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By Wilber Manrique

El yacimiento Cerro Corona constituye una mineralización de cobre y oro, que se encuentra emplazado en una roca intrusiva dioríticos y estratos gruesos de calizas. Para alcanzar el avance en las proyecciones de minado y de estabilidad de taludes en el Tajo del Cerro Corona y el agua en los acuíferos es necesario crear un sistema de drenaje, conformado por 6 pozos Operativos y 21 piezómetros activos que se encuentran en el tajo y en alrededores del mismo. El Sistema de Drenaje cumple la función de deprimir el nivel piezométrico de los acuíferos presentes en el tajo. En ese sentido, el presente trabajo describe los resultados de las mediciones de monitoreo de pozos de drenaje y piezómetros que conforman el sistema de drenaje e interpreta dos principales acciones que se ejercen sobre el sistema hidrogeológico en términos de balance (recarga por infiltración de agua de lluvia y salidas por extracciones del drenaje de agua subterránea) y la correspondiente respuesta hidrodinámica del sistema hidrogeológico (piezometría).

Sep 21, 2013

By F. D. DeVaney

Manganese-bearing deposits f the Leadville, Colo., district are of two distinct types. Manganosiderite, a combined or intimately mixed ferrous and manganous carbonate, occurs in unaltered zones as the predominant mineral. From 50 feet below the surface to as deep as 900 feet, psilomelane and wad, both black manganese oxide minerals, are found in intimate contact with hematite and limonite. A typical analysis of the black oxide ore shows 20.08 percent Fe, 18.64 percent Mn, 15.91 percent insoluble, 14.91 percent moisture, 0.94 percent Zn, and 2.13 percent Pb. A considerable tonnage of the oxide ore has been mined for production of spiegeleisen and for other purposes.

Jan 1, 1940

By F. D. DeVaney

Manganese-bearing deposits of the Leadville, Colo. district are of two distinct types. Mangano siderite, a combined or intimately mixed ferrous and manganous carbonate, occurs in unaltered zones as the predominant mineral. From 50 feet below the surface to as deep as 800 feet, psilomelane and wad, both black manganese oxide minerals, are found in intimate contact with hematite and limonite. A typical analysis of the black oxide ore shows 20.08 percent Fe, 19.64 percent Mn, 15.91 percent insoluble, 14.91 percent moisture, 0.94 percent Zn, and 2.13 percent Pb. A considerable tonnage of the oxide ore has been mined for production of spiegeleisen and for other purposes.

