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By D. Harrington

Every few weeks United States newspapers of 25 or 30 years age ran scare-heads telling of some mine disaster, which was a first-page attraction for a day or two and then was forgotton until another disaster occurred a few weeks later. Interspersed with these disasters were the so-called sniping mine accidents, causing the death of one or two mine workers. The summation of all types of mine fatalities usually exceeded 3,000 a year. In the period 1906-10, inclusive, there wore 84 major explosion disasters (or about 17 per year) in united States coal mines; the fatalities resulting from those disasters numbered 2,388 for the 5-year period. These frightful catastrophies helped to cause the total number of fatalities in our coal mines for the 5 years (including the fatalities from major explosions) to reach the enormous total of 13,288, an average of 2,658 per year. In addition, some hundreds of other typos of mining accidents swelled the annual fatality list to upwards of 3,000. This admittedly deplorable condition created so much Nation-wide comment that Congress was impressed with the necessity of having something done by the Federal Government with a view to trying to halt at least sonic of the excessive loss of life in our mines; in consequence, the Bureau of Mines was created and began to function in July 1910.

Jan 1, 1935

By Anthony Spearing

There are approximately 68 million rockbolts installed annually in underground coal mines in the USA (Tadolini and Mazzoni, 2006). The most utilized is the passive fully grouted resin rebar bolt, which constitutes almost 90% of the primary support in US underground coal mines. Resin-grouted rockbolts are a very effective and safe support, but their performance still needs to be further optimized and improved. This paper investigates their performance and suggests operating conditions to optimize the performance of resin-grouted rockbolts. In addition, this paper discusses a small-scale test that can also be used to evaluate the performance of rockbolts that is quicker, easier, and less costly than short encapsulation tests.

Jan 1, 2014

By Y. S. Li

The life cycle assessment method is applied to investigate the environmental impacts of cop-per-slag and copper-ore concentration process. Some environmental load data of copper production are obtained. The result indicates that damage level of human health, ecosystem quality and re-sources respectively is 0.174, 0.0203, 0.246 in the copper-slag concentration and 0.112, 0.0136, 0.299 in the copper-ore concentration. Environmental impact of copper-slag production (0.44) is more than that of copper-ore production (0.42), but can meet the environmental protect demand. With domestic copper concentrate supply gap enlarging, recovering copper from slag will lead to a significant improving of resource utilization and development of circulation economics.

Jan 1, 2014

By Steven G. Jansto

Nearly one third of the globally produced structural flat and long structural products are in the 0.11 to 0.16% carbon range. By definition, numerous steelmakers globally define this approximate carbon range as peritectic in their melting grade family within their organization. The metallurgical consequence is the result of numerous global structural specifications which allow carbon to wide carbon ranges resulting in quality issues. For example, such specifications as ASTM A588 set no minimum carbon and a 0.15 to 0.19%C maximum depending on the specific grade designated within the specification. This peritectic region is specifically challenging in production compared to less than 0.10%C because of solidification issues and a higher propensity for slab or billet cracking during continuous casting. During hot rolling, rejects and/or deviates are increased as well. The relative steelmaking operational cost of production is compared between peritectic and non-peritectic carbon compositions for a given specification.

Aug 17, 2017

By Xianjun Lyu, Junxiang Wang, Peng Wu, Minjie Lian

"In recent years, the efficient cementation of mine tailings is a new way to manage mine solid wastes. The traditional cement materials have a slow setting time, large dosage and poor cementation strength for fine aggregate such as mine tailings. Therefore, the preparation of new type cementitious materials for the cementation of fine tailings has great potential in the treatment of mine waste solids. The paper mainly focuses on exploring the critical factors affecting the cementing performance of granulated blast furnace slag and its performance in the cementation of fine aggregate. Results indicate that the fineness of slag has a significant effect on its cementitious activity and Portland cement clinker has a better stimulation effect on the cementitious properties of slag than lime. And, anhydrite has a better early stimulation effect on the cementitious properties of alkali-activated slag compared to semi-hydrated gypsum and dihydrate gypsum. According to a series of tests on the cementation of fine iron tailings, the optimal ratio of slag, Portland cement clinker and anhydrite is determined as 60:30:10. Compared with P.O 42.5 ordinary Portland cement, the new slag based cementitious material shows much better cementing performance on fine tailings sample. Under the dosage of 12%, the compressive strength of fine tailings mortar using slag-based cementitious material in 3 curing days is increased to 168% that of using P.O 42.5 ordinary Portland cement, while the compressive strength in 28 days curing period is increased to 194%."

