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By AIME AIME

AT the Morenci branch of the Phelps Dodge Corporation, of which Frank Ayer is manager, several new types of machines that have been developed by Charles Mitchell, shop foreman in the drill steel shop, invite comment for their time and labor-saving qualities. Foremost of these is an adjustable gage-block and gaging device for attachment to drill-sharpening machines, developed and patent applied for by Mr. Mitchell. It replaces the blocks on the standard Ingersoll-Leyner drill steel sharpener No. 5. Features of the device are gage blocks with a flat surface which can readily be removed when worn and planed in any flat planer; blocks that can be adjusted with a templet to give a far more accurate gage than was formerly possible; and a center stop that is adjustable and can be accurately set to center any standard size drill steel.

Jan 1, 1930

By T. S. Reddy

Research and Development Centre for Iron and Steel (RDCIS) a unit of Steel Authority of India Limited (SAIL) is continuously engaged in reduction of energy consumption at SAIL plants by implementing innovative and new concepts. In this regard, continuous efforts are being made to recover waste heat in Sinter Plants. This paper discusses existing waste heat recovery measures taken and proposed measures planned in Sinter Plants. One such effort is on waste heat recovery from sinter coolers. Hot sinter is discharged to the crusher at the end of the sinter machine at a temperature of 500 to 800°C. Temperature of hot sinter is brought down to nearly 100°C in the sinter cooler with air-cooling. The air after cooling the sinter is generally discharged to the atmosphere at about 225 to 300°C. It is planned to recover heat from the hot air that is being released to atmosphere and heat the process water, which is being added at ambient temperature in mixing drum at Bhilai Steel Plant. The temperature of raw sinter mix will be raised by addition of this hot water, which will help in improving the productivity of sinter machine. It is estimated that Waste heat recovery to the tune of 1.5 to 2.0 Gcal/h is possible with reduction in CO2 emissions in the range of 4000 to 5000 ton/year. The novel approach that is being adopted is addition of hot water in mixing drum for higher sinter productivity for the first time in India. Keywords: waste heat recovery, sinter plant, hot water generation, emission reduction, CDM

Sep 1, 2012

By V Dolmage

Copper Mountain is the third largest copper mine in British Columbia, and is now producing close to 20 million pounds of copper per year, with which is recovered also 4,000 ounces of gold and. 13,800 ounces of silver. After a long and checkered career, during which the ownership and management changed several times, this deposit finally came into the possession of the Granby Consolidated Mining, Smelting and Power Company in 1923. It was not, however, until the end of 1925 that the mine, under the management of Charles Bocking and C. H. Smith, was successfully placed on a basis of profitable production. It is a low-grade deposit of the contact-metamorphic type, with refractory ores consisting of chalcopyrite and bornite in a gangue of altered andesitic and basaltic breccia. The ore is concentrated to a product carrying over 30 percent copper, which is smelted in Tacoma. The deposit is 12 miles south of the town of Princeton, which is on the Kettle Valley railway, 150 miles east of Vancouver and 40 miles north of the International Boundary line. Princeton is served also by a branch of the Great Northern railway, which leads clown the Similkameen, Okanagan, and Columbia valleys. Copper Mountain mine and camp are connected to Princeton by a good mo tor road extending up Wolf Creek valley, while the haulage level of the mine, which emerges on the steep side of the Similkameen valley 1,000 feet below the camp, is connected with Princeton by a spur of the Kettle Valley railway leading up the Similkameen canyon and passing en route through Allenby, where the concentrator is situated.

Jan 1, 1929

By Varadarajan Seshadri

The performance of mould fluxes in satisfying its quality requirements can have a significant effect on the efficiency of the continuous casting process and on the surface quality of the products. This performance is affected by various parameters including the characteristics of the mould fluxes, the quality of the steel being cast and the operational conditions of the caster. The extremely complex relationships involving the parameters mentioned above make it very difficult to have simple criteria for selecting mould fluxes for casting a certain grade of steel in a continuous casting machine. These difficulties led steelmakers and mould flux suppliers to select mould fluxes based mainly on plant trials. In the present work, a software to help in the analysis and development of mould fluxes for continuous casting was developed_ This software includes several models for prediction of mould flux viscosity and consumption. A mathematical model was also used to predict the heat flux through the mould flux. The proposed methodology was applied to continuous casting of crack sensitive steels_ Some of the results given by this software are presented, discussed and compared to plant data.

