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By Leon Eliel

TEN years ago a broad knowledge of aerial mapping, coupled with a smattering of geology, qualified one to speak on the subject of the appli-cation of aerial mapping to geology. Today, with aerial maps a common tool in the hands of expert geologists on every continent throughout the world, it would be nothing short of presumptuous for the author of this paper, who is not a geologist, to give any geological statements on his own authority. Relatively, today we are only purveyors of general geological gossip, with a definite case here and there by way of illustration. But we can present a story of the really marvellous strides that have been made in the evolution of aerial mapping, built around a skeleton of geological tidbits, from which some useful conclusions may be drawn. The average geologist goes about reading his aerial maps much as one would approach the problem of deciphering a cryptogram. To begin with, typical key expressions appear in recurring sequences and under certain conditions. If once the meaning of these isolated bits of infor-mation can be ascertained, the message begins to take meaning. In a similar fashion, the geologist works out his key from aerial maps of territory with which he has some familiarity. He learns that a certain type of thin, white line may mean a vein of quartz. He sees that a certain change in the photographic tone of vegetation on the ground reflects two kinds of soils on opposite sides of, a contact. He sees that a certain type of alignment of topographical features often means a fault. He learns that by the erosion pattern .he can frequently distinguish soft formations from harder ones. And so, bit by bit, he ties together the information of the picture with his experience on the ground until he develops a reasonably creditable capacity of interpretation. Through the complete gamut of surface conditions, ranging all the way from flat, arid, exposed desert terrain to dense jungle, or rugged mountains, the evidence from which the geologist must make his inter-pretation varies with bewildering profusion. The quality of photographs which are obtainable may range from perfect pictures in the desert to almost useless smudges in the steaming jungles. One thing he has learned with certainty-the airplane carrying its mapping camera is a superb reconnaissance tool, only awaiting his ingenuity in correlating the pictures with the ground to simplify most exploratory problems.

Jan 1, 1936

By Hang Zhao, Xinping Li, Pingan Wu, Yi Luo

"The deep-buried rock surrounding the Jinping II Hydro-power Station was taken as the engineering background. Using model specimens of classified rock materials to simulate fractured rock mass under high in-situ stress conditions, the test about acoustic propagation law on single fracture model of specimen under different pressures and different angles were carried out. The variation of p-wave velocity in fractured rock mass and axial stress-strain relationship in the whole test procedure was also studied. Based on damage mechanics principle and the acoustic wave propagation in cracked rock mass, comparative study on damage constitutive relation of fractured rock mass under high in-situ stress in consideration of equivalent strain and equivalent energy was performed. As the results showed, with the change of axial stress level under constant confining pressure, the change in wave velocity can be divided into three stages: slow increase (small variation in amplitude), rapid reduce (large variation in amplitude ) and accelerate reduction. When the confining pressure is constant, the maximum p-wave velocity and the peak strength of specimens increases with the decrease of the crack angle.When the crack angle is constant, the maximum p-wave velocity and the peak strength of specimens increases with the increase of confining pressure.It is identified that the theoretical calculation results of constitutive relation about elasto-plastic damage model containing variable wave velocity in the fractured rock mass is consistent with the model test results.Therefore,the constitutive relation can provide reasonable suggestions for engineering practice. INTRODUCTIONThere are a lot of joints and fractures in surrounding rock mass of deep-lying in the Jinping-II hydropower station, which has a great influence on the physical and mechanical properties of rocks and effects the acoustic wave propagation and attenuation law in rock. Many previous research and project examples has proved that sound propagation parameters are closely related to crack and stress condition. Thus, it has certain theoretical significance and practical application value to carry out researches on sound propagation characteristics and establish damage constitutive model of fractured rock mass which is related to sound propagation parameters."

