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By John Olivera

El objetivo principal, es mejorar la preparación y el minado mecanizado de las Operaciones, de los resultados de minados de la variante del Sub Level Stoping, se genera el método AVOCA, una combinación con el Cut and Fill Stoping tradicional y en los avances el uso de detonadores electrónicos con el objetivo de realizar un método de segregación en los sub niveles (2.8m ancho x 3.8m altura) que se adapta al minado en Vetas Angostas, con una mejora que es el uso de Micro - Equipos Trackless (Equipos de bajo perfil menores a 2.0 m de ancho) en cada proceso de la operación unitaria. Con este método de minado y los equipos diseñados para labores angostas se mantiene y controla un límite máximo de abertura, en la preparación y en el minado.

Sep 30, 2022

By Edward Medina

El presente trabajo señala el método de minado "sublevel stoping" aplicado a través de la perforación de taladros largos ubicados cada 50 cm. en el yacimiento minero de San Rafael, Puno. Esta perforación acorta el tiempo de ejecución y el costo se reduce considerablemente en la preparación de la labor. Asimismo, la perforación radial minimiza la perturbación al macizo rocoso debido a que se realizan menos voladura en los alrededores, como también se tiene menos área expuesta a deformaciones. Finalmente, el uso de los equipos de última generación, permiten controlar mejor la desviación del taladro a mayor longitud, que en años anteriores fue uno de los principales limitantes.

Sep 13, 2001

By Paul Gauthier

Aujourd?hui, avec un faible prix de l?or sur le marché, les opérateurs miniers doivent revoir leur façon de faire. La méthode de minage «Eureka» permet de réduire les coûts de production et d?accélérer la mise en production des chantiers. Les principales étapes du cycle de minage et les problématiques associées à l?utilisation de cette méthode à la Mine Bousquet y sont décrites.

Oct 1, 2001

By José Vilca

La exploración cristaloquímica es una herramienta que permite descubrir mineralizaciones con estaño en lugares donde otros métodos no tuvieron éxito. En ese sentido, el presente texto describe la función de dicho método -en tanto identifica las zonas con ordenamientos atómicos específicos relacionados con la ubicación espacial de mineralizaciones de interés económico importantes. Asímismo cuantifica la concentración de los elementos químicos en la cristal-estructura de los minerales tales como óxidos, sulfuros y silicatos, y determina el grado de evolución cristalogenética de los minerales estudiados y su función a nivel molecular específica de cada uno de estos Estado Cristalo-Estructural ECE.

Oct 21, 2015

By José Cipriano Vilca Valdivia

El presente texto describe el método Crys-Explo o Exploración Cristaloquímica -en tanto descubre mineralizaciones de estaño en lugares donde otros métodos no tuvieron éxito. El procedimiento ayuda a identificar las zonas con ordenamiento atómicos específicos relacionados con la ubicación espacial de mineralizaciones de interés económico importantes. Asimismo cuantifica la concentración de los elementos químicos en la cristal estructurada de los minerales como óxidos, sulfuros y silicatos y determina el grado de evolución y su función a nivel molecular específica de cada uno de estos Estado Cristalo-Estructural (ECE).

May 1, 2017

By COURTNEY DE KALB

IRON ore is the cause of the present trouble in Morocco. At least three nations are interested in the outcome and private syndicates have been active. The iron deposits are found in that mountainous northern coast line known as the Rif. This is an uplift that has been cut through, by the northward drainage, representing an ancient land surface. Erosion has produced .a fiordlike coast, which circum- stance has aided contraband' traffic to the tribes dominated by Abd-el-Krim, the chief of the clan of the Beni Urriaguel, near the center of 'the north coast, opposite Alhucemas. The iron deposits are extensive in the territory of the Beni Urriaguel. They were "located," if such a term is permissible, many years ago. The first arrangements, through direct contracts with the tribal chieftains, have been reinforced by compliance with the subsequent code under the Spanish protectorate in 1914. Under those terms, the location had to be made through the Arbitral Commission sitting in Paris. These locations, or "denouncements," were made by the I-louse of Mannesmann, of Hamburg.

