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By Michael J. Jorgensen, Anoop Polsani, Khurram S. Khan

Riveting operations in aircraft manufacturing involves the use of power tools for manually drilling holes for the rivets, power drills for the setting of the holes for the rivets, as well as rivet guns to drive and set the rivets. To close the rivet, the rivet is driven against a metallic bar commonly called a “bucking bar”. The bucking bars are typically held firmly to increase the quality of the riveting, as well as keep the bucking bar from “dancing” against the metal piece being riveted. Thus, employees in aircraft manufacturing involved in riveting are exposed to hand-arm vibration from several sources, and epidemiological evidence suggests that vibration-related musculoskeletal disorders are associated with long term exposure to riveting tasks in the aircraft manufacturing of aircraft.1,2 Recently, tungsten technology has been introduced into aircraft manufacturing for bucking bars, which are heavier than traditional steel bucking bars of the same size. Rivet guns with tungsten pistons instead of steel pistons have also recently been introduced with the objective of reducing vibration exposure to the riveter. The objective of this study was to assess vibration characteristics of steel and tungsten bucking bars and rivet guns to identify the combination that simultaneously reduced the combined exposure to both the “riveter” and “bucker”. Methods Vibration (10g tri-axial accelerometer, Biometrics S2-10G-MF Series 2) was measured from eight experienced employees using seven different rivet guns on size 6 rivets, with the same person bucking for all subjects. Vibration was also measured on two different bucking bars for these same eight subjects, with the same person driving the rivets using the various rivet guns. The rivet guns consisted of three E4 steel piston guns with different RPMs (Guns A-E4, B-E4, C-E4), an E4 vibration dampened rivet gun (Gun D-E4D), an E3 steel piston rivet gun (Gun E-E3) and an E3 and E4 tungsten piston rivet guns (Guns F-E3T and G-E4T). The bucking bars were made of 90% tungsten (1694g) and cold-rolled steel (843g), and were the same shape and size. A two-way repeated measures analysis of variance was performed on the vibration (mean frequency weighted resultant acceleration) on both the rivet gun side and the bucking bar side, and mean rankings were used to assess the vibration simultaneously for the rivet gun and bucking bars to investigate which combinations provided the lowest vibration exposure. Results Frequency weighted resultant acceleration was significantly lower on the E3 tungsten (F-E3T) rivet gun than the E4 steel piston (B-E4) and the E4 tungsten piston (G-E4T) rivet guns (Figure 1). When measuring vibration on the bucking bar, the E4 (A-E4) steel piston rivet gun resulted in lower vibration on the bucking bars than the E4 tungsten piston (G-E4T) and E4 vibration dampened (D-E4D) rivet guns (Figure 2). Additionally, use of tungsten bucking bars resulted in a 35% decrease in resultant frequency weighted acceleration than when using steel bucking bars.

Jan 6, 2006

By D. M. Davidson, P. F. Kerr

The Permian Cutler Formation in Kane Creek, Utah bears uranium ore in fissure-type vertical veins. This fissure vein formation and its associated host rock bleaching, weak argillic alteration, and base-metal sulfide mineralization along with the development of hydrothermal minerals, a 60 m.y. isotopic Pb/U age, and well-crystallized uraninite's structural control, give evidence of ore deposition in a hydrothermal environment consistent with Laramide mineralization. Mica polymorph studies indicate first, that temperature during the hydrothermal alteration or subsequent ore deposition did not exceed 200°; hence Cutler deposits are classified telethermal; and secondly, that rock alteration and ore deposition are closely related both in time and space, as is seen in argillic alteration sequence. Ore deposition in an alkaline to slightly acid reducing environment is postulated. Ore textures and mineral associations and distributions also indicate that carbonate complexes may have been transported with the deposing ores. Bleached rock formations are not primary strati-graphic phenomena. Bleaching, or changes in ferric iron content, results from a chemical process involving reduction and conversion of hematite to a soluble aqueous ion. Nearby Chinle bedded deposits (Moss Rack sandstone), containing shale lenses, fossil wood, organic debris and minor fractures, overly the Cutler formation. Chinle ores have a single reported isotopic age of approximately 200 m.y. Their chemical environment is assumed similar to that of the Cutler ores, though slightly more acidic. Two genetic, paradoxically divergent interpretations of the bedded deposits are derived from available spectrographic, petrographic, X-ray and chemical analyses. Kane Springs canyon is located southwest of Moab, Utah, south of the Colorado River and northwest of the Lisbon Valley mining district (Fig. 1). Uranium deposits occur along the northeast flank of a Kane Creek salt anticline where two geologic formations bear ore, the Permian Cutler and the Triassic Chinle. The Cutler deposits' fissure vein formation is an unusual occurrence in the Colorado Plateau. The Chinle deposits appear to be of the normal sedimentary type. Associated with the vein deposits are a number of features, including argillic alteration of sedimentary strata. The minerals of these deposits and their associated features have been studied in detail in a two year program entailing both field and laboratory techniques. STRATIGRAPHY A stratigraphic section of the lithologic units in the Kane Creek area is given in Table I.

