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By Swapan Ghosh, Amitava Sengupta, Proloy Das

Ferro-alloys are very important ingredients used for making of quality steel with desired composition. In view of high demand in various types of ferro-alloys, it has become necessary to produce the same efficiently, safely and cost-effectively with consistent quality maintaining the anti-pollution norms. To achieve this goal, it is necessary to adopt latest process/equipment with the state-of-the-art instrumentation and automation system. A Programmable Logic Controller (PLC) based automation system with suitable Human Machine Interface(HMI) terminals along with intelligent field mounted sensing/control devices allows to monitor and control the complete plant effectively with optimum deployment of man-power. In association with this, use of process optimization controllers enables to achieve specialised functionalities of the submerged arc furnaces like material management, lining management, electrode management, power management, overall production management etc.

Jan 1, 2007

By C. Anderson, Mike Michaelis

Ammonium Nitrate (AN) - based commercial explosives are non-ideal explosives. This is because the chemical and physical structure is heterogeneous on a distance scale comparable to, and in many cases larger than, the reaction zone in the detonating explosive. Such systems consist of inter-molecular fuel-oxidizer systems. Attempts have been made to minimize the heterogeneous nature (inter-molecular distances) of these explosives; emulsion systems are the latest examples of these commercialized AN-based explosives which balance cost, utility and performance. This latter factor (increased performance) is a direct result of increasing the contact between oxidizer and fuel.

Jan 1, 2003

By Walter W. Kaufman

The braking performance of underground, rubber-tired, coal mining vehicles is evaluated. Surveys of mining equipment and braking manufacturers and underground stopping tests are discussed as they relate to this evaluation. Stopping performance recommendations are proposed.

Jan 1, 1977

By E. W. Dean, H. H. Hill

Gasoline has become of such commercial and military importance that it is now practically indispensable. This product is of special interest because, in addition to realizing its value, the Nation is learn- ing that the raw materials from which gasoline is obtained are not unlimited. ACTIVITIES OF THE BUREAU OF MINES IN PROMOTING EFFICIENCY IN THE PRODUCTION AND UTILIZATION OF GASOLINE. The Bureau of Mines has directly and indirectly worked for the conservation and efficient utilization of this important product. Some of the bureau's activities have been along lines widely different from those reported in this bulletin. The work of the bureau toward the increase in efficiency of processes for the production and refining of crude oil is too well known to need mention here. Another line of activity in which the bureau has engaged is the collection and publi- cation of statistics on refinery operations. Finally, as immediate preparation for the present bulletin, two surveys of the gasoline mar- keting situation have been made. The primary object of this bul- letin is to make available to the public information obtained in con- nection with these surveys. PURPOSE OF THE GASOLINE SURVEYS OF 1917 AND 1919. Shortly after the United States declared war on Germany the bureau collected gasoline samples in the retail market throughout various parts of the country. Information regarding the sources of these gasolines and the details of marketing them was obtained, and they were subjected to analytical tests which furnished conclusive informa- tion regarding their properties. The information obtained through this survey proved of inestimable value both to the bureau and the United States Fuel Administration, particularly in drawing up speci- fications and in ascertaining the best means of obtaining supplies of particular types of gasoline that were needed. A similar and more extensive survey was made in the months of April and May, 1919, in order to obtain data needed for the revision of the Federal motor gasoline specification. The specification adopted during the war had been the subject of numerous complaints, and it seemed desirable to determine whether or not these objections were valid before attempting revision.

