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By R. E. Fryxell, E. C. Duderstadt, P. K. Conn

Permeation rates for nitrogen through are-cast tungsten were measured in the temperature range 1800° to 2600°C at nitrogen pressure differentials of 1.0 and 0.1 atm. Gas chromatography was used to measure the quantities of nitrogen which permeated through 0.26-and 0.53-mm-thick membranes. Permeation rates were proportional to the difference between the square roots of the nitrogen pressure on each side of the membrane and inversely proportional to membrane thickness, indicating that atomic nitrogen was the difjusing species and that diffusion was the rate-limiting step of the process. Permeation coefficients calculated from the rates may be represented by the equation: where P is expressed in the units cu cm (stP)-mm per 1/2 sq cm-min-atm"' and 70.0 * 0.8 is the activation energy in kcal per mole of permeating species. In a previous paper' permeation rates were reported for hydrogen and for oxygen through tungsten. The permeation cells used for the hydrogen measurements were suitable for measuring nitrogen permeation under similar conditions, so the study was extended to include nitrogen. Permeation rates of nitrogen through the polycrys-talline arc-cast tungsten membranes were measured in the temperature range 1800" to 2600°C using two membrane thicknesses and two nitrogen pressure differentials. Permeation coefficients were calculated and the activation energy of the process determined. THEORY For diatomic gases which dissociate prior to diffusion, the quantity of gas which permeates through a membrane or wall at an elevated temperature where bulk diffusion is the rate-limiting step of the process is given by the equation: where: q = total amount of gas permeating a membrane, P = temperature-dependent permeation coefficient, A = area of membrane, t = time, p1 = gas pressure of high-pressure side, p2 = gas pressure of low-pressure side, and d = thickness of membrane. When bulk diffusion is the rate-controlling step, and the solubility of the gas obeys Henry's law, a further relationship is that, for any given temperature and pressure, the permeation is the product of diffusivity and the amount in solution. The permeation coefficient, P, is temperature-dependent according to the equation: where: Po = permeation constant, Q = activation energy, R = gas constant, and T = absolute temperature. EXPERIMENTAL PROCEDURES Cell Design and Experimental Apparatus. Two of the permeation cells used for the previous measurements of hydrogen permeation are shown in Fig. 1. Each consisted of a cylindrical chamber divided into two parts by a permeation membrane fabricated from high-purity (>99.9 pct W) wrought tungsten sheet made from vacuum arc-cast tungsten. The membrane in one cell was 0.26 mm thick and the other was 0.53 mm. The fabrication of these cells was described previously.' The permeation cells were mounted vertically in a high-temperature tungsten resistance furnace and the membranes and the center portions heated to test temperatures. Temperatures were measured by sighting an optical pyrometer on the edge of the membrane through a small hole in a tungsten plate which was fastened to the side of the cell. This arrangement provided an approximate black-body condition and eliminated the need for emittance corrections. Appropriate corrections were made for the quartz window through which the temperatures were measured. Argon gas flowed through the 10-liter volume of the furnace at the rate of 4.7 liters per min. An impurity

