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By J E. (Boet) Coetzee

SAFEX International, as the name suggests, is a global organisation, which has the fundamental objective of improving the safety of operations concerned with the manufacture, storage, transport, and use of commercial and military explosives and pyrotechnic products throughout the world. It is a nonprofit making organisation of manufacturers of explosives from all parts of the world, founded in 1954 with the aim of exchanging experiences within the explosives industry. Every third year SAFEX organises a Congress during which members present papers on selected themes and discuss reports of significant incidents that occurred since the previous Congress. Admission is for SAFEX members only, thereby creating a safe environment for discussing problems “within the family”. The XV Congress will celebrate the Association’s 50th anniversary in Geneva where it was founded. An overview of the Congress indicates its structure and covers aspects such as the training event, technical seminars and the themes for the plenary sessions and associated workshops. The paper also highlights the special event for the chief executives of member companies and the review of incidents that occurred in the industry since the last Congress. The Congress concludes with a social programme for delegates and their partners on the last day.

Jan 1, 2005

By I-H. Jung, J. Kim, B. Konar

"The usage of FeNdB permanent magnet, containing Rare earth elements (REEs), is steeply increasing with its demand for wind-turbine and electrical vehicle. The improvement and recycling of the permanent magnet require good understanding of chemistry of all constituent elements. In order to understand the chemical interactions between REEs and Fe, all Fe-RE binary systems have been critically assessed and optimized based on reliable literature data. The Modified Quasichemical Model and Compound energy formalism is employed to model the liquid phase and the solid solutions present in the binary systems respectively. The enthalpy of the liquid and the intermetallic phases showed a systematic trend along the lanthanide series. This helped to mitigate the discrepancies in literature data and also to predict the binary interactions between some less well investigated Fe-RE binary systems. INTRODUCTIONRare Earth elements (REEs) are a group of seventeen elements (including Scandium, Yttrium and the lanthanide series) that exhibit same characteristic chemical and physical properties. These properties make them valuable to the electronic, appliance, green technology, weapon and medical device manufacturing industries. Compounds of REE with other metals (like Co, Fe, Ni etc.) have unique properties of luminescence, thermal and electrical conductivity, magnetism and ability to act as catalysts and polishing compounds (Gschneidner ,2011).They are not only indispensable for some electronic gadgets of today, like computers, music systems, mobile devices, televisions and MRI machines, but also holds a key to more greener technology of the future. They contribute to the development of more efficient and environment friendly version of everyday products such as cars and light bulbs. REE compounds revolutionized the magnet industry by making them smaller and more powerful with increased longevity, and high temperature workability, which are used in motors and generators that power electronics, telecommunications, electric automobiles and turbines(Humphries, 2011)."

Jan 1, 2012

By W. J. Tough

THIS paper offers examples of some of the typical calculations which occur in the ventilation of metal mines. The fi.rst section of the paper discusses the problems associated with natural-draft pressure; the second section presents the more common of the calculations concerned with the operation of mine fans; the third section illustrates the integration of the individual problems covered by the preceding sections into the larger problem of determining the operating characteristics of a fan for a particular mine duty. There is a very definite limit to the extent to which pure arithmetic can be successfully applied to the solution of min<; ventilation problems. As mines advance from the exploration, development, and initial production stage to the rime when underground workings become exceedingly complex, there is a considerable increase in the relative importance o theory and judgment in the solution of ventilation problems. These calculations illustrate the application of mathematics to ventilation, but they also in-elude examples of instances where arithmetic cannot be conveniently applied, and important estimates, based on judgment compounded of experience and a knowledge of the theoretical consideration involved, must be made. The inclusion of such estimates is intended as a guide and a warning to the reader; a guide in assisting him to recognize and estimate his own incalculables; and a warning that the solutions must not be blindly applied to his apparently similar problems. These sample calculations are intended to assist the reader in applying the theory contained in the standard texts on metal-mine ventilation. They have been selected from the ventilation experience of a British Columbia mine.