Jan 1, 2018

By Joseph M. Keane

A number of innovative techniques exist for solving heap leaching problems in special situations. Some of these techniques have been successfully applied and others await an opportunity for application. Discussions in this paper will deal with gold heap leaching under severe thermal conditions, in tropical rainfall circumstances, in the absence of fresh water, and in other situations removed from the ordinary. CLIMATIC CONSIDERATIONS The success or failure of precious metal dissolution operations may be strongly dependent upon proper attention to the influence of climate. A few examples are given in the following paragraphs.

Jan 1, 1987

PAUL. D. MERICA, Bayonne, N. J. (written discussion*)..-The mode of intercrystalline oxidation which the authors" have so well observed and described is characteristic of nickel that has been exposed' to: the action of an oxidizing atmosphere at higher temperatures, such as, those at which; it is annealed or heated for rolling or forging. Oxidation under such conditions proceeds inward from the surface along the, crystal boundaries' producing a net-work, probably of oxide; which causes a very brittle condition of this surface material. This, in turn, generally results in surface cracking and checking during further, rolling and a defective sheet or other product is produced. An example of this is shown in Fig. 2, which shows the surface, of a badly surface-cracked sheet of nickel produced by incorrect heating con-ditions. A cross-section of this sheet etched with nitric acid is shown in Fig. 1, which reveals the intercrystalline oxidation network adjacent to both surfaces.These layers are so brittle that it is not possible to deform them by rolling without severe cracking along these lines or, planes of weakness. The best, and possibly only, remedy for this condition lies in its prevention by the maintenance of a neutral soft flame for heating and annealing nickel during the entire course of its manufacture. I should like to suggest that, those making microscopic investigations of nickel and nickel-rich alloys try the use of acetic-acid .solutions of nitric acid for etching these metals rather than aqueous solutions, of nitric acid. I have found that a solution containing 50 per cent. nitric acid, from 25-45 -per. cent. acetic acid, and from 25-5 per cent. water gives excellent results with. Wrought and cast nickel and Morsel metal and superior results to those obtained with nitric acid, alone. The acetic. acid seems to inhibit the passivity that nickel often assumes toward nitric acid and much more uniform etching may, be obtained. The proportions of nitric and acetic, acid may be varied somewhat from those given without mate-rially altering the quality of the etching, although without any distinct improvement in it.

Jan 12, 1919

By K. E. Prince, S. Burling, R. J. Ring, M. K. Maley, W. R. Taylor

Vanadium occurs as a component of carnotite, which commonly occurs in calcrete type ores, and in association with uranium in some sandstone-hosted deposits. Increasing demand for vanadium, which is used in high-strength steel and Vanadium Redox Flow Batteries (VRFBs), is offering some uranium producers a potential option for by-product vanadium recovery to improve project economics at a time when uranium prices are low. This paper presents the results of recent optimisation studies on the Bigrlyi deposit for the recovery of both uranium and vanadium. The impact of carbonate leaching conditions on uranium and vanadium extraction from a range of carnotite-in-calcrete ores is also examined, with vanadium extraction limited by the proportion of non-carnotite vanadium present in the ores. The findings are particularly relevant to developing projects as results show that elevated vanadium content in ore does not necessarily equate to a high vanadium extraction in leach.

Jan 1, 2020

By Iain B. Mackenzie

In 1997, a thin layer of Microtherm Microporous Insulation was used to replace fireclay brick behind the magnesia/chrome working lining in #5 refining furnace at BHP?s San Manuel AZ smelter. A 23°C reduction in shell temperature was obtained, together with a large increase in the working capacity of the vessel. There was no sign of metal penetration as a result of the increased insulation. Following these highly favorable results, BHP have introduced this product into all of their refining furnaces.

Jan 1, 1999

By Kazuyuki Kikuta

MMAJ, a govemmental organization in Japan, has carried out a 4 year project for the development of the decontamination and metals recovering technology for the fly ashes from municipal waste incineration. Heavy metals (zinc, lead and copper) are recovered as raw materials for the non-ferrous metals production, without formation of any waste materials to be disposed. More than 500 thousands tonnes a year of fly ashes generation from the municipal waste incineration has been one of the main social issues in Japan, because most of them need to be disposed to the registered areas after decontamination, and occupy 5% of the municipal wastes disposed. The segregation, flotation and chemical process are applied to the treatment of the primary fly ash from municipal waste incineration, and MF (Mitsui-type blast furnace) Process after the chlorine removal to the secondary fly ash. The main results of experiments are -About 90% of heavy metals, zinc, lead and copper, can be recovered from the primary and the secondary fly ashes to the products for the non-ferrous metals production. -Both of the leaching residue from the primary fly ash treatment and the slag from the secondary fly ash treatment can be used as a raw material for the cement production, meaning that the decontamination technology for the ashes without the landfill has been established. -Dioxins in the primary ash can be decomposed satisfactorily, and the dioxins content in the segregation furnace gas is less than O.lng-TEQ/Nm3 without any gas cleaning system