Jan 1, 1969

By B. Seegmiller, W. A. Hustrulid, O. Stephansson

Introduction The concept of in-the-wall haulage was formally introduced to the mining community in the early 1970s. The basic concept is simple. Rather than the traditional in-the-pit haulage/access ramp, single or twin ramps driven in the pit wall are used with crosscut connections on the working levels. The in-the-wall pit haulage system could be considered as part of the opening of a new mine, a way of completing to final depth an existing pit, or part of the transition from open-pit to underground mining with the ramp remaining as part of the access. This paper is intended to acquaint the reader, particularly mine planning engineers, with some of the possibilities presented by the concept. Nordstrom (1983) said, "In many countries, mining engineers are either open-pit or underground specialists and, hence, often don't consider the possibilities for combining the best aspects of each into a hybrid mining system." This is believed to be true. There are few "hybrid mines" employing, for example, open-pit methods with underground haulage systems. One reason is the variance with the experience of the mining company and the engineers involved. However, with today's low metal prices, innovative and unconventional thinking may be just what a property requires to remain in production. All the possible situations where an in-the-wall ramp might be considered cannot be presented here. Rather, a few examples will be discussed for illustration purposes. Potential savings in stripping costs A major cost in open-pit mining is associated with the removal of overburden and waste rock. Although much of this stripping cannot be avoided, the volume (V) associated with the presence of an in-pit haul road can be quite large, V 100 (pit depth) a (road width) 2 x road grade (%) As an example, consider a vertical ore body 400 m (1312 ft) long, 60 m (197 ft) thick, extending to a depth of 160 m (525 ft). Cross sections are shown in Fig. 1. Other data are: ore tonnage = 11 Mt (12 million st), ore density = 2.9 t/m3 (0.09 st per cu ft), waste rock density = 2.7 t/m3 (0.08 st per cu ft), road width = 20 m (66 ft), road gradient = 10%, and level interval = 10 m (33 ft). The evaluation has been made assuming that the pit slope (0) is constant around the pit except on the side with the haul road. On this side, the slope is decreased to allow for the road. Slope angles of 30° to 60° have been selected to indicate the dependence of stripping volume (V) on slope angle. The stripping at the ends have been calculated assuming representation by cones. The volume associated with the haul road is 2.6 Mm3 (92.8 million cu ft). A comparison of the strip volumes involved is shown in Table 1. As can be seen, the percent savings in strip volume varies from about 4% to 17% and depends greatly on the slope angle. It is perhaps more interesting to examine the savings in stripping costs that could then be used to cover the cost of the access ramp and the crosscuts for stripping costs of $3/m3 ($0.08 per cu ft). The cost with the road volume is 2.6 million x 3 = $7.8 million.

Jan 1, 1988

By C. E. Coleman, D. Hardie, A. E. Wraith

A photoguaplric method of measuring crack velocities has been applied to an examilzation of- the effect of hydrogen on the impact properties of zirconium. Results indicate that the crack in hydrided zirconit travels at about 26 m per sec whereas that in the uacuum -annealed is dependent on the speed of the hammer. RECENT work on the effect of hydrogen on zirconium reveals that when hydrided zirconium is tested in slow bending the crack producing failure can be unstable. The mode of fracture seems to involve the crack linking up broken hydrides by a ductile mechanism in the zirconium matrix.2" In order to compare the fracture of zirconium with that of other metals which show unstable crack propagation, notably steel, the rate of the crack spread must be known. As the methods previously used for measuring crack growth are either unsuitable for the present work5-'' or very costly," a simple technique has been devised in which the maximum crack velocity is derived from a series of crack position-time measurements. EXPERIMENTAL PROCEDURE The experimental arrangement is shown schematically in Fig. 1. The flash unit12 was triggered when the Charpy hammer touched the specimen and the 6-psec flash of the lamp delayed by a preselected time interval in the range 100psec to 10 msec. The camera was left on open shutter during the test. From direct measurement on a calibrated photographic print, Fig. 2, the position of the crack and the specimen was found at a known time after impact and, from a series of such tests using an appropriate range of flash-delay times, the crack velocity was estimated. Preliminary experiments were carried out on mild steel above and below its transition temperature. Vacuum-annealed zirconium, and zirconium hydrided to 100 ppm H were then tested at 20" and 150°C. For comparison, Zr-2.6 pct Nb alloy (in the 0 + transformed /3 condition), vacuum-annealed or hydrided to 100 ppm H, was tested at 20 C. The chemical analyses of these materials are given in Table I. For the high-temperature tests a fine chromel-alumel thermocouple was spot-welded onto each specimen close to the notch. The test piece was heated up to 200°C to allow enough time for preparing the apparatus while the specimen cooled to the testing tem- perature. It was assumed that the specimen cooled uniformly. The accuracy of the flash-delay time was better than i2 pct i 5 psec. The crack length was taken as its maximum distance traveled normal to the length axis of the specimen. Errors in these measurements arise as a result of the uncertainty in the location of the crack tip and the difficulty in defining the exact position of the crack starting point. The latter was due to the bonding and large amounts of deformation at the hammer contact point, especially in the vacuum-annealed specimens tested at 150°C. The maximum error in the measurements was however estimated to be about 5 pct. DISCUSSION OF RESULTS From the trial experiments using mild steel above its transition temperature it can be seen from the plot of crack length against time after impact, Fig. 3. that a reasonable estimate of the maximum crack velocity at the surface of the specimen may be made. Other features of note are the initiation time before the crack is first seen and the slowing down period