Jan 1, 1940

By S. Badr, R. Mendoza, M. U. Ozbay, M. D. G. Salamon

ABSTRACT: The use of coal pillars at depth is fraught with problems due roof control difficulties and the possible occurrence of coal or pillar bumps. In the USA the largest and most important application of pillars at depth is in longwalling, where chain pillars are the customary supports of the multiple entry developments. At first, the chain pillars were designed using conventional approaches, where the principle is that the strength of the pillar should exceed the load imposed on it. Such approach to design led to larger and larger pillars at great depths, but instead of eliminating, it tended to aggravate the roof control problems. Eventually the idea was born that small sized yielding pillars, which have proved to be successful elsewhere, might provide the answer to this pressing problem as well. The aim of this paper is to study the modes of pillar failure at great depths, using two solution methods. The first of these comprises some elementary solutions obtained with the aid of a simplified conceptualization of the rock mass. This model consists of a strain-softening coal seam sandwiched between two stratified masses. The second approach utilizes FLAC3D, which is a commercially available three-dimensional numerical modeling software package. To gain a better insight, both the strain-softening and ideally plastic Mohr-Coulomb constitutive laws embodied in FLAC3D were exploited. As expected, the width to height ratio of the pillar has proved to be the primary factor that determined the behavior of the pillars. Narrow pillars fail in a stable manner without the occurrence of instabilities. Intermediate w/h ratio pillars under the appropriate loading conditions, may fail suddenly and may even collapse totally. Squat pillars do show the potential for sudden, coal bump like side failure, but because the remaining large width of the inner core, the ruble around the pillar provides sufficient confinement so as to reestablish stability. Finally, the study revealed that the traditional Mohr-Coulomb law does not provide a useful insight into the failure of coal pillars. RESUME: L’utilisation des piliers de charbon dans les mines souterraines de grande profondeur occasionne des problèmes due aux difficultés de control de plafond et possibles fracture ou explosions au niveau des piliers. Aux Etats-Unies d’Amérique, l’utilisation des piliers dans les mines souterraines de charbon comme moyen de support est considèrees comme étant la plus grande et la plus importantes des méthodes utilisée dans le ‘’ longwalling method’’ ou une série des piliers sont disposé de manière à supporter les multiple entrées d’exploitation de charbon. En premier lieu, cette série des piliers étaient construit de manière conventionnelle avec un principe basé sur le fait que le poids exerce sur les piliers doit être inférieur a la force que ces piliers exerce sur le plafond. Ce principe a conduit a ce que le volume des piliers augmente au fur et à mesure que la profondeur au de la mine augmente. Malheureusement, au lieu de résoudre le problème de support, ce principe n’a fait qu’aggraver le problème de contrôle de plafond. Eventuellement une idée s’est dégagé allant du fait que les piliers endommagés de taille moyenne qui se sont avérés être efficaces ailleurs, pourraient fournir un indice à ce particulier problème. Le but de cette recherche est celui d’étudier les différent types de ruptures qu’un pilier peut occasionner lorsqu’il est utilisé a grande profondeur, tout en utilisant deux possible méthodes. La première d’entre elle comprend quelques solutions élémentaires obtenues avec l’aide d’une méthode simplifié et conceptuelle de la masse de la roche. Ce modèle consiste à prendre en sandwich la bande de minerais de charbon entre deux masses stratigraphiques sans pour autant endommager le plafond. La seconde méthode nécessite l’utilisation du ‘’ FLAC3D’’, qui est un logiciel commercialisé disposant d’un modèle numérique en 3 dimensions. Dans le but d’obtenir

Jan 1, 2003

By Juan Rassmuss

El presente artículo señala el valor del azufre y la influencia del método de beneficio en lsu explotación. Asimismo, se describe los yacimientos de Piura y los de Báyovar, como del extremo norte está Ticsani, Tutupaca, Yucamani, Cano y en el Sur, Paucarany. La formación de estos yacimientos se debe a lla oxidación parcial de sulfuro de hidrógeno de origen volcánico, a excepción de los yacimientos de Bayovar y Piura, considerados como productos resuidual de petróleo.

Jul 1, 1956

The coal-bearing areas of Kansas cover approximately 18,800 square miles (23 percent of the state's total area). Coal in Kansas ranges from lignite to high volatile bituminous, located principally in the south-eastern part of the state. Kansas reserves are estimated to be 987,500,000 tons, approximately 0.2 percent of U.S. reserves. Coal beds generally occur in thin seams up to five feet thick. The overburden-to-coal stripping ratios in Kansas are among the highest in the nation, typically 20 to 1, with some ratios up to 35 to 1. The first commercial coal mining operation in Kansas opened in 1865 at Fort Scott in Bourbon County. As in other states, coal production in Kansas increased during the industrial revolution, and then fell as industry converted to alternative fuels. Production peaked in 1916 and 1917, with annual production of 7,250,000 tons. Coal production today is by surface mining methods. The Kansas regulatory program was approved April 14, 1982; the Abandoned Mine Land Program was approved February 1, 1982; and the emergency program authority was approved January 10,1989.

