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By Clyde E. Williams

MODERN steelmaking has gradually evolved from an inefficient small-scale operation, utilizing tiny units, to a highly efficient one utilizing large units almost completely mechanized. The leading position of the United States in the steel industry is due to the possession of easily assembled high-grade raw materials and large-scale highly developed plants. Modern integrated steel operation is largely one of material handling. Mining and transportation of iron ore, coal, and fluxes, coking the coal in by-product ovens, smelting the ore with coke and limestone in blast furnaces, converting the resulting pig iron into steel in the Bessemer, or in the open hearth when supplemented with scrap, and fabricating the resulting steel ingots in the shapes of commerce all are done on a huge scale, mostly by machinery, most of the labor being employed either in operating the machine or keeping it in repair. At the same time the quality and uniformity of the product have been greatly increased by the development of scientific knowledge and operating skills. Thus, the steel industry in this country is highly developed both mechanically and technically.

Jan 1, 1942

By E. Siami-Irdemoosa, S. R. Dindarloo

"Discrete event simulation is a stochastic mathematical modeling tool with applications in queuing systems. Many mining operations, both surface and underground, can be simulated in the context of queuing theory , for example open pit loading and haulage operation, underground level and vertical transportation, and mineral processing circuits. A computer simulation model of the operation is an invaluable tool to study both the system’s dynamics and conducting sensitivity analysis on different effective elements on system performance. In this paper, merits of discrete event simulation in decision making in mining engineering is discussed. Moreover, a stochastic simulation framework for selection and sizing of shovels and dump trucks in surface mining is presented to elaborate one example for applicability of the method in mining operations. INTRODUCTION Mathematical modeling is a valuable tool in design, optimization, and decision making in both surface and underground mining operations. Several researchers have tried to study different aspects of mining operations using a wide range of mathematical techniques such as linear programming[1], analytical hierarchy process [2], non-linear programming[3], genetic algorithms[4-5] ,mixed integer programming [6], machine repair model[7], queuing theory [8], and conventional spreadsheet calculations based on experience and engineering judgments. There are different uncertainties in typical mining operations (e.g. material loading and haulage, drilling, and blasting). For example, in a truck-shovel operation, different governing activities such as loading, haulage, and dumping cycles are stochastic variables. Moreover, analytical modeling of a large truck-shovel operation is very complicated. Thus, application of analytical and/or deterministic techniques cannot guarantee a solution for different problems that are encountered in daily mining operations. Discrete-event system simulation (DES) is a modeling method for such time discrete and probabilistic phenomena [9]. DES has been employed by different researchers in mining engineering through available software and languages such as GPSS, SIMAN- ARENA, and SLAM [10-14]. Most of the studies so far, tried to evaluate some “what-if” scenarios, to understand the possible effects of changing different input variables on overall mine economics. For instance, Baffi and Ataeepur (1996) used Arena to simulate a truck-shovel operation [10]. Also, Sturgul has conducted extensive studies in the application of DES in the mining engineering field [15- 17]. A very good background review of application of this technique in the industry can be found in [15-16]. Previous studies have shown that, different approaches including deterministic, stochastic, and experimental methodologies result in considerable differences in outputs [18]. These techniques lead to different solutions, regardless of the quality of technique/software itself or knowledge of the modeling team. Hence, the first step is to develop a comprehensive simulation framework to obtain nearly the same optimal results for the same input variables, regardless of the employed technique."

Jan 1, 2016

By L. B. Phelps

Current mining regulations require revegetation in reclaiming surface nines. Excessive soil compaction can be an impediment to successful revegetation in poor soil conditions common to Eastern coal nine sites. A field study was performed to determine the bulk densities of soils that had been spread by either bulldozers or scrapers at a strip nine site. Moisture-density relationships for the soils were determined from the field samples. These were compared with stockpile samples compacted by the Standard Proctor compaction test. The results of the study indicate that the degree of compaction could be lessened through proper soil handling procedures.