Jan 1, 2003

GREETING Hail! Hail! the Coal Miner, Damn the operator, damn the operator, Hail! Hail to mining coal We'll tell 'em how to run the mines. Oh, we'll send out a questionnaire And we'll quiz 'em, we will razz 'em for fair, We'll ask about the profits and order them to stop it Tell the world we're going to stop right there. Hail! Hail! etc. NASH AND PRYDE Tune, "Gallagher and Shean" There are two mining men, the best I've ever spied, One is Mister Harry Nash, the other Mister Pryde. When these two fellows meet it surely is a treat, The things they do, and the things they say, And the funny way they greet. Say, Mister Harry Nash, Oh, Mister Harry Nash, Tell me what's on your mind this evening, Mr. Pryde; I have heard an awful lot of that steep coal mine you got, And I wondered if some one had up and lied. Oh, Mr. Pryde, Oh, Mister Pryde, It's so steep it seems to lie upon its side. If it were steeper than it is, it would put us out of biz, Absolutely, Mister Harry Nash, positively, Mr. Pryde. Oh, Mister Harry Nash, Oh, Mister Harry Nash, Somebody said that at this new mine you've begun 'Fore you mined a lump of coal, had to burrow like a mole, And of rock you dug out many a million ton. Oh, Mister Pryde, Oh, Mister Pryde, I hate to think of all the dough I supplied. I believe the Moffat Tunnel bore won't cost a single dollar more I don't think so Mister Harry Nash, I agree with Mister Pryde. PARTING Tune, "Leave Me With a Smile" Though a sea of strikes and low price squabbles, Follow us the while; Once a year we gather just to show them whether We still wear-a smile; Rocky music coal still packs a barrel full Of timely fun sans guile, Rocky Mountain Institute can follow such And smile its yearly smile.

Jan 1, 1924

By Luana Ferreira de Carvalho, Aurelio Manço Garcia, Gustavo Sampaio Lopes, Jose Silvio Corsini, Davi Bastos Martins de Oliveira

The Enaex Mining Technical Solutions (EMTS) team, in partnership with the Anglo American Iron Ore Brazil drilling and blasting team, has developed a study aiming to optimize the blast design applied at the Minas-Rio project. The study consists of modeling the dynamic behavior of one lithological domain to determine the best configuration of drilling pattern, charge configuration, timing and sequencing of the blast designs applied at the mine in this particular rock.

Feb 1, 2020

By S. Bentley

"Everyone has a general idea what mixing means, but describing the mixing process is not so simple. The objective of any mixing process is to distribute and blend the materials with different characteristics, different quantities as evenly as possible resulting in a homogenous mixture. Introducing proportional movement with the optimal intensity into the materials achieves effective homogeneous mixing results. A simple one directional movement with inadequate acceleration of the materials would obviously not achieve the same mixing results. This would be more like stirring than mixing. The amount of relative movement that is introduced is a decisive factor. Circumstances for successful mixing involve distribution of all materials, and achieving the highest probability that all recipe particles located in a specific position at the beginning can be found at any random location in the mixing chamber at the end of the process. This is the only way to ensure that a consistent result is achieved every time mixing is repeated.THREE-PART CYCLE The mixing cycle occurs in three phases; charging the mixer, the mixing process, and discharging. The sequence in which the individual materials to be mixed are filled into the mixer can have a huge impact on the efficiency of the mixing cycle. The mixing cycle overlaps the charging process and the discharge cycle follows the mixing cycle. To achieve optimum results, effective discharging methods should be taken into consideration to avoid risks of segregation. Costs for energy and wear should be as low as possible and finally, it is very important that the mixing cycle takes place as quickly as possible. In concrete or paste backfill production, selecting the best mixing technology is crucial for both the quality of the final product to be blended and the efficiency of the production process. The optimum mixing system is one that rapidly disperses all ingredients evenly throughout the mixing trough and completely surrounds all the course or fine aggregate particles with the slurry cement particles. Specific for paste production it’s the mixers job to also break-down unconditioned tailings to achieve consistent paste viscosity or measured spread. Many paste and concrete formulas also involve small quantities of chemical additives which also must be evenly distributed effectively. The time required per mixing cycle as well as the costs of energy, wear and maintenance will determine the economy of the concrete production."

