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By Tedd B. Bodimer

Why complicate an already complex machine such as a continuous miner by adding roof drills? Immediate permanent roof support is an immediate thought of the mining engineer just as elimination of frequent time-consuming places changes is a thought of the methods engineer. The realization of those two objectives has the potential for improved safety with increased production is the thought of the general manager. Miner-Bolters Used a Generation Ago These are not new thoughts as the 1CM continous miner equipped with two integral roof drills was introduced twenty-five years ago. Approximately two hundred of these machines were sold in the next five years for use in medium and high seam operations. The 1CM miner chassis that remained stationary in the center of an entry or room while the ripper bar was swung and sumped hydraulically provided an ideal platform for mounting two roof drills that could be operated during the continuous miner's production cycle. Two roof bolts could normally be installed in less time than required for the mining cycle. A typical roof drill unit is shown in Figure I.

Jan 1, 1981

By G. Venkateswara Rao

The multi-gravity separator (MGS) is a novel piece of equipment for the separation of fine and ultra-fine minerals. However, the published literature does not demonstrate its use in the separation of Iron ore fines. Therefore, an attempt was made to study the effects of different process variables on the performance of an MGS for the beneficiation of Iron ore fines. The results obtained from this study revealed that among the parameters studied, drum rotation, amount of wash water and angle of inclination play dominating roles in controlling the yield and grade of the Iron ore. The majority of the newly developed Multi gravity concentrators have tremendous potentials for various applications. Therefore, the performance evaluation of these concentrators treating various minerals, coals, heavy metal recovery from tailing dams, etc., have become an active research topic. Several attempts have also been made to develop appropriate mathematical models of individual concentrators. Despite all these efforts, these concentrators have yet to find the widespread applications they deserve. The ?as received? sample assayed 40.80% Fe, 40.90% SiO2,0.24% Al2O3and 0.20 % LOI and all other trace elements within the specified range. The current paper deals with the Mineralogical studies, characterization and process amenability studies of Sub grade Iron ore from Deposit No. 5, Bacheli complex of Bailadila using Multi Gravity Separator (MGS).

Sep 1, 2012

By A. Lam

The use of a liquid fed direct methanol fuel cell (DMFC) as a power source for micro and small portable applications is attractive due to its system simplicity, low temperature, etc. The aqueous methanol is directly oxidized and does not require additional fuel processing steps as in reformate based PEM fuel cells. In addition, the use of a liquid fuel is advantageous with respect to humidification, stack cooling and system energy density. The DMFC however, has technological issues that must be addressed before it can be widely adopted, particularly in larger applications such as small utility and transportation. At present, the crossover of methanol from the anode to the cathode is a major limitation on DMFC performance and fuel utilization efficiency. In this paper we discuss the influence of fuel modification on the control of crossover. This involves the use of different fuel additives and concentrations to minimize crossover. This appears to be the first reported case of the use of fuel modification (additives) to reduce methanol crossover. The rate of methanol permeation under passive conditions is discussed with respect to the different conditions.

Jan 1, 2005

By P. G. Lazenby

This paper describes the latest instrumentation improvements in the INPUT Airborne E.M. System, particularly the new electronic signal-processing techniques. Several anomaly examples illustrating these techniques are shown.

Jan 1, 1973

By Peng Lv, Shiqian Liu, Bin Xu, Qian Li, Yongbin Yang, Tao Jiang

The treatment process of a low-grade refractory gold ore containing sulfide minerals and carbonaceous matters was studied in this work. The gold extraction of this ore by all-sliming cyanidation was only 11.75%. Hence, a pretreatment was necessary. In this paper, a flotation-preoxidation-cyanide leaching process was developed. The concentrate from the flotation procedure was processed using different preoxidation methods. A concentrate containing 34.08g/t of gold with the gold recovery ratio of 81.20% was obtained by flotation. After roasting, microwave heating or alkaline pressure oxidation, the gold cyanidation ratio reached 82.37%, 81.26% and 71.09% respectively. Roasting was an effective, reliable and mature technique to oxidize sulfide minerals and carbonaceous matters. Roasting and microwave heating both produced dangerous environmental pollutants while alkaline pressure oxidation was eco-friendly.

