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By Benjamin Cebrián, María Gil, David Flores

In many occasions during the Mining operation life, blasting engineers find different and controversial results of fragmentation, dilution or wall control for the same geotechnical domain and blast design (pattern and explosive charge). Most of the times, the difference between same blast designs is not measured, not controlled. Once a blast designed is defined, the most important part of the process after that is the implementation of every step of the blast on site. Almost nobody is measuring it, controlling it, but just controlling implementation is possible to relate blast design with results in a consistent way, to optimize the full process of D&B. Controlling implementation not only per event but also to check and change trends and decision-making is paramount for optimization and saving millions of extra costs every year. The lack of resources and the hardness to manage all the info created every day in a blast make this process very tough and difficult to maintain in long term. The use of new technologies on site and software that allows a best, more consistent and continuous control of blast implementation have been proved to be the key for optimizations and cost saving. This document shows the evolution of drilling and blast digitization process, savings and trends in a mine, using new technologies that creates business opportunities and general improvement of D&B process.

By Soner Top

In this study, a process to separate manganese and iron from manganiferous iron ores by reductive acid leaching followed by magnetic separation was conceived and experimentally tested. In the leaching process, sulfuric acid was used as lixiviant and oxalic acid was used as reductant. The experimental results showed that the manganese and iron separation was optimum when the concentration of the sulfuric acid and oxalic acid were 0.75 M and 30 g/L, respectively, at a temperature of 80 °C, a solid/ liquid ratio of 67 g/L, stirring speed of 400 rpm, and leaching duration of 60 min. Under this condition, 90.49% and 6.78% of Mn and Fe were dissolved, respectively, from the ore sample with a size fraction of − 106 μm. It was determined that the leaching of manganese from the ores was a second-order reaction with an activation energy (Ea) of 53.38 kJ/mol. The leaching residues obtained under the optimum condition were subjected to high-intensity wet magnetic separation tests to recover the remaining iron content. This separation process produced a concentrate containing 56.20% Fe and 1.79% Mn with iron and manganese recoveries of 56.83% and 66.73%, respectively. A magnetic separation test from an unleached ore sample was also carried out as a benchmark. To the best of our knowledge, this is the first time that a magnetic separation process was used to a residue obtained from reductive acid leaching of manganiferous iron ores to recover iron.

By Patrice Favreau, R. F. Ph. D. Professor Emeritus Favreau

After Nobel invented dynamite, blasts were carried out by trial and error, without the use of equations based on the fundamental principles of Chemistry and Physics, although everyone accepted that shock waves were involved; but no equations were available to calculate their intensity. Around 1950 however, M.A. Cook proposed a procedure to calculate the thermochemistry of an explosive, and thus evaluate theenergy released during the explosion of a fully confined explosive. Some blasters then began to use theEnergy Factor; the latter, however, does not subdivide the energy into its three kinds of activities necessaryfor a successful blast, as demonstrated in 1968 by reference 2, namely i) the shock wave which weakensthe rock; ii) the stress field SS which fully fragments the rock; and iii) the release of the stress SS whichcauses the fully fragmented rock to burst out with the velocity necessary to move the rock into the muckpile. The article explains that the way to achieve a successful blast is by insuring that the explosive energy divides properly into the weakening action of the shock wave which is necessary to prevent large collar blocks and toe, and into adequate stress field intensity SS which is necessary to obtain good fragmentation size distribution at the crusher, as well as adequate burst out rock movement to achieve easy mucking.