Jan 1, 1992

By CHARLES L. WRIGHT

Coals may be divided into six classes-anthracite, semi anthracite, semibituminous, bituminous, subbituminous, and lignite. The first three cla~ can be distinguished by dHferences of composition, particularly the proportions of fixed carbon and the ratios of the fixed carbon to the volatile matter in the cools. The last three classes can be distinguished by di:fferences in physical character, chiefly in color and in manner of weathering. Lignite is brown, not black, and has generally a woody look, but it weathers in much the same way as subbituminous coals. On exposure to the air lignite slacks or crumbles. The lumps check and fall into small irregular pieces that exhibit a decided tendency to separate into extremely thin plates. Hence lignite deteriorates greatly during storage or long transportation. The most characteristic feature of the composition of lignite is a large percentage of moisture. '!his high moisture content reduces the fuel value of freshly mined lignite, and the partial evaporation of moisture, on expooure, causes th6 fuel to check and fall to pieces. Consequently, attempts to increase the efficiency of lignite as a fuel involve reducing its percentage of moisture and increasing its ability to endure storage and transportation. Both these results are accomplished by briquetting.

Jan 1, 1911

By E. M. Spokes

Starting in 1980, a committee of the National Research Council studied the question of why some underground coal mines are safer than others and what could be done to improve the ones with poorer performance. The results indicated that safety is improved by management commitment to safety, by cooperation between labor and management on safety matters, and by quality training of employees and managers. Younger miners have higher accident frequencies, but are less likely to be killed or permanently disabled by a lost-time accident. Methods for improving safety performance are proposed.

Jan 1, 1987

By T. R. Ellis

A number of important international events took place in 2001 in the development and evolution of mineral valuation standards internationally. In Canada, the CIMVal Committee released a draft discussion paper for public and industry comment on principles to guide the development of the planned Canadian mineral property valuation standard. The International Accounting Standards Board (IASB) received comments on its Extractive Industries Issues Paper. IASB will decide whether the financial statements of public mining and petroleum companies will be allowed to provide the value of mineral and petroleum assets on a current value basis instead of an historic cost basis. The author led the Extractive Industries Task Force of the International Valuation Standards Committee (IVSC) in developing its submission to IASB. IVSC intends to develop an extractive industries valuation section for its International Valuation Standards, which could support the planned IASB standard. In Australia, AusIMM has carried out an in-depth review of its highly regarded VALMIN Code. The AusIMM's MICA subdivision organized the VALMIN ‘01 Conference in Sydney, Australia, with a range of international and current issues papers published in the VALMIN ‘01 book. Considerable support for the IVSC initiative was evident at this conference. The results of the review of the extractive industries submissions to the IASB are expected to be released in early 2002. The CMMI Congress in Cairns, Australia in May 2002 is likely to prove to be an important forum for continued discussion of the development and implementation of international standards and qualifications for mineral valuation. The outcomes and implications of these events are discussed.

Jan 1, 2002

In longwall mining, premining prediction of methane emission rate depends on a number of geological factors, geographical factors, and operational factors. These same factors also can impact the selection of a specific degasification system. This study proposes a principle component analysis (PCA) and artificial neural network (ANN) approach to predict the ventilation methane emission rates of U.S. longwall mines and the optimum combination of degasification boreholes based on the given characteristics of the mine. Artificial neural networks, more than conventional computer models, are adaptable systems that can solve problems such as non-polynomial or very complex relationships that are difficult to describe mathematically. Data on ventilation emissions and degasification system design were obtained from 63 longwall mines in 10 states and were combined with corresponding geological, geographical, and operational parameters for the period 1985-2005. PCA was used to determine the variables that most influence ventilation emissions and degasification system design. Different combinations of variables in the data set and network structures were used for network training, cross-validation, and testing. The resultant ANN models predicted ventilation methane emissions with a 90-95% accuracy and were superior to multi-linear and second order non-linear models. The ANN-based expert classification system was able to classify the design of the degasification system (no degasification, gob vent borehole, horizontal and gob vent borehole, and horizontal, vertical and gob vent borehole) with more than 80% accuracy. The models can be used as prediction and decision tools for the ventilation emissions and degasification system selection for specific site and mine-design conditions.