Jan 1, 1967

By H. W. Becker, C. C. Frye, A. V. Degau, A. Masuda

Natural gas containing 25.65 per cent hydrogen sulfide and 4.75 per cent carbon dioxicle is gathered frorn eight \veih arid tratzsporrcd 26 miles at a flow rate of 160 MMcf/D and at operating pressures of frotrl 1,200 to 1,800 psig. Dry desiccant dehydrators at each wellsite tnaintaitz the dew point of the gas below 17F. Telemetering facililies permit control of field operations from a central instrunlent console. Corrosion control ineasures, design coilsiderations and material specifications pertainitz to these specia1 conditions are cliscussed. INTRODUCTION Natural gas containing 25.65 per cent H2S and 4.75 pcr cent CO, is produced from the Pine Creek field, Alta. It is dehydrated at wellheads, gathered at 2.200 psig and transported 26 miles to the Windfall field where it is delivered to the inlet of injection compressors at 1,800 psig. The daily average volume of gas transported is 160 MMcf. The project is believed to be unique in its combination of percentage of hydrogen sulfide, operating pressure and transportation distance. This paper describes the project and presents details of some of the design features, corrosion control program and centralized automatic operational control. The Pine Creek field project is one phase of a joint operation of two fields—thc other being the Windfall field. The two fields lie about 30 miles north of Edson, Alta. and 20 miles west of Whitecourt, Alta., respectively, as shown on the map (Fig. 1). They are owned by the same interests and operated according to a plan for maximum economic recovery of products. The Windfall Leduc D-3 reservoir contains a rich condensate-bearing gas containing 15.5 per cent HIS. The gas from the Pine Creek field contains only very small quantities of butane and heavier products. The Windfall reservoir is being cycled to obtain maximum condensate recovery using gas from the Pine Creek field as the displacing fluid, while producing the residue sales gas for both fields from the Windfall field. The Pine Creek field development and gas-gathering facilities are shown on the map (Fig. 2). The producing formation is the Leduc D-3 reef at a depth of 11,300 ft. The original reservoir pressure was 4,590 psia at 7,400 ft subsea and the temperature is 245F. Eight wells are equippcd with dry desiccant dehydrators with the following capacity ratings: three at 35 MMcf/D; three at 20 MMcf/D; and two at 10 MMcf/D. WELLHEAD EQUIPMENT Dry desiccant dehydrators were designed to reduce the water content of the saturated wellhead stream to 2.5 lb of water/MMcf at 2,000 psig. This specification was necessary to prevent hydrates and corrosion forming in the pipeline which will operate at temperatures as low as 20F. A typical flow diagram is shown in Fig. 3, and Fig. 4 is a photograph of one of the wellhead installations. Some of the design details given below are subject to modification in the field. The well-stream flowing temperatures range from 135 to 170F. Wellhead flowing pressures up to 3,200 psig are reduced to the dehydrator-operating pressure of about 2,100 psig by throttling through a pressure control valve. The gas is then passed through an aerial cooler where its temperature is reduced to 105F. thus removing over half

