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By C. E. Augustine, B. A. Landry, P. Nicholls

"Wien bituminous coal is burned in a hand-fired up-draft boiler used for heating purposes it has a decided tendency to produce smoke. A design of furnace and a method of firing and attendance that are satisfactory for fuels low in volatile matter, as anthracite or coke, are not necessarily Satisfactory for bituminous coals. It is therefore becoming common practice to use a special design of furnace for bituminous coals, in order to facilitate the combustion of the volatile matter and soot. This is done by (1) providing a larger combustion space to give more time for the combustion, (2) construction that will produce a better mixing of the gases and secondary air supplied over the fuel bed, or (3) keeping the gases at a higher temperature by preheating the secondary air, as may be done by surrounding them with refractory surfaces, or causing them to pass through a fuel bed of hot coke. A furnace may be built to use any or all of these methods of smoke prevention.In Bureau of Mines Technical Paper 303, Blizard5 and others give tests on a large heating boiler when burning coke, anthracite, and bituminous coal. Certair alternative furnace arrangements were used, but there was no material change in the furnace design for the various fuels. Since that time the manufacturer has made modifications in design to adapt it for use of bituminous coal, and additional tests have been made to determine how this change affected the production of smoke and the efficiency of the boiler."

Jun 1, 1929

By T. Cienski

The paper presents and discusses the results of a detailed study conducted on the subject of energy consumption in the comminution of industrial minerals. The study was based on pilot circuit testing, plant operating data collection, detailed equipment data and literature research. The areas covered by investigations include: high efficiency classification; air classifiers for cement grinding circuits; grinding aids in dry grinding: dry grinding circuit, control based on particle size measurement. Results obtained indicate a large potential for the reduction of energy consumption, in particular in the traditionally high cement clinker grinding circuits. Better classification techniques and correct application of grinding additives can significantly reduce power used per ton of product and also substantially increase grinding circuit output.

Jan 1, 1990

By R. K. Borden

Rio Tinto is committed to proactive mineral waste and acid rock drainage management. Corporate requirements are closely aligned with the GARD Guide principles of early geochemical characterization and prediction followed by selection and implementation of management strategies to prevent or minimize ARD. Each operation is required to design and implement an ARD and Mineral Waste Management Plan. Successful implementation of the plan requires commitment at all levels of the company, from senior management, to geologists, mine planners, environmental staff and equipment operators. Examples of the successful integration of ARD management strategies into mine operations are cited from several mines.

Jan 1, 2011

By S. F., French

IN reviewing the design of the ore haulage system for the Morenci project, the reader should bear in mind that the railroad and its equpiment cannot be considered as an independent railroad provided only for the purpose of transporting ore from one point to another, but as an integral part of the operation which begins at the electric shovels loading ore at the mine, and ends where the ore, after having been crushed in the primary crushing plant, is deposited in the bins at the secondary crushing plant. Obviously then, the problem consisted of designing a system that would function to the best possible advantage in complete co-ordination with the other units.

Jan 1, 1942

By P. Mendoza, R. Siwale, H. Amini, R. Silva, M. Richards, V. Ngcoza, D. Rivera, C. Canaza, R. van Reenen

Development of a realistic flotation model to predict its performance is of paramount importance to the processing plant and operators, a model that accounts for predictive and no-predictive maintenance simulating individual equipment downtime and the effect of it in the metallurgical performance on the flotation bank with final recoveries and grades has a huge advantage on optimizing the flotation circuit/bank in terms of mechanical and metallurgical side. The Model was developed in a dynamic environment that allows for a better and more realistic simulation of the flotation bank. The maintenance model accounts for the Failure rate, Mean Time Between Failures (MTBF), Mean Time to Failure (MTTF) and Reliability (R(t)) those characteristics are combined to a multi-compartment process model that consists of a slurry recovery model, two options of froth recovery models, entrainment and carry capacity as a final check for the system. In addition to the maintenance and process model, a dynamic dart valve model was added to the simulation in order to have a realistic model to control the slurry level at the flotation cell. The paper goes over a study case for a current flotation operation trying to explore all the elements and the simulator to optimize the Rougher flotation bank.

