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By Christopher C. Woomer

Cyprus Shoshone Mine uses the longwall method to extract a deep, thick, pitching coal seam in the Hanna Basin of South Central Wyoming. The immediate, and main roof rock consists of weak, thinly-bedded, silty mudstones with weak, interbedded fine-to medium-grained sandstone. Tailgate ground control has been a critical factor impacting productivity at the mine. A gateroad condition mapping program for the 11 left longwall gateroads indicated potentially severe ground control problems for the tailgate. It was predicted that the existing, secondary support pattern of wood cribs would not provide adequate support capacity. As predicted, severe deterioration of the tailgate occurred in the form of a roof cutter, sloughing ribs, and failing wood cribs. Productivity was affected and additional support was required. Shoshone personnel evaluated several options for providing the additional support needed in the tailgate. The additional support system and placement method had to satisfy several requirements with respect to access, materials handling, placement method, set-up time and support capacity. Approximately 6,000-ft. of deteriorating tailgate had to be supported. The initial wood crib support system left a 6-ft. walkway for access and construction of the additional support. This access was further reduced as the roof loaded the wood cribs. This eliminated the possibility of mechanized material handling to the construction locations. All materials would have to be transported by hand. The additional support system had to be placed quickly to stay ahead of, and keep pace with, the required longwall advance rate. It had to incorporate the existing wood cribs and provide at least 500 tons of extra support capacity. And most critically, the system could not affect longwall ventilation. Longwall coordinators and engineers made the decision to use a low density, pumpable cement known to the industry as TeksealTM, to provide the system required. A 200 psi ultimate strength mix was decided on to provide the required load capacity. The existing cribs were formed with 1-in. by 6-in. boards and brattice cloth to provide the containment. To overcome the access limitations, three boreholes were drilled from the surface to the tailgate on 2,000-ft centers. A mobile pumping station was established on the surface and the TeksealTM was pumped 900-ft. down the boreholes through a 1.5-in. steel pipe, then as much as 1,800- ft. along the tailgate entry through 1.25-in. miner spray hose. The materials required for the TeksealTM supports could all be carried into the construction locations by hand. As a direct result of incorporating relatively new methods of pumping high yield, low density, cementitious grouts, the Shoshone Mine reduced downtime due to tailgate ground control problems by approximately 70% in comparison with previous Longwall panels. The longwall set three monthly production records while mining the 11 left longwall under the deepest cover, steepest pitch, and most extreme ground control conditions ever encountered at the mine.

Jan 1, 1995

By R. E. Collom

The commercial development of petroleum and natural gas fields has reached its present status within 60 years and is still considered by some operators to be "100 per cent wildcatting." 1 A tendency to drill for gusher production, the production that yields big returns in spite of any mechanical defects in drilling methods, has frequently caused drillers to pass by oil-bearing strata of comparatively small yield and actually to overlook rich oil zones in proved fields; in addition, whole fields have been ruined by water because development methods were never carried beyond a hole-in-the-ground stage.2 Unfortunately, the petroleum industry has no mine dumps or tail. ing piles as at metal mines to yield fortunes through later and bette!' methods of treatment. The wasted oil and gas are gone, as are the time, money, and effort wasted in ill-advised or haphazard drilling. Probably as production costs increase less oil will be wasted, but the need to develop and produce from sands of low yield will become more urgent with the increase in consumption of oil and the decrease in supply. Hundreds of wells are producing steadily as the result of months and perhaps years of careful prospecting and of tests during drilling. The Bureau of Mines has studied the testing and drilling methods used at such wells, and presents in this paper a criticism of these methods and suggestions on future work. The term pr08- pecting here means correct identification and measurement of strata as they are exposed by the drill. The term testing means the determination of the kind and amount of fluid stored within the pores or crevices of any stratum exposed in the hole.

Jan 1, 1922

By José Arce

El presente texto señala la importancia de los métodos geofísicos en la exploración de yacimientos minerales del Perú. De acuerdo a las diferentes situaciones geológicas se elige el método más adecuado. Para el caso de vetas de gran buzamiento con sulfuros metálicos se utiliza el método electromagnético autopotencial, cuyo accesorio es la resistividad; para el caso de Mantos de bajo ángulo o bolsonadas con sulfuros metálicos, se cuenta con el método electromagnético y para la estructura de sulfuros diseminados Placeres Hierro, pirrotita, cobalto, níquel, se emplea la polarización inducida y el electromagnético, cuyo accesorio es la resistividad y gravimétrica.

