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By Ronald Mamani, Russel Allidren, Diego Llanchipa

Esta investigación tuvo como objetivo evaluar la eficiencia del Sistema Tohá —conocido como Lombrifiltro o Biofiltro Dinámico y Aeróbico— para el mejoramiento de la calidad de aguas residuales domésticas. Para evaluar los parámetros DBO5 y DQO se tomaron como puntos de referencia aspectos biológicos del agua a tratar, que pasó a través de un biofiltro compuesto de 4 estratos (aserrín, grava, arena y carbón), el primero de los cuales incluyó lombrices rojas (Eissenia Foetida). Antes y después de realizar el filtrado se realizaron análisis de laboratorio. Como resultado respecto de remoción de contaminantes, se obtuvieron cifras que implicaban reducciones superiores al 50%.

Aug 31, 2019

By B. Xu

Keywords: Magnetic damping, g-jitter, Hot-film anemometry Results from an experimental study on natural convection induced by temperature gradient in molten gallium contained inside a rectangular container. The damping effect of the convective flow from an externally applied static magnetic field is investigated. Induced velocity and temperature fields are mapped using a standard constant temperature hot-film anemometry and a thermocouple with and without the applied magnetic field, respectively. Detailed experimental setup and procedure are depicted in the present paper. Obtained velocity and temperature profiles are examined against previous numerical simulations and reasonably good agreement has been achieved. Obvious damping effect can be observed in both the temperature and the velocity profiles when the external magnetic field presents.

Jan 1, 2005

By McAllister J

Oxygen was in restricted use at Port Kembla until tonnage oxygen became available for steelmaking in the open hearth furnaces. In adopting the new process various modifications to furnace design and operation were necessary and some of these, including increase in roof height and variation in firing and draft control, are discussed.The design of oxygen lances is also discussed and various steelmakingtechniques considered.Steel production increased with oxygen roof lancing-one- furnace producing 8,507 tons in one week-but new problems, such as rate of refractory wear, and disposal of fumes, were created.Design of future open hearth oxygen furnaces is predicted.INTRODUCTIONIn the post-war era, the availability of "tonnage" oxygen caused a major revolution in steelmaking techniques. Various pneumatic processes showed that steel can be madeat a very fast rate and that oxygen steelmaking can be applied to open hearth furnaces. Methods used are surface impingement with roof lances, bath injection with door lances, flame enrichment with fuel firing, mixed gas and oxygen firing, and enrichment of normal combustion air by oxygen injection into the flue systems.Owing to its previous restricted availability and high cost, oxygen was used in rather small quantities in the open hearth furnaces at Australian Iron and Steel Pty. Ltd.(A.I. & S.), Port Kembla, until about the middle of 1960.At that time tonnage oxygen became available and roof lancing commenced on No. 33 furnace at No. 2' open hearth shop.

Jan 1, 1962

By Fred Prime

To an association like the one before which I read this paper, few questions can be more important and constantly recurring than the following, viz.: "What economy can be effected in the manufacture of American iron ?" And it is the one with which I purpose to deal in this paper; premising, however, that my object is merely to indicate the direction in which an answer should be sought for, rather than to give it myself. This subject may be divided into two parts; " Economy in the production of pig-iron," and " Economy in the manufacture of wrought-iron;" but it is to the former alone that I shall confine myself this evening.

Jan 1, 1873

By Shin-Kun Ryi

The world nowadays faces many challenges associated with excessive utilization of fossil, fuels, such as poor air quality and greenhouse gas emissions. Hydrogen appears to be an attractive alternative to the conventional, fossil, fuels with better energy efficiency and less environmental, impact. Pd and Pd-based alloy are the most often used membranes for hydrogen separation due to their superiority over other membranes. However, the stability of the commonly-used thin Pd-based composite membranes at high temperatures still, remains a big challenge. In this presentation, we will, report our progress on thin Pd-Ru alloy composite membrane by electroless plating high temperature applications.