By F. Twyman, D. M. Smith

Those chemists (they are still greatly in the minority) who use the spectroscope, use it very often, and find it almost indispensable. As a means of detecting minute quantities of the metals it is unrivalled. A metal can be readily distinguished in the presence of any other element, compound, or mixture without the necessity of separation. The qualitative analysis of the metallic constituents of a substance, which the spectroscope gives so easily, is a sure basis for planning a chemical analysis. As the determination of each element proceeds the purity of precipitates may be checked as often as desired. If, possessing these advantages, the spectroscope has been neglected in general chemistry, it is not surprising that it was neglected in metallurgical chemistry; for many of the impurities which are of industrial interest, even when they are present in a metal or alloy in small quantities, are not then always easily detected by the examination of their visible spectrum. The history of the development of the art has been given in Bureau of Standards 19cientific Paper No. 444. The Development of Analysis by Spectrogbaphy Fig. 1 shows, by means of photographs taken with a quartz spectro-graph, what a valuable region of the spectrum is excluded if one has a visual instrument only. Wave length 4023 is about the end of the visible spectrum, the region from 3800 to 1854 being invisible. It is easy to understand then how it is that the vigorous resuscitation of spectrum analysis which has commenced in the last few years has been associated with the use of the quartz spectrograph; notwithstanding that the most useful instrument for the general inorganic chemist to have at his elbow, after the balance, is a good visual spectrometer.(1) 1 The revival of spectrum analysis is to be attributed chiefly to the work of W. N. Hartley with his co-workers, and to A. de Gramont. Hartley,

By Rohrbach

Crosshole Sonic Logging (CSL) testing is commonly used to verify the integrity, quality and ultimately the acceptability of the concrete in structural elements such as drilled shaft foundations, secant pile cutoff walls, and secant/tangent pile earth retention structures. Besides concrete quality, many factors can impact CSL test results (e.g. laitance, air temperature, access tube spacing, access tube debonding, etc.). Effective use of CSL testing requires fully informed qualified practitioners capable of distinguishing between abnormal readings unrelated to deficiencies in the drilled shaft concrete and similar readings indicating the presence or possible presence of drilled shaft defects. Based on data and experience gathered from CSL testing of thousands of drilled shafts across North America, this paper discusses such factors and other information useful when evaluating CSL test results, and provides practical recommendations intended to reduce the potential for incorrect test data interpretation. The CSL testing industry is lacking in a clear, universally accepted guideline for the interpretation of CSL data and acceptance criteria of these concrete elements. This paper proposes terminology and a streamlined process for use when atypical results are obtained. The proposed terminology and method are intended to simplify and expedite the submittal review and approval process. Because construction activities for these elements are often on the project?s critical path, the benefits obtained in terms of project savings and reducing costly delays are undoubtedly valuable.

By Anthony Harding

In a world of technology and electronic communication, it is easy to forget what engineers do best with a problem: sitting around a table, exchanging views and ideas with sketches and respecting everyone?s view. This was the approach adopted in the project to arrive at a solution for the cross passage opening sup-port for the Seattle University Link Extension. Schedule and space constraints usually impede concurrent cross passage excavation and tunnel boring machine (TBM) operation. And where the space is constrained, opening support solutions that maximize available cross sections are of great benefit. While there are a number of solutions that minimize space, some of these solutions can require expensive steelwork and extensive drilling and fixing. However, following a detailed round-the-table discussion of the options and constraints, it was identified that a shotcrete shell would not only limit obstruction of the space during installation, but also permit easy installation, particularly around services, and avoid costly steelwork and drilling and fixing.

