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By R. E. Ray

"As real estate for new development in urban settings becomes scarce, commercial high rises are being constructed above open passenger rail tracks and vehicular roadways. Rail and roadway overbuilds are treated as tunnels requiring emergency ventilation systems for train or automobile and truck fires. The value of floor space in residential and office towers poses challenges to engineers responsible for designing fan rooms and shafts for tunnel ventilation systems within the towers. This paper describes a case study of the unique incorporation of tunnel ventilation fan plants in the overbuild structure of a passenger railyard and an adjacent roadway.INTRODUCTIONTunnel ventilation systems are required for passenger rail and transit (subway) tunnels by the NFPA 130 Standard for Fixed Guideway Transit and Passenger Rail Systems, and the NFPA 502 Standard for Road Tunnels, Bridges, and Other Limited Access Highways requires tunnel ventilation systems for vehicular (road) tunnels. Passenger rail and transit (subway) tunnels are typically ventilated with a series of shafts placed longitudinally along the tunnels to provide piston relief for normal train operations and emergency ventilation of train fires utilizing reversible axial flow fans. The shafts are incorporated in dedicated ventilation buildings that house the tunnel ventilation fans and starters, switchgear to power the fans and other equipment and systems in the building, Programmable Logic Controllers (PLCs) to control fan operation with Supervisory Control and Data Acquisition (SCADA) software, and HVAC fans and ductwork to ventilate the spaces in the building. These ventilation buildings may also provide access to the tunnels below with ingress/egress stairs for use by first responders and firefighters entering the tunnels and train or transit system passengers exiting the tunnels in an emergency. A photograph of a passenger rail ventilation building that encompasses four tunnels is shown in Figure 1."

Jan 1, 2019

By R. P. Charbonnier

"To understand the operation of jigs and other separating processes based on differences in gravity, it is desirable to analyse the motion of various particles in given media under specific conditions. A summary of the earlier theories shows that they lead to unsatisfactory or excessively complicated formulae in cases such as coal jigging. By adopting a simplified theory of the motion of particles in a fluid, the size and duration of the initial accelerated motion of a particle falling in hindered settling can be calculated. Based on this mathematical analysis, examples referring to actual coal jigging practice show that it is desirable to prolong and/or repeat, as frequently as possible, the optimum conditions corresponding to an effective acceleration of the particles. The separation is then obtained according to gravity rather than to particle dimensions, as would be the case if the velocity of the particles• were allowed to approach its terminal value. To achieve this gravity separation, it is suggested that the suction phase of the jigging cycle be artificially prolonged and the frequency of pulsations increased as much as possible for washing the coals of smaller sizes."

Jan 1, 1959

By Robert H. Clark

Introduction During the last twenty years, science and industry have been strenuously endeavouring to discover new sources and new kinds of liquid fuels and to work out suitable chemical methods for their production. One of the new possibilities for the production of liquid fuel on a large scale is law-temperature carbonization of various grades of coal. The use of alcohol as motor spirit, in spite of its relatively low calorific value, is being widely investigated. Its production by fermentation of sugars, its recovery from the sulphite liquors of the paper industry, its production directly from wood and also from calcium carbide, have all been considered. At present the most promising line of investigation would appear to be the further development of those technical processes which yield liquid fuels from coal; since science has shown the possibility of preparing all kinds of liquid fuels and even the complete conversion of coal into oils. The present paper will consider briefly: 1. The production of primary tar by low temperature carbonization of coal. 2. The hydrogenation of coal. 3. The synthetic processes of Dr. Franz Fischer.

Jan 1, 1928

By C. Holmes, T. Holmes

Engineered-in material handling problems are responsible for significant unrealized value in mineral processing plants. At the root, is a lack of awareness and understanding of bulk material handling science and how important it is, especially in early design stages. Mineral processes add value to mined raw feedstock through physical and chemical transformations in unit operations, but only if the material can flow through them. Essentially, each unit operation receives a unique feedstock and produces a unique product to be collected, transported, and fed into the next unit operation. Such material-handling systems can only be expected to achieve design throughput if the system equipment is designed to the materials’ characteristics, over their full range of conditions. This requires quantification of flow properties to support the necessary customized equipment designs. Too often, assumptions or “library values” of a material’s properties are used as the basis for flow modelling and conceptual, and sometimes even detailed, design. This is especially true for hazardous materials like uranium ore, for which the additional precautions, costs, and time necessary for safe handling are often used to rationalize postponing or even bypassing testing. The surprises that often transpire in the wake of insufficient material handling consideration can have acute and costly effects. Fortunately, there is a better way.

Jan 1, 2020

By Freislich. M., Y. Gordon

"In the changing global market scenario for raw materials for the steel industry, a number of novel iron- and steelmaking process technologies are being developed to provide the steel companies with economically-sustainable alternatives for iron- and steel-making. In addition, the steel industry is also focusing on reduction of energy consumption as well as green-house gas (GHG) emissions to address the crucial subject of climate change. In this context, it is important to assess these critical issues for the alternate iron- and steelmaking technologies that have been developed. This paper presents a comparative evaluation of energy-efficiency and GHG emissions for some selected iron- and steelmaking technologies that are being considered for implementation. In this work, Hatch’s G-CAP™ and En-MAP™ tools that were developed with the main objective of quantifying and qualifying the potential energy savings and CO2 abatement within the iron and steel industry, were employed in the evaluation conducted. INTRODUCTIONThe iron and steel industry continues to transform itself and evolve in the ever-changing global market place – the raw material scenario is constantly changing with respect to quality and quantity (availability), there is stiff competition in both global and local markets, and there is increasing pressure to address global climate change issues, especially since the steel industry is highly energy- and carbonintensive. There is growing importance of steel production in developing countries such as China and India – this means that the steel industry in these countries will play an important role in defining and shaping the future of the industry.Climate change is expected to present new risks to the steel industry with respect to ensuring a sustainable business. Legislators are proposing to limit GHG emission by placing an implicit price on CO2 emission - market-based “cap and trade”, carbon tax etc.. In this scenario, it is important for the steel companies to reduce exposure to climate-related risks and at the same time, find business opportunities within these risks. Thus, there is a need to strategically manage the climate change risks; the key steps to strategically manage climate change risks are presented in Table 1[1]."

Jan 1, 2012

By Theo Mayer

Presentation Outline Define data visualization in the context of workflow Present other industries? application and demonstrated benefits Provide conceptual tools to help you address a visualization strategy Hold 10,000 foot view ? to touch on many issues

May 1, 2008

By D. R. Rice

"The Smoky Valley Common Operation is managed and 50 percent owned by Echo Bay Mine' s Round Mountain Gold Corporation. The other partners with 25 percent each are Homestake Mining Company and Case Pomeroy. The operation in central Nevada includes an open pit, 3-stage open-circuit crushing train and heap leaching on asphalt pads. Presently, about 18,000 tons per day of 0.039 troy ounce gold per ton are transferred to the leach pads, and a similar tonnage of leach residue is transferred to a waste dump. One million tons of ore are being leached at any one time.Gold and silver cyanide are adsorbed from pregnant leach solution on activated coconut shell carbon granules. Pressure stripping desorbs values from loaded carbon to electrowinning solution.Three electrowinning cells are operated in parallel. Each contains six cathodes. Each cathode includes about 40 troy ounces (2.7 pounds) of Number 2 medium coarse steel wool. The wetted area of each cathode is about 24 by 30 inches. Solution flow is 2 to 3 gallons per minute per electrowinning cell. Average current flow is 25 amperes per cathode. The voltage is controlled in the range of 3 to 4 volts to maintain desired amperage.Twice a week two cathodes are pulled from each cell and drained. Each cathode is split into four portions. These are put in a steel pan coated with WD-40 and dried overnight.Each dried cathode portion is put into a paper sack. Each group of four sacks corresponding to a cathode is weighed together. The typical weight ratio of loaded cathode wool to new cathodes is 9 or 10 to 1. To each sack is added 35 troy ounces of silica, 45 troy ounces of anhydrous borax, 35 troy ounces of nitre, and 5 troy ounces of fluorspar. The sacks are taped shut."

Jan 1, 1986

By D. A. Sloan

"THE FIRST COMMENTATOR that I will call on is Mr. W. G. (Bill) Brissenden, Vice-President, Mines, Noranda Mines Ltd. Bill, would you care to comment.W. G. BRISSENDEN ...Mr. Chairman, Ladies and Gentlemen, I spent some time reading the four papers that were presented here, yesterday evening, and decided that the four to six minutes that I had been allotted for this afternoon were going to be pretty tough to meet. It's a very big subject and I just hope that I will be able to stay within my time limit. As has been so aptly demonstrated by the members of our panel here this afternoon young men in growing numbers continue to be attracted to careers in the mineral industry, especially to careers in mining engineering. Now from 80 the point of view that the profession may have regained its status this is indeed welcome news. However, perhaps all of the members seem to have the suspicion that the number of mining engineers that the industry can absorb is a much lower figure than previously forecast. It is said that technical school graduates are now occupying some of the jobs once considered the private preserve of the mining engineer and also that mining engineering undergraduates are having trouble locating summer employment. If these interpretations of mine are correct then we are now confronted not only with our old dilemma - whither the mining engineer - but also with an urgent need to solve it. We cannot allow our profession to become once again an undesirable one in the eyes of our youth because if we permit such a thing to happen a second time the profession may never recover."

Jan 1, 1972

By J. Kolacz

"A new sensor based sorting system has been developed, providing a possibility for laboratory scale testing and further scale-up of the separation results to the industrial operation. The new system contains different sensors as: X-ray detectors, visible light cameras, NIR cameras, ultraviolet cameras and magnetic sensors, in the same sorting unit. The sorting unit allows advanced calibration options and fine-tuning of the installed sensors to achieve the best separation effect under controlled conditions. Finally, the processed material can be analysed and separated by the rejection mechanism, similarly to the industrial scale operation. At the same time, the process is carried out with limited amount of material allowing detailed statistical calculations for processed particles and all sensor types. The optimal settings and sensor types are specified for the industrial application.The paper describes the scale up of the results achieved for iron ore and coal, where the test work was first carried out using the new laboratory sorting system and where the industrial scale sorting system has been built, in the final stage. The industrial scale sorting results showed a very good correlation between the laboratory and full scale operation. Thanks to the detailed study carried out in the laboratory equipment, the settings of the sensors in the full scale operation provided much better separation efficiency. It was especially important to provide proper setting for the X-ray sensor data calculations, which can be very critical for achieving the best results. During the industrial scale sorting of coal, the input material had 40-55% rock particles as the direct source of ash in the coal stream. The optimal laboratory unit settings and transferring these settings to the industrial sorter, provided 98.8% efficiency for removing rock particles with only few % losses of coal."

Jan 1, 2016

By Gordon Smith

ABSTRACT Gold-bearing quartz veins in the northeastern Ontario and north western Quebec mining camps are shown to have been mineralized in part by epithermal solutions. The vertical gradient of pressure during this stage of mineralization is calculated, using decrepitation temperatures of quartz and thermoelectric potentials of pyrite. The base of the Cobalt sediments, which lie uncomformably over part of the mining region, may be taken as datum level in calculating the depth of erosion into the basement below that level. The vertical extent of the epithermal gold mineralizaiton in this region is at least 9,000 feet below the datum level. INTRODUCTION IT WOULD have been difficult a few years ago to convince economic geologists that after making a series of measurements in a laboratory in Toronto, the depth of erosion which has taken place below the base of the Cobalt sediments at any place in the Ontario-Quebec mining region can be calculated to the neare.st 500 feet, or that the same series of measurements would also serve to allow a prediction of the minimum vertical depth of probable ore in a producing mine in the same region, with the same degree of certainty. Possibly it is just as difficult today, but the following description of the data and calculations may help to demonstrate the reliability of the method.

Jan 1, 1951

By J. Guha, R. Kanwar, G. Archambault, A. Tremblay

The Copper Rand Cu-Au deposit lies within a shear zone which strikes N50-60W and dips steeply southward (50°-55°) and extends over 1. 5 km with a thickness which varies form 350 to 425 metres. Mineralization, inside the shear zone, is structurally controlled by a dilation mechanism which can be explained by a fracture dilatancy model. The principle of this model involves the mechanics of overriding of irregular planes and surfaces of faults and schistosities, These structures are characteristic features of the Copper Rand shear zone. A structural analysis of the shear zone has been carried out to establish relations between the different structures within the shear zone and their evolution with the development of the shear zone. A geomechanical interpretation of the Copper Rand shear zone explains the formation of internal structures such as faults, schistosities and microstructure during the shearing. This interpretation confirms Ramsay's theoretical model on the geomechanical evolutuion of shear zone development, and the experimental work of Morgenstern-Tchalenko on the simulation of shear zones in clay models. The geomechanical interpretation of the shear zone demonstrates that at the onset, subsidiary fracture patterns are developed in second order faults in the following sequence. At peak strength Riedel shears ( R and R') are formed which propagate outside the strength, restraint (P) shears are developed in the thrust attitude within the shear zones. Principal displacement shears (D) develop toward residual strength in the direction of movement. Shear lenses are formed by the interaction of these shear discontinuities and these facilitate the formation of schis tosi ties with the continuation of the shear displacement within the main shear zone. While the main shear zone and the P and D shears within the main shear zone were in continual movement, the Rand R' structures, once formed, retained a simple fracture pattern and moved little outside the shear limits in comparison to the main shear zone. Parts of these structures inside the shear zone were reactivated by subsequent movements and deformed into folds to account for the present attitudes of the HW-1 and HW-2 and HW-3 structures. This geomechanical model for the shear zone with its subsidiary structures (R, R', P and D shears) is also applied on a larger scale to the Dore Lake shear belt and explains the different structures accompanying it. The initial development of the WNW shears (most are ore deposits) was followed by the subsidiary structures of the Dore Lake shear in a north-south stress field and is well defined by the movements characteristic of the different structures. It is concluded that the Dore Lake shear cannot be the prolongation of the McKenzie Narrows shear but it seems that this prolongation relates to the Henderson-Portage shear zone.

Jan 1, 1984

By M. Maccagni, J. Nielsen

"The recovery of lead from battery paste has been investigated for a long time and with the use of many different electrolytes. A number of processes have been presented, but none of them reached even the demonstration step. Engitec has developed a new concept for the battery paste electrowinning using a chloride electrolyte fed through a very innovative flow cell. The process has passed the lab and the demo scale and it is ready to be introduced on the market. In this paper, a description of the process will be provided.INTRODUCTIONThe need for improved energy storage systems as well as the introduction of commercially viable electric vehicles is providing a strong compulsion toward the research of new batteries. The lead battery is playing an important role because it is inexpensive, reliable and it is the most recycled material. This last aspect marks the lead acid battery as quite peculiar making it both the primary lead based product and the main raw material for lead production.In the last years the legislative pressure has become very strong and has forced the lead production to react through the introduction of important process innovations and market changes. The dispersive products, such as additives for paints and for fuel as well as bullets, have been practically banned all over the world while the battery market continues to grow. The lead acid battery remains the cheapest and most integrated energy storage system available and is improving to meet the new technical challenges. This is testified by the news coming from the development of new and more efficient lead acid batteries which are confirming their leading position.Unfortunately, the image of lead is very negative in the public opinion and some important actions are required to try changing this sentiment. Among them, better information to the market and users and the introduction of new and cleaner technologies in the production of lead can help."

Jan 1, 2016

By J. Hall Carpenter

"Wet concentration has, in the history of ore dressing, been the primary treatment method following crushing, grinding and sizing, when these have been necessary. The evolution of new methods of gravity concentration has been comparatively slow.Today, the most significant and sophisticated of the new types of gravity concentrators is, no doubt, the cone concentrator developed by Ernst Reichert of Mineral Deposits Pty. Limited in Southport, Australia. These units have now had some years of use in the field, are becoming one of the standard tools of the industry and their metallurgical results, as outlined in this paper, are out-standing."

Jan 1, 1966

By Yan-Jun Shen

The rock mass classification system, BQ (basic quality), is the only national system that is suitable to most kinds of rock engineering in China. It uses two main aspects of the rock mass, the intact uniaxial compressive strength (UCS) and the rock intactness index (KV), to obtain the rock mass BQ. The index KV could be measured by the acoustic wave method. However, because this method is an indirect approach to characterize the rock mass structure, misfits often occur between the test results and the actual rock mass characteristics. Therefore, a new parameter KGSI expressed by the geological strength index is proposed to replace the original KV, and a new method is presented to express the value of BQ as a function of the UCS and the KGSI. Then, the underground excavations at five hydropower stations were chosen as examples to study the relationship between the revised BQ and the each of the international systems (RMR, Q or RMi). In addition, the applicability of the RMR, Q, or RMi system is discussed for China?s rock characteristics and geological conditions, and suggestions are given for improving the revised BQ system.

Aug 1, 2013

High Pressure Grinding Rolls (HPGR) are said to be a good option in new grinding circuits. Due to their low energy consumption compared to other grinding systems such as SAG milling, there is a strong incentive to check their behaviour for certain ore types. With rising energy prices the operation will become even more beneficial in future. As published in the past, the HPGR is claimed to increase the liberation of the valuable mineral component within an ore. An investigation at the research centre of Polysius was conducted to substantiate the liberation behaviour in finish grinding operations. A pilot scale HPGR test unit (POLYCOM MAGRO) with a roll diameter of 950 mm and processing capacity of 80 t/h was used. Grinding tests were completed with a screen and a two stage drying air separation process (SEPOL). Analysis included standard screen analysis, fractional XRF and modern MLA technology. A technique was developed to oppose the amount of produced slimes (resuming bad flotation) against the positive effect of producing high mass fraction at flotation-easy sizes. The paper shows how effective the use of a dry grinding separation could be in terms of production of mass of liberated metal.

Jan 1, 2012

By N. Shi, T. G. Joseph

ABSTRACT One-twentieth-scale field trials for conventional and concept dipper designs were compared to mid- and ultra-class-sized conventional dipper performance. Digging effort was used as the performance indicator for comparison. It was shown that linear relationships exist between dipper capacity, suspended hoist load, and peak hoist load. A ratio of conventional and concept dipper performance at the 1/20th scale was then evaluated to allow prediction of the performance of an ultra-class concept design using an independent ultra-class conventional dipper dataset. The outcome indicated a peak hoist requirement of 15.5% less to achieve the same production as the conventional design.

Jan 1, 2011

By F. H. Hueston, R. S. Barclay

"Depending on the application, zirconia, fused magnesia and graphite have been found to be the most suitable crucible materials for melting uranium metal and its alloys. Although graphite has been found to be satisfactory for uranium and uranium alloy castings with cross sections of 4 square inches or greater, ceramic-type molds are superior for small sections and those shaped castings which prohibit the economic use of machined graphite molds. Heating cycles, addition mechanisms and furnace conditions for melting are discussed."

Jan 1, 1967

By W. Lin, Z. Z. Dong, C. L. Zhou, Y. C. Kuang

The inversion of rock mechanical properties based on well-logging data is a common method to drillbit selection in petroleum engineering, the basic principle of which is to use deep-well logging data and experimental regression model to calculate rock mechanical properties. The profile of rock mechanical properties can be established. According to the profile, the type of drillbit can be selected in different formations, which will improve the economic benefit of bit use indicators. Compressive strength of rock is one of the most important parameters. Conventional method to establish regression models of acoustic velocity and uniaxial compressive strength is on the basis of rock core sonic experiments and uniaxial compressive experiments. However, with the increase of deep drilling operation, triaxial compressive strength prediction model will play a more vital role in drillbit optimization selection in deep wells and improving ROP (Rate of Penetration). Triaxial compressive strength is an important parameter to evaluate the formation strength property. In this paper, to the sandstone commonly encountered in oil drilling, combined the rock mechanical experimental results with the changing porosity experimental results under confining pressure, a new interpretation model of triaxial compressive strength based on well logging data is proposed. Firstly, three types of sandstone samples are collected. Then measured components, uniaxial compressive strength, triaxial compressive strength and porosity. Experimental results show that: confining pressure has a significant influence on sandstone strength, with the increase of confining pressure, triaxial compressive strength increase; furthermore, the triaxial compressive strength of different porosity sandstones have different change rules when confining pressures changes; sandstone porosity decreases with the increase of confining pressure and it obeys logarithmic function. According to the results, regression models of sandstone, in-situ uniaxial compressive strength model and uniaxial compressive strength model under normal pressure are generated. Meanwhile, using well logging data in the acoustic velocity, density and gamma value can derive in-situ rock formations uniaxial compressive strength and in-situ porosity. Eventually, a new model established in this paper, containing in porosity, uniaxial compressive strength, lateral pressure and power exponent of regression, can predict triaxial compressive strength which will guide drillbit selection.

Jan 1, 2015

By Frank Mucciardi, Zhongsen Yuan

A new heat transfer technology --- termed Thermopump technology has been developed. This technology originates from conventional heat pipe configurations but has now evolved into its own class of heat transfer units, which we refer to as `Thermopumps (TP)'. A key feature is that Thermopump technology can be applied to high temperature / high heat flux environments where conventional heat pipe technology fails. Moreover, when implemented in less demanding applications where heat pipes appear to operate, Thermopump units have been found to function more smoothly and reliably. This paper will introduce Thermopump technology and several applications of this technology in steelmaking and refining will also be discussed. In addition, this paper will focus on three classes of applications: 1) waterless, non-consumable, high efficiency Thermopump oxygen lance and/or burner for EAF's, 2) Thermopump ladle lance for the desulfurization process, and 3) Thermopump cooling panels for furnace walls and roofs. Facilities equipped with Thermopump technology are expected to he better than the current corresponding ones in terms of increasing productivity and energy efficiency while at the same time lowering operating costs.

Jan 1, 2004

By Mi, Dong Liang, Jingyuan Bai, Victor Zhou, Xujun

Squirrel cage induction motors are the mostly used motors at present. Currently, the rotors of the squirrel cage induction motors are produced by aluminum die casting technique with the advantages of low cost of rotors. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size. Considering the huge quantity of motors, the die casting process is the best solution to produce copper rotor with economic cost. Because of the characteristics of copper, it is difficult to produce copper rotors by casting similar to that done in aluminum rotors. In order to improve the die casting quality of copper rotor, a new tooling structure was developed and the casting process of copper rotor was simulated and analyzed by Any-casting software. The filling process, solidification process, inner gas distribution and residual melt modulus were analyzed. It was found that the design of symmetrical runner and inner runner on both sides was helpful to reduce the impact of molten copper to the cavity surface during the filling process. The use of Slag traps array can reduce die casting defects inside the end rings. That will be helpful to improve the rotor quality. INTRODUCTION Squirrel-cage AC induction motors are most widely used in the world. In 2017, the total installed capacity of AC motors in China has reached more than 1.2 billion kW, and the annual power consumption accounts for about 60% of the total national electricity consumption. To improve the efficiency of squirrel-cage motor will be helpful to energy conservation and environment protection. There are several ways to improve efficiency of induction motors, using copper rotor is one of the most effective solutions. It is well known that the copper’s electrical conductivity is around 40% higher than that of aluminum. If copper is used to replace the current widely used aluminum in rotors, the total loss of motors will be reduced, hence increasing the overall motor efficiency. Copper rotors can be used to produce high efficiency and even super premium efficiency motors without enlarge the motor frame size.

Jan 1, 2019