastern Kentucky was selected as the basis for developing alternative conceptual designs of underground disposal systems in the second phase of this investigation. Procedures used in selecting the regions and in modeling typical mines are described in Part I of the report. Part II of the report describes existing methods for stowing refuse underground, presents three alternative conceptual designs of stowing system that would be appropriate for the model mine postulated in the first phase of the study, discusses technical characteristics and environmental effects relative to the various systems, and evaluates the technical and economic feasibility of the three alternative disposal system designs. Comparisons costs among systems and with costs or surface disposal are presented.

Jan 1, 1980

By S. Masambi, S. M. Bradshaw, C. Dorfling

The presence of iron in base metal leach solutions complicates nickel and copper recovery processes. Leach solutions are commonly purified by precipitating iron as hematite, jarosite or goethite. Fast oxidation of ferrous to ferric is an important step to remove iron by precipitation at low pH values. This study reviews the ferrous oxidation mechanism and reaction rates in chloride media using molecular oxygen. This work contributes to the development of a better understanding of iron precipitation processing steps, which continues to be an important matter in hydrometallurgy. The specific objectives were to investigate (1) the effect of key process variables (acid concentration, copper concentration, and temperature) on the rate and extent of ferrous oxidation by dissolved oxygen and (2) the oxidation mechanism by varying chloride and hydrogen ion concentrations separately. Batch oxidation tests were performed using synthetic chloride solutions containing 45 g/L Fe and 3 g/L Ni at 50 and 80°C, dissolved Cu concentrations (0.3 to 3 g/L) and HCl concentrations (2 to 4.6 M). Regression analysis indicated that the significance of the effect of different variables on the extent of oxidation achieved after five hours decreased in the following order: HCl concentration > Cu concentration > temperature. Increasing the HCl concentration from 4 M to 4.6 M caused the degree of oxidation achieved after two hours to increase from 58.3% to 98.1%. The catalytic effect of dissolved copper on ferrous oxidation was more significant at low acid concentrations. Experimental data suggest that rapid oxidation of ferrous is possible at high HCl concentrations for two main reasons. First, the formation of ferrous chloride complexes allows ferrous oxidation to proceed without the formation of superoxide as an intermediate product (the rate limiting step in dilute acid solutions). Second, the formation of ferric chloride complexes stabilises the oxidation product.

Jan 1, 2016

By Michael Harley, E. Guy Charleworth

"Bedding-parallel thrust-hosted gold veins are developed in the Sabie-Pilgrim&apos;s Rest goldfield, eastern Transvaal, South Africa. The reefs display a complex history characterized by temporally and spatially overlapping events of similar mineralization and deformation. Recognition of the episodic reactivation of these low angle (5° to 10°) thrust faults implicates high fluid pressures (equalling or exceeding lithostatic pressures). Geochemical constraints limit the amount of fluid-rock interaction and the occurrence of transgressive mineralization within the Archaean granitoid basement suggests that the high pressure fluids originated at depth beneath the Transvaal Basin.Similarities exist between gold deposits of Sabie-Pilgrim&apos;s Rest and Telfer, Western Australia as well as Passagem de Mariana, Minas Gerais, Brazil. All deposits are sub-parallel to the enclosing bedding which is shallowly inclined. Furthermore, they are also hosted by contractional deformational structures and are clearly epigenetic in origin."

Jan 1, 1994

The Upper Waimangaroa mining permit is part of the Buller Coalfield and lies on the eastern side of the Stockton-Denniston Plateau. The mining permit area is estimated to contain a total in-ground coal resource of 58 million tonnes, contained within 13 separate coal resource .blocks. The coal is Bituminous High Volatile B rank with export potential as semi soft coking or thermal coal. The Northern Opencast mine is the first mine proposed for Upper Waimangaroa and consists of the three resource blocks at the northern end of the permit area. The highwall of the mine will cut into the Mt William Range resulting in overburden cover of up to 150 metres in some areas. The ability to rehabilitate the area after mining was a major consideration in the design of the mine. The Northern Opencast area has been geologically mapped, extensively drilled and effectively modelled using Vulcan software. Three distinct coal seams are present and the mineable in situ resource is estimated at 8.7 million tonnes of which approximately 7.1 million tonnes is likely to be recoverable. It is proposed that this resource will be mined using opencast methods and the void will be backfilled with overburden. The life of the mine is at this stage estimated at 19 years based on an annual production of 500,000 tonnes at 1.8% sulphur and the Upper Waimangaroacoal will be blended with low sulphur coal from the Greymouth Coalfield to meet export specifications. The Northern Opencast area contains a range of native flora and fauna and physical features which make it an environmentally significant area. Mining will totally modify the area, thus an effective rehabilitation scheme is an integral part of the mine plan. Various rehabilitation methods will be used, and wherever possible, the backfilled areas will be rehabilitated so as to resemble the original area as closely as possible.

