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By James Vaughan

Ionic liquids are solvents of interest for applications such as electro- plating, winning and refining of metals. Of particular interest is the possibility of processing reactive metals such as aluminium, magnesium and titanium that cannot be deposited from aqueous solutions. Aluminium has been electro deposited from AlCl3 : ionic liquid mixtures at low temperatures relative to conventional Hall-Héroult smelting. Imidazolium ionic liquids are have been used in the past due to their relatively high ionic conductivity and cation stability. The less studied and less expensive phosphonium ionic liquids systems may provide a viable alternative to imidazolium ionic liquids for certain applications. New information regarding the physical properties and electrochemical behaviour of phosphonium ionic liquid systems is presented.

Jan 1, 2006

By William Hurst

THE content of this paper is a presentation of the diffusivity theory for the calculation of the water drive on an oil reservoir in which b the history of reservoir pressure with time are the essential parameters for the determination of the rate and cumulative water encroachment into a field. The paper is divided into two parts-the main portion and appendix. The main body is essentially the application of the principles underlined here to actual field data. It consists of the work plots of the radial-flow case, and includes a discussion of an illustrated problem for which the water-drive calculations are treated in conjunction with the volumetric-balance equation. The appendix is a mathematical treatment of the linear, radial, and spherical cases of water influx into a reservoir.

Jan 1, 1942

By Lloyd F, Bayley F. J

The new South Mine in the Western Deep Levels complex is destined to become an ultra deep project extending to depths of 4 200 m below surface and where rock temperatures are likely to exceed 65 ¦C. Initial estimates put refrigeration requirements at 133 000 kWR. A surface refrigeration plant with an initial capacity of 42 000 kWR has been commissioned and will be used for mining the upper levels.

Jan 1, 1988

By Dyson NF

Nickel sulphide precipitated from waste liquors at the Yabulu plant of Queensland Nickel Pty Ltd was pressure leached under various conditions. Leaching at 130¦C and 700 kPa of air dissolved 95 per cent of the nickel as the sulphate in less than 2 h. Leaching at 130¦C and 350 kPa of oxygen dis- solved 95 per cent of the nickel in less than 1 h. Dissolution was faster with oxygen than with the equivalent pressure of air. Crystallization of hydrated nickel sul- phate from the resulting clarified leachate is readily achieved. Because the sulphide pre- cipitate also contains minor amounts of iron, copper and cobalt, the crystallization product contains these metals in excess of the amounts required for electrolytic-grade nickel sul- phate. This grade of product could only be produced if the contaminants were removed prior to crystallization. Alternatively, the "crude" nickel sulphate could find a market as a feed for the electrolytic production of Ni-Fe coatings.

Jan 1, 1984

By Steven Atkin, Rens Verburg, Bryony Hansen, David McWharter

The use of paste tailings as underground backfill and for surface disposal is rapidly expanding, and with it comes the requirement to understand and predict its long-term environmental stability. This paper presents the results from a kinetic testing study performed on cemented tailings paste mixtures under both subaqueous and subaerial conditions. In addition, the effects of grainsize reduction are investigated. It will be demonstrated that the long-term weathering behavior of tailings paste is controlled by its physical and chemical characteristics, as well as its placement conditions. The testing indicates that subaqueous disposal of paste inhibits acid generation, whereas the exposed samples produced acidic leachate despite the presence of cement added to meet geotechnical requirements.

