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By P. K. Rozakeas

It has been experimentally demonstrated that the application of electrokinetic techniques in the continuous flow of coal-water suspensions within a helical anode-cathode pipe geometry effectively causes a significant reduction in the wall shear stress. This reduction in the frictional force at the cathodic pipe wall surface is attributed to a decrease in the concentration of coal particles in this flow region caused by the migration of negatively charged coal particles towards the anodic surface(s). The disadvantage of flow-intrusive geometries is the reduction in effective flow area as well as an increase in frictional surface area caused by the placement of the anode(s) within the flow region. Experimental data is presented for a non-intrusive helical anode-cathode geometry embedded in the pipe wall which shows that a reduction in pumping energy of approximately an order of magnitude is possible. A sample of sub-bituminous black coal fines having a mean particle size of approximately 17 microns was used to prepare coal-water suspensions with a solids concentration of 50%(w/w). The practical and economic implications of this work relate to an enhanced method of long distance transportation of slurries in pipes as well as an alternative technique for continuously separating solid-liquid suspensions.

Jan 1, 2014

By Chuanlin Fan

The process of flotation separation and recycling of spent potlining (SPL) was described. On the basis of the laboratory investigations, the effects of influencing factors in froth flotation process, such as grain size, flotation agent dosage, pH value, pulp density, and dissolved components concentration, etc, were carefully studied. And the influence on environment of the process was also discussed. It was found that flotation separation can be used as an environment-friendly method for treatment of SPL residue. Carbon and other compounds (include cryolite, sodium fluoride, calcium fluoride and diaoyudaonite, etc.) from SPL were separated and recycled as flotation products respectively.

Jan 1, 2009

The Acid Drainage Technology Initiative (ADTI) was initiated in 1995 by federal agencies, the National Mining Association (NMA) and the Interstate Mining Compact Commission (IMCC) to identify, evaluate and develop cost-effective and practical acid drainage technologies. In 1999, ADTI was expanded through the addition of the metal mining sector, which is focused on drainage quality issues related to metal mines. ADTI addresses drainage quality issues from abandoned, active, and future coal and metal mines. The guiding principle of ADTI is to build consensus among industry, federal and state regulatory agencies on acid drainage technology development and technology transfer issues. ADTI is focusing its efforts on mine drainage prediction, sampling/monitoring, modelling and avoidance/remediation. ADTI is not a regulatory or policy development program. ADTI includes the Coal Mining Sector (CMS) and the Metal Mining Sector (MMS) under the overall guidance of the ADTI Operations Committee. The Operations Committee consists of representatives from industry, state and federal government and academia. The Coal Mining Sector includes two committees; a prediction committee and an avoidance and remediation committee. The Metal Mining Sector includes steering committee and work groups on prediction, sampling and monitoring, modelling, mitigation, and pit lakes. The Coal Mining Sector has produced two publications on the prediction and prevention of acid drainage. The Metal Mining Sector has workbooks under preparation covering the work group topics. This past winter, the Metal Mining Sector, working with the US Bureau of Land Management, presented a satellite training session on acid drainage. ADTI has evolved in response to changing needs and technologies as evidenced by the addition of the Metal Mining Sector in 1999. The Operations Committee and the members of the Coal and Metal Mining Sectors will guide future direction in response to identified issues.

Jan 1, 2003

By Shi Guan-Yong, Niu Li-Ping, Dou Zhi-He

"In the preset work, the viscosity model (named modified KTH model) proposed by Sichen Du and S. Seetharaman et al and extended by Shu Qi-feng was applied to the ESR slag systems. A correlation to predict the viscosities of CaF 2-(CaO)-Al203 slags using interaction coefficients of different cations in the presence of oz-and viscosity interaction coefficients between oz-and F in the presence of different cations has been developed. The interaction coefficient between oz- and F- in the presence of Al3+ was determined from the experimental data as shown in known literatures. The good agreement between the calculated viscosities and the experimental data in the CaF2-(CaO)-Al203 systems has indicated that this approach can be successfully employed to predict the viscosities of ESR slags.IntroductionReliable viscosities data of high-temperature slag melts are important for the modeling and design of high temperature metallurgical processes. Although a number of experimental measurements have been carried out, the available viscosities data is still scarce compared to the needs of today's technology, especially in the case of complex melts. In process simulations, the needs of viscosity descriptions for complex systems which could enable the extrapolation of the data as functions of temperature and composition is strongly felt today."