Mar 2, 2022

By Arno C. Fieldner

In view of the widespread interest in the production of synthetic liquid fuels from solid and gaseous fuels to supplement declining reserves of petroleum, and the many requests that are now being received for information on the subject, this bibliography of Bureau of Mines contributions has been compiled. In addition to the publications issued by the Government in printed or mimeographed form, references are included to articles written by the Bureau staff for the technical press and to cooperative reports of work done jointly with States, colleges, and industries. References are given under each section in chronological order. Bureau of Mines bulletins, technical papers, and Minerals Yearbooks are printed and are obtainable at the prices indicated from the Superintendent of Documents, Government Printing Office, Washington 25, D. C. If no price is given, the publication is out of print. The price of entire volumes of the Minerals Yearbook or of reprints of certain chanters may be obtained upon request. Any orders or remittances in payment for these publications should be cent directly to the Superintendent of Documents and not

Jan 1, 1945

Over the last 15 years working in the mining, construction and extractive industries, one of the areas that has always concerned and at the same time drawn the author to it is the application of drilling and blasting in the underground development mining and civil construction tunnelling fields. In that time, the author has come across many drives and tunnels that are larger than design or badly damaged in the perimeter or both. When the question is asked as to why this is the case, the reply is generally æthatÆs the way it is and always has beenÆ. Sometimes it is blamed on bad ground, bad drilling, bad explosives, bad initiation or just plain bad. Most operators build a dilution factor into development and tunneling costs as an acceptance of overbreak and similarly pattern bolt everything to overcome excessive perimeter damage. This paper will attempt to unravel some of the mysteries behind perimeter drilling and blasting in underground drives and tunnels and discuss methods to reduce overbreak and therefore reduce costly dilution and to minimise perimeter damage which in turn will allow more cost-effective ground support. It should not be assumed that better drilling and blasting alone would automatically allow an operation to reduce ground support. The operator must still æreadÆ the ground and its characteristics in order to ensure sufficient ground support is placed to allow the operation to progress safely. This paper will not go into the intricacies of bolting, meshing, shotcreting, concreting and other ground support, but it will use indicative costs for the primary areas of drilling, explosives, excavation and labor to show the magnitude of cost-efficiencies which can be obtained through improved drilling and blasting applications. Drill and blast remains the most flexible and cost-effective method of underground excavation as long as it is applied safely and effectively.

Jan 1, 1999

By Douglas Glenn Stalheim

Production of structural steel with a minimum yield strength of 700 Mpa produced as hot rolled coil has become increasingly popular due to cost considerations when compared to quench and temper equivalent product. This grade when produced as hot rolled coil requires the use of microalloy precipitation strengthening mechanisms. This is typically a combination of niobium and titanium microalloys. While the metallurgical concept of structural steel precipitation strengthening mechanisms has been well researched and published, actual implementation into the production process can be very challenging. In addition to achieving a minimum yield strength of 700 Mpa, in many applications additional mechanical property attributes of formability as measured by hole expansion testing along with low temperature toughness properties are now required. Achieving a balance of all the mechanical properties in a stable and repeatable performance in production using microalloy precipitation strengthening mechanisms further increases the challenges. This paper will discuss the metallurgical/process strategies required to successfully produce 700 Mpa minimum yield strength hot rolled structural steel coil. In addition, the role and goals of both niobium and titanium in this product design will be presented.

Oct 30, 2017

By Ralph H. Espach

Wyoming contains many petroleum and natural-gas fields, and more than 250 geological structures have been mapped; however, only about 85 have been found (July 1938) to contain petroleum or natural gas, or both, in commercial quantities. To January 1938 approximately 434 million barrels of oil and 915 billion cubic feet of gas have been produced, and it was estimated that proved oil reserves in Wyoming amounted to 300 million barrels.' The Salt Creek field, the largest in the Rocky Mountain area, alone has produced 64 percent of the State's oil and 46 percent of its gas. This field ranked thirteenth among the producing fields of the United States in total cumulative production as of January 1, 1938. On this basis it ranks with the Kern River and Huntington Beach fields of California and the Butler County fields of Kansas. The Salt Creek field has declined in relative importance; in 1937, while still the largest oil-producing field in the State, it produced 31 percent of the oil and 11 percent of the gas extracted from all wells in Wyoming.

