Search Documents

By Enrique Monge

El presente artículo describe la importancia del acero en Estados Unidos de Norteamérica como el más grande productor de acero del mundo. Los principales minerales utilizados son los óxidos de hierro como la hematita, jimonita y magnetita. El mineral de fierro es extraído por el método de tajeo abierto, palas mecánicas separan la cubierta de detritus y cargan el mineral directamente a camiones o carros de ferrocarril. En Alabama y a lo largo de los Montes Apalaches existen depósitos de fierro sedimentario de formación más reciente que los del Lago Superior, produciendo cerca de 6% de la producción total de los Estados Unidos en 1963. Otros tipos de minerales de fierro explotados en los Estados Unidos son las magnetitas de New York, New Jersey, Pennsylvania y las magnetitas y hematitas de Missouri, Utah, Wyoming y California.

Nov 1, 1957

By Felipe Poffo, Flávio Messas

Due to the high level of competition in tooling sector, a necessity to increase the level of processes and assets management has initiated. Based on the World Class Manufacturing methodology, applied mainly in serial production industries, we have challenged ourselves to adapt the main concepts and implement them in a tooling company. After one work year, we could notice 29% productivity improvement in the bottleneck process, 25% cost reduction in outsourcing, standardization of the processes, 8% reduction in direct labor. Consequently, it was possible to implement a financial reserve and a long term planning cash flow.

Nov 22, 2018

By L. E. Djingheuzian

"IntroductionDURING the past two decades an enormous amount of empirical data has been accumulating on grinding. These data have been obtained by mill operators on grinding ores with a diversity of characteristics, and generally they have been published. However, whenever an operator, who has started milling on a new ore, has tried to find a case in literature which would exactly fit his particular grinding problem, he has failed. Evidently, something fundamental has been lacking in all these empirical data, and, as a consequence, each new operator has had to undertake his own experimenting, get the best results he can, maybe publish these results, and let it go at that. This, in the writer's opinion, has been• due to the fact that even the ablest and most inquisitive millman has been forced to look on grinding as an art, and so, except very rarely, has not been able to find the time to stop and think; if he did so, it was rather in a philosophic way, that grinding is a fundamental process, a process that takes place in river beds, on the sea shore, etc.Nevertheless, when all the data so far published are correlated and examined as a whole, one is struck with the advances that have been made in grinding. The writer (7) had made such a study in 1949, and, when the correlation was completed, it showed that there was nothing heterogeneous about the accumulated data and that when brought together they were in harmony with each other. The writer's conclusion was that, if grinding criteria were defined and were expressed in such a way as to make integration of any data into basic formulae possible, grinding would be established as a mathematically exact science, and grinding worries of the harassed mill operator would be at an end!The first attempts to rationalize comminution were made by Rittinger and Kick. However, their theories led to endless disputes which did not accomplish much, except possibly clearing the path for subsequent investigators."

Jan 1, 1952

By Georgc E. Collins

SEVERAL years ago, I estimated the total stock of gold in the world to be about a thousand million ounces, of which rather over one-third was available for monetary uses. Robert H. Ridgway has estimated the world's production from 1493 to 1927 as slightly over this amount. Of this total, 1.5 per cent was produced between 1493 and 1850 (before the Californian and Australian goldfields began to flood the world with gold), 331/2 per cent from 1851 to 1900, and 511/2 per cent from 1900 to 1927. Allowing for loss by attrition and permanent consumption in the arts, and for loss of buried treas¬ure, my first-mentioned estimate is perhaps not far from the truth; but my estimate of the monetary stock was certainly too low. Of the total production stated by Rid-way. 28 per cent came from North America. 26.9 per cent from Africa, 1.6.8 per cent from Australasia, 12.4 per cent from South America, and 11.2 per cent from Asia. Excepting that from the African conglomerate beds, the ultimate origin of which is still the subject of controversy, by far the greater part of the total production was derived from alluvials. Weighing all contingencies, it is improbable that any such production as has been made during the last forty years will be repeated in any similar period, if the present price level is maintained. The gold standard today seems firmly established except for temporary digressions. Nevertheless, no well-informed mining engineer will venture to assert the probability that the material for its maintenance throughout future generations can be furnished.