Jan 1, 1972

By J. M. Toguri, K. Grjotheim

It is known 1,2 that the equilibrium between titanium metal, TiCl2 , and TiCl3, in a solvent of molten metal chlorides, is influenced both by the total amount of dissolved titanium and by the type of solvent. Assuming that the trivalent titanium forms the complex ion Ti111 Cl4, the equilibrium reaction may be expressed by the following equation, (Me) TiIII cl4+ 1/2 Ti = 3/2 TiII cl2+ (Me) Cl The ideal ionic equilibrium constant for this reaction is, Where the N's are the molar ionic fractions in the equilibrium melt, and (Me) the different types of cations present in the equilibrium mixture. The following thermodynamic relation is derived between Kand the concentration of cations in the equilibrium melt, mix The N"S are the equivalent ionic fractions, and so forth are constants corresponding to the standard changes in free energy for reactions in melts where only the cation indicated is present, and f (y1) is a function of the activity coefficients in the equilibrium mixture. When this term vanishes, a simplified linear relationship between In Kideal and the concentration is obtained. The simplified relationship has been applied with satisfactory results to the experimental data of Mellgren and pie,' and Kreye and Kellogg.2 MANY existing methods for the production of light metals involve the reduction of their respective metal halides in the presence of salt melts composed of alkali or alkaline earth chlorides. In such a solution phase, the light-metal halide may undergo stepwise reduction from a higher, to a lower valence, and finally to a zero valent state. In this connection, the disproportionation equilibrium is of great interest. In the case where the higher valence is three and the lower valence is two, the disproportionation equilibrium may be written as follows, 3 Me11 = 2 Me111 + Me [I] If this equilibrium occurs in a salt melt containing a large excess of alkali chlorides, a typical ionic melt is obtained. It is then possible to formulate the cation equilibrium: 2 Me+h' + Me = 3 Me++ [II] Reaction [11] is analogous to a cation exchange reaction. It has been shown thermodynamically that the equilibrium constant for such a reaction in 2

Jan 1, 1960

By Ivan Kwei Liu Kam

O presente trabalho propõe a carbonetação a laser de ferro puro para a formação de uma camada endurecida na superfície. A formação de uma camada dura permite obter peças com melhores propriedades tribológicas, mas sem alterar as propriedades volumétricas do sólido. Foram realizados experimentos em quatro condições de tratamento a laser, com uso de uma fonte do tipo fibra de Yb:vidro. Análises microestruturais e de dureza mostraram a formação de camada ledeburítica e martensítica, dependendo das condições experimentais, até cerca de 50 µm de profundidade. Análises por calorimetria permitiram, também, verificar que a absortividade do laser na peça variou entre 30 e 46%. Estes resultados mostram que o uso de laser para a carbonetação de peças ferrosas, com a metodologia proposta, permite um alto rendimento, alta dureza da superfície e baixo aporte térmico ao material.

Aug 7, 2018

By J. Ventura

El presente texto señala algunos aspectos en el diseño de proyectos de explotación de minas metálicas a cielo abierto respecto a los subterránes. Para ello, es necesario evaluar la importancia de la tasa de recuperación del metal, la cual es producto de las tasas elementales de recuperación en la explotación y la planta. Asimismo, los métodos de extracción selectiva tieneN mayor influencia sobre la tasa de recuperación global que los resultados de la planta de concentración por los cuales se suele tradicionalmente desarrollar esfuerzos considerables para lograr tan sólo como uno o dos puntos más de rendirniento. También la extracción selectiva tiene mayor influencia sobre los resultados financieros.

Jul 1, 1977

By Zephaniah Varley, Dominic Parmantier, Paul Schmall, Richard Martin, Red Robinson

Sequential excavation of the Beacon Hill Station has been accomplished in highly complex and inter-layered sand, silt, and clay soils with multiple perched groundwater tables. Successful excavation has required the installation of a deep dewatering well system used to depressurize sand layers above and within the excavated tunnel faces. In addition, the presence of sand layers in the crown of the Platform Tunnels required jet grouting at depths of up to 49m (160-ft). This paper discusses the design intent, construction, and effectiveness of the dewatering system and the selective jet grouting of sand horizons and shaft break outs for the successful construction of the deepest SEM station excavation ever completed in the United States.