Jan 1, 1925

By S. A. Scott

Mintek developed the MinataurTM leach-solvent extraction-precipitation technology as a cost effective, easily operated alternative to conventional gold refining processes. The technology was first commercialized at the Harmony Gold Refinery in 1997 to produce 99.99 per cent gold product and has subsequently led to development of various value-addition steps including the casting of various investment bars, gold wire drawing and gold potassium cyanide powder production. In addition to refining gold to high purity, if an appreciable amount of silver is present in the feed material it is also refined to 99.99 per cent purity. The major advantage that the Minataur? technology has over other gold refining processes is the relatively low gold lock-up and reduced operating costs. The operating cost1as at April 2001 for the expanded Harmony refinery (24-ton per annum gold production) was approximately half that of conventional smelting and toll refining. The extractant employed for solvent extraction is relatively cheap and highly selective for gold, making the technology attractive in situations where significant quantities of platinum group metals or base metals are present.

Jan 1, 2004

By K. D. Watson

"THE Mindamar zinc-lead-copper mine, owned by Mindamar Metals Corporation Limited, is at Stirling in Richmond County, near the south-eastern shore of Cape Breton Island, Nova Scotia (Figure I). It is connected by several roads with the Canadian National railway at Sydney and St. Peters.The deposit is said to have been discovered around 1895 as an outcrop in the bed of Copper brook, but the details are obscure. Not until 1925, when it was optioned by American Cyanamid Company, was it developed underground. Between 1927 and 1938, the 1-nine was operated intermittently by The British Metal Corporation (Canada) Limited, and yielded approximately 200,000 tons of ore averaging about IO per cent zinc, 2 per cent lead, I per cent copper, and small quantities of silver and gold. In December 1950, Dome Exploration (Canada) Limited made an agreement with Mindamar Metaî Corporation Limited, which was exploring the old mine, to assume management and prepare the property for production. Production started in April 1952 with a new mill and a new four-compartment shaft, and between that time and the end of 1954 it has totalled 545,347 tons of ore averaging 5·89 per cent zinc, 1·35 per cent lead, 0·66 per cent copper, 0·032 oz. gold, and 2 151 oz. silver.The Mindamar orebodies are irregular lenses and large veins lying within a wide, almost vertical shear zone of remarkable persistency. The shear zone consists mainly of well-foliated sericite schist derived from siliceous siltstone, and it contains a vast amount of dolomite and magne-site of hydrothermal origin. Most of the ore is extremely fine-grained and some of the high-grade material has a conspicuous thinly layered structure. The metallic minerals, in order of decreasing abundance, are pyrite, sphalerite, chalcopyrite, galena, and tennantite; the gangue minerals, in the same order, are dolomite and magnesite, quartz, sericite, talc, chlorite, barite, albite, and alunite.The geological setting of the deposit is shown in Figure 2. Except along streams and lake shores, almost all of the bedrock is concealed by glacial drift. The group of rocks in which the deposit occurs consists principally of greywacke, siltstone, tuff, brecoia, and Javas, and has been correlated lithologically with the Bourinot group of Middle Cambrian age. A short distance west of the mine, these rocks are in contact along the Stirling fault with conglomerate, arkosic sandstone, and quartzite belonging to the Middle River group of Silurian or Devonian (?) age, which elsewhere in the area overlies the Bourinot group unconformably. The large bodies of granitic rocks in the region, and the large lenticular masses of diorite and quartz diorite associated with them, have been assigned by Weeks (5, pp. 68-69) to the Devonian."

Jan 1, 1949

By Jack A. McQuiston, Thomas A. Cross

Corrosion of equipment and machinery in the coal industry is usually the result of three main agents: acids, chlorides, and abrasion. Acids and chlorides are especially troublesome in coal preparation plants where soluble salts and sulfur in the coal produce a highly corrosive wash solution. Abrasion is common in all operations where coal is handled or conveyed. Together, the acid-chloride-abrasion combination results in some of the worst corrosive conditions found in any industry. The variety of equipment and structures in the coal industry calls for different corrosion control techniques. Table 1 lists the areas of concern for a number of items. Just as there is a wide variety of corrosion problems, there is a wide array of coating materials available. Tables 2 and 3 are selection charts to provide guidance in narrowing down the choices. Experience has shown that a limited number of coating systems work best on coal equipment and structures. These systems are described in Table 4. The good-better-best designation in the table refers to coating system longevity. Good indicates the least costly and shortest service life. In nearly all cases the lowest annualized cost can be achieved by using the coating system rated best, due to the avoidance of costly repaints and unnecessary downtime. The most expensive coating system, though, is worthless unless the coating system is properly applied. Field inspection to insure compliance with specifications is an important aspect, and is a service available from many coating suppliers. Even the best coating systems require periodic maintenance to achieve satisfactory results. Spot rusting from mechanical damage should be repaired annually to maximize the coatingsystem's results.