Jan 1, 1932

By W. R. Reed, G. W. Luxbacher

Mine worker exposure to respirable coal dust and silica dust can result in coal workers’ pneumoconiosis and silicosis which are occupational respiratory diseases that have no cure and are ultimately fatal. In 2021 the Mine Safety and Health Administration reported just over 11,000 operating metal/nonmetal mines with the potential for silica dust exposure for just under 200,000 miners. The National Institute for Occupational Safety and Health (NIOSH) conducts respirable coal and silica dust research associated with mining through its Office of Mine Safety and Health Research. NIOSH respirable coal and silica dust research began under the U.S. Bureau of Mines (USBM), which initially examined silica dust, progressing to include coal dust, with a stronger focus after 1969 with the passage of the Federal Coal Mine Health and Safety Act. A review of extramural research to develop real-time respirable silica dust monitor is presented along with a brief history of silica dust regulation.

Feb 1, 2024

By J. C. Mitcheson

Mr. President, Mr. Mayor, Ladies & Gentlemen: IT GIVES ME great pleasure to have the opportunity, today, to speak on behalf of all the constituent. bodies of the Common-wealth Council of Mining and Metallurgical Institutions. For the past month we delegates have been right royally entertained across the length and breadth of Canada by Provincial Governments, City Councils, and other equally generous public organizations and private corporations. On this occasion, however, the President of The Canadian Institute of Mining and Metallurgy, our good friend Dr. H. J. Fraser, has been our host at the enjoyable reception preceding this Institute Luncheon, which luncheon was sponsored by our official host, The Canadian Institute of Mining and Metallurgy, one of our .constituent bodies.

Jan 1, 1957

By Rafael Ramos, Leonel Quispe, César Chávez

El programa de trabajo de campo realizado consistió principalmente en el cartografiado de la concesión minera EMADSUR I y el muestreo de estructuras (vetas y cuerpos). Los resultados preliminares del estudio geológico en el proyecto Livitaca confirmaron la presencia de mineralización tipo skarn y tipo pórfido de Cu-Mo-Au con diseminación de sulfuros rodeado de un amplio halo de alteración fílica-argílica. Vetas angostas, principalmente entorno de los cuerpos de skarn, tienen contenidos elevados de Au-Cu-Pb-Ag.

May 10, 2023

From time to time failures occur in structures made of lead, and the failure may be due to corrosion involving a definite thinning of the lead sheet, or it may be of such a nature that cracks develop and the lead appears to disintegrate. The idea of lead cracking will at once suggest something abnormal, for common experience shows that this metal is very ductile and will withstand considerable bending without showing any sign of fracture. Cracking, on the other hand, is usually associated with brittleness.Fig. 1 is a natural-size photograph of a cracked sheet of lead. Prior to photographing, the sheet was etched byimmersion in a solution of ammonium molybdate. Several characteristics of this crack will be evident. First of all it is distinctly a zigzag crack, and secondly it passes between, rather than through, certain well-defined areas which appear bright in the photograph. This is particularly noticeable at the lower end where the crack appears to terminate.

Jan 1, 1932

By K Watanabe

A relational database in which its complex contents can be navigated through a map interface (ie spatially enabling) is relatively a new concept yet attractive for geoscience fields. This concept is made possible using the new breed of geographic information system (GIS) that utilises component object model and relational database management system. Such sophisticated yet open and highly interoperable platform makes possible the integration of data management, analysis, and modeling processes into single workflow. Taking benefit of this technology trend, several initiatives emerge in geoscience to establish digital data models, such as the petroleum industry, the North America digital geologic map data model, and the ESRI geology data model. The mining industry unfortunately has not followed same paths due to the lack of data model and standards in its history. This paper presents an effort on establishing a digital data model for mining-related geoscience databases. The aim is to promote several standards by proposing a preliminary data model and demonstrating that the model is working for the mining business datasets. The case study is the island of Java, the western part of the Sunda island arc of Indonesia. Many types of datasets, such as geologic maps, topography, mineral deposits, structures, geochemical and geophysical data were dealt with and were transformed relational geologic databases of Java using the new Geodatabase geographic data model. Intelligent GIS tools were investigated for geologic applications, ranging from generic to specific purposes. Subtypes and domain were used to set up constraints, while topology rules and relationship classes were used to create links among data layers. The linear referencing system was used to model drillhole data. The current results show that the generic GIS and relational database can handle typical tasks related with mining business datasets. A preliminary data model is finally suggested.