Jan 1, 2007

By Gabriel Duarte de Andrade, Arnaldo Veronêz Júnior

Em um processo de sinterização, a velocidade da máquina de sínter deve ser controlada, com o intuito de garantir que o ponto final de queima da camada a sinterizar esteja dentro de uma faixa que possibilitará elevada produtividade. Este artigo apresenta um modelo físico que descreve o movimento da frente de queima da camada ao longo do leito e o controle de velocidade implantado no sistema de automação de nível 2 da Sinterização da ArcelorMittal Tubarão. O controle de velocidade foi proposto para manter o ponto final de queima em torno do valor do setpoint escolhido. Ao longo dos anos, as condições operacionais da planta de sinterização mudaram em razão da variação da qualidade dos minérios que compõem a mistura. Nesse contexto, o controle foi avaliado e apresentou resultados satisfatórios, permitindo à operação uma forma de controlar o processo sem adicionar atrasos relacionados à tomada de decisão.

Oct 1, 2019

By Bruce Clements

The Bagdad mill, located near Bagdad, AZ, was built in 1977 with a designed mill capacity of 36.3 kt/d (40,000 stpd). An autogenous mill-ball mill crusher (ABC) grinding circuit was chosen. The original mill contained three independent grinding circuits. Each contained one 9.75m-diam x 4-m-long (32-ft-diam x 13-ft-long) fixed-speed autogenous mill, a4.7-m-diam x 6.7-m- long (15.5ft-diam x 22-ft-long) ball mill and one 2. 1-m-diam (7-ft-diam) short head cone crusher. Total installed power per grinding circuit was about 8.4 MW (11,350 hp), with 5.9 MW (8000 hp) in the autogenous mill, 2.2 MW (3000 hp) in the ball mill and 261 kW (350 hp) in the crusher (Fig. 1). The autogenous mills were designed to be able to operate semi-autogenously. However, they were never converted to semiautogenous grinding (SAG) mills. As a result of this design, only about 4.1 MW (5450 hp) of the designed power is used in the autogenous mills. The grinding circuits are closed, with 2.4 x 6 m (8 x 20 ft) double-deck vibrating screens. A series of conveyors re- turn screen oversize underneath the mill coarse ore stockpile to feed the crushers. Variable speed belts feed the crushers and control power draw. Crusher product reports directly to the tail end of the autogenous mill feed belt (Fig. 2). A magnetic sensor detects tramp iron in the autogenous mill-crusher circuit.

Jan 1, 1992

By O. C. Garst

"The lightness and relatively high strength per unit weight of certain magnesium alloys have interested designing engineers for many years. Ever since the noted investigator Bunsen3/ first produced the element by electrolysis of the fused chloride in 1852, utilization of this light metal has been considered. Magnesium is widely distributed over the earth's surface in high-grade as well as low-grade deposits; it occupies eighth place in the list of elements arranged in order of their decreasing abundance, as there is 2.24 percent magnesium in the earth's lithosphere. Even though the element is distributed widely in the form of relatively insoluble: minerals and also as soluble salts in sea water and spring water, as well as being an indispensable constituent of plants and animals, the technology of magnesium was slow development. This slowness of development was first caused by confusion or the part of the early investigators who thought that magnesia, magnesite, magnetite, and the pyrolusite-type manganese ores were compounds of the same metal. At one time the metal that we now know as manganese was called magnesium, and magnesium was called either magnium or talcium. In addition to this coon, the chemical activity of the metal, especially at high temperatures, created problems that are still difficult to solve.With the advance of science in all branches, .methods for -he production of magnesium were developed. The methods first used for producing the element were: (1) reduction of magnesium salts with alkali metals,4/ (2) electrolysis of aqueous solutions of magnesium salts, and (3) electrolysis of fused magnesiun salts.The first attempts to produce magnesium by the carbothermal reduction of magnesia were failures as sufficient thermodynamic knowledge concerning the reversibility of the reaction between magnesia and carbon was not at hand. As the igneous electrolytic Method for making the element was more easily controlled than the others and. yielded more metal per unit of energy, considerable work was expended on the improvement of this process. The work in this field paralled that on the electroreduction of aluminum and the alkali metals. For several years the entire magnesium industry was dependent on this igneous electrolysis process for its supply of the metal, but as demand for the metal increased and more scientific knowledge was available, other processes were developed. Today magnesium is produced by the electrolysis of molton magnesium chloride electrolytes, the carbothermal reduction of magnesia, in arc furnaces followed by shock cooling of the furnace gases by a coin inert atmosphere, and the silicothermal reduction of calcined dolomite in stainless steel retorts."