Jan 1, 2010

By Fred E. Wright

In a recent paper1 a detailed discussion is given of the possibilities of using polarized light in the examination of opaque substances. The factors underlying the problem are there treated from the viewpoint of the electromagnetic theory of light and the presentation is necessarily mathematical in form. The practical methods resulting from the discussion are, however, relatively simple and promise to be of value in the determination of certain ores and metals when studied in reflected light under the microscope. The results of the theoretical investigation referred to may be summarized by stating that in general the optical constants, such as refractive indices and absorption indices, cannot be satisfactorily ascertained on small, random, polished sections; that the use of polarized light enables the observer ordinarily to determine whether the crystal plate is iso-tropic or anisotropic, and also to ascertain the degree of anisotropism; that for this purpose methods based either on the contrast in intensity between the two reflected components of non-polarized light, or on the amount of rotation of the plane of polarization, on reflection, of vertically incident, plane-polarized light, may be employed; that methods based on the phase difference between the two reflected components are in general of little value because of the small differences in phase which ordinarily result for a relatively large change in birefringence or biabsorption. The measurement of the optical properties of transparent minerals, even in minute irregular grains, is a simple task with modern petrographic microscope methods and is accomplished by petrologists as part of their ordinary routine work. But the determination of the optical constants of opaque substances is difficult and is rarely attempted; all observations are necessarily made in reflected light and are restricted commonly to the determination of color, of hardness, of the character of crystallization, and of the behavior of the mineral or metal plate toward reagents and abrasives. With practice, the observer becomes expert in recognizing details of this kind and determines with a high degree of certainty the different

Jan 1, 1920

By Stanly A. Easton, H. M. Childs

Methods evolved at Kellogg have had primarily in view the safety of workmen and complete recovery of the ore; it is believed that these results have been secured at a minimum cost. The ore in the Bunker Hill mine is of good grade, relatively speaking; much of it is quite rich and no mining method would be successful which did not recover all of the ore. It would be possible to work certain of the orebodies by shrinkage methods, or some form of top-slicing, at probably lower costs than by the methods now applied, but the shapes of the orebodies are so irregular that satisfactory extraction of the ore in all its ramifications would be extremely difficult. In past years, much high-grade ore has been lost in blasting, due to the unskilful use of powder in a galena ore, which, by reason of its brittle-ness and great weight, tends to scatter widely. Any method by which large masses of ore and waste are broken together will result in an imperfect recovery of the ore, and whenever large masses are broken, ore and waste will unavoidably fall down together; ore and waste thus become entangled and, although a pile of broken material may seem to have been well picked over, quantities of ore will inevitably be lost. This fact has been shown by persons reworking the filling in stopes that were mined by methods defective in the foregoing particulars. Safety of the men is secured by avoiding large openings, and by working mainly under timber, and at small faces at close range and easily inspected. In former years the principal source of serious accidents was "falls of ground;" it is now over seven years since a serious accident has occurred from this cause. The most prolific source of accidents during recent years has been "timber and tools," workmen being struck by timbers passed into the stope from the level above; this danger has been greatly reduced by compressed-air warning whistles and the fencing in of dangerous areas. The lead-silver ore of the Bunker Hill and Sullivan and affiliated mines is found in bodies of almost every shape, although vertical or nearly

