Search Documents

By B. Moudgil, M. Bogan

A bench-top centrifuge was used to study the consolidation behavior of phosphatic clays. A mathematical model (based on, first-order kinetics) was developed to describe the relationship between the void ratio (at any time) and the effective stress. The permeability of the sediment as a function of the void ratio is also described. The results of this analysis are then compared to data obtained by other consolidation testing methods. The centrifuge results indicate that consolidation data may be developed in a short period of time (hours) as compared to days or weeks when other techniques are used.

Jan 1, 1997

By A C. Robertson

Studies by Tennent, Isokangas Pty Ltd (TIP) have indicated that underground quarrying of backfill may be a cost competitive option for providing backfill for specialised situations in underground mining. Situations where suitable bulk fill material may not be available on the surface, and where the total cost of setting up a fill distribution system are prohibitive, could favour the mining of fill material underground adjacent to the stopes being mined. Considerations include environmental impact, scheduling, surface constraints and total costs. The examples quoted in this paper, and the case studies are based on the authorsÆ personal observations and experience.

Jan 1, 1998

By Thomas Marcher

Stanford Linear Accelerator Center (SLAC) is located in Menlo Park, CA. In order to allow for enhanced experiments, the current facilities required expansion. Tunnels were excavated through very weak sedimentary rock interspersed with uncemented zones (Ladera Sandstone) employing the principles of the NATM. The overburden var-ied from 10 to 80 feet. The paper addresses the characterization of Ladera Sandstone that can exhibit the properties of dense sand and weak rock. The paper focuses on the challenges that were encountered during the NATM initial support design and the construction phase including the geotechnical instrumentation, monitoring and design verification process in particular the excavation of the junction between access tunnel and the FEH cavern (49 ft wide by 32 ft high).

A brief introduction is given of the scale and of some special features of South African gold mining; it is noted that great depth of mining and narrowness of the reefs, and hardness and abrasiveness of the rock are the main sources of the problems of the industry. The most inhibiting problems are: Excessive rock pressure occcurring in conjunction with rockbursts, hot and humid working places due to high virgin rock temperature and auto-compression of the air, and low level of productivity. Conventional solutions applied ordinarily in mining do not promise to eliminate, or even alleviate, these difficulties.

Jan 1, 1985

By Cong Shi, Cuiping Li, Enji Sun

"Tailings dam is a subsidiary facility of mining production. In order to decrease tailings dam accidents caused by the failure of flood drainage system, this paper proposed a framework of potential failure detection system of tailings dam flood drainage facility based on three dimensional panorama technology. A collection device of three dimensional panorama is designed to capture the onsite images of flood drainage system of tailings dam. The spatial information of flood drainage facility of tailings dam is recovered through projecting the image information to spherical surface by using three dimensional panorama technology. Two dimensional images are transformed into three dimensional images in three stages of panorama images process, which are pretreatment, registration and splicing. Combined with the framework of HTML5, panorama images are embedded into webpage. These web pages have the functions of user interface that the images could be displayed, moved and zoomed. With the function of interaction with panoramic display, 3D panorama scenes can be changed and scaled. Browsing the webpage is helpful to find potential risks such as possible holes, fractures and leakages of flood drainage system of tailings dam. The realization of this system can detect the potential safety risks of flood drainage system of tailings dam. The application of this system would improve the safety and provide the ability of accident pre-warning. It is useful to maintain the healthy and sustainable operation of tailings dam.Introduction It is reported by Xie et al (2009) that tailings dam are necessary facilities for mine production and places which constructed by damming troughs or encirclement used to store tailings that eliminated after ore selection in Metal and non-metallic mines. It is reported by Mei (2012) that tailings dam is a dangerous source of high-energy man-made debris flow, the collapse of the tailings dam takes devastating damage, which seriously threatens the safety of life and property of the enterprises and the downstream residents. It is reported by Dong (2011) that the collapse of the tailings dam causes secondary disasters such as environmental pollution at the same time. It’s a serious impact on regional economic development and social stability. The phenomenon of collapse of destruction is general excessively of tailings dams in China. It is reported by Zhang et al (2011) that most of these phenomena are caused by flood over the top of dams. The main reason is the lack of capacity or the failure of the drainage system. There are also accidents caused by the failure of drainage system in foreign countries in recent years. For example, November 5th 2015, the tailing dams collapsed because of the insufficient drainage capacity of the Germano mining area in Germano Mariana area in central Minas Gerais state in Brazil. After a small post-earthquake, the liquefied tailings fill sand submerge downstream cities and towns. It finally destroyed 158 houses, killed at least 17 people, polluted 663km river and destroyed 15 square kilometres of land along the river. It is reported by Rico et al (2008) that it’s necessary to continuous monitor and control the tailings drainage system in order to reduce the occurrence of tailings accidents and guarantee the sustainable production of the mine. The traditional artificial detection methods of flood drainage system of tailings dam exist many problems such as heavy workload, low efficiency, and susceptible to meteorological conditions. And it is reported by Luo (2013) that the tailings dam wastewater is corrosive which result a certain disease in flood discharge facilities such as tailings drainage culvert, etc. In order to realize the effective monitoring, management and maintenance of flood drainage system of tailings dam, advanced technologies need to be used to acquire the information of collection and management of flood drainage facilities of tailings dam."