Jan 1, 2004

By Chas. F. Jackson

The work of the mining division is divided between seven sections, each in charge of a supervising engineer, as follows: 1. Metal-mining methods section, the supervising engineer of which is also supervising engineer of the Southwest Experiment Station at Tucson, Ariz. 2. Metal-mining research section. 3. Nonmetal minim section. 4. Coal-mining section. 5. Mine-ventilation section. 6. Mineral-industries survey section. 7. Electrical section. The names of the sections indicate broadly the fields covered by each, and in the following pages the objectives and type of work of each section will be summarized briefly and the active problems listed. The work done during the calendar year 1936 will also be summarized.

Jan 1, 1937

By Ali Behrad Vakylabad, Esmaeel Darezereshki, Babak Koohestani

As a by-product of the steelmaking industry rich in iron and zinc, electric arc furnace dust (EAFD) landfill disposal is restricted in many countries due to the metal lixiviation risks. Several approaches have been examined to recycle or reuse EAFD. Hydrometallurgical methods mainly include the preparation of pregnant acid leached solution (PLS) using inorganic acids followed by selective metal recovery using different methods. We herein proposed a hydrometallurgical process initiated by acid leaching and finalized by thermal treatment to produce nano-ZnO from EAFD. At the condition of this study, only 67% of zinc was leached by sulfuric acid from EAFD into PLS while 98% of surplus leached iron was removed through precipitation by sodium hydroxide. Additional purification of iron removed PLS was accomplished using di-2 ethylhexyl phosphoric acid to extract Zn+2. The addition of ammonium hydroxide to purified PLS provided (Zn(OH)2)3(ZnSO4)(H2O)5 as the final precursor for nano-ZnO that ultimately transformed to nano-ZnO (60 ± 6 nm particle size) at 850 °C. The achieved results were scrutinized through various tests and analyses including TEM, XRD, SEM, EDS, FTIR, and TGA.

Mar 10, 2021

By Sirish L. Shah

It is now common to have archival history of thousands of sensors sampled every second over long time. Yet we frequently have process engineers complain:??.We are drowning in data but starving for information??. How can these rich data sets be put to use? This paper addresses the issue of information and knowledge extraction from data with emphasis on process and performance monitoring including fault detection and isolation. Most of the major plant, factory, process, equipment and tool disruptions are avoidable, and yet preventable fault detection and diagnosis strategies are not the norm in most industries. It is not uncommon to see simple and preventable faults disrupt the operation of an entire integrated manufacturing facility. For example, faults such as malfunctioning sensors or actuators, inoperative alarm systems, poor controller tuning or configuration can render the most sophisticated control systems useless. Such disruptions can cost in the excess of $1 million per day and on the average they rob the plant of 7% of its annual capacity. Over the last decade the fields of multivariate statistics and data visualization and analysis methods have merged to develop powerful sensing and condition-based monitoring systems for predictive fault detection and diagnosis.These methods rely on the notion of sensor fusion whereby data from many sensors or units are combined with process information, such as physical connectivity of process units, to give a holistic picture of health of an integrated plant. Such methods are at a stage where these strategies are being implemented for off-line and on-line deployment. This article attempts to outline the field of sensor fusion - the application of signal processing methods, in the temporal as well as spectral domains, on a multitude and NOT singular sensor signals to detect incipient process abnormality before a catastrophic breakdown is likely to occur Keywords: Process analytics, process and performance monitoring, multivariate statistical analysis, sensor-fusion

Sep 1, 2012

By Arthur Notman

TO present some idea of the magnitude of the gold-mining industry of Canada and the world, the records of 106 gold-mining companies currently paying dividends have been studied. Forty of these are in Canada, and 37 on the Rand in South Africa, these being all the straight gold-mining companies that paid dividends in the two areas in 1938. None of the base-metal companies that produce gold as a by- product, or even as a major fraction of the value of their total product, have beezl included. In addition, a group of 29 similar companies from Southern Rhodesia and the Gold Coast in Africa, India, Australia, Manchuria, Philippine Islands, the