Jan 1, 1925

By Lee W. Saperstein

The SME Research Council assists SME and its constituencies in establishing research directions that will benefit the mining industry and its professions. It also provides information about these directions to its membership, to government and to related industrial societies. The 1995 Research Forum, organized and chaired by George Luxbacher, was the second in a series of meetings organized to develop these directions. A copy of the full proceedings is available from SME for $12 plus postage and handling. The first research forum (Saperstein, L., 1993, "Technology for the Future, MINING ENGINEERING, Vol. 45, No 11, November, pp. 1382-85) invited mining industry representatives to discuss the unsolved technical problems that were keeping the industry from greater economic and environmental efficiency. The second forum asked academic researchers to discuss the same general topics from their perspective. It came as no surprise that, in general, the two sets of presenters tackled the same problems. There was no surprise when the academics spoke of the need for fundamental long-term research. What may have been surprising was the number of university people who spoke for near-term research that leads to measurable economic returns or savings. The closure of the US Bureau of Mines (USBM) has changed the objectives and attitudes of the SME Research Council. From being a point of liaison between SME and USBM - a conduit of items from each party to the other the council is now much more on its own. This isolation presents opportunities and hazards. The opportunities are exciting because the council could be the focus for mineral industry research policy if it were properly structured. The hazard is obvious - if there is no bureau, it could be argued, why maintain the council? Many people believe that SME should take the first course and become the beacon for research policy. More than ever, money is being spent on minerals industry research by the federal and state governments - particularly at the mineral-oriented land-grant universities - by industry and by consortia among these groups. SME could be at the hub of these programs. There is a general concern that industry is less able to maintain an economic edge by means of geologic discovery. According to Titley, there will be fewer major, new world-class discoveries except, possibly, at the continental and tectonic-plate margins. Consequently, economic advantage will go to those companies and nations that stay ahead technologically. Given the inevitable diffusion of technology, it can be concluded that technology development, underpinned by research, must be continuous to maintain profits. This is a change from earlier years when change would occur in relatively rare major steps that were interspersed with extended periods of technological equilibrium. Over the fiscal years 1994 to 1997, there has been a 24% cut in research spending by the Department of the Interior (figures from the American Association for the Advancement of Science). This is the largest budgeted percentage cut in research funding of any federal department. Even so, there is still a substantial amount of federal research funding expended in the mineral and extractive-energy industries. The US Geological Survey, Environmental Protection Agency, Departments of Defense and Energy and others expend substantial funds on minerals industry research. Industry - producers and manufacturers - is also spending large sums on research and research-like activities. This activity argues that there is a role for SME's Research Council. Providing focus Consortia. The closure of USBM has resulted in the migration of expertise to consulting firms and to other entreprenrutisl research entities. Many of these groups are creating ad hoc consortia among themselves, nearby universities and industrial partners. The Research Council is well placed to provide an open forum for these con¬sortia. Presentations of research results, as went on in the annual meetings of the Generic Mineral Technology Centers, can help to establish an. archive of results and an avoidance of duplication of research. A continuing sense of research directions can evolve. National Science Foundation. No discussion of consortia would be complete without mention. of the National Science Foundation's (NSF) programs for Industry/University Cooperative Research Centers (IUCRC) and Grant Opportunities for Academic Liaison with Industry (GOALI). NSF is aware of the gap in federal support of science and technology caused by USBM's closure.

Jan 1, 1997

By Rolf S. Paine

The Bureau of Mines studied the presplitting technique used for control-ling overbreakage in the walls of a vertical shaft at the U.S. Army Corps of Engineers Littleville Dam project near Huntington, Mass. The periphery of the shaft, the dimensions of which were 16-1/2 feet wide by 21 feet long and 52 feet deep, was presplit (cracked) in the solid to a depth of 48 feet prior to full-depth sinking. Presplitting prevented overbreak in a fairly soft schist and provided sound self-supporting walls which required very little scaling.

Jan 1, 1965

By T. F. Mitchell, B. K. Shibler, J. V. Batty, W. G. Sandell, G. M. Potter

"INTRODUCTION The Park City district, situated 30 miles east of Salt Lake City, Utah, in the Wasatch Mountains, Is a well-known producer of lead, zinc, and precious metals. Nearly continuous production has been maintained from the dis¬trict since its early discovery about 1870. For approximately 50 years, gravity milling methods were employed to beneficiate Park City ore, and during that time tailings from the mills were sluiced down Silver Creek and deposited on lands below the camp for 7 miles.Owing to the large tonnage of tailings deposited along Silver Creek, considerable work was done in the past in the attempt to develop a low-cost concentration method for re-treating this material, but no-method was found that was economically feasible. The Bureau of Mines was asked to conduct beneficiation tests on Park City tailings in November 1944, and metallurgical studies were initiated at that time. This report summarizes the results of laboratory ore-dressing studies made on samples from the Grasselli deposit."