Jan 2, 1980

By T. M. Biddle

If an accident occurs at a mine, the mining company, its parent and affiliates, and its supervisory employees may face substantial -- and sometimes unexpected -- liabilities and costs. This presentation surveys the likely sources for post-accident exposure, including wrongful death and personal injury claims, mine closure/operational disruptions, and government civil and criminal actions against the company and its employees.

Jan 1, 1986

Early strategic mine planning includes decisions over the organisation of work and workforce accommodation. These decisions involve significant commitments that affect not only employee quality of life but also the impacts and relationships with existing local communities. Strategies for workforce accommodation are characteristically community-based (either as purpose-built company towns or integrated within existing local communities) or commuter (fly-in, fly-out) mine camps. The quality of accommodation underpins the fulfilment, morale and motivation of employees. This is not only relevant to productivity and safety, but also to recruitment and retention, particularly with the current onset of a significant human resources crisis. In the event that communities exist in proximity to a proposed mine then the accommodation strategy selected can influence the value-adding potential for the sustainable development of such communities. This early planning is particularly challenging where mine locations are isolated and/or face significant economic, social and political adversity. This paper draws upon a case study review of five large mining projects implemented in three South American countries, selected to cover a range of scenarios and accommodation strategies. The review aims to advance our understanding of the complexity of the underlying planning issues. Each scenario considered the prevailing environmental, social, economic and political situation, together with the adopted accommodation strategy. The case study review aimed to identify lessons learned and to make recommendations for advancing mineworkersÆ accommodation planning practice.

Jan 1, 2006

By S. A. Braley

Water is our most important natural resource, for without it there is no life. It is also the principal natural resource for all manufacturing processes, in particular for the development of power. For these reasons it is essential that water be protected and conserved, with the realization that its quality 18 as important as the water itself. A significant factor in the quality of ground water is the mining of coal -- that other main ingredient of Power. In the mining of coal it is necessary to disturb the geological strata overlying or adjacent to the coal seam. This procedure not only releases water from water-bearing strata or underground aquifers but also exposes other minerals which eventually become the source of pollution or deterioration of the released water as well as of the surface stream into which It is discharged It is then evident that in attempting to utilize one essential natural resource there is degradation of the quality of the other. Many selfishly assume that the principal function of a stream is fishing and recreation, but the real function is the support of industry and agriculture upon which civilization is dependent.

Jan 1, 1959

By Bruce K. Cantrell, Jon C. Volkwein

Exposure to mineral aerosol is an occupational health hazard in mining and mineral processing industries because of the risk of developing pneumoconiosis. Agricola (1556) described this hazard for metal mining in Carpathia. He described shortness of breath and consumption, conditions that are now associated with asthma and emphysema. By the end of the nineteenth century, several respiratory diseases were known to affect miners, including silicosis and coal workers' pneumoconiosis (Fletcher, 1948; Seaton et al., 1981). For example, silicosis, not tuberculosis, was clearly recognized as the hazard in the Vermont granite quarries and stone-cutting sheds (McFarland, 1927). The Gauly Bridge Tunnel disaster in the mid-1930s caused the deaths of an estimated 700 workers by acute silicosis and focused the nation's attention on this disease (Cherniack, 1986). By the mid-twentieth century, it was clear that risk of simple pneumoconiosis is associated with a miner's cumulative exposure to mine aerosol in the respirable size range and that prevention lies in reducing that exposure through regulation (Seaton, 1986). In the United States, regulation of mine worker exposure to airborne mine dust is the responsibility of the Mine Safety and Health Administration (MSHA) in the U.S. Department of Labor. The key legislation relating to improved mine worker health was the Federal Coal Mine Health and Safety Act, enacted in 1969 (U.S. Congress, 1969) and subsequently amended as the Federal Mine Safety and Health Act of 1977 (U.S. Congress, 1977). MSHA receives technical assistance from the National Institute for Occupational Safety and Health (NIOSH). NIOSH also provides recommended exposure limits (RELs) for contaminants to MSHA. MSHA's regulation of mines includes the establishment of a dust standard administratively based on the these RELs. Some mine operators must submit a dust control plan designed to meet the dust standard. Periodic mine inspections determine if mines are com- plying with both the dust standard and the dust control plans (MSHA, 1991). The most common dust measurements are those for respirable dust (according to the definition given in Fig. 26-7), that is, the fraction of aerosol particles able to reach the gas exchange region of the lungs. The other health-related size fractions (inhalable and thoracic-see Fig. 25-1, and "total" dust) are also occasionally measured. A "total" dust measurement is defined by the common practice of the last 30 years or so, using 25 mm or 37mm plastic cassettes (e.g., from PAL, MIL, SKC ). The types of mines have been categorized