Jan 1, 1986

By Haofeng Xie, Lijun Peng, Xujun Mi, Xue Feng, Xiangqian Yin, Zhen Yang, Guojie Huang

The Cu/Al composite wires have been widely used in cable industry. Especially in the development of aerospace, the light weight character of wires is particularly important. The wires are fabricated by a drawing process and heat treatment. Mechanical and electrical properties are measured and analyzed. The bending behavior is studied by scanning electron microscope. INTRODUCTION Cu/Al composite is a typical bimetallic composite that has been used in plenty of fields such as automobile and aerospace. The composite has the advantages of excellent conductivity as well as low weight, which cannot be obtained from single copper or aluminum. Industrial products of Cu/Al composite include Cu/Al composite joints (Uscinowicz, R., 2013), Cu/Al bimetallic sheets (Li, X. et al., 2011), Cu/Al flat bar (Wu, Y. & Liu, X. & Xie, J., 2014) and CCA wires (Ahmed N., 1978). CCA wires refer to the composite wires that copper layer concentrically coated on the surface of aluminum core conductor, implementing solid combination of two metals on the interface and forming an integral. At present, the aircraft cable generally use copper or copper alloy conductor, which makes the wire in the aircraft occupy a considerable proportion due to the large density of copper. Therefore, the use of Cu/Al composite wires instead of copper wires for weight loss, is of great significance to the development of aerospace technology industry. Heat treatment is an indispensable procedure to improve plasticity during cold working process, which is of great importance to preparation of wires (Wang, Q. et al., 2008). During the heat treatment, the Intermetallic Compounds (IMCs) are inevitable formed at the contact area of Cu/Al due to the occurrence of diffusion (Lee, S. et al., 2012). According to the results of former researchers, kinds of IMCs were discovered. Antoine Gueydan (2014) identified the formation of three IMCs (Al2Cu, AlCu, and Al4Cu9) at the interface between copper and aluminum after thermal aging. IMCs have a significant effect to the properties of Cu/Al wires. Bending performance is a vital property for the actual application of wires. The brittle IMCs may create a stress concentration that can cause crack initiation during bending process. This work focus on the mechanical properties of Cu/Al composite wires after heat treatment. The effect of various annealing condition on mechanical and electrical properties are studied, in order to find the appropriate annealing conditions, which produce optimal combination properties of Cu/Al clad composite wires. Bending fracture of composite wires is discussed by morphology observation.

Jan 1, 2019

By Alexandre Bonan

This paper reports the results of a kinetic study on the oxidation of free cyanide and Cu-cyanide complex ions with HO,. The variables and respective ranges studied were the following: [CN] total =10 - 500 mg/l; pH=10-11; (H2O2/CN) mole ratio = 1- 3; (Cu/CN) mole ratio = 0.10 - 0.25. The results were interpreted by a semi-empirical model that incorporates the useful oxidation reactions and the parallel alkaline decomposition of H2O2

Jan 1, 1994

By P. J. Bartlett

Premier Diamond Mine exploits a kimberlite orebody using cave mining methods. A drilling level is established at the base of a block of ore to effect undercutting that leads to caving of the overlying ore. A second level is developed some 15 metres below the undercutting level to allow extraction of the ore once it has caved. As much as 45 per cent of the rock is removed on the extraction level creating a series of pillars. Undercutting creates abutment stresses, as high as 3 times the virgin stress, which affect the rock mass to a distance of 20 metres from the undercut face on the undercut level and on the extraction level 15 metres below. If the extraction level is completely developed prior to undercutting, where stress levels exceed 20 percent of the rock mass strength, extensive rock mass and support damage occurs as the undercut passes overhead. Rock mass damage takes the form of movement along existing joints and minor shear failure through intact rock. Support damage takes the form of cracking in rigid concrete linings. Where induced stresses exceed 50 per cent of the rock mass strength it is often impractical to keep excavations on the extraction level open. Rock mass damage takes the form of extensive failure of the rock in shear which evidences itself as propagation of the fracture zone around tunnels and footwall heave. Support damage results in destruction of shotcrete linings and concrete footwalls. As the interbolt support fails, badly fractured rock ravels around the steel tendons. Observation and monitoring at Premier Mine and on other cave mines has shown that induced stress levels and consequent damage are a function of :?the extraction ratio on the undercut and extraction level prior to undercutting ?the shape of the undercut face ?the rate of undercut advance ?the distance of leads and lags between adjacent tunnels on the undercut level. To ensure the stability of excavations, all of the above parameters must be carefully planned and the planned mining sequence rigidly enforced. The minimum of development is completed on the extraction level prior to the undercut passing overhead. Required development is then rapidly completed once the area has been de-stressed. Support is installed in three phases: ?Rockbolts are installed as soon as excavations are developed ?Wire mesh, steel tendon straps and a layer of shotcrete sufficient to protect the mesh and straps from damage by blasting and LHD loading is installed as soon as practical thereafter. Inevitably the shotcrete lining has to be replaced once the undercut has passed overhead.. ?Rigid shotcrete linings and concreted footwalls are completed only after the undercut has passed overhead and the area has been de-stressed.