Jan 1, 2015

Solvent extraction-electro- winning appears to be one of the most important processes for the future in the North American copper industry and for this reason both the SX and EW steps are furtive areas for development. This paper has the objective of reviewing the present state of the electrowinning technology. It discusses some recent equipment developments and concludes by discussing the direction the technology will likely go fn the next decade.

Jan 1, 1985

By Ari I. Kogut

Impurity minerals in fluorspar ores and concentrates from a deposit in Southern Africa have been studied by reflected light, transmitted light, and cathodoluminescence microscopy. The principal impurities are quartz, calcite, aegirine, apatite, ankerite, magnetite, goethite, and synchysite [Ca(La,Ce,Nd)(C03l2Fj. Cathodoluminescence microscopy was found to be very useful in studying the character of the fluorite and especially for recognizing the presence of apatite and calcite impurities. Fluorite exhibits blue, calcite shows yellow, and apatite has white, light purple, and pink cathodoluminescence. The cathodoluminescent character of apatite varies with its geological environment and position in the orebody. The results of this microscopic study show that phosphorus present in flUorite concentrates occurs principally in binary locked apatite-fluorite particles. Successive fluorite cleaner concentrates contain progressively smaller amounts of locked apatite-fluorite particles. Free apatite has been effectively partitioned to the final tailings.

Jan 1, 1995

By Masaru Sakakibara, Ngo Tuan Anh, Mitsuo Nozu

"In the southern region of Vietnam and the southern United States, numbers of Deep Mixing (DM) columns have been installed to increase the stability of slopes and mitigate ground settlement. However, in some cases, there were some quality problems for in-situ cement mixing such as inclusion of unmixed lumps. According to the investigations by the X-ray diffraction analyses, electrical conductivity (EC) test, and careful observations of in-situ mixing quality, it has been observed that the existence of expansive soil and its high EC value cause the insufficient in-situ mixing. The countermeasures to address these problems have been taken.INTRODUCTIONIn South Vietnam, under the guidance of numbers of references and standards (Miki, 1998, JGS, 2000, Kitazume et.al., 2001, BS 2005), Deep Mixing (DM) has been used in recent years for soft clay improvement to increase the stability of slopes and to reduce consolidation settlement (Nozu 2005, Tung et.al., 2009, S. T. G. Peng et.al, 2009). However, at the initial phase of the DM operation, the authors have encountered some unusual phenomena such as (1) lower strength and inclusion of unmixed lumps (Figure 1), (2) less amount of up-heaved soil, and (3) sticking of large lumps of clay to the mixing blades. In regard to the above (3), Photo 1 shows one of the countermeasures against the sticking. By means of the placement of additional plates, the stuck clay has been reduced significantly.Subsequently, we have noticed that the quality of DM columns has not been so good, which meant that there have been some unmixed lumps in the column despite high cement dosage such as more than 300kg/m3. The authors also have encountered the similar incidents in Vietnam and United States during the deep soil mixing work. For example, Photo 2 is the core samples taken from the DM test column in northern Vietnam adopting cement injection during penetration (CIDP) procedure. To solve this problem, various tests and investigations have been performed so far (Nozu 2010, 2012)."

Jan 1, 2015

By Seth T. Reese

REPORTS received from operating companies by the Bureau of Mines, United States Department of the Interior, indicated marked progress in the reduction of injuries to employees in the coking industry in 1951 as compared with 1950. The fatality rate (0.14) per million man-hours of exposure declined 33 percent and was the second best performance since statistics on the industry were first collected in 1916. The nonfatal-injury rate (10.94), the best since 1940, declined 8 percent and was bettered only in 8 of the past 36 years. The nonfatal rate is based on all injuries resulting in loss of time for more than the remainder of the day on which the injury occurred. The exposure to hazard, as represented by the number of man-hours of work time during the year, was 7 percent higher than in 1950 and, except for the year 1943, was the highest since 1920. The fatality rate for men employed at beehive-coke ovens decreased 16 percent and the nonfatal-injury rate 23 percent, while the man-hours of work time or exposure increased slightly over 16 percent. The fatality and nonfatal-injury rates at byproduct ovens declined 33 and 2 ½ percent, respectively, while the number of man-hours worked increased 6 percent.