Jan 1, 2000

By C. K. Chabedi

"This paper discusses the difficulties associated with the potential exploitation of the deep multi-seam resources east of the Daarby fault in the Waterberg coalfield. The resources occur at a depth greater than 250 m and the thickness of the coal is roughly 110 m, but the top 50 m comprises coal intercalated with shale and the bottom 60 m contains five seams with sandstone and shale partings. Various factors affecting multiple seam mining at these great depths are discussed with reference to lessons learned from local and international experience on multi-seam mining. Field geological and geotechnical data was utilized to assess the stability of the roof of the seams. There is no specific rock mass rating for the Waterberg area, therefore approximate coal mine roof rating (CMRR) values were used to propose appropriate support strategies. Analysis of Multiple Seam Stability (AMSS) was used to analyse the strength of the parting or interburden between the various seams, the mining sequence, and the interaction between the various seams.The research indicated that it is possible to mine seams with a low CMRR at high mining rates using longwall mining, although support for gateroads is expected to be expensive, time-consuming and onerous to install, and will impact gateroad development rates. It will not be possible to simultaneously mine zones in close proximity and failure of the interburden is predicted, thus dangerous mining conditions are anticipated. However, it will be possible to mine just two of the eleven zones using longwall mining. IntroductionThis paper discusses the difficulties associated with the potential exploitation of the deep multi-seam resources east of the Daarby fault in the Waterberg coalfield using bord and pillar and longwall mining. Figure 1 illustrates the location of the Waterberg coalfield relative to other coalfields in South Africa, while Figure 2 shows the areas containing deep and shallow resources. The Waterberg resources are expected to contribute to South Africa’s future energy requirements, and are currently exploited at the Grootegeluk open pit mine. Grootegeluk produces coal mainly for a power station, with the higher quality product supplied as metallurgical coal. The deposit is technically unique and challenging, being a multi-seam coal deposit with a total of 12 seams over a thickness of 110 m as shown in Figure 3, including Zone 5. There is currently limited knowledge on the multi-seam mining of the deep Waterberg resources. Multi-seam mining utilizing the bord and pillar method has been practised in South Africa before, but at a depth of less than 100 m in the Witbank coalfields. Multi-seam mining in thin seams has also been performed in the Natal coalfields at a depth of less than 160 m, but mostly using bord and pillar mining and secondary mining (partial pillar extraction)."

Jan 1, 2016

By Thomas M. Drown

THE means relied on to attain uniformity in Bessemer steel may be enumerated as follows I. The appearance of the flame. II. The appearance of the slag. III. The spectrum of the flame. IV. Examination of the steel itself. At present, I wish briefly to bring forward a few considerations with reference to the last two mentioned, namely, the conditions favoring the employment of the spectroscope and examination of the steel. From the amount of careful investigation which has been devoted to the examination of the Bessemer flame by the spectroscope, both on the part of scientists and practical metallurgists, one might reasonably expect some results definite and satisfactory in their nature, first, as regards the nature of the flame, and second, as to the practical value of the spectroscope as a guide in conducting the process. We find, in fact, however, that uncertainty and confusion still exist. In Germany, where this subject has received the greatest attention, it is now very generally conceded that manganese is the cause of the well-known groups of dark bands that characterize the Bessemer spectrum. Nor is it easy to see how we can avoid accepting this conclusion, when Wedding and Von Lichtenfels have produced the manganese spectrum and found it to correspond closely with that shown by the Bessemer flame. But it is evident, on a moment's reflection, as Roscoe has recently brought forward, that manganese cannot be the only cause of the Bessemer spectrum, for we notice the characteristic bands quite as

Jan 1, 1873

By John Armstrong, Michael Savill, David Powell

Hong Kong is an intensively developed region and has the highest vehicle densities in the world. In 2000 there were 6.6 million people and 580,000 vehicles using 1,890 km of road covering the 1084 km 2 territory. The high vehicle and population densities together with the difficult terrain have seen road tunnels emerge as key components both in the current and future road transportation network. Currently there are eleven operating highway tunnels in Hong Kong, seven government owned and the remaining four “build, operate and transfer” franchises, see Figure 1. The very first tunnel was the dual two Lions Rock Tunnel completed in 1967and the latest the dual 3 lane Tai Lam Tunnel opened in mid 1998. Figure 2 shows the alignment and statistics for all 11 Hong Kong tunnels. Looking ahead, Hong Kong has embarked on the study and design of the next generation of major highways and as many as a further seven tunnels are currently under feasibility study or detailed design. This seems an opportune year to produce a broad appreciation of the fire strategy, life safety and ventilation practices in Hong Kong not only for the existing tunnels but the new standards and requirements for the next generation of Hong Kong tunnels. This paper provides an overview of the fire strategy, life safety and ventilation of Hong Kong’s existing and planned tunnels. The paper pays particular attention to the areas where the unique conditions and requirements in Hong Kong impacts on tunnel and systems design and the solutions adopted to overcome these challenges.

Jan 1, 2001

By G. H. Shefelbine

DISCOVERED during the time of the Spaniards, the Namiquipa silver-lead-zinc mines in Chihuahua, Mexico, remained idle until 1916, when mining claims were first denounced. About 1922 a Japanese company, the Santo Domingo Mining Co., was formed to mine the oxide silver ore. The company built a 75-tpd cyanide plant and mined in the area for a number of years. Because of an error in surveying in one of the company's mines situated in another district, mining was carried over into a claim owned by General Marcel Caraveo, at that time governor of Chihuahua. Santo Domingo Mining Co. lost the resulting lawsuit and consequently had no capital to continue operating at Namiquipa. Later, Ray Brown and Eugenio Caballero formed a company to operate the mine, shipping crude ore to the American Smelting and Refining Co. smelter at Avalos, Chihuahua. The cyanide plant was changed to flotation with a capacity of 75 tons per 24 hr. In 1936 the property was again closed owing to labor trouble, a drop in the price of silver, and increased water in the mine.

Jan 10, 1957

By R. W. Luhning, S. D. Gittins, J .. A. Haston

"The Underground Test Facility (UTF) project operated by the Alberta Oil Sands Technology and Research Authority (AOSTRA) north of Fort McMurray has achieved marked success in field testing mining access and horizontal well in situ recovery of bitumen from the Athabasca oil sands.Mine access has provided for effective placing and operation of horizontal wells in the oil sands from a tunnel system in the underlying limestone. Performance of the in situ recovery process, Steam Assisted Gravity Drainage, has substantially exceeded forecasts made at the start of the project. Over-all results of the program to date show great promise for horizontal well in situ technology as a competitive source of bitumen from Alberta's vast oil sands deposits. The potential economics of a commercial expansion at the site are reviewed in this paper.IntroductionIn situ recovery o f bitumen from the Athabasca oil sands has puzzled the oil industry for many year s, but a breakthrough appears close at hand. The Underground Test Facility (UTF) project initiated by the Alberta Oil Sands Technology and Research Authority (AOSTRA) has had notable success in the piloting of horizontal well processes, which offer prospects for commercial development even under the highly competitive situation facing the Canadian industry . This paper describes the project briefly and presents the potential economics of commercial development on the UTF lease."

Jan 1, 1990

By Keith Rowley, Neal Harries, David Noon

The management of risks associated with slope instability is an essential process in the safe and economic operation of open cut mines. The ?slope stability radar? (SSR) has been developed to better manage those risks. The SSR remotely scans rock slopes to continuously measure any surface movement and can be used to detect and alert users of wall movements with sub-millimetre precision. The high level of movement precision and broad area coverage of the rock face can allow for a better understanding of the geomechanics of slope deformation, including magnitude of potential failures and additional warning time of impending instability. Additionally, radar waves adequately penetrate through rain, dust and smoke to give reliable measurements, 24 hours a day. SSR systems have been deployed in many mines in Australia, Indonesia, South Africa, Zambia, Chile and the United States. Greater than 70 rock falls and waste dump failures (from several to millions of tonnes) have been monitored, and on every occasion precursor ?warning? movements were recorded by the SSR. This technology enables a radical change in the management of risks in open cut mining. This paper will present recent case studies of the SSR operation in coal and metalliferous mines.

Jan 1, 2006

By E. V. Redin, B. A. Dubrovsky, E. V. Knyazev, A. I. Starikov

"Ti-V magnetite is one of the most abundant composite ore resources in the world. This ore cannot be fully processed via blast furnace technology because of high content of Ti02. According to the investigations carried out in the USA and Japan ITmk3 RHF (Rotary Hearth Furnace) technology is a breakthrough in Ironmaking. Reduction, melting and slag removal can be achieved in just 10 min. The main objective of the investigation is to establish optimum operation conditions for the production of iron nuggets from Ti-V magnetite ore via the ITmk3 by means of the lab scale testing. Samples of ore from the Maly Kuybas deposit (Southern Ural), carbon reductant and fluxes were chemically analyzed. Green pellets were processed via a lab chamber furnace to simulate RHF conditions. The nuggets and slag were chemically analyzed. This preliminary test work provides valuable information which may be used for large-scale testing in a commercially sized RHF.IntroductionThe ITmk3 process upon which this paper focuses was developed by Kobe Steel in its research facilities [l]. After pilot testing at Kobe Steel's Kakogava Works in 1999-2004 the pilot demonstration plant was built and operations were successfully carried out by Mesabi Nugget joint venture in 2002-2004. Steel Dynamics put into operation the commercial plant at the Mesabi Nugget site in Hoyt Lakes (Minnesota) in 2010. Results were consistent with nugget characteristics confirming ITmk3' s flexibility with respect to raw material inputs. At the same time, no research in the field of nugget from the Ti-V magnetite bearing ore with high content of Ti02 and Alz03 has been done. It is well known, if a lot of Ti02 and Alz03 enter the blast furnace, slag becomes viscous. The viscous slag is obstacle for stable operation of the blast furnace. Besides, high content of Alz03 raises the melting temperature of gangue minerals disturbing the coalescence of reduced iron to the nuggets."

Jan 1, 2013

A combination of new radiometric age dates, local field relationships and the regional tectonic history indicate that the low sulphidation, fault breccia-hosted, epithermal gold-silver mineralisation at Umuna is related to continental rifting processes rather than subduction induced deformation and magmatism. K-Ar and Ar-Ar age dating of secondary sericite associated with the gold-silver mineralisation indicates that the alteration crystallised between 4.0 and 3.2 Ma, whereas relative age relationships and SHRIMP II U-Pb dating of the abundant Boiou porphyry intrusions on Misima confirm that the calc-alkaline plutonism is significantly older (8.1 f 0.4 Ma) and related to a different tectonothermal event. The Woodlark Basin sea floor spreading centre occurs to the north of Misima and has continued to propagate westwards, into the continental basement of the Papuan Peninsular, since the end of the Miocene. The westernmost tip of sea floor spreading centre is presently to the east of the D'Entrecasteaux Islands but would have been to the east of Misima roughly 4 Ma. Many of the young tectonothermal features in the D'Entrecasteaux Islands (hydrothermal activity and associated epithermal mineralisation, metamorphic core complex exhumation, detachment faulting, peralkaline volcanism, half graben type basin formation) can be attributed to major extensional deformation ahead of the propagating rift system. Similar tectonothermal features on Misima are temporally associated with the epithermal gold-silver mineralisation at Umuna, suggesting that the D'Entrecasteaux Islands are a modern day tectonic analogue for Misima at the time of precious metal mobility and deposition. The rapid exhumation of high grade metamorphic rocks and localised

Jan 1, 1997

By Lu T. K

A new type of rockbolting system, the self drilling rockbolt, has been studied to develop a 'single pass' bolt for use in rockbolt installation in underground engineering. This single pass bolt forms the basis of a Rapid Face Bolting system which will reduce the amount of time spent in securing a roof during the operation of a continuous miner in the development of a panel.The installation efficiency and anchorage tests were performed in the laboratory on the self drilling bolt and the traditional resin anchorage. bolt. The results of both bolts are cmmnared.

Jan 1, 1993

By A. L. Jr. Pozzi, A. O. Garder, D. W. Peaceman

A new numerical method is proposed for the solution of multidimensional miscible displacement problems. Besides the usual stationary grid associated with numerical procedures, the method uses moving points for which positions and concentrations are computed each time step. Based on the method of characteristics for treating combined transport and dispersion, the method applies equally well to any number of dimensions and, in contrast with other numerical procedures, properly takes into account the physical dispersion, no matter how small. Extensive tests show that accurate solutions of one-dimensional problems can be obtained over a wide range of values of the dispersion coefficient, including zero. They also show that the moving points do not need to be uniformly spaced, and that increasing the number of moving points beyond 2/grid interval does not significantly improve the accuracy of the solution. Two-dimmsional calculations using the new method were carried out to simulate laboratory model displacements in which gravity caused overriding of solvent. Good agreement between observed and computed profiles and measured and computed concentrations of produced fluid was obtained for a viscosity ratio of 1.89; at higher viscosity ratios, fair agreement was obtained Computed results were found to be significantly affected by vertical dispersion, and negligibly affected by dispersion in the direction of flow, in agreement with conclusions based on experimental observations. INTRODUCTION Although miscible displacement processes are potentially of great economic significance, limited progress has been made in developing mathematical methods for predicting the outcome of a solvent flood. Because of the complexity of the partial differential equations which describe multidimensional miscible displacement, numerical methods are a natural approach to their solution. The task of finding suitable numerical approximations to one of the partial differential equations, which involves both dispersion and convective transport, has been particularly difficult. Dispersion in the absence of transport is described by the heat flow equation, a second-order equation of parabolic type. This equation has been very successfully treated by numerical methods. Transport in the absence of dispersion is described by a first-order equation of hyperbolic type. This equation has been treated numerically with some success in one dimension, both by Lagrangian and Eulerian techniques, 1.2 but extension to two or more dimensions has not been satisfactorily accomplished. Usually one of two things happens: either the numerical solution develops oscillations or it becomes smeared by artificial dispersion resulting from the numerical process. When transport and dispersion are considered simultaneously, this numerical dispersion may dominate the low physical dispersivicy that generally characterizes miscible displacement. Stone and Brian2 have developed a new difference equation for treating combined transport and dispersion in one dimension. By suitable choice of certain parameters, they succeeded in markedly reducing both oscillation and numerical dispersion. However, a satisfactory extension to higher dimensions has not yet been found. Peaceman and Rachford3 presented a centered-in-time and centered-in-distance difference equation combined with a 1,transfer of overshoot" procedure which was demonstrated to work well in one dimension. The technique was applied to the two-dimensional miscible displacement problem, but subsequent calculations with zero dispersivity showed little change in results compared with the calculations they presented. This indicates that their method involved a numerical dispersion of the same order as the physical dispersion. The present paper describes an alternate method for solving the combined transport-dispersion

Jan 1, 1965

By Ward C. W

Conventional polygonal and block modelling techniques inadequately represent the grade-thickness distribution of some narrow shear and stratabound gold deposits. The polygonal influence of high-grade drill intercepts can result in overestimates of resource tonnages at high-grade cut-offs. Although block modelling methods provide grade smoothing and a better representation of structural continuity, the technique can lack precise definition of ore width. An alternative method known as Spatial Object Modelling (SOM) has been developed on MineMap software to overcome some of these modelling issues. This method does not rely on a uniform cell size and allows grade smoothing between resource intercepts in three-dimensional space. The SOM technique creates grade-thickness bars on regular, user-defined spacings which allow easy visual comparison of raw intercept data to the interpolated model. Model cell values are readily transformed into isopachs, isopleths and resource perimeters for reporting and mine planning purposes.

