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By K. L. Lamb

At the Sierrita mine, 40 km (25 miles) south of Tucson, Arizona, Duval Corporation is rapidly gaining operating experience with its new Portable Crushing and Conveying System, (PCCS). As of November 23, 1983, over 4.5 million tons (5.0 million st) of ore have passed through the system. Mining cost per ton for the months of July, August and September was 83% below the average for the first five months of 1983. Although all the cost reductions experienced cannot be attributed to the Portable Crusher, it was a major contributing factor. The Sierrita ore deposit has several natural topographic and geologic conditions which are not favorable to mining. It is not a sidehill deposit and therefore no low-level exit points exist to facilitate truck haulage. The ore is very hard. Quartz diorite, hardest of the three major rock types, averages 172-207 MPa (25-30 000 psi) unconfined compressive strength and may run as high as 345 MPa (50 000 psi). Blasting in this rock produces oversize material which runs approximately 20% 51 centimeters (20 inches). The ore is low grade, averaging slightly better than .30% contained copper and .035% contained molybdenum, with small amounts of silver. These conditions, plus high design production tonnages, make the Portable Crushing and Conveying System (PCCS) practical for Sierrita. Without crushing and conveying, truck haulage would be prohibitively expensive. A typical, October, 1983, ore haul from the bottom of the pit would involve a vertical lift of 260 meters (850 ft) and a horizontal distance of 3 860 meters (12 200 ft) were not in-pit crushing and conveying available. The corresponding cycle time would be nearly 32 minutes.

Jan 1, 1984

By Jerry C. Tien

The rare earth elements (REEs) are a group of 17 chemical (metallic) elements. REEs are used widely in high-technology, clean-energy products as well as weapon systems. China's dominant position as a producer of over 95% of the world REEs output and the world's increasing reliance on REE products have highlighted concerns about the future availability of rare earths in recent years. This paper briefly reviews the REEs world reserves, production, consumption, the impact of our heavy reliance on REEs products and China's changing policies on REE export on world supply chain.

Jan 1, 2013

By W. R. Peters

An experimental hole-to-hole seismic probe system has been developed for use in coal measure geology as a means of determining the structural conditions of coal seams. The source probe produces a 500-joule electric arc discharge whose seismic wavelet has a spectrum in the 200 to 2,000 Hz frequency range. Low compliance hydrophones contained in the source probe as well as in a separate seismic detector probe are matched to the frequency range of the source. Both probes are constructed with 5-72 cm diameter housings. The transducers in the probes are equipped with fluid-inflatable boots to permit operation in either wet or dry boreholes. Preliminary tests in vertical boreholes drilled 213 m apart in sedimentary rock formations show reliable operation and useful seismic propagation measurements along horizontal and oblique paths up to 232 m in length. Because the seismic wave- let has an accurately repeatable waveshape, multiple shots and signal averaging techniques can be used to enhance the signal-to-noise ratio and extend the transmission distances.