Jan 1, 2000

By H. R. O'Brien

"During the past year, the Pittsburgh experiment station of the Bureau of Mines has been investigating methods for the quantitative estimation of carbon monoxide in blood. This work was necessary because reliable methods of analysis are of the greatest importance in the bureau's research work on prevention and treatment of carbon monoxide poisoning among workers in mines and metallurgical plants. Two of the methods considered involve color comparisons. In one of these methods, differences in tint can be noted fairly readily, while in the other, they are much more difficult to detect. The latter, however, is otherwise considerably simpler. It was decided, therefore, in studying the possibilities of this second method, to use the most sensitive eyes in the laboratory force.Preliminary trials.The method under investigation was the Haldane carmine determination of carbon monoxide in blood. The plain oxyhamoglobin of the blood in dilute solution is a pale straw color, when exposed to carbon monoxide it becomes a cherry pink. In the analysis dilute indigo carmine is added to oxyhsmoglobin until the solution matches in tint the carbon monoxide hemoglobin. The eye wanted, then, was the one most sensitive to faint pinks. But just how to select the analyst was not clear At first the Williams test scale, used in the Navy, was considered, but on con¬sultation with Dr. L. L. Thurston, bead of the Department of Psychology at Carnegie Institute of Technology, the following procedure was adopted.Instead of standard tests made up of all colors, only those occurring in the analysis were used. Solutions were prepared of the two hemoglobins, from which twenty-four different pairs were made up and placed in test tubes like those expected to be used in the analysis. One of each pair differed from the other in percentage of carbon monoxide hemoglobin by amounts varying from 2-1/2 per cent to 20 per cent. Each pair was compared in a box built in our own shop. This was 20 inches long and 5 inches square in cross section. One end was covered with ground glass. Just inside this glass cover were provided two slots, each the width of the test tubes used. The tubes to be compared were dropped into these slots through two holes in the top of the box. The device was placed before a window away from the sun, and so arranged that the light conditions were the same on each slit or opening. The person to be tested was seated before the box, and as the two tubes were placed before him side by side, he marked whether A (left) or B (right) contained the more cherry pink. This procedure was continued till he had compared all the pairs."

Jul 1, 1921

By Mahmut Yavuz

to in Old Uighur Turkish as Tolay kopugu, in Ottoman Turkish as Derya kopugu, and in modern Turkish as Luletasi. Scientifically known as sepiolite, it is represented by the formula Si12Mg8O30(OH)4(H2O)4(8H2O). Sepiolite is a natural clay mineral composed of hydrous magnesium silicate, characterized by a structure of alternating blocks and tunnels that develop in the direction of the fiber. Each structural block contains two silica tetrahedral sheets surrounding a central layer of magnesium oxide- hydroxide. Sepiolite exists in two distinct forms in nature: alpha-sepiolite and beta-sepiolite. Alpha- sepiolite is amorphous, compact, and resembles pellets that look like sea froth, hence its Turkish name Luletasi. In contrast, beta-sepiolite appears as amorphous aggregates or small, flat, round particles. These two forms exhibit different physical properties. Meerschaum was also studied by Brauner and Preisinger in 1958, who agreed that it primarily consists of sepiolite (2MgO·3SiO2·nH2O). According to these researchers, water is present in its mineral, zeolitic, crystal, and structural forms. Meerschaum is commonly used for adsorbing various liquids, as an ion exchanger, and for dispersing and insulating paraffin in the chemical industry (Gokdemir and Dogan, 2011). Sepiolite deposits of the meerschaum type are primarily found in Turkey, Somalia, Tanzania, Kenya, and Mexico. Alongside high-quality, low-density, and highly porous meerschaum, Somalia also has sedimentary sepiolite formations. The total reserves of these deposits are estimated at around 50–100 million tons (Sariiz and Isik, 1995). Meerschaum, also known as “white gold” or “sepiolite,” is a unique mineral highly prized for its lightness, heat- resistant properties, and ability to be carved into intricate designs. Found predominantly in Eskisehir, Turkiye, meerschaum mining and processing have become significant contributors to the local economy and cultural heritage. This paper explores the history, economic importance, mining practices, and environmental impacts of meerschaum mining in Eskisehir and discusses the challenges and opportunities faced by the industry.

