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By David Norval

Water solidification of mattes, metals, alloys and certain slags with high metal entrainment has customarily not been practiced due to the belief that such processes are too dangerous and unproven in the Pyrometallurgical Industry. Slag granulation on the other hand is extensively applied, although in some cases crudely, with disastrous effects, as a result of not recognising the high heat capacities prevalent in slags. This paper will examine the most common air solidification processes and compare such processes with water solidification, mainly slag and matte granulation processes and design criteria for safe and reliable operation. Finally, purpose designed granulation and solidification processes will be discussed taking into account specific applications and the individual signatures of alloys and slags, emphasising that no slag, matte or alloy responds in similar fashion to a granulation practice.

Jan 1, 2006

By H. L. Paterson, R. R. Keays, M. J. Donaldson, D. J. Boyack, M. F. Smith, J. J. Gresham

"Albite-rich sedimentary rocks that contain abundant Fe sulphides occur in the lower portion of the ultramafic sequence at Kambalda and their broadly antipathetic relationship to most of the nickel orebodies is well documented. These sediments generally contain less than 0.1% Ni, but nickeliferous equivalents with 0.3 to >6% Ni occur locally in close spatial association with more typical volcanic peridotite-associated massive, matrix and disseminated ores. Nickeliferous sediments have been mined at several locations at Kambalda but, collectively, they constitute less than 2% of the total Kambalda nickel reserve. The nickeliferous sediments occur both on the ultramafic-footwall basalt contact and within the lower part of the ultramafic sequence, and are usually less than 5 m thick. They are commonly finely laminated rocks with a cherty appearance, composed essentially of layers of albite+quartz±amphibole, alternating with pyrrhotite+pentlandite±pyrite layers. Some contain a minor amount of carbon. The sediments are only of ore grade (> 1% Ni) immediately adjacent to massive Fe-Ni-Cu sulphides, which are interpreted as normal magmatic ores on the basis of geochemistry and the presence of distinctive ferrochromites. The nickel content of the sediments decreases to background levels (<0.1%) within about 20 m of the massive sulphides. In most locations the massive sulphides clearly have been emplaced tectonically within or adjacent to the sediments, which are commonly highly deformed. Typical nickeliferous sediments contain about 1% Ni, 0.1% Cu, 0.1% Zn, 400 ppb Pd, <0.2 ppb Ir and 10-200 ppb Au. They have lower Ni/Cu (average 10), higher S/Ni (average 6) and higher S/Se (average 11 200) than associated massive sulphides (average 40, 4.8 and 7400, respectively). