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By H. Colin

The basic industry, such as mining, ferrous and non-ferrous, cement and aggregates, stores and handles millions of tons of raw materials, re- quiring often different types of storage, blending and reclaiming systems.

Jan 1, 1980

By Wolfgang Pietsch

DR iron') is a generic term for metallized product that results from the direct or solid state reduction of iron ore. In direct reduction, iron oxides are reduced to metallic iron in the solid state without an intermediate melting step. MIDREX ® Iron is the DR iron material produced in the MIDREX ® Direct Reduction Process. Except for some thermal and mechanical degradation, the external physical form of as-reduced DR iron is the same as the feed material. Chemically, oxygen associated with iron is removed leaving a very porous structure. Figure 1 is the scanning electron micrograph (SEM) of the internal surface of a MIDREX Iron pellet obtained from a Swedish oxide pellet during reduction at 760 °C. Figure 2 is the SEM of a polished and etched cross-section through the same pellet showing the amount of intraparticle porosity. As a result of this high porosity, apparent density of DR iron is relatively low, typically a¬round 2 g/cm3, and specific surface is extremely high, typically around 1.0 m2/g or more. Both density and specific surface depend on the raw materi¬al and the operating conditions of the direct reduction plant. Normally, more than 97% of the available iron is reduced into metallic iron with the rest mainly in the form of wustite (FeO). During direct reduction, the gangue in the iron remains essentially unchanged. Removal of oxygen and the corre¬sponding reduction in weight result in a slightly higher percentage gangue in the product than in the raw material.

Jan 1, 1976

By Wolfgang Pietsch

Direct Reduced Iron is a product obtained during solid state reduction of iron oxides into metallic iron. General chemical and physical characteristics of all direct reduced iron materials result in a noticeable reoxidation tendency and a relatively low ignition temperature. As most of the chemical reactions are exothermic, normally heating occurs and if water is present hydrogen evolves. Dry direct reduced iron deactivates quickly in air but is still reactive if it comes into contact with moisture. Because of these characteristics, special requirements are necessary for safe storage, shipment, and handling. In an effort to improve this situation passivation techniques were and still are being developed. The paper discusses the properties of direct reduced iron, presents past experience with storage, shipment, and handling of MIDREX® Iron, a direct reduced iron material produced in the MIDREX® Direct Reduction Process, and evaluates benefits derived from different passivation techniques.

Jan 1, 1978

By Charles Stuart

A PAPER on this subject can cover but a limited range. A thorough visualization of the subject would contemplate a comparative analysis of haulage machines and batteries of various types; the relationship of the storage-battery locomotive to other types of mine haulage should be considered and limiting factors in each case should be carefully developed. This paper will briefly deal with these factors. So far as the writer has been able to determine, the first storage-battery locomotives for mine haulage were manufactured in 1897 or 1898 and were tried out in the Pocahontas coal field, but they were not sufficiently satisfactory to justify their continued use. Battery explosions were frequent and caused serious damage to the wiring, electrical equipment, and the clothing and bodies of the motormen. Sulfuric acid was used as the electrolyte. Experiments were then conducted with locomotives bearing reels of flexible cable through which connection between the motors of the locomotive and the trolley wire was maintained. At first, these reels were turned by hand. Later, the reels were revolved by contact with the wheels of the locomotive, being raised out of contact with the wheels, by a lever, when necessary. About 1902, the plan of operating the reel, by chain and sprocket wheels, from one of the locomotive axles, as is still the practice, was devised. The popular floating motor-driven reel had its inception in the Pocahontas fields prior to 1906. The maximum radius of operation of the reel-type locomotive is about 500 ft. (150 m.) from point of connection with trolley wire. This is ample for room work and certain entry work, but the need for a machine that would operate entirely independently of the trolley wire was so great that, with the development of the storage battery, renewed efforts were made to manufacture a successful storage-battery locomotive. About 1908, the gasoline locomotive was introduced. In spite of many objections to this type of machine for such work, the fact that hun¬dreds of these machines were purchased was proof of the need for a machine operating independently of the trolley.

Jan 1, 1922

By RUSSELL C. FLEMING

THE important advances that have been made of recent years in mining and milling methods and in mechanical equipment at mines need no re- telling, but there has been a remarkable growth in one type of equipment which has gone nearly unnoticed. That is the increasing use of storage-battery locomotives underground. Since the war the number of these locomotives and their field of use have increased tremendously; their growing acceptance represents an al- most complete reversal of opinion from an earlier period when they were generally looked upon as in- adequate for the strain of mine service. At the time when storage-battery powered units were first making their bid for recognition, the use of power in haulage had already passed through several phases; hand tramming, rope haulage, compressed air locomotives, even gasoline locomotives, had all been used, ending finally in the general adoption of the electric trolley locomotive for practically all power-haulage requirements. It was, and is, conceded that the trolley loco- motive met more adequately the varied and severe conditions of mine service than any previous type of haul- age unit. Subsequent developments have had to endure comparison and surpass in performance that type of haulage before changes would be considered.

Jan 1, 1930

By Jiann-Yang Hwang

Hydrogen storage is a critical issue for the hydrogen economy. Current storage technologies are not able to meet the combined gravimetric, volumetric, and system cost targets set by the Department of Energy. To solve the problem, the development of a new material - perhydride ? is proposed. Perhydrides are defined as materials that contain more hydrogen atoms in their molecules than conventional hydrides do based on the valence. This concept is supported by the versatile bonding capability of hydrogen and the recent discoveries in the chemistry of hydrogen clusters.

Jan 1, 2006

By E. J. Eisenach, Edward Matsen

AT the present time the Climax Molybdenum Co. is the largest molybdenum producer in the world and the operator of the largest underground mine in North America. It has grown steadily and rapidly since its beginning in 1917. Only 250,000 lb of MoS2 were produced during the first year from 1917 to 1918 when the company was formed. Operations were suspended shortly thereafter because of the lack of a market and knowledge of the uses of molybdenum. During World War I it was used as a substitute for some rare metals and for minor chemical purposes. After 5 years of intensive research and sales promotion, Climax metallurgists succeeded in finding proper applications for the newly discovered metal and the mine was reopened in 1924. Demand for molybdenum increased gradually and in 1930, 3.5 million lb of MoS2 were produced. In the meantime, research work for additional uses of molybdenum continued until it had established itself as one of the most important alloying elements in producing high quality steels. After the start of World War 11, from January 1942 to October 1953, 43 million tons of molybdenum ore were mined and 484 million lb of MoS2 were produced. Climax mine is located in Colorado, 100 miles southwest of Denver and 12 miles northeast of Leadville on the Continental Divide of the Rocky Mountains. The principal mine workings range from 11,170 to 12,000 ft in elevation. Topographically, it lies in the base of a large cirque that is surrounded by Mt. Bartlett to the north, Clinton Peak and McNamee Peak to the east and Ceresco Ridge to the south. This cirque opens to the west and to the Ten Mile Valley.

Jan 3, 1954

By Charles M. Cooley

In these troubled times free enterprise is maintaining vital molybdenum output, while expanding plant, and bringing in new low grade ore reserves, at Climax, the world's largest known molybdenum deposit. Climax Molybdenum Co. is putting $25 million into additional surface plant facilities and other millions into underground development. The expansion program to be operating by 1954 includes a new mining level, crushing plant, 4000-ft conveyor, milling units, by-products plant, and housing for 198 families. Completion of this program and low grade plant will add 10,000 tons per day to present capacity and several million tons to ore reserves.

Jan 1, 1953

By T. J. Cox

The Red River is located within the Sangre De Cristo Mountain Range in northern New Mexico. An approximate 12-mile segment of the river from the town of Red River to the village of Questa (Questa) includes several hydrothermal alteration zones. Alteration ?scars? formed as a result of rapid chemical weathering and physical erosion of pyrite-rich hydrothermally altered rocks. Storm water runoff from the scar drainages contributes metal-laden, acidic water to the river and creates a visible plume of discolored water in the river. Acidic runoff reduces the river pH from 7 to the mid 3s for at least 2 hours during large storms and the low pH water continues downstream. Runoff from scar drainages increases some metal concentrations in the river from below chronic ecological criteria to as much as two orders of magnitude greater than acute ecological criteria, and results in acutely toxic conditions for macro-invertebrates. A general improvement in the river?s water quality occurs downstream due to dilution from tributary inflow from non-mineralized watersheds, the natural buffering capacity of the river, and storm water controls at the Chevron Mining Inc. Questa mine.

Jan 1, 2011

By AIME AIME

THE outstanding event of the past month has been the conference in Washington of the representatives of about seventy-five of the leading national, regional and local engineering and allied technical organizations." Editorial-July Journal-The American Society of Mechanical Engineers. ?Prominent engineers from all parts of the country, representing more than 75 engineering societies, with an aggregate membership of more than 125,000, participated in the organization.? Editorial-July Journal-American Institute of Mining and Metallurgical Engineers. ?Civil, mechanical, electrical, mining, heating, sanitary, chemical, agricultural, marine, refrigerating, radio, fire protection, automotive, industrial and military engineers, as well as some architects and geologists assembled at Washington, D. C. to consider the advisability of organizing a national federation capable of bringing the united efforts of the entire membership to a focus on any problem of mutual interest." American Architect, June 23, 1920. ?"the object sought places it above any engineering gathering ever held." Editorial-American Machinist, June 17, 1920. "The youngest. profession has voluntarily accepted its responsibility in human affairs and is now reaching forward to a career of essential service." "This is .unmistakably the meaning of the Organizing Conference " Editorial-Industrial Management, July; 1920.

Jan 1, 1920

By R. D. Brown

"""A matter of serious concern to the mining industry in British Columbia""; this comment reflects the attitude of the Mining Association of British Columbia toward the proposed new B.C. Mineral Royalties Act. The proposed legislation, introduced by the provincial government in February and now being debated by the legislature, combines a basic 5% royalty on the selling price, less approved p1ocessing and transpo1•tation costs, of minerals produced in B.C. with an ""excess"" royalty of 50% of any price increases over a predetetmined base. Government estimates project annual revenues of $20 million from the new royalty structure. The accuracy of these figures has been contested by the mining industry. Based on current world prices for copper the industry estimates that the provincial revenues from this mineral alone may run as high as $140 million in 1974 and $150 million in 1975. The Mining Association has warned that the new royalties “threaten to become confiscatory""."

Jan 1, 1974

By J Miedecke

A metalliferous mine has operated at Storys Creek from the 1890s to 1979. Storys Creek drains from a pristine catchment and National Park and remains as the most degraded stream from historic mining in north-eastern Tasmania. It has been the subject of public concern since the closure, particularly at times of high rainfall such as existed in 1985 and 1986. The mine is located on the banks of the creek, which flows into a major river, the South Esk River, which is one of TasmaniaÆs largest rivers and important for recreational fishing and water supplies. For much of the life of the of the operations tailings were directly discharged into the creek, and in latter years stockpiled or very close to it. Little rehabilitation was carried out at mine closure. The result was erosion and subsequent deposition on the banks of the creek downstream. Direct emissions of adit water and the consequential emission of contaminated ground water to the creek continue to affect water quality. Contaminant loads discharging from the mine and tailings comprise 70% of the metal load in the catchment and are by far the largest single source. Acidity data suggested that the introduction of systems to introduce alkalinity could be effective in ameliorating the residual acid drainage impacts in the Storys Creek catchment. After a period of investigations and trials which proved their effectiveness, treatments adopted have included the following: relocation of tailings to a constructed and clay capped disposal area and rehabilitation of tailings area; crushed limestone addition to stream flows; crushed limestone addition to creek banks and exposed tailings; sealing of a drainage Adit; and construction of an anoxic drain to generate alkalinity to surface waters draining to old mine workings. These innovative treatments have resulted in a marked improvement in water quality draining from the area. The anoxic drain is believed to be one of the few, if any, which has been constructed to have generated high levels of alkalinity from clean waters and offers a solution to the clogging problems experienced in such drains in the past. Similarly, the use of crushed limestone in an active stream has proved effective in buffering acid drainage and removing metals from solution.