Jan 1, 1985

By M. W. Buche, E. Tarshizi, R. Chappidi, B. Inti

"Coal mining is an age-old method of power production in the world. It is also widely known for the associated risks during mining. Although the number of mishaps has dropped dramatically over the years, the number of fatal accidents is still a concern, and any aid in reducing these figures would be important to industry workers. Therefore, data from accident reports during the past seven years were collected and analyzed. Qualitative data from reports and articles provide a deeper understanding of the incidents, thus affording the possibility of identifying patterns and relationships between the accidents. For this study, a total of 119 fatality accidents occurring in U.S. coal mining operations were analyzed using advanced text mining techniques. The fatality data were obtained from U.S. Mine Safety and Health Admininstration fatalgram reports. This analysis is primarily exploratory in nature and uses term frequencyinverse document frequency (TF-IDF) methodologies along with correlation network plots. An interesting word relation pattern was obtained that identified “positioning” as the common cause of 12.6 percent of accidents, and found that 29.4 percent of accidents can be categorized as vehicle-related. IntroductionIn the mining industry, accidents are situations that employees and employers wish to avoid. They are devastating experiences to the victims and their coworkers alike. Even worse, accidents that result in fatalities create trauma and undesirable repercussions. Several measures have been taken throughout the industry to prevent such mishaps, and the U.S. Mine Safety and Health Administration (MSHA) provides continuous monitoring for miners’ safety by guiding organizations through best practices in every job role. As a result, according to MSHA, there has been a steady decline in the average number of deaths due to accidents over time. Nonetheless, any opportunity to avert one more such casualty is of paramount importance, and that is the goal of our analysis. Our objective is to identify opportunities resulting from previously unexplored directions in order to provide additional insights into potential safety recommendations. Until now, most of the studies in this area had been conducted using structured and tabulated data with a constant number of categorical and numerical variables. Unstructured text data mining is an emerging area that is still insufficiently researched and has a feasible scope for important results, as a vast majority of human communication and cognizance is comprised of words. The aim of undertaking this project by capitalizing on unstructured data is to analyze the text reports to discover potential relationships that explain the causes of accidents in new light in order to mitigate the occurrence of fatalities. The analysis in this project is based on textual data obtained from the MSHA website (2017). Individual accident reports are organized according to the date and year of the fatality. Each report includes details with images of the incident. For convenience, a simplified summary of the report is also available. Data collection consisted of gathering formal documentation of fatal accidents in the coal mining industry during the past seven years. These reports were extracted from the website in text format."

Jan 4, 2018

By Ernst P. Hall

The Irwin Basin. (Fig. 1)* is a synclinal or shoe-horn *Figure numbers throughout refer to color slides not included with the preprint shaped basin in the Pittsburgh Coal Seam, It is approximately 10 miles wide and 22 miles long at its maximum points. The surface of the land above the basin is hilly, rolling farmland,, typical of this area of Pennsylvania, and it is criss-crossed with streams and highways and liberally dotted with farm houses and communities. In-general the coal is pitched from north to south with a total drop of 610 feet'. The coal seam cross-section from east to west is bowl-shaped and rises as much as 375 feet from the low point of the bowl to-the-outcrop. Cross-sections showing coal elevations are shown on Figs, 4 and 50 Ground cover above the coal will vary from 0 to 550 feet, averaging about 350 feet throughout the area. This area is richly endowed with a history of coal mining. The first car of coal shipped cast of the Allegheny Mountains was mined in the Westmoreland Coal Company's Shady Grove (later North Side) Colliery in Irwin, Pa., early in 1853, This mine was opened in 1852 by Coleman, Hillman & Company. The coal was hauled from the mine to the freight station by horse-drawn wagon and. loaded into a then "standard" box car of 18,000-pound capacity. Coal mining in this region flourished and grew as steel production in nearby Pittsburgh demanded more and more of the high quality, metallurgical-grade coal of the region.

Jan 1, 1959

By K. Lapakko

Kinetic tests results are influenced by methodological variables, including test duration and mine waste particle size. Some samples tested produced neutral drainage in kinetic tests for more than two years prior to drainage acidification. The potential for long "lag times" can be assessed based on the mine waste mineralogy. The lag time duration can be estimated using this mineralogy in conjunction with dissolution rates observed in the kinetic tests. The influence of particle size on the drainage quality is dependent on the variation of the availability of acid-producing and acid-neutralizing minerals with particle size.

Jan 1, 1998

By Leena Suopajärvi, Karin Käär, Marcin Szumny, Jari Joutsenvaara, Md Ariful Islam, Helmut Mischo, Georg Meissner, Ossi Kotavaara, Catalina Vrabie

This study outlines implemented tactics and results for community empowerment through participation in questionnaire surveys, educational programs, and discussion on sustainable sourcing from new critical raw materials (CRMs) projects. Utilising questionnaire surveys, including the Public Participation Geographic Information System (PPGIS), the research gathered public opinions from Estonia, Germany, Poland, and Zambia, receiving 1,068 responses. These responses addressed various social, economic, and environmental issues related to CRM projects. Feedback from educational courses with participants from over 25 nations and public events provided additional insights. The collected data and feedback offer crucial input for advancing sustainable and responsible CRM sourcing strategies in these regions.