Jan 1, 2017

THE object of this paper is to review certain features in connection with the mining of narrow lodes, say up to 20 ft. or so wide. The types of ore-body to which it is intended to refer are those which occur. chiefly as fissure or shear-Iodes-that is, those lodes which are to be found in belts of country which have been subjected to dynamic stresses, resulting in the formation of cracks and fissures, into some of which has been concentrated sufficient metal-bearing material to form ores. Very frequently one of the walls of such a lode is found to be a fault, or plane of differential movement.The first point which comes up for consideration is the shaft and its position. From the information afforded by the prospecting which has been done on a lode relative to the dip, nature of country, &c., the position of the main hauling shaft can be determined. For purposes of general utility the hangingwall is generally chosen, if a vertical shaft, though, on account of freedom from creeps, the foot-wall would be safer. Vertical shafts are preferable to underlie shafts in many ways; but wherethe lode maintains a flat dip the cost of cross-cutting at the various levels becomes very heavy'. This difficulty may to some extent be modified· by sinking a vertical shaft in the hanging-wall...

Jan 1, 1912

By G. T. Pruitt, T. L. Irby, P. B. Crawford, H. Ferrell

In water flooding peripheral, center-to-edge, line-drive or water-encroachment patterns the question has arisen, "when should a producing well be converted to a water-injection well?". It is realized that, if the producing well is shut in when water breakthrough occurs, some oil could be left in an unswept area. Yet, operation to high water-oil ratios may require processing much additional water. If a well is shut in, "where should the allowable be transferred?". A review of the literature indicates that very few data are available to the engineer to assist him in answering these questions. It is the purpose of this paper to present information which may be of value in selecting the flooding technique and the injection and producing wells and in scheduling injection and production rates. Certain phases of these problems can be studied in the laboratory. The Potentiometric model is well suited for studying many waterflooding problems. This model assumes that steady-state flow exists, that the mobility ratio is equal to one and that gravitational effects are neglected.'-' The three-phase sand model also has been recognized as an effective means for studying certain reservoir problems. Both models were used in making the study reported here. This paper discusses seven cases utilizing various waterflooding techniques. Data for the first five cases were obtained on the potentiometric model. Data for Cases VI and VII were obtained by constructing and flooding an unconsolidated sand pack (a three-fluid-phase system) and by determining the swept area and cumulative oil recovery for various types of operations. APPARATUS AND PROCEDURE The potentiometric model reservoir was 30 in. long X 10 in. wide by about 1/2 in. deep. Four wells were equally spaced in a line array along the lateral center line. (See Fig. 1.) Well No. 1 initially was an injection well for each of the patterns reported. The cases studied with the potentiometric model and sand model are described herein. The laboratory sand model reservoir was a 30- 10-in. rectangular Lucite vessel packed with sand to a depth of about 0.65 in. Four wells were equally spaced in a line array along the lateral center line. The reservoir material was an unconsolidated sand into which the reservoir fluids were mixed to yield fluid saturations of 55 per cent oil, 25 per cent water and 20 per cent gas. The water was added to the sand and the material mixed, after which the oil was added. Kerosene and water, the fluids used, gave a viscosity ratio of 1.64:1. In packing the reservoir, care was taken to assure constant fluid saturations and constant porosities. A new mixture was prepared for each run. During water flooding, a colored water was injected by a constant rate pump. The injection rate was 1.1 B/D/ft of sand thickness. For this series