Jan 1, 2003

By W. J. Fene

Ventilation is undoubtedly the greatest single safety factor in the operation of a coal mine. Any condition or occurrence that interrupts the ventilating current or changes its normal course through the mine workings is a distinct hazard and should be considered as such by every coal-mine owner, operator, and worker. The hazard, of course, is much greater in a mine that is emitting gas, as an explosive mixture can accumulate in a very short period if the ventilating current is interrupted. It is common to find one or more entries producing 600 cubic feet or more of methane per hour. If the ventilating current were short-circuited from these entries for 15 minutes, there would be an accumulation of 150 cubic feet of methane, which, when mixed with enough air to dilute it to the lowest explosive point, would make about 3,000 cubic feet of explosive mixture; this gas could be ignited in almost any normally operated mine by a cutting machine or other electrical equipment. The ignition of this quantity of an explosive gas-air mixture can readily cause an explosion of coal dust that would completely wreck the underground workings and possibly some of the surface structures. In fact, the ignition of one-tenth of the above quantity of an explosive mixture of gas and air might readily start an explosion that would, extend through every part of a large mine. The possibility of occurrence of interruptions to the ventilating current has received comparatively little consideration from mine owners, operators, and workers in many parts of the United States. Such a possibility should be considered in connection with every mine that gives off explosive gas, and steps should be taken to prevent it.

Jan 1, 1943

There are several simulators available and are being used for analysis, improvement and optimal control of the grinding process. However, these tend to be developed on informal software engineering methodologies. The informal approach is not suitable for long term development and a formal design methodology is necessary to develop efficient, error-free, and easy-to-use and to maintain software. In meeting this goal, basic concepts of a software model for describing the mineral process objects has been proposed. The software model forms the basis for software design and efficient implementation of the simulation. This paper describes the development of software models for grinding circuits. The work constitutes the theoretical foundation for the development of an advanced simulator for comminution.

Jan 1, 1995

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Guatemala has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State.

Oct 1, 1929

By J E. Everett, K Jupp, T J. Howard

Simulation modelling is a practice commonly used in the mining industry to evaluate alternative process designs. Such modelling is typically undertaken as an optimisation study to increase the efficiencies, productivity and product quality of operating mines. In this situation, real short-term grade variability data of extracted ore are available from production records as input data into the simulation.There is also a need for simulation modelling to be performed before mines are approved for construction to clarify the grade variability characteristics that can be expected from the operating mine and assist in the optimisation of the process design. In this situation no historical short-term grade variability data are available. To achieve meaningful and reliable results from a simulation it is necessary to have input data for the ore to be extracted from the pits, representative of the short-term grade variability that would be expected for the operating mine.This paper describes an example of a path taken to generate realistic input data.A method described as composite cut-off criterion was used to distinguish ore from waste, which gave substantially greater recovered tonnage at target grade compared to the conventional quadrant cut-off grade criteria.The only data available for the project was resource model data in the form of kriged block models, which are known to underestimate true ore grade variability. To achieve realistic results from the simulation it was essential to increase this variability while maintaining the accurate average grades. Areas of certain deposits that were modelled using both kriging and conditional simulation estimation techniques were quantitatively compared to establish the comparative variance and the kriged data was modified to match the conditionally simulated variance.A realistic mining model was generated via a process of discretisation and regularisation of the resource blocks. Quantitative assessment demonstrated that this method adequately compensated for ore dilution and that adjustment for ore loss was not required due to an ore skin surrounding the edge blocks.The conditioned data was then used to generate a schedule of daily mine extraction, considering grade variability, tonnage, equipment constraints and extensive blended-in-blended-out precrusher stockpiles to feed into the process design simulations.For the precrusher stockpiles a number of alternative allocation criteria were examined for ore being extracted from the pits to identify the best method in achieving reduced variability through the daily scheduling system. The study concluded that a single analyte separation criterion produced acceptable variability with minimal complexity.The blending efficiency of manually stacked and reclaimed precrusher stockpiles was studied to determine a realistic blending efficiency within the pile. A recommended method of building and reclaiming was determined to give maximum blending efficiency.Finally, the data was used as input into process design simulation models; simulation from crusher feed to shiploading demonstrating that control of shipment grade variability was achievable and that the conditioning of the data delivered realistic results.CITATION:Jupp, K, Howard, T J and Everett, J E, 2013. Generating synthetic data for simulation modelling in iron ore, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 231-238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Reinhard Gertl, Maximilian Weithaler, Harald Kammerer, Juan Pablo Muñoz, Juan-Carlos Rueda