Jan 1, 2009

By S Sabanov

Determining ventilation system model inputs from the field test work has been produced in the working oil shale mine which has been in production since the early 1970s. At this mine room-and-pillar with drill-and-blast methods are used. The mine has a complicated ventilation system to supply fresh air for the eight mining production areas on the radius of about 12 km. The main purpose of the experimental test works was to obtain data for estimation of an optimum cross-section area for a new ventilation shaft. Experimental test works included measurements of air volume and fan pressure using five different modes of intake air through the ventilation shafts system. Measurements of airway friction factors were obtained during the ventilation surveys to determine characteristic friction factors for the intake airway. The results of the measurements will be used for further air flow simulation processes required for design of new additional ventilation shafts in the oil shale mine. Results of the study can be useful in estimation of frictional pressure drop in oil shale mine conditions.CITATION:Sabanov, S, 2017. Determining ventilation system model inputs from field test work in the oil shale mine, in Proceedings Australian Mine Vent Conference 2017, pp 47–50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By A. A. Stripling

The Cretaceous limestone wells of the Mara/Maru-caibo Dist. of Venezuela are extremely prolific producers. To maintain production on cessation of natural flow, large scale gas-lift operations were commenced involving high production rates on caring Flow. For the design of these gas-lift installations it was essential to have some knowledge of the pressure gradients involved in casing flow, so that the required injection pressures, optimum gas injection raws, etc., could be forecast. This paper presents a method of calculating these annular pressure gradients. Basically the method makes use of an energy balance equation coupled with an empirical energy loss factor derived from field data. The calculations have been put in a form suitable for "punch card-type" calculating machines. A set of gradient curves for Mara/Maracaibo conditions covering flow rates up to 12,000 B/D, and GOR's of 500 to 2,000 cu fd/bbl is presented. From these curves the flowing BHP can be predicted from surface data and the vertical pow performance under varying conditions of gas injection can be estimated. The method has been applied to La Paz and Mam gas-lift operations for over three years and has given consistently accurate results. INTRODUCTION The Cretaceous limestone fields of the Mara/Maracaibo area in Venezuela are characterized by the presence of widely distributed fissure systems. Under these conditions individual wells frequently have extremely high potentials and such wells are generally flowed on the casing-tubing annulus in order to reduce the pressure loss in vertical flow. To maintain production on cessation of natural flow, an extensive gas-lift system was planned. As a first approach to this gas-lift design problem, an attempt was made to construct a set of empirical flowing gradient curves from the available subsurface pressure data. Such a method has been used successfully for tubing-flow conditions in California by Gilbert'. Unfortunately, the empirical construction of casing-flow gradient curves presents additional difficulties, as pres- sure bombs cannot bc run in the casing-tubing annulus against high rates of flow. Thus, the Full flowing gradients cannot be defined by actual measurement and the best that can be done is to obtain spot pressures at the tubing shoe. Under these conditions a vast accumulation of BHP data is required to construct a set of gradients. To the La Paz and Mara fields the majority of the available flowing pressure measurements fall into a relatively narrow GOR range, in the neighborhood of the solution ratio. While there appeared to be reasonable prospects of constructing gradient curves for this limited range, measurements at higher GOR's, which were of major interest for gas-lift operations, were relatively few and the prospects of constructing empirical curves cor~spondingly remote. As an alternative approach, the possibilities of a mathematical analysis of vertical flow conditions were investigated. May and Laird2fV n 1934 presented an excellent analysis of the vertical-flow conditions in the Anglo-Iranian Oil Co.'s fields. Their analysis was based on an energy-balance equation and calculated the losses due to kinetic energy, friction and slippage separately. By combining these losses with the total calculated available energy, the required depth-pressure traverse could be deduced. On applying the method to La Paz conditions, good results were obtained for tubing flow at high tubing-head pressures. However, for lower wellhead pressures (300 psi and under) the discrepancy between calculated and measured values increased appreciably. It was considered that this was probably due to energy losses caused by slippage or liquid hang-up in a continuous gas phase, for which it was difficult to visualize any analytical approach. In 1952 Poettmann and Carpenter4 presented a method of pressure gradient calculation which, while based on an energy-balance equation similar to that employed by May and Laird, made no attempt to evaluate the various components making up the total energy loss resulting from irreversibilities of flowing fluids. Instead, they proposed a method of analysis which assumed that all significant losses for multiphase flow could be correlated in a form similar to that of the Fanning equation for frictional losses in single-phase flow. They then derived an empirical relationship linking measurable field data with a factor which, when applied to the standard form of the Fanning equation, would enable the energy losses to be determined. The total available