By Liu Cheng-si

Variable airway is controllable, which is an important discovery in ventilation research in recent years. For this reason, conventional calculating methods are no longer suitable to solve this problem. I used Mayeda-Seshu and Newton methods to solve the above problem before, they have been proved feasible. However, it is troublesome and difficult to apply to operation with a large amount of calculations. In this paper combination theory and simplified formula are used in determine all control plans and its parameters. This new method with less calculation is easy to understand and master, so it is more important in research and application.

Jan 1, 1997

To monitor the quantity and quality of air in underground mines to assure safe working conditions. Approach Several mine air monitoring systems, consisting of sensing stations in the return airways and control stations on the surface, have been Installed and tested. How It Works Sensor stations are located at strategic places in the underground mine. At each station, the sensors measure air velocity, air temperature, methane concentration, and carbon monoxide concentration. In one system, differential air pressure between intake air and return air, is also measured. Output voltages of the sensors are converted to digital signals at the sensor stat ion; these signals are multiplexed so that data from all sensors can be trans-phone wire to a central station. There the data are displayed and alarms are triggered when the sensed values exceed (or in the case of air velocity, fall below) a preset value. In addition to receiving data automatically, the central station can poll individual sensors at any time.

Jan 1, 1978

By W. L., Yerkes

AN interesting study of the application of air-, conditioning to the problem of mine ventilation and cooling can be found on the Witwatersrand in South Africa. Here there are a large number of deep mines in a relatively small area. Due to the nature of the reef, many mines are working at a depth of 6000 ft. and some have gone down to 8000 and 9000 ft. below the surface. At such depths, even in a country geologically as old as Africa, the virgin rock temperature approaches 110°F. The flow of heat from the- rock to the ventilation air is tremendous though the shaft or drift may have been open to ventilation for some years. In addition, there is the heat produced by machinery, lights, and men at work and the heat of adiabatic compression of air introduced into the mine. The difference in atmosphere pressure between the collar of a shaft and a level 6000 ft. below is nearly 3lb. per sq. in., resulting in an increase in heat content of nearly four B.T.U. per pound of air delivered to the mine at surface. Further the exclusive use of wet mining to reduce the incidence of miner?s phthisis increases the latent- heat content of the air.

Jan 1, 1941

By J. L. Bowlby

OWING to the pressure of routine analyses at the laboratory during the past year, work of an investigational nature on water problems has been greatly curtailed. Favourable reports by the boiler inspectors indicate that the operators are giving satisfactory attention to feed-water treatment at the several . power plants. Some of the operators prefer lime and soda, others the phosphate and soda treatment. Springhill is still on the same commercial treatment as they were using last year, and satisfactory results are being obtained. This individual preference for a particular treatment, although it may be different for feed waters of similar nature, indicates that so long as proper conditions of alkalinity and concentration are maintained within the boiler, it is immaterial what chemicals are used in the treatment. This statement refers, of course, to the low-pressure boilers. In high-pressure boilers, a treatment such as lime and soda cannot be satisfactorily employed, on account of the precipitated calcium carbonate unduly increasing the amount of suspended matter. Only one case of impending trouble was reported during the year. That was at Seaboard, shortly after the new unit was placed in operation. Dissolved oxygen, considerably in excess of the permissible 0.030 cubic centimeters per liter, was detected at various points on the feed line. It was suspected that a de-aerating heater was being operated at too low a temperature, and chemical tests, made before and after the necessary adjustments, proved that this was the source of the trouble. While it has been impossible to give mine waters the attention they require, progress can be reported in the work carried out by the Mechanical Department. Past investigation of the action of mine water on various acid-resisting alloys is now bearing fruit, and it can safely be said that repair work on mine pumps has been reduced by nearly one-half.