Jan 1, 2003

By Howard M. Wells

Investment in minerals development usually entails big financial outlays. which will remain at risk for a long time before the venture can begin to generate a return cash flow. Before 'committing himself to such a venture the investor would be wise to carefully examine the possible consequences of his exposure to risk. In this context risk is defined in multiple terms, which relate the magnitude of possible loss with the probability that such loss may occur--normally the probability will decrease as the amount of possible loss increases. The analysis of risk is an essential component of the decision making process, especially so in the case of low grade high tonnage mining ventures where a very real possibility exists that future unfavorable circumstances may lead to losses that could cripple or ruin even the richest corporation. Wells (1979) postulates a rationale for making the investment decision under uncertainty based on the comparison of two independent risk criteria: 1) the risk inherent in the venture represented by the negative portion of the cumulative distribution of the net present value (NPV), as derived by a stochastic evaluation procedure, 2) the limits of risk the decision maker is willing to accept, taking account of the financial capacity-of the 'firm to absorb various levels of future cash shortfall should the venture prove disappointing. The chance the investor would be prepared to accept can be expected to decrease as the amount of the possible shortfall increases. The limits of acceptable risk are-defined by a curve called the "LL-curve" which can be directly compared with the cumu¬lative NPV curve. A positive investment decision is implied if the limits of acceptable risk are not exceeded.

Jan 1, 1982

By Guilherme Guidugli

The hot blast stoves are a regenerative heat exchange system, accounting for 10 to 20% of the total energy requirement in an integrated steel plant, responsible for the supply of about one-third of the blast furnace heat input and responsible for a constant flow of hot air to the blast furnace, according to the required production. Because of their important role in the hot metal production, a stable operation and an appropriate combustion control is necessary. This paper aims to present the results of an investigation and modifications performed as an operating multi-furnace plant, as well as the parameters considered to ensure thermal equilibrium, improving in the stoves heating cycle.

Aug 16, 2017

By M Vavro, V Slivka, J èterba

In the course of the last ten years the development of the mining industry in the Czech Republic has been influenced by the pushing through of economic and ecological criteria. Due to this coal mining was ended in the whole series of the underground coal mines. These mines become the source of ecological and safety risks û methane leakage, surface deformation, etc. The way of solving of these problems is by stowing of underground spaces, and also surface fault basins with the help of mixtures produced from industrial wastes. The presupposition of this procedure is knowledge of prescriptions for production of the mixtures, and of the economic advantageousness of carrying out these activities. This contribution pays attention to the utilisation of power-gypsum as a raw material in the production of mining-construction materials.

Jan 1, 2003

By C. Hari Manoj Simha, J. Gholipour, M. J. Worswick

Due to the high pressures involved in the hydroforming process, friction and lubrication play an important role and can affect formability of the material. Tubes of A1Mg3.5Mn aluminum alloy, of 76.2 mm (3 inch) outside diameter and 2-mm thickness were considered in this study. Three kinds of lubricants, Al070, Hydrodraw711 and water, were applied to the tubes and tubes were hydroformed to burst in a square shape die cavity. The key process parameters were recorded during the tests. An in-house Gurson-Tvergaard-Needleman (GTN) damage-based material model, implemented in LS-DYNA, was used to model the process and predict the formability of this material. The applied axial loads and internal pressures recorded during the tests were used in the computations. The effect of different types of elements (solid and shell) with different constitutive models (von Mises and GTN models) in predicting the strain distribution is studied. The GTN damage-based material showed a good ability to capture necking and displacement histories in this process. Both predicted and measured results showed that the lubricant with lower coefficient of friction can effectively increase the comer expansion.