By P. H. Metzger, D. W. Fuerstenau

The activation of sphalerite was found to occur at a much lower rate with Pb++ then with Cut++ or Ag+. To prevent activation with Pb++, the ratio [m in solution must approximate 103. An example is given illustrating how this condition is met in practice through the addition of zinc sulfate and soda ash. In selective lead-zinc flotation, the mill operator, especially the one who is concentrating a partially oxidized ore, often must add zinc sulfate and/or soda ash for effective depression of the sphalerite. In the present paper the authors show how this practice prevents the activation of sphalerite in the presence of Pb++. A number of years ago Gaudin (1) postulated that Zn++ might control the activation of sphalerite with Pb++ through competitive adsorption. However, recent experimentation has shown the activation of sphalerite with Ag+ and Cut++ to be a chemical reaction in which silver or copper ions replace zinc in the sphalerite lattice through the formation of a more insoluble sul-fide (2,3,4) Thus, if activation with Pb++ is similar to that with Ag+ or Cu t+, zinc salts should control the activation of sphalerite not through competitive adsorption but because the ratio of [zn++/Pb++] in solution regulates the extent of the chemical exchange between Zn++ and Pb++ in the solid phase. The objective of this investigation has been to study the kinetics and equilibrium conditions for the uptake of Pb++ by sphalerite and to investigate the prevention of lead activation with zinc salts. BASIC PRINCIPLES Sphalerite activation has been shown to be a replacement reaction wherein a less soluble compound is formed at the expense of the more soluble zinc sul-fide (2,3,4) For example, if sphalerite is placed in an aqueous silver nitrate solution, ZnS gives to the solution more S= than can exist together with Ag+, and hence the following reaction takes place: ZnS + 2 Ag+? Ag2 S + Zn ++; k = [zn ++]/[Ag ++]2 = 10 26 (1) Therefore, ZnS will dissolve in the presence of Ag+ and activation of sphalerite with Ag+ will proceed after monolayer coverage by solid state diffusion until equilibrium conditions are reached in the system (2, 4) Because of the large difference in the solubility of ZnS and Ag2S, zinc salts cannot affect the reaction unless a complexing agent, such as cyanide ions, is present to complex Ag+ more tightly than Zn++ . By complexing Ag+ and Zn++ in solution, the uptake of Ag+ by sphalerite can be regulated by controlling the ratio m. . Experimentally (2) it was found that the activation of sphalerite by Ag+ could be prevented through the addition of NaCN if this ratio reached a value of approximately 10 26. The mechanism of sphalerite activation with copper salts is given by the following reactions: ZnS + Cu ++ ? CuS + Zn + + ; (2) k = [Zn++]/[Cu++] = 10 11 ZnS + Cu + ? Cu2S+ Zn++; (3) Experimentally Mao (3) found that the activation of sphalerite with Cu++ or Cu + was prevented if the ratios expressed in Equations 2 and 3 were approximately l09 and l022, respectively, with cyanide ions as the deactivator. Although zinc salts do not affect the activation of sphalerite with silver or copper ions in the absence of a complexing agent, activation with lead ions theoretically can be controlled by the addition of zinc salts because of the relatively small differences between the solubility of ZnS and PbS (5). Equilibrium

Jan 1, 1961

By M. A. Leosson, S. H. Bottrell, R. J. Newton

Sylvite at Boulby is mined 1 140 m beneath the sea and the mine suffers from the influx of water. This is of two kinds: persistent flows originating in the Sherwood Sandstone aquifer and entering the evaporite sequence through fractures in the intervening mudstone, and impersistent flows which are transient in nature and of uncertain origin. Water from the overlying sandstone has become enriched with NaCl and large amounts of KCl and some Mg and Br have been added by interaction with the evaporites. Waters from the transient flows are isotopically distinct from those in the Sherwood Sandstone, being enriched in H and O. They are also saturated with respect to halite and sylvite, but have higher K/Na than the persistent flows and are much more enriched in Mg and Br

Jun 18, 1905

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1980 (October 1, 1979 - September 30, 1980) under its Minerals Health and Safety Research program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1980

Demonstrate the technical feasibility of using nontraditional, low-rank, coal-based fuels and new coal-based technologies for mineral and metallurgical applications. Approach A cooperative research effort was initiated between the Bureau of Mines, U.S. Department of Energy and the minerals industry to extend the application of the fixed-bed gasification process to low-rank Western coals. The research effort enabled cooperators to gain operating experience in the use of hot, raw producer gas for iron ore pellet induration and other high-temperature mineral processes. Researchers were able to gather data regarding the fundamental engineering aspects of the fixed-bed process and gas cleanup for a wide range of solid fuel properties. Applying Fixed-Bed Gasification As a prerequisite to gathering the data needed for the study, the Bureau of Mines designed and installed, at one of its laboratories, a 6.5-ft-diam. single stage, fixed-bed, air-blown atmospheric pressure gasifier. The gasifier was coupled with a hot, raw gas combustion system and iron ore pellet in. duration kiln. The gasifier is rated at 1.5 ton/h capacity of bituminous coal.