Feb 1, 2025

By R. A. Masumura, C. S. Pande, D. Agassi

"Grain size has a different effects on the critical current density (Jc) of high and low transition temperature (Tc) superconductors. In high Tc superconductors, the critical current density Jc across grain boundaries depends sensitively on the misorientation 8. It was pointed out by Pande that this dependence is directly related to dislocation structure of the grain boundaries i.e., it is due to dislocation cores and stresses. These ideas are developed further in this paper leading to a relation between Jc and 8. The analytical result is compared with the experimental results on bicrystals and used to explain the difference in behavior between high and low Tc superconductors.IntroductionThe grain size distribution and its evolution with time and temperature is important in determining the properties of high and low transition temperature (T c) superconductors. The distribution is a convenient function to characterize the processing of a high Tc material during sintering. For example, it is known that the maximum density of ceramic materials is obtained when the grain growth is reduced but grain boundaries are still mobile. For practical superconductors, the processing parameters are selected to achieve optimum properties: highest possible T c and maximum critical current (Jc). In terms of an average grain size, the requirements for optimum T c and Jc are sometime in conflict. In A15 type superconductors and even in NbTi, larger Jc have been measured in smaller rather than larger grain sized material. Conversely, in a high Tc materials like YBa2Cu307, higher Jc have been found in larger grain sized or single crystal specimens.Extended defects such as grain boundaries in low T c superconductors can be effective pinning agents for magnetic flux lines, thereby increasing the transport critical current density of these materials [1]. On the other hand, the transport critical currents in polycrystals of high Tc superconductors such as YBa2Cu307 is found to be relatively small (much smaller than those in single crystals of the same material) [2]. It is now known that grain boundaries in high Tc polycrystals can in many cases form ""weak links"" reducing the critical current density across them. This phenomenon can be studied more precisely by experiments on bicrystals, where there is only one grain boundary. It is found that the critical current density is quite sensitive to the misorientation angle of the bicrystal [3,4]. Although the original experiments were conducted on YBa2Cu307, other Tc superconductors have been shown to give the same result [5]."

Jan 1, 1994

By William Laird

In the process of mining coal today, our greatest asset, the coal miner, is faced with the indirect and direct consequence of underground mining operations. The indirect considerations may be the rank of the coal seam, the amount of overburden, geological factors, seam permeability and cracks. The introduction of newer, bigger and faster coal-producing face equipment having the capability to cut or rip through the bedding planes, cleats and micropores of the coal seam brings about rapid liberation of gas accompanied by greater concentrations of coal dust, has exerted a direct consideration and greater demand upon mine ventilation systems and dust control. The purpose of mine ventilation is to provide sufficient pure air to the miners working underground and to dilute, render harmless, and carry away all the dangerous and noxious gases. The mining operations which create coal dust are cod cutting, drilling, blasting, loading, hauling, dumping and movement of face equipment. The created fine dust causes the propagation of explosions. When quantities of coal dust with no methane present are raked in a sufficiently dense cloud in the presence of a source of ignition, an explosion is possible.