Jan 1, 2015

By J. J. Van Rensburg

The commissioning of a test facility for the calibration of anemometers by J. J. VAN RENSBURG (Student Member). After the erection of a commercially produced open-jet wind tunnel for the calibration of the anemometers used in mine ventilation, the wind tunnel was calibrated for routine use. There is a choice of five orifice plates. which, together with a variable-speed fan, can give a measurable range of air velocities in the test section from about 0,05 to 35 m/so The orifice plates were calibrated against a standard pitot tube, and it is now necessary only to measure the pressure drop across an orifice plate and to read off, from a set of graphs, the true outlet velocity in the test section. The paper describes the underlying theory and the test results.

Jan 4, 1975

By Arash Saeidi-Rashk-Olia, Dunja Peric

Energy piles are gaining increased popularity due to a growing demand for clean energy. To further advance the understanding of soil-structure interaction in energy piles, recently-derived analytical solutions have been implemented to investigate the impact of stratigraphy on the soil-structure interaction. This was accomplished by comparing the measured and predicted head displacements, axial strains and stresses in an energy pile embedded in the actual homogeneous and layered soil profiles, as well as into synthetic homogeneous soil profiles. The analytical solutions for homogeneous soil profile captured the smooth experimentally observed response versus depth very well. In the case of a layered soil profile, the corresponding analytical model was capable of capturing nuances in trends of axial stress and strain versus depth at the interface of different layers. The analytical predictions for the layered profile appear to be slightly less accurate than for the homogenous profile. The experimental data obtained from the layered profile appear to be a bit more scattered than those from the homogeneous profile. In the former case, the interplay of the individual soil layers with the pile occurs while maintaining the continuity of the pile stress and displacement at the interface of different layers. The response throughout each layer of the layered profile is quantitatively different than the corresponding homogeneous response. Nevertheless, qualitatively the response throughout each layer of the layered profile is similar to the response of the pile embedded in the corresponding homogeneous layer.

Sep 8, 2021

By Michael Stanwood

Project feasibility no longer involves just technical and economic viability-today's feasibility study must include environmental, regulatory, and political considerations as well. While the US now appears at least somewhat committed to developing synthetic fuels, including oil shale, it is the environmental issues, rules, regulations, and guidelines that will play the major role in determining the timing, magnitude, and overall scope of synfuel development in the coming years. The key environmental obstacle affecting oil shale development is uncertainty. Although oil shale may be the most environmentally studied "new" technology in the world, little is known with much degree of certainty about potential environmental consequences of one full-scale commercial facility, or the effects of a massive development effort in a relatively pristine and sparsely populated area. Other primary environmental uncertainties include: • Environmental compliance costs and their effects on investment decisions; • The reliability and acceptability of anticipated pollution control technologies; and • The confusing, time-consuming environmental regulatory framework, which requires more than 100 permits, clearances, and reviews before development occurs. This discussion will focus on the latter uncertainty, and will describe he current status of potential constraints to oil shale industry development in five areas: water availability; water quality degradation; air quality degradation; reclamation and spent shale disposal; and community impacts.

Jan 1, 1981

By Richard Moldenke

One of the gravest problems of the iron foundry today is the accumulation of sulfur in commercial scrap and its effect on the castings made therewith. The ordinary jobbing castings today show a sulfur content of 0.18 per cent;, and occasionally as high as 0.22 per cent. The product of the foundry during the war is undoubtedly to blame for this rapid increase and conditions will become worse as the millions of tons of gray-iron castings of the war period return to the foundry in the form of commercial scrap. In the ordinary cupola remelting of pig and scrap, at least 0.02 per cent. sulfur is taken up; often double that amount. The high cost and difficulty of obtaining pig iron during the war period compelled the use of considerable scrap in the mixtures; frequently charges containing 90 per cent. of bought scrap were melted. Naturally the sulfur content of the castings increased. Until the advent of the basic-hearth electric furnace, the only method of holding the sulfur within reasonable limits was to use high percentages of pig in the foundry mixtures. Pig iron seldom contains over 0.05 per cent. sulfur, if well made. With pig iron forming 60 per cent. of the charge and the gates, runners, rejections, and bought scrap the other 40 per cent., the sulfur content of the castings can easily be held down to 0.10 per cent. Pig iron, however, costs more than scrap even when melting loss differences are considered, hence as small a percentage as possible will be used. The recent advance in knowledge of rational melting and the consequent reduction in losses directly due to oxidation of the metal and cold iron, has permitted the acceptance of castings with a much higher sulfur content than formerly. The steel industry also is seeking to determine how high sulfur may go with safety. In the iron foundry, however, there is the danger of a low cupola bed or an unduly retarded air-furnace heat, with the consequent raising of the freezing point of the metal and segregation effects resulting from high sulfur with insufficient manganese. The iron foundryman must, therefore, have a means of correcting his