Mar 1, 1946

By Rodrigo Prestes Limberger

A investigação do comportamento de um mandril com diferentes diâmetros ao longo de seu comprimento no forjamento incremental em matriz aberta de eixos vazados para aerogeradores é estudada. Tem-se por finalidade a fabricação de um mandril que se adeque à peça forjada e atinja o formato proposto. Através do uso de simulações numéricas computacionais com o software Simufact.forming 12, e simulações com o material modelo plasticina, possíveis geometrias de mandris foram estudadas, variando a angulação na região de troca de diâmetros ao longo do comprimento. Foram estudados ângulos de 0º, 30º e 60º, analisando o comportamento da fluência do material na região.

Aug 16, 2017

By P. Perruzza, R. Grandori, A. De Biase, A. Ciamei, A. Busillo

The Turin metro alluvium soil is mainly made of large boulders, cobbles and gravel , few sand and almost no fines. This grain size curve is out of the range of application for EPB and Slurry TBMs. In order to bore 5 of the total 7,5 kms of Line 1 tunnel, two specially designed Lovat EPB TBMs were utilised in combination with a systematic non structural pre-grouting of a small volume rectangular slab just above the tunnel section. The same pre-grouting was not however applicable for lack of access on surface in some sections of the remaining 2,5 km of tunnel that had to be bored below important buildings/structures, with under ground water pressure up to 1,5 bar, with curves radius of 180 m only. For these more critical sections it was necessary to study and implement a new technical solution and improve the capacity of the TBM to work efficiently in EPB mode even in this unsuitable ground and overall conditions. After months of studies the selected and adopted solution has been to inject inside the cutterhead chamber, in addition to the almost standard foams & polymers additive mixes, a suspension of limestone powders. This with the scope of compensating the lack of fines of the natural ground with rock powders.

Jan 1, 2005

By Luis-Fernando Contreras, Juliano Maran, Richard LeSueur

A risk study was carried out at the Cerrejon coal mine in order to assess the impacts of pit slope failure in terms of safety of personnel and destruction of equipment with economic consequences. Results of the assessment enabled the definition of risk treatment requirements and the identification of key aspects to consider in a risk treatment plan. The approach included the following tasks: (1) Assessment of the total probability of failure (POF) representative of the stability conditions of typical footwall and highwall slopes. For this purpose, stability analyses were carried out to define the Design POF, which accounts for the variability of strength parameters and represents the normal conditions considered for slope design. Strength parameters for highwall slope analysis were derived from borehole data obtained with a geotechnical drilling campaign. The Total POF was estimated through the use of Source Response Diagrams (SRD) in order to incorporate other sources of uncertainty not accounted for, like changes in geometry, variability of rock conditions due to geological or operational factors, changes in groundwater conditions and occurrence of seismic events. (2) Assessment of the consequences of footwall and highwall slope failure on safety of personnel. The assessment was performed through the use of event tree analysis to establish the probability of fatality caused by slope failures, from the Total POF defined in the previous task. This analysis required the evaluation of personal exposure to slope failures. Also, the assessment included benchmarking of acceptability criteria in terms of probability of fatality and the evaluation of options of risk mitigation to comply with these criteria. (3) Assessment of the consequences of footwall and highwall slope failure in terms of economic losses associated with impact on equipment. The analysis included the evaluation of equipment exposure to slope failures, and it was performed through event tree analysis to establish the probability of an economic loss associated to total or partial lost of equipment, from the total POF value defined in the first task. The magnitude of the economic losses was estimated from the costs of damaged equipment, lost production and site restoration. Options of risk mitigation were also examined in terms of economic losses. The risk assessment process applied to the Cerrejón mine showed how the system can be applied to evaluate the consequences of failure in terms of personnel safety and economics and to identify the more adequate risk mitigation options. The system can be an extremely powerful tool in the mine design process and provides the opportunity to rationalize the geotechnical information requirements, once the risk criteria have been defined by management. The main purpose of this paper is to present the process; therefore, the emphasis has been put on the methodology followed rather than on the actual results obtained.

