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By Wen L. Cai

This paper examines the effects of different block dimensions and cone bases on the economic open pit limit design based on case studies on a coal deposit consisted of two west- east elongated, near vertical thin seams starting with a base model dimension of 200x170x50 (NX*NY*NZ) with a block dimension of 10mx5mx4m (DX*DY*DZ), the blocks were combined along easting, northing and elevation directions. Two cone bases were used, one with a base radius of 10 meters, the other with a base radius of 0. Two pit design algorithms, one is the floating cone algorithm, the other is an optimum algorithm, were used to see which one of the two pit design algorithms is more sensitive to block dimension and cone base variations. The results are presented and analyzed.

Jan 1, 1992

By John K. Hollmann

The use of the direct method of determining coal methane content has grown in the last decade from a research technique into a practical coal exploration tool. However, the literature available on the subject is somewhat lacking in site-specific guidance and observations on the conduct of the method and the use of the resulting data. This study discusses some practical lessons learned in conducting a large scale direct measurement project at an operating mine, describes the initia1 interpretations and uses of data from the project, and presents observations from subsequent mine operations into the success and limitations of using direct measurement data in mine planning. The site studied is in central Pennsylvania on the Appalachian Plateau and includes coal seams in the Allegheny series.

Jan 1, 1987

By A. Patton

E. T. McCLEARY, Youngstown, Ohio (written discussion).-Perhaps there is no question before the steel manufacturers of America today that causes them more worry than that of maximum production, together with good quality, and Messrs. Patton and Speller have clearly shown in their excellent paper how this may be accomplished. Any operation that tends to uniformity is certainly conducive to good practice, and as the use of roll scale in the converter eliminates to a large extent the variations in temperature due to varying silicon content in the pig iron, it should certainly give a more uniform product. At the plant of The Youngstown Sheet & Tube Co. the use of roll scale was started in the year 1908. A great many tests have been con-

Jan 4, 1917

By M. B. Ramachandra Rao

THIS paper records the results of the earth resistivity surveys made in the Godavari river in connection with the Ramapadasagar project. After describing the topographical and geological features of the area, the results of the investigation at the several sites have been mentioned. Further, a detailed account has been given of the resistivity methods adopted, the apparatus used and the interpretation of the curves. The resistivity measurements carried out over the water course have been specially outlined, and a review of the verification of the electrical indications by drilling in a number of cases, has also been presented.

Jan 1, 1947

Jan 1, 1905

By Waldemar Gooskov

IN his well-known work,1 published in 1867, P. Ritter von Rittinger gives the following formula for the velocity of a particle settling in still water: v=C/D(a -1) and for average grains he assigns to the constant C a value of 2.44. As is well known, the value of C depends on the shape of the grains resulting from crushing, and it is obvious that values obtained for coal particles will not only be very different from those for ore particles but will even be characteristic of coal from a certain seam. The only way of finding an accurate value of C, applicable to conditions in Russia, where all coal-washing plants are built on German principles, is to conduct a series of tests of which the results will determine what value of C is to be used. In the investigation outlined in this paper the theories of Prof. Robert H. Richards2 were taken as the basis of the tests; the slimes were removed from the charges to eliminate the trouble of handling them; and to obtain accurate results free from errors inevitably resulting from human observation, photographic apparatus was used and a series of pictures taken which form the basis for constructing a suitable diagram of velocity vs. time.3

Jan 1, 1928

Mr. John J. Porter, Chicago Ill. (communication to the Secretary†):—Mr. Baker's account of his experiences with stock-distribution has been particularly interesting to me, as it

Jan 1, 1905

By L. M. Johnson, C. G. Janes

INTRODUCTION In May, 1966, the General Services Administration (GSA) announced a program to encourage additional domestic production of copper in the interest of national security. Upon learning of the copper production expansion program, Duval Corporation entered into negotiations with GSA for development of the Sierrita copper-molybdenum property under the program. Agreements between the GSA and Duval Sierrita Corporation, a wholly owned subsidiary of Duval Corporation, were concluded in 1967, with the Sierrita Concentrator beginning operation in 1970 at a designed capacity of 72,000 STPD. Subsequent additions and modifications have expanded capacity to 90,000 STPD. This property, located approximately 20 miles south of Tucson, Arizona, represents an investment including working capital of about $200 million. These funds were provided from an $83 million loan from GSA, repayable in copper valued at 38 cents per pound, $48.75 million of bank loans subject to U. S. Government V-loan guarantees, and Company capital contributions. Current general operating statistics for the concentrator are listed below: [Ore Grade 0.32% Cu., 0.030"/. Mo. Daily Tons Milled 90,000 STPD Annual Copper Product ion 94,600 Tons Annual Molybdenum Production 15,000,000 Lbs. Annual Silver Production 1,135,000 Ounces]

Jan 1, 1976

By R. M. S. Falcon, L. M. Falcon

The prediction of the mechanical behaviour of South African coal on the basis of current proximate and other chemical parameters gives rise to problems, and the use of ultimate analyses and inferred maceral and rank analyses, although it has improved the situation to some extent, is still not satisfactory. In an attempt to reach a new level of understanding, this paper gives an in-depth review of the fundamental petrographic characteristics of coal and compares these parameters with the main types of mechanical performance. A two-tiered system of primary and secondary parameters is proposed for the prediction of coal behaviour. The primary or inherent parameters include rank and organic composition. The secondary or extraneous factors include such parameters as mineral mater, cracks or cleats, degree of oxidation, and size. In addition, an explanation is offered of several anomalous behavioural conditions in some South African coals.

Jan 1, 1987

By Joseph B. Darby, Paul A. Beck

IN isothermal sections of several ternary systems, the a-phase was found1 to extend in the form of a relatively narrow elongated field, connecting the U-phases that are present in the adjoining binary systems. This was interpreted in accordance with the conception that the U-phase is an electron compound and the ternary U-phase fields were shown in several systems' to extend approximately in the direction of constant average d-shell electron vacancy number per atom. ' However, in the various isothermal sections of the Fe-Cr-Mo system" the ternary a-phase field was

Jan 1, 1958

By T. J. Kim, S. Suh

The purpose of this paper is to evaluate overall prospects of the export market in the Pacific Rim for Illinois steam coal in terms of recent changes in global socioeconomic factors. To pursue this objective, three factors affecting the prospects of Illinois coal in the Asian market were selected for detailed analysis: quality requirements of imported coal, particularly those of the Japanese market; import controls and regulatory factors; and transportation factors affecting the export of Illinois coal. Based on these analyses, alternative long-term strategies are suggested for promoting Illinois coal export in the Asian market.

Jan 1, 1988

By John Fulton

The Connellsville coal-field is a separate strip of the upper coal measures, flanking the Chestnut Ridge along its western side. It extends from a point a few miles south of Uniontown, in Fayette County, following a northeasterly course parallel to the trend of Chestnut Ridge, through Fayette and Westmoreland counties, with its terminal prongs resting 011 the southern portion of Indiana County, north of the town of Blairsville. This belt of coking coal will average about three miles in width and over sixty miles in length, affording nearly, if not quite, two hundred square miles of this large coal-bed.

Jan 1, 1885

By Graham G. W. Mustoe

Energy losses are important factors in a conveyor's performance and design. A significant energy loss due to belt sag within a conveyor system occurs when shearing motion between the bulk material particles occurs as the material moves along the belt. An initial analysis of these phenomena was performed using the discrete element method, which is a general-purpose numerical modeling technique for analyzing the mechanical behavior of particulate materials. The software used in this work was Overland Conveyor Company's, Chute Analyst Professional, a discrete element computer code designed specifically for analyzing bulk materials transportation and handling problems.

Jan 1, 2008

By Brown DJ, Croghan JA, Denby B

The paper describes the development and analysis of an instability database to establish a new method of slope stability assessment for U.K. surface coal mines. The concept is based upon a Stability Index, which relates to the probability of failure of a slope. This forms the basis for a geotechnical planning software package to be incorporated into a computer aided mine design system , which is currently under development.