Jan 1, 1997

By Samuel Tescher

The operation of gaseous mines is a problem, due to the fact that we have not only the ordinary mine accidents to guard against, but have also the ever present menace of a mine disaster involving a large number of human lives, and the destruction of valuable property. In looking over the reports of mine disasters throughout the country in the past several years, we find that methane gas, coming in contact with an ignition agency of some kind, has been the source of at least 75 per cent of our mine explosions. Coal dust, of course, plays its part in propagating the explosive action throughout the mine workings and rendering it more violent and destructive; nevertheless, the initial ignition of a body of explosive gas-sometimes of very small volume-has been the primer for the large majority of our mine disasters. We find also, that the places of initial ignition are most frequently found at the working faces, or in close proximity thereto. This is mainly due to the following reasons: First-The working faces are, as a rule, the places where methane gas is most freely generated. Second: They are places that are most poorly ventilated. Third-They are the places where ignition agencies are most frequently found. The sources of ignition, as a rule, consist of naked lights, the shooting -of shots, defective flame safety lamps, and electrical arcs. The problem, then, in the operation of gaseous mines, is primarily to so ventilate the working faces that an explosive mixture is not likely to occur, and to endeavor to keep away from the working faces all sources of ignition. To do both of these things may seem impossible. Nevertheless, by working along both of these directions, a great many disasters can be avoided. The efficient ventilation of the working faces is paramount. By efficient ventilation, we mean the continuous passing of large volumes of air at the working faces. This can only be accomplished by adequate ventilating equipment, capable of being driven by at least two independent and distinct sources of power, together with large, clean, straight air courses which are free of short turns, constructed areas, and leaky doors and stoppings. In other words, furnish a suitable course for its travel through the mine. Many of us sharpen our pencils and rack our brains to properly estimate the proper size pump and pipe equipment that may be needed to handle a certain amount of water. We estimate the size of copper conductors to a nicety. We immediately rush to repair leaks in our water, compressed air or electric lines. But how many of us give serious thought to the travel of the air through our mines, the health and safety-giving fluid on which so much depends! In driving air courses, a certain economical cross-sectional area should be adopted and maintained as standard. When turns are necessary, they should be made with long radius curves, and the cross-sectional area should be increased on the curves. All entry stoppings should preferably be built of monolithic concrete, with suitable hitches into floor and ribs, and after the concrete has set, they should be examined and leaks due to shrinkage and settling should be eliminated. Overcasts and their approaches should have cross-sectional areas larger than the entries leading to them, to allow for the sudden change of direction, bearing in mind that air wants to travel in straight lines. In the early development of a property, ample provision should be made in the size of the main entry pillars to allow for the driving of additional

Jan 1, 1925

Twelve years ago, Jeffrey Mining Machinery Division of Dresser Industries Inc. developed the 120H HELIMINER. This machine was the world's first fixed-drum continuous miner and soon became the standard among manufacturers of continuous miners throughout the mining machinery industry. This paper will first outline a brief history of continuous miner development, then discuss significant parameters which are essential to a successful continuous miner design, and finally describe a number of specific applications of Jeffrey continuous miners in a variety of materials, such as coal, potash, iron ore, and trona, around the world.

Jan 1, 1978

By Earl R. Hoskins, James E. Russell

The electrical resistivity of rocks has been studied quite extensively, in particular, the effects of temperature and confining pressure on resistivity. References 1 through 6 at the end of this chapter pertain to electrical resistivity of rock and contain further references on the same topic. The present study is motivated by an interest in determining the in-situ properties of rock as well as the stress state of the rock and how these quantities are changing with time. Most of the previous work on the electrical resistivity of rocks has been directed toward saturated rocks at relatively high confining pressures and temperatures. The present study was oriented towards air-dry surface rock that might occur in mine pillars. The mean stress and temperature under such conditions are comparatively low. It has been demonstrated that the resistivity of rock is highly dependent upon the porosity. In fact, for saturated rocks, a relationship referred to as Archie's law has been established between porosity and electrical resistivity. In the case of saturated rock, the property that is actually being measured is the resistivity of the solid/fluid system. Since the resistivity of the fluid alone is usually much lower than that of the dry rock, it is understandable that the resistivity of a saturated rock is in general several orders of magnitude lower than the resistivity of a relatively dry rocli. For dry rock, it seems reasonable that the electrical resistivity should increase as microcracks open within the material. Since microcracks open as material is stressed closer and closer to its failure point, it appears that there should be a correlation between electrical resistivity

Jan 1, 1970

A simple production technique has been initiated and implemented at Oaky Creek open cut coal mine to optimise recovery of coal from the relatively thin geological seams. The production technique is based upon minimising coal dilution through careful dragline operation and the selective use of mine mobile equipment to clean the top of coal. In addition, recovery of coal from the pits has been increased by refining blasting and dragline methods.The implementation of the recovery optimisation programme at Oaky Creek has provided significant economic benefits from increased yield through the preparation plant by the reduction in dilution, and from increased raw coal tonnage through improved pit recovery methods.

Jan 1, 1990