Jan 1, 1954

By Theodore M. Katz, W. Stephen Brightwell, David E. LeGrande, Joseph J. Hurrell, Jane A. Lipscomb, Nancy Lessin, Lawrence R. Murphy, Michael J. Colligan, Steven L. Sauter, Richard A. Lippin

Revolutionary changes in the organization of work have far outpaced our knowledge about the implications of these changes for the quality of working life and for safety and health on the job. This gap in knowledge is one of the 21 priority areas for research under the National Occupational Research Agenda (NORA)—a framework crafted by the National Institute for Occupational Safety and Health (NIOSH) and its partners to guide research into the next decade. This report was developed under NORA as the first attempt to develop a comprehensive research agenda for investigating and reducing occupational safety and health risks associated with the changing organization of work. Research and development needs identified in the agenda include (1) improved surveillance mechanisms to better track how the organization of work is changing, (2) accelerated research on safety and health implications of the changing organization of work, (3) increased research focus on organizational interventions to protect safety and health, and (4) steps to formalize and nurture organization of work as a distinctive field in occupational safety and health.

Jan 4, 2002

By Yongbao Zhu

The Ag2O-mediated reactions of cycloaurated compounds with a general formula Au(L)Cl2 (L = bi-dentate C?N ligand) with thiosalicylic acid, N-acetyl cysteine or 1,2-benzenedithiol in DMF proceeds via ligand substitution of the Au?Cl bonds to afford the S-O and S?S adducts all in good yields. The reactivity of the dichloro, S-O and S-S adducts towards thiols were examined by reacting with cysteine in an aqueous medium, revealing that all of Au-Cl, Au-O and Au-N are labile for thiol displacement. The measurement of the inhibitive activities of these compounds against human cathepsins B and K showed that the dichloro and S-O adducts are effective inhibitors with IC50 values ranging from 0.1 to 2.6 -M, and that the S-S adducts are inactive.

Oct 1, 2003

By W. A. Backofen, N. E. Paton

DEFORMATION twinning contributes to the plasticity of titanium and has been reported on {10i2}, {1121},{11221}, {1123}, and {1124} planes.' Twinning on {1011} has also been reported in commercially pure titanium as a result of quenching from 1000', but no reports of such twins occurring as a result of deformation alone are known to the authors. In this study single crystals grown from iodide titanium were compressed parallel to the c axis over the temperature range 25 to 800°C. From it has come evidence that (10il) deformation twins are the most common type between 400" and 800°C. Crystals about 6 mm high with a rectangular cross section measuring about 3 by 4 mm were used in the tests. Chemical analyses showed them to contain 220 to 250 ppm 0 arid 10 to 15 ppm N. The long axes of the crystals were made parallel to the c axis while the sides were parallel to (i100) and (1120), as shown in Fig. 1. The crystals were compressed between polished alumina platens with no lubrication, in a vacuum of 2 x lom5 torr. Between 25' and 300°C the predominant twinning mode was (11221, which is to be expected for this stress state. There was an abrupt change at 400°C, however, and from that temperature up to 800°C twinning took place almost entirely on (10i1 ). Twin planes were determined by the two-surface rnethd. Measurement of the crystal orientation within several (10i1) twins by means of polarized-light4 and transmission electron microscopy showed that the lattice reorientations were the same as those previously reported for the (10i l ) twinning in magnesium.' This reorientation is consistent with The calculated (10il ) twinning shear for titanium is 0.10, while that measured from surface offsets on a (1150) face, which is parallel to the shear direction, was about 0.15. Slip within the twins, or in the matrix adjacent to the twins, probably accounts for the larger measurement. Slip in both locations was judged to have occurred from observations on foils in the electron microscope.