Jan 1, 1942

By David S. Holmes

An overview of existing biological technologies for the recovery of copper and uranium is presented. Engineering and biological challenges and opportunities in these areas. are discussed. New opportunities for the biooxidation of refractory gold ore are described. Techniques for the development of new strains of microorganisms. for commercial metal recovery applications are discussed with special reference to the genetic manipulation for bacterial strain improvement.

Jan 1, 1991

By Steven E. Paulson

In situ mining is emerging as a potential alternative to conventional surf ace and underground mining techniques. A major factor in determining recoveries by in situ mining is the proportion of ore minerals that can be contacted and solubilized by the leach solutions. To provide basic information on the processes occurring during in situ leaching, particularly at the microscopic scale, the Bureau of Mines has developed a geologic characterization research program. This includes laboratory experiments using leaching apparatus that can accommodate whole core samples. Whole core experiments result in higher leach solution-ore mineral contact ratios than packed column experiments, and also allow for the assessment of permeability changes taking place as the result of mineral dissolution, precipitation, and clay swelling within the flow channels in the rock. A nonreactive, reusable reaction cell has been designed and tested. The leaching apparatus can be used for constant-pressure or constant-flow experiments and allows for the control of flow rate, pressure, and temperature during the experiments, thus permitting studies on a wide variety of ore samples. Details of the experimental apparatus and design are presented, as well as preliminary results from the first series of experiments on an oxide copper ore from the Casa Grande, AZ, area.

Jan 1, 1987

By Hugo L. Johnson, Robert Wallace

THE Midvale plant of the United States Smelting Refining and Mining Company consists of a flotation mill for concentrating sulphide ores of lead and zinc by differential flotation to produce three separate concentrates, one of lead, one of zinc, and one of iron pyrite; and a lead smelter for smelting ores and concentrates to produce base lead bullion, The plant, including its shops, laboratories, office, railroad yards which serve both mill and smelter, and areas reserved for tailing ponds and slag dumps, covers 646 acres on the right bank of the Jordan River at Midvale, Utah. It is twelve miles south of Salt Lake City and sixteen miles east of the West Mountain mining district at Bingham Canyon from which is drawn a large part of its ore supply. Custom ores are treated as well as the product of Company mines.

Jan 1, 1948

By Zhiwei Wang, Chunsheng Qiao

"Aiming at the problems of the existing calculation methods for the support pressures of shallow tunnels in layered jointed rock strata, by using OAT (orthogonal array testing strategy) and DEM (distinct element method), 12 influencing factors including the thickness of the weathered overburden, and the states of the rock joints were considered. Then, the classification of the loosening zone was analysized. On this basis, by using the DEA (data envelopment analysis) theory, quantitative analysis on the influencing factors was conducted. By analyzing the influence of the key factors, a prediction formula of the boundary of the ringent trumpet-shaped loosening zone was established. According to principles of stress transformation, the formula of support pressures of the loosening zone which could considering the key factors were deduced. Finally, a practical case was introduced and studied to verify the proposed method.INTRODUCTIONIn recent years, various urban subway tunnels are increasingly carried out through jointed rock strata in many cities. Rock masses are discontinuous mediums with fissures, fractures, joints, bedding planes, and faults. The frequency of joints, their orientation with respect to the engineering structures, and the roughness of the joint have a significant importance from the stability point of view. However, there is a lack of understanding about the influence of the joints on the stability of tunnels. Therefore, how to measure the degree of the joints’ influence is a problem that needs to be solved.For the calculation of the support pressures, until now, many research results were focused on soil ground (Bierbäumer 1913; Terzaghi, 1943; Peck, 1969; Sabatini et al., 1999). In terms of site tests and model indoor tests, by measuring strut loads and calculating earth pressure based on strut spacing, the results proposed by Peck (1969) and Tschebotarioff (1973) have been widely used in practice for designing excavation support systems under sand (drained) and clay (undrained) soil conditions. Note that, it is unclear whether these findings could be extended to rock strata. For numerical simulations, how to simulate the states of the rock joints is a key problem that needs to be solved."