Jan 1, 1987

Just as geophysics, in the form of 3D seismic and wireline logging, plays a key role in petroleum reservoir management, so too will geophysics play an important role in mining of coal, metals, and minerals in the 21 st century. The commercial and social imperatives driving greater use of geophysics are reduced costs, increased revenues, and enhanced safety. In short, superior utilisation of capital and management of risks. In relatively undeformed sedimentary environments it is possible to adapt petroleum-style 3D reflection seismic to image mines. This has been demonstrated most impressively in the Witwatersrand. Anglo-American, for example, completed a $1 million 3D seismic survey at Western Deeps in order to site a new $300 million shaft with confidence. Likewise, 3D seismic has gained rapid acceptance at Australian coal mines in recent years. Encouraged by these successes, metalliferous mining companies are supporting research in Canada and Australia, as well as South Africa, to adapt 3D seismic for more highly structured, metamorphic terranes. Because the mining industry is far more diverse than the petroleum industry in terms of commodities and geological environments, 3D seismic is not always cost-effective. A plethora of other geophysical techniques can be applied, many of which are employed in mineral exploration. Mine applications of geophysics differ from traditional exploration applications in two main ways: time scales and length scales are shorter, and boreholes are more plentiful. Borehole geophysical techniques therefore play a more significant role, both for logging and imaging. Logging systems detail the variations of in situ physical properties down the borehole at scales measured in centimetres, while geophysical imaging techniques can map features located tens or even hundreds of metres from the sensors. While geologists tend to think of boreholes in terms of chips and core, geophysicists perceive them first and foremost as access paths for instruments. Borehole logging has been employed at iron and coal mines for decades, mainly to accurately define ore boundaries in delineation holes. In base metal mines, Outokumpu implemented logging widely for orebody delineation in percussion holes in the 1980s. The benefit was a direct cost-saving, arising from substitution of core drilling with percussion drilling plus borehole logging. The practice has since spread to other companies. INCO, for example, defines nickel boundaries in blast holes at Sudbury using conductivity logs. The benefits are in the form of reduced dilution and enhanced ore recovery, flowing from a more accurate mine model. Density, natural gamma radiation, magnetic susceptibility, and conductivity are the principal metalliferous mine logging parameters because they can be recorded in both dry and water-filled holes. Sonic velocity is the premier geotechnical logging parameter, given its sensitivity to rock strength, stress, porosity, and degree of fracturing. Sonic is recorded routinely in exploration and geotechnical holes at coal mines. With the advent of slimline dipmeter, full waveform sonic, and optical and acoustic scanner tools, the role of borehole logging in geotechnical evaluations is expanding. Monitoring of strain and micro-seismic activity enhances safety during mine production. While qualitative interpretation of logs is adequate for stratigraphic identification or definition of boundaries, a wealth of quantitative information, eg density, can be derived from properly calibrated, repeatable geophysical logs. Moreover, geophysical logs can sometimes serve as surrogates for geochemical assays, and not only for magnetite and uranium. At OutokumpuÆs Kemi chromite mine, for example, gamma-gamma logging provides the basis for grade control. By reducing reliance on assaying, three benefits can be realised: reduced reliance on core drilling; lower core handling and assaying costs; and shorter turn-around times. Conventional downhole EM and borehole magnetics are used for near-mine exploration, and for ground sterilisation. Inco has enjoyed considerable success with borehole UTEM in the Sudbury Basin, for example, and Geopeko has applied three-component borehole magnetics successfully in the Tennant Creek area. Electrical techniques such as applied potential and magnetometric resistivity (MMR) are also finding application at mines. For higher resolution, borehole seismic, radio imaging, and radar have been invoked, with varying degrees of success, to delineate orebodies and map structures, or to geotechnically characterise the rock mass and identify hazards. Success mapping nickel sulphide shoots with borehole radar has been reported by WMC at Kambalda. There are no universal geophysical panaceas, and each mine imposes different geological, logistical, and economic constraints. Geophysics will not always be cost-effective. However, the greatest single impediment to expanded use of geophysics at mines has been the low level of awareness of geophysics on the part of most mine geologists, engineers, and managers and, equally, the limited understanding of mine geology and engineering exhibited by the majority of geophysicists. This myopia will be remembered as a 20th century affliction! Blue Sky areas for mine geophysics in the next ten years include integration of geophysical data acquisition with drilling, enhanced grade estimation and rock mass characterisation, and the incorporation of geophysical information into mine models using geostatistical techniques. All these advances will be predicated on an expansion of petrophysical knowledge.

Jan 1, 2000

By A. W. Khair

This paper deals with the evaluation of the interaction between rock and the cutting tool, and with methods for determination of workability, and abrasivity of rock. A description of instrumentation is included along with research on the wearing process of bit tips and pick consumption. Analyses of bit rotation, evaluation of cutting, normal forces and energy consumption is presented. Finally influence of the basic water jet parameters and water jet assistance on the cutting process of hard and abrasive sandstone is discussed.

Jan 1, 1995

By Arash Nikvar-Hassani, Lianyang Zhang

To address the drawbacks of the conventional portland cement/fly ash (PC/FA)–based cementitious material currently used in practice to construct pumpable roof supports (PRSs), a novel cementitious material has been developed based on geopolymerization technology. The novel cementitious material is comprised of two pumpable grout streams: Stream 1 is a slurry composed of pozzolanic material and high-calcium additive and stream 2 is an alkaline solution comprised of a gelling agent. Biopolymer has been added to the second stream to provide ductility to the geopolymer cementitious material. In the laboratory scale, systematic experiments have been carried out to investigate the viscosity, setting time, and uniaxial compressive strength (UCS) of the new cementitious material and develop the right recipe for field applications. By collaborating with industry and the National Institute for Occupational Safety and Health (NIOSH), full-scale PRSs have been constructed and tested. The results show that (1) the novel cementitious material based PRSs has much higher peak UCS and similar or higher residual strength than the conventional PC/FA-based PRSs; and (2) unlike the PC/FAbased cementitious material, the novel cementitious material shows good long-term durability with nocracking/disintegration when exposed to air.

Jul 1, 2023

By Manasi Wijerathna, D. S. Liyanapathirana

"Deep cement mixing is a popular soft ground improving technology that improves the bearing capacity and settlement characteristics of natural soil. When Deep Cement Mixed (DCM) columns are installed attached to each other in a wall configuration, the walls are capable of resisting bending moments and shear forces in the direction transverse to the columns. Therefore, installing DCM walls beneath the embankment slope perpendicular to the alignment of the embankment is a proper solution to prevent excessive lateral deformations of the embankment. Previous research studies have shown that failure patterns of DCM column walls are different to failure patterns of individual DCM column rows, under lateral loads. This study investigates the failure patterns of embankments where DCM column walls are located beneath the slopes, with respect to DCM wall strength, DCM column wall width and the spacing between DCM walls. 2D and 3D numerical models developed using the ABAQUS/standard finite element programme, were used in this investigation. Results show that the DCM wall strength and width of the DCM wall have a significant influence on the failure mode and the critical failure surface of the embankment. 3D simulation results demonstrate that the failure due to soil extrusion between columns was less pronounced in embankments improved with DCM walls, due to the interaction between the DCM walls and the surrounding natural soil.INTRODUCTIONEmbankments constructed over soft ground are highly susceptible to global slope failure and excessive displacements due to combined effects of vertical and lateral loads beneath the embankment slope (Zheng et al., 2009, Han and Gabr, 2002). The overall stability of the embankment can be significantly improved by improving the soil beneath the slope of the embankment using Deep Cement Mixed (DCM) column rows or overlapped DCM column walls (Jamsawang et al., 2015, Larsson and Broms, 2000, Topolniki, 2004, Broms, 1999). According to the literature, the improved ground experience different failure modes other than shear failure, such as separation of columns, overturning, shear failure along the columns or dowel action (Broms, 1999). Some of the failure modes reported by Broms (1999) are shown in Fig. 1. The ultimate failure mode depends on the geometry and the strength of the improved ground (Jamsawang et al., 2015, Kitazume and Maruyama, 2006, Kitazume and Maruyama, 2007)."