By Steve McAlister, Colin Sprake

"Enhanced gravity concentration machines have been applied successfully in the following areas of precious metal recovery flowsheets:1. Primary Grinding Circuits2. Shaking Table Tailings3. Pre-Concentration of Leach Feed4. Flotation Concentrates -•, Flash•, ConventionalAlthough great progress has been made, the ability to produce directly smeltable concentrates still remains elusive. Even without this ability, centrifugal concentrators are finding wideningapplications in precious metal concentration:1) PRIMARY GRINDING CIRCUITSEnhanced gravity concentration technology has largely replaced jigging as the technology of choice in precious metal grinding circuits worldwide. The benefits of using a centrifugal field to concentrate both coarse and fine gold are well documented but the placement of these machines within grinding circuits is still evolving. Conventional wisdom dictates that the best location for enhanced gravity machines is cyclone underflow on account of the elevated grade found in this stream when compared to cyclone feed or overflow. Plant operating experience at both large and small scale indicates that there are compelling arguments to place ENHANCED GRAVITY MACHINES on cyclone feed instead. At least two new plants, presently in the detailed design stage will incorporate gravity circuits that treat mill discharge or cyclone feed, Teck Cominco’s Pogo and Newcrest’s Telfer Expansion.Current Conventional PracticeThe current stream of choice for enhanced gravity concentration within grinding circuits is cyclone underflow although recent information indicates a swing toward cyclone feed. Here are some of the arguments for treating a portion of cyclone underflow:"

Jan 1, 2003

By E. C. Lane

This paper is the first putt of a report giving the results of the Bureau of Mines' twenty-third semiannual survey of motor gasoline marketed in the United States. A companion report, Part II, is in preparation and will give a more detailed discussion of the whole survey. Results of the determination of copper-strip corrosion, color, sulphur content, copper-dish evaporation residue, and gum content as given by the Bureau of Mines steam-oven method will be presented in the second paper, which will also include the prevailing retail price and the tax at the time the sample was taken. This paper deals specifically with data relative to gravity, Reid vapor pressure,' and distillation (method 100.13).6 The samples tested were divided into "competitive-price gasolines" and "premium-price motor fuels," a method of presentation that was begun with the twenty-second semiannual survey. A total of 312 samples were collected from service station pumps in 20 cities throughout the United States. Of this number of samples, 207 were "com-petitive-price gasolines" and 106 were "premium-price motor fuels." All of the samples were collected in March, 1931, and analyzed at the Petroleum Experiment Station of the United States Bureau of Mines at Bartlesville, Okla. "Competitive-price gasoline" includes those fuels that are sold at the generally recognized local base price and all fuels that are sold below that price. All fuels that are sold at an advance over the generally recognized base price are placed in the class of "premium-price motor fuels." These fuels include Ethyl gasolines, benzol blends, "high-test" fuels, and those fuels that owe their "anti-knock" rating to the process of manufacture rather than to the addition of other material such as Ethyl fluid or benzol. The term "high-test" is generally applied to motor fuels that are more volatile than the regular competitive-price gasolines. "High-test" fuels may also have a high anti-knock rating.