Jan 1, 2015

By H. P. Wheeler

WHEN Germany invaded Poland in September, 1939, the only operating helium plant in the United States was that near Amarillo. Texas, supplied with helium-bearing natural gas from the near-by Cliffside gas field. Today the Bureau of Mines has five plants capable of producing more than 25 times the prewar helium output of the Amarillo plant. Two of the plants have received Army-Navy "E" flags for their part in the faraway "Battle of the Atlantic," where heliumfilled Navy blimps chased Adolf Hitler&apos;s submarines away from American shores. Meteorologists, watching balloons carried high into the stratosphere by helium, determined weather conditions that influenced the selection of D-day and dates for other military operation. Demand for helium doubled overnight when the Navy decided to expand its lighter-than-air activities; and as the blimp patrol proved effective, the helium demand became ever greater. A tribute to the success of the Bureau of Mines in meeting the demand for helium was paid by the late Secretary of the Navy, Frank Knox, in a letter to the Secretary of the Interior on April 10, 1944. Secretary Knox wrote, in part,

Jan 1, 1945

By D Audeyev

The Cooljarloo North Mine has been shaped not only by operational and processing challenges, but by climatic and economic factors. This paper outlines some of these challenges and discusses how the operating strategy has been altered over time to mitigate the impacts.Since commissioning the wet concentrator in 1999, there have been many typical operational challenges to maximising valuable heavy mineral (VHM) recovery. These include: varying in pit feed grades, different slimes types and volumes, sizing extremes between VHM and trash minerals and decreased equipment reliability handling rocky ore. These issues were successfully mitigated by: in pit extraction strategies, upgrade of the de-sliming circuit, thickener modifications and flocculent changes, installing upgraded and additional spiral capacity, and various Feed Preparation Plant screening initiatives. Combined with the ingenuity, persistence and patience of the operating team, VHM recovery >95 per cent has been achieved.However, typical processing challenges have not been the only hurdles. Reduced rainfall and water availability has necessitated the strategic co-disposal of tailings and slime to increase the speed of water recovery: groundwater abstraction and water storage strategies have also been altered. With an observed reduction in the speed and magnitude of groundwater recharge, overburden backfill scheduling has become a priority mine planning function.Combined with the above challenges, the prevailing foreign exchange rate and mineral product prices have impacted profitability. At the height of the Global Financial Crisis in 2009, major changes to the operating strategy were made to maintain a viable dry mining operation in 2010. Working with the mining contractor the existing scraper and semi-fixed Feed Preparation Plant set up was replaced with a movable in pit dozer trap facility. The end result of changes to the mining method and primary screening was a ten per cent reduction in unit costs. This article will elaborate on some of the above mentioned challenges and successes achieved over the past ten years of operating the Cooljarloo North Mine.

Oct 5, 2011

By Chris Cross

A working group from Anglo American, BHP Billiton, Rio Tinto and Xstrata reviewed supply and demand for graduates from mining education departments in countries where they normally recruit: Australia, Canada, Chile, Western Europe, South Africa and USA. Departments are typically small and increasingly unsustainable, resulting in a steady rate of closure. Supply and demand for graduates in the minerals industry is cyclical, with supply lagging behind demand and trending downwards. Currently, supply is tight and the industry is trying to expand with an ageing workforce. Greater collaboration between universities and within the industry is recommended to address these issues.

May 1, 2006

By H. E. Harris

It has long been recognized that one of the principal ways of combating dust in coal mines is by means of water sprays. However, spray systems, currently in use, clog or plug frequently, thereby reducing the effectiveness of dust control aid, in turn, possibly increasing the health hazard to mining personnel. Moreover, the maintenance and replacement of spray system components, e.g., nozzles and filters, can be expensive in terms of direct costs of labor and material, and the consequent loss of production. Recognizing these problems, the Bureau of Mines sponsored a research project on the "Development of a Non-Clogging Water Spray System"; this project was carried out by Eastern Associated Coal Corp. The overall objective of this project was to develop a non-clogging water spray system suitable for use in underground coal mines. Since most of the dust formed is at or near the working coal face, emphasis was placed on face equipment such as a continuous mining machine. To accomplish this objective, a two-phase project was carried out. The first phase involved determining the causes of spray nozzle and spray system clogging, determining the availability of spray nozzles or systems that could be modified to be non-clogging, and developing a non-clogging water spray system. Phase two was concerned with the fabrication and the laboratory and field testing of a non-clogging system. In each phase, there were both laboratory and field investigations, and the results of these investigations are presented in this report.