Jan 1, 1998

By Bruce Watzman

"Few issues are more important to the National Mining Association (NMA), the U.S. mining industry and NMA’s MINExpo International 2016 exhibitors than safety.Global mining safety and health is a journey necessitating continuous improvement, collaboration and innovation on the part of both mining operators and their suppliers.MINExpo 2016, which takes place Sept. 26- 28, 2016, in Las Vegas, provides attendees with the opportunity to view technologies to help refine management of mining safety and health, utilizing NMA’s CORESafety system. CORESafety ‘One of the best’Launched by NMA in 2011 and moving forward ever since, CORESafety is driving continuous improvement in safety and health performance among participating industry companies by shifting from a command-andcontrol regulatory approach to a risk-based systems approach built on the Plan-Do-Check-Act model (Fig. 1).Considered an exemplary safety and health management system, NMA’s CORESafety system helps mining operators change their approach to safety and health management by enhancing the safety and health culture throughout their organizations. Although it is challenging to consistently and completely control all the factors and variables occurring in daily mining operations, experience has shown that applying systematic controls to as many variables as possible is the most successful approach for improvement in mining safety and health.When embarking upon the development of the CORESafety framework, NMA’s leadership set an ambitious goal to eliminate fatalities and reduce the injury rate 50 percent in five years, or the “0-50-5” goal. While the goal has not been met yet, the steady progress has been extraordinary with fatalities among participating companies dropping 45 percent during the period 2011-2015 (Fig. 2). Data also demonstrate that, as participating companies increase their level of implementation, total injury rates have also declined (Fig. 3).In a September 2015 interview with NMA, Penn State University mining engineering Professor Jeffrey Kohler praised CORESafety as “an inspired and timely program that brings together key elements to achieve safety and health goals.”"

Sep 1, 2016

By Basil B. Zavoico

The symposium on production for the year 1942 contains no papers on the foreign situation except those on Argentina and Mexico. It has always been the policy of officers in charge of the symposium to refrain from publishing information that might possibly injure national or private interests. At the close of the war we hope again to publish full and accurate records of production abroad. Excerpts From Circular to Authors In order to facilitate interpretation of the data in this chapter, we print the following excerpts from the Circular to Authors. The field is the unit in this tabulation. In cases of fields extending across State boundaries, such as Rodessa, it is suggested that each State author treat the section of the field in his State as a unit, and by a footnote indicate that the field extends into an adjacent State. Each space in Table I may represent one of four possibilities; either it is not applicable to the particular field, or the proper entry is not determinable, or the proper entry may be determinable but is not determinable from data available to the author, or the proper entry is determinable. When spaces are not applicable, leave blank; in spaces where the proper entries are determinable but not determinable from data available to the author, please insert y; in spaces where the proper entries are determinable by the author, make such entries. y implies a Rope that in some future year a definite figure will be available. The entry of a zero is a positive declaration, and it is an important declaration where it is in order. Inability to determine precisely the correct entry for a particular space should not lead the author to insert merely y. Contributions of great value may be made by the author in many cases where entries are not subject to precise determination. In such cases the author should use his good judgment and make the best entry possible under the circumstances. For many spaces the correct entries represent the opinion of the author (for example, "Area Proved") and in such cases the entry need not be hedged to such extent as when the quantities are definite yet can be ascertained only approximately by the author. In cases under definite headings but where figures are only approximate, the author may use x. It is thought that the nearest whole numbers are sufficiently accurate for our purposes except as to percentage of sulphur in oil. If an author desires to report any other figures to tenths, he may do so. The quantity of gas produced should include, where possible, gas sold or otherwise marketed, and gas blown into the air, burned as flares or otherwise wasted. Segregation of these figures would be interesting if the authors can make such segregation. In any event, the figures should represent as nearly as possible the total quantity of gas removed from the reservoir. Under the columns on "Depth," the average depth to the top of the productive zones and to the bottom of the productive wells, when subtracted, should give the approximate thickness of the productive zone. For fields where this is not true because of unusually high dip or for some other reasons, it is suggested that the authors indicate in their text the approximate average thickness of the productive zone.

Jan 1, 1943

By T. S. Bomar, C. J. Wood

Heavy media cyclones (HMCs) are efficient, high-tonnage devices suitable for upgrading run-of-mine coal in the 50 to 0.5 mm size range. Unfortunately, industrial HMC circuits are often not optimized due to problems such as incorrect operating pressures, poor feed distribution, excessive media contamination, mismatched components, and improper density control. To avoid these problems, operating guidelines have been provided in this article that are useful for optimizing the performance of HMC circuits. The validity of these guidelines has been assessed by means of density tracer tests carried out at several coal preparation plants.

Jan 1, 2002

By A. Sutherland Brown

"The Red Rose Mine is in the Rocher Deboule Range, 8 miles south of Hazelton. The mill camp (elevation 4,000 feet) is on Red Rose Creek, 11 miles by road from Skeena Crossing. The mine camp is one mile northeast and 1,600 feet above the mill camp on a spur of Red Rose Peak.The Red Rose mine was described in the Jubilee Volume, Structural Geology of Canadian Ore Deposits (Davis, pp. 129-131), but regional geology and mine development have progressed to a stage at which a more complete description is possible.The property was first located in 1912, and for the next 7 years was prospected actively for gold and copper on the southern extension of the Red Rose shear. Scheelite was first discovered in the vein in the northern part of the shear in 1923. The Consolidated Mining and Smelting Company of Canada, Limited optioned the property in 1939, and after a drilling program in 1940 the present mine development was initiated in the vein in the northern part of the shear. A 75-ton-per-day mill started operating early in 1942 and continued until 1943. The property was inactive until 195 l, when Western Tungsten Copper Mines Limited leased the property from The Consolidated Mining and Smelting Company of Canada, Limited. A mill, which later was enlarged to 140 tons per day, started operations at the end of 1951. The mine and mill were closed in December, 1954.The mine has twelve levels and sub1evels, and most of the workings are in the plane of the vein (see Figure 2a). The level interval is not constant, but between the lower four levels is 87 feet (100 feet in the plane of the vein). Access is provided by four adits; the 800 (elevation 5,659 feet), 600 (5,920 feet), 300 (6, 133 feet) and 200 levels (6,237 feet). The 600 level is the main haulage, and from it the ore is transported to the mill by aerial tram. From this level an inclined shaft extends in the vein to the lowest level (I, 100)."

Jan 1, 1949