Jan 1, 1967

By Lon A. Williams

This appendix contains drawing lists and drawings of components and assemblies designed for the prototype portable and machine mounted lighting systems per Tasks II & IV of Contract No. H0220065.

Jan 1, 1976

Good morning ladies and gentlemen, and may I thank you for inviting me once again to address your conference. I would first like to welcome you all, especially international delegates and conference speakers. ItÆs a pleasure to be with you all and I hope that you have the time to enjoy the many beautiful sights that the Coromandel and Bay of Plenty have to offer.   Holding your conference in Waihi is particularly apt, especially bearing in mind the conference theme û 'Mining in the Community'. There can be few venues in the world that can boast a world class gold deposit of the likes of Martha Hill located right here in the centre of a rural service town. ItÆs a deposit that has a mining history active now in its third century and that to date has yielded some 7.5 million ounces of gold and 50 million ounces of silver. I doubt that when John McCombie and Robert Lee discovered gold at Martha Hill in 1878 that they had any inkling that their endeavours would be the foundation for a mine that would become such an inseparable part of the economic and social fabric of Waihi for the next 130 years.   This is now my fifth appearance at a New Zealand minerals conference, I especially value such occasions as it allows me to comment on your industryÆs performance over the past year, share my thoughts on matters affecting your industry, and also to give you some feedback from central government.

Jan 1, 2006

By Gerald W. Longenecker

For decades, traditional hydraulic engineering approaches have been used for sizing stream channels when stream relocation efforts have been necessary to allow for the advancement of quarry and other surface mining operations. These approaches have been based on various ydraulic models to design channel cross sections and slopes that could pass the required regulatory design storm such as the 2-, 5, lo-, 25-, 50-, or even loo-year events. Designing the stream channel to handle these more extreme ,storm events would often lead to large channel designs which required extensive bank and channel bottom stabilization techniques including concrete, rip rap, gabions, or other expensive approaches. The constructed channels often required ongoing maintenance to remove accumulated sediment and other debris which would settle out and reduce the hydraulic capacity of the channel.

Jan 1, 1998

Various reagents are added to flotation pulps to manipulate the chemical environment in order to create favourable conditions for the separation of the desired mineral from the unwanted gangue. Interactions occur between these reagents and between the other chemical parameters existing in the flotation pulp which complicate the elucidation of the behaviour of the respective reagents. This paper discusses the roles of the main classes of reagents added viz. collectors, frothers, depressants and activators, as well as the interactions between frothers and collectors. A case study reporting synergistic interactions between thiol collectors in the flotation of pyrite at pH = 4 is included. The use of Potassium n-butyl xanthate (PNBX) and a dithiocarbamate type collector (DTC) were tested both as pure collectors and as components in a collector mixture. In the batch flotation tests sulphur recovery and grade, water recovery, rate of recovery and image analysis of the surface froth were used to evaluate the effect of the mixture on the overall flotation performance. Bubble loading tests showed that the use of the mixture improved the efficiency of the particle collection process by bubbles. Thermochemical measurements of the adsorption of the collectors onto the mineral, indicated the formation of different surface products by the two collectors.

