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THE nature of the ore deposit of the Broken Hill line of lode is such that it can be broadly divided into two the calcitic and siliceous ore bodies. The principal minerals occurring in these ores are: Galena, sphalerite, pyrite, arsenopyrite, chalcopyrite, pyrrhotite, calcite, rhodonite, garnets, feldspar, fluospar, quartz.Whilst these minerals persist in both classes of ore, the following typical analyses of Broken Hill South Limited ore bodies will give some indication of the disposition with regard to each:

Jan 1, 1928

Rb-Sr measurements on total-rock samples of granitic rocks from the Mount Isa region have confirmed the existence of two periods of granite-forming activity. The Kalkadoon Granite, together with the Ewen Granite and possibly an older phase of the Sybella Granite, has been shown to belong to the earlier age-group at 1760 m.y.; the Wimberu Granite and a pegmatite associated with the Sybella Granite have been dated at 1540 m.y. The initial Sr ratio suggests that the Wimberu Granite may be new material of deep-seated origin.Further Rb-Sr measurements have confirmed previously-reported K-Ar results upon biotites from these rocks, whilst showing that, in this metamorphic terrain, biotites have lost varying amounts of radiogenic Sr and Ar, and therefore yield ages which are younger than the true age of the second event.

Jan 1, 1966

By T Hughes

The Gekko InLine Pressure Jig (IPJ) was unleashed on the World gravity separation market in 1996 and has since sold over 150 units in applications including tin, diamonds, silver, coal, garnet and gold. During the past twelve years the knowledgebase of the best applications and capabilities of the IPJ has greatly increased. Improvements to the original IPJ design have included engineered ceramic ragging in specific gravities from 1.6 to 5.0, full automation and improved designs of feed presentation and tailings and concentrate handling systems. The IPJ has been found to be able to handle a wide feed size range and recover mineral at liberation size without significant addition of water to the mass balance. Test work carried out during full-scale operation of the IPJ has shown the IPJ can recover diamonds down to 0.5 mm, sulfides down to 0.3 mm and gold down to 0.1 mm which greatly expands its application in the mineral processing industry. A significant volume of data now supports the symbiotic benefits of an IPJ and flotation circuit combination to pre-concentrate an ore and minimise downstream processing requirements.

Jan 1, 2008

By John R. Sturgul, Elizabeth Yost

The number of Native Americans presently working as mining engineers is extremely low-perhaps three in the entire US. At the New Mexico Institute of Mining and Technology, it was felt that introducing high ability students to mining engineering at the high school level would encourage more to consider mining engineering as a career. New Mexico Tech, in Socorro, NM, has initiated a continuing summer college program for Native American high school students. The program, which began in the summer of 1980, is designed to introduce participants to college life, enrich their high school curricula, and expose them to the problems and challenges of a career in mining and related engineering fields. Students From reservations throughout New Mexico with a demonstrated aptitude for science and mathematics were encouraged to apply for admission. Preference was given to high school sophomores and juniors since it is hoped that students will want to return for a second year before graduating from high school and beginning university studies. The program seeks to impress upon the students the need fir Native Americans in the fields of seience and mineral engineering.

Jan 7, 1981

By R. L. Virta

Four companies ? H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co., and Unimin Corp. ? mined ball clay in four states in 2013. On the basis of preliminary data, production was 1 Mt (1.1 million st) with an estimated value of $47 million. Production increased by 3 percent in tonnage from 973 kt (1.1 million st) with a value of $45.1 million in 2012. Tennessee was the leading producer accounting for 64 percent of domestic production, followed by Texas, Mississippi and Kentucky. About 67 percent of total ball clay production was airfloat, 22 percent was crude or shredded and 11 percent was water-slurried.

By Ramona Prillhofer

Salt slag is a waste product produced by the recycling of aluminum. In most European countries (e.g. Austria, Germany) the landfill disposal of this waste is forbidden because the slag contains soluble salts and these represent a potential source of pollution to the surface and groundwater. Additionally, consisting metal and some compounds in the salt slag can react with water and resulting from this, noxious gases are generated. The recovery of useful materials from these wastes is accordingly both environmentally necessary and economically feasible. This study describes a complete recycling-process for the salt slag, which includes a leaching-cristallization-process to obtain the oxidic residue, a pyrometallurgical-step to clear the oxidic residue and finally an extensive characterization of the achieved products. Due to the increasing price of raw materials, the utilization of the oxidic residue into commercial products has been investigated and application possibilities will be discussed.

