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By John Mathews

SOMEONE has divided mankind into two groups: (1) those who have the willingness and imagination to weigh the future gain over against a present indulgence, and (2) those who cannot do so. The former have self-control, patience, foresight and a capacity for sustained effort. Those having these homely virtues become the, possessors of capital and hence employers of others. Those lacking these qualities and owning no capital must seek it from those of the first class, and therefore are employed by others. The human qualities, which divide men into two classes-employers and employed-are, however, capable of change by education, training, environment and by all agencies which tend to develop character. These words of the economist have stuck in my mind for many years and the more I see of men in my business contacts the more firmly I am convinced of their truth. The earth in some respects resembles its inhabitants. When we stroll over the fields and hills we are impressed by the unorganized masses of sand and rock which make up the ground beneath our feet. When by chance we come upon a bit of mineral matter in crystalline form we are impressed by its beauty and symmetry and probably have it polished and call it a gem. Gems constitute a minute portion of the earth's crust, and those intellectual gems, worthy of polish, who brilliantly reflect the incident rays of education and experience that have fallen upon them are few among the masses of mankind.

Jan 1, 1931

By Robert W. Smith

The Bureau of Mines is engaged in a systematic evaluation of the thermodynamic properties of combustion gases. These studies are designed to provide basic thermodynamic information of high accuracy, facilitating the theoretical study of flame and combustion phenomena. This report is the fourth of a series4/ presenting results of the study for particular fuel-oxidant systems. These calculations have as their objective the evaluation of the constant pressure flame temperatures of methane-air, propane-air, and ethylene-air mixtures for a range of pressures.

Jan 1, 1953

By G. W. Birge, D. E. Wolfson, J. H. Lynch

This report presents all available 900 ° C BM- AGA carbonization and related data for coals from the principal beds of the southwest Virginia field in a form which permits ready comparison of product yields and properties of coals and cokes . Thirty- one channel samples from Buchanan , Dickenson , Russell , Tazewell , and Wise Counties were carbonized at 900 ° C in an 18 - inch - diameter retort . Blending properties of 10 of the coals were studied , and expansion of most of the coals and blends was measured in the Bureau of Mines sole - heated oven . Ash Most of the samples were chemically suitable for metallurgical use in coking blends , and their coking properties generally were satisfactory . content exceeded 10 percent in only three samples , and none of the coals contained more than 1.5 percent sulfur . Dry , mineral - matter - free fixed - carbon content of the coals ranged from 62.1 to 77.5 percent . Expansion behavior varied widely , ranging from 16.8 percent expansion to 27.6 percent contraction .

Jan 1, 1964

By Earl Oliver

SEVERAL notable papers, and free discussion on many controversial subjects, marked the various sessions of the Petroleum Division at the annual meeting. The Division first convened on Tuesday afternoon, Feb. 16, and wound up with a dinner and technical meeting on Thursday night. H. C. Fowler presided at the opening session, which was devoted to problems of engineering research and production engineering. Joseph Chalmers abstracted his paper on the flow of air and gas through porous media, in the preparation of which E. L Rawlins and D. B. Talia-ferro contributed. G. H. Fancher told how much he and his associates at Pennsylvania State College were interested in this field, and described the problems they had met in conducting test work. He made a plea for standardization of testing methods. Mr. Fowler then read an abstract of written discussion by Professor Barb, which was followed by discussion by Dr. Fancher and Mr. Chalmers of technical points in connection with the Chalmers' paper. H. H. Hill abstracted written discussion from Messrs. Wilde and Moore, of the Humble company. The second paper, by K. B. Nowels, on computing pressure drop in the pipe of flowing oil wells, was abstracted by the author. Messrs. Blair Smith, G. W. Coggeshall, and I. I. Gardescu participated in the discussion, and the chairman abstracted written discussion prepared by Mr. Rawlins. Most of this had to do with the viscosity of gas¬oil mixtures, on which subject Mr. Nowels said there was great need of accurate technical information.

Jan 1, 1932

By Larry M. Southwick

There have recently been executives at major metals companies who have recommended that Greenfield Projects not be pursued. Greenfield includes not only new geographical locations, but also new technologies and new types of feed materials. In the middle part of the 20th Century, two such projects were successfully commercialized to recover nickel from Cuban lateritic ores. One project (at Nicaro) used the Caron ammonia-ammonium carbonate leach and the other (at Moa Bay) a high pressure acid leach. How both of these projects dealt with these Greenfield issues will be reviewed, based on the original reports that described the research and development of the plants. This study will include a review of the critical ore characterization and sorting issues, as well as the extractive metallurgical, product recovery and equipment selection and sizing problems and how they were solved at each stage of project development, from laboratory through one or more pilot scale plants to start up and operation. In one case, a major revision of the plant was made after several years of operation to correct operating, equipment selection and materials of construction problems that hindered economical operation. These descriptions will provide a guide through the complicated and critical issues that in recent times have caused many companies to give up on similar development. Even with the more advanced analytical and computational tools available to today’s mineralogists, engineers and metallurgists, the basic concepts with which these projects successfully addressed their sets of problems are still required. In addition, upper management, now perhaps further removed from hands-on experience than was common then, will see how complicated problems require intense and detailed effort to avoid failure in the field and capital blowouts. Build it and we will make it run, kicking the can down the road and borrowing operating and design concepts incorrectly on technological issues, or nine year olds on a sugar high making financial decisions are not philosophies by which to succeed with Greenfield Projects.

Jan 1, 2014

By J-P Franzidis, P. O. Gyebi

"Coal-water mixtures (CWM) of concentrated fine coal may be transported in pipelines but this is influenced by both CWM rheology and stability. Here, a low viscosity is required to reduce power requirements, as well as good stability for transport and storage. The objectives of this study are to investigate the importance of surface charge, solids concentration and dispersant addition on the rheology and stability of a fine Witbank coal-water mixture (<75 m). Zeta potential, rheology and stability were measured with a Malvern Zetasizer, a AR1500EA rheometer and a static rod penetration test, respectively. Sendep 30D, Sendep 30F and Norilose 8058, all supplied by Senmin International, were used as dispersants, at dosages of between 0.1 to 0.5% dry coal (w/w). Solids concentration was varied from 10 to 58% (w/w). The zeta potential was found to be positive at low pH and decreased sharply with increasing pH to a minimum of -50 mV at pH 10. The zeta potential decreased with increasing dispersant concentration for all dispersants. The lowest zeta potential of -63 mV was obtained for Norilose 8058 at a dosage of 0.3%. CWM rheology was Newtonian at lower solids concentrations but became non-Newtonian at solids concentrations over 40% (w/w), with an initial yield stress and pseudo plastic behavior. The yield stress decreased sharply with increasing dispersant concentration for all dispersants. The lowest yield stress was obtained for Norilose 8058. The addition of dispersants resulted in significant improvements in stability. A penetration ratio of over 70% was obtained for Norilose 8058 after 10 days. In summary, the addition of dispersants resulted in a decrease in the zeta potential which increased the electrostatic repulsive forces between particles, thus improving both CWM rheology and static stability.INTRODUCTION Coal Water Mixtures South Africa’s energy economy depends heavily on coal. It accounts for about 70% of primary energy consumption, 93% of electricity generation and 30% of liquid petroleum fuels (Eberhard, 2011). The transportation of coal to export markets and power generation stations is a problem in the South African coal industry due to ageing and inefficient rail infrastructure. This problem is intensified by the long distance of coal haulage, delays in the time required to load and unload wagons, and environmental challenges related to air pollution and water contamination. Fine coal may be transported more efficiently and economically in a pipeline as a highly concentrated coal water mixture (CWM). Typically a fine coal CWM will contain 60-75% coal, 25-40% water and nearly 1% of dispersing additives (Atesok et al., 2005; Dincer et al., 2003). However, the transport of CWMs in pipelines is strongly influenced by both CWM rheology and stability. Here, a low viscosity is required to reduce power requirements, as well as good stability for transport and storage. These quantities are affected by the coal composition/mineralogy, solids concentration, particle size and size distribution, particle shape, inter-particle forces and dispersant type and dosage (Laskowski, 2001)."

Jan 1, 2018

By D. E. Wolfson

The Bureau of Mines carbonized 35 coal samples from Logan and Mingo Counties) W. Va., at 900° C using the Bureau of Mines-American Gas Association method, and determined yields of products and physical properties of cokes. Twenty samples represented the No.5 Block, Stockton, Chilton, Cedar Grove, Lower Cedar Grove, Alma, No. 2 Gas, and Eagle beds in Logan County, and 15 samples represented the Coalburg, Buffalo Creek, Winifrede, Cedar Grove, Lower Cedar Grove, Alma, and No.2 Gas beds in Mingo County, W. Va, Chemical analyses were determined for all coals. All coals in both counties rank as high-volatile A bituminous. Most of the coals are chemically suitable for metallurgical coals. Coals with accept-able ash and sulfur contents can be used as major constituents in coking blends with higher rank coal to yield coke with satisfactory properties for blast furnace use.

Jan 1, 1967

By A. W. Ambrose

"A need exists for men in oil-field production work who correspond to the mining engineer of a large mining property. Some oil companies prefer to call such an employee a resident geologist, resident engineer, or a petroleum technologist. He should perhaps be more correctly termed a petroleum production engineer. The duty of such a man is to apply his scientific and geologic training practically to oil-field development work.He should be, by education, a mining, civil, or mechanical engineer, with a knowledge of geology and chemistry. Upon completion of his education, such a man should spend several years in the oil-fields. There are two means of gaining proper experience. The first method is to work for an oil company in making a detailed study of each well, collecting data on the history and production, followed by a preparation of good records, from which well logs can be prepared. From the well logs, the geologic cross-sections, peg-models, and structure contour maps can be made. These allow a comparable, detailed study of each well, which is necessary to solve many of the problems. Along with this the engineer should visit drilling wells daily for collection of samples of formations and for a proper study of how they drill. He should form friendly relations with the drillers and production foremen. The second method of gaining proper experience is to start work as a roustabout, pumper, or on the pipe¬line gang, finally working up to a tool-dresser. After three or four years of such work, the engineer may be classed as a petroleum production engineer."

Jan 1, 1920

By William Breeding

El objetivo del presente texto es explicar y comparar las técnicas más útiles y económicas para la explotación de veneros. La técnica más económica para la explotación de veneros es el uso de la draga de cangilones o "bucketline dredge", es decir, una draga con cadena continua de cucharas. En ese sentido, las dragas hidráulicas con cortadores de estilo canasta y dragas con cuchara de estilo almeja han sido probadas en varios lugares durante muchos años para satisfacer condiciones especiales, aunque han sido menos satisfactorias que las de cangilones.

Jan 1, 1978

By Charles D. Litton

An overview of state-of-the-art technology in fire detectors is presented by the Bureau of Mines regarding their use in the mining industry. Detectors are categorized according to the characteristics of a fire to which they respond. Operating principles of the various detectors, their application, and the advantages and disadvantages of each are discussed.

Jan 1, 1979

By W. M. G. Heeley

In the province of Alberta the coal measures dip at so many different angles, between the horizontal and the vertical, that many different systems of haulage are in use. I will, however, only touch briefly upon the general -systems in use, and devote the major portion of this paper to a discussion of endless-rope haulage and its adaptibility to various conditions in coal mines; dealing in particular with the endless-rope haulage that was installed at Brule during the month of August 1923. In coal seams that are approximately level, and newly opened, hand-putting or tramming from the face is the cheapest, but when the mine is further developed tramming is out of the question, and the use of ponies is the next consideration. The time arrives, however, when mining reaches a point where the economical haulage of coal by horses cannot be done profitably, and then some system of mechanical haulage must be installed. The installation of any system should be carefully considered before any particular type of haulage is adopted, because a great deal depends upon the grade or dip of the seam. Motor haulage is impossible to operate profitably on a grade of over 6 per cent and, while it is possible to use ponies, on short runs, up to 9 per cent, some other means of main and secondary haulage must be installed when a 9 per cent grade, is exceeded. I will, therefore, deal first with secondary haulage, because even though a main haulage is established, secondary haulage can be used to feed the main haulage.

Jan 1, 1925

By Susanna G. de Jager, Francis W. Petersen

"The aim of the project was to develop a methodology applicable to different South African coal types to be able to predict with a high degree of certainty what kind of reagent will be suitable for flotation of a certain coal type.The study included 5 coal samples from different collieries and included Highveld seam 3 and 4 coal (as one sample), Waterberg coal (zone 10 -11), Highveld seam 5 upper coal and Witbank seam 2 and seam 4 coal. Seam 3 and 4 (mixture) coal, Waterberg and the seam 5 upper coal were all found to be vitrinite rich coals. The coal characterisation study included petrographic analysis, proximate analysis, float-sink analysis, oxygen-containing functional groups, surface extraction, flotation release analysis and contact angle measurements.The flotation tests showed that the best reagents to float all of the coal samples studied are iso-decanol and dodecene. These reagents produced flotation products that are near to the release curve. Statistical relationship for predicting ash content and yield that can be expected for a certain coal type and selected collector was obtained. From the relationship, the accuracy of the yield is above 95% (p-value below 0.05) with a linear regression of 0.9289. The accuracy of the ash is slightly lower with a linear regression of 0.7841 but also above 95%."

Jan 1, 2003

By Heramb M. Bal

This paper will underpin the future development of intellectuals having greater understanding of patent law and legislation, IP rights, and innovation. To understand this idea, I present a case study of China?s progress in the last 31 years in the rare earth research, innovation, and simultaneously patents area. Rare earth elements (REE) are at the centre of high technology and are the next wave of world innovation. Much of modern society depends on rare earth elements through their use in computers, lasers, telecommunications, iPods, medical technology, military applications, and so on (Long et al, 2010). The rare earth research, a large research body is being provided by Chinese sources. China devoted three or four university centers to the study of rare earths (Lifton, 2009). These measures are all designed to keep China at the forefront of REE production, materials, technology, and innovation. As a result in the last fifteen years there has been a shift from a US-dominated REE industry patents to Chinese patents. The world must identify strategic areas of rare earth innovation and provide funding to firms and universities that conduct such research. Not only research and innovation is vital but filing patents and preserving IP rights for research and innovation is even more important. We (rest of the world) need a comprehensive strategy to guide the development of patent and IP rights for research and innovation. To achieve this, the development of intellectuals with superior knowledge of patents and IP rights are the future need of minerals industry. Keywords: innovation, rare earth, patent, IP rights

Sep 1, 2012

By N. Melnyk

IN the past, the Cadomin Coal Company has opened four mines, all in the same coal seam or its folds. Three of these were opened from river level by horizontal entries or rock tunnels, and the fourth, the present working mine, by vertical shafts. This paper deals largely with some operating phases of this fourth mine, with which the writer has been associated. The seam worked here is a thick, steep, bituminous seam, and the writer feels there is a paucity of published data on the mining of such seams. Possible reasons for this are that such seams do not !end themselves to intensive development or mining, there is little chance to mechanize because of the extreme pitch, and operations are fraught with many problems. In addition, the present operations in this particular seam are being carried on at a level below the former workings, introducing new problems, not en-countered on the upper level. Coal will, without question, long continue to be an important factor in the national economy, and some of the best coal is to be found in thick, steep seams. But with the exhaustion of the easily-mined coal near the outcrops, future coal will have to come more and more from lower levels. At Cadomin there is still considerable coal on the second level, below the old river-workings, and there is a possibility that, in the future, still lower levels will be worked. It is the purpose of this paper to indicate some phases of such lower-level operations and to invite discussion.

Jan 1, 1942

By J. M. Hollicky

The economical processing of wet and sour natural gas presents a problem due to the seasonal demand for natural gas. The plants must be sized to handle the peak loads but may only operate at half capacity on the average, in which case the sales value of sulphur and hydro-carbon liquid by-products cannot support the operating and capital costs of the plant. This must result in an increased price for the gas. This problem was solved by Pacific Petroleums and Westcoast Transmission in the design of their pipeline and plant facilities now operating in the Peace River area, where there are both wet and dry gas fields. By .building a plant to process sufficient wet gas to pro-vide the base load requirement, and by drawing on the dry gas fields for peak loads, an optimum economic operation was ?possible. The sulphur, L.P.G., and gasoline produced not only are able to support the operating and capital costs of the pro-cessing plant, but were instrumental in the sharp drop in retail prices of these commodities in the area. The sour gas and condensate is gathered from the fields in the area and transmitted in a two-phase gathering system to the gas processing plant at Taylor, B.C. The condenrnte is knocked out in inlet scrubbers. Hydrogen sulphide and carbon dioxide are removed in an amine scrubbing unit. The hydrogen sulphide is stripped from the amine and is sent to the Jefferson Lake Sulphur Company&apos;s plant which produces sulphur by the partial oxidation of the hydrogen sulphide. The natural gas, now sweet, is processed in an absorption unit to recover additional liquids, before being de-hydrated to remove water. It is then sent to Westcoast&apos;s main c8mpression station. The condensate recovered in the inlet scrubbers and the liquid re-covered in the absorption unit are fractionated to remove fuel gas, used in the plant, and to produce pro-pane, butane, and naphtha. The pro-pane and butane are scrubbed with caustic soda to remove hydrogen sulphide. The naphtha is treated with hydrogen in a unifiner unit to re-move sulphur compounds completely, and is split into a light and heavy naphtha. The heavy naphtha is .catalytically reformed to produce a high-octane blending-component. These fractions are blended with components produced from crude oil at the Dawson Creek refinery to produce a high-quality balanced gasoline with special attention being paid to volatility for ease of starting, warm up, and engine cleanliness, and octane for power and ?performance.

Jan 1, 1958

By T. T. Read

"Education is the one thing which is unanimously regarded as valuable. The growing complexity of modern life, with its intricate organization, the manifold kinds of mechanical equipment that are used, and the constantly growing, necessity for the speedy and accurate interchange of information and ideas, make education an asset that constantly increases in value. The number of things that may profitably be known has grown so large that the field of education has been divided, and attention is often directed to only those things that are most immediately valuable. Modern educational facilities are often directed to what may be called corrective, work; the, providing of people with information that they teed in the conduct of their daily lives, but which for various reasons they have not previously had facilities for acquiring. The value of special education in the industrial world has been so thoroughly demonstrated that far-seeing managers of mining enterprises are always interested in the educational facilities existing in the community where their work is carried on.The educational facilities of a modern community may be classified in several ways. They may be divided into;1. Facilities for general education, for the purpose of increasing the whole field of knowledge of the student.2. Facilities for special education, which are intended to remedy a specific defect, or to give proficiency in some special field. This may be divided as follows;a. Training for work, intended to fit an employee to adequately perform the task assigned to him, this ranges from brief instruction by a foreman or fellow-worker up to definite training courses in which the employee dose nothing but study for a period of several weeks or months, being paid during this period a wage that may range from a nominal amount up to practically full time salary. The student's educational preparation may already be fairly advanced. Some of the manufacturers of electric machinery maintain, a school similar to that just described for graduates of engineering colleges. In other cases the only pre-requisite may be a common school education, as in the schools for operators, maintained by the telephone companies."

Apr 1, 1920

By Harold M. Feder, Robert V. Schablaske, Irving Johnson, Ewald Veleckis

The stoichiometry, structure, and stability of the internzediate phases formed between zinc and some of the rare earth (RE) metals were systematically exarnined by means of a recording effusion balance and X-ray diffraction analyses. In the La-, Ce-, PY-, Nd-, and Y-Zu systems, at or below about 600 C, the following sequences of phases (REZnx) were found: La, x = 1, 2, 4.0, 5.25, 7.3, 17/2, 11, and 13.0;&apos; Ce, x = 1, 2, 3, 11/3, 4.3, 5.25, 7.0, 17/2,* and 11; Pr,x = 1,2, 3, 11/3 ,* 4.3, 5.3(?), 7.0, 17/2,* and 11; Nd,x = 1,2, 3,* 11/3,* 4.3, 6.5, 8.5,* and 11; Y,x = 1,2,3, 11/3, 4.5, 5.0, 17/2,* and 12.* The structure types of all these phases were classified. In addition, lattice parameters were obtained for the first time for the pluses denoted by asterisks. In the absence of de tectable valency or electronegativity effects the systesnatic trends in the results have been ascribed to the effects of&apos; the lanthanide contraction. For example, the maximum number of zinc atoms in the coordination polyhedron surrounding the RE atom decreases from twenty-four to twenty-two to twenty as the size of the RE atom decreases. THE structures and compositions of a great many intermetallic phases (e.g., the Laves phases) are known to be based primarily, but not exclusively, on the space-filling efficiency of various modes of packing together atoms of different sizes. The valencies and electronegativities of the constituent atoms are, however, also influential. In extreme cases hypothetical intermetallic phases which fulfill the efficient spacefilling requirements may not be present in the constitutional diagram because of thermodynamic instability brought about by the operation of valency or electronegativity factors. Hence, for a detailed study of the influence of atomic size on alloy structure and composition, it would be desirable to minimize variations of valency and electronegativity. The intermetallic phases formed by the rave earths (RE) with some common partner offer an excellent opportunity for isolating the effects of size from those of valency and electronegativity. The rare earths exhibit a large, but smooth, decrease in size (the lanthanide contraction) in the series from lanthanum to lutetium when inter comparison is made for a common valence state, e.g., isolated atoms or trivalent ions. The elements yttrium and scandium are frequently included as pseudo rare earths; their sizes place them in the vicinity of dysprosium and lutetium, respectively. The electronegativities of RE elements vary by less than 10 pet. The trivalent state is the most common; however, the well-known tendency of cerium, praseodymium, and terbium to achieve higher valencies, and of samarium, europium, and ytterbium to seek lower valencies, requires that caution be exercised in the assumption of equal valencies. In the present study the existence, constitution, and structure of each of the numerous intermediate phases formed by zinc with lanthanum, cerium, praseodymium, neodymium, or yttrium were examined systematically and in detail. The investigation was conducted by a recording effusion balance technique and by X-ray diffraction analysis. The results enrich our knowledge of the phase diagrams of these systems. In addition, they present some clear-cut evidences of the operation of the size factor alone. EXPERIMENTAL PROCEDURE Apparatus. The mode of operation of the recording effusion balance and its application to phase studies have been discussed in detail elsewhere.&apos; In this work, an effusion cell containing a finely divided alloy was suspended within an evacuated tube from the beam of an analytical balance. The tube was immersed in a massive molten salt bath whose temperature was controlled to within 0.5o C during each experiment. The loss in weight of the alloy owing to effusion of zinc* was continuously recorded. Two effusion cells, 1/2 in. diam by 1 in. high, were machined from tantalum rods. Two orifices were drilled laterally into the walls of each cell. The orifice areas were determined by calibration with pure zinc: cell A had a total orifice area of 6.5 x 10-41 sq cm, and cell B an orifice area of 9.8 x 10-3 sq cm. By appropriate choices of orifice area and temperature the wide range of volatilities from pure zinc to pure rare earth metal could be investigated. X-ray diffraction powder photographs were made at room temperature with a 114.6-mm Debye-Scherrer camera with both filtered CuKa radiation and filtered CrKa radiation. Lattice parameters were refined by a computer-programmed least-squares analytical treatment which incorporated appropriate extrapolation techniques.2 Frequent use was also made of a special computer program3 designed to generate a powder pattern from an assumed structure in order to verify structural assignments. Materials. Lanthanum, neodymium, and yttrium were purchased from the Lunex Co., cerium from the Cerium Metals Corp., and praseodymium from the St.

Jan 1, 1968

By Mayworm Luiz, Mantovanelli Mauro, Merisio Everaldo, Oliveira Edgar Adrian, Vieira Estéfano Aparecido, Kaneda Kazuyuki

Os filtros da estação de tratamento de água do circuito spray da planta de lingotamento contínuo apresentam problemas de desempenho quanto a vazão, gerando perda de produtividade do processo de produção de placas da ArcelorMittal Tubarão. Na etapa de filtração da água de recirculação utilizada no circuito de spray, ocorre redução da vazão com o tempo de operação não atendo a necessidade do processo. Existe uma divergência de especificação de projeto uma vez que o projeto original visa tratamento de água potável e não água do sistema direto de lingotamento, uma água com alta concentração de sólidos em suspenção e óleos&graxas. Para recuperar a vazão da água filtrada, é necessário aumentar a frequência de contra lavagem, melhorando a passagem da água e limpando os leitos, porém a alta frequência de contra lavagem torna-se uma complicação para operação da ETA, não garantindo a estabilidade da operação. O objetivo deste trabalho foi identificar e propor soluções para os problemas de vazão dos filtros de forma a garantir a especificação nominal de projeto (1380 m³/h / 5 filtros) e consequente estabilidade operacional do sistema. Foram feitas avaliações em laboratório para identificar a composição ideal do leito filtrante assim como sua distribuição granulométrica, além de modificações internas do filtro e das crepinas utilizadas no sistema de contra lavagem. Após as modificações, o filtro está operando por quase um ano conforme especificação, garantindo a vazão de filtração e prolongando o tempo de contra lavagem de 6/6 horas para 15/15 horas.

Oct 1, 2019

By Angel Mamani, Marcel Hürlimann

El deslizamiento superficial de tipo traslacional se encuentra al lado del pueblo Cercs, que pertenece a la región Berguedà de Cataluña; este deslizamiento tiene volumen aproximado de 250 m3, 12° de pendiente y la superficie de rotura se sitúa a 0.6 m de profundidad en roca altamente meteorizada. La caracterización geológica se realizó mediante mapeo superficial y tres sondajes manuales, las cuales permitieron identificar tres estratos; coluvial, argilita alterada y argilita inalterada; la superficie de falla del deslizamiento se ubica en estrato de argilita alterada. También, se efectúo la caracterización geotécnica mediante ensayos de laboratorio, donde se realizó 10 análisis granulométrico y límites de Atterberg, 3 ensayos de permeabilidad por carga variable, 5 ensayos de corte directo y 1 corte anular.

Sep 30, 2022

By Jorgen Elbrond

In a stream of ore in an underground mine or in a beneficiation plant bins are installed between machines or machine system. When the upstream machine is stopped the downstream machine can continue operation for a while and vice versa. The paper describes a procedure for calculating the total capacity of a system consisting of two machines with an intermediary bin as a function of the bin&apos;s live volume and of the installed machine capacities and their production variations, which are defined. Extensions to several machines in parallel and in series are shown as well as practical examples.

Jan 1, 1982