Jan 1, 1922

By Richard Moldenke

One of the gravest problems of the iron foundry today is the accumulation of sulfur in commercial scrap and its effect on the castings made therewith. The ordinary jobbing castings today show a sulfur content of 0.18 per cent;, and occasionally as high as 0.22 per cent. The product of the foundry during the war is undoubtedly to blame for this rapid increase and conditions will become worse as the millions of tons of gray-iron castings of the war period return to the foundry in the form of commercial scrap. In the ordinary cupola remelting of pig and scrap, at least 0.02 per cent. sulfur is taken up; often double that amount. The high cost and difficulty of obtaining pig iron during the war period compelled the use of considerable scrap in the mixtures; frequently charges containing 90 per cent. of bought scrap were melted. Naturally the sulfur content of the castings increased. Until the advent of the basic-hearth electric furnace, the only method of holding the sulfur within reasonable limits was to use high percentages of pig in the foundry mixtures. Pig iron seldom contains over 0.05 per cent. sulfur, if well made. With pig iron forming 60 per cent. of the charge and the gates, runners, rejections, and bought scrap the other 40 per cent., the sulfur content of the castings can easily be held down to 0.10 per cent. Pig iron, however, costs more than scrap even when melting loss differences are considered, hence as small a percentage as possible will be used. The recent advance in knowledge of rational melting and the consequent reduction in losses directly due to oxidation of the metal and cold iron, has permitted the acceptance of castings with a much higher sulfur content than formerly. The steel industry also is seeking to determine how high sulfur may go with safety. In the iron foundry, however, there is the danger of a low cupola bed or an unduly retarded air-furnace heat, with the consequent raising of the freezing point of the metal and segregation effects resulting from high sulfur with insufficient manganese. The iron foundryman must, therefore, have a means of correcting his

Jan 1, 1922

By M. Muinonen, R. Pandher

Royal Nickel Corporation is developing the Dumont Nickel Project, a large nickel sulphide deposit located near the town of Amos, Québec. The nickel occurs as pentlandite, heazlewoodite, and awaruite. The relatively low grade ore can be processed to a very high grade nickel concentrate, containing 29% Ni. The absence of copper and precious metals in the ore renders this concentrate amenable to processing by dead roasting in a fluid-bed roaster and smelting in an electric furnace to produce ferronickel for sale to stainless steel producers. Laboratory test work and conceptual engineering design was completed to demonstrate the amenability of Dumont concentrate to produce ferro-nickel.

Jan 1, 2015

By V. C. Smith

Reliable and detailed statistical data available for Kentucky, Ohio and West Virginia are the most meager and unsatisfactory of any of the producing states. Detailed histories and statistics are available for only a few pools. The antiquity of these pools, loose nomenclature, particularly where several names are applied to the same pool or various parts of the pool or a new namsed when the pool was rediscovered, made the collection of accurat historical and statistical data almost impossible. So many of the data reported are unreliable that a breakdown by pools or even by counties, until more accurate information is available, would lead to gross errors. Rather than perpetuate inaccuracies, we have endeavored to go to original sources wherever possible, sift these and provide data that may serve as an incentive and basis for future work. The necessity for accurate information is thoroughly recognized by the operators, particularly because of the effect of recent government regulations and request? for data in connection with the preparation of the various codes a pending legislation. Producers, both major operating companies and individuals, . freely given their time and assistance in the compilation of these data. Valuable information was obtained from tax records, rate cases, statistics published by the oil and gas publications and the Bureau of Mines. So many individuals cooperated in the preparation of these data that individual credit cannot be given. Undoubtedly many errors will be found. Some of the data are open to controversy, and many have been omitted in the hope that new information of a more reliable character may become available. Other omissions are due to an inability to contact the proper individuals, many of whom are no longer connected with this industry. Pennsylvania grade crude sold in 1933 for the lowest price since 1895. Gas production could not find sufficient new markets to fill the void left by industrial stagnation. In the gas industry, where the market price is fixed by contract, uncertainty persisted because of impending legislative action affecting both taxes and utility rates. As a result of these factors and a lack of new money, drilling was restricted to a new low. The lifting of proration toward the end of the year in the Pennsylvania

Jan 1, 1934