Jan 1, 1941

By Cleo Griffith Rall, D. B. Taliaferro

The method for determining oil and water saturations described herein has been used successfully for several years in the core laboratories of the Bureau of Mines. The apparatus constructed according to the original specifications has proved very satisfactory; in fact, it has been widely adopted by core laboratories throughout the petroleum industry. The writers have found that the method gives reproducible results, the degree of accuracy depending largely on the attention to details given by the operator. The relative importance of these details of procedure and the design of the apparatus are discussed in this report. In September 1940, the Bureau of Mines published a report describing a method used in its laboratories for the determination of the water content of oil-field cores. The procedure was essentially the same as that adopted by the American Society for Testing Materials for the determination of the water content of petroleum products, although the apparatus and technique were altered slightly to increase the precision of the method and to adapt it to the characteristics of the material to be tested. The report also contained a description of the method used at that time in the Bureau’s core laboratories for measuring the oil content of a core, utilizing the sample on which the water-saturation determination had been made. The procedure involved the transfer of the weighed sample, from which the water had been distilled and measured, to a Soxhlet extractor and the removal of the remaining oil by means of a suitable solvent. Soon after the report was published, the water-determination apparatus described therein was modified so that both the oil and water contents of a core sample could be determined simultaneously. This method, which has been described by Yuster, is now widely used throughout the industry.

Dec 1, 1946

By Paul R. Terry

This paper presents a brief picture of the quality of coal produced in Eastern Canada for use in thermal generating stations. It describes, in particular, the characteristics of coals burned in six power plants -two in New Brunswick and four in Nova Scotia. Each station is dis-cussed in turn, and comments are made on the coals used therein with regards to origin and physical and chemical properties affecting station operation. A table of coal data shows, at a glance, the wide variation in the quality of coals received by these stations from producers in New Brunswick and Nova Scotia. "The promotion of improved coal quality for thermal generation can benefit our national economy." T HIS is the opening statement in a paper which was presented by Mr. D. A. Pirttinen at the Coal Division's Toronto meeting in April, 1960. In bringing the power engineer's viewpoint to the coal producers' attention, Mr. Pirttinen made a survey of utility steam plants operating in Canada, and the results of this survey formed the basis for his paper, which he titled: "Generating Station Coal Quality.

Jan 1, 1965

By R. E. Fanning

"IntroductionThe Aluminum industry is one of many materials industries which strive to make their material the preferred choice for large volume products. In some applications one material has a natural advantage over others, but more frequently several materials compete with one another, each providing one or more advantages and some trade-offs. Customers may design their product with several objectives such as minimum system cost, maximum customer appeal or maximum manufacturing flexibility, choosing materials which best combine cost and performance. In such markets it may become necessary for a material supplier to enhance the attractive features of the particular material to outweigh its disadvantages.It is difficult, if not impossible, to predict how various materials will evolve. Technological breakthrough, government regulations, material availability or sociological issues may redefine the balance between competing materials. In spite of some uncertainty regarding the competitive position of competing materials, there is little doubt that unrelenting pursuit of product quality improvement and cost reduction are essential to future viability of the aluminum industry. It is the intent of this paper to identify some areas where technological improvement would be beneficial. Thus this paper is a collection of briefly described problems that will hopefully stimulate the thoughts and research required for knowledge based solutions. Rolling ProcessA particular example is the beverage can industry where aluminum, steel, glass and plastics vie for a share of the m.arket. The high cost of aluminum relative to steel or glass requires minimizing the amount of metal per can. The high intrinsic value of aluminum has led to extensive recycling of cans although net metal cost is still higher than that of the competing materials. Intensive engineering of the beverage can led to improved design and better understanding of material requirements. These improvements permitted substantial reduction in sheet thickness over the past decade. The downward trend in metal thickness for beverage can sheet is shown in Figure 1."

Jan 1, 1988

By K Jupp, T J. Howard

Cliffs Natural Resources Pty Ltd (CNR) operates iron ore mines in the Koolyanobbing region of Western Australia, about 50 km north of the town of Southern Cross. Ore is trucked from three geographically isolated sources to the crusher at Koolyanobbing, where it is blended before and during crushing. Lump and fines products are produced and railed to Esperance for ship loading and export to Asian customers. CNR is examining alternative processing paths, from mining to ship loading, with the aim of improving efficiency and reducing costs. Modifications to the system must be consistent with potential future expansions and maintain the low inter-shipment grade variability on which CNR prides itself and has built a strong relationship with its customers. In searching for the optimum process design, many options from mine face to ship loading must be evaluated and compared. Pilot plant studies are infeasible, while complex mineralogical interactions, competing goals and numerous possible system configurations limit the applicability of theoretical analysis. It was therefore concluded that simulation modeling would provide the confidence to take the next step into production trials. This paper describes techniques applied at CNR to simulate grade variability resulting from potential process design changes. The simulation models are easily run Excel-based modules, with each module representing a different part of the process. The modules use extensive Visual Basic macros driven by Excel's user-friendly interfaces. Presentation of the results is enhanced by Excel's excellent graphical capabilities. The simulation software stores and graphically presents time-stamped data from a run, enabling detailed analysis of different process configurations. Final success of a simulation run is measured by inter-shipment variability (standard deviation and process capability) and in-process ore tonnages. Meaningful results from the simulations require the initial input data contain the same correlations present in the real production environment, between the mineral components, production linkages and across time. The data also have to allow simulation of potential changes to mining method and introduction of new pits into the blend. Mining data from the real operations under study are therefore used, with average grades and variability adjusted to match potential future development proposals. It is also necessary to filter out medium and long-term variations from the production data as this variability is best controlled through the conventional medium to long-term mine planning process, not by the process design being studied. The filtering was carried out using a Fourier transform technique, which is described.

Jan 1, 2009

By Jack L. Henry

The Bureau of Mines conducted seven pioneering experiments in a 12-inch-diameter Kroll reduction reactor to examine the feasibility of coreducing the chlorides of Ti, AI, and V to produce a homogeneous titanium alloy sponge. The coreduction studies proceeded in a normal manner, and the yields of sponge were comparable with those of pure titanium sponge made in the same reactor. Vanadium concentration was very uniform throughout the sponge cake when VC14 in solution in TiCl4 was fed into the molten magnesium. More difficulty was encountered in feeding solid VCl2 and AIC13. Vanadium and aluminum concentration in the sponge was not uniform, and mechanical difficulties were experienced with the small-scale screw feeder. Although the sponge varied in composition from region to region, the ingots prepared from it were uniform in composition.

Jan 1, 1974

By A Horeth, E Duggan, B Versiani, A Gooch

Iron ore screening plant productivity is strongly affected by the performance of the shuttle operation, with the control system robustness and associated strategies having a direct impact on utilisation and throughput rates. A number of aspects intrinsic to the methods and technologies traditionally applied on the motion control of shuttles are often observed to decrease the efficiency of the ore distribution process across multiple screening modules, which ultimately impacts the plant’s production. Those include the number of operational scenarios that are unmanaged by conventional discrete control logics which may intermittently lead to undesired events, such as ‘high level alarms’ and ‘low level interlocks’ in the screening bins. This outcome usually demands excessive manual intervention by Control Room Operators. A Reinforcement Learning (RL) Artificial Intelligence (AI) solution was deployed to control the motion operation of the scalping and products screening shuttles in an iron ore handling plant. The RL algorithm was trained in advance to handle multiple operational scenarios and generate optimised outputs. In nominal operation, the shuttles are moved in a modulating and highly predictive fashion over the whole range of safely reachable bins. When the need occurs, the AI control agent deviates from that modulation behaviour, limiting its travel range or moving to other groups or clusters of available bins by employing ‘bin jumping’ or ‘ore break’ strategies. The RL platform capabilities include the ability to learn in real time to account for and auto-adapt to new operational patterns and process changes whilst applying improved strategies for shuttle dwelling times, target setting and speed control. The deployed Reinforcement Learning AI solution has better managed the existing challenges associated with the shuttle operation and control, and resulted in a more efficient ore delivery process, superior operations stability and increased production rates.