Jan 1, 2009

About 15 per cent of total electricity (400 MkW) was generated by nuclear power plants in the world (2009) and about 36 000 tons of uranium has been mined in uranium mines annually. Radioactive waste material is produced from uranium mines and nuclear power plants. The wastes must be disposed or stored safely for long-term. If they leak and/or move from disposal or storage sites due to air/groundwater flow, then a serious environmental pollution can occur. Hence, multi-layer system has been proposed and employed in order to seal off these radioactive waste materials from biosphere. Basically, bentonite is now used for establishing absorbing and sealing layers in this system. However, the amount of high quality betonite is very limited and in some cases it is hard to be obtained.On the other hand, a great deal of refuse from coal burning plants is produced every year and the amount of it is expected to be higher each year, especially in developing countries. More than half of flyash is utilised and the remaining is disposed at the disposal sites. However, the life of the disposal site is limited and it is diff cult to find a new disposal site. It is requested that the percentage of the utilisation of the flyash be increased in every field.From the above two points of view, a flyash-based barrier layer/cover system is considered in this research and this paper discusses the applicability of flyash as a content of barrier layer/cover material based on the results of a series of laboratory tests.

Dec 6, 2010

The author summarizes and extends the relevant results of papers previously published by various authors and presents these results in chart form. The charts are used to demonstrate the theory on a hypothetical mine.INTRODUCTIONRecently a series of articles have dealt with leakage in a mine ventilation system and the problem of its reduction.Theories were developed by Peascod and Keane (1955) for the combined effect of flow in the airways and leakage through the porous barrier between the intake and return of an ideal mine. Later Keane and Peascoa. (1956) extended these ideas to the use of an underground booster fan in increasing the face ventilation and showed how to determine the water gauge and location of the most efficient underground fan.These articles were based on the assumption that Atkin:son's formula:P = R Q2 (1)gave the relation between the pressure drop P lb'/sq. ft., the quantity, Q kilocusecs, flowing in the mine airways and the total resistance, R Atkinsons, to air flow offered by the mine roadway. An Atkinson is defined as a resistance such that 1 kilocusec of air flows due to a pressure drop of 1Ib.jsq. ft. However for conditions prevailing in most mines a more :appropriate relation is that postulated by Reynolds and others (Lamb, 1953) :P=R Qn (2)where n has some value slightly less than 2. It should be noted that Atkinsons may not be used as units when n is not equal to 2.

Jan 1, 1958

By David R. Jessey

This volume contains the detailed mine site reports written by the WAPORA, Inc. and KETRON, Inc. staffs. It is a companion Appendix Volume to Control of Water Pollution from Surface Mining Operations. Copies of this report are maintained on Open File at the U.S. Bureau of Mines Research Center, Spokane, Washington.

Jan 1, 1981

By N. M. Skarbøvig

Safety nets have been used selectively in several South African mines over the years. Recently, however, an increased emphasis on mine safety has seen a resurgence of their utilization underground. This renewed interest has, however, also raised questions about the design and performance of these nets and their practical applications underground; these are the subjects of this paper. Generally, mine safety nets are used to protect personnel from falling rock in temporarily supported development ends, tunnels, ASGs and stopes. These diverse applications each require specific net designs, resulting in a wide product range. As a rule, however, mine safety nets need to carry specified static or dynamic loads with the least possible deformation. Because of the application-specific characteristics of mine safety nets, there is no South African national standard for them. Consequently, neither the SABS, nor the CSIR, performs standard tests on these components. In 2007, therefore, SIMRAC made available their Savuka facility for the testing of mine safety nets; the Savuka drop test became the accepted industry test standard for mine safety nets. From late 2007 to mid 2009, Norsenet, in collaboration with SRK Consulting, the designated operators of the site, conducted approximately 200 tests, which formed the core of Norsenet's database of safety net performance under various loading conditions. The test specimens comprised a wide range of net materials and config¬urations; the materials included: high density polyethylene, polypropylene, polyester, nylon, as well as a blend of polyester and polypropylene used primarily for reinforcement ropes. Net configurations encompassed the following parameters: net type, i.e., knotted nets or sewn nets; net strand type, i.e., braids, twines, or webbing; strand size; mesh size; mesh orientation, i.e., parallel or oblique to the net edge; net edge reinforcement, i.e., knotted, tied, with or without reinforcement ropes; internal reinforcement ropes, i.e., diagonal ropes and/or orthogonal ropes; as well as net attachment options, including loops and chainlinks. From the number of variables listed above, and the limited number of tests available, it can be appreciated that the findings of the test series required careful scrutiny. Nevertheless, principal performance factors clearly emerged: besides the obvious net mesh variables, such as net strand material, strand diameter and mesh size, it was the configuration of the reinforcement ropes and their attachment to the net panel which had the strongest influence on net performance. All the structural elements of a safety net need to work together to transfer the imposed load from the net panel, through the reinforcement ropes, to the net attachment points. In this load transference chain, the weakest link limits the strength of the structure. From this development work, Norsenet has gained valuable expertise to custom-design and manufacture nets to clients' specifications. The examples presented in the paper will also show the experience acquired in the installation of nets underground. Future work will include the establishment of a state-of-the-art net testing facility at Norsenet's factory in Vredenburg.. Keywords Mine safety net, safety net, protective device, mine safety, safety net design, safety net performance, safety net applications.

Jan 1, 2011

By G. M. Steed, A. O. Oyinloye

The deposit lies in amphibolite-facies biotite granite-gneisses of Proterozoic age, 4 km east of a major crustal break known as the Ifewara-Zungeru fault. Gold mineralisation is contained in a zone of quartz-carbonate (mainly calcite) veins and hydrothermally altered gneisses with associated small-scale intrusions along a steeply dipping second-order fault zone that roughly parallels the main fault. Gold is present mainly at grain boundaries between quartz and carbonate as discrete particles up to 100 micrometres in size, in general association with sparse, scattered pyrite, pyrrhotite and some base metal sulphides. Adjacent to the gold-bearing zone the granite-gneisses have been hydrothermally altered with minor volume increase, most notable enrichment being in K2O, S, Pb and Cu (and Au). High concentrations of Th, Y, Ce and Zr in the granite-gneisses imply derivation from S-type granites. It is likely that their high heat production capacity maintained the high temperatures needed to transport gold in the hydrothermal systems. It is most probable that the mineralisation dates from the Pan-African orogeny (650-450 Ma)

Apr 1, 1996

By E. S. Shedd

Amenability studies were conducted by the Federal Bureau of Mines on an electrooxidation technique for the extraction of mercury from cinnabar ores, particularly those that are too low in grade to be furnaced or retorted economically. Oxidation was accomplished by electrolysis of the ore while slurried with brine. Mercury was dissolved through the formation of the soluble tetrachloro mercury complex, HgC142-. Mercury extractions ranged from 90 to 98 percent in 4 to 6 hours of processing time when tests were made on eight different types of cinnabar ores containing from 0.7 to 18 pounds mercury per ton ore. Salt concentration was varied from 4 to 10 weight-percent depending on whether Pb02 anodes and iron cathodes were used or whether graphite was used for both electrodes. Power consumption ranged from 17 to 64 kilowatt-hours per ton of ore treated. Ninety-nine percent of the mercury was recovered from pregnant solutions by precipitation on an active metal such as zinc, followed by distillation of the resulting amalgam at 600° C.

Jan 1, 1975

By P. A. Rossouw, G. A. Fourie

Several attempts have been made over the latter half of the twentieth century to devise a system for the classification of underground mining methods. None of these are found to be totally successful. A revised classification is suggested with three main categories being identified by reference to fill requirements, steep stopes and stratified geological environments. Methods always needing lasting mass or structure fill include methods with timber-structured stopes and those with mass-filled (or cut-and-fill) stopes. Methods associated with steep stopes are subdivided into steep-stope-specific caving and steep-stope-specific non-caving (or self-supporting) methods. Methods not in the first two categories, often used in stratified geological situations, are not necessarily restricted to stratified environments and include caving as well as non-caving varieties. This category is further divided into room-and-pillar mining, longwall and shortwall coal mining and the type of open stoping found in gold or platinum reefs comprising overhand, underhand and breast-stoping variations