Feb 1, 2025

By James A. Finch, Xiang Zhou, Yue Hua Tan

Methods to determine frother functions, control of bubble size and froth properties, are now widely used. Some collectors also exhibit frother functions which are less understood. Using a water-air system in a mini-mechanical flotation cell setup, this paper determines bubble size and water overflow rate for three amine collectors: one primary amine (dodecylamine, DDA) and two commercial ether amines (Flotigam® EDA and Flotigam® 2835-2L) and their combination with two common frothers, MIBC (methyl isobutyl carbinol) and PPG 425 (polypropylene glycol, molecule weight 425). Compared to the frothers, the amines were less effective in reducing bubble size, giving larger minimum size and the two commercial amines showed evidence of coalescence at low concentration. In blends, at fixed frother dosage, frother eliminated the coalescence but as amine concentration increased the amines dominated bubble size. Water overflow was a strong function of reagent type. For fixed 1-cm froth depth, PPG 425, Flotigam® 2835-2L and to a lesser extent DDA produced overflow while MIBC and Flotigam® EDA did not. In blends with frother overflow increased except with Flotigam® EDA. Mechanisms are briefly explored. The principal benefit of blending identified is the elimination of coalescence if residual concentration of the two commercial amines is below ca. 10 ppm.

By E.C. Jong

Resumen ¦ Un sistema de comunicaciones “a través del suelo” (TTE) comercial y disponible fue evaluado en una mina de carbón subterránea en la zona Este del Estado de Kentucky. Este estudio de campo fue realizado como parte de una evaluación multisitio mayor de sistemas TTE disponibles. La mina detallada en este estudio se encontraba paralizada al momento de la evaluación, lo que proporcionó la representación más cercana a la realidad del medio ambiente en una mina luego de una operación de cierre. Para este estudio se probaron las comunicaciones superficie a subterráneo y subterráneo a superficie. El despliegue estándar del sistema TTE usando los procedimientos recomendados por el fabricante logró obtener comunicaciones claras y nítidas entre el socavón y la superficie. Otras disposiciones de las unidades arrojaron resultados mixtos. Existen planes para examinar más los fenómenos observados en esta mina.

Apr 1, 2016

By Alper Kirmaci, Taghi Sherizadeh, Dogukan Guner, Samuel Nowak, Khaled Mohamed, Morgan Sears

Coal ribs present a major safety hazard in underground mines, and there is currently no unified approach for their design in the United States. To tackle this issue, this study investigated the stability of underground coal pillar ribs under development load. Utilizing over a thousand 3DEC models, a framework for calculating coal pillar rib rating (CPRR) was developed. A detailed step-by-step method was outlined for computing the CPRR based on a 3DEC analysis, which was then validated with various 3DEC models, demonstrating a strong correlation between the two models. The results demonstrated that the rib factor of safety (RibFOS) under development load is directly proportional to CPRR, coal mine roof rating (CMRR), and floor strength, and inversely proportional to the overburden depth and rib height. Moreover, a regression equation was formulated to predict the RibFOS based on the aforementioned parameters. Furthermore, empirical relationships were developed between the RibFOS and the applied primary rib support density (PRSD) in U.S. coal mines. To ease the calculations, a stand-alone application, Design of Rib Support (DORS), was developed. This application can be used to assess rib stability and easily calculate CPRR, RibFOS, and PRSD.