Nov 8, 2021

By Eduardo Reis de Oliveira

O alumínio por suas excelentes características físico químicas é empregado na indústria civil, automotiva, naval e aeroespacial. As características mecânicas dos sistemas solidificados dependem do arranjo microestrutural, mais especificamente do tamanho de grão, espaçamentos celulares ou dendríticos, das heterogeneidades de composição química, do tamanho, forma, distribuição das inclusões e das porosidades. A fusão de metais e, consequentemente, a solidificação, são etapas importantes na obtenção dos metais. Neste estudo iremos investigar a solidificação vertical ascendente em regime transiente do sistema Al-Mg. Está análise investigou experimentalmente o efeito das composições e dos superaquecimentos nas microestruturas solidificadas. Durante a fabricação dos lingotes, foram mapeadas a solidificação de cada liga. As microestruturas obtidas evidenciaram um aspecto essencialmente dendrítico, verificados através da microscopia óptica. É estabelecido no trabalho uma comparação entre os espaçamentos dendríticos primário (EDP ou ?1) e secundário (EDS ou ?2) em relação adição de 1, 3 e 5% de Mg e com patamares de superaquecimento (?TV) variando em 20, 40 e 60ºC.A variação do superaquecimento e da composição química dos lingotes teve influência nos espaçamentos dendríticos, verificados nas medições transversais e longitudinais dos lingotes. Para cada posição analisada foram obtidas uma média dos valores e o respectivo intervalo de dispersão.

Oct 30, 2017

By N. K. Dumakor-Dupey, G. B. Sakyi-Addo, K. J. Bansah

"Artisanal and small-scale mining (ASM) occurs in many countries around the world, and provides a source of livelihood to many impoverished local people in areas where it occurs. This paper reports the role of female participants and reasons why they engage in ASM. Field visits were made to 12 ASM sites located in the Tarkwa Mining District of Ghana to conduct interviews with male diggers and female participants. It was observed that over 100 women between the ages of 18 and 50 participate in ASM for survival. They engage in ASM largely because they have no alternative employable skills and income sources. These female participants depend on ASM to sustain the lives of their dependents. INTRODUCTION Artisanal and small-scale mining (ASM) conventionally involves use of rudimentary tools (such as picks, shovels, chisels and hammers) to exploit precious minerals and metals from the ground. It has been a major source of livelihood to many impoverished local people for more than a century. In many instances, it is the only source of income to indigenous people who have no alternative employable skills. The World Bank estimated that more than 100 million people around the world benefit from ASM which largely occurs in developing countries in Asia, Africa, Oceania, and South and Central America (World Bank, 2013). Cobalt, which is used in lithium-ion batteries to power cellphones, laptop computers, and electric vehicles, is largely produced by artisanal miners in Congo (The Washington Post, 2016). In Sudan, ASM is a significant contributor to the national economy, accounting for about 85% of total gold extracted yearly from 2010 to 2015 (Ibrahim, 2015). Also, according to the Embassy of Sierra Leone in Washington DC, USA, 90% of mineral export in Sierra Leone can be attributed to thriving artisanal diamond mining in the country (Sierra Leone Embassy, 2016). In Ghana, the ASM sector was recognized by government as a multimillion industrial activity, and through a series of initiatives, it was legalized by promulgating the Small Scale Gold Mining Law of 1989 (PNDCL 218). Presently, artisanal mining is widely practiced in two forms: licensed (registered), sometimes referred to as formal ASM, and unregistered (informal or illegal) operations, popularly called “galamsey”, a name believed to have been derived from “gather and sell” by ancient miners who could not communicate in the English language with European/British miners. The ASM sector in Ghana, like other countries, has seen a rise in female participation over the years. A report by the International Labour Organization (ILO) indicated that women account for about 15% of total workforce in ASM in Ghana, and up to 50% in Africa (ILO, 1999). Other researchers have also estimated women participants in ASM to be between 30 and 70% in Africa (Hinton et al., 2003a; Hinton et al. 2003b; Hilson, 2002). Presently, there is no reliable data from Ghanaian authorities on number of females engaged in ASM. However, data obtained from 15 ASM sites suggest that at least 40% of the employees are women. It is expected that a similar trend exists across ASM operations in Ghana."