Jan 1, 2015

By V. O. Tenorio, P. P. V. Coronado

"INTRODUCTION Productivity in Open Pit mines depend on the observation and adjustment of critical phases of operation. As one of the most expensive activities in Open Pit production, optimization of the load-haul-dump cycle becomes a critical aspect to address. Using simulation techniques and an ad-hoc methodology for analyzing the Key Performance Indicators (KPIs) involved in the production cycle, it is possible compare actual performance and ideal operating conditions and develop an alert system when operating conditions are sub-par with the expected production standards. STUDY OBJECTIVES The purpose of this work is to implement a methodology for optimizing the haulage cycle by identifying and adjusting the factors that affect the cycle time performance. The methodology includes the implementation of an alert system emitting warning messages when one or several trucks are idle or the time of completing production tasks is falling outside a predefined value. This alert is compared with pre-defined Key Performance Indicators (KPIs) and determine corrective actions: • Demonstrate the benefits of time analysis and how this affects the productivity results in the mining process; • Demonstrate the utility of KPIs in the extraction of ore and waste, and how they help to identify equipment performance; • Develop software interfaces to visualize the Alert System in order to increase awareness in the operations supervisor; and • Make recommendations for future applications that can help improve the productive process of an Open Pit mine. PROBLEM STATEMENT Transporting material in Open Pit mines may require the utilization of high capacity equipment, which also represents an elevated cost per hour. A supervisory system that controls the adequate distribution of trucks and shovels by providing the operational status of each unit shall contribute to increase productivity and subsequently reducing operational costs. Nevertheless, there is an issue with certain dead times such as queue trucks for loading, trucks waiting to be loaded, and other delays. This creates inefficiencies in fuel consumption and energy utilization. For the identification of delays, a context-based system could be required in order to help optimizing the haulage cycle time by controlling delays in loading, haulage, and dumping. After applying this methodology, efforts were focused in correcting out-of-standard performance values."

Jan 1, 2016

By B K. Da, S A. Balaji, G P. Roy, T K. Dutta

The raw material handling complex at the Durgapur steel plant provides iron ore, crushed coke and flux to two sinter plants. Either some facilities were not envisaged or not properly designed before the project stage which caused problems during operation of the plant. The absence of an in situ roll turning facility, used to increase maintenance activities for disassembly, transportation of rolls to central machine shop and assembly of rolls, led to decreased crusher availability and increased activities for the maintenance crew. The provision of a smaller vibro feeder/screen in place of a suitable sized screen caused jamming of the screen deck, adversely affecting screening efficiency and the crushing index of crushed coke. Some design modifications and developmental work was undertaken, such as the development and installation of an in situ roll turning facility in the existing limited space, achieving low feed (0.1 - 0.2 mm/rev), lower cutting speed of 30 - 40 m/minute for 350 BHN hard roll, which was also a difficult engineering challenge to bring within the tolerable limit of vibration. This was successfully achieved. Modifications to the screen deck, introduction of differential speed crushing and modification to the vibro screen and vibro feeder for uniform distribution of feed have been incorporated. These innovative design modifications to the in situ roll turning have led to a drastic decrease in maintenance activities and an improvement in the crushing index. Modifications to the screen have resulted in the elimination of jamming and improved screening. Modifications to the vibro screen before the primary crushers and to the vibro feeder before the secondary crushers have prevented excessive wear in the central portion of rolls, ultimately leading to increased roll life. Incorporation of differential speed crushing has resulted in an increased crushing index and decreased generation of micro fines. All the above modifications have led to distinct improvements in equipment availability, increased roll life and a decrease in maintenance activities and improvement in crushed coke granulametry, ultimately resulting in improved productivity and quality of iron ore agglomeration at the sinter plant. The innovative design modifications mentioned above are discussed in detail in this paper.

Jan 1, 2005

By R. V. Ramani

"Exposure to respirable contaminants in mine atmospheres has long posed a serious hazard to miners. The control of these hazards, some of which can have sudden and catastrophic effects and some others, slow and long enduring consequences, has been a major concern for labor, management and government alike. This concern has manifested itself in four primary mechanisms of control -- (1) regulatory control through minimum standard setting by the passage of mine health and safety laws, (2) engineering control through design and operation of 'mines according to the best recommended practices, (3) medical control through periodic physical examinations, wearing personal protection devices, etc., and (4) legal and social control through workmen's compensation laws for occupation related health deterioration:-The respirable contaminants in mine atmo¬spheres are toxic and explosive gases, toxic and explosive dusts, diesel exhaust particu¬lates, radon progeny, etc. Perhaps the most important of all these and the most widely occurring in mine atmospheres is respirable dust, an inevitable product of fragmentation, a unit operation fundamental to all mining operations. In fact; the-most serious health hazard for workers in the mining and minerals processing industries is still the exposure to respirable dust, and solutions to the problem of respirable dust disease remain to be found.The 1969 Coal Mine Health and Safety Act and its provisions for the respirable dust standards in underground coal mines are briefly reviewed. An overview of the research accomplishments in meeting the standards is presented. The current state of knowledge on the effectiveness of the standards and the new and emerging problems are discussed. A brief summary of the research programs of the Generic Technology Center on Respirable Dust is presented.In general, underground mines are becoming increasingly safe. The mine atmospheric environment is definitely improving * Professor and Head, Department of Mineral Engineering,-The Pennsylvania State University, University Park, PA for the better. Significant progress has been made in lowering the dust levels in mines. It is generally agreed that mines are less dusty today than they were a decade ago. However, as long as the risks of occupation-related diseases are not completely eliminated, vigilance can hardly be relaxed, and the search for engineering solutions must be intensified."