The Guillermo Gaviria Echeverri tunnel and its access roads project in Antioquia, Colombia is a mega infrastructure project that includes a road network with the longest tunnel in Latin America and several short tunnels, the latter being the focus of this study. The design of the project required careful consideration of several special factors, such as the tunnels’ steep slopes of up to 5%, high fire load of 100 MW, bidirectional operation, and short lengths that make it difficult to place ventilation equipment. The combination of all these parameters cause a challenging design problem for the ventilation systems and smoke control of the short tunnels. To address this challenge, a risk assessment study was conducted to support the design of a new and innovative ventilation strategy that deviates from relevant guidelines and standards, like the Austrian RVS [1][5][6] or the German EABT [8] in order to provide a customized solution for this particular project. This strategy resulted a cost-effective solution, that allowed a reduction in the number of required jet fans and at the same time reaches or reduces the risk level compared to traditional ventilation strategies.

Jun 13, 2023

By I Gray

While in some cases it is vitally important to measure the virgin stress in rock prior to tunnelling there are a number of cases where such stress measurement is really not required. The concept of having to have a number to put in a numerical model representing a continuum is often quite inappropriate. This paper discusses the cases when virgin stress measurement is required and the most appropriate means to measure it. The techniques discussed cover all of the overcoring systems, hydrofracture and borehole breakout measurements. It also covers the use of rock surface stress measurement, which is easy to perform and should be used to check for changing stress conditions. Unfortunately this technique has been ignored in recent times because engineers are addicted to numerical models requiring far field stresses rather than measuring the real values that exist where they matter – at the tunnel wall. A case is presented in which the measurement of surface stress in a tunnel boring machine tunnel enabled the far field stress to be determined in what must be the world’s largest overcore.CITATION:Gray, I, 2014. The measurement of rock stress for tunnelling, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 153–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Verya Nasri

This paper will present the design and construction of a deep underground station of the Réseau Express Métropolitain (REM) project; the Édouard Montpetit station. The Édouard-Monpetit station is an interchange station that will connect the deeply sitting REM tracks to the existing metro station of the same name located closer to the surface. Édouard-Montpetit station is expected to be the deepest in North America, surpassing the famous Forest Glen Station. The various challenges and solutions put forth for the successful completion of this underground work are presented to serve as a valuable example for future deep excavation performed in urban area, in the close vicinity of highly sensitive structures.

