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The evaluation programme and procedures develop- ed for Saindak porphyry copper-gold-silver- molybdenum deposits located in an isolated area in an extremely and region of Baluchistan are described in detail. Due to its isol .ted location, far removed from supply centres, harsh climate, paucity of water and non-availability of even unskilled labour, Saindak presented problems for which no ready made solution exist- ed. It is hoped that this Paper may be of some value to those in the LDCs who may wish to undertake similar ventures.

Jan 1, 1988

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Jan 1, 1938

By A. C. Rand

The invention to be described in this paper is the work of Frederic A. Halsey, Engineer for the Rand Drill Company, of New York, and its use mill abridge the notable wastefulness of power of the striking rock-drill, and, at the same time, increase its capacity for work. That the older type of rock-drill is wasteful in power, is generally admitted; the cause being the use of steam* without expansion, arid the "cushion" of the blow, by the incoming steam upon the lower † end of the piston before the cutting tool strikes the rock.

Jan 1, 1885

By Mike McGill, Stephen Chung, Dale S. Preece

Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than normal is required plus an initiation technique designed to produce a much greater degree of horizontal muck movement. This is a significant change from normal blasting practice where fine fragmentation and sufficient muck movement were the prime requirements to permit efficient excavation.

Jan 1, 1994

By J. G. Peacey, P. Hancock, R. -Q. Li

A pyrometallurgical process for the direct recovery of zinc from zinc concentrates and zinc/iron residues has been proposed and tested extensively by Noranda. The process consists of smelting bone-dry zinc containing materials (sulfide concentrates and secondary zinc/iron materials) in a molten iron oxysulfide bath to volatilize metallic zinc into a SC^-free offgas. Sulfur contained in the feed materials is fixed as an iron oxysulfide matte for disposal. Thus, this process not only is capable of treating zinc sulfide concentrates and secondary zinc materials simultaneously, but also eliminates the need of sulfuric acid production. Detailed thermodynamic analysis and experimental test work are described in this paper.

Jan 1, 2000

By Ernesto Sirvas Bello

El presente texto señala el control geológico en la explotación de minas de oro. Dicha operación se divide en el control de las operaciones subterráneas y las de tajo abierto. Las primeras se relacionan con la explotación de estructuras vetiformes y las segundas con la mineralización diseminada de oro de “baja ley. Así también, se revisa las reservas porque se considera que en este aspecto ya no interviene el control de calidad, la cartografía, muestreo, dilución pérdida de oro por operación y los procesos de reconciliación de resultados. Finalmente, se muestran ejemplos de problemas que afectan el control de calidad y sus posibles soluciones.

Apr 26, 1999

By C. Ernest Birchenall

TWO recent papers1,2 cite measurements of surface contour changes on copper which, when attributed to surface self-diffusion, can be interpreted to yield activation energies for surface self-diffusion that approach1 or exceed2 those reported for volume self-diffusion in the same metal.3 It is acknowledged2 that AS must be assigned much too large a value to be physically reasonable in order to make the theoretical Do's agree with the experimental values, if the jump distance is of the order of the interatomic distance. However, long jumps would probably lead to marked anisotropy on planes that consist of ridges and valleys (like (110) in fcc) whereas only mild

Jan 1, 1963

By B M. Moudgil

Atomic force microscopy (AFM) has become an important tool for understanding the nano- to molecular scale mechanisms predominant in multiphase systems. In flotation research, the use of AFM holds promise for unlocking and establishing fundamental mechanisms, ultimately leading to significant advances in process performance. From measuring and characterising surface forces, the structure of molecules at interfaces, and nanoscale features on flotation media, AFM is a powerful tool that has only begun to impact flotation research. Highlights of advances made in the utilisation of AFM for flotation research at the University of Florida are given with an emphasis on interpreting the mechanisms behind calcium activation in phosphate flotation and the impact of nanoscale asperities on collector-born surface hydrophobicity.

Jan 1, 2005

By Roy Eric Lurie

Computer based signal processing techniques for obtaining empirical dynamic models from measured mill circuit data are discussed. This modelling is the first step towards designing a particle size control strategy. Experimental data from a computerized acquisition sys tern is examined and analysed, and a number of model identification procedures are applied. The resulting models are compared and a suitable model is selected, illustrating the benefits of computer tools for control system design.

Jan 1, 1992

By Keith Orgeron, Tibor Rozgonyi, Graham Mustoe, Vilem Petr

This paper presents the results of an experimental and numerical investigation of the shock wave energy transmission and reflection through boundary layers (joints, fractures) or between inhomogeneous geomedium with different physical properties. The conclusions drawn significantly clarify the dynamic failure mechanics because of shock wave energy transmission and reflection through different rock materials and their jointed interfaces. Thorough studies were performed to document the transient, two dimensional deformation characteristics, the normal and shear stress fields for inhomogeneous geomedium focusing on the influence of the internal geometrical shapes, relative density variations and packing of the grain boundaries.

Jan 1, 2002

By C. P. Davenport, Garth Duell

What are the projected electrical power needs of the nation and of the Northwest during the next 15-20 years? No one who has researched the subject has reached a substantially different result than the following simple conclusion: electrical power requirements are doubling every decade. There are some who question the necessity of a power company's need to install capacity every ten years equal to what it has done during its entire previous history; there are even those who would argue that such growth should be arbitrarily curtailed. However, a power company must, by law, meet its responsibilities of providing the energy the public expects when the switch is thrown.

Jan 10, 1972

By Monica Mengoli Chaves, Byron S. Gottfried

For the past several years the U. S. Department of Energy has sponsored the development of a computer simulation program that will predict the performance of coal preparation plants under a variety of different operating conditions. Recently a study was undertaken to transfer the simulation logic from the large scale mainframe environment to a small inexpensive microcomputer operating in a highly interactive "user friendly" environment. This paper describes a program that was written for the APPLE II Plus microcomputer which accomplishes these objectives. The program prompts the user for information in such a manner that it can be used by persons other than computer specialists. This makes the program directly accessible to plant managers, designers and operating engineers.

Jan 1, 1983

By Louis W. Cope

The Compañía El Zapote Yacimiento Y Minas, S.A. has an ore body containing 650,000 tons of 0.185 oz/t gold ore in Mexico. Metallurgical testwork has been done to determine the response of this ore to several possible processing schemes. The paper describes the rationale for selecting the Silver State Mining Co. methods in Colorado. Plans for developing the mine and building the treatment plant are described in detail in the paper. Estimates of capital and operating costs are included.

Jan 1, 1984

By J. M. de la Garza Cardenas

Mexico's total oil production in 1943 amounted to 35,149,843 bbl. and in 1944 to 38,196,818 bbl., both being substantially larger than in 1942, when production was only 34,71j1547 bbl. Daily average figures are as follows: 95,111 bbl. in 1942; 96,301, bbl. in 1943; and 104,363 bbl. in 1944. The increase of 8062 bbl. in daily output from 1943 to 1944 was due to more refinery Tuns and an expanded volume in exports of refined products, although the export of crude oil decreased somewhat. The increase affected mainly the southern Tampico district (Golden Lane), which in Deccmber

Jan 1, 1945

Reducing Fusion: The impure or low grade uranium concentrate is mixed with a formulated flux of sodium carbonate, salt, and sawdust or fuel oil and heated, while being stirred, to about 950°C. This reduces the uranium to the black, water insoluble uranium dioxide and with the exception of nonamphoteric metals forms water soluble sodium salts of the vanadium, alumina, silica, phosphates, and other constituents of the cake. The cooled melt is then water leached, leaving a residue of black insoluble uranium dioxide. "Green Sludge" Digestion and Liquor Purification: The green sludge is redissolved in acid, and by selective precipitation involving pH adjustments and a final neutralization

Jun 1, 1956

By S. Siddiqua

Diffusion is known to be the main transport mechanism of contaminants in fine-gained soils. To date, it is still common practice to estimate contaminant migration in the Bangkok Clay by means of pure advection models. A series of experiments with various chemical species was performed to determine transport parameters such as the diffusion coefficients and the distribution coefficients. The soil used was saturated undisturbed Soft Bangkok Clay. Column experiments were utilized in a number of laboratory tests involving advective-diffusive migration. Effective diffusion coefficients of different ions were back calculated from the test results. The distribution coefficients were determined from the results of the column tests and batch test. The results indicate that the evaluated parameters are in the range of values obtained from other researchers on similar kinds of soil. Based on this results contaminant migration by diffusion in the Soft Bangkok Clay can now be performed.

Jan 1, 2005

By M. F. Werneke, J. A. Jones

Abstract- The use of a unique class of sulfhydryl collectors, the monoalkyldithiocarbamate salts ([RNHCS]) as direct collectors for malachite and azurite is presented. Microflotation and laboratory scale flotation tests were performed to define the collector properties of these reagents under a variety of flotation conditions. On the basis of the results, it is proposed that some property of the amine-hydrogen atom in the reagent has a significant influence on the unusual activity of these collectors for oxide copper minerals.

Jan 1, 1978

By Robert E. Miller

Mass blasting of open stopes and pillars is a normal operating practice at Isa Mine. Three main parameters are used to classify the types of mass blasts. These are type of explosive used, blasthole diameter and system of initiation. Both electric and non-electric initiating systems are currently employed. The advantages gained by large firings are many. More efficient utilization of manpower, due to the concentrated and continuous charging, is achieved. There is no requirement for men to re-enter areas where localised ground conditions may have deteriorated and exposure of ringfirers to stope voids is reduced.

Jan 1, 1980

By Richard A. Arnold

The evolution of planning processes in the United States from the early 1900's is briefly examined. From one year operating budgets, planning processes have evolved into sophisticated analyses of alternative long-term future strategies and the management issues and practices which relate to their implementation. Increasing complexity within the business environment has led to numerous planning methodologies and extensive use of computers to analyze operating and financial information. All of these developments, however, have not supplanted the real need for decision-makers to continue to give important weight to the intuitive or soft data inputs into the planning process.

Jan 1, 1985

By P. Maraboutis

Extractive industry (mining and quarrying operations), as other industrial activities, is subject to environment protection laws, regulation and standards such as the Environmental Impact Assessment directive, Natura 2000, Habitats & Birds directive, Water Framework directive etc The European Commission (EC) is aim to strengthen the EU environmental legislation to improve the (environmental and human) safety of mining activities. The mineral processing and the management of the mining waste will be covered by the new amendment of the Seveso II Directive, by a Best Available Techniques reference document (BREF) describing the Best Available Techniques of mining waste management and a new directive on the mining waste management. At the same time initiatives as the environmental liability, the energy taxation for environmental reasons and the natural resources management policy, which will have a positive impact on the protection of the environment, will affect the extractive industry operation procedures.

Jan 1, 2002