Jan 1, 1988

By David E. Hardt

"One of the critical variables to be controlled during arc welding is the size or geometry of the weld pool. The measurement of pool geometry has become an increasingly important problem with the advance of welding automation and control, and this paper addresses that problem. The basic concept of pool size estimation via measurement of pool dynamics is presented. The theory underlying this concept is discussed and is followed by a review of the current work in this area. It is concluded that pool dynamics can be characterized by natural frequencies of oscillation, for stationary welds, and that these can be measured by appropriate signal processing performed on the arc voltage. However, it appears that only full penetration welds show a strong correlation between weld size and natural frequency. Also, the extension of these results to the realistic case of moving welds has yet to be considered in detail. Nonetheless, this method of in-process measurement for real-time weld process control is still quite attractive where applicable since it can be accomplished simply by modifying the arc current schedule and by signal processing of the arc voltage.INTRODUCTUIONThe study of welding process control has been dominated by research into methods of in processing sensing of the weld pool geometry. While it has been shown feasible to measure the topside pool geometry using video methods [1,2], the penetration or backside bead width have remained elusive quantities. This is particularly true if a topside sensor location is required.The concept of using weld pool motion as a pool geometry sensing method was proposed by Hardt et al. [3] and later demonstrated by Hardt and Zacksenhouse [5] and Richardson and Renwick [6]. The concept is based on the fluid dynamics of a pool constrained by a solid container and by significant surface tension forces (i.e. a small shallow pool, not a ""pond"" or ""lake""). Such a pool, if subjected to external forces, will exhibit a surface motion is a function of that force, the properties of the fluid, the surface tension, and the shape of the container. Thus, if this motion can be excited and measured, and the relationship to the pool geometry determined, a means of sensing pool shape will exist."

Jan 1, 1986

By K. Itagaki, H. Henao

"The experimental study on the phase equilibrium and distribution of minor elements such as chromium and copper between magnesia saturated FeOx-MgO-SiO2 slag and Fe-Ni alloy were carried out under controlled oxygen partial pressure between 10-6-5 and 10-10 using CO and CO2 mixed gas at 1773 and 1873 K.The effect of slag additives such as lime (CaO/SiO2 molar ratio: 1) and alumina (AlO1.5/SiO2 molar ratio: 0.1) on the distribution behavior of the minor elements was also investigated.The value of distribution ratio for chromium, defined by (%Cr in slag)/[%Cr in alloy], is larger than 70 at the pO2 region conducted in the present study for the MgO saturated FeOx-MgO-SiO2 slag at 1773K. These value are almost 4-order higher then that of nickel though the distribution ratio of copper shows similar values with nickel. Analysis of the data indicates that addition of lime in the slag and the increase of temperature reduce the dissolution of chromium into the slag and the addition of aluminum increases the dissolution of chromium into the slag while reduces the dissolution of copper and nickel.IntroductionChromium. is a minor element in a nickel oxide ore but a Japan major component in the secondary material of stainless steel and is also introduced in the Fe-Ni production process due to dissolving bricks of a furnace. Chromium is a concerned matter for the beneficial utilization and disposition of ·slag because Cr6+ is a harmful element. Considering Fe-Ni as an alloy component in steel making, and the demand of high purity nickel, chromium is an -undesirable element that has to be eliminated into slag prior to the steel making, or the production of high temperature refractory alloys. On · the other ·hand chromium is an element of steel alloy for many applications, thus Fe-Ni containing chromium in minor element is desirable in some stainless steel making."

Jan 1, 2000

By Pura Alfonso, Teresa Escobet, Hernan Anticoi, Eduard Guasch, Josep Oliva, Sarbast A. Hamid

"The liberation modelling of mineral particles using mineral liberation analysis have been used in the past to model comminution and concentration processes. In this work this concept has been taken a little further, using comminution and concentration for applying the mineralogical characteristics of particles. This approach is shown using the image analysis, mineral liberation analysis and the distribution density functions for liberation modelling. The work focused on the effect of comminution on mineral liberation for liberation modelling. To model this, effect the mineral liberation of the particles using distribution density and the cumulative distribution was linked to the image analysis of the ore particles. These properties have been estimated by statistical measures such as the distribution density and liberation grade, which were extracted from MLA data and images analysis, using proper image analysis and techniques based on MATLAB software. A comparison of different tungsten ores of liberated particles, has been introduced and evaluated by estimated results and image analysis.INTRODUCTION The chief economic minerals of tungsten are wolframite [(Fe,Mn) WO4] and scheelite(CaWO4), and approximately two-thirds of the world tungsten reserves consist of scheelite deposits (Lassner and Schubert, 1999). Tungsten has unique properties and is widely used in various industrial high strength and high temperature applications. It occurs coarsely aggregated in low grade ores. Most of tungsten ores, particularly scheelite, wolframite and ferberite, occur in deposits with very low content of WO3 (0.1–2.5%) that is not economically viable to apply directly metallurgical methods to extract tungsten (Martins, 2014). Tungsten is considered as a critical metal by the European Union by the economic importance and also the high supply risk (European Commission, 2014; Chakhmouradian et al., 2015).Currently, scheelite is playing an increasingly important role in tungsten industry because the mineral reserve of wolframite is getting depleted after gradual exploitation and utilization (Min et al., 2016). In mineral processing, the liberation of valuable mineral from the gangue determines the efficiency of subsequent separation processes. The liberation characteristics of an ore are primarily dependent on its texture, the association of mineral in the host matrix of gangue minerals, and to some extent on the grinding process (Zhang and Subasinghe; 2013)."

Jan 1, 2017

By S. D. A. Hannot, H. Knapp

"High pressure grinding rolls (HPGR’s) are an energy efficient solution for comminution of industrial minerals and metal ores. The technology is successfully applied in an expanding field of applications throughout the minerals industry. HPGR’s compress and grind the particle bed in the operating gap between two counter-rotating rolls. The equipment provides a high capacity, low energy alternative for applications with conventional tertiary and quaternary crushing and grinding, with size reduction reaching from 100mm down to 25 microns product. In this process, maintaining a controlled and evenly distributed operating pressure between the rolls is very important. Due to feed segregation, the pressure distribution along the roll’s length can become uneven, resulting in a coarser product. This paper will show that the best approach to compensate and adapt for the uneven pressure is to allow the rolls to skew relative to each other. Coarser products are also caused by an inadequate pressure distribution: the much-discussed edge effect. To minimise the consequence of the edge effect, an optimised ratio for the roll length to diameter will be calculated. Furthermore, the design philosophy behind a cheek plate will be detailed. This cheek plate is used to retain the material between the rolls, reducing the edge effect while still allowing roll skew. Together these design considerations help optimise HPGR’s performance.INTRODUCTION Initially developed for the cement industry during the energy crisis in the 1980’s , high pressure grinding has been an accepted technology for many years. It has been successfully implemented throughout the minerals industry, with applications in base and precious metals, as well as industrial minerals processing. The comminution process relies mainly on size reduction through to compression and inter-particle crushing in a particle bed in the operating gap between two counter-rotating rolls. The equipment typically has a high unit capacity and low energy consumption, and is increasingly used as an alternative to conventional tertiary and quaternary crushing and grinding, in particle size ranges reaching from 100mm down to 25 microns. It can be applied to moist ores and dry material, in open circuit arrangement or in a closed circuit with dry or wet classification (screening, air classification)."

Jan 1, 2019

By S. Schade, G. Möllemann, C. Niestroj

"Mining environments, whether open-pit or underground, pose difficult conditions for any sensor system. However, the ever-increasing need for automation requires the application and use of sensor systems in order to gather relevant information required for process automation. Ultra-Wideband radio (UWB) is a robust technology well-suited for underground applications. These applications include positioning and communication. This paper introduces UWB and presents results from measurement campaigns in harsh environments. Using filtering and sensor fusion precise and robust positioning can be achieved even in confinements of underground mining environments. INTRODUCTION Indoor positioning systems (IPS) are gaining ever more importance. Especially in light of ongoing efforts to reach the goals of what was coined as Industry 4.0 by the German government, the development of IPS is inevitable. According to a recent report about the “Global Indoor Location Market Outlook 2019” a growth from $ 597 million in 2014 to $ 3961.8 million by 2019 is expected [1]. Hence, there is also an economic incentive to pursue this topic. The mining industry is profiting from this development as well, since IPS are the basis for the automation of especially mobile mining equipment. Ideally, indoor positioning systems offer to position the equipment continuously and, what’s more, even in real-time [2]. Different approaches are available for IPS. The difference of these systems lie in terms of accuracy, cost, precision, technology, scalability, robustness and security. [3] At the Institute of Advanced Mining Technologies (AMT) of RWTH Aachen University, research suggests that one of the more auspicious approaches for IPS in the mining sector is the employment of ultra-wideband (UWB) radio technology. Because of this, there has been ongoing research into the best way to introduce UWB technology for the application in underground environments. The research started with an indoor positioning application, which only consisted of the UWB system. In the course of this, different algorithms were developed to enhance the system’s performance for the use in the mining industry. This led to the idea of sensor fusion in which the information of the UWB system are combined with infrastructure-independent technologies like inertial navigation systems (INS) and image-based technologies."