Jan 1, 1920

By G. P. Salas

I.- In order to keep pace feeding its fast growing population, Mexico with only about 20% of its surface suitable for intensive agriculture, will need the application of modern foodgrowing techniques. To assure greater crop yields it will be necessary to apply more fertilizers than used at present (yearly average of 29 Kgs/hectare)** For its fertilizers production Mexico still depends mostly on imports of phosphate concentrates from Florida, U.S.A., Morocco and Spain. To reduce or eliminate this dependence on foreign providers, the Consejo de Recursos Minerales -a Federal Government exploration Institute- started in 1974 an exhaustive exploration program for phosphate deposits more amenable to commercial exploitation than the phosphatic limestones contained within the La Caja Formation of Upper Jurassic, found along the Sierra Madre Oriental. After studying literature on the origin and deposition of marine phosphate and visits to deposits in Florida, U.S.A., the Baja California peninsula was selected as most favorable for starting this program because of its geologic and sedimentary history and also for its geographic location, where the cold California and warm Counterequatorial currents meet. Exploration activities executed by FORNOS, S. A. (1956) led to the disco very of low grade phosphate (3 to 5% P2O5) in the recent beach sands along the Bahia de Magdalena (Fig. # 1). In his doctoral thesis Bruno D'Anglejan Chatillon (1965) reports the presence of nodular phosphate on the continental shelf, between Isla Margarita and the Vizcaino peninsula. He estimated reserves of up to 1.5 million tons. A Mexican-American marine exploration company attempted in 1966 the evaluation of this deposit with negative results.

Jan 1, 1978

The New Zealand Minerals Industry is small but growing. Over the next 10 years it will be facing stiff international competition for skills to support this growth, particularly from Australia who are forecasting that a further 70 000 people will be employed by 2015.   The value of commodities mined and quarried in NZ continues to increase; and the value of coal, metals and industrial minerals production reached $1.505 billion in 2006, an increase of 15 per cent on 2005. Production increases will continue à. Latest Crown Minerals statistics show that national prospecting and exploration expenditure rose to $29.9 million in the year ended March 31 2006 û an increase of 46 per cent from the $20.4 million spent in the March 2005 year. The equivalent 2001 year expenditure was only $2.48 million.   The industry already experiences difficulty in recruiting the people it needs with ongoing demand for skilled underground miners, trades people, and mining professionals. This discussion paper will outline the national context with regard to labour, skills and training. It will suggest options and provide an opportunity for conference participants to discuss the way forward.

Jan 1, 2007

By William H. Shockley

THERE was an, extensive mining and industrial exploitation of Russia, about 20 years ago, by Belgian, French and British capitalists; but the results were discouraging. It is said that the Belgian and French public together lost approximately $400,000,000, chiefly in the coal and iron industry of southern Russia. This loss is largely accounted for by the fact that most of the companies were formed, as usual in " boom " times, to sell stock; and that thorough investigations were not made. In 1906, renewed interest was taken in Russian mines, especially in those of gold and copper, and a considerable literature is growing on this subject; but as yet I have seen no account of one of the large Russian mining estates. The following notes on such property, where the conditions are so different from those in the mining regions of the United States, should be of interest This inadequate and probably somewhat inaccurate account is made up, partly from my own notes made on the ground, in the summers of 1904 and 1905, and partly from a volume on the geology and resources of the estate issued several years ago, containing surface-and mine-maps, and from a pamphlet published in 1904, giving a general account of the condition and prospects of the property. This pamphlet includes a report made by Arthur L. Pearse, a member of this Institute, in 1899. Both these books are in Russian, and were prepared by the Bogoslovsk Mining Co., which owns and operates the property. Articles in many other languages have appeared dealing with various matters connected with the estate; but I know of no other general account of it. In numerous books and articles on the Urals and Siberia, however, localities are described in which somewhat similar conditions prevail. Recent papers by

Mar 1, 1908

By Henk van der Bijl, Sean Rogers, Eugene Sidorski, Alan Carpenter

The electrode column is the heart of the submerged arc furnace. Superior electrode performance provides improved furnace performance. This paper describes the main features of the electrode column that delivers superior performance in furnaces worldwide, developed by Pyromet. Pyromet?s electrode comprises the compact slipping device, lower electrode assembly, upper and lower mantles, self-adjusting electrode seal, paste heaters, and Pyromet?s patented innovative electrode breakage detection and length determination system. Pyromet?s slipping device features compact interlocking clamping rings, incorporating fail-safe spring-loaded design. The interlocked clamping rings distribute the clamping force over a larger area of the electrode casing, preventing damage. The slipping device assembly features a low maintenance modular design that allows rapid slipping cycle times, back slipping, and compatibility with Pyromet?s electrode breakage detection and length determination system. Pyromet?s lower electrode assembly consists of the contact shoes, pressure bellows, pressure ring and heat shields. The contact shoes and pressure ring are designed for long, trouble free operation whilst the pressure bellow configuration equalise contact pressure and current distribution. Furthermore, the contact shoes incorporate a self cleaning feature, ensuring optimum electrical contact. The segmented design offers easy maintenance. Pyromet?s clients experience less down time due to longer component life. Pyromet?s remote adjusted electrode seal assembly reduces the rope seal working temperature, increasing rope life. The self compensating rope seal clamping force ensures an effective seal as the rope wears. Pyromet?s electrode breakage detection and length determination system detects electrode breaks utilising Pyromet?s electrode holder and data processing system. The length measurement system controls electrode length, eliminating the occurrence of short electrodes. The length measurement system furthermore eliminates the need for manual electrode length measurement, reducing associated production losses during furnace burn downs.