Jun 13, 2021

By Walter E. Mingramm

THE construction of rescue-apparatus on the principle of furnishing the wearer with air from a tank containing it under high pressure was given up by inventors about 20 years ago. Such an apparatus must supply continuously, for not less than two hours, nearly 50 liters of pure air at atmospheric pressure per minute, or a total of 6,000 liters (210 cu. ft.); and a cylinder containing this amount of air, under 2,000 lb. pressure, would weigh 180 lb. or more. Although apparatus has been recently constructed utilizing liquified air, no experiments have been made to determine the regularity with which the air is generated, nor has its chemical composition been determined. Moreover, the chief objection to such an apparatus is the' difficulty and cost of keeping on hand a large quantity of liquified air. The system of furnishing the wearer of a breathing-apparatus with air which has given the best results, and has found employment in all the devices now in practical use, is that in which the air contained in the human lungs at the beginning of the work is regenerated by the apparatus. By means of chemicals, such as caustic potash and caustic soda, the carbonic acid gas, CO., exhaled is absorbed, and the oxygen that has been consumed is replaced from a tank containing this gas under high pressure. The pressure of the oxygen (which is 1,875 lb. in the two cylinders at the beginning of the work) is automatically reduced to 75 lb., and is sufficient to keep the air inside of the apparatus in constant circulation, and to force it to pass through the chemicals provided for the absorption of the CO, gas. In the attempt to construct an apparatus which would (1) furnish the wearer with a sufficient supply of air; (2) replace the amount of oxygen used up by the lungs during the time of

Jan 7, 1908

By Y. Mudryk, D. Paudyal, K. A. Gschneidner, V. K. Pecharsky, M. Khan

"Rare earth intermetallic compounds are utilized commercially as magnetic and battery materials, electron gun electrodes, etc. Several of these intermetallics will be briefly discussed. There are many other rare earth intermetallic compounds which are not utilized industrially but have unusual properties which are of fundamental interest and may have future technological applications. Several of these materials are discussed as well.INTRODUCTIONTens of thousands of rare earth intermetallic compounds exist, but physical properties (primarily their magnetic behaviors), other than their crystal structures have been measured for only a small percentage of these materials. Among these are the commercially important compounds: Nd2Fe14B, and the SmCo5 – Sm2Co17 family – well known high strength permanent magnets; (Tb0.3Dy0.7)Fe2, Terfenol-D, a giant magnetostrictive material; LaNi5Hx a critical component of the rechargeable Ni metal hydride batteries; and LaB6 an electron emitter. There are, however, many other intermetallic compounds which are not utilized industrially, but none-the-less, exhibit interesting, and sometimes, exotic physical properties which are of fundamental interest and may have some future technological significance. These include: the giant magnetocaloric effect compounds Gd5Si2Ge2 and La(Fe13-xSix)Hy; the RCu and RAg families of ductile intermetallics; the mixed intra-lanthanide (R,R')Al2 compounds in which magnetic transitions disappear and reappear as one R is substituted for by R'; and GdNi which exhibits large dilations along two crystallographic directions and a larger contraction in the third direction at the Curie temperature resulting in zero volume change as GdNi orders magnetically via a second order phase transition.COMMERCIALLY IMPORTANT INTERMETALLICSNdFeB Permanent MagnetsThe Nd2Fe14B permanent magnets were discovered in 1984 independently in the USA and Japan. It is a ferromagnet and with proper heat treatment and processing Nd2Fe14B is the strongest near room temperature permanent magnetic material known today. This intermetallic compound is utilized as a permanent magnet in many applications, such as electric motors (e.g. the modern automobile contains up to 35 electric motors), spindles for computer hard disc drives, microphones and speaker magnets for cell phones and other audio equipment, direct drive wind turbines, actuators, and Magnetic Resonance Imaging (MRI) units. There are two kinds of NdFeB permanent magnets – bonded and sintered. The bonded magnets have a lower magnetic strength than the sintered magnet. The highest strength magnets are obtained by small substitutions of Dy (up to a maximum of 10%) for Nd, because Dy can significantly increase the coercivity and thus the energy product (a measure of the magnetic strength or hardness). The bonded magnets account for about 12% of the NdFeB market (~82 metric kt per year, containing ~20 kt/a of Nd). The NdFeB permanent magnet market is growing at a rate of about 15% per year. (Burzo & Kirchmayr, 1989; Kobayashi & Hirosawa, 2001; Coey, 2011)."

Jan 1, 2012

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

It is no longer adequate when starting a new mine to simply select the best equipment. Today's competitive international commodity markets demand superior efficiency which requires systematic involvement of people in continual improvement of production and commercial processes. True Total Quality of Management (True TQM) principles provide an operating philosophy for maximising productivity and minimising unit costs of output. The presentation will show the practical and successful use of these principles. This paper will introduce the case study and provide background material on True TQM.