Jan 1, 2017

By Craig H. Olson

"A new ship dock at a Philadelphia area refinery will be capable of docking the largest tanker to travel the Delaware River, the Stena V-MAX, which will induce significant lateral loads. The loads at the dock, a system of mooring dolphins and platforms, will be resisted by over 150 pipe piles, including some 20- and 30-in diameter, reinforced, concrete-filled pipe piles and H-piles. Construction included driving the pipe piles to the required ultimate capacity, flushing the pipe pile casing clean of overburden materials, followed by drilling rock sockets into the underlying Wissahickon Formation. The Wissahickon Formation is a complex subsurface that includes variations in depth to bedrock, rock quality, degree of weathering and the presence of very hard quartzite lenses or inclusions. Because of the problematic subsurface, the designers and client requested extensive pile dynamic analysis (PDA) testing by TRC Engineers (TRC).Before beginning, the contractor requested that TRC perform the WEAP (wave equation analysis program) to evaluate the proposed hammer (APE D30-32 open-end diesel) to drive the piles into the proposed bearing strata while maintaining allowable compression stress levels. The WEAP provided a prediction of blow counts and stresses for various ultimate capacities, and showed that for the HP14x89 piles with a required ultimate capacity of 480 kips, a blow count of at least four blows per in at a stroke of 8.0 ft was necessary.New Approachway RampThe PDA testing began at the new dock approachway ramp, parallel to the existing one. The new structure is a 300-ft-long by 21- ft-wide concrete deck supported on seven bents; each has two 24- ft-diameter steel open-ended pipe piles. Every pipe received an HP 14 x 89 x 80-ft pile that was later driven beyond the pipe pile tip to create a composite pile. The pipe piles were later cleaned of overburden materials and finally filled with concrete and rebar. At each bent, a cap was installed on top of each pair of pipe piles, and then a prefabricated concrete deck was added."

Jan 1, 2008

By Craig H. Olson

"Anew ship dock at a Philadelphia area refinery will be capable of docking the largest tanker to travel the Delaware River, the Stena V-MAX, which will induce significant lateral loads. The loads at the dock, a system of mooring dolphins and platforms, will be resisted by over 150 pipe piles, including some 20- and 30-in diameter, reinforced, concrete-filled pipe piles and H-piles. Construction included driving the pipe piles to the required ultimate capacity, flushing the pipe pile casing clean of overburden materials, followed by drilling rock sockets into the underlying Wissahickon Formation. The Wissahickon Formation is a complex subsurface that includes variations in depth to bedrock, rock quality, degree of weathering and the presence of very hard quartzite lenses or inclusions. Because of the problematic subsurface, the designers and client requested extensive pile dynamic analysis (PDA) testing by TRC Engineers (TRC).Before beginning, the contractor requested that TRC perform the WEAP (wave equation analysis program) to evaluate the proposed hammer (APE D30-32 open-end diesel) to drive the piles into the proposed bearing strata while maintaining allowable compression stress levels. The WEAP provided a prediction of blow counts and stresses for various ultimate capacities, and showed that for the HP14x89 piles with a required ultimate capacity of 480 kips, a blow count of at least four blows per in at a stroke of 8.0 ft was necessary. New Approachway RampThe PDA testing began at the new dock approach way ramp, parallel to the existing one. The new structure is a 300-ft-long by 21- ft-wide concrete deck supported on seven bents; each has two 24- ft-diameter steel open-ended pipe piles. Every pipe received an HP 14 x 89 x 80-ft pile that was later driven beyond the pipe pile tip to create a composite pile. The pipe piles were later cleaned of overburden materials and finally filled with concrete and rebar. At each bent, a cap was installed on top of each pair of pipe piles, and then a prefabricated concrete deck was added."