Dec 1, 1947

By D. P. Nicholson

The current phase of office development at Canary Wharf in the London Docklands includes twelve multi-storey buildings varying from eighteen to forty stories in height. The area of Canary Wharf South comprises five multi-storey buildings with low level in fill podium and garden areas. Three of these multi-storey buildings have "pile-cap" designs where the entire building load is applied to the piles. The remaining two buildings have "piled-raft" designs where allowance is made in the design for part of the building load to be transferred to the raft formation. Using a piled-raft design approach has enabled savings to be made on the number of piles used below the raft. This paper describes the calibration analysis undertaken to validate the design method. The ground conditions at the Canary Wharf site are typically fill and recent gravel deposits over the overconsolidated clay and sand of the Lambeth Group. Below these strata is the Thanet Sand. The Lambeth Group provided the founding layer for the raft and contributed to the pile shaft resistance. The Thanet Sand stratum provided the bearing layer for the 1.5m diameter base grouted bored piles. The piled-raft design required an assessment of the building load transfer through the raft to the formation layer. This load transfer led to significant increases in effective stress in the soil below the raft and thence a corresponding increased the capacity of the piles. This interaction of the raft with the prepared formation contributed to between 27% and 45% increase in total vertical load carrying capacity of the piled-raft substructure compared with the pile-cap design method. The development of the piled-raft design was carried out in three main phases: ? Development of the approach and validation analyses. ? Design work on various schemes resulting in detailed design packages. ? Validation analyses using full 3D finite element analysis (presented herein). The validation of the piled-raft design approach was initially carried out against published case histories for piled-raft interaction. To improve on the validation work a full 3D finite element analysis of a simplified pile raft and superstructure (which contributes stiffness to the raft) was undertaken; the analysis included only a quarter of the structure due to assumed symmetry of the structure and vertical loading. This 3D validation analysis is presented herein. The analysis was carried out using the Oasys LS-DYNA finite element program. Prior to carrying out the analysis of the piled-raft an initial finite element analysis was carried out to back analyse a fully instrumented field pile test providing accurate modelling of a single pile performance. This back analysis allowed confidence in the soil parameters used in the 3D model; comparisons of shaft and base resistances between the pile test and the FE model calculations for the single pile are presented. The parameters provided in this work were then carried into the full 3D model of the piled-raft. The 3D model of the piled-raft structure included 18 piles (12 full piles and 6 half piles on an axis of symmetry of the model).

Jan 1, 2002

By Jamal Rostami

With the recent technological advances; Tunnel Boring Machines (TBM) have become a viable economic alternative to drill and blast in hard rock excavation. These machines are finding increasing use in underground mine development due to the potential benefits they offer. The successful application of TBM technology to mining depends on the selection of the most suitable equipment and cutting tools for the rock and ground conditions to be encountered. In addition to required testing and geotechnical investigations, cutterhead design optimization is an integral part of the machine selection to assure a successful application of the machines in a specific project. This paper presents and discusses the back-ground of TBM application in a mining environment and the lessons learned, the process of conducting site investigation and the necessary laboratory testing together with machine selection and performance estimation for TBM use III mine development.

Jan 1, 1997

By Guillermo Philipps

El presente trabajo muestra la experiencia en estrategias de Optimización de minas subterráneas, basado en 40 años de experiencia en diversas operaciones en Perú y en el Mundo, con diversos ritmos de producción y siguiendo los siguientes principios fundamentales: Los principios de una buena administración: Planeamiento, Organización, Coordinación, Ejecución del Proyecto, Control, Liderazgo, Buen manejo de las relaciones interpersonales con los trabajadores, generar empatía, Cuidado del medio ambiente, entre otras.

Sep 1, 2017

By Victor Rakowsky

A CLEAR understanding of the factors that deter-mine the consumption of zinc metal is essential to a proper survey of the future of the industry and the relation of the several producing districts. With a view of explaining a sound basis for the consider-ation of some of the problems facing the zinc-mining industry of the Oklahoma-Kansas and Missouri district some of these factors are here set out. The zinc industry of the United States furnishes metal for three major uses, viz.: (1) zinking iron and steel (galvanizing); (2) brass making; (3) sheet rolling. Other important uses are for lead desilverization, the manufacture of castings, including die castings, and the manufacture of zinc oxide by the French process, which consists in burning spelter. The use of zinc for galvanizing comprises the coating of sheets, tubes, wire and shaped products, the latter ranging from chains to buckets. The brass-making industry may be sub-divided into manufacture of red brass, yellow brass and white brass, the percentage of zinc in these products being roughly 30, 40 and 80 respectively. The use of white brass is relatively a new thing and it may attain considerable proportions as a substitute for yellow brass. Ingalls estimated the percentage of total metal consumed for the above purposes in pre-war times as follows: HIGH PRODUCTION RECORD, SHORT TONS USES PERCENTAGE OF METAL Galvanizing 60-65 210,000 in 1912 Brass making 17-20 175,000 in 1916 Rolled sheets 10-12 57,000 in 1917 Other uses 5- 7