By J. P. Timmons, J. H. Moran, G. K. Miller, M. A. Coufleau

A prototype equipment has been designed and built for the digital recording of well logs on magnetic tape at the same time that the regular film recording is made. The format of the digital tape produced is such that it can be used directly at the input of the ZBM 704, 7090 or other models of ZBM computers which accept digital magnetic tape. This apparatus has been used for the experimental field recording of dipmeter tape logs which were subsequently computed by means of an ZBM 704 or 7090. In this paper the equipment and the digital tape are described briefly, and their application to the computer-interpretation of dipmeter data is discussed. A principal element in the interpretation of the dipmeter log is the correlation of the three microresirtivity dipmeter curves to determine the depth displacements between them. Several correlation methods for computer use are considered, with particular attention to their sensitivity to error and their consumption of computer time. The tape data were used to compute information content of the dipmeter microresistivity curves in terms of their frequency spectra. The results show that the sampling rate used in recording the digital information is quite adequate and illustrate a use of the digital tape in evaluating the characteristics of new tools. Some examples of field results are shown. It can be foreseen that, when digital tape recording becomes available for general field use, a whole new realm of possibilities will be opened up for the processing of other well logs through computations, which hitherto were not feasible because they were too laborious and time-con.sunzing. INTRODUCTION The last few years have seen a revolution in the design and production of data-processing equipment. Stored-pro-gram digital computers have progressed from a research curiosity to the basis of a major industry. There are now hundreds of such machines in daily use in the United States. With the acceptance of a technique that was, in fact, already clearly described by John von Neumann in 1945, the last decade has seen great strides in the development'of components, reliability, programming systems and, most spectacularly, in the sheer number of machines built and in use. In 1957 there were enough digital computers available to the oil industry to justify the suggestion that it would be worthwhile to investigate the possibility of using these machines in processing well log data.' The first result of this investigation was the appearance of what may be referred to as the input-output bottleneck. Well logs are customarily recorded on film. To get these data into a machine required then (and still does): a time-consuming semi-automatic reading of the film; conversion of the log data to digital form; and recording these digital data in some medium acceptable for computer input, such as cards, magnetic tape, or punched paper tape. However, the recording, reading, and re-recording could only result in deterioration of the data. Therefore, it was concluded that the fist step should be the development of a new, more direct recording technique supplemental to the film recording, which would provide easy access to the digital computer. There are many solutions to the problem of recording log data in an easily recoverable form. After careful consideration it was decided to adopt the boldest solution which, it was felt, was also the most elegant. It was decided to record well logs directly, in the field, on magnetic tape in such a way that this tape could be used without further modification as an input to the IBM 704 or 7090 computer. To realize practical field recording of magnetic tape logs, it became necessary to develop in a rather small package, an analog-to-digital converter, a tape recorder, and the necessary multiplexing and control circuits to allow the simultaneous recording of a multiplicity of logging signals. The magnetic tape recording was to be made simultaneously with the conventional logging operation in such a way as not to interfere with it. Along with the development of hardware, it was necessary to begin development of interpretation techniques and machine programs that would exploit the power of the digital computer. Here, again, there is a long list of possible applications. After much consideration it was decided to concentrate on the interpretation of the dipmeter log as a first application. It is the object of this paper to describe in some detail the developments sketched in the last three paragraphs.

By François Larouche

Since their commercialization in the early 1990s, lithium-ion batteries (LIBs) have become ubiquitous for powering a myriad of portable electronics. Their usage now extends to the automotive industry and stationary energy storage market. With an average life of 6.2 years and the strong demand, the volume of spent LIBs has increased exponentially, making recycling mandatory. Currently, recycling/ recovery of spent LIBs is limited in comparison to all other types of batteries. The current processes focus mainly on the recovery of the most valuable metals such as cobalt and nickel, leaving lithium and phosphate in a low value end-product. It is necessary that new advanced recycling technologies are developed for the recovery of spent LIBs both from an economic and environmental perspective. In this paper, the current R&D status of LIBs recycling is reviewed with the emphasis placed on hydrometallurgical processing opportunities for Li-ion and Li-solid state batteries.

By Stephen C. Tadolini, Dennis R. Dolinar

The risk of injury caused by minor roof falls continues to increase in underground mining. Most ground control injuries result from small rock falls that occur in a supported area, but do not involve the failure of the support system. In the roof, these are the "skin failures" that occur between previously installed primary or secondary bolting systems. To minimize skin failures and the associated accidents, several devices were designed and tested in the laboratory to maximize stiffness, minimize material thickness and weight, and ease material storage and handling on roof bolting machines. The goal of this project was to design and evaluate devices that can be installed with traditional primary or secondary roof supports, and that are easy to handle/install under temporary or previously supported roof.

By Steve Skelhorn

Over the recent years, major advances have been made in design of precast concrete segmental tunnel liner. Starting from basic, parallel sided rings, we now have state of the art, universal rings incorporating custom tapers to suit individual requirements. At planning stage, the ring diameter is normally fixed and the ring geometry is one of the first items to be assessed. Obvious factors such as TBM layout and curve radius can constrain geometry; however, there others factors that should be considered in order to optimize production. This paper takes a look at the history of the segmental rings and criteria for ring selection, including: general ring geometry;; individual segment geometry; ring taper, and ring width. This paper also explores optimization of ring with a focus on constructability.