Jan 1, 1970

By D. Almond

Low-grade, complex mineral deposits have resulted in the need for complicated large-throughput processing plants delivering increased productivity, reliability, and utilization, together with reducing operational costs. Complex mineralogy has resulted in complicated process flow sheets designed to recover minerals as efficiently as possible. In addition, the remote location of many minerals-processing plants, continuously rising energy costs, and fierce competition pose significant challenges to the modern mine, compounded by a global scarcity of qualified and experienced operational personnel. Over the last decade the Internet and automation technologies have undergone major advancements. Automation technologies, solutions, and concepts that existed, but were considered risky or unreliable prior to the year 2000, have now gained acceptance and matured. Furthermore, new technologies and different collaboration schemes have appeared, offering innovative solutions to the mining industry to address many of the challenges described. These advancements in reliable remote systems that access technology through the Internet provide significant opportunity to support mining operations, enhance process performance, provide engineering services, and proactively anticipate and execute maintenance services. This paper references a global survey of automation trends in the mining industry and the potential for an intelligent collaborative environment using automation technologies to exploit opportunities in operating the plant of the future, increasing effectiveness, and reducing operational costs. A variety of possibilities are described, including asset management solutions, remote access capabilities, performance monitoring solutions, advanced process control technologies, and the formation of an intelligent collaborative environment. A real example where this technology is used to support the operation and maintenance at a cement plant in Egypt is given to underpin the concepts described in this paper.

Jan 1, 2012

By Patrick R. Taylor

United States Antimony Corporation, at its Yankee Fork property in central Idaho, is currently using a combination of flotation, gravity-amalgamation, and concentrate cyanide leaching, silver sulfide precipitation, and activated charcoal loading to recover both silver and gold. Tine processes of flotation, milling, gravity concentration, amalgamation, concentrate leaching, sulfide precipitation and gold recovery via charcoal are discussed. The flow sheet illustrates the use of cyanidation as an alternative to shipment to a smelter.

Jan 1, 1984

By E. P. Youngman

This digest, based upon a translation" of certain portions of the 1930 law, covers the pertinent points of what has been termed "The New Mining Law of Luxemburg," the Grand Ducal Order (Arrêté) of April 26, 1930, concerning the exploitation of "mines, minières, and carrières, 4 and abrogating the order of January 2, 1891, concerning the same subject." The Duchy of Luxemburg, which between 1735 and 1815 was French, adopted as its basic mining law the French Law of April 21, 1810, and an Imperial Decree of January 3, 1813. The Luxemburg Government later supplemented and modified this legislation by the laws of June 12, 1874, April 30, 1890, and May 10, 1898, which, with article 36 of the Constitution, are to be taken into consideration in a complete survey of mining legislation. The order of

Apr 1, 1933

By Tim O’Neil

Nearly 4,800 mining professionals and exhibitors occupying 580 booths attended the 2000 SME Annual Meeting and Exhibit, Feb. 28-March 1, in Salt Lake City, UT. The technical program included80 sessions and four specialty symposia: bulk material handling, control 2000, minor elements 2000 and plant operaters. Meeting highlights included the keynote session. Executive shared their perspectives on pivotal issues and approaches to address the challenges of the new millennium. SME has begun planning for its 2001 Annual Meeting, Feb. 26-28, in Denver, CO. The meeting carries the theme “2001 — A Mining Odyssey.” A call for papers has been issued and exhibit space is 80% reserved. For information, visit SME’s website, www.sme-net.org. Or write Box 625002, Littleton, CO 80162-5002,ph 800 763 3132 or 303 973 9550, fax 303 979 3461, or email meetings@smenet.org.