Jan 1, 2013

By G. M. Crosby

Seven mines with important production records in the Coeur d'Alene lie adjacent to the Gem stocks —the Frisco (Gem), Hercules, Interstate, Rex (Sixteen to One), Success (Granite), Sunset, and Tamarack. Old records are incomplete, but available data given in Table I show these mines have produced 10.550,721 tons of ore containing more than 50 million oz of silver, more than 1.5 billion lb of lead, and about 1 billion lb of zinc (approximately 1.25 million tons of lead and zinc combined). Average ore grade is 4.8 oz of silver per ton, 7.2 pct Pb, and 4.6 pct Zn. This impressive production represents about 12 pct of the District's yield. At present metal prices, with modern beneficiation, the gross value would be more than $400 million. THE GEM STOCKS The Gem stocks, considered to be outliers of the Idaho batholith of Late Cretaceous age, are located in the northern half of the Mullan quadrangle, and extend from the town of Gem, Idaho, along a strike of N30°E for a distance of approximately five miles. They occur as two major masses of monzonitic rocks commonly referred to as the North stock, which covers an area of 1.1 sq miles, and the South stock, which covers 2.6 sq miles. The areal pattern is roughly club-shaped, the North stock representing the handle and the South stock the head of the club. Two and a half miles west and five miles northeast are two groups of smaller stocks, isolated from the main masses but of the same general rock type. This discussion is limited for the most part to the North and South stocks. At the north end, where the intrusion is about 3200 ft wide, the walls are about parallel and dip very steeply west. At the south end, where the mass is about 7000 ft wide at surface, the walls dip away from each other at moderately steep angles. An aeromagnetic survey' detects and outlines with surprising accuracy the two main stocks. as illustrated on the magnetic contour map (Fig. 2). Of particular interest is the location and shape of the magnetic anomaly representing the South stock. The anomaly is centered over the south end of the outcrop, and a westerly extension joins it with a smaller anomaly over the Dago Peak stocks. The latter anomaly, likewise, is located over the south end of the isolated stocks. This pattern suggests the intrusion has greater extent at depth to the south and west. Though correlation between the Dago Peak stocks and the larger masses is suggested, the controversial aspects of the Dobson Pass fault, which separates the two areas, casts doubt on a correlation. Topographically the monzonite stocks are ignored by the drainage pattern indicating these rocks, and the invaded rocks of the Lower Belt Series react similarly to erosion. The drainage patterns of Nine Mile and Canyon creeks cut indiscriminately across the monzonite-Belt contact, resulting in both valleys and ridges in the southern end of the intrusion. Nine Mile Creek traverses diagonally the entire five-mile length of the stocks. The monzonite rocks of the intrusion are referred to locally as granite, but granite is rare and the rocks comprise a wide variety of types. Their characteristics, described in detail by F. L. Ransome and F. C. Calkins,' are summarized by P. J. Shenon.' The principal rock type is coarse-grained, light gray, porphoritic monzonite containing black crystals of hornblende. Pyroxene, epidote, and titanite

Jan 1, 1960

By Nan Wang

Based on the commercial computational fluid dynamics software, Fluent, the fluid flow and temperature field in an iron-bath reactor were simulated numerically, and the effects of top-blown and side-blown operating parameters on the mixing time of iron bath, distribution range of oxygen in top space, and post-combustion ratio were investigated. The simulated results showed that the mixing time of iron bath increased initially and then decreased with the increase of inclined degree and immersion depth of side-blown lance. The distribution range of oxygen became wider as pulling the top lance away from the iron bath. Furthermore, post-combustion ratio was reduced given the top lance was too close the bath. The simulation results provide theoretical base for the process optimization of iron-bath reactor and further development of new type iron-bath smelting reduction process.

Jan 1, 2009

By N Patel, S Narendranathan, T Mok, J Lowe

The Hazelwood Mine (HM) commenced operations in the 1950s and was originally operated by the State Electricity Commission of Victoria (SECV) prior to it becoming privatised. ENGIE, the current owners of the Hazelwood Mine ceased operations in 2017 and have since transitioned the site into the rehabilitation and closure phase, which is to encompass a full pit lake as part of the final landform. A key aspect of HM closure is the maintenance of long-term stability of the pit slopes to deliver a final landform which is safe and sustainable, particularly given its proximity to critical public receptors. The Princes Freeway, which is the primary access route to the Latrobe Valley (LV), and the Morwell Township are both located immediately to the north of the HM. With due consideration of the mine void and nearby public receptors, the authors performed slope stability assessments of critical mine

Aug 2, 2023

By D. A. Barr

High-grade gold-silver mineralization associated with electrum and argentite was discovered in a quartz vein at the Chappelle property, 273 km north of Smithers, B.C., in 1969 following a regional geochemical reconnaissance program in the Cassiar-Omineca Mountains. Subsequent exploration resulted in the discovery of numerous quartz veins with associated precious-metal values in a belt 17 by 3 km in area centrally located within Toodoggone Group volcanic and sedimentary rocks of Lower to Middle Jurassic age and a window of Takla Group volcanic rocks of Upper Triassic age. More detailed investigations, consisting principally of 5677 m of surface drilling in 57 holes and crosscutting, drifting and raising on Chapelle Vein A, has outlined a high-grade gold-silver-bearing shoot with a strike length of 200 m, an average width of about 3 m and extending to an average depth of about 40 m below surface.

Jan 1, 1978

By James Noll, Sam Janisko

Underground miners are exposed to some of the highest levels of diesel particulate matter (DPM) in the United States. Therefore, it is important to monitor the exposure of miners to DPM, but it can be difficult because of the complex composition of DPM and the number of interferences. Currently, elemental carbon (EC) is used as a surrogate because it makes up a significant fraction of the DPM and is not affected by interferences. Standard measurement methods for EC can be time consuming and only record end of shift results. In this research, a laser absorption technique that enables one to measure EC concentration in near real time was shown to be a beneficial tool. The real time data showed that the fresh air being drawn into a stone mine was not properly reaching the working area and needed to be redirected to decrease DPM concentrations. The real time data also provided a more accurate efficiency ofan environmental cab compared to just using the standard method by detecting the opening of the cab's window and door. The EC optical monitor was also worn by researchers in a mine to show how it can give not only the average concentration for the shift but also reveal when and where a miner is exposed to DPM. Keywords: Laser absorption, diesel, elemental carbon, mining, exposure

Caterpillar said it will produce a Cat line of ac electric drive mining trucks. The world’s largest manufacturer of mining and construction equipment said the addition of an AC electric drive truck line will provide its customers with products to fit key applications. “We are very proud of the strong leadership position that Caterpillar has attained with its mechanical drive trucks, and we will continue to invest in strengthening that position,” said Chris Curfman, president of Caterpillar’s Global Mining Division and Caterpillar Inc. vice president. “We also recognize that there are unique applications that would make the addition of ac electric drive an important and attractive complement to our current truck line.” This is the largest investment Caterpillar has made in mining trucks in its history.

Jan 1, 2006

By D. S. Jacobus

COMPRESSED-air motors are specially desirable, if economically practicable, for underground haulage, because they require no fuel, involve no danger of fire, and not only avoid heating and fouling the atmosphere with smoke and combastion-gases, but by the emission of expanding fresh air, cool and improve it and aid ventilation. The highest developments in the use of compressed-air motors for locomotion are to be found, in the opinion of the writer, in the principles of the Mekarski car-motor as applied to street tramways, and it is thought that notes taken regarding this system, during a recent trip to Europe, where two plants are in successful operation, at Nantes and Vincennes respectively, will be interesting to mining engineers. The plant at Nantes operates a street-line 5.2 miles long, requiring about twenty motors; the one at Vincennes about 7 miles of road. Each car at Nantes carries its own motor. At Vincennes, however, the motor-car is arranged to tow a second car containing no motor. The road at Nantes is the older, having been in successful operation for ten years, during which time neither the American consul, Mr. Shackelford, who has resided at Nantes for about five years, nor the vice-consul, Mr. Bennett, who has been at Nantes ever since the road started, has ever seen anything go wrong with the motors. DESCRIPTION OF THE RAILROA at Nantes. Motor-Car.—Two small engines are connected' so as to rotate the front axle of the car, a reversing lever being used to alter the cut-

Jan 1, 1891

By K. F. Clark

Some 30 years ago Stevenson (1940) underscored the fact that most of the world's molybdenite production came from the Cordillera that comprise the western part of North America, and that the northern extension of the Cordillera into British Columbia is not essentially dissimilar to the United States section. Therefore, in view of the successful development of molybdenite resources in the United States, he concluded that prospecting in the Canadian section f the Cordillera should be encouraged. However, as recently as seven years ago Schneider (1963) remarks that no large economic deposits have been brought into production in British Columbia, although one important property was being evaluated. World production f molybdenum ore was sporadic until 1900. Among the very early producing areas in North America were Arizona and New Mexico in the United States. World War I provided the stimulus that brought the Climax deposit into production, and in 1920 Questa, New Mexico followed, although the ore came from fissure vein deposits at that time. In the early part f this century high grade deposits in various parts f the world containing 5-20 percent MoS2 were exploited. In Canada most production during World War I came from Quebec and Ontario. With the build-up of world tension and the inception f hostilities in 1939, British demand was satisfied by United States producers (Schneider, 1963).

Jan 1, 1970

By F. Petersen, W. van Dyk, J. Bonsu, A. Isafiade

"This paper aims to demonstrate how a systemic approach can be applied to the analysis of the causes of accidents in South African mines. The accident analysis framework used was developed previously by the authors from the combination of the Mark III version of the Swiss Cheese model, Incident Cause Analysis Method (ICAM), the Nertney Wheel model, and safety management principles. Data on 91 accidents occurring from 2010 to 2012 at the site of a platinum mine in South Africa were used to populate the newly developed framework. The results obtained show that while routine violations (45% of all accidents analysed) were the most common form of human error, problems in the physical environment of workers were the most common workplace factor (39.6% of all accidents analysed). Furthermore, inadequate leadership was found to be the most common systemic factor responsible for accidents (51.6% of all accidents analysed). Some workplace factors were more commonly associated with particular unsafe acts than others, and some systemic factors were more associated with particular workplace factors than others. The outcome of this study demonstrates that systemic factors, rather than human errors and violations, are the chief causes of accidents in the mining sector. IntroductionThe mining industry is a very important sector of the South African national economy. A major factor threatening the sustainability of this industry is mining accidents, which frequently result in injuries or deaths, destruction of property, and pollution of the environment. In the past, mining accidents have led to the shutdown and threat of shutdown of mines (Ryan, 2008; Mail and Guardian, 2011). The country stands the risk of incurring significant losses if the mining industry continues to experience shutdowns. In 2012, the mining sector accounted for R262.7 billion (equivalent to US$32.83 billion) representing 8.3% of GDP directly, on a nominal basis (Chamber of Mines of South Africa, 2013).Mining safety is a global concern and has attracted significant international attention. This has precipitated various studies into different aspects of mining. Unfortunately, human error has been blamed for the majority of these accidents. A study by the US Bureau of Mines found that human error is the cause of almost 85% of all accidents (Patterson and Shappell, 2008). In Australia, it is the cause of two out of every three occupational accidents (Patterson and Shappell, 2008). Various mining companies maintain that they run efficient systems, and hence the behavioural problems of workers are to blame for most accidents. An understanding of accident causality could be a major step in the quest to reduce accidents. Only with a good understanding of the accident process can effective remedies can be designed."

Jan 1, 2017

By Anthony T. Iannacchione

This study, funded by the Appalachian Research Initiative for Environmental Science (ARIES), examines how mine layout, mining method, and geology interacted to allow water from the Grove No.1 mine pool to discharge into local surface waters. Federal and State regulations prohibit the discharge of acid or iron-producing waters from underground coal mines. Mining companies design barriers around their operations to prevent mine waters from discharging to the surface. The Grove No.1 represents one mine where these designs proved inadequate. Unique geologic conditions at the Grove No.1 mine pool, combined with retreat room-and-pillar mining, contributed to a discharge that required passive water treatment.

Jan 1, 2013

By D. R. Rice

Separation of valuable constituents from a complex mineral mixture was examined. Nitric acid leaching produced a solution containing copper, zinc, iron and a large proportion of silver. The residue contained antimony, lead, the remaining silver and elemental sulfur. A caustic sodium sulfide leach dissolved the antimony from the residue, producing an insoluble, high-grade silver-lead product and a filtrate for electrolytic recovery of antimony. The pH of the primary filtrate was raised, precipitating the iron and leaving a solution containing the copper, zinc and the soluble portion of the silver, which would be recovered by conventional means.

Jan 1, 1969

By C. R. Fast, George C. Howard

Laboratory and field testing of various squeeze cementing techniques and materials revealed that many improvements could be made in squeeze cementing operations. The use of a slow-pumping squeeze cementing procedure permitted the control of the quantity of cement displaced into a formation and aided in obtaining a high final squeeze pressure. Field testing indicated the desirability of obtaining high final squeeze pressures, the need for improved formation breakdown fluids, and the necessity of controlling the pressure differential during testing after a squeeze job. INTRODUCTION During the past few years, squeeze cementing operations have been investigated, both from the theoretical as well as the practical point of view, in an effort to arrive at some solution to the many and varied problems that arise with this type of operation. A review of well files indicated that in many instances, wells were being squeeze cemented four and five times before a satisfactory pressure buildup was obtained. There seemed to be considerable variation in opinion as to the proper method of squeeze cementing, as well as disagreement as to the proper breakdown agent, the quantity of cement that should be used, type retainer and length of WOC* time that was necessary. Consequently, it was deemed advisable to approach this problem theoretically, field testing each idea developed in hopes of eventually arriving at a squeeze cementing procedure that would give reasonable assurance of a successful job after one squeeze cementing operation. This investigation was. therefore, divided into two broad headings: (1) Preliminary studies, which include both theoretical and laboratory studies, and (2) Field investigations to determine the proper squeeze cementing methods. PRELIMINARY STUDIES Overburden Pressure Studies Squeeze cementing problems are so intimately related to the earth's overburden pressure that solutions to them are very difficult, if not impossible, without an understanding of the nature and magnitude of the overburden pressures encountered at the depths of producing wells. It was thus felt that the first approach to research on squeeze cementing should be made through a study of these pressures. Since there has been rather loose usage of a number of the terms related to overburden preasure by different writers, the terms to be subsequently used are defined here. Theoretical overburden pressure is the calculated pressure at any given depth exerted by the theoretical weight of overlying formations as calculated from the average rock density. Fluid displacement pressure is that pressure at which fluid can be injected into a formation after it has been broken down. It may be more or less than the theoretical overburden pressure. Formation breakdown pressure is that pressure at which a formation parts or breaks and is usually thought of as fluid displacement pressure plus rock strength. Breakdown agent is that fluid with which the formation is fractured. The first step in the study of the earth's overburden pressures involved a review of pertinent technical literature. The general opinion expressed was that the overburden pressure gradient of the earth's formations is roughly 1.0 psi per foot of depth, and that application of sufficient pressure to stratified formations. will cause them to part at or parallel to the bedding planes. The second step in the study of overburden pressures involved a study of available well data in an effort to obtain some definite information as to the actual values experienced in the field for the above mentioned terms. Data from 115 cement squeeze jobs in the Gulf Coast area and 46 cement squeeze jobs and acid jobs in the West Texas-New Mexico area were closely analyzed. The analysis of these data showed that the average formation breakdown

Jan 1, 1950

By O. C. Blade

This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1952 was made under a co-operative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. Analytical data are presented for 94 samples of aviation gasoline which include, for the first time in this series of reports, data on five samples of grade 108/135 aviation fuel. Data also are given for 34 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers? production in their laboratories and the results submitted to the Bureau of Mines for compilation. The products of 20 manufacturers of aviation gasolines and of 16 producers of aviation jet fuels are represented.