By Jan Steinhoff

The design options of a gravity separator are still limited and rely on the study of settling behavior. A methodology will be presented where an experimentally given inlet droplet size distribution (DSD) is the basis for the calculation of the dispersion layer in a gravity separator. A pilot-scale continuous gravity separator is presented and CFD (computational fluid dynamic) results are validated. A transmitted light measurement technique for the determination of the DSD is presented up to a holdup of 15% dispersed phase. The resulting DSD was in the range of 20–2000 μm depending on flow rate and phase ratio. Furthermore, correlations of the real DSD with the settling behavior of the dispersion in a settling cell are discussed. The new approach to the description of gravity separators will be presented and the applied CFD methods showed good results with the system water/paraffin.

By Christoph Zschiesche

Managing complex material streams within a lead smelting/reduction process has a long history at Aurubis. After modernization of the secondary lead smelter in 1991, Aurubis operates an electric furnace and a Peirce Smith converter to process complex secondary materials. This process links the copper and the lead metallurgy allowing Aurubis to properly combine primary and secondary process lines to optimize the processing of complex raw materials and smelter intermediates. However, combination of copper and lead metallurgy processing requires a continuous evaluation as raw material quality and composition varies. This paper describes Aurubis lead smelter processing and provides some fundamental considerations to optimize the lead processing, in particular with aspects related to speiss formation

By T. Egleston

During the last winter we have been actively engaged in the School of Mines in search for boracic acid. This has been owing to the fact that Mr. M. W. Iles, assistant in the qualitative laboratory, has discovered a test for that substance which makes its discovery exceedingly simple instead of being, as previously, very difficult. It consists in powdering the mineral, calcining it, then moistening it with sulphuric acid, and heating on a platinum wire until the sulphuric acid is expelled. It is then moistened with glycerin and made to take fire. If boracic acid is present it infallibly gives a green flame. It is not at all surprising, under such circumstances, the test being so easy, that boracic acid has been found by the students in a great many cases where its presence was not previously suspected, and in some where its detection was previously too difficult to warrant looking for it. We were not prepared, however, for its discovery in Lake Superior iron ores, and were disposed at first to think that a mistake had been made. After, however, it had been frequently reported in these ores it was considered worth while

By B. P. Spigarelli

To meet the growing need for CO2 capture and storage technology, Michigan Technological University is researching CO2 capture and storage using carbonate solutions. The objective of the present study was to increase the absorption rate of CO2 into the carbonate solution without reducing the absorption capacity of the solution. This approach used a polypropylene glycol methyl ether (PPGME) as a surfactant to chemically alter the gas bubble size. Experiments were conducted to study the absorption rate of CO2 at varying surfactant concentrations of 0, 0.12, 0.24, 0.36 and 0.48 g/L. Results showed that as the concentration of surfactant increased in solution, the absorption rate also increased. The CO2 absorption rate increased from 3.45 mmol/min CO2 at 0 g/L PPGME to 3.92 mmol/min CO2 at 0.48 g/L PPGME. This amounted to a 14% increase in the CO2 absorption rate with no decrease in absorption capacity of the solution.

By John Marsden

Despite the recent pullback in metal and mineral prices, and the associated market adjustments, the mining industry is still facing a serious issue with the declining availability of graduate expertise. This is due to a combination of an aging workforce, retirements and retrenchments, coupled with a lack of suitably qualified graduates entering the workforce. The issue has certainly improved since 2004 when the industry picked up the rates of hiring graduate engineers and mining/mineral school enrollments picked up in response. This hiring effort has helped to cover the ?gap? years from about 1985-2000, when industry demand for graduates was particularly poor. However, the recent market pullback is likely to set back this progress, as recruitment and hiring wavers as a result of cost cutting measures and economic uncertainty. A key issue for the mining industry is how to ensure the survival and growth of relevant ?core? degree programs. Such programs include mining, metallurgical, mineral processing and geological engineering. The mining industry needs a healthy, high-level education program to ensure an adequate supply of appropriately qualified graduates for the mining industry. Two-thirds of the professionals entering the minerals industry who graduated within the past 40 years graduated prior to 1985. Since 1985, we have been living off the legacy of graduation classes from the mid-1970s and early 1980s. It is estimated that we have been producing graduates at approximately 40 to 50 percent of the sustaining rate since about 1985. Further growth in the domestic industry would increase graduate requirements significantly, and the export of U.S.-graduates to other parts of the world (as is currently occurring) also impacts the total graduate requirements.