Jan 1, 1931

By George Joseph Malina

Contractor chose and Owner allowed concrete to be placed using the arch first principle while excavating the 35'-3" O.D. rock tunnel. The contract included excavating and lining 26,000 L.F. of rock tunnel to 33'-I.D. Concrete was placed at a rate of 90LF per working day using a movable bridge to allow batching, mixing and pumping of concrete adjacent to the tunnel form.

Jan 1, 1981

By R. Tessier, C. R. Larsen

"INTRODUCTIONOn November 10, 1982 Nor and a Inc signed an agreement with Golden Sceptre Resource Ltd. and Goliath Gold Mines Ltd. to construct a mine and milling facility.The Golden Giant mine is located in the Marathon area of north - western Ontario, immediately north of Highway 17 and about- 3.5 km west of Highway 614.With the exception of selected unit processes, the mill was designed for a nominal throughput of 2500 tonnes per day with early operating data to be used to identify sections requiring possible expansion to achieve an ultimate throughput of 3000 tonnes per day.Commissioning of the highly instrumented milling complex which includes crushing, grinding, cyanidation, and carbon in pulp processes commenced in February 1985. After water testing various sub-circuits from grinding through tailings, waste ore was introduced to ensure proper mechanical and electrical operation of process equipment.The first ore was milled as a mixture with waste on March 4, 1985. The first gold bullion was poured April 6, 1985.Initially, ore was only available from mine development at a rate of 700 t/d, which was milled at a minimum rate of 1200 t/d. While regular weekly shut downs of two to three days was useful for mechanical maintenance, changes, and modifications, process tuning was more difficult due to the non-steady operation. As increased quantities of ore became available, regular weekly shutdowns tapered off and process operation improved accordingly. For testing purposes and as ore was available, mill throughput was increased regularly to 2300 t/d and for very short periods of time to nearly 3000 t/d.No major design or operating problem has been encountered to date. The following is a brief description of the milling process and various operating highlights. Process flowsheets are shown in Figures 1 through 6."

Jan 1, 1986

By W. H. Hough, P. B. Leavenworth

Development during 1942 led to the discovery of 26 new fields in the Texas Gulf Coast, as compared with 27 during 1941. Of these, 19 are classed as oil fields, 4 distillate fields, and 3 gas fields. Production from the new fields amounted to 614,467 bbl. to October 1942. Producing Sections.—Discoveries in I942, compared with the previous two years, classified by producing formations, are shown in the following table: It is interesting to note the increase in Wilcox discoveries due to the extensive geophysical campaign that has been con. ducted since 1940. Drilling.—During the year 688 wells were drilled, of which 574 produced oil or gas and 114 were dry. This represents a considerable decline in activity over the previous year, when 1405 wells were drilled in the area, of which 1081 were producers and 324 failures. Jackson County continued to hold the lead, with 222 wells completed. Production.—-Despite curtailed drilling, production amounted to 118,009,451 bbl. for 1942, indicating a slight increase over the 113,726,893 bbl. produced during 1941. The statistics in Tables I and 2 include condensate and distillate as oil production, because many Gulf Coast fields produce oils with a wide variation of specific gravities, all of which are commingled in pipe lines. Table 3 shows by counties most of the activities referred to. The number of wells drilled includes only field wells; not wildcats. Outstanding Fields of 1942 The Texas Gulf Coast covered in this report has 270 more or less active oil and gas fields, including the new discoveries of 1942. Of these the most outstanding from the standpoint of production are listed in Table 4. Each of these fields produced one million barrels or more during 1942. Some of the fields where new extensions are occasionally referred to as separate fields, such as West Columbia and New West Columbia, or Thompson and South Thompson, are combined to give a more accurate outline. Two interesting facts may be noted from this list of some 26 oil fields: (I) that the Lolita field, Jackson County, is the only discovery since 1938 to produce more than one million barrels annually, although there have been 79 discoveries since Jan. I, 1940; (2) that 20 of these 26 fields produce from the Frio. New Fields ALief, Harris County.—Pure Oil Company's No. I Mike Albanese was drilled to 8637 ft. in Cook Mountain shale. After numerous tests the well was completed on Apr. 20, 1942, in a Yegua sand at 7919 to 7924 ft. for 54 bbl. of 52' gravity oil and 3,335,000 cu. ft. of gas through