Jan 1, 1980

By K. C. Mills, P. N. Quested, A. P. Day, R. F. Brooks

"Methods have been developed to measure the physical properties of molten materials relevant to the fluid flow in high temperature processes. Data for the densities, viscosities and surface tensions of Al-, Ni- and Fe-based alloys are compared with (i) values for the pure metals and (ii) estimated values obtained from models making use of chemical composition of the alloy. Experimental values for metallurgical slags are also given and compared with estimated values.1 IntroductionPhysical property data has proved very useful in improving process control and product quality. For instance, in the continuous casting of steel the viscosity (TJ) of the mould flux is important since it determines (i) the optimum casting conditions, nVc = 2.5±1 dPas (m min-1) where V c is the casting speed and (ii) the level of slag entrapment (which leads to inclusions) in the metal. Thus data for properties like viscosity are exceedingly useful in understanding the process and the problems encountered and the causes of defects and problems.Another interesting development which has helped to increase our knowledge of processes and improve process control and product quality is the development of mathematical models of the fluid and heat flow in the process. These models have been developed to the stage where one of the prime requirements is for good physical property data for the industrial materials involved. Recently, Oxley [1] has shown that the use of reliable, experimental, property values for the commercial alloy in a commercial software package produced a significant improvement in the prediction of casting defects. Thus reliable property data are required for liquid metals but also for (i) liquid slags since many processes involve the use of a slag to refine and protect the metal or to lubricate the mould and (ii) refractories, sand and investment moulds."

Jan 1, 1999

By C Itotoh, K O’Halloran, L Karlson

Global methods used to explore for minerals have progressed relatively slowly since the development of the first diamond core drill in 1863. Since then, key developments such as wireline geophysics (1920s), the tricone drill bit (1930s) and aeromagnetic surveys (1940s) all occurred in response to global events. In this project, BHP’s WAIO Geoscience operations team hypothesise that a global movement towards a greener future as well as an increasing intolerance for safety events will drive another step change in exploration methods. We have leveraged our relationships with exploration contractor partners and industry leaders to develop a realistic vision for 2033 and beyond, where drill rigs, earthworks and geophysical units are operated and maintained remotely; emissions of dust and waste are eliminated; hazardous energy sources are controlled; procurement is based on sustainability rather than cost and carbon emissions are tracked with the same rigour as production metrics. We have combined these visions into a series of graphical illustrations with the aim of inspiring ourselves, our vendors and our peers to collaborate further on producing a step change in our industry.

Sep 18, 2023

By M. J. Zdunczyk

Located approximately 50 miles northeast of Knoxville, Tennessee, Short Mountain Silica mines the Clinch Formation, an orthoquarzite, for silica sand. In 1980, a Knoxville resident and area contractor visualized mining Short Mountain for silica sand. Because APG Industries, the main market for the glass sand product, was only 48 kilometers from the site, many silica sand companies became interested in the property. In 1986, J.D. Nicewonder began to develop the site, and in May of 1988, APG Industries received the first sand shipment.

Jan 1, 1992

By Joshua Hoffman, Braden Lusk, Kyle Perry

Shock tubes are used to simulate large-scale arena explosions without the use of full-scale arena sites that utilize large quantities of explosives. Instead, small explosive charges can be used to drive shock tubes. When this is done, the geometries of the explosive charges can alter the resulting pressure time curve. A common geometry chosen for the explosive charge is a sphere in order to be congruent with the spherical shockwave that emanates symmetrically in three dimensions from the detonation point. This paper reports on the findings from experiments that study the effects of altering the charge geometries and explosive types while keeping the TNT equivalency constant. Peak pressures and durations were affected by these changes. Directional phenomena are exaggerated by the use of certain charge shapes and detonation points. The speed of the detonation front in the explosive being greater than the speed of the shockwave in air played a critical role in the resulting pressure time waveforms. Waveform manipulation can be used to generate job specific waveforms that ultimately benefit the shock tube operators and their clients.

Jan 1, 2010

By J. A. Kost

The objectives of this contract were to determine the amount, size, and deposition of float coal dust (74 x 10 microns) generated during the mining and transporting of coal in underground U.S. mining operations. Rock dust distributed by trickle dusters was also sampled. In addition to four belt-transfer points, two continuous and two conventional mining sections were sampled at five mines located in Pennsylvania, West Virginia, Kentucky, and Illinois. Float-dust samples were collected on deposition pans; total airborne dust was collected with MSA Model C personal samplers equipped with Unico filter casettes; Andersen cascade impactors provided relative size distributions of the samples. Production, airflow, and water flow were monitored to examine their effect on dust levels.