Jan 1, 1938

By Leons Kovisars

Introduction Labor is the major cost element for most mining operations. Labor costs are continually increasing, both in nominal and constant terms. This is true in developed as well as less developed countries. There are two ways to control unit labor costs - labor costs per ton of ore mined. Replace labor with capital (increased mechanization) or improve productivity (reduce the labor force). Every miner is aware of specific inefficiencies at his or her particular operation. But the miner has no comparative measurement standards. So it is difficult to know whether these inefficiencies are major or minor. The miner may also be unaware of large-scale inefficiencies because ongoing labor practices may have caused management complacency. Met Research studied mining labor productivity. The firm collected pilot data by sending direct-mail questionnaires to 320 nonferrous mining operations around the world. The response rate was 27%, of which 78 operations provided full data on production and employment.

Jan 11, 1983

By H. Kenyon Burch

INTRODUCTION THE Inspiration Consolidated Copper Co.'s plant at Miami, Ariz., was designed and built to make possible the profitable working of a low-grade, finely disseminated copper deposit containing 100,000,000 tons of ore averaging 1.64 per cent. in copper. From the-beginning it was evident that the-plant could not, be kept integral but that a break would have to be made somewhere in the flow-sheet, removing at least the concentrator to a site more suitable than any available near the mine. It was finally decided, after considering numerous arrangements, to do the coarse crushing at the mine, to store the crushed ore in a bin from which it could be loaded into railroad cars and to haul it to the concentrator, an excellent site for which was available about 1 ¾ miles from the mine. The original intention was to equip a plant to treat 7,500 tons of ore per clay, but through the acquisition and proving up of additional ore reserves, the introduction of the Ohio caving system, and the excellent results obtained in the test mill (which made it possible to treat a lower-grade ore than had been thought possible) it was evident that a plant of much greater capacity should be supplied. It was, therefore, decided to treat approximately 15,000 tons of ore per day, the duties of the four main divisions to be as follows:

Jan 9, 1916

By W. J. Kuit

"Complex facilities which provide for the collection, management and treatment of effluents emanating from the Sullivan mine and concentrator tailings were made operational in October 1979. Key features of the system are the use of upgraded tailings ponds for the storage of up to 800 million litres of metals-contaminated effluents, a treatment plant employing lime in a high-density sludge process and a sludge-impoundment facility designed for maximum long-term environmental safety. The completed works are capable of satisfying a difficult range of operating requirements imposed by highly variable weather conditions, drainage flows and soluble metals loadings. Final capital expenditures for the project approached $10 million and annual operating costs are about $0.8 million.This paper discusses the Kimberley effluents treatment project and the major considerations in its development. The treatment process, major plant equipment and initial operating experience are also described.IntroductionCominco Ltd. has worked the Sullivan orebody at Kimberley, B.C. since 1909 and has operated a concentrator some 5 km distant from the mine since 1923. Over the last 70 years, in excess of 120million tonnes of ore have been mined, and production continues at an average rate of 6,500 tonnes per day. It is a well-known fact that the contribution of this operation to Canada's mining industry and, in particular, Cominco's development has been significant. However, this success has not been without some undesirable side effects.Unfortunately, the Sullivan is one of only a few major Western Canadian orebodies which may be classed as ""acidic"" in nature. That is, the primary economic minerals, galena and marrnatite, are enclosed in a siliceous host rock with abundant pyrrhotite, but with little or no accompanying alkaline gangue minerals such as calcite and dolomite. The unavoidable consequence of mining such an ore is that contact with air and water generates an acid mine drainage containing various soluble metals orginally present as minerals.This problem also arises in the concentrator's tailings ponds, which, in the case of the Sullivan, are two separate impoundments of different materials. The 1,100 tonnesl day of ""iron"" tailings are primarily pyrrhotite which is surplus to the requirements of a separate operation that produces sulphuric acid as an intermediate to phosphate fertilizers. Inert gangue minerals with only a minor sulphide content are the main constituents of the 1,200 tonnes/ day of siliceous tailings. Corresponding to the relative proportion of sulphides in the solids, the decant from the iron tailings is substantially more contaminated than that from the siliceous pond."

Jan 1, 1980