Jan 1, 1943

By W. H. Hough, P. B. Leavenworth

Development during 1942 led to the discovery of 26 new fields in the Texas Gulf Coast, as compared with 27 during 1941. Of these, 19 are classed as oil fields, 4 distillate fields, and 3 gas fields. Production from the new fields amounted to 614,467 bbl. to October 1942. Producing Sections.—Discoveries in I942, compared with the previous two years, classified by producing formations, are shown in the following table: It is interesting to note the increase in Wilcox discoveries due to the extensive geophysical campaign that has been con. ducted since 1940. Drilling.—During the year 688 wells were drilled, of which 574 produced oil or gas and 114 were dry. This represents a considerable decline in activity over the previous year, when 1405 wells were drilled in the area, of which 1081 were producers and 324 failures. Jackson County continued to hold the lead, with 222 wells completed. Production.—-Despite curtailed drilling, production amounted to 118,009,451 bbl. for 1942, indicating a slight increase over the 113,726,893 bbl. produced during 1941. The statistics in Tables I and 2 include condensate and distillate as oil production, because many Gulf Coast fields produce oils with a wide variation of specific gravities, all of which are commingled in pipe lines. Table 3 shows by counties most of the activities referred to. The number of wells drilled includes only field wells; not wildcats. Outstanding Fields of 1942 The Texas Gulf Coast covered in this report has 270 more or less active oil and gas fields, including the new discoveries of 1942. Of these the most outstanding from the standpoint of production are listed in Table 4. Each of these fields produced one million barrels or more during 1942. Some of the fields where new extensions are occasionally referred to as separate fields, such as West Columbia and New West Columbia, or Thompson and South Thompson, are combined to give a more accurate outline. Two interesting facts may be noted from this list of some 26 oil fields: (I) that the Lolita field, Jackson County, is the only discovery since 1938 to produce more than one million barrels annually, although there have been 79 discoveries since Jan. I, 1940; (2) that 20 of these 26 fields produce from the Frio. New Fields ALief, Harris County.—Pure Oil Company's No. I Mike Albanese was drilled to 8637 ft. in Cook Mountain shale. After numerous tests the well was completed on Apr. 20, 1942, in a Yegua sand at 7919 to 7924 ft. for 54 bbl. of 52' gravity oil and 3,335,000 cu. ft. of gas through

Jan 1, 1943

By A Weber, L MacNamara, H Schreiber

Design and development of the world?s largest flotation cell was completed in 2002. This was the first 257 m3 flotation cell installed in the mineral industry and represents a major development in the design of larger flotation cells. This cell has a 50% increase in volume over the widely installed 160 m3 WEMCO® Smartcell? flotation machine. In the next few years it is anticipated that 257 m3 flotation cells will be incorporated into rougher-scavenger flotation circuits in many more world class copper sulphide concentrators. The prototype 257 m3 cell, No.250 Smartcell? flotation machine was installed at Minera Los Pelambres in the front of Row 1 in the existing rougher flotation circuit. This cell is followed by nine No. 130 Smartcell? flotation cells. After the successful development phase, this unit has been incorporated as part of a row of No. 250 Smartcell? flotation machines at Minera Los Pelambres. A key to the successful development of the equipment has been the emphasis placed on fundamental hydrodynamic scale-up criteria. Hydrodynamic factors include superficial gas velocity, water (pulp) circulation through the draft tube, and pulp mixing (distribution) characteristics. This paper will review the scale-up criteria of the No. 250 flotation cell, and present a case study of the in-plant equipment testing. The case study will document the metallurgical and hydrodynamic performance of the machine. It will also illustrate the economic benefits derived by incorporating larger flotation cells in a modern copper sulphide concentrator.

Jan 1, 2007

Jan 1, 1968