of tests, each of the producing wells was open to the atmosphere and, as in the potentiometric model study, Well No. 1 initially was an injection well for each of the patterns. KESULTS OF POTENTIOMETKIC MODEL STUDlES Two cases (Cases I and 11) involving equal pressure injections were studied, with the following results. Case Water injection was initiated at Well No. 1; the producing wells (Nos. 2, 3 and 4) were operated at constant and equal bottom-hole pressures. When water broke through at Well No. 2 and achieved the selected water-oil ratio, Well 2 was converted to a water injection well, resulting in two injection and two producing wells. The injection pressures at Wells 1 and 2 were maintained equal and constant; pressures at the producing wells were held equal, but they were lower than those at the injecting wells. A similar process was repeated when water broke through at Well No. 3. The flood was terminated when

By Jon Huff, Jeffrey Donville, Hannah Iezzoni, Dan Stevenson

Occasionally, in the design of deep foundations for a structure, a single deep foundation element may be used to support a building column. The most common type of element used in such cases is a drilled shaft (also referred to as a drilled pier, caisson, or bored pile). However, as installation capabilities have improved, large diameter augercast piles are increasingly more common. While drilled shafts and augercast piles differ significantly in construction methods, in the eyes of the International Building Code (IBC), both are treated as cast-in-place deep foundations and must comply with many of the same code provisions. Deep foundations are required to be braced such that lateral stability is provided in all directions, however isolated, cast-in-place elements that have a diameter (D) of at least 2-feet and a length (L) not more than 12 times the diameter can be an exception. In response to the concerns raised by some member professionals, the Deep Foundations Institute’s (DFI) Augered Cast-in-Place Pile and Drilled Displacement Pile Committee took a closer look at the code and its applications, the historical development of the code language through the years and performed analytical modeling to evaluate the impact of this ratio on a pile’s stability. The question is whether the limiting ratio included in the IBC 2018 code provisions is justified, or whether different criteria should be used to determine when isolated deep foundation members are allowed.

Sep 8, 2021

By Emily Wortman-Wunder

As the 2011 president of the Society for Mining, Metallurgy, and Exploration, Inc., I am pleased to present the 2011 issue of the Transactions of the Society for Mining, Metallurgy, and Exploration, Vol. 330. A significant portion of the contribution that we as a professional society make is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME; those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2011 Transactions is the second Transactions to take advantage of new publication technologies. It appears solely in electronic format. The decision to go to an all-digital format for this longstanding publication was a difficult one, but one which will better serve the mining community. Based on the feedback from the 2010 Transactions in e-book format, I believe that the transition to the all-digital format was the proper decision. The 2011 Transactions contain some of the most interesting research from the past year, including a 10-year profile of roof and rib fall trends from the National Institute of Occupational Safety and Health (NIOSH) and a new cross-disciplinary application of the tools of epidemiology to assess and mitigate risk in coal mines . This 2011 Transactions comprise of a total of 82 technical papers (626 pages including index), including all 19 papers published in 2011 in the Technical Papers Section of Mining Engineering magazine (Vol. 63) and all 32 papers published in 2011 in Minerals & Metallurgical Processing (Vol. 28). Additionally, this volume contains 31 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All 82 technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2011 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2011

By F. M. Smith, R. H. Moore, J. R. Morrey

Electrodiffusion in y cerium reported by Henrie has been confirmed and a Preliminary estimate made of the relative rates of electrodiffusion of iron, cobalt, and nickel. These diffuse to the anode at rates decreasing in that order. In addition, copper and manganese exhibit slow, but detectable, diffusion to the anode and molybdenum exhibits detectable diffusion to the cathode. The electrodiffusion of carbon, .zirconium, antimony, magnesium , and silicon in y cerium could not be detected. Iron and cobalt diffuse in y cerium at rates proportional to the current density and with no apparent dependence on temperature. Decreasing polarization of iron and cobalt with increasing temperature, which cancels the expected rate increase, would account for this behavior. The electrodiffusion rate of iron in y uranium and in E plutonium has been measured. Diffusion of iron is anode-directed. Tin was found to diffuse to the cathode, in y uranium, at an appreciable rate. In all of these solvent metals, negative ions diffuse to the anode and positive ions to the cathode. The potential field effect appears to account satisfactorily for these results. FROM early experimental work summarized by Jost1 and Seith,2 the driving force for electrodiffusion was attributed to the potential field acting on ions in a metal. More recently, Heuman,3 Wever,4 and Huntington5 have shown that momentum interchange between conduction electrons and mobile entities in the metal contributes to electrodiffusion. Electron momentum interchange is anodically directed and the direction of diffusion resulting from the field force is dependent upon the charge on the diffusing entity. These two effects may either reinforce or oppose each other. Glinchuk6 has pointed out that momentum transfer in defect conductors should be cathode-directed and this appears to be the case as demonstrated by wever's4 work on iron. Barnett's7 work, on the other hand, indicates that, even in defect conductors, electrons show a negative E/m ratio when accelerated with respect to the lattice and should lead to anode-directed momentum transfer. In discussing this problem, Wever and seith8 suggest that defect electrons interact preferentially with activated ions so as to allow a net movement toward the cathode while still maintaining an electron momentum transfer in the anode direction. Williams and Huffine9 and Henriel0 have demonstrated that electrodiffusion may be useful for purification of yttrium and cerium. In yttrium, Williams and Huffine note that movement of several metallic impurities toward the anode is in keeping with observations in most other metallic systems and indicates that yttrium remains a normal electronic conductor at least to 1230°C. Close inspection of their data shows, however, that oxygen, nitrogen, and the transition elements diffused toward the anode, while nontransition elements diffused toward the cathode. This suggests that potential field effects may have been appreciable. The present work was concerned with the applicability of electrodiffusion as a technique for purification of plutonium, but, because of the obvious hazard inherent in work with this metal, experiments to develop the technique were carried out using cerium and uranium. The results of electrodiffusion measurements on these metals and on plutonium are reported here. EXPERIMENTAL The metal specimens prepared for this work were 6 in. long, 1/4 to 1/2 in. wide, and 1/16 to 3/32 in. thick. The uranium specimens were machined from a bar which analyzed 310 ppm Fe and the electrodiffusion of iron was followed by spectrographic and by chemical analysis. Cerium and plutonium specimens were cut from sheet rolled from ingots obtained from molten salt-metal equilibrations during which radioactive tracers were introduced. The electrodiffusion of the tracers was subsequently determined by counting methods. The specimens were electrolyzed between nickel electrodes containing resistance heaters used to equalize the specimen and electrode temperatures, thereby reducing thermal gradients. The temperature of the electrodes adjacent to the ends of the specimen was measured with chromel-alumel thermocouples which were connected to the heater controls. The surface temperature of the specimen at a point midway between the electrodes was measured with a sapphire rod pyrometer, the output of which controlled the dc power supply. This assembly was enclosed within an evacuable chamber containing a quartz viewing window. The temperature of the specimen over its entire length could be scanned with a portable pyrometer through

Jan 1, 1965

By Arturo Ressi di Cervia

From the times when men in lacustrine environments drove wooden piles into the mud to elevate their dwellings, until the beginning of the twentieth century builders reacted to the conditions found in the location of their proposed structures by attempting to distribute their loads in ways that could be supported by the foundation's soils; or, if those were unsuitable, by moving the structure, whenever possible. While many major structures were built on stable ground (the pyramids were founded on rock), others were built on [ ]

Jan 1, 2000

By Luciano Almeida de Freitas

Este artigo tem como objetivo verificar os resultados da aplicação de ações que almejam a excelência no processo de carga, descarga e transporte de minério ferro de uma empresa situada na Região do Médio Piracicaba em Minas Gerais. Esta pesquisa é um estudo de caso de natureza exploratória e documental. No desenvolvimento deste estudo foram analisados os documentos da empresa, que referem-se às atas de reunião e relatórios gerenciais. As reuniões foram realizadas pelos gestores e supervisores do processo de carga, descarga e transporte de minério para identificar falhas e apresentar ações que almejassem a excelência no processo produtivo. Por fim, os resultados foram verificados e identificou um aumento no índice da utilização física dos caminhões de 11,46%, aumento da produtividade horária de 27,5% e um crescimento da movimentação total de produção dos caminhões de 23,92%. Com isso, pode-se verificar os ganhos com a aplicação das ações implementadas, que almejam a excelência nas operações.

Oct 30, 2017

By C. O. Swanson

"OUR INTEREST in estimates of world reserves of lead and zinc is focussed mainly on the information they give about the sufficiency of metal supplies for the future. However, we soon realize that the estimates can be interpreted in several different ways. Accordingly, it is necessary to have some under-standing of the elements represented by a compilation of world re-serves, and we will start by examining the accuracy of the estimates and what they attempt to measure.Variations in Estimates of the ReservesIf we study the estimates of world reserves that have been published in recent years, we note immenediately that they vary over a considerable range. For example, an article by Shea in 1947 gave world reserves as about 36 million tons of lead and 60 million tons of zinc. Shea did not in elude the United States but I have added to his totals the estimates made by the Bureau of Mines for that country in arriving at the foregoing figures. For approximately the same date, the American Zinc Institute and the Lead Industries Association reported world reserves as about 50 million tons of lead and 77 million tons of zinc. A comparison of the two sets of figures shows a mean variation of 30 per cent. For individual countries the difference between estimates can be even larger. A few years ago the estimate of Canada's reserves made by the United States Bureau of Mines was 7.4 million tons of lead and 14.0 million tons of zinc, while the Gordon Commission reported 1 O. 7 million tons of lead and 26.0 mil-lion tons of zinc. In this case the mean variation was 55 per cent."

Jan 1, 1960

By Adam Saylor, Travis A. Shoemaker, Steve Miller

Lidar scanning has become an increasingly popular tool for documenting underground excavations; however, high costs of traditional mechanical electrical lidar hardware, software, and training have limited the frequency at which lidar scans can be performed. Additionally, traditional scanning can be time consuming because multiple scan positions are necessary. With Apple’s incorporation of low-cost mobile solidstate lidar on select smartphones and tablets, lidar is becoming more tractable for everyday construction documentation similar to construction photo collection with smartphones. Here, we describe benefits of mobile solid-state lidar and describe several practical applications for use in underground construction, such as documenting the working face, over-blast, and geologic features of tunnels.

Jun 13, 2023

By Kenneth K. Eltschlager, Richard R. Brochu

At the International Society of Explosives Engineers Annual Conference held in Nashville, Tennessee in February 1995, a Seismograph Standards Committee was established. The purpose of this committee was to develop objective performance specifications for vibration measurement instrumentation and field use practices. It was also understood that due to geology, temperature, and moisture in the soils, it is not possible to design and build an instrument to give results which are absolutely comparable for ground vibration. It was, however, considered essential to standardize instrumentation by which vibration can be measured under closely defined conditions so that results obtained by users of seismographs are always the same within stated tolerances.

Jan 1, 1999

By Laurier Juteau

"NOT TOO LONG AGO, the CIM Education Committee saw the need for an information campaign to promote interest in mineral industry careers among young people. Today, times have changed and the Committee has now placed emphasis on the definition and function of the mining engineer. This situation, we believe, is entirely normal and the change of emphasis is not due to a change in the needs of the industry but more to a diversification of these needs. In years past, the Canadian mineral industry, although a very important part of our economy, was looked upon as a specialized craft and, because of the richness of our resources, did not suffer too much from competition. Now, times have changed and we are increasingly at the mercy of the competition and damaging inroads of price fluctuations, etc. We will therefore answer the questions raised in this discussion in the light of the role played in the past and the role to be played in the future by the Canadian mining engineer. We will begin with the following premises : (a) If mining engineers are to be involved in the massive problems of society, their traditional background is not sufficient. (b) Councils for professional development are working on criteria for the accreditation of advanced degree programs in the United States as well as in Canada, and, simultaneously, three-year technology programs are being developed along with professional engineering degree programs. (c) The difference between European and American industries regarding philosophy of life is that in Europe they appreciate wisdom more than HPs while in America the HP seems to be more important. The Engineering Digest of February 1972 reported that in the United States, during June and July of 1971, the second highest rate of unemployment was for the 55 to 64 age group ( 4.1 per cent). This survey certainly applies to Canadian industry as well. (d) Degrees to be awarded in Canadian universities and technical schools in 1972 will be:"

Jan 1, 1972

By A. W. Furbank

IN reviewing the aerial cameras produced in different countries, it becomes apparent that in nearly all of them an attempt has been made to secure the greatest possible angle of view. This angle, of course, is determined by the objective. The objectives most commonly in use in aerial cameras have a maximum angle of 65º. The objective developed for this new Zeiss camera combines freedom from distortion and brilliant definition, with an angle of 95º. Aerial mapping, it is claimed, has been placed on a different economic basis, and new possibilities presented, particularly in connection with automatic stereoscopic plotting instruments, to which some short references are made. One way of enlarging the angle of view is to couple several instruments with their axes convergent, thereby producing a multilens camera. Typical of cameras of this sort in the United States is the Bagley four-lens camera, which later was developed into the five-lens camera (T3-A) of the U. S. Air Corps. More recently, in order to get away from the unfavorable Maltese cross image field of the five-lens camera, and to obtain a more practical form, two five-lens cameras were combined. By using them in tandem and rotating them by 45º relatively to each other, a ten-lens camera was produced, covering an octagonal ground area, with a total angle of view of 140º. Similar designs have been evolved in other countries. In all of them, however, a number of difficulties have arisen, quite apart from their large weight and high cost. Because of their complex mechanism, numerous shutters and magazines, and the high precision with which these parts must be interadjusted and synchronized, these cameras are far from dependable Moreover, a multilens camera by itself does not yet constitute a complete outfit for producing pictures suitable for photogrammetric survey. Because all the component pictures, except the central one, are obliques, it is always necessary to employ rectifying apparatus which transforms the marginal views to the perspective of the central one. In multilens cameras with many individual magazines, it is not convenient to

Jan 1, 1938

By Sun Chuanyao, Cao Fei, Sun Desi, Zhou Dezhi

"The research applies the density functional theory and molecule design technology to design and synthesize the novel flotation collectors for copper-sulphur separation. Density functional theory (DFT) was applied to investigate the electronic properties of O-isopropyl-N-benzyl thionocarbamate (IP-BIAN) and O-isopropyl-N-ethyl thionocarbamate (Z-200). The calculation results show that both the energy of highest occupied molecular orbital (EHOMO) and the lowest unoccupied molecular orbital (ELUMO) of IP-BIAN are smaller than that of Z-200, electronegativity of IP-BIAN is higher than that of Z-200. According to the Klopman’s generalized perturbation theory, the collecting power of the two compounds is predicted to be Z-200 > IP-BIAN, the selectivity of IP-BIAN is better than that of Z-200. Then the thionocarbamate molecular is synthesized, and the compounds are characterized by nuclear magnetic resonance (NMR). It turns out that the test result identifies the prediction after the flotation verified test of pure mineral and actual mineral. The results demonstrate that the EHOMO and ELUMO are smaller in the thionocarbamate after a nitrogen atom is bound to benzyl, the thionocarbamate has strong selectivity and low collecting power. The lower the LUMO energy of thionocarbamate is, the stronger the back donation covalent p-bond between collectors and chalcopyrite is, thus improving flotation power for chalcopyrite and selectivity against pyrite. The result proves the feasibility of design and synthesis of the novel thionocarbamate through the frontier orbital properties of the collectors.1. INTRODUCTION Thiocarbamate is a kind of nonionic polar collector and is now widely used as flotation collector for copper-sulphur separation. The flotation power of thiocarbamate to chalcopyrite is stronger than pyrite, so it has high selectivity against pyrite. The frontier orbital theory and density functional theory (DFT) has been widely applied to study the structure-activity relationship of flotation collectors [1-6]. The flotation test results can be interpreted by using the reaction energy criteria and quantum-chemical parameters, such as the energy of the highest occupied molecular orbital (EHOMO) and the energy of the lowest unoccupied molecular orbital (ELUMO) of collector [7-11]. In turn, there are rarely reports about screening the novel flotation collector, by the frontier orbital properties such as HOMO and LUMO of flotation collectors. In this thesis, we apply the density functional theory and molecule design technology to design and synthesize the novel flotation collectors for copper-sulphur separation. Based on the previous findings of the structure-activity relationship of xanthogen formats [12], it has stronger collecting ability to chalcopyrite while the xanthogen formats after a nitrogen atom is bound to benzyl. Thus, in this study, a novel thionocarbamate molecule O-isopropyl-N-benzyl thionocarbamate (IP-BIAN) will be constructed, when the group structure connected with N atom in the known collector O-isopropyl-N-ethyl thionocarbamate (Z-200) is replaced with ethyl by propyl. The collectors (IP-BIAN and Z-200) have been calculated by DFT methods in quantum chemistry. By analyzing the reaction energy criteria and the frontier orbital properties (HOMO and LUMO), this research predicts flotation performance of novel collectors (IP-BIAN), then the synthetic experiments and flotation verified tests are conducted. The research provides a new theory reference for screening out the high-effective flotation collectors of copper-sulphur separation. This technology adoption will contribute to the sustainable development of mineral resources as it shortens the research cycle of new collector molecules and reduces the investment."