Jan 1, 2000

By Earl R. Maize

Epoxy and polyester-type resins were injected into coal-mine roof strata of the thick Freeport coal seam in Allegheny County, Pa., at test sites in roof that had been exposed several weeks, in newly exposed roof, and in strata over solid coal. Test results indicate that the method of strengthening bituminous-coal-mine roof by injecting a bonding material into the roof strata can be developed into a safe, efficient support system. If roof bonding will become a standardized method of roof support and reinforcement or if it can be effective when used with other types of roof support can be determined only by extensive experimentation in various coal beds. Observations and conclusions are shown at the end of this report.

Jan 1, 1959

By O. Ozdemir

Soda ash, an essential raw material for major industries, such as the glass, chemicals, soap and detergents, pulp and paper, mining and water treatment industries, is traditionally produced by chemical and thermal treatment of trona ore. The treatment processes for trona ore are not only chemically expensive but also energy intensive. Hence, the production of a high-purity trona concentrate at a lower energy and operating cost is of considerable interest to the trona industry. In this study, we describe a possible two-stage process for concentrating trona ore, involving dry magnetic separation followed by flotation, to remove insoluble impurities from the trona ore. The results showed that a trona concentrate of 91.7% purity with a recovery 91.1% can be obtained by two-stage magnetic separation, which could be further improved to 98.1% purity at a recovery of 83.8% by subsequent flotation of the non-magnetic trona product. The purity of trona concentrate is limited by the particle size and impurity content of the trona ore. The operating parameters for magnetic separation and flotation have been identified to obtain an acceptable quality concentrate.

Jan 1, 2011

By Jon A. Hummer, Aleksandar D. Bugarski, Shawn Vanderslice, Teresa Barone

A study was conducted to examine the potential of diesel emissions control strategies based on retrofitting existing power packages with exhaust aftertreatment devices and repowering with advanced power packages. The retrofit systems, a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF), were evaluated individually using a US EPA tier 2 (ter 2) engine operated under four steady-state conditions and one transient cycle. The DOC effectively curtailed emissions of CO, and to some extent organic carbon (OC), elemental carbon (EC), and aerosol number concentration. The DPF system offered substantially higher reductions in OC and EC mass and aerosol number concentrations. Both, the DOC and DPF achieved reductions in the aforementioned emissions without adversely affecting emissions of NO2 and nano-sized aerosols. The strategy of repowering with an advanced system was examined using a US EPA tier 4 final (tier 4f) engine equipped with a cooled exhaust gas recirculation system and diesel exhaust fluid-based selective catalytic reduction system, but not with a DPF system. The tier 4f engine contributed substantially less than the tier 2 engine to the EC and OC mass, aerosol number, and CO, NO, and NO2 concentrations. The tier 4f engine was very effective in reducing aerosol mass, NO, and NO2 concentrations, but it was not equally effective in reducing aerosol number concentrations. The implementation of viable exhaust after treatment systems and advanced diesel power packages could be instrumental to the underground mining industry to secure a clean, economical, and dependable source of power for mobile equipment.

By AIME AIME

THE Engineering Education Committee of the Institute convened at the Engineering Societies Building on Feb. 18, .1929, with. E. A. Holbrook, dean of the Schools of Mines and Engineering, University of Pittsburgh, in the chair. STATISTICAL' STUDY OF STUDENTS IN MINING The first paper, a statistical study of the students enrolled in courses leading to a mining degree in 40 institutions, was presented by H. D. Keiser,, assistant editor of the Engineering and Mining Journal; who gave a brief outline of an article he was about to publish in ?that journal?. The complete article appears in the issue for March 30; 1929: To avoid repetition the results are summarized as follows: A request was sent to 42 institutions which give courses in mining' for the number of students enrolled as freshmen; sophomores; juniors, seniors and special students in mining for the years 1925-26, 1926-27, 1927-28, 1928-29. Two of these colleges replied that there were no students in mining. Students' enrolled in courses in metallurgy, geology and engineering, other than mining, were excluded from the statistics:. The statistics received were arranged in, four groups, according to the completeness of the information. One complete group of 25 institutions 'shows as follows:

Jan 1, 1929