Jan 1, 2008

By A. Hekmatnejad

"The objective of this work is to validate a methodology for spatially predicting the fracture intensity, defined as the average fracture area per unit volume. First, using the observations from drill holes, the fracture intensity is directly inferred at the support of drill-hole composites based on a Terzaghi correction. Subsequently, the composite values are interpolated to larger blocks. The methodology is tested on sets of simulated fracture networks, in which each fracture consists of a disc with a random diameter, random position and random orientation. For each of these simulated networks, one can calculate the actual fracture intensity within any region of space, based on geometric considerations. A regular sampling mesh is then defined to emulate a set of vertical drill holes and the proposed methodology is applied to predict the fracture intensity, both globally and locally. The actual and predicted fracture intensities are finally compared, showing that predictions are unbiased, insofar as, on average, the prediction error is always close to zero. Also, the error dispersion increases when the support of the prediction decreases, which is consistent with the well-known support effect. In practice, the proposed methodology allows predicting fracture intensity based exclusively on drill-hole information, without the need for simulating fracture networks in space, hence its interest. INTRODUCTION The characterization of fractures in rock masses is an important part in the evaluation of mechanical and hydraulic properties of rocks. Fractures have a large impact in disciplines such as reservoir engineering, safety of underground storage of CO2 or of nuclear waste, assessment of high-enthalpy geothermal installations, safety of mining exploitations, efficiency of in-situ leaching operations or of extraction by block-caving. As a rock mass property, fractures must be characterized in the three-dimensional space, whereas observations are limited to 1D (drill holes) and 2D (outcrops, drift walls), moreover very often to rather short stations, so that the available data are subject to geometric bias, truncation and censoring. Fracture characteristics includes the number of fracture sets and, for each set, the number, orientation, spacing, location, shape and size of the fractures must be inferred from data sampling. Some important parameters that are considered nearly in all models are fracture intensity and fracture size."

Jan 1, 2016

By Karen C. Armfield, Gisele R. Passalacqua, Joanna Smith

New York City is an urban environment with a history spanning over 200 years. The coastline of New York has changed over the years. In the East River, old bulkhead and remnant of relieving platforms together with variable bedrock elevations pose challenges in the design and construction of deep foundations. This paper presents a Case History of high capacity deep foundations along the Franklin D. Roosevelt (FDR) Drive on the Upper East Side in New York City. The project consists of a ramp that overpasses the FDR Drive allowing heavy trucks to access the Marine Transfer Station (MTS) facility built over the East River. Large diameter drilled shafts and mini-piles socketed to bedrock were designed and constructed. Remnant of old bulkhead was encountered at the site and a Ground Penetrating Radar (GPR) investigation was completed during the subsurface investigation phase of the design. This paper discusses details of the subsurface investigation program and design methodology of the high capacity drilled shafts and mini-piles. It also describes construction methods and results of Osterberg Load tests documenting the field values of skin friction through the rock socket. Other construction challenges include construction and drilling rock sockets for drilled shafts over sloping bedrock. 1. INTRODUCTION New York City is a renowned urban city that always calls for the most delicate, yet complex, and robust superstructures and most importantly substructure designs. The historic preservation of this large 200 years old city of 319 square miles is ever changing. Shorelines are often extended to accommodate new infrastructure and very often many miscellaneous structures are discovered below the ground surface. The East 91st Street Ramp was constructed to provide access to the East 91st Street Marine Transfer Station over FDR Drive and York Avenue. Another alternative ramp will be relocated to the South Bound (SD) of the FDR Drive at 92nd Street. A subsurface exploration program was completed in accordance with the New York City Department of Design and Construction (NYCDDC) general requirements, Section 4.5, to perform subsurface investigation along the FDR Drive in Manhattan, New York.

Jan 1, 2019

By James W. Neill

Discussion of the paper of H. 0. Hofman, presented at the Canal Zone meeting, November, 1910, and printed in Bulletin No. 42, June, 1910, pp. 473 to 497. JAMES W. NEILL, Pasadena, Cal. (communication to the Secretary *) :-Professor Hofman's paper brings the art up to . date. As I was one of the pioneers in this business, I beg to give the following incomplete data regarding my efforts in this line. In the year 1883, while I was in charge of the smelting-operations at Mine La Motte, Mo., there was at the concentrator an unusually large production of a middle product, locally called "iron," which carried considerable values in nickel and cobalt, and which it was desirable, for this reason, to treat by itself. The works could not spare a furnace for the purpose; and to handle this product I improvised a "roast-hearth " from an old " lead-hearth." This was a small cast-iron furnace of the usual construction, about 2 by 4 ft. in dimensions, with a hollow cast-iron back, through which the wind circulated before entering the tuyeres. I had a cast-iron grate made to fit this hearth, and placed it flush with the lip, or apron, and above the tuyeres. On this grate, which had round holes about 0.25 in. in diameter, and a total surface of about 20 by 40 in., I roasted the nickeliferous pyrite product; starting the fire with kindling, then adding charcoal, and then gradually feeding the sulphides with a shovel, so as to cover the fire, choke down blow-holes, and get an even bed. Blast at a pressure of 3 or 4 oz. was supplied by a fail-blower. When a cake of roasted material had formed, it was removed with a steel bar, or fork, to the lip of the furnace, and thence into a wheel-barrow.. The fine material which had remained unmelted, but very hot, on top of the cake would promptly ignite when the cake was broken up and removed. The fire would then be covered with fresh material and * Received Aug. 29, 1910.