Jan 1, 1975

By J. G. Kirby

According to the Bureau of Mines annual survey, there were 318 petroleum refineries in the United States with a total daily crude throughput capacity of 8,632,390 barrels as of January 1, 1956. Compared with the previous year the total number of refineries declined 8 while the crude throughput capacity increased 211,760 barrels daily. Three refinery districts accounted for 90 percent of the crude-oil capacity increase, the California district 34 percent; the Texas Gulf Coast district, 31 percent; and the Indiana-Illinois-Kentucky district, 25 percent. Decreases in capacity during the year were reported for the East Coast, Appalachian #1, and the Arkansas-Louisiana Inland districts. The capacity of the average refinery to process crude oil increased during 1955 from 25.830 barrels daily to 27,145.

Jan 1, 1956

By D. Loy LeRoy

As we are all aware, the impacts of the 1977 Surface Mining Act and the implementing OSM Regulations require application of new, as well as existing, equipment and technologies. Our firm recently completed (June, 1979) a study for the Department of Energy titled "Analysis of the Impact of Public Law 95-87 on Mining Performance." The objective of the study was to analyze the impact of the Act and its regulations on mining performance in order to provide recommendations to alleviate the impacts identified, including identification of research needs. This paper presents some of the highlights of that report: projected cost increases; additional equipment needed for compliance; review of methods currently practiced or those which can be modified; and will focus particulary on equipment and technology applications.

Jan 1, 1980

By P. Nicholls

Patent records show that the idea that the burning of fuels can be improved by mixing or pretreating them with chemicals 6 dates back to the early years of the last century. By 1845, English and French patents included the specific beneficiations of elimination or reduction of smoke, soot, and clinker; reduction of the ashes, presumably meaning the total weight of refuse from the ashpit; elimination of sulphur fumes; increase in the rate of burning; increase in the time a given charge of fuel would last; and, in most patents, a saving of fuel. The earlier patents specified additions up to 80 pounds or more per ton of fuel, but after 1860 the quantity was rarely more than 4 pounds. There is no record of the extent to which these patents were commercialized, but after 1884 many American patents were assigned to companies specializing in treatment of coal, so it is probable that the products were marketed on a considerable scale at least as early as that date. From 1900 on, many companies marketed proprietary products that were sold under the general name of "fuel savers." Since its establishment in 1910, the Bureau of Mines has continually received inquiries about these products and, at the request of other govern-mental departments, has tested some used in accordance with the instructions of the purveyors; the results were all negative and, within the accuracy of measurements, the products had no effect on the burning.

Jan 1, 1937

By Seth Robertson, Daniel Belardo, Travis Coleman

Thermal Integrity Profiling (TIP) is a non-destructive method used to evaluate drilled deep foundation integrity. This integrity testing method is specified more frequently, and is becoming an industry standard in the transportation and private construction sectors. This testing method utilizes heat generated during the concrete/grout curing process to assess deep foundation integrity over the evaluated length. With compilation of the measured temperature versus time and installation records, a model of the Effective Average Radius versus measurement depth is generated. The generated effective shaft model is highly dependent on specific construction details, subjective modeling parameters, and proper interpretation of concrete/soil heat dissipation characteristics. Key components of the TIP analysis include both qualitative and quantitative assessments. Qualitatively, variations or sharp reductions in temperature profiles may indicate potential anomalous regions. Quantitatively, a correlation is established between measured temperatures and estimated Effective Radii for subsequent integrity evaluation. Best practices in processing the TIP measurements are presented, including selecting the optimal time for analysis, normalizing the thermal profile, and proper interpretation of potential anomalous regions. Recommendations for implementing mitigation efforts and interpretation of the TIP results are presented.