Jan 1, 2006

By Syed Haq, Kyle Optt, David Campo, Doug Anderson

Limitations on allowable levels of vibration from construction activities generally consider either annoyance or damage. While activities such as drilling and roller compaction primarily create annoyance, the major concern for blasting is usually damage. Many years of research have developed correlations between peak particle velocity and either threshold or structural damage. We emphasize the term “correlation” for two reasons. First, peak particle velocity is only a single-valued representation of a vibration waveform, and does not characterize it completely. Second, a given peak particle velocity by itself, even a particle velocity waveform, will not damage anything – strain does. Why not measure strain all the time? Strain is very localized, and can vary substantially over short distances, so choosing the appropriate strain measurement can be difficult. Measurement of strain is appropriate when either the behavior of a specific structural element is needed, or the overall response of a structure can be adequately represented by a well-selected strain measurement. We will discuss the appropriateness of both particle velocity and strain as deformation and damage descriptors, in general. We will also describe a specific case history, from a tunnel project in New Jersey, correlating strain with peak particle velocity. Finally, we will make recommendations for the choice of measurement type for some common situations.

Jan 1, 2004

By R. A. Sudisman, T. Yamabe, M. Osada

"Geological material can be subjected to some different loading conditions, mainly due to three inter-related physical processes which are mechanical, thermal, and hydrological. Freezing and thawing process of rock that occurs in sub-zero temperature condition may contain some or all those three physical processes depended on its initial condition. Those inter-related physical processes may lead the ground into failures. Therefore, understanding the physical properties such as deformation process of geological material under freezing and thawing condition is required for the artificial ground freezing projects and engineering construction activity in the natural cold region.In order to study the strain characteristic of rocks during freezing and thawing process, a series of freezing and thawing experiments of core samples of three different rock types and mortar has been conducted under varying temperature from -20 °C to +20 °C. Four core sample types are Sandstone, Granite, Tuff, and Mortar with 50 mm diameter and 50 mm height, which were naturally dried before the freezing-thawing experiment. Freezing-thawing experiment was conducted by submerging the vinyl covered core samples into a temperature-controlled liquid coolant box. Firstly, temperature of liquid (brine solution) was set at -20 °C so that the temperature of subjected sample was decreasing to as low as -20 °C. And then the temperature of brine was returning to initial room temperature after the coolant system was stopped. Strain gauge and thermo couple were attached on the core’s perimeter to measure strains and temperature changes.Sandstone and Mortar samples show relatively similar results than other two samples. Both presents linearly shrink with the temperature decrease and expand almost to its initial condition with the temperature increase. Granite shows less-linear strain-temperature relationship during thawing process, while the Tuff sample shows abrupt strain increase during thawing process on the temperature higher than +10 °C. Thermal expansion value of each rock types were obtained by fitting the major strain-temperature relationship on -19 °C to +10 °C temperature range. Overall, anisotropic deformation was observed on the entire samples and possible mechanisms for each hysteresis characteristic are discussed, which need to be confirmed by further experiments."

Jan 1, 2015

By D. K. Uko

In the stretch-bend or bending-under-tension test, a strip is rigidly clamped and restrained at each end and bent by central transverse loading using a radiused punch: The strip deflection at failure has been used as a measure of formability for high-strength low-alloy (HSLA) steels by other investigators. In this work, a detailed study is made of strains developing during stretch bending of an 80,000-lbf/ in 2 (552 MPa) yield stress steel using different punch radii. It is shown that toward the end of the process, the bending strains at both the inner and outer surfaces are tensile and suddenly increase at a rapid and approximately equal rate. The strain ratio in the failure region departs significantly from plane strain , even using a large width-to-thickness ratio of about 10. The effective fracture strains appear to be independent of bend ratio (punch radius/thickness) and significantly below the fracture s train in simple tension. Metallographic and tensile data were obtained for the subject material and, for one bend ratio, the effects on stretch-bend parameters of annealing both on this material and a. carbon steel were compared.

Jan 1, 1977

By Vasilis Androulakis, Caroline Gerwig, Zach Agioutantis

Mining operations that involve caving of the overlying strata are designed so that caving occurs in a controlled manner by progressive overburden failure. However, there are many cases where the overlying strata bridge over the caved area for longer periods than anticipated and desired. As the caved area expands with the advance of the mining panel, excessive amounts of energy accumulate in the roof strata which will be rapidly released when the overburden eventually fails.