Jul 1, 2023

By R. R. Beebe

Marcona Corporation produces about 3.5 million long tons of iron ore pellets annually on its two travelling grate pelletizing machines at San Nicolas, Peru. During 1969, these pellets will be shipped to customers in four marketing areas--Japan, the United States, Europe, and South America. All of these sales are on the open market, and product quality is a major concern. Typical chemical, structural, and quality test results for Marcona pellets are given in Table 1. [ ]

Jan 1, 1969

By Brian W. Mackenzie

The mine development decision is made on completion of exploration to determine whether or not a mineral deposit should be developed to production and, if so, how. This involves the selection of an optimum mine development alternative from a number of technically feasible alternatives and the comparison of this optimum with those of other available investment opportunities. If the optimum is sufficiently attractive, the deposit is developed to production. The selection process is carried out within a framework of corporate objectives and resources. The mine development decision is based on the balancing of two parameters - - rate of production as reflected in plant capacity and cut-off grade. On the basis of available information and experience, detailed revenue and cost 'estimates are made for each feasible combination of plant capacity and cut-off grade. What economic evaluation techniques should be applied to these estimates to reduce each alternative to economic indicators that will enable meaningful comparisons and an informed investment decision? This is the essence of the paper. The determination of optimum plant capacity and cut-off grade has been the subject of intensive research efforts by economists and mining engineers (1-7). Their studies are based on marginal analysis and assume that, at the time of decision, certainty conditions prevail with respect to ore reserves, mining costs and mineral markets. The optimum mine development alternative is defined as that which maximizes profitability.

Jan 1, 1969

Caterpillar and Fortescue Metals Group have moved forward with the delivery, installation and support of a complete Cat MineStar System at Fortescue?s Solomon iron ore mine in the Pilbara region of Western Australia. The complete technology suite was implemented for the first phase of Solomon, the 20 Mt/a (22 million stpy) Firetail manned mine, in October 2012. As part of an autonomous mining solution for phase two, the 40-Mt/a (44-million stpy) Kings Mine, eight Command for hauling Cat 793F CMD trucks were commissioned and commenced operations in the second quarter of 2013. The mine plan calls for a progressive ramp up to 45 autonomous trucks during the next several years. In addition, other Cat MineStar System capability sets, Fleet, Terrain, Detect and Health, are being used across the mobile equipment fleet, including support equipment and light vehicles. Working closely with Fortescue and its mining contractor, Leighton Contractors, Caterpillar and the Cat dealer in Western Australia, WesTrac, are providing a full solution for managing, operating and supporting Cat MineStar System and Command for hauling. The greenfield Solomon Mine has brought together the skilled team from Caterpillar, Fortescue, Leighton Contractors and WesTrac to deliver an efficient, cost effective autonomous mining solution.

Nov 1, 2013

By Lee A. Goetz

Cost control is a lot like motherhood - everyone proclaims its need and its worthiness, but is it really appreciated and used to successfully complete a project on time and within budget? Good Cost Control is a yardstick - requiring fixed definition but this does not mean rigidity for the project. It provides the means for telling: 1. Where you are going 2. When you will complete and 3. What it will finally cost. Cost Control does not fix the price of dreams nor the cost of projects loosely defined. It does not control costs in itself but provides the tools whereby engineering decisions can be made which will ultimately affect the project cost It does not even guarantee that a project will be completed within the original funds - but only, if this reflects management desires.

Jan 1, 1970

By Arthur A. Brant

Your chairman has asked me to deal with questions of education relative to our present and projected trends in the field of mineral expiration. First comes our definition of education--and education is not the merely formal acquiring of academic knowledge, but the understanding, using and projection of knowledge into our channels of life and thought activity. This past year makes us realize the extent to which price and economic cut-off may stimulate or curtail exploration,, But exploration does not consist solely in the discovery of sources of material. There is just as inspiring and imaginative a territory in the develop¬ment of uses and application--and no one in our base metal industry but would hope that our educational processes would fertilize those springs of inspiration that lie dormant in us all, toward the- imaginative conception of new uses--lead roofing cloths or felts, non-tarnishable copper utensils, further zinc solid state application. Thus an educational pattern should seek to develop imagination and thinking beyond--the possibility of that small but oh so difficult step just ahead of the existing,