Jan 1, 1998

By Leonard Weixler, Peter Halbach, Michael Jarowinsky, Johannes Post

Germany as an industrial nation is highly dependent on the import of mineral or metal resources. Sources which have not been considered until now are the marine mineral resources (MMR), which in recent times are enjoying more and more increasing interests and which might provide in the future a considerable contribution to the supply security on metal resources not only for the industrial countries. Backed up by the German government’s "National Masterplan Maritime Technologies" (NMMT) and corresponding industrial R&D-activities, the idea and the advantages of deep-sea mining is gaining more and more interests and supporters with respect to industrial and political considerations on strategic raw material resources as well as on the development of deep-sea mining technologies. The NMMT aims to initiate growth and increase the competitiveness of the German maritime industry on international markets and covers about 10 different marine and ocean technology sectors including deep-sea mining.

Sep 1, 2014

By P Minkkinen, J Lohilahti, T Korpela, B McPherson

Concentrator plants intake the ore from the mine and produce concentrates by extracting valuable minerals in a succession of process steps. Controlling the extraction process and detecting changes in the process requires updated information on a minute basis. Moreover, due to economical reasons, one must also collect metallurgical samples on a daily basis for monthly reporting.In this paper, we present how slurry samplers were installed in a Cu-Ni flotation plant to accomplish the aforementioned tasks. An on-stream elemental analyser at the plant is used for flotation process control by taking samples from selected process streams. Two process streams, the flotation feed and tail, are also equipped with metallurgical samplers. The metallurgical samplers were designed to have low head loss, be robust and easy to maintain and to collect slurry samples in a reliable way for the metallurgical accounting.Samples were collected by different sampler types and we discuss the uncertainty arising from sampling in the assays. Variographic analysis was carried out on the process data in order to find periodic components in the process, and estimate the correct number of shift sample increments and measurement error components. The metallurgical samplers were proven to be reliable devices with zero downtime and no sanding issues in the main process flows. In addition, we show that the tail measurement is the most important one for the plant recovery calculation, which emphasises the importance of the sampling accuracy in the tail stream.CITATION:Lohilahti, J, Korpela, T, Minkkinen, P and McPherson, B, 2014. Analysis of slurry sampling arrangements at a froth flotation plant, in Proceedings Sampling 2014 , pp 91–98 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By Charles S. Robinson

INTRODUCTION Geology, the science of the earth, is the fundamental science in the construction of a tunnel. The approximate site of a tunnel is determined by its purpose. The geology of the tunnel site will determine the cost--or feasibility of a tunnel--the specific alignment to accomplish the purpose of the tunnel, the design of the tunnel (within the limits of the purpose of the tunnel), and the methods of construction. The more accurately the geology of a proposed tunnel can be depicted, the more accurately can the cost of a tunnel be estimated. The factors that should be defined for tunnel design and construction are the physical characteristics of the material in which the tunnel is to be constructed. The physical characteristics of the material are determined by the genesis of the material, and subsequent geologic processes that have affected the material. The geologic materials in which tunnels are constructed can be broadly classified as unconsolidated and consolidated. The unconsolidated materials include chiefly deposits of recent geologic time that occur near the surface. Because these deposits occur near the surface, and tunnels constructed in them will be at shallow depth, methods of physical exploration such as geophysical methods, trenching, and drilling will give more data at relatively low cost--therefore the physical exploration is generally, or should be, quite extensive--and the

Jan 1, 1997

The income of the Institute is derived from dues, subscriptions to MINING AND METALLURGY and sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for especial purposes. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing committees in each case. An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization and at a minimum of expense. J. V. W. Reynders is chairman of the Endowment Committee.

Jan 1, 1923

This paper discusses support requirements for the proposed monorail system to be used in decline development. The monorail drilling and loading systems are systems that move on the rail (monorail) installed in the roof of the decline and supported by roof bolts, suspension chains and steel supports. However, due to the weight of the components of the two systems, it is imperative that the force in each roof bolt, suspension chain and steel support capable of suspending the weight of the heaviest component is determined. Numerical models that relate the weight of the monorail drilling and loading components to the required strength in the support system have been developed. Using these developed models, numerical values of the forces in each roof bolt, suspension chain and steel support, required to suspend the weight of the heaviest component of the monorail drilling and loading systems are determined.