Jan 1, 1986

By Herle Rodríguez, Frank Astete

El modelo de “liderazgo por octógonos”, nace de la necesidad de generar una estrategia para visibilizar el liderazgo permanente en terreno de los líderes (caminatas gerenciales) y conocer el nivel de cumplimiento de los indicadores de seguridad y salud en cada una de las áreas. El ícono de los octógonos, tomo de referencia a los utilizados por el Ministerio de salud para identificar el riesgo a la salud de un producto, de la misma forma los octógonos (verde, amarillo y rojo) indican el nivel de cumplimiento e implementación del programa de seguridad y salud en cada una de las áreas. Esto logra un impacto visual por la relación al riesgo y la importancia en el cuidado de las personas.

Sep 29, 2023

By Benito Quiñones, Roger Asunción

En Newmont Yanacocha, la operación comprende tajos abiertos, pozas, pads de lixiviación, plantas de proceso y tratamiento de aguas acidas y de exceso. Un reto de sostenibilidad en Newmont Yanacocha es el control de la precipitación de metales preciosos en el proceso Merrill Crowe, por lo que fue necesario contar con una estrategia para cuando se tenga presencia de especies interferentes que pasiven el zinc en la precipitación, para ello se implementaron controles para mantener una eficiencia en el proceso y cumplir con los indicadores claves de desempeño.

Sep 29, 2023

MOWRY BATES, ? Tulsa, Okla.-In the first part of this paper the author says: "In an unpublished paper on Water Problem in the Augusta Field, S. K. Clark reaches the following conclusions: (1) That the great amount of water present is bottom water, occurring in the Varner sand, the main producing or the 2500-ft. horizon. (2) That the only striking connection between structure and water is in the area of the marked

Jan 4, 1919

By John F. Slonaker, Joseph W. Leonard

This note is a review of current research intended to increase the utilization of coal ash. Due to the magnitude of the fly-ash research program, some projects may be inadvertently omitted. Field research on fly-ash for use as an agricultural fertilizer is being monitored at Virginia Polytechnic Institute and State University. This research is directed at determining the plant nutrients that are available in fly ash as well as the quantities of fly ash that can be applied to agricultural soil.

Jan 1, 1975

By J. A. Finch, J. Yiantatos, A. R. Laplante

This paper re-examines the mixing conditions in the collection zone of flotation columns. These have in the past been characterized with a single uniaxial dispersion coefficient, E. The relationship between E and column diameter, Dc, is examined based on residence time distributions (RTDs) in columns of Dc ranging from 5.lcm to 184cm. Results agree with published correlations in chemical engineering, i.e. E a Dc '" , Data explain why pilot columns display significant upgrading between the feed level and the interface, whereas plant columns do not. It also suggests that, for plant columns, the full collection zone (up to the interface) can be considered when calculating the residence time. A mathematical model considering two regions of different mixing was compared to the single E model. Both models adequately fitted measured age distributions inside the column and overall RTDs. Measured and simulated mixing characteristics are compared to those of flotation banks, using a tanks-in-series approach; banks of comparable mixing to columns are identified.

Jan 1, 1988

By Dina Aloi

The need to be seen as responsible neighbours and good corporate citizens is a critical success criteria for mining companies. To be seen as responsible requires both achieving responsible performance, and making that good performance visible to the community, legislators, investors, and other stakeholders. This has broadened the skills required for the successful operation of a mining company to include social sciences, public affairs, communications, and environmental sciences. Mining companies still look to technical specialists to achieve the core of that good performance - broadly characterized as a sustainable operation. However, the degree of understanding that those specialists have of the requirements for sustainability and overall Corporate Social Responsibility has a tremendous impact on the overall performance of the project and company. In her keynote address to the Sustainability for Profit session, Dina will outline some of the key areas in which technical employees and consultants can contribute to achieving successful sustainable mining operations.

Jan 1, 2010