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For the past 12 years, the Universities of Stellenbosch and Cape Town have hosted an annual symposium to discuss research topics in Minerals Processing. Since 1987, this meeting has been held under the auspices of the Western Cape Branch of the South African Institute of Mining and Metallurgy, and has enjoyed much national and international support. In 1993, in place of the usual Symposium, the Branch and Universities collaborated with CSM Associates Ltd and Minerals Engineering Journal is organizing the international Minerals Engineering '93 Conference in Cape Town.

Jan 1, 1993

By T. Watanabe, T. Fujiwara, S-Wan Song, Y. Nakagawa, R. Teranishi, M. Yoshimura

"We have tried a new method to fabricate cobalt oxide films onto porous films directly by an electrodeposition method at low temperature. The porous substrate films (membrane-filters and paper) were placed between a LiOH solution and a CoSO4 solution and treated under electricalcurrents of ~1 mA/cm2 using carbon cathode and anode. Effects of temperatures, flow rates and electrical currents have been investigated. As a result, we found that the LiCoO2 films and Co3O4 films were successfully fabricated on paper and/or porous PTFE filters at 120 °C, while CoOOH films were deposited at 80 °C. Furthermore, LiCoO2 films did not cover whole the substrates, but was fabricated just over the anode. The chemical reactions of electrodeposition were also considered from these results.IntroductionRecent agreements on global environment require rapid progress of low energy and low waste processings for the fabrication of thin films that succeed to the mass production with the high consumption of the fossil fuels (such as physical vapor deposition°, chemical vapor deposition2), dip coating with firing3) etc.). The total energy consumption in aqueous systems should be the lowest among all these processing routes, because a much lager excess of energy is necessary to create melts, vapor, gas, or plasma than to form an aqueous solution at the same temperature4)The ""Soft Solution-Process"" (SSP) was one of the best concepts to realize the low energy and low waste fabrication of inorganic materials. 5) Generally speaking, SSP gives similar results to any other processing using fluids (such as vapor, gas plasma) and/or beam/vacuum processing. However, the total energy consumption of all these possessing routes should be the lowest in aqueous systems, because a much larger excess of energy is necessary to create melts, vapor, gas or plasma than to form an aqueous solution at the same temperature (Fig. 1). This idea can be easily demonstrated, using the simple example of BaTiO3. The energy diagram for the formation of BaTiO3 from various precursors is shown in reference 4. The driving forces (AG) for representative synthesis reaction of (1), (2), (3), (4) and(5) are 38, 727, 3685, 17 and —14kcal/mol, respectively at room temperature. 6' 7"

Jan 1, 2000

By William Reisz

Managing the blast site at almost any operation can be a daunting task. There are so many details that must be observed, understood, and acted upon. It goes without saying that there are no two locations that have the exact same challenges and concerns. The level and the extent of these challenges can vary widely.

Jan 1, 2014

"Energy efficiency in mining and minerals processing has attracted considerable public and industry attention because of the significant quantities of energy consumption involved. In this context the question of what are worthwhile targets for energy efficiency improvements ought to be of the highest priority. It is however worth taking a step back to avoid falling in the trap of taking preconceived ideas that have been reiterated repeatedly before as gospel. The aim of this paper is to highlight areas where new or alternative approaches could potentially be the better way forward. Some may come as a surprise to conventional industry thinking. Ultimately any such solutions are attractive to practitioners not just in an environmental but also in an economic sense, and hence should be targeted through applied research and development efforts. This paper highlights key aspects of each group of opportunities and some of the individual approaches to provide an overview of the current status quo.MINING INDUSTRY POWER UTILISATION – WHERE IS THE BIGGEST BANG FOR THE BUCK?The question of where is the biggest bang for the buck when trying to determine worthwhile targets for energy efficiency improvements has not always been reported on broadly enough, typically because industry practitioners operate in specific areas of expertise and comfort zone. Looking beyond the familiar doesn’t always come easy. Any technology or methodology consideration to address energy efficiency needs to take into account the context of alternative opportunities of superior value or risks not achieving desired uptake. The following sub-chapters have been ordered by magnitude of improvement potential as best as is possible, starting with the biggest first, and the smallest last. Some may be a surprise relative to conventional mining industry thinking."

Jan 1, 2016

By L. Gao, X. Gui

Fine coal obtained from Kailuan mine served as the processing object of this study. This material was difficult to separate. A flotation rate experiment was designed to investigate the process distribution characteristics of size and density during fine coal flotation. Size and density analyses of five clean were studied. The mineral morphology of flotation rate experiment cleaning was observed through scanning electron microscopy. The fractions -0.074+0.045 mm and -0.045 mm exhibited the best practical floatability and presented the highest combustible body recovery rates, but the selectivity and natural floatability of these two fractions were the worst. The - 0.074 mm fraction has contaminated the clean coal from the early stage of flotation, and the cumulative clean coal ash of -0.074 mm reached up to 17.20%. The low and middle-density classes displayed varying flotation behavior, but the flotation yield difference was only nearly 3%. The middle-density class caused the clean coal to have high ash content. The poor selectivity of fine coals, middle-density fraction, and fine mud resulted in high-ash clean coals during flotation. Thus, improving the selectivity of fine coal, restraining the flotation of fine mud, and grinding the coal to decrease the middle density mass fraction to liberate clean coals can yield high-quality clean coals through flotation.

Jan 1, 2014

By F. C. Blake

The apparatus which I shall describe in this paper has been in ase for some time at the laboratory of the Pennsylvania Lead Company's works, and has been found to give good results, and to be simple and convenient. Steam Bath.—This steam bath is shown by Figs. 1, 2,3 and 4. It is made of sheet copper, about one-twelfth of an inch thick, the joints being brazed, and is used for heating the bottles in which the silver samples are dissolved,-previous to the fineness determina-

Jan 1, 1882

By Debbie Marshall

Nickel and cobalt in lateritic ores can be extracted by either a hydrometallurgical or a pyrometallurgical route. The high-iron limonitic fraction of a deposit is best processed' hydrometallurgically while the magnesium-rich transitional and saprolitic fractions are more suited for pyrometallurgical processing. During hydrometallurgical processing, it may be attractive, for economic reasons, to blend the limonitic component with transitional and saprolitic ores, which contain higher nickel levels. However, blending increases the concentration of magnesium in the feed, leading to increased acid demands. The decision on how much ore to process then becomes an economic one. Ore samples with different magnesium contents were prepared for the leach test program by blending limonitic and transitional ores. The ore samples were slurried in seawater and tested in the Falconbridge Hydrometallurgical Pilot Plant. As expected, acid consumption increased with increasing magnesium content of the ore. For target extractions of 95% nickel and 92% cobalt, the required residual free acid concentration increased from 30 g/L at 1.7% magnesium to 50 g/L at 2.7% magnesium. When the magnesium content was raised to 3.8% and 4.6% in subsequent pilot plant testing, the final free acid requirements did not increase beyond what was observed at 2.7% magnesium. Thus, the cut-off ore composition to maximize nickel units and minimize acid requirements is between 1.7- 2.7% magnesium. Keywords: high pressure acid leaching, laterites, magnesium

Jan 1, 2004

By Eric Kelley

Having been retained as a legal expert for the fatality at the Canberra, Australia project, it made me aware of how good intended blasters profess to be implosion experts. Owners and contractors can be misled by these representations, seeing a video of Directionalized Structures constructed of reinforced concrete may be impressive to watch, but lack sound evidence of the true mechanics of an actual “implosion”; on steel structures more prevalently. If any well intended blaster comes to a determination that he can implode a structure, it should be not be construed he cannot. It should be well investigated that the specific blaster has verifiable experience. What happened in Australia reflects on all end users of explosives. I have heard a direct quote in our project in Alberta, “We don’t want to have what happened in Canberra”. Such a tragedy could have, and should have been avoided. Simple by using the “Right Tool for the Job”. We should sideline egos and economics. Would any competent blaster compromise his or her reputation, company or insurability? More importantly, have an honest conscience knowing that if the proper explosive is available, use it, don’t shortcut it. If possible expand the schedule. Better, yet, examine all avenues before the project, and last, cancel the project. A human life is our best asset and should not be compromised.