Jan 1, 1953

By R. H. Swallow, George Hess

Aerial photography was once a crude, uncertain tool. Today it is a precision mapping instrument which saves important time and money for strip mining and other industry. Aerial photography began in the boxkite days of aviation. The Army first used it for rough reconnaissance photographs. Then, in the early Twenties, industry began to use aerial photographs of their plants and facilities for advertising or annual reports. The quality of these pictures was not very good by today's standards, but this work began the development of better cameras, better lenses, better photographic techniques.

Jan 1, 1949

By R. L. Grayson, W. E. Wallace, T. Simonyi, J. C. Harrison

"Application of an SEM-based methodology suggests a reason for past contradictory results on the relationship between quartz and coal workers' pneumoconiosis (CWP). Results indicate that coal seams with the same bulk analysis of quartz may have different amounts of surface-availablequartz. Our research shows that the amounts of pure and surface-available quartz in a respirable dust vary directly with the rank of a coal seam, except in the case where rock materials are mined. The estimated amount of surface-available quartz therefore provides a measure of the quartz-related fibrogenic potential of a respirable dust.INTRODUCTIONFrom our previous work (Grayson, 1991), we have shown that the amount of pure quartz in a respirable coal mine dust sample appears to vary directly with the rank of the seam (using fixed carbon as the basis for comparison), except when a substantial rock parting, roof or floor are mined. Our other work (Wallace et al., 1989) showed that high-silica particles in a clay mine may generally be coated with clay, rendering the quartz core non-available for surface reaction in the lung. The combination of these findings led us to hypothesize that the coating phenomenon may indeed be present in coal mines as well, and that a rank relationship may be present regarding this phenomenon. Thus higher rank coal seams may have more surface-available quartz as well as more pure quartz particles in their respirable dusts. The scientific protocol for testing this hypothesis and the results obtained to date are discussed in this paper. Thus far, there is no reason to doubt that the relationship holds."

Mar 1, 1992

By M. Lahtinen, B. Saxén, M. Latva-Kokko

The conventional jarosite precipitation process with neutralization by zinc calcine is widely utilized in the zinc industry. However, it has a significant drawback of causing losses of valuable metals like zinc, lead and silver to the jarosite. This comes mainly from the content of these metals in the calcine used for neutralization. As the zinc plants today want to maximize metal recoveries and minimize the amount of residues, this matter has become more and more relevant for zinc producers. Outotec developed and patented in early 2000 an improved version of the jarosite precipitation process in which the need for neutralization can be minimized, thus the metal losses to the jarosite also can be minimized. At the same time, the iron content of the jarosite increases and the amount of produced jarosite is smaller. The main feature of this process is to start the precipitation from ferrous iron after having reduced all the iron by zinc concentrate in a separate step before jarosite precipitation. Iron is then oxidised back to the ferric form simultaneously with jarosite precipitation. By this method, the formation of sulphuric acid is only half that compared to the conventional method and the need for calcine for neutralization can be avoided. High mixing and oxygen dispersion capability are needed in this jarosite precipitation process. Such capabilities are found in the Outotec OKTOP® reactor series. High performance reactors are not only needed to generate high quality precipitates, but also to maximize oxygen utilization; i.e., to minimize operation costs. Outotec’s latest development in this area is the OKTOP® plant product in which not only the reactors, but also all the accessories are designed, manufactured and delivered by Outotec. One responsible supplier ensures efficient and fast delivery and can provide mechanical and performance guarantees for the entire plant unit.

Jan 1, 2016