Jan 1, 2006

By J L. Mauk

 Broken Hills is an adularia-sericite epithermal Au-Ag deposit, hosted in flow-banded rhyolites and overlying rhyolitic pyroclastic rocks in the eastern Hauraki Goldfield. The 7.1 Ma deposit was the largest producer of gold in the eastern Hauraki Goldfield, and was one of very few economic deposits hosted in Pliocene rhyolites. This paper presents the results of a recent study in the upper levels of the deposit. Maps and cross-sections constrain structural and lithological relationships, and the lateral and vertical extent of a breccia pipe û the major feature of the upper levels.   Previous studies in the upper levels of Broken Hills have shown that gold and silver values are concentrated around and within a large breccia pipe, mined by a series of æcaveÆ stopes and in veins. Contour diagrams of Au-Ag data from channel samples indicate that the breccia pipe was a major fluid channel-way for mineralising solutions.   The breccia pipe deposits are part of the dynamic geothermal system that formed the Broken Hills ore bodies; they developed as a result of hydrothermal brecciation in areas of structural weakness within a rhyolite pyroclastic unit that overlies a massive rhyolite lava-flow unit. The main breccia pipe begins near the rhyolite/pyroclastic contact, having the shape of an inverted, inclined cone, and consists of silicified breccia, stringers of quartz, and irregular patches of clay-altered country rock. Smaller zones or pockets of hydrothermal eruption breccia are silicified and contain low grade gold in the matrix and in the adjacent silicified wall rocks.   Quartz has been classified according to its physical characteristics as seen in situ and hand specimens indicate that vein definition decreases upwards, perhaps as a result of changing lithological conditions and/or increasing proximity to the paleosurface. Hydrothermal quartz is widespread as veins and as a replacement mineral, or lining fractures and cavities and overgrowing rock fragments. Breccias contain vein quartz, but some quartz veins cross-cut breccias, indicating that vein and breccia formation was relatively synchronous and overlapped in time.   Disseminated gold-silver mineralisation is associated with vein quartz and silicic alteration of the wall rock within the breccia pipe. The auriferous zones are highly irregular and erratic, and sampling results show a wide range of gold-silver ratios, suggesting that highly volatile physiochemical conditions prevailed during mineralisation.

Jan 1, 2005

By Michael Young, Josh Rubenstein, Michael Cooper, Tom Shouldice, Dan Curry

"Xstrata Nickel Australasia’s Cosmos plant in Western Australia is currently implementing a debottlenecking project to increase nickel output while maintaining metallurgical performance and a low unit cost for production. Mineralogical analyses indicated that the processing bottlenecks could be removed by simply reconfiguring portions of the circuit as well as adding capacity with technical advancements – notably an IsaMill™, Jameson Cell, Wemco® SmartCell™ and Larox Filter.The Wemco® SmartCell™, which is particularly suited for coarse mineral flotation, and Jameson Cell, which is particularly well suited for fast floating and fine minerals, combine as rougher scalpers to complete the main stream portion of the flotation circuit. Addition of the two new cells meet the required flotation capacity to handle the forecast increase in nickel feed grade and tonnage.The addition of an IsaMill™ for regrinding allows the SAG mill to produce a coarser primary product, thus enabling increased throughput. The advantages offered by the IsaMill™ include operation in open circuit (internal classification), an inert grinding environment (ceramic media) for better downstream flotation (“clean” new surfaces), compact footprint (easy to retrofit into existing plant) and energy efficiency. With the new rougher capacity addition, the remaining original plant cells were reconfigured to suit the new regrind mill and cleaning requirements. The existing 24 m2 Larox pressure filter was replaced with a larger 32 m2 unit to dewater the increased concentrate output.The paper describes the upgrade at the Cosmos concentrator with particular emphasis on the mineralogical data and metallurgical benefits associated with the changes.INTRODUCTIONThe Cosmos concentrator is located 680 km northeast of Perth in Western Australia. The deposit’s development and operations were started in 1999 by Jubilee Mines NL, Cosmos’ previous owner, with the first production of nickel concentrate in April 2000. The Cosmos concentrator treats a komatiite hosted high grade nickel sulphide ore, with sulphides being predominantly pentlandite and pyrrhotite with lesser amounts of pyrite and chalcopyrite."