By R. V. Higgins, A. J. Leighton

Interest by petroleum engineers in the flow of three phases—oil, gas and water—in irregularly bounded porous media lies mostly in the performance calculation of water floods of reservoirs that have been partially depleted as the result of expansion of much of the originally dissolved gas. The authors present a method to forecast three-phase flow in complex geometry and explain the details by the use of a specific example of a five-spot water flood of a partially depleted stratified reservoir. In this example, the fluid and rock properties of a field given by Prats, et al,' were used. The computed results fit the field performance more accurately than Prats, et al, and Slider.' The time required for the high-speed digital computer to make the calculations, including the contributions from the different layered zones, is about one minute. INTRODUCTION The declining rate of discoveries of new oil fields in the United States makes the recovery of more oil from known reservoirs more attractive than previously. Water flooding has an excellent proved background for recovering additional oil economically. Accordingly, the main interest of this paper is in this type of recovery. In petroleum engineering studies, commercial interest in three-phase flow is mostly in the water flooding of reservoirs in which the oil has been partially produced by the expansion of dissolved gas. When water is pumped into these reservoirs, three-phase flow takes place. Although this paper is concerned with these conditions, the principles involved could be used for other conditions when and where they come to the fore. Many investigators have made contributions to non-empirical forecast methods using basic scientific engineering principles. Several of these used the oil in place at the start of the water flood and the oil remaining after a large quantity of water has passed through a core for key values in their calculations. Recently, Prats, et al,' and Slider have reduced assumptions by adding the third phase—gas—in their forecasting methods. Slider uses the mobilities in the immediate vicinity of inlet and outlet wells as an aid to simulate the resistance effect in the five-spat pattern of the flow of oil, gas and water. Prats, et al. minimize assumptions by using previously determined laboratory data for determining sweep efficiency in the five-spot pattern. In neither of these papers is the saturation profile continuously affected by permeability-saturation curves. Sheldon and Dougherty- recently described a method that employs continuously changing saturation profiles using permeability curves, has a minimum of assumptions and needs no prior sweep efficiency. The Higgins-Leighton method, described in this paper, has all of these features; however, many of the techniques are different from those of Sheldon and Dougherty. The Higgins-Leighton method, tested in May, 1961, is direct and easy to apply and requires very little computer time to calculate a forecast. The short computer time is especially helpful in the study of a reservoir containing many layers of different relative permeabilities. In the Higgins-Leighton method, the individual pressures do not have to be calculated, as the resistance to flow in each cell in the flow pattern is readily determined without the use of any iterative techniques. The saturation and permeability distributions are readily determined. These data and the shape factor, which is measured only once from the potentiometric model when mobility ratio is one, determine the resistance to flow in each cell. THEORY The authors showed in a previous paper4 that, as an aid to calculating performance, the reservoir can be divided into channels using the streamlines of a potentiometric model as a guide. See Fig. 1. This procedure also was used in this paper. The authors also showed that, by treating conduits as approximately one-dimensional and neglecting pressure gradients transverse to the main flow, the Buckley-Leverett equation may be expressed as The principles expressed by this equation are employed extensively in the three-phase flow, as they were in two-phase flow. In the three-phase flow, the channels (the size and shape of which are taken from a potentiometric model)

By Broggi Andrea

Condensates produced by SiO(g) and CO(g) have a crucial importance in silicon production. Condensation will follow the reactions 3 SiOðgÞ+COðgÞ→ 2 SiO2 + SiC and 2 SiO ðgÞ→Si+SiO2. Solid compounds generated during silicon production contain Si, SiO2 and SiC in different microstructures and amounts. In industrial systems, condensates limit the SiO(g) escape to the off-gas system. On the other hand, they can block the gas flowing from the high temperature zone, hence the necessity of studying an optimized condensation process. This review discusses SiO(g) condensation and its interaction with CO(g). The report gives an overview of the condensates found both at laboratory and at industrial scale. The two main compounds are the Si–SiO2 and the SiOx–SiC mixtures. The hypothesis on the mechanism of formation of SiC–SiOx condensates is presented through a wide selection of performed works. The advantages and disadvantages of the former experimental procedures are discussed.