Jan 1, 1981

By Auã Kiahla, Tomi Kouvonen, Vinicius Miranda

Through numerical mathematical processing (Taylor’s approach and numerical derivation) the original data supplied by the accelerometer’s sensors was transformed into velocity and, after the data mining, a statistics residue analysis was applied in order to evaluate if the data from the prototype and from the traditional seismographs were similar. The data from each system was used to estimate the attenuation law and the results are shown in this paper

Feb 1, 2020

By George S. Rice

"The author was a member of a Commission sent by the Secretary of the Interior to France to investigate developments in mining and metallurgy under stress of war conditions, and also to observe the extent and character of the destruction of the collieries and the steel and iron plants, and methods which were being taken to reestablish them. This commission consisted of F. G. Cottrell, Chief Metallurgist of the Bureau of Mines, Frank H. Probert, Dean of the University of California Mining School, and George S. Rice, Chief Mining Engineer of the Bureau. While conducting this investigation a trip was made to the Saar Basin to observe the conditions there. Following this Mr. Rice acted as advisor on mining matters to the Representative of the Economic Council in an Interallied conference held at Cologne in April 1919, and subsequently visited the mining districts in central and southern France, Belgium, and Great Britain.The Germans, in planning a campaign for world supremacy, had as one of their first objectives the seizing of the important Briey iron ore deposits of France and the coal fields of Belgium and northern France.Large resources of coal and iron have led to the commercial greatness of the countries possessing them, as exemplified by the great development first in England then in the United States, and in Germany when the minette high phosphorus iron ores became useful through the invention of the Thomas and Gilchrist dephosphorizing process in 1878. However, this development was anticipated by the German scientific advisors in 1871, and led to the then known deposit of minette ore in Lorraine being taken from France by Germany.When these ores became available, Germany made such tremendous strides that its minette ore developments were not sufficient and importation of ore was necessary. Meantime France, by drilling, had established the extension of the minette ore field into French Lorraine. Then it was discovered that France had greater resources, while the German resources were being rapidly depleted.Although Germany, in its Westphalian basin, possessed the most important coal field on the Continent, containing the largest resources in coking coal outside of Great Britain, its coal was distant from the sea coast, so it could not be an important factor in the export business. No doubt this fact caused the German Imperialists to look forward: to securing the coal basin of Belgium and northern France for future ocean trade.It was a striking feature in the German conduct of the war that, although the steel and iron plants of Belgium and France and other industrial establishments in the invaded regions of Belgium and France were utterly destroyed, the iron mines in French Lorraine were not destroyed nor materially damaged by the Germans in their retreat, while the destruction in France continued until the day of the Armistice. The other striking fact is that the coal mines Of Belgium were not destroyed. It can only be conjectured whether this was due to President Wilson's threat of retribution, which did not stay their hand in France, or was due to the fact that they did not consider Belgium as a real competitor. It was evident they wished to cripple France industrially when they could not hold these northern provinces."

Dec 1, 1919

By A. von Röpenack

A forecast of the consequences of our techniques and goods produced, at least a technical assessment will be demanded from us as an industry. The hydrometallurgical winning of zinc is therefore at a crossroads. New processes promise not only better economics, better maintenance of resources and simpler operation, but also more harmony with nature. Pressure leaching promises to eliminate roasting and thus one complete process step. The hematite process solves a difficult and always costly iron problem. HOA opens a possible road to a totally new ,generation of electrolysis. Zinc has a long tradition behind it. Its? importance is as great as ever-. There is still room for new production developments. In my estimation there are good chances for successful new techniques? which will benefit our whole industry. Zinc is a modern and forward-looking metal.

Jan 1, 1990

By L., Ormsby

DRILLING and blasting practices in the Morenci open pit have undergone considerable modification in recent years. Changes in the character of the ground being mined, modifications of working conditions, and continuous experimentation have been the contributing factors.

Jan 1, 1950

By T. Tomioka

1. An Overall View of the Japanese Ferroalloys Industry 1) Depressed Demand for Ferroalloys: In Japan consumption of ferroalloys in the last ten years has decreased, although there has been some fluctuation from year to year. During this term production figures of the steel industry, which are closely related to consumption of ferroalloys, are as follows: Shipment of steel products for the domestic market has declined gradually from 69 million tons in 1979, which was the peak year for steel production, to 60.3 million tons in 1982 and 60.4 million tons in 1983, the level of 1978. In addition, exports also have been a downward trend since 1976, which was the peak year with tonnage of 34 million tons, to 28 million tons in 1982 and 31 million tons in 1983.

Jan 1, 1984