Jan 1, 1959

By Richard C. Sale

INTRODUCTION The topic of the paper is to discuss the use of micro computers in the construction industry. I will first discuss the present situation of the PCs in our industry followed by a discussion how Guy. F. Atkinson has integrated the PCs into it's organization. I will close with some general comments that any organization should review in order to enhance the use of their PCs both at the job sites and home office locations. PRESENT SITUATION OF THE PCs IN OUR INDUSTRY Today, the possible number of combinations that can be obtained when bringing together the available models of PCs, with their peripherals and software, is astronomical. With this array of equipment that can be bought, plus the new and possibly better equipment that is being put on the market almost daily, it is indeed a very difficult task for an organization to know how to invest its money in computer equipment. At the job sites, the work is fast paced with little time available to fully learn what the PCs can do to help with the required paperwork. I am still waiting for the day when someone has to tell the superintendent at the job site that he cannot start pouring concrete or shoot the next round because no one can get the computer to work.

Jan 1, 1987

By J. L. Furtney, C. Fairhurst

"Although global mineral resources are considered to be adequate to meet the needs of a rapidly growing world population, the United States is becoming increasingly dependent on imports. This could have implications for both the economy and national security. The US is a country with a strong tradition of leadership in science and technology. Impressive advances in autonomous underground mining systems reduce the adverse effects of heat and humidity in deep mines and focus renewed attention on ground control. Developments in computing power open opportunities to develop improved understanding of the important role of discontinuities (faults and fracture systems) and more effective design of deep excavations. Establishment of mining R&D Centers at leading US research universities, jointly funded by industry and US federal agencies is recommended as an effective step for the nation to remain an influential partner in world mining. INTRODUCTION. “None of the arts is older than agriculture, but that of metals is no less ancient.. . for no mortal man ever tilled a field without implements. If we remove metals from the service of man, all methods of protecting and sustaining health and more carefully preserving the course of life are done away with.” Agricola (1558)i Homo sapiens, generally acknowledged as the species from which modern Man has evolved, is considered to have originated in Swaziland some 100,000-200,000 years ago. Evidence of use of minerals in that region has been dated to earlier than 40,000 BC.ii Today, a large fraction of the elements of the Periodic Table are derived from minerals, and finding new applications in development of innovative technologies. Agricola’s comments are as applicable today as ever.iii Metals such as copper, tin, lead, iron and aluminum were mined and smelted several thousands of years BC. It was not until the Industrial Revolution, started in the latter half of the 17th Century in Northern England, where coal was available as an energy source, and iron as the basis for fabricating machinery, that dramatic change to society began to occur. Human toil was replaced by far more powerful machines. Rural communities migrated to work in factories in urban areas. Rapid transportation over long distances became possible, leading eventually to the world of today. The change spread to other parts of the world, bringing wealth and power. Although now well established in some regions, the Revolution has still to arrive in many other parts of the world. This can be seen in Figure 1, which shows the relative wealth, or ‘Standard of Living’ as measured by the GDP/capita, of regions around the world. Regions such as North America, Europe, and Australasia iv are seen to have the highest standard. Thanks to today’s global communications systems, regions with relatively low GDP/capita are well aware of ‘how others live’ – and eager to emulate them."

Jan 1, 2018

By Russell Frith

The entire subject area of micro-seismic events due to stored strain energy, as distinct from gas-driven coal outbursts, can be readily sub-divided into firstly events with their energy source from within the coal seam (termed “bursts”) and secondly, event with their energy source outside of the coal seam in either the overburden and/or floor strata. The reason for sub-dividing micro-seismic events in this manner is that if the causation mechanisms and associated geotechnical conditions are materially different, then effective pre-mining predictions and subsequent operational controls may also differ. Attempting to explain a multitude of micro-seismic event types without consideration of varying source mechanisms will inevitably lead to inadequate causal explanations and effective controls.