Jan 3, 1923

By Y. Mitsuda, Y. Kayanuma, T. H. Okabe, M. Miyake

A new process to recover platinum group metals (PGMs) from automotive catalyst scrap using metal vapor was developed. To improve the efficiency of the acid dissolution process of PGMs, metal vapor of reactive elements such as magnesium or calcium were contacted with spent automotive catalyst. It was expected that metal vapor would react with metal selectively and form intermetallic compounds. The specimen of the spent catalyst was treated at 1173 K for 3 h, and it was then dissolved in aqua regia for 1 h to recover PGMs. After the reactive metal treatment, 88% of Pt, 81% of Pd, and 72% of Rh in the catalyst scrap was dissolved, while only 77% of Pt, 69% of Pd, and 38% of Rh was dissolved from untreated scraps.

Jan 1, 2004

By Luis de Montreul

El presente texto señala algunos aspectos mineralógicos de la Cordillera Oriental del Perú. La Cordillera oriental se encuentra segmentada por profundos cáñones a través de los cuales se produce el drenaje hacia la Hoya Amazónica. Dicha entidad se desarolla hacia el este de los valles andinos, de forma paralela a la Cordillera Occidental. El dominio de la Cordillera Oriental es de mineralización polimetálica; pero, esta inmensa región del país es relativamente poco conocida desde el aspecto de su geología como de su metalogenia. De otro lado, se describe la faja aurífera de Pataz-Tayabamba, ubicación, geología general, económica, la mineralización del níquel en el Área de Huánuco, Tingo María, el área de Tarma Oxapampa-Ambo, el área de Vilcabamba, entre otras zonas.

Jan 1, 1981

By Galecki G

The investigations conducted in the High Pressure Lab at the University of Missouri-Rolla demonstrated the ability of high pressure waterjets to excavate coal and minerals, disintegrate materials and as well as to comminute coal and minerals. Additional progress in comminution can be achieved if the compressive crushing principle commonly used at present is changed to one where particles are fragmented by the tensile growth of preexisting internal flaws or cracks, under internal waterjet pressure. This idea was studied in a number of tests. It covers tests with different jets imposed on coal and rock samples during compressive load as well as without any loading.

Jan 1, 1993

By D Johnston

Within the first full year of BarrickÆs Cowal Gold Mine operation, the Lake Cowal Foundation Limited (LCF) has already been delivering results consistent with its goal to protect and enhance the natural environment of Lake Cowal and its catchment area. The LCF is a non-profit Environmental Trust established in June 2000 in conjunction with the development consent process for the construction of BarrickÆs Cowal Gold Mine. Its primary goal is to protect and enhance Lake Cowal, a nationally significant ephemeral wetland located 350 km west of Sydney, New South Wales, Australia. Significant concentrations of water birds visit the lake and the Australian Heritage Commission listed Lake Cowal on the Register of the National Estate in 1992. The LCF is managed by a Board of Directors from representative member organisations including the Total Environment Centre, National Parks Association, Nature Conservation Council and Barrick Australia Limited. Although largely funded by Barrick, the Foundation also attracts external funding and works in partnership with a diverse range of other groups and organisations, beyond the mine fence. The total value of currently approved projects is estimated to be in excess of $7.1 million, which includes æin-kindÆ contributions made by the local community and in particular the Lachlan Catchment Management Authority (LCMA) and local farmers. To date, LCF has been involved with the development and implementation of 30 projects with a total of 34 project partners. LCF has worked with over 60 landholders to improve Lake Cowal and its catchment, with 6180 ha of land now being managed for conservation or sustainable farming in the local area. Many landholders have been, or are involved in property planning or participating in other training opportunities. Sustainability of LCF programs and outcomes will be assured by commitments to projects within four key themes: conservation, research and research support, sustainable farming and community education and training. The LCF works independently from the mining company and has no responsibility for the environmental management within the mining lease. It is about capitalising resources generated by the mine to enhance environmental outcomes in the wider Lake Cowal catchment area by working collaboratively with the local community, industry and government authorities to ensure the long-term protection of a unique wetland ecosystem affected by landscape scale degradation.