Dec 1, 1996

By Sangseom Jeong, Moonkyung Chung, Junyoung Ko

"Abstract The plugging effect of open-ended piles in sandy soil is analyzed by full-scale field test and plugging measurement. PLR (plug length ratio) measurement data from 144 field cases are analyzed with pile diameter. Based on the plugging measurements, PLR of open-ended piles which have above 1000mm diameter is predicted to be above 0.9. Through plugging measurements, a new empirical method is suggested for quantifying the plugging effect of open-ended piles. The proposed PLR equation is possible to predict the behavior of soil plug in the preliminary design stage. In addition, in order to investigate the behavior of the soil plug of open-ended pile, field load tests are performed on instrumented three piles driven into sand. It is obtained that the resistance components of open-ended pile are separated by double-walled pile system. It is found that inner shaft capacity is developed nearby pile tip. However, upper soil plug did not influence the inner shaft capacity. Also, it is found that all test piles are floating piles and unplugged condition because the sum of inner shaft capacity and outer shaft capacity is calculated about 58 to 76% of the ultimate bearing capacity.INTRODUCTIONIn Korea, a number of huge construction projects such as harbor terminals, offshore grand bridges, and lifeline systems are progress in urban and costal area. In these areas, steel pipe piles are frequently used to support high-rise buildings and heavy weight structures for ensuring structural safety rather than serviceability limit capacity. Also, steel pipe piles are frequently used in civil engineering structures because they have many advantages such as high-load bearing capacity, light weight and outstanding workability. The mega foundations of grand bridges and high-rise buildings are required in geotechnical engineering. Large diameter driven piles are frequently used in several projects.Many specifications such as API, FHWA and AASHTO have been reported as a design guideline of plugging effect, however , the current design method for plugging effect of steel pipe piles are mainly based on the our knowledge derived from observation of the model test or the small diameter pile load test. Therefore, these specifications have limitation to apply the large diameter steel pipe piles.Much work has been done to study the plugging effect by many researchers. Yamahara (1964) reported that soil plug has been modeled as a thin disk element as shown in Figure 1, since the increment of radial strain of the soil plug can be neglected due to high rigidity of the pile compared to that of the soil plug. Klos and Tejchman (1977) reported that the end bearing capacity of open-ended piles was almost equal to that of a closed-ended pile when penetration depth of pile was above 15times the pile diameters by model tests. Paikowsky and Whitman(1990) reported fundamental studies on mechanism of plugging effect in sand. Paik et al. (2003) reported that empirical relations for plug load capacity, annulus load capacity, and shaft load capacity of open-ended piles are proposed based on the model pile tests. As discussed above, much work has been done in the area of plugging effect. But little work has been done to study the plugging effect by full scale field tests."

Jan 1, 2014

A short account is given of the theory and practice of determining the true U3O8 content of ore samples by the determination of the beta and gamma activities separately, using the method of Eichholz and his associates.It is shown that, despite the variation of sample activity without change in U3O8 content, the true U3O8 value can still be found.Thorium can be determined simultaneously if this element is also present.

Jan 1, 1957

By A. Barba, M. P. Gómez, F. Puertas, M. Palacios, M. F. Gazulla, S. Martínez-Ramírez, I. García-Díaz

"The present study explores the reactivity and burnability of cement raw mixes containing fired red or white ceramic tile wastes or combinations of the two as alternative raw materials. The results showed that the new raw mixes containing these wastes are technically viable. The reactivity and burnability of the new raw mixes have been evaluated; confirming very good results when the particle size of wastes was less than 90 µm. The chemical and mineralogical compositions of the new clinkers were comparable to clinker manufactured with conventional raw materials. The mix of red and white ceramic tile waste was found to perform as well or better than each type of waste separately, a promising indication that separation of the two would be unnecessary for these purposes.IntroductionPortland cement clinker production consumes large amounts of energy (850 kcal/kg clinker) and has a considerable environmental impact. This involves massive quarrying for raw materials (limestone, clay etc), as it takes 1.7 tonnes to produce one tonne of clinker, as well as the emission of greenhouse and other gases (NOx, SO2, CO2) into the atmosphere. Around 850 kg of CO2 are emitted per tonne of clinker produced.The cement industry is looking for solutions to these problems, to attain sustainability and comply with the Kyoto Protocol commitments [1,2]. For that reason, experimental ways are being explored to develop cements whose manufacture is less energy-intensive, less damaging to the surrounding environment and with lower tendency to emit polluting gas. One of the reach this objective is the use of industrial waste and by-products as alternative materials for cement manufacture. Such alternative materials may partially replace fuel [3,4], conventional raw materials [5-8] or clinker in the final composition of the cement [9]."