Jan 1, 1995

By X Ling, M Barati, E Moosavi-Khoonsari

In the pyrometallurgical process of secondary lead recycling, a desulfurising agent, such as Na2CO3 is added to minimise the emissions of sulfur into the atmosphere, while silica is introduced into the smelter as a fluxing material. Subsequently, a significant amount of Na2O and SiO2 remains in the downstream reverberatory furnace and blast furnace slags. However, there is limited understanding of the thermodynamic behaviour of silicate-based lead slags rich in Na2O, posing challenges in accurately determining the optimal condition for targeted metal recovery and final slag composition. In this work, the equilibrium phase relations of the PbO-Na2O-SiO2 system in the primary phase field of Na2SiO3 are studied from 800 to 1000°C via equilibration-quenching method. Samples with different compositions were prepared and held in platinum capsules in air at these temperatures to reach equilibrium. The equilibrated samples were subsequently quenched and the phase compositions were measured by electron probe microanalysis (EPMA). The results were then compared to those of previous studies and any discrepancies were resolved.

Jun 19, 2024

By C. Harry Benedict

This paper presents the details of milling practice and costs at the conglomerate mill of the Calumet & Hecla Consolidated Copper Co., Lake Linden, Mich., and is one of a series on milling methods being published by the Bureau of Mines. GENERAL DESCRIPTION The mines of the Calumet & Hecla. Consolidated Copper Co. are located in the Keweenaw Peninsula of northern Michigan. The mines of this district lie in a belt not over 4 miles wide and 100 miles long, which contains more or lees commercial ore. The Calumet & Hecla properties are the farthest north, except for the Seneca, of the operating mines. The district borders on Lake Superior, and by means of the Portage and Torch Lake waterways the largest lane vessels, can transport coal and other supplies from the lower Lakes directly to the company docks.

Jan 1, 1930

By B. Anamaeric

Economic, environmental and operational disadvantages of the traditional blast furnace process has led to the development of direct smelting reduction processes, including those that utilize self reducing/ fluxing dried greenballs as iron oxide feed materials. This is mainly due to improved carbothermic reduction, carburization and reaction kinetics. In this paper, the morphological changes of the greenballs as they transform to pig iron nuggets are examined over time at a constant temperature of 1,400° C. The products produced after each treatment were characterized using optical microscopy, scanning electron microscopy/energy dispersive spectroscopy and point counting/image analysis. The changes in the percent metallized area, wustite dendrite and slag matrix content of the structures were calculated. It was determined that the transformations were initially controlled by dissolving and containment of iron oxides in the molten slag and their consequent reduction to iron, followed by coalescence of the metallized areas. The final transformations were controlled by the carburization of the metallized areas.

By William J. Campbell

These investigations were undertaken as part of a program to determine the optimum X-ray spectral lines to use for analyzing the wide variety of samples received by the X-ray Laboratory. Theoretical calculations and experimental data derived from these investigations show that longer wavelength spectral lines, > 2A, are very useful for many analytical problems. Because of the low fluorescence yield of the elements of atomic numbers 13-22 and the small depth of penetration of their X-ray spectral lines, these elements were originally considered to be insensitive; however, these studies show that the wide dispersion of their spectral lines, coupled with their weak beta lines, permits the use of wide collimation, thus increasing the line intensity. More importantly, the background due to scattered primary radiation is very low in the long-wavelength region.

Jan 1, 1959

By T. C. Sun

Two wasted activated sludges (WAS), from an industrial wastewater treatment and a sewage treatment plant respectively, and 7 collectors are used to investigate the feasibility of air flotation thickening of WAS by adding the collectors used in mineral processing. The collectors experimented include straight chain fat acids with different chain length, sodium oleate, alkyl sodium sulphonate, sodium dedecylsulfonate, and dodecylamine. The results show that the thickening efficiency varied depending on different collectors. Of the collectors experimented, dodecanoic acid and dodecylamine are best collector for thickening both sludges.

Jan 1, 2014