Jan 1, 2007

The range of environments which control the level of ground support required vary greatly in terms of rock type, rock structure and the mining method used. At the operating mines visited during this review the level of ground support was such that incidence of rock-fall- related accidents were rare. It was also found that methods existed to support most of the conditions encountered. The main problem areas were weak rock, major geological structures, areas of heavy jointing, high development density and areas affected by high mining-induced stresses and blasting. With stope support the level of success was much lower than that achieved in development; the larger spans and more rapid changes in geometry of open stopes compared with cut and fill stoping (where cables were originally used) led to significant problems. Before a useable design method for cable support of stope walls and pillars can be obtained the precise failure mode of the walls and pillars, and the interaction of the support and the rock mass must be investigated.

Jan 1, 1982

By K J. F Logan, P W. Leaman, B A. Tucker

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Nam San copper-gold deposit was discovered in 2011 and is a likely blind extension of the Permian age Phu Kham structurally deformed porphyry/skarn copper-gold deposit.The Nam San mineralisation is hosted within a dominantly sericite altered schist unit located to the north of the current Phu Kham open pit operation and is overthrust by an allochthonous barren cover sequence of limestone, granite and sandstone. Reinterpretation of the Phu Kham geology developed the concept of a possible telescoped porphyry copper-gold system at depth. Initial drilling intersected remobilised copper mineralisation in a basal conglomerate, confirming the concept. A reconnaissance vector array induced polarisation (IP) survey identified a deep chargeability anomaly from which a drilling target was developed from 3D inversion modelling of a detailed follow up dipole-pole-dipole anomaly. Drilling of the chargeability anomaly intersected the blind Nam San copper-gold mineralisation beneath the thrusted cover sequence.The key discovery parameters are the result of an integrated exploration program that included reinterpretation of the local stratigraphy, which developed the concept of a deep blind orebody, IP surveys capable of penetrating through the barren cover and a commitment to a deep directional drilling program to test these concepts and targets. The inferred resource remains open at depth, and further assessment will most likely be through underground development.CITATION:Leaman, P W, Tucker, B A and Logan, K J F, 2015. The discovery of the Nam San copper-gold deposit, Phu Kham, Laos, in Proceedings PACRIM 2015 Congress, pp 515–520 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By AIME AIME

EITHER the 2300 people who came to the Annual Meeting were in a better frame of mind or they were resigned to their fate, or it was a better meeting than usual. Whatever the reason, at the 1nstitute?s 148th meeting the attendance was better than ever before, things went more smoothly than in some previous years, and complaints appear to have been almost entirely absent. Patience was sometimes reauired but. almost without exception, it was forthcorning the well-known recession seems to have given many members enough leisure time to come to the meeting without depriving them of the tangible wherewithal to come.

Jan 1, 1938

By G. Warren

"In the past, smelting and refining of the precious metals recovered from ore has been generally looked upon as a small and relatively minor component of the business of gold mining. This is not surprising when one considers that the manpower, space and capital components of a gold refinery at an operating mine can be several orders of magnitude smaller than other unit operations at the same location. This philosophy is changing however, as economic and environmental pressure are forcing a re-evaluation of all aspects of gold mining and milling.This paper describes and evaluates three furnace technologies available and used by precious metal operators. The operation of arc, induction, and reverberatory furnaces are discussed and their strengths and weaknesses with respect to capital cost, impurity removal, slag quality, and environmental concerns highlighted.INTRODUCTIONIn the past, smelting and refining of precious metals recovered from ore has been generally looked upon as a small and relatively minor component of the business of gold mining. This is not surprising when one considers that the manpower, space, and capital components of a gold refinery at an operating mine can be several orders of magnitude smaller than other unit operations at the same location. Generally, gold producers will spend a great deal of effort to squeeze the last drop of efficiency out of a leach or grinding circuit via simulation or testwork but will design and build the refinery based upon past practices or industry standards. That past practices or industry standards will provide a functional refinery is undisputed; that this philosophy achieves the efficiencies that are possible or demanded in other plant operations is debatable.Environmental and worker hygiene requirements are considerations as well. Pollution control equipment can become a substantial contributor to both the capital and operating costs of a refinery and furnace selection has a marked influence upon the type and cost of this equipment. Slag characteristics and subsequent processing options available also play a role in furnace selection as precious metal slag losses and the recovery effort can greatly influence the cost / benefit analysis of a particular technology."

Jan 1, 2001

By C Thompson, D Connelly

The history of mill liners has evolved over time and this paper tracks the changes and development of liner technology. It provides an overview of the primary types of liners, the design and the materials of construction. The design of a mill liner is driven by application, materials of construction, casting technology and handling issues. The choice of solid steel, grid liners, rubber or composites and magnetic liners is based on many factors.The methods used for monitoring wear and predicting eventual change out time are many and varied. The contribution of discrete element modeling (DEM) analysis in predicting wear profile is discussed.Mill trajectory and DEM software programs are used with great effect to predict the effect of lifter height, face angle, high low lifters or mill speed. In the field, trial and operational experience is used or improvements/design concepts at one operation are applied to another. Broken mill lifters, accentuated wear and other problems can be better understood using hardness testing, chemical analysis and photo micrograph analysis of pearlitic or martensitic structure along with fracture face observations. This forms a part of the typical root cause analysis. However given correct and sound liner and lifter, feed and discharge design media selection, and materials of construction, the majority of premature liner or bolting failure is normally attributed to incorrect operational methods such as excessive high ball to feed ratio, incorrect mill speed relating to lifter ball throw, incorrect media selection, "tramp" material entering the mill charge from upstream or recirculating process and understanding the specific mill operation in question.It is hoped that this paper will benefit mill operators who are faced with challenges of improving wear life and at the same time optimizing mill throughput and performance.CITATION:Connelly, D and Thompson, C, 2013. The selection design and application of mill liners for large wet grinding mills, in Proceedings MetPlant 2013 , pp 133-140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The operations management system at Olympic Dam has evolved over a two-year period to the state described in this paper. This evolution has been driven largely by the requirements of the recent expansion of the Olympic Dam operation from three to nine million tonnes of ore per year. Such a change process demands an holistic approach to mine management and several techniques have been employed including XPAC, Mine Works Planner as well as a basic philosophy of æjust-in-timeÆ completion. The philosophies, software and tracking mechanisms for managing a large tonnage operation are described, outlining a fully integrated scheduling system from shift to shift detailed activity planning to a 20 year production plan. Moreover, the vision of production exceeding the current limit of nine million tonnes means that there are to be further developments to this state-of-the-art system in use at the Olympic Dam mine.