Jan 1, 1999

The U.S. Code of Federal Regulations (Title 30) requires that a methane monitor be placed on every mining machine to continuously observe and record methane levels at the face. The monitor must provide a warning whenever methane levels are 1.0 percent or higher. An effective monitoring system will indicate a methane concentration of 1.0 percent on the mining machine before methane levels at the mining face reach 5.0 percent. Where the methane monitor is located on the mining machine is one of the most important factors that determines how effectively face methane levels can be predicted. Any change in the sampling location will result in a change in measured methane concentration. To protect the methanometer, it is usually located on the cutting boom at least 1 to 1.8 m (3 to 6 ft) outby the front cutting bits. A face ventilation system using blowing tubing was simulated in a full-scale test facility. Methane released from the face area was monitored at multiple locations on a model mining machine as well as locations near the face. Based on the relationship between concentrations measured on the machine and at the face, criteria were developed for selecting the best machine locations for monitoring methane. Recommendations are given for revising methane action levels for alternative sampling locations.

By John C. Machisak

THIS PUBLICATION presents injury experience and employment data for the nonmetal mining industry in the United States for 1960. Data for the mines and mills are presented separately, as shown in the list of tables. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry for their voluntary submission of injury and employment data. As the information submitted contributes largely to the promotion of safety in the industry, special effort has been made to ma e these questionnaires as complete as possible.

Jan 1, 1963

By M A. González, J A. Romero, D L. Fuentes, C J. Poblete, O Abdrashitova

"Robustness can be defined as the ability of a system to resist change without adapting its initial stable configuration. Robust design methodology, which is widely accepted in the manufacturing industry, allows the establishment of robustness and reliability metrics in scenario analysis.In the mining industry, a mine can be considered as a system with design parameters such as processing plant and mining capacities. Traditionally, a limited number of scenario iterations are performed in an attempt to determine optimal capacity values. An important strategic decision such as process plant capacity in particular is made during the very early stages of a mining study, often based on a low level of information. Lack of time and tools to run and analyse a larger number of possible scenarios for different design parameter combinations are usually the main reasons for not performing a full analysis. In addition, the uncertainty of other mining study input parameters creates more risk in decision-making.With advances in technology, it is now possible to automate the process of generating several thousands of scenarios in an affordable and timely manner. This allows performing the results analysis and assessing robustness and reliability criteria within a reasonable time frame. It is possible to generate a surface of results based on the net present value (NPV) for each scenario. This surface will reflect the efficiency level of the capture of the economic rent for each production scale. In addition, each scenario can be tested under diverse conditions of volatility of other external variables such as prices, costs or recoveries for example.This paper aims to establish a methodology that applies robustness criteria to determine the best scenario on several surfaces of value, which is then assessed with real data from a mining project. Obtained results demonstrate the advantages of using the proposed methodology in dealing with the above-mentioned multidimensional problems. It allows better decision-making on key design parameters and better control of the risks of a strategic mine plan.Citation:Poblete, C J, González, M A, Romero, J A, Fuentes, D L and Abdrashitova, O, 2016. Use of Robust Design Methodology for Production Scale Definition in Open Pit Mining, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 284–291 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By D. G. Eskin

"It is well known that it takes some time for the solid phase to completely dissolve upon melting, especially inside the defects of insoluble particles, e.g. oxides. Until then the oxides remain active solidification substrates in the case of subsequent solidification. It is also known that ultrasonic melt treatment causes grain refinement through activation and dispersion of solidification substrates (one of the mechanisms) and also accelerates the dissolution of solid metal in the melt. In this study we combine these effects and demonstrate that the introduction of an alloy rod into the matrix melt of the same composition results in significant grain refinement, this effect being increased by the ultrasonic vibration of the rod. The achieved grain size is comparable to that obtained by a standard Al–Ti–B grain refiner. All samples were cast using a standard TP-1 mould to enable correct comparison. The effect of the temperature range of the rod introduction, as well as the effect of ultrasonic vibrations are discussed.INTRODUCTION The fact that by introducing solid metal into the melt one can achieve structure refinement is rather well known. As early as in the 1930s–1950s a series of papers and patents have been published, showing the benefits for grain refinement when dissolving solid metal in the melt before solidification (Danilov and Neimark, 1938; Scheil, 1956). Later on this way of structure refinement was developed further and dubbed “suspension casting” or introduction of “internal chills” (Madyanov, 1969; Zatulovsky, 1981). The solid metal was added in a form of cut wire, cut sheet, or powder, with the resulting grain refining, elimination of columnar grain structure in ingots and castings of steel, copper and aluminium alloys. The underlying mechanisms have been suggested as (1) rapid cooling of the melt due to the latent heat consumption upon melting of the solid metal with the resultant melt undercooling and (2) introduction of many solidification substrates in the form of crystal fragments and active non-metallic inclusions (Danilov & Neimark, 1938; Balandin, 1973). A number of patents have been filed where either the same solid alloy or a master alloy with additions (e.g. Ti for Al alloy) is introduced in the amounts up to 50% (typically less than 10%) into the melt close to the liquidus temperature (Schmidt, 1966; Talbot & Soller, 1973, Krupp, 1974; Bondarev, 1979). The main reason that this technique is not widely used in industry is the possible incomplete dissolution of the solid parts introduced into the melt with ensuing inhomogeneous as-cast structure and potential defects. Also the selection of the temperature range where the technology works the best is not clear."