By John B. Wright

This paper describes laboratory techniques and subsequent results of Bureau of Mines research to produce chlorination-grade feedstock from an abundant, low-grade, domestic, rock ilmenite ore. The research is part of the Bureau-effort to devise technology that may help decrease U.S. dependence on imported raw materials. A rock ilmenite containing about 46 wt pct Ti02 was smelted in an electric arc furnace with coke, woodchips, and Na2C03 to separate most of the iron as pig iron and to form a low-iron, titanium-enriched slag. The slag was ground, pelletized, oxidized, and then sulfated with mixtures of SO2 and air in a continuous 4.5- to 9.1- kg/h apparatus at 1023 to 1223 K. The sulfated slag, containing 60 to 65 pct TiO2, was reground and leached in water at ambient temperature to decrease the combined levels of the troublesome Ca, Mg, and Mn impurities from 7.0 to 1.7 wt pct. At levels of more than 3 wt pct, these impurities contribute to operating and disposal problems, The final product was upgraded to about 84 wt pct TiO2. This material potentially is suitable for chlorination in a fluidized-bed reactor. The most favorable results were achieved with leached slag sulfated at a feedrate of 4.5 kg/h and at temperatures of 1073 to 1123 K.

Jan 1, 1984

Introduction The US mineral industry in 1983 participated in the recovery from the recent recession. Compared with 1982, the value of raw nonfuel mineral output rose 8% to $21.2 billion. The $218 billion worth of goods processed from this crude mineral output represented a 9% increase over 1982. Even in real terms, these figures reflect growth. Demand for nonfuel mineral materials, of course, depends on the overall state of the economy, which steadily improved each quarter in 1983. Of particular importance to the mineral industry were surges in key mineral-consuming sectors such as construction and automobile manufacturing. New housing starts rose one-third, to 1.7 million units, while automakers turned out about 35% more cars (6.8 million) and 25% more trucks (2.4 million) than in 1982. These are significant increases, even considering recent trends toward smaller, lighter vehicles, and multiple-unit housing. A comeback for the mineral industry, however, is bound to proceed unevenly, particularly at the beginning. Traditionally, the industry lags behind the rest of the economy during a recovery, and some mineral products respond to overall economic improvement more quickly than others. This pattern has been repeated many times and the industry is used to it. Mineral executives know it is best to be patient and cautious during the first stages of an economic upturn. Many experts say that it may take extraordinary toughness, patience, and caution this time around. Steel Improves Raw steel production - a major indicator of both material use and mineral production - rose 14% to 77 Mt (85 million st), stimulating a 7% rise in domestic iron ore production to 39 Mt (38 million It). Still, the iron ore industry operated at less than half capacity, with most major mines remaining closed for part of the year. Iron ore imports dropped 24% to 10 Mt (11 million st), so demand was partly met by withdrawals from stocks. Despite the increase in steel production for 1983, output remained far below levels of just a few years ago. For example, 1983 production was still 29% less than in 1981. Raw steelmaking capacity actually declined about 10% during the year to 122 Mt (135 million st). The industry continued to cite steel imports, especially those from developing nations, as a major cause of domestic capacity loss. As long as steel production remains weak, steelmaking metals suffer. Domestic producers of bulk ferroalloys of chromium, manganese, and silicon operated at about one-third capacity in 1983, with six of the 19 companies involved being closed all year. The US mined no manganese or chromium, and very little nickel, although the country's only nickel mine did resume production in November. Molybdenum production, at 13.6 t (15 st), was only about one-third as much as in 1982. The major molybdenum mines, Climax and Henderson in Colorado, remained closed all year. To meet demand, molybdenum stocks were halved to 19 t (21 st). Mine shipments of tungsten, another mineral tied to steel production, dropped 30% to 1.1 kt (1,200 st) of contained metal. One of the most positive responses to the general economic recovery came from the aluminum smelting industry. By the end of the year, it was operating at about 79% capacity, compared to 59% in January. Nevertheless, the 3.3 Mt (3.64 million st) of primary aluminum produced represented only a slight increase over 1982. Total bauxite imports were about 27% below 1982 levels. Production of magnesium metal rose 11% to 100 kt (110,000 st). But titanium was more typical of other

Jan 5, 1984