Jan 1, 2000

By R. Greenwood

The advent of the space age and its promise of interplanetary flight has prompted new ideas for propulsion systems that will allow maximum energy with minimum fuel weight. The use of cesium as the source of energy for such rocket flights has been found desirable. Theoretical efficiency of a rocket fuel is measured in terms of specific impulse, defined as the number of pounds of thrust per pound of propellant consumed per second. Specific impulse is usually expressed in seconds (the number of seconds for which one pound of fuel would produce one pound of thrust) although it is really a measure of total energy, not of power. The most sophisticated chemical fuels have a specific impulse of 300 to 400 sec; liquid hydrogen heated by nuclear reactor has a specific impulse of 1000 to 1200 sec. Specific impulses as high as 20,000 sec, however, are theoretically attainable with the ion rocket, in which free cesium ions are accelerated across a voltage drop and ejected at high velocity.' Characteristics of the system have been sketched by Boden.2 The desirable properties of an ion propellant are: 1) low ionization potential, 2) low boiling point, and 3) high atomic weight. Alkali metals best fulfill these requirements, and Table I indicates the superiority of cesium. The use of heavy complex ions such as UCl3 is ruled out by their instability and other disadvantages.' Despite its enormous superiority in specific impulse, the ion rocket is inherently low-powered, capable of very small acceleration. Application of ion propulsion will be limited to large rockets and spaceships on missions requiring powered flight for weeks or months and employing a separate chemical propulsion system for escape from the earth's atmosphere where power requirements are large but of brief duration. For example, Kraemer and Larson3 considered the case of an unmanned 25,000-lb pay-load placed in a 300-mile orbit by chemical rockets, proceeding thence by ion propulsion to the vicinity of Mars, where it would go into orbit once again. Calculations provide for 8500 lb of cesium for such a voyage. The question of whether such quantities of cesium will be readily available to the space program does not appear to have been considered by geologists and mining engineers. Present Production and Uses Literature on industrial applications of cesium is scanty. The metal is used in scintillation counters, photocells, infra-red detection devices, and as a "getter" in low-voltage vacuum tubes. Production is sporadic and total figures are not published, but the annual consumption is measured in pounds rather than in tons. The few pollucite deposits known, small as they are, can easily supply the present limited demand for gram or pound lots of cesium. Until recently the price of cesium was $2 to $4 per gram, but according to Chemical Engineering, cesium salts are now available at $13 to $27.50 per lb. Geochemical Distribution As a large alkali ion, the cesium ion accompanies potassium in geological processes and tends to be concentrated in the latest crystallizing fractions of potassium minerals in much the same manner as rubidium. Most of the cesium in igneous rocks, therefore, is in the micas and potash feldspars of granites, and especially in granitic pegmatites. The cesium content rises markedly in the micas of the late by-drothermal replacement stage in complex pegmatite~.' Typically, cesium is only 0.5 to 0.01 times as abundant as rubidium in potassium minerals. Rb', with a radius of 1.47 A, is close enough in size to K' (1.33 A) so that rubidium forms no minerals of its own. Cs+ is so large (1.67 A) that only small concentrations can be taken up in potassium minerals; when cesium is present in solution in larger concentration it forms the mineral pollucite, Cs3-Na2A17Si17O48.3H2O, which is known only in pegmatites. In the weathering of igneous rocks, cesium is dissolved, carried to the ocean, and apparently in-

Jan 1, 1961

This chapter presents proportionate mortality ratios (PMRs) derived from death certificate data in the National Occupational Mortality Surveillance (NOMS) database for the years 1986 through 1993. At the time this report was prepared, 1993 was the latest year for which data were available. Industry is classified under the 1980 U.S. Bureau of the Census classification system [Bureau of the Census 1982]; cause of death, under the International Classification of Diseases, Ninth Revision (ICD-9) [World Health Organization 1977]. A PMR of 100 indicates a mortality risk for a particular industry group that is similar to that for all industry groups combined. A PMR over 100 suggests a higher risk; a PMR under 100 suggests a lower risk. PMRs are subject to many factors that affect their reliability and validity and may not be comparable across populations with very different causes of death. An elevated PMR for a specified cause of death among an occupational or industry group may indicate a relationship between a work exposure and the cause of death specified. However, there are many limitations of PMRs as a measure of risk; they are most useful for generating hypotheses about exposure-disease relationships, which can then be tested in other studies. Selected PMRs are presented separately for males and females for coal mining, metal mining, nonmetallic mineral mining and quarrying (which includes nonmetal, stone, and sand and gravel), and for oil and gas extraction. All PMRs have been adjusted for age and race. In general, PMRs are presented only if the lower 95% confidence limit exceeded 100. If a PMR in an ICD-9 subcategory was above 100, however, the PMR for the larger category into which the subcategory falls is always presented and may be less than 100. PMRs can be expected to be elevated for conditions that have a high prevalence in particular occupational groups. PMRs showed elevated values for conditions known to affect miners, such as coal workers' pneumoconiosis, pneumoconiosis due to silica, tuberculosis, chronic pulmonary heart disease, and injuries. Additional findings of interest were- • An elevated PMR for myocardial infarction among male coal miners (table 2-1); • Elevated PMRs for neurologic disease in general and anterior horn cell disease, in particular among male metal miners (table 2-3); • An elevated PMR for rheumatic heart disease in male metal miners (table 2-3); • Elevated PMRs for malignant neoplasms of the digestive organs and peritoneum and for malignant neoplasms of the colon and rectum in female nonmetal miners (table 2-6); and • Elevated PMRs for non-A, non-B hepatitis and arteriosclerotic heart disease among male oil and gas workers (table 2-7).