Jan 1, 2018

By H. E. Criner, M. G. Driessen

Maurice Rey—The influence of cyclone diameter upon the fineness of separation is an important point which, however, cannot be discussed adequately if the injection pressure or the rate of flow are not specified. Perhaps some light can be thrown on the matter by using the formulas derived by Dahlstrom. Let us consider several geometrically similar cyclones where the apertures e and b are equal and proportional to the diameter D and which are operated with the same pressure drop. Eq 8 of Dahlstrom's paper can be written: Q Q = K D'. " or. if F is constant: Q = K D18 K is a constant of proportionality. Introducing this value of Q in eq 13 gives elimination efficiency = K D ,41 Elimination efficiency, in the terminology of Dahl-strom, means the diameter of particles, in microns, which divide equally between the underflow and the overflow. This denomination is regrettable and it would be preferable to call it diameter of separation or characteristic size or any other name connoting a size rather than an efficiency. Whatever the name used, the above equation shows a slow increase in the fineness of separation when the diameter of the cyclone decreases. For example, if a 14-in. cyclone gives a 400-mesh separation (37 microns), geometrically similar cyclones, having the same pressure drop will give separations at the sizes shown below.

Jan 1, 1951

By M. G. Driessen, H. E. Criner

Maurice Rey—The influence of cyclone diameter upon the fineness of separation is an important point which, however, cannot be discussed adequately if the injection pressure or the rate of flow are not specified. Perhaps some light can be thrown on the matter by using the formulas derived by Dahlstrom. Let us consider several geometrically similar cyclones where the apertures e and b are equal and proportional to the diameter D and which are operated with the same pressure drop. Eq 8 of Dahlstrom's paper can be written: Q Q = K D'. " or. if F is constant: Q = K D18 K is a constant of proportionality. Introducing this value of Q in eq 13 gives elimination efficiency = K D ,41 Elimination efficiency, in the terminology of Dahl-strom, means the diameter of particles, in microns, which divide equally between the underflow and the overflow. This denomination is regrettable and it would be preferable to call it diameter of separation or characteristic size or any other name connoting a size rather than an efficiency. Whatever the name used, the above equation shows a slow increase in the fineness of separation when the diameter of the cyclone decreases. For example, if a 14-in. cyclone gives a 400-mesh separation (37 microns), geometrically similar cyclones, having the same pressure drop will give separations at the sizes shown below.

Jan 1, 1951

By K. C. Corin, M. S. Manono, J. G. Wiese

"It has been suggested that hydroxo species, particularly those of calcium, selectively adsorb onto gangue minerals. Such species enhance the depressive action of carboxymethyl cellulose (CMC) onto gangue via an acid-base interaction between the positively charged mineral surface and the negatively charged CMC molecule. Thus, the hydrophilicity of gangue minerals is enhanced, preventing the dilution of the concentrate. However, as there is little evidence to support these claims it is important to investigate. Adsorption data and mineral surface charge analyses will allow a fundamental understanding into how electrolytes and their ionic strengths affect gangue-depressant adsorption. It is strongly anticipated that decoupling these effects will allow process operators to tailor their process water quality needs towards best flotation operating regimes and in the long run effect closed water circuits. Thus, using talc and pyrrhotite as proxies, this work investigates the influence of the ionic strength of process water on the adsorption of CMC onto minerals in sulphide flotation.INTRODUCTIONThe phenomenon of gangue depression in mineral flotation is of critical importance as regards the attainment of a required concentrate grade. This thus suggests that the depressant of choice has to have a highly selective affinity for the targeted gangue minerals. This would ensure the necessary prevention of gangue from reporting to the concentrate without inadvertently depressing the value bearing mineral. The chemistry of the environment regulates the manner in which gangue depression occurs. In sulphide flotation, polysaccharides are used as depressants of choice to depress naturally floatable gangue which may in the case of Merensky ores exist as talc. The two widely used polysaccharides in the South African context are carboxymethyl cellulose (CMC) and modified guar gum. It is suggested that polysaccharides depress gangue by rendering the surface of gangue hydrophilic or by preventing the formation of hydrophobic layers on gangue mineral surface, forming large gangue aggregates and thereby increasing their heterocoagulative nature (Shortridge et al., 1999)."

Jan 1, 2018

By S. Wegerer, M. Semel

The search for minerals typically starts with a reconnaissance phase. After finding a promising target area, further prospecting work will be conducted. Finally with growing confidence of having encountered an ore deposit with commercially viable concentrations of relevant minerals, an extensive exploration campaign will verify its potential. Best practice and reliable, efficient tools for mineral resource estimation of massive sulfide deposits in the deep sea have to be established yet. Therefore, a new seabed exploration system is in development. Various challenges are caused by the extreme environmental conditions in the deep sea and by the nature of massive sulfide deposits. Information of past and ongoing expeditions were gathered to form the basis of an in-depth requirement analysis. System functions and corresponding process times were derived. The experience from the existing MeBo seabed drill rigs serve as starting point for the concept study and following development. Initial MeBo system was built for maritime research purposes and now has to be converted into a new design, suitable for efficient and economic resource exploration. The new system configuration is modular structured to adapt easily to different application scenarios and challenges. To achieve an extension of the deployment depths, the overall equipment weight has to be limited through light weight construction and material. The drilling module contains a range of geotechnical coring tools to face the varying soil conditions of heterogeneous massive sulfide formations. The major challenge to overcome is the touch down sequence on uneven, 25° inclined, rough terrain in up to 4.000 m water depth. Furthermore, high precision of the final unit positioning is necessary. Landing sub-system proof of concept is validated in laboratory environment with small scale model. A novel seabed exploration system capable to land and operate safely on highly inclined slopes of mineral deposit is described. Obtaining high quality samples by wire-line coring technique is the objective.

Feb 22, 2026

Although the mining of metals was well established by the time of the Roman Empire mining skills did not really advance greatly for many centuries. Miners did not have the scientific knowledge to distinguish minerals, to process them, and to obtain the best recovery. Each mine essentially developed its own methods in isolation, most of them dangerous. However, with the beginning of the industrial revolution in the early 18th century there was a rapid increase in mining activity in Central and Western Europe and an accompanying need to educate professionals in the developing fields of science and technology. There was also a need for specialised schools (for example, Schools of Mines) to accomplish this since the universities of the time, formed as early as the first half of the 12th century, were cloistered institutions, focused on the study of classics, theology and law. The earliest attempts at organised technical education were made in 1702 with the establishment of a School of Mines in Frieberg, Germany (Table 1) to service rich copper mines, and in 1747 with the establishment of a School of Mines in Paris. By this time, the industrial revolution was well under way and other Schools rapidly followed, at Clausthal in the Ruhr region of Germany in 1775; in 1777 at Almanden to service the mercury mines of Spain (later transferred to Madrid); in 1780 at St Petersburg, Russia and at Falun, Sweden in 1819. The academic staff for these new institutions were often trained in the original School at Frieberg.

Jan 1, 2002

By T. Niedoba

Coal as an energetic raw material is characterized by many features that determine its quality. The data concerning coal are usually treated as independent values, despite the fact that this kind of approach is not always appropriate. In the paper the dependencies between sulfur contents and volatile components in coal and particle size and density were analyzed. The method of ordinary kriging is applied to experimental data to describe this relationship; this method can be used for particles of any size and density. An example of the application of this technique is presented for energetic coal Type 31, originating from one of the Polish hard coal mines in Upper Silesia. Results from ordinary kriging are in good agreement with experimental results. Similar analyses can be performed for other properties of coal material, such as ash content, Roga number, and moisture. On the basis of the data obtained by ordinary kriging, a more comprehensive multidimensional model is described, which can characterize certain deposits or strata from which the analyzed materials originate. This is superior to basing the model only on experimental data, which often is limited by size of the sample. The results obtained by ordinary kriging applied to various types of coal would allow more precise analysis of individual properties of the studied materials and increase the ability to determine significant differences between them. This method can be also applied to other types of mineral raw materials, such as copper ore.

Aug 1, 2013

By Manfred Hackl, Sergey Bragin, Alois Seilinger

The demand for hot rolled strip is growing in multiple ways. To remain competitive, new and existing mills must meet arisen challenges in the best possible way. The production of hot strip is a key element of steel production. Since close to half of all steel produced is hot-rolled to strip, mills require maximum throughput and availability combined with geometrical precision and the ability to create optimum material properties. Today there is a clear trend in developing new steel grades with high-strength and improved formability, like 3rd generation AHSS (Advanced High Strength Steels), as well as a trend to produce thinner and wider gauges. This trend challenges hot strip mills because it requires new technologies which provide more flexibility in metallurgical treatment during the rolling process. In order to meet and promote these trends Primetals Technologies is currently working on different concepts and solutions. One example is the development of a new mill stand technology Flex-HI HOT which allows to adapt the last finishing mill stands by efficiently switching from 4-high to a 6-high mode with small work roll diameter based on production needs. Another solution is to apply a permanent 6-high rolling stand at the end of the finishing train. A smaller work roll diameter allows to achieve higher specific thickness reductions and deformation rates resulting in significant thinner hot-strip gauges with valuable metallurgical benefits. The developed solution concepts with technological and metallurgical benefits will be presented in this paper.

Oct 1, 2019

By Terrence R. Udland, Russell D. Call

"Honored with a DFI 2006 Special Recognition Award, the Four Bears Bridge was constructed across Lake Sakakawea and opened to traffi c in September 2005. The very large lake size and severe winter conditions required an effi cient foundation design capable of resisting extreme ice loading and able to be effi ciently constructed in waters up to 90' deep (27.4m).DESIGNING FOR EFFICIENCYLocated in a remote area of North Dakota, the Four Bears Bridge replacement was a major undertaking for the North Dakota Department of Transportation, with dual goals of providing a new structure that would endure a severe environment, while enhancing the natural beauty of the area. Competing bids would achieve the best price for the owner, challenging the design team to creatively solve the engineering challenges unique to the site. Foundations for North Dakota’s new Four Bears Bridge had to accommodate water level fl uctuations of up to 40 feet (12m), along with extreme ice loading and be effi cient in order to be the low cost solution at the time of bidding. All three major criteria were achieved through the use of an effi cient ‘fl oating’ lost precast concrete cofferdam founded on steel pipe piles, which allowed the contractor to achieve the project schedule. The result is an award-winning bridge that is contextually sensitive to the environment. The bridge aesthetics pay tribute to the Three Affi liated Tribes, the Mandan, Arikara and Hidatsa, who reside on the Fort Berthold Indian Reservation, adjacent to the bridge site.The original Four Bears Bridge was located over the Missouri River near Elbowoods, the native grounds of the Three Affi liated Tribes. Construction of the Garrison Dam in the early 1950’s created Lake Sakakawea, a fl ood control project on the Missouri River, and resulted in the area being fl ooded. The bridge, along with many tribal members, was relocated to a site near New Town. The bridge provides the primary crossing of Lake Sakakawea and is a critically important transportation element for the residents of the Fort Berthold Indian Reservation. The relocated bridge had become functionally obsolete and not replacing it would require a detour of 170 miles (274km). The North Dakota Department of Transportation determined that it should be replaced. In order to achieve the most effective solution, the North Dakota Department of Transportation selected a design team responsible for the creation of competing steel and concrete designs that were competitively bid. The design team was led by Kadrmas Lee & Jackson, with FIGG responsible for the concrete bridge design, while Lichtenstein Consulting and Kadrmas Lee & Jackson completed the alternate steel bridge design."

Jan 1, 2007