Jan 1, 2007

By Fraser CJ

Stability control plays a prominent part in the planning and execution of coal winning in the deep open cuts in the Latrobe Valley operated by the State Electricity Commission of Victoria (SECV). Different stability mechanisms affect the individual overburden and coal faces. These are the classical rotational slip in overburden and the three-dimensional tetra- hedral wedge or planar block slip in the coal faces. The stability of the overall batters is affected by the so-called "block sliding" mechanism, which is unique in Australian open cuts. The basal stability of the open cuts is affected by pressure from water in confined aquifers underlying the coal being excavated. This paper describes each of these mechanisms and the current monitoring and con- trol techniques practised by the SECV.

Jan 1, 1982

By W. L. Penberthy, H. J. Ramey

Experimental work on the combustion oil recovery process has consisted of both laboratory and field studies. Although field experiments are the ultimate test of any oil recovery process, they are costly, time consuming and difficult to analyze quantitatively. Laboratory combustion tube experiments can be opertzted far more rapidly and cheaply, but are subject to scaling and interpretation problems. This paper points out some important design problems, operational criteria and considerations in2portunt to interpretation of results. An analytical hcut model of movement of a burning front axiully along a cylinder with heat loss through an annular insulation was developed. The result was used to identify steady-state temperatrrre distributions both ahead of and behind the burning front, with and without heat loss. Results indicate potential operating limitations on the minimum burning front rielocity (or air flux) which may be used for any given combustion tube. Results also enable estimating the effective thermal diffusivity and over-all heat loss from experimental data and thickness of the brnning zone. Resu lts of operation of a combustion tube constructed recently verify this preliminary theory in the region immediately ahead of and behind the burning front surprisinRly well. INTRODUCTION Many field and laboratory studies of the forward combustion oil recovery process have been conducted since the early publications of Kuhn and Kochl and Grant and Szasz2 in 1953 and 1954. In view of the complex and costly nature of this type of investigation, it is not surprising that no complete theory of the nature of the forward combustion Drocess is yet available. However, gross effects are understood well enough that reasonable design procedures are available for planning field operations. Nelson and McNeil 3,4 have published two comprehensive papers concerning design procedures. One major consideration in planning field operations is the fuel concentration at the burning front. Fuel concentration controls air requirements — an important cost factor in forward combustion. Although fuel concentration can be estimated from field test results by various methods, results are subject to great uncertainty in view of natural limitations on experimental observations. Nelson and hlcNeil4 recommend that fuel concentration be determined from laboratory combustion tube studies. Fuel concentration is only one of many important factors which can be studied by combustion tube experimentation. An obvious goal of imporrance must be development of a comprehensive theory of the forward combustion process. If a theory of this process can be established which matches controlled laboratory experimentation, it should be possible to apply this theory to field operating conditions with some confidence. Laboratory combustion tube studies have already yielded important information concerning the combustion process. However, details concerning the design, construction and operation of combustion tubes are rare. Combustion tubes used by various investigators vary in size, length and mode of operation. Therefore, one purpose of this paper is to present considerations important to design, construction and operation of a combustion tube. In regard to previous combustion tube studies, attention is called to Refs. 1 through 9. These references describe a wide variety of equipment types and present a great deal of pertinent experimental data. In general, combustion tubes usually consist of thin-walled stainless steel tubes containing an oil sand pack mounted within a pressure jacket. Provisions have often been made to heat the tube ex tern a lly by separately controlled heaters to reduce heat losses. This step usually permits operation at low air fluxes (air rate per square foot burning front surface) similar to those encountered in field operations. Burning is usually conducted from the air inlet end of the tube to the outflow end. The tube orientation used has been vertical or horizontal. For vertical tubes, burning has been conducted vertically downwards. As a result of laboratory studies, many of the

Jan 1, 1967