Jan 1, 2018

By R. Simon

The sources of energy dissipation for concentrated loadings on rock are considered in an attempt to account for the experimentally measured magnitude of the work required to break out a unit volume of rock from the free surface of an essentially semi-infinite medium. It is concluded that most of this work probably represents the elastic strain energy developed by the loading in a much larger volume of rock beneath the loaded region than the volume of the rock fragment broken out to the side of the loaded region. This strain energy is largely dissipated in the form of stress waves generated by the high rate of unloading produced by the propagating cracks. The energies associated with the formation of the new surfaces of the cracks and with the stress waves generated directly by the loading process are computed to be negligibly small. Possibilities for improving the utilization of energy to drill rod. subject to the geometrical limitations imposed by down-hole operation, are discussed. It is pointed out that any such possible improvements would probably have to be differential ones, since each rock configuration of more favorabIe loading geometry that can be created down the hole is accompanied by a complementary configuration of less favorable loading geometry. INTRODUCTION Dislodging each cubic inch of rock from the bottom of the hole by the action of a bit requires the expenditure of an amount of energy that varies from approximately 5,000 in.-lb to approximately 100,000 in.-lb, depending on the hardness of the rock, or, more technically, upon its fragmentation strength.1 In this paper we will discuss (I) why the energy expended in drilling is so large, (2) what happens to this energy upon completion of the drilling process, and (3) what are the possibilities for reducing the magnitude of the energy required to drill rock. DETERMINATION OF ROCK DRILLING ENERGY The volume of rock removed per unit time from the bottom of a hole of diameter D is evidently (7/4)D2R, where R is the rate of penetration of the bit. If P is the rate at which work is done by the bit on the rock at the bottom of the hole, the energy required to break out a unit volume of rock is given by: Ev =(4/p) P/D2R............(i) For rotary drilling, of either the rolling-cone or drag-bit varicty, P = 2pLN, where L is the torque resistance to rotation at the bottom of the hole and N is the rate of rotation of the bit. L is essentially the same as the torque measured at the rotary table only when drilling in shallow holes. The energies expended in rotating the drill string against the frictional resistance of the walls of the hole and and against the viscous drag of the drilling fluid are extraneous to the subject under consideration, although these may be much greater in magnitude than E, when drilling in a deep hole. For percussion drilling, P = fE where f is the percussion frequency and E is the work done on the rock per impact. The latter quantity can be both computed and measured for a percussion drilling machine. 2 (Under satisfactory drilling conditions, defined in terms of ranges of numerical values of certain dimensionless parameters, E is only 30 to 50 per cent less than the impact energy of the striker.2) Alternatively, E, may be measured directly by dropping chisels shaped like bit edges, backed by rigid weights, onto the surfaces of laboratory rock samples of effectively semi-infinite extent. Under these circumstances, essentially all of the impact energy is converted to work done on the rock, and the relationships among volume of rock broken out, chisel shape, impact energy and indexing distances can be obtained.3 The values of the energy required to break out a unit volume of rock under favorable circumstances are substantially in agreement for rotary drilling, percussion drilling and drop testing at atmospheric pressure. The energy per unit volume is a quantity of the order of magnitude of roughly twice the com-pressive strength of the rock as measured by a uniaxial loading test. The phrase "order of magnitude" in this paper means from about 1/3 as much to 3 times as much; i.e., the energy per unit volume may range from roughly the same up to several times

By E V. Kislov

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Northern Baikal Ni-Cu province is located in Buryatia, south-east Siberia, and geologically is part of the Baikal-Muya volcano-plutonic belt. It is known for numerous PGE-Ni-Cu-bearing mafic-ultramafic intrusions of Neoproterozoic age formed in various geodynamic settings. All these deposits can be regarded as a single Ni-Cu ore cluster located near the Kholodninskoe Pb-Zn deposit, which is ready for mining. In addition, there are less studied, small dyke-like bodies with sulfide mineralisation that formed in a rift setting and may be enriched in Ni, Cu and PGE. Individually, the known bodies are of poor commercial value by their resources, but their close spatial association (<30 km) may make these PGE-Ni-Cu deposits economic in the future. This extended abstract seeks to provide a geological framework of the North Baikal Ni-Cu-PGE province, specifically at the north-eastern Synnyr rift hosting numerous small subvolcanic bodies with Ni-Cu sulfide mineralisation. Some small subvolcanic bodies contain industrial level Ni-Cu deposits (Shanuch, Cabanga-Musongati, Voisey’s Bay, Jinchuan, etc).CITATION:Kislov, E V, 2015. North Baikal region Ni-Cu deposits , in Proceedings PACRIM 2015 Congress, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015