Jan 1, 2008

By P. M. Ambrose, C. Travis Anderson, Cresap Moss, R. S. Dean

"MANGANESE METALMethods of PreparationMethods of preparing the manganese metal that has been used in chemical and metallurgical investigations have passed through a cycle. Most of the investigations made before the turn of the century used Moissan's pyrophoric manganese. 5/ This material was made by electrolysis into a mercury cathode and distillation in vacuo. It was essentially a pure material, and investigations in which it was employed (with proper precautions against oxida¬tion) led to accurate results concerning the intrinsic behavior of metallic manganese.An early investigation of the properties of ""Manganese-by-Mercury"" was made by M. Guntz. 6/ He prepared manganese by electrolysis of a concentrated MnCl2 solution with a mercury cathode. The manganese amalgam was pressed through chamois and distilled in vacuo (2 to 3 cm. of mercury) at 200°0., slowly rising to 250°0. Guntz recognized especially the decreased reactivity of manganese with increased temperature of mercury distillation. The most careful and com¬prehensive study of manganese made by this method is that of Kuh 7/ whose work unfortunately was never published in an accessible journal.Royce and Kahlenberg 8/ studied the electrode potential of manganese made by this method."

Nov 1, 1939

By Li Jiuping, Zhong Gang, Chen Yong Zhang, I. Michael Gowring

The Liaoning Dahuofang Reservoir Water Transfer Project is an important development for the Department of Water Resources of Liaoning Province in northeastern China. The 85.3 km water conduit will transport water from the Hun River downstream of the Huanren Reservoir to the outlet on the Suzi River leading to the Dahuofang Reservoir. The additional water is required to sustain the growing cities of Fushun, Shen-yang, Liaoyang, Anshan, Panjin and Yingkou. The project is divided into seven contracts. Three TBM contracts comprise almost 75% of the work and the others are drill and shoot. The focus of this paper is about the creditable TBM performances achieved and some of the problems encountered by Chinese contractors; notably two having had no previous TBM experience.

Jan 1, 2007

By L. Frost

Physical Conditions Great Britain The physical conditions in the mines investigated in Great Britain are similar to those found in the mines of the Dominion Steel and Coal Corporation, with the important difference that many of the coal seams visited were interspersed by a large number of heavy faults, making the development of a continuous face operation difficult, and in many cases the life of a unit development was exceptionally short, adding to unit cost; but in spite of these difficulties, a great deal has been accomplished in the application of mechanical loading units in a number of the mines in the areas visited. The coal-bearing measures, as in Nova Scotia, consist of shales and sandstones, and in some sections mussel bands overlie the coal seams making roof conditions difficult'. In several mines, the main roof consisted of weak shale bind, being held by a coal roof of varying thickness. This shale bind had a tendency to flow when the coal roof was broken. The floor, in some cases where cutter loaders were operated successfully, consisted of weak, flaky shales with very little resistance and a tendency to disintegrate into powder when broken. The depth of cover under which these mines were operating varied from 250 feet to 2,340 feet, with an average of 1,700 feet. The coal seams varied in height from 3 feet to 8 feet 6 inches, and the gradients from level to 33 per cent. The seams vary in hardness, but all-with the exception of one seam, the 'Morrison Busty'- presented a cutting problem similar to that found in Nova Scotia. The structure and cleavage of the coal was well defined and uniform. Some of the seams visited were gassy, ?but the temperature of the workings generally was not in excess of 70°F.

Jan 1, 1948

By R Lastra, J. A. Finch

An artificial standard material has been developed and used to examine the robustness of some of the procedures for correcting stereological bias. Different mineral liberation distributions were constructed from the standard material. The particles were mounted, sectioned and the sectioning data measured with an electron microscope interfaced to an image analyser. Four correction procedures were used and the corrected and true liberation distributions compared. It was found that the large-sections correction provided a simple, uncorrupted correction. Hill's fast approximation performed well except in cases of narrow liberation distributions; the sectioning data appeared to support the assumption that the locked section and locked particle distributions are identical. Barbery's correction performed well in most cases, having difficulty only with the very irregular liberation distribution. The PARGEN correction was able to provide a good estimate of the true amount of free material, but had difficulty in predicting the locked particle distribution

Jun 21, 1905