Jan 1, 1939

By C. Rodriguez, T. BoBo

Comminution, being the energy intensive part of a mining operation receives much scrutiny by cost controllers, CEO’s, investors and others as the mining industry goes “back to basics” to reverse the decline in productivity which occurred during the mining super cycle. Blasting is the first and lowest cost per ton stage in the comminution value chain. The basic principle that effective blast design can optimize fragmentation from the Run of Mine (ROM) ore muck pile to improve productivity through digging, loading and crushing to grinding and increase mine site profits has been well documented. Benefits of controlling fragmentation in the blast include reduced wear on equipment, faster loading, increased truck loads while detecting oversize rocks at the muck pile can reduce the frequency of a blocked primary crusher. A second basic principle is a measure of particle size distribution (PSD) at each unit operation in the comminution cycle allows engineers to manage blast design to produce fragmentation in the ROM ore most suitable to optimize downstream unit processes to improve mine site productivity and profits. Split-Online® systems have measured PSD of rocks on conveyors from the primary crusher to the SAG mill for over 20 years. Split-Engineering partnered with various mining companies to develop Split-ShovelCam® to automatically measure fragmentation from shovels and excavators working the ROM muck pile. This paper takes the reader “Back to Basics” by discussing the use of real time fragmentation analysis at the muck pile as an important parameter to optimize energy factors required for each blast. Case studies are given. INTRODUCTION The basics of mining are: • Explore for and find economic resources of valuable minerals • Mine rocks containing valuable minerals using blasting • Crush and grind rocks to liberate valuable minerals (comminution) • Recover valuable minerals for sale Comminution is an energy intensive process which accounts for a major proportion of mine site costs. Effective blasting can improve comminution and deliver significant reductions to mine site unit costs, (CEEC, 2016). Engineers, scientists, builders and even philosophers have long promoted the phrase “measure to manage”; the premise being “you can’t improve what you don’t measure”. Blast Engineers measure fragmentation in ROM ore for feedback to manage energy input in the design of blast patterns to optimize the ROM product size for downstream operations, whether they be for ROM Leach or feed into the primary crusher.

Jan 1, 2019

By George Watkin Evans

The United States Geological Survey has estimated 1 that the State of Washington contains 11,412,000,000 tons of bituminous coal and 52,442,000,000 tons of subbituminous coal, in beds more than 14 inches thick. As the present rate of production is about 4,000,000 tons a year, Washington apparently contains coal enough to supply Pacific coast markets for many years. The character of the coal beds of Washington renders the production of clean coal very difficult, and a considerable proportion of the output is washed before it is marketed. In 1915 Washington ranked fifth among the States in the amount of coal washed, though only twentieth in total output. In that year 37.9 per cent of the coal produced in the State was treated in surface cleaning plants.

Jan 1, 1924

By K. V. Raj, VASU GANGRADE

Airflow in large-opening stone mines is largely dependent on the natural ventilation due to the large cross- section area of the opening. The openings of such stone mines are typically twice or thrice the size of typical underground coal or metal/nonmetal mines. Due to the influence of natural ventilation, air velocities as well as the static pressure drop in the mines are low. Mines rely on auxiliary fans to ventilate active faces to reduce contaminant exposure to mine workers. The National Institute for Occupational Safety and Health (NIOSH) is conducting research on ventilation of large-opening stone mines to reduce worker exposure to dust and other contaminants such as diesel particulate matter (DPM). In order to reduce worker exposure to dust and DPM, an understanding of the airflow pattern due to auxiliary fans in the mine is needed. Under this research, NIOSH researchers are exploring the computational fluid dynamics (CFD) modeling to understand the airflow behavior in large-opening mines. In this paper, the team is presenting the results from three-dimensional CFD modeling of airflow in a large-opening stone mine and investigating the effect of a fan placement with the movement of trucks.

Feb 1, 2025

By B. M. Monaghan

"The developments of the 1950s and 1960s have seen Canada become an international source of iron ore, trading in all geographical areas and hemispheres. Canada's production will significantly increase in the next decade. However, although the outlook is bright, iron ore producers cannot be complacent. Instead, we must weigh the factors that have brought about the development of the Canadian iron ore industry and examine the probable changes for the next decade that will affect its growth.Looking ahead in the 1970s, competition will be severe. Pressure on prices will continue as new sources of supply bid for long-term contracts and as steel producers continue to develop mines around the world. Rising costs will make these pressures more severe. We must balance the growth of the world's steel makers with the emergence of new supplies of iron ore. The iron ore industry is now part of a new era in which demand and supply are intermeshed, and the developments around the world are acting on the Canadian iron ore industry's future."

Jan 1, 1971

By Charles J. Zablocki, Robert J. Kamilli

"Abstract - Buried, possibly mineralized granite cupolas at the Silsilah tin deposit in Saudi Arabia (lat. 26°06' N, long. 42°40' E) have been successfully located using a closely spaced electric-field-ratio profiling technique. In this study, electrical fields at 27 and 270 Hz across grounded electrodes spaced 50 m apart were measured along six traverses. This method is interpretable by inspection, unlike the dipole-dipole technique, which requires mathematical modeling for interpretation.In the study area, the technique allowed the authors to identify and distinguish among unroofed granite cupolas, cupolas with their aplite-pegmatite apical contact zones intact, strong (quartz-rich) and weak (relatively quartz-poor) greisens, dikes, faults, and pervasively argillized rocks.This method should be useful in the valuation of other shallow mineral prospects in similar settings in other parts of the world, especially deposits for which the location of vertical contrasts is important, such as veins or mineralized zones associated with the apexes of small igneous cupolas."

Jan 1, 1993

By Karl-H. Daum

Over many decades, numerous feasibility studies have demonstrated, that the production of sulphuric acid remains the most viable option of sulphur recovery from smelter off gas and abatement of SO2 emissions to the atmosphere. This is particularly more pronounced as smaller but more concentrated off-gas flows are to be treated from smelters, and enhanced sulphuric acid processes be-come available. Off-gas handling systems represent a significant capital and operating cost burden to the metallurgical operation. Modern pyrometallurgical smelter processes for sulphide ores based on the use of oxygen-enriched air, produce relatively small off-gas flows with high SO2 concentrations in the smelter gas of 30?60 %-vol. of SO2. This is a prerequisite for substantial cost reductions in the smelter off-gas handling and treatment system. As an alternative to sulphuric acid production, numerous scrubbing concepts with alkali or dual-alkali combinations as well as organic absorbents have been proposed. Also the reduction of the SO2 to elemental sulphur has frequently been studied. Very few of those alternative processes have been built in industrial scale, but all were generally characterized by none sustainable operation due to cost reasons, problems with issues related to chemicals used and by-products or poor availability. Thus the traditional concept of converting the SO2 to sulphuric acid is most common, although regarded as un-economic, but is at least a proven, environmentally sustainable and reliable way of sulphur gas processing. With the high acid price levels these days, operating companies are even able to generate significant revenue with their otherwise ?fatal? acid. Even though smelter gas is available at high SO2 concentrations, in a conventional acid plant one would add large amounts of air to dilute the gas down to a suitable concentration of 12?13 (14) %-vol. SO2. Dealing with higher SO2 concentrations in smelter acid plants is not feasible, as the gas exit temperature of the catalytic oxidation step would exceed the allowable limit for the catalyst. Hence those conventional acid plants are characterised by the use of large equipment, i.e. high capital cost, high energy consumption and limited flexibility. The newly developed LUREC® process can handle off-gas with significantly higher gas concentrations, even in excess of 25 %-vol. SO2. It is entirely based on well-proven equipment and unit operations. The first industrial application, operating with 16?18 %-vol. SO2 will be presented in this paper, along with the fundamentals of the process. It will be demonstrated that the process requires inherently lower capital cost, fewer operating cost, offers better energy recovery and lower emissions as compared to conventional design. While most existing smelter acid plants would have some built-in spare capacity, any significant increase of smelter capacity, say of 30%, can basically not be accommodated without installing an additional parallel new acid plant unit. An add-on LUREC® module can remove any such restriction, while simultaneously de-bottlenecking the existing acid plant. The paper also discusses the present status of the add-on technology for smelter acid plant expansions with respect to technical boundary conditions of different process alternatives as well as economic and environmental aspects. Application of the LUREC® process to modern smelter acid plants operating with high SO2 gas concentration, will lead to a substantial reduction of the specific size of the gas processing equipment and equivalent savings in capital and operating cost. The LUREC® process is patented worldwide by OUTOTEC.

Jan 1, 2009

By Justin R. Patts, Andrew B. Cecala, A. KYLE LOUK, Emily J. Haas

The U.S. National Institute for Occupational Safety and Health (NIOSH) and the former U.S. Bureau of Mines (USBM) have put significant effort over the past four decades into researching and developing engineering controls and interventions to reduce mine workers’ dust exposures during the bagging and palletizing of industrial minerals. Workers who perform the manual bagging and palletizing of 50- to 100-lb bags typically have some of the highest dust exposures of all workers at mining and mineral processing operations. This paper provides an overview of available dust control technologies for bagging operations and presents the findings of a recent case study conducted at four industrial sand operations to identify the current types of bagging and palletizing technologies being used and to evaluate their effectiveness in reducing workers’ exposures to respirable crystalline silica dust. An evaluation is also performed to determine if further reductions in respirable dust levels can be achieved by incorporating additional modifications or improvements into the existing technology.