Apr 1, 1911

By N. Duru

"Gravity concentration is still a challenging area in the mineral industry. This is mainly because of the fine size valuable mineral losses to the tailings during its application. But the recent developments in centrifugal separation methods and their mutual application with conventional separation techniques has increased mineral recoveries. In this paper, field application of conventional gravity separation methods with the combination of 2” diameter hydrocyclone cluster unit and a multi gravity separator (MGS) was discussed. Additionally, particle size distribution and chromite content of the plant streams is presented and initial laboratory test results were compared with the actual plant data throughout the paper. As expected, field data showed derivations from the laboratory tests but the combination of MGS and conventional gravity separation techniques resulted in gravity separation of -0.1 mm chromite particles. INTRODUCTION The purpose of this mineral processing plant project was to investigate the possibility of upgrading chromite ore from 12% to 48% Cr2O3 and having final tailings assay as 2% Cr2O3. For this reason, initially a set of laboratory gravity separation studies were conducted to evaluate the performance of combination of 2” diameter hydrocyclone cluster and multigravity separator. After obtaining successful results from the laboratory work, a feasibility study was initiated. Economical results of the feasibility study showed that an achievable high net present and return on investment values. Following the investment decision; engineering, equipment procurement, construction of the processing plant was completed in eighteen months. This paper focuses on the initial laboratory test work results, operational data of the 2” diameter hydrocyclones and MGS units; resulted chromite recoveries. Processed ore has the chromite associated with serpentine and olivine minerals. The chromite particles are generally in round shapes with sizes between 50 µm to 1600 µm and average size of 450 µm. The microscope images of the chromite and associated formations are presented on Figure 1.Chromite is formed in mixture with iron oxides, with varying amounts of magnesium, aluminum. The average chemical composition of the representative drill core samples of the ore deposit is given on Table 1."

Jan 1, 2017

By J. E. Gill, A. R. Byers

"The property of Sladen Malartic Mines, Limited, is in the northern half of Fourniere township, Abitibi county, Quebec. The group is large, but the part so far found to be of economic interest is a strip 3,200 feet long between the Canadian Malartic property to the west and the East Malartic and National Malartic properties to the east ( Fig. 1).The original claims were staked in 1923 and 1924 by St. B. Sladen and H. S. Kennedy because gold was known to occur on claims nearby. In 1928, detailed mapping of the Malartic Gold Mines property (now Canadian Malartic) showed the presence of an east-west gold-bearing zone traceable almost to the Sladen boundary. During the winter of 1929, a hand-driven drill was used to secure short sections of core through casing pipe sunk to bed-rock. This proved the existence of the main Sladen ore zone, but it was not until the price of gold was increased, in 1934, that serious work was attempted.Underground work was started in 1935 and milling in January, 1938. To the end of 1945, 168,882 oz. of gold were recovered from 1,641,974 tons of ore, an average of 0.103 oz. a ton.GEOLOGYThe bed-rock underlying' the Sladen Malartic property consists mainly of Precambrian greywacke and volcanics that appear to form a conformable series with a general northwest strike and vertical to steep northerly dip. Except where disturbed locally by drag folds or faults, tops face north. Intrusive rocks that range in composition from diorite to granite cut the sediments and volcanics. The basic types, generally quartz diorite and diorite, form dykes or sills in the volcanic rocks. The more acidic types, mainly quartz syenite and related porphyries, intrude the volcanics and the sediments in the form of dykes, sills, and larger, stock-like bodies.The orebodies are parts of slightly shattered or brecciated zones, mainly in greywacke, but partly in syenite, diorite, and volcanics, that have been more or less replaced by fine-grained quartz, pyrite, and minor amounts of sphalerite, galena, sylvanite, petzite, and gold."