By James Humphrey

There is a natural resistance to change in any form. When it comes to implementing a game-changing technology like autonomous haulage on an operating mine site, the resistance can at times appear insurmountable. Whether based on real information or misguided preconceptions, it?s essential that we don?t underestimate the effort it will take to overcome this resistance, while clearly recognizing when it?s worth the effort. These realizations did not happen overnight for sites where autonomous haulage has been implemented. Nor did they happen overnight for manufacturers of autonomous mining equipment. Caterpillar, for example, began building toward autonomy more than 30 years ago and had a truck operating in the mid-1990s. Lessons learned during those early years led to the realization that there was much more to be learned ? not just about the machines themselves, but about the systems and knowledge that must be in place for a successful implementation. Working closely with customers, initiating real-life demonstrations on mine sites, having discussions with regulatory agencies and other stakeholders ? these and many other activities were necessary before autonomy could be fully and successfully launched. After decades of effort, Caterpillar?s first official commercial autonomous mine site went to work in 2011 in Farmington, NM.

By L. F. Elkins

Water coming into wells with bottom water present in the Fosterton field, when their oil recovery was only 0.1 to 1.5 per cent of oil in place below the lowest perforation, confirms lack of shale barriers to vertical flow which also are not apparent in cores and electric logy. Low contrast of vertical and horizontal permeability, high mobility ratio betweerz oil and water zone and pos.rible rate effects due to gravity Combine to prevent easy analysis of water invasion pattern and efficiency by analogy or intuition. Theoretical analysis of performance including these factors using a new direct nurnerical .solution of potential distribution in a network led to unanticapted indications that water would under-run the entire oil reservoir with low volumetric coverage if supplied through natural influx or peripheral water injecfion below the oil-water contact. An unusual pattern of water injection is to he adopted in this recently unitized pool to provide more uniform water flooding in that two-thirds of the oil reservoir not underlain by bottom wafer. INTRODUCTION The Fosterton field, Southwestern Saskatchewan, Canada, was discovered in Jan., 1952. It produces at a depth of 3,100 ft from a pinch-out of the Roseray sand at the Lower Cretaceous-Jurassic unconformity. The field, covering 2,500 acres, contains 54 wells on 40-acre spacing. Development was essentially complete in June, 1954, but significant production did not start until May, 1955, when a pipeline outlet became available. Within one year rapid in- creases in gas-oil ratio and early encroachment of water created operating problems in the down-structure eastern half of the field and raised serious questions about reservoir performance and ultimate recovery. This paper describes the unusual behavior of water encroachment—on both well and reservoir bases—and the analyses made to interpret it. The field was unitized July 1, 1958, for water flooding. A somewhat unconventional

By Weng Fu

In this study, Resin-in-Pulp (RIP) technology is used to separate Pb from a chalcopyrite slurry. Solvent-impregnated resin, Lewatit® VP OC 1026, which contains di(2-ethylhexyl) phosphoric acid (D2EHPA) in a macroporous polystyrene matrix was used, as the functional group exhibits selectivity for Pb over Cu. Adsorption pH, kinetics, as well as resin and CuSO4 concentrations were investigated. The results show that the kinetics of Pb and Cu loading are fast, reaching the adsorption equilibrium within 30 min. The equilibrium pH of 2 was chosen as optimum for operation in order to achieve a high Pb extraction rate and extent as well as selectivity for Pb over Cu. High Cu(II) concentration in solution results in Pb(II) requiring a larger amount of resin for the same degree of extraction. Regeneration and reuse tests show that the loss of adsorption capacity happens in the 1st and 2nd cycles and then the adsorption capacity stabilises for the 3rd cycle.