Jan 1, 1900

By Ali Kahriman, D. Adiguzel, R. Ulger, U. Akkaya

The environmental problems arising from ground vibration has been faced and discussed frequently in various industries such as quarry, mining, civil works, shaft, tunneling, pipe line and dam construction etc. where the blasting operations are unavoidable. This paper presents the results of ground vibration analysis induced by blasting during the construction of the Istanbul Kadiköy-Kartal metro tunnel. Different rock formations in this tunnel route which is 21.6 km in length were encountered during the excavation process by blasting. As a first stage, Hoek’s Geological Strength Index (GSI) values of rock units were determined by using inverse distance weighting method. The GSI values which were obtained from boring data were used when evaluate the data. GSI values were estimated by inverse distance method (figure 3) along with the tunnel route. Afterwards, ground vibration parameters induced by 21 shots which were made in different locations was monitored and passing routes of vibration waves determined. Weighted averages of GSI values were calculated according to distance of the regions where vibration waves passed. Multi regression analyze were made with using frequency, charge per delay, GSI and the distance between the shot point and monitor station. The main goal of this study is to investigate the relationship between ground vibration frequency induced by blasting and GSI.

Jan 1, 2011

By Anthony Konya, Calvin J. Konya

This paper will present this research which correlates the borehole pressure to variables such as the Young's Modulus and Tensile Strength of various rock types giving blast designers the ability to design a presplit to function in many rock conditions, including weak rocks such as siltstones and mudstones.

Feb 1, 2020

By Keith Cramer

As a leader in the development of metal extraction technology, Avecia continues to pioneer advancements for the processing of copper through leach, solvent extraction, and electrowinning of copper. From the initial patent of the second generation of oxime 5- nonylsalicylaldoxime in the 1970's; to the effective use of modifier technology; and development of computer assisted modeling programs, Avecia is driving SX technology to maximize extraction productivity. Keys to consider when advancing productivity are: 1) high quality, high performance products; 2) a responsive, partnering approach to technical service; and 3) tools to aid in the education of industry wide technical personnel with a view on continuous improvement. The focus of this paper is on the advancement of tools to aid in the education for optimization of processing copper through solvent extraction. One such tool is Avecia's own customized solvent extraction modeling program called MEUM. MEUM is currently used world wide to analyze plant operations, test ideas for improving operations, assist engineering companies in design, and to teach basic solvent extraction concepts. Recently MEUM has also been incorporated into a University setting. In the spring of 2000 Avecia worked with the University of Melbourne to integrate MEUM into their Mass Transport tutorial class. Students completed exercises to evaluate how operational changes affected a solvent extraction plant's performance. This paper introduces the basic functions of the program and discusses the successful implementation of MEUM into the University of Melbourne curriculum.

Jan 1, 2002

By Chee S. Theng

As the 2016 president of the Society for Mining, Metallurgy & Exploration Inc., I am pleased to present the 2016 issue of the Transactions of the Society for Mining, Metallurgy & Exploration Inc., Vol. 340. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of the American Institute of Mining, Metallurgical and Petroleum Engineers (AIME). Those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2016 Transactions contains some of the most interesting research and insights from the past year and features an international slate of authors spanning industry, academia and government. Papers include the latest findings from the U.S. National Institute for Occupational Safety and Health (NIOSH) and special-issue articles on process development testing. The 2016 Transactions consists of a total of 65 technical papers, encompassing all 21 papers published in 2016 in the Technical Papers Section of Mining Engineering (Vol. 68) and all 27 papers published in 2016 in Minerals & Metallurgical Processing (Vol. 33). Additionally, this volume contains 17 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All of the technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2016 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2016