Jan 1, 1954

By Roberto Pena, Cristhian Morales, Darwin Morales, Veronica Cambiaso

"This article makes evident the shortcomings of the current operation of oxygen pipes as well as the damages they cause and why they cause them. When focusing on the causes and effects of these drawbacks, it was possible to develop a new family of thermal lances that could pierce a taphole with the precision of a drill but with the capacity to complete the whole operation. Although efforts have been made to replace oxygen pipes since they are annoying, dangerous and inefficient, nobody had worked to improve the way the traditional oxygen pipe taps/perforates the furnaces and reactors tapholes. In fact, developments made in drills and robotic arms, have failed to replace the oxygen pipe, which despite their negative side effects have been used for more than a century. Observation and theory were key to radically transform this humble tool into a dependable and efficient support in the operation. A good news that it is worthwhile to share for the benefit of all of us, passionate about the world of pyro metallurgy.INTRODUCTION Normally, reports and papers prepared for conventions, symposia or other technical events related to metallurgy aim to relevant topics in the operational field, probably because in them lay the scale economies every company pursues. We intend to give relevance to a matter normally disregarded in operations, but that unmistakably vital: if the furnace or reactor cannot be bled, the pyrometallurgical process will not be completed. Besides, if the tapping task is difficult or is long delayed, the availability of the furnace will be reduced. Consequently, there will be a waste of energy and workers will be exposed to dangerous levels of radiation as well as to work overload and physical injuries Apart from these basic effects, in tapping operations where oxygen pipes are used, we can see serious damages in the smelting furnace, especially in the taphole components such as refractory bricks, taphole jackets and water cooled plates. This paper intends to show that taking care of the tapping task can significantly upgrade not only to the tapping operation itself, but also the whole plant productivity."

Jan 1, 2017

By A. Hasselbring

Sub-Level stoping was used in this country at least as early as 1912, at the Magpie mine in Michipicoten. The fundamental principles of the system are the same wherever it is used, but modifications have been adopted in the Michigan iron mines and in several Canadian mines. It is a system whereby a suitable body of ore may be developed quickly and worked cheaply, with a low initial expense, and by miners of quite ordinary ability. The basic method, described in the following pages, may be modified to meet conditions where one or more factors are not in accord with normal sub-level stoping requirements. In suitable ground, sub-level stoping is probably the most satisfactory method yet devised for underground hard-rock mining. It is so simple, straightforward, and safe that no special training of a crew is necessary. Any miner capable of drifting and raising can carry on the work necessary for sub-level stoping after the shaft has been sunk. The method is suitable, however, only for reasonably wide ore-bodies, the minimum width of ore to which it can be economically applied being somewhere in the neighbour-hood of thirty feet. The development programme is simple. Assuming, for purposes of illuslustration, an ideal ore-body, two thousand feet long, dipping nearly vertical, and varying in width from forty to a hundred feet, this programme would be as follows. The shaft should be sunk on the footwall side about sixty feet outside of the ore-body and near its centre. Levels are then established at suitable intervals, usually 125 feet. On each level, a cross-cut is run to the ore-body, and there a main-haulage drift is driven in either direction to the end of the ore. Cross-cuts are then run at 25-foot intervals, so that ore-chutes can be spaced about 25 feet centre to centre each way. It is not necessary that these cross-cuts be extended to the walls of the ore-body, if the position of the walls is known; they are extended just far enough to make room for the correct location of the chutes.

Jan 1, 1934

By K. Trapani

"The study undertaken aims to investigate an ice stope heating and cooling system for its potential to be implemented in sub-arctic mines, as a low carbon alternative to conventional natural gas and refrigeration chiller systems. Its performance was simulated for a years’ worth of data, taking into consideration hourly temperature data. Results showed that to supply the required heating and cooling loads, the ice stope system had to supplement its heating with natural heating. The techno-economic performance of this system was compared to that of a conventional heating and cooling system in a mine, with the ice stope thermal storage system hawing the lowest annuitized cost and significantly lower carbon emissions.INTRODUCTIONConventional heating and cooling, in a mine is implemented using natural gas heaters and chiller refrigeration systems respectively. This results in a significant portion of energy consumption in underground mines attributable to ventilation (De Souza, 2015), including the conditioning of the air to ensure that temperatures do not exceed work comfort standards (ACGIH, 2011). Especially at depth where heat could become a significant issue. An ice stope thermal storage, using ice as the storage medium is being proposed as an alternative to provide the heating and cooling—with the ice creation resulting in heating and the ice melting providing the cooling required. A techno-economic investigation of the two systems is undertaken to identify the capital and operating costs for the two systems, and to assess the ice stope’s potential to be considered a low cost and carbon solution for heating and cooling of mines in sub-arctic climates.NATURAL STORAGE SYSTEM – CONCEPT DEVELOPMENTThe concept for the natural storage system is developed from the ice stope at Frood-Stobie Mine, ON, Canada (Stachulak, 1991). The ice stope was developed for mine air heating, with the heating occurring by spraying warm return service water onto the cold intake air—resulting in the air temperature increasing and ice being created in the stope. In summer this ice was melted by passing warm air on top of it, resulting in slight cooling of the air but no significant temperature difference which could allow effective cooling. A schematic of the Frood-Stobie Mine ice stope is provided in Figure 1."

Jan 1, 2019