Jan 5, 2000

By Ihsan Berk Tulu

In the Analysis of Retreat Mining Pillar Stability (ARMPS) program, the magnitude of the abutment loading adjacent to a gob area is calculated using an ?abutment angle? concept. The extent of the abutment loading is determined solely as a function of depth from an empirically derived equation. In the recommended calibration method for LaModel, it was believed that the empirical equations for calculating the magnitude and extent of the abutment load, as used in ARMPS, were the best available methods for determining these critical overburden loading values. Therefore, similar calculations were implemented in the LaModel calibration method. However, the latest in situ stress measurements of abutment loading performed in the United States and Australia have shown that there can be significant deviations in the measured abutment magnitude and extent as compared to the predicted values from the empirical formulas used in ARMPS and LaModel. It seems reasonable that the overburden geology, depth, extraction panel width, and mining height should have a significant effect on the extent and magnitude of the abutment load. However, the current empirical formulas do not incorporate many of these significant parameters into determining the abutment load on the pillars. In this paper, stress measurements from US and Australian mines were back-analyzed by using analytical and numerical methods to investigate the measured abutment extent and loading. Ultimately, it was determined that the original empirical abutment extent formula in conjunction with the original ALPS square-decay stress distribution function was supported by the case histories in this paper. Also, for depths less than 900 ft, the average 21° abutment angle was supported by the case histories; however, at depths greater than 900 ft, the abutment angle was found to be significantly less than 21° and should be calculated with a new proposed equation.

Jan 1, 2012

By J. Yuan

Ground calcium carbonate (GCC) and chemically precipitated calcium carbonate (PCC) have become important mineral-based commodities in recent years. GCC manufacturing generally requires high purity and high brightness deposits of marble, chalk or limestone as the stone source. PCC usually uses limes made from lesser quality limestone deposits. GCC products have a wide span of particle size, with a d50 size ranging from sub micrometers to as large as several inches such as those used in landscaping. PCC products are typically limited to less than 10 µm (1,250 mesh). Each PCC product has a narrowly distributed size range. GCC and PCC products tend to have higher levels of whiteness com-pared with other traditional filler and extenders, such as kaolin and talc. Published statistics of GCC production volume often vary due to the exclusion of certain size range GCC products. According to Roskill’s latest estimate, world GCC capacity was believed to exceed 56 Mt (62 millionst) during 2004 for all grades.

Jan 1, 2005

THE area dealt with in this paper is included within a radius of about 3 miles of the Poimena township. Several thousand tons of tin have been won from this field, and probably £200,000 spent in exploiting it.PREVIOUS LITERATUREThe field has been reported on by Government geologists on four occasions and several ,articles on it have appeared in the mining journals. The work done by Government geologists is summarized below:-"Report on the Blue Tier Tin Mining District and its Tin Deposits", 1886.Speaking of the tin-ore occurrences, this paper states:-"In the primary granite the lodes of tin ore occur, also dykes and belts of more recently obtruded porphyries. The really valuable metalliferous deposits may be classified as follows :-1. Lodes (of which the Lottah mine is typical).2. Dykes- (a) Indurated or hard (as shown by the formations at the Anchor and Cream Creek mines). (b) Soft (eg Hayley's Lease).

Jan 1, 1912

By John H. Weigand, Stephen V. Crum

"VIBRONICS, INC. instrumented and monitored a residential structure for response to,blasting at aMidwestern surface coal operation. The residence was owned by the mining company and was extremely close to the operation. Blasting was conducted within 120 feet (36.5 meters) of the test structure. Up to seventeen (17), four (4)-channel seismographs were used during the monitoring period. The basement walls and floor were monitored. VIBRONICS, INC. also monitored a brick chimney in the basement and attic. Structural responses were then compared to outside vibration measurements taken in the soil near the foundation."

Jan 1, 1998