Sep 8, 2021

By P. A. Bloom

Bureau of Mines research was conducted to develop effective separation methods that might be used in exploiting substantial tonnages of complex barite-fluorspar ores in Arizona. The exploitable reserves now may be increased as recent batch and continuous flotation tests demonstrated that a complex barite?-fluorspar ore from the Red Chief deposit, Yuma County, Ariz., could be selectively treated to concurrently produce (1) fluorspar and (2) a barite byproduct of marketable grade. The sample contained 24.8 percent CaF2 and 24.3 percent BaS04. Processing comprised production of a fluorspar product containing 97 percent CaF2 with an 82 percent recovery, using a sodium fluoride-lignin sulfonate-fatty acid reagent combination. Concurrent retreatment of the fluorspar tailing, using sodium cetyl sulfate as a collector, yielded a barite product of 94 percent BaS04 grade with a 71-percent recovery. The products met specifications for acid-grade fluorspar and drilling mud-type barite.

Jan 1, 1963

By Manuel Gomez

This report presents experimental work conducted on a number of coals found within the boundaries of the Missouri River Basin, which were, to an extent, a selection of coals typical of that region. In the min, the laboratory work falls into three general classifications: (1) Laboratory distillation assay of coal to establish yields on carbonization; (2) chemical analyses of the coal samples before drying or carbonization; and (3) chemical analyses of the products of carbonization. It will be seen in the following discussion that these data derived from the small-scale laboratory apparatus are useful in predicting yields from pilot plants or industrial units. Coal is produced in about 48 general areas or mining fields in the Western States, of which approximately 18 fall within the limits of the Missouri Basin.3/ Beginning with the Northern Colorado field, through the Central and Western Wyoming fields, the coal is principally bituminous and subbituminous rank. The western Montana coals are also of these ranks. Progressing northeast from central Wyoming the coal decreases in rank, as shown by the subbituminous C coals of the Gillette field in northern Wyoming and the lignites of eastern Montana and North Dakota.

Jan 1, 1953

By Hoffmann CF

Thermal conditions at depths of several k.i&apos;-.r.,etres in hydrothermal systems are a major (actor controlling gold transport into the epithermal environment. Understanding of the coupling of thermal, metal and ligand (HZZ S) sources in the root zones of hydrothermal systems therefore becomes important for the application of tectonic and igneous petrochem- ical studies to regional scale precious metal exploration. The evaluation of favourable conditions in this source zone and application to explor- ation rests on a detailed knowledge of the gases, H2S, CO2 hydrocarbons and other trace components preserved in fluid inclusions. Recent developments in analytical techniques now permit examination of these components and the recognition of complex hydrocarbons in rluid inclusions from epithermal and other lydrothermal systems appears promising for ieoosit-source correlation.

Jan 1, 1987

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. This paper is a continuation of a series made in cooperation with the Coordinating Fuel Research-(CFR) Committee of the Coordinating Research Council (CRC), Inc. The first of this series of reports presented data on motor gasolines sold during the winter of 1935-36, and succeeding reports described motor gasolines sold during the summers and winters to and including the summer of 1941. 2/ No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43. the semiannual reports were resumed.