Dec 6, 2010

By J. E. Dutrizac, J. B. O'Reilly

"Zinc is a relatively abundant element which occurs as both high-grade sulphide ores {sphalerite ZnS) and oxide ores which the ancients collectively termed ""calamine"" (smithsonite ZnC03 and/ or hemimorphite Zn4Si201(0H)2 - H20 and/ or hydrozincite Zn5(C03) 2(0H)6). Although oxidic zinc is readily reduced by carbon, the process becomes thermodynamically viable only at - 1000°C, and at this temperature the zinc is released as a vapour (B.P. 907°C). Casual cooling of the vapour results in its re-oxidation by excess combustion air or even the carbon monoxide product of the reduction reaction. ZnO + C = C09,, + Zn vapom Only fairly rapid quenching of the zinc vapour and the isolation of the reduction products from the combustion gases will yield metallic zinc; these conditions were not produced deliberately until the advent of distillation technology. Until quite recently, the principal use of zinc was in brass manufacture; galvanized iron was not discovered until the 19th century and zinc casting alloys are a relatively recent invention. As will be seen, brass could be produced without recourse to a pure zinc intermediary, and the discovery of brass preceded that of zinc by many centuries. The purpose of this paper is to outline the discovery and early development of both zinc and brass with special reference to the European scene."

Jan 1, 1999

By K. B. Higbie

The quantitative separation of tantalum from columbium has been obtained through several liquid-liquid extraction processes. The valuable metals are separated by selective extraction from organic feed solution using a mineral acid or by selective extraction from aqueous feed solutions employing an organic solvent. The greatest degree of separation was obtained when organic ketones, particularly methyl isobutyl ketone, were used. Approximately 200 combinations of various organic solvents and mineral acids were tested as possible separation systems in which the tantalum or columbium content was extracted from organic solutions of the anhydrous pentachlorides.

Jan 1, 1956

By Eric E. Ungar

Some fundamental facts regarding noise are summarized. Guidelines for reducing plant noise are indicated, and simple means are discussed for determining, whether quieting of specific equipment items will reduce plant noise significantly. Design and installation recommendations are made for quieting chutes by means of dams, impact cushioning pads, impact shields, and damping materials, and for quieting; screens by means of resilient decks, lined screen bottoms, drive mechanism enclosures, and side plate additions. A brief account is appended of the wear and productivity performance of resilient materials observed in three cleaning plants.

Jan 1, 1976

By Lyman Moore

This Bureau of Mines report describes 2nd evaluates iron ore resources in California and Nevada and analyzes the California and Japanese iron ore markets in which these resources will be used. The competitive position of California-Nevada ores, in these markets, was estimated by comparing regional iron ore prices, production costs, and transportation costs with those of foreign suppliers. Resources were determined to be sufficient to produce the equivalent of 585 million tons of 64-percent iron pellets at a price of less than $15 per ton delivered at California ports. Much higher tonnage could be produced at higher prices. Iron ore requirement of the California iron and steel industry will increase to an estimated 15.9 million tons by the year 2000. A study of the iron ore production potential of California-Nevada deposits and of out-of- State sources indicated that this ore requirement can be supplied most economically by California-Nevada ores. Iron ore import requirements of the Japanese iron and steel industry will increase to an estimated 150.0 million tons by the year 2000. A study of price trends in this market indicated that very little California-Nevada iron ore will be sold in Japan after 1973 when existing sales contracts expire. Iron ore-exports might be economically possible if ore could be transported from California to Japan at ballast rates as backhaul on existing petroleum shipping.