By Chee S. Theng

As the 2017 president of the Society for Mining, Metallurgy & Exploration Inc., I am pleased to present the 2017 issue of the Transactions of the Society for Mining, Metallurgy & Exploration Inc., Vol. 342. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of the American Institute of Mining, Metallurgical and Petroleum Engineers (AIME). Those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2017 Transactions contains some of the most interesting research and insights from the past year and features an international slate of authors spanning industry, academia and government. Papers include the latest findings from the U.S. National Institute for Occupational Safety and Health (NIOSH), a special review article on Heap Leach Modeling, and articles from two Special Issues on Rare Earths. The 2017 Transactions consists of a total of 54 technical papers, encompassing all 21 papers published in 2017 in the Technical Papers Section of Mining Engineering (Vol. 69) and all 24 papers published in 2017 in Minerals & Metallurgical Processing (Vol. 34). Additionally, this volume contains 9 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All of the technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our Publications staff. As the 2017 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2017

By P Shead, M A. Tuck

Both climate and methane control have been a prime concern in the development of the workings within the Deep Soft seam at Harworth Colliery. This paper describes the numerous methods employed over the past 15 years to effect control over these two major environmental pollutants at Harworth and describes a future method of working which will enable the output levels required to be achieved, whilst effecting the required level of both climatic and methane control. Firstly, the paper gives a broad historical overview of the steps taken since 1981, when production started in the Deep Soft seam at Harworth Colliery, to effect control over the main environmental pollutants in the seam. Secondly, the paper details the results of planning exercises undertaken to assess the various options with respect to panel layout, to achieve environmental control in future production districts. Finally, the recommended method of panel design to achieve the levels of production required is detailed.

Jan 7, 1997

By W. G. Davenport

The flash furnace is used for smelting concentrate to (i) high-Cu matte and (ii) molten metallic copper. It is also used for converting solidified/crushed matte to molten metallic copper. This is flash converting. It consists (Table 20.1, Fig. 20.1) of: (a)tapping molten 65 to 72% Cu matte from a flash smelting furnace (b) granulating the molten matte to ?1/2 mm particles in a 103 m3/hour water torrent (c) crushing the granulated matte to 50 µm in a vertical roller mill (d)drying the crushed matte (e) feeding the dry particulate matte to a second flash furnace for oxidation converting to molten copper. In 2000, flash converting is being used by Kennecott Utah Copper (George, et al; 1995; Newman et al, 1998, 1999a,b). A second installation is being designed for the Chuquicamata smelter (www.outokumpu.com [October 12, 2000]), The potential uses of flash converting are: (a) as the second half of a flash smelting/flash converting coppermaking sequence (b) as a continuous converting alternative to batch submerged tuyere converting. This chapter uses our flash furnace matrix to determine the %O2-in-blast, industrial oxygen and oil requirements for converting solidified 65% and 72% Cu matte to molten copper. It then discusses choice of feed matte grade and other aspects of the process.

Jan 1, 2001

By Helênio Resende Silva Júnior

PT. Krakatau-POSCO coke making plant, located in Cilegon, Indonesia, is the results of the know-how and experience of Paul Wurth (PW) in coke making field. The plant has a capacity of 1,321,000 t/y of gross coke achieved by two coke oven batteries with 42 top charging Paul Wurth “Jumbo” ovens each. PW “Jumbo” oven with a useful volume of 78,92 m3 allows decreasing drastically the number of pushing/charging operation per day with a consequent reduction of the diffuse emissions. Gas treatment plant with a capacity of 88000 Nm3/h has been designed in collaboration with DMT GmbH & Co. KG, adopting the latest technologies with specific design know-how. PT. POSCO-Krakatau plant has been successfully commissioned and started-up in October 2013. The present paper will highlight the main technology features applied in PT. Krakatau-POSCO project for both coke oven and gas treatment plants.

Aug 17, 2017