Jan 1, 1950

By J. W. Downey, A. E. Dwight, M. H. Mueller, H. Knott, R. A. Conner

Sixty new ternary equiatomic compounds are reported with a hexagonal crystal structure that is isostructural with or very similar to Fe2P, D3h-P62m. HoNiAl is a typical example, with a, = 6.9893 ± 0.0003Å, C, = 3.8204 ± 0.003Å, and c/a = 0.54 7. Three holmium atoms occupy (g): x,0,1/2 three aluminum atoms occupy (f): x,0,0; one nickel atom occupies (b): 0,0,1/2; and two nickel atoms occupy (c): 4, + , 0. The nonequivalent 1(b) and 2(c) sites give rise to two sets of unequal interatornic distances (i.e., Ho-Ni and Al-NL in the case above), which account for the prevalence of Fe2P-type tertmry compounds and the scarcity of binary examples. Unit-cell constants are presented for the sixty compounds and density measurements on the compounds HoNiAl and UFeGa confirm that three formula weights are present per unit cell. Neutron and X-ray powder diffraction intensity measurements were made on CeNiAl and HoNiAl, respectively. The atomic posiLiotml parameters in CeNiAl were determined from neutron data to be x = 0.580 5 0.001 for cerium and 0.219 5 0.001 for aluminum. An investigation of the quasibinary section between the binary compounds CeNi2 and CeA12 revealed a new ternary compound CeNiAl. The compound has a hexagonal structure and is isostructural with the prototype compound Fe2P. Additional examples discovered or confirmed in this investigation provide a total of sixty ternary compounds that are isostructural with or closely related to Fe2P. Previous investigators1&apos;2 reported the unit-cell constants for the hexagonal compounds UFeA1, UCoAl, UIrA1, ZrNiAl, ZrNiGa, HfNiAl, and HfNiGa and the present investigation has confirmed that the compounds are isostructural with Fe2P. Independently, Steeb and petzow3 reported the same structure type for UCoAl, UIrA1, and UNiA1. However, the present results suggest a different atomic site occupancy for the component atoms in the three compounds. A detailed investigation of the relative positions of the three kinds of atoms in the compounds CeNiAl and HoNiAl will be discussed. EXPERIMENTAL PROCEDURE The equiatomic alloys were prepared from elements of 99.9+ pct purity by arc melting under a helium-argon atmosphere. After homogenization at temperatures from 700" to 900&apos; C, a metallographic examination was performed by conventional methods, and density measurements were carried out by the immersion method in CCl4. A powder sample was prepared for diffraction studies by crushing a portion of the annealed button. X-ray diffraction patterns were obtained with a Debye-Scherrer camera, in which the annealed powder was glued to a quartz filament, and indexed with the aid of a Bunn chart. Unit-cell constants were calculated from the computer program of Mueller, Heaton, and Miller4 and d spacings were obtained by the program of Mueller, Meyer, and Simonsen.5 The intensity values were calculated from the relation I, ~ (m)(L.P.)F2 by a computer program written by Busing, Martin, and Levy.6 The absorption and temperature correction factors were neglected. An X-ray study of HoNiAl was carried out to take advantage of: large differences in atomic scattering factors for holmium and aluminum, X-ray patters free of background darkening, negligible oxidation at room temperature, and negligible weight loss in the preparation of this alloy. The neutron diffraction studies were made on a powder sample of CeNiAl contained in a -in. diam V tube and a pattern was obtained with neutrons of wavelength The neutron scattering factors employed (x 10-12 cm). In contrast to the scattering amplitude for X-rays, cesium does not have the largest cross section, however, there is a sufficient difference in the neutron scattering amplitudes to distinguish between the atomic species. The neutron transmission was high, 86 pct; therefore, absorption corrections were not necessary for the cylindrical sample. Most reflections could not be observed individually, because of the relatively large unit cell (a = 6.9756 and c = 4.0206Å) and relatively short neutron wavelength; therefore, the intensity of grouped reflections was considered. The Kennicott modification7 of the Busing-Martin-Levy program6 was employed to determine the identity of the atoms at the various lattice sites and the positional parameters. RESULTS A structure for the prototype compound Fe2P was first reported by Hendricks and Kosting;8 however, the structure was in error. The correct structure, as reported by Rundqvist and Jellinek,9 is as follows. The unit-cell constants and volumes per formula weight (V/M) are given in Table I for the sixty compounds examined in this investigation and classified as Fe2P-type compounds. The structure type was determined initially from a comparison of the unit-cell constants of HoNiAl with other known examples of this structure type1&apos; and from the density of HoNiAl, given in Table 11. The density indicated that three formula weights comprised a unit cell, as in the prototype compound Fe2P. The assignment of the three species to lattice sites was made initially on the basis of atomic size. The large holmium atoms were assigned to the 3(g) sites that have a relatively large interatomic distance to nearest neighbor positions, the small nickel

Jan 1, 1969