Jan 1, 1971

By L. R. Stark

Two wetland simulation experiments were carried out in order to determine the effects on manganese retention of several wetland design parameters, including flow rate, inlet pH, carbon supplementation, substrate type, and surface free water depth. The primary aim in each experiment was to determine if sustained manganese retention could be accomplished under the specific experimental treatments. If successful, these experiments could recommend design parameters for the construction of field wetland systems for manganese treatment. Crushed limestone clearly was superior to spent mushroom compost with respect to manganese retention. The presence of free surface water detracted from manganese treatment, while lower flow rates enhanced manganese treatment. Sustained manganese retention was achieved using crushed limestone as the substrate coupled with an absence of surface free water, under inlet water conditions of pH 7.0 and no appreciable iron. Sustained manganese retention was not achieved under reducing conditions using spent mushroom compost while varying flow rate, inlet pH, and carbon supplementation regimes. However, lowering the flow rate resulted in many significant beneficial effects on outlet water chemistry: lower outlet manganese concentrations (over the short term), higher outlet pH, lower outlet acidity, higher outlet alkalinity, higher outlet sulfide, lower outlet sulfate, and lower outlet redox potential. Supplementation of the wetlands with dairy whey resulted in lower outlet manganese concentrations (over the short term), marginally higher outlet sulfide levels, and acted to lower the redox potential under the high flow regime. Wetlands receiving a neutral pH had lower outlet acidity, higher outlet alkalinity, lower outlet sulfate, but equivalent outlet manganese concentrations than wetlands receiving an acidic pH. When manganese is the primary mine water contaminant and a passive water treatment system is to be used, it is recommended that crushed limestone with negligible surface water be used in place of composted materials. This recommendation assumes a source water with circumneutral pH and an absence of other metals.

Jan 1, 1993

By Alex C. Smith, Thomas A. Gray, Lynn M. Crayne, Michael A. Trevits, Phil Glogowski

Mine fires constitute one of the greatest threats to the health and safety of those working in the underground environment and each event has the potential for disastrous consequences. Of the major mine fires and thermal events that have occurred in the United States in the last 6 years, it is estimated that remotely installed seals could have been used in 63% of the events to control fire growth or to aid in fire suppression work. The National Institute for Occupational Safety and Health (NIOSH) is conducting full-scale tests at the NIOSH Lake Lynn Experimental Mine to evaluate and improve remote mine seal construction technology. The main focus of this work is to develop reliable technology that will completely close the mine opening from floor-to-roof and rib-to-rib. This paper presents the results of remote seal installations using grout-based materials.

By Charles Pretorius, Henk Ludik

Navachab Mine experiences difficulties with pit wall stability in certain areas of the mine. The main reason for the instability is the fact that the geology comprises many joints and faults. Blasting, without impacting negatively on the stability of the pit walls, poses a major challenge.

Jan 1, 2006

By Corale L. Brierley

Accumulations of microorganisms in the in-situ leaching environment are believed responsible for plugging of the orebody and thus decreasing uranium extraction. To assess the contribution of microbial growth to this problem, packed columns of ore and core specimens were leached in the laboratory. Samples collected at four in-situ uranium mining operations revealed pseudomonads, xanthomonads, Bacillus sp. and Micrococcus sp. in numbers of 105 cfu/ml. These microorganisms, inoculated into simulated leaching conditions, decreased permeability in two uranium ores by one order of magnitude in 20 days. Hydrogen peroxide (0.2 g/l) alleviated microbial plugging in the laboratory. Periodic injection of hydrogen peroxide through the production well into the orebody may reduce microbial plugging problems in the field.

Jan 1, 1982

By N. Kumar Kittusamy

A field study was conducted to evaluate seat designs on shuttle cars. Eight operators participated in evaluating seat designs on the basis of perceived levels of vehicle jarring/jolting and discomfort. Researchers also measured the levels of vehicle jarring/jolting. Four basic seat designs were compared on low and mid-coal seam shuttle cars during production operations at two underground coal mines. Two seats were currently used on the shuttle cars and another two were NIOSH designs. Objective data were collected using accelerometers with pre-amplifiers and filters connected to a data recorder; whereas subjective data were gathered with a visual analog scale (VAS) and a questionnaire. Results from measured levels of jarring/jolting showed that the NIOSH Seat L2A smoothed out bumps better than any other seats. Using the VAS, mid-seam and low-seam shuttle car operators rated the levels of jarring/jolting and discomfort lower with the NIOSH seat than the other seats. Questionnaire responses indicated that operators rated NIOSH seat designs as more comfortable. This research will provide the industry with better seat designs for isolating jarring/jolting in vehicles. Furthermore, researchers plan to improve the NIOSH seats using information gathered in this study.

Jan 1, 2003