Jan 1, 2017

By T. A. Rickard

Freeman, the English historian, said that he had learned from Macaulay "never to be afraid of using the same word or name over and over again if by that means anything could be added to clearness or force. Macaulay never goes on, like some writers, talking about `the former' and `the latter', `he', `she', `it', and `they', through !clause after clause, while his reader has to look back to see which of several persons it is that is so darkly referred to". He might have learned also from Macaulay that a preposition makes a' feeble ending for a serious statement. How often do you hear `the former' and `the latter' in conversation? Good conversation is a guide not to be dis¬dained. When you must use `the latter', do not confuse it with `the last'. Cheap labor, cheap fuel, and cheap transport are essential, the latter [last] being particularly important in base-metal mining. The apparatus may be used to determine such gases as hydrogen sulphide, chlorine, oxides of nitrogen and some others, as well as sulphur dioxide. In the case of the latter two, etc. The two last mentioned are "sulphur dioxide" and "some others". He should have stated which two, and he should have avoided that wretched phrase "in the case of ". Pinning may be partly prevented by use of chalk, oil, or turpentine. The latter [last] is best. I "Partly prevented" is a poor phrase. `Prevented! is a word that does not lend itself readily to modification. He means `checked' or `corrected'.

Jan 1, 1931

By T J. Grandfield

Paste fill has been used successfully at Henty Gold Mine for the past five years. It has allowed 100 per cent extraction of the orebody, stabilised poor ground and enabled wide sections and offsets to be mined safely. However, there are a number of inefficiencies in the current paste fill system. These include the low output from the drum filter, the addition of aggregate to the paste to compensate and the trucking of paste from the plant to the portal. These inefficiencies have increased the operating cost of the paste fill system and caused a number of operational challenges such as blockages and increased pipe wear. These challenges have been partly overcome by taking ownership of the paste fill process, improved quality control and better communication. Henty is currently developing two new orebodies, the Mt Julia and the Darwin and has an opportunity to build an efficient paste fill operation. This is likely to be a high density paste system without aggregate, either located above the new orebodies or located at the plant and pumped to the new site.

Jan 1, 2002

By James Aston

A PROPER consideration of this subject is not confined to the technical channels of production and metallurgy. It concerns an industry, and should cover economic aspects which are of material importance in any program of development. The discussion may logically be treated under three subdivisions, as follows: (1) manufacture, (2) characteristics related to quality of material; (3) adaptability and exploitation of product. MANUFACTURE OF WROUGHT IRON The manufacture of wrought iron is the most ancient art of the ferrous metal industry. The eighty years or less of existence of processes identi-fied with our modern "Age of Steel" is a relatively brief interval com-pared with the several thousand years associated with the production of wrought iron by man. From the primitive early methods of production, manufacture for many centuries followed the line of direct reduction. There were developments as experience was gained through the years; but man's needs for a strong, ductile, forgeable product were met by reducing the ore to metallic iron in a single-stage operation. Following the development several centuries ago of what has become our modern blast-furnace operation, manufacture of wrought iron was gradually transformed into a two-stage method of first producing cast iron and then refining this to the desired degree of forgeability; the fore-runner in principle of today's scheme of manufacture of steel. The product retained the essential characteristics of highly refined base metal with iron-silicate slag incorporation, which were associated with the material resulting from direct reduction methods. Cort's invention of the puddling process in 1784 is a landmark in wrought-iron manufacture. It consisted essentially in adapting a coal-fired reverberatory furnace to the refining operation; thus lifting the industry out of the slough of

Jan 1, 1935