Jan 1, 2010

By Moacir Medeiros Veras

A tecnologia de sensor-based sorting faz uso de sensores high-tech para pré-concentrar seletivamente partículas de minérios que tenham teores toleráveis para planta de beneficiamento, rejeitando as partículas que são totalmente estéreis ou rejeitos. A pré-concentração de carvão assistido pelo método Dual Energy X-Ray Transmition possibilita separar seletivamente o carvão com melhor quantidade de matéria orgânica das rochas silicáticas com maior densidade. O objetivo desse trabalho foi investigar a afinidade da tecnologia de sorting na pré-concentração do carvão mineral da Carbonífera do Cambuí/PR assistido por sensor de raios-x. Os testes foram realizados em dois lotes cujo range granulométrico foi -4”+2” e -2”+1”. A pré-concentração foi feita em 2 cortes de separação, o primeiro para retirar o rejeito e o segundo para obter 2 tipos de produtos. Os resultados indicaram que 52,15% da massa foi rejeitada, concentrando 47,85% do material de carvão na fração média -2”+1”. Na fração grossa -4”+2” foi rejeitado 62,51% da massa e concentrado 37,49% de carvão. As análises imediatas dos pré-concentrados mostraram que na fração grossa houve redução de 44,57% de cinzas totais e houve aumento de 4,59% para 8,29% de enxofre [S], enquanto na fração média a redução foi de 36,98% de cinzas totais e de 1,19 % [S].

Oct 30, 2017

By Charles F. Seemann

It is with considerable trepidation that I set out to defend "litigation" to Design Professionals (DPs), as a better method of resolving disputes than arbitration, in the light of my personal feeling that an increasing amount of America's productive process is being squandered in litigation. Newer methods of dispute resolution, particularly arbitration, are fashionable, and opponents of these schemes risk being viewed as cynical or self-serving. My quandary is heightened since for some smaller disputes, arbitration seems clearly the better choice. I must concede, for example, that when the cost of dispute resolution--i.e., the cost of the process (such as arbitrators fees, attorneys fees, etc.), plus the cost impact of the non-productivity of involved employees--approximates the amount of the dispute, controlling that cost may be as important as a correct resolution. This principle is particularly true for small disputes arising during the progress of a project; it is probably more cost-effective for all parties to resolve their disputes quickly than permitting the dispute to drag out.

Jan 1, 1988

By K. Mallikarjuna Rao

There are several methods available to estimate deflection and ultimate Capacity of laterally loaded piles. In this investigation an attempt has been made to verify the existing methods for prediction of ultimate lateral resistance and deflection with the laboratory and field test results reported in the literature. A 75 pile loading test data obtained from the literature was used to evaluate two methods designed to predict the ultimate lateral resistance of rigid piles and three methods designed to predict the lateral deflections of rigid piles and four methods designed to predict the lateral deflection of flexible piles subjected to lateral loads. The accuracy and precision of each method is quantified statistically. The statistical results of the overall analysis indicate that the mean values of the ratios of predicted to measured lateral capacities vary from 0.62 to 1.14 with an average of 0.88. However, the settlement predictions were much more widely scattered than the ultimate load predictions and in general all the methods have a tendency to under predict the deflections. A new method is proposed by modifying the Broms's method to estimate the lateral deflections of free headed rigid and flexible piles separately. The proposed modified methods were found to be reasonably good in comparison to existing methods and to overestimate deflections.

Jan 1, 1996

By Carlos Aranda S

El presente trabajo describe el proceso pirometalúrgico convencional y actual en el tratamiento de los concentrados de cobre en el Perú. En ese sentido, se comparan los procesos antiguos con los nuevos, así como el uso de equipos últimos como el Outokumpo, Noranda,Hitsubishl, Worcra, TBRC, Klvcet y otros. De acuerdo a esto, los cambios se efectuaron solo en el tamaño de los hornos y se recomendó que en el uso de las dos fundiciones de cobre: CENTROMIN y Southern Perú Cooper Corp, se utilicen las tecnologías más adecuadas dentro de las condiciones menos óptimas y así competir con países latinoamericanos como Brasil, Chile y México.

Oct 14, 1980

By E. Chin

The domination of Bangladesh's mineral industry by natural gas was in for some possibly significant changes. A modest flow of crude oil was struck in a gas development well in the northeastern corner of the country. This was the first commercial flow of crude oil in Bangladesh. All crude oil was being imported, which cost a significant proportion of the nation's foreign exchange earnings. The development of an oilfield producing only a few thousand barrels per day would be a welcome help to the economy. Additional exploration at a 1985 coal discovery in the northwest indicated a considerable reserve of good-quality coal at a depth suitable for mining. If the coal is mined, it would be a boon to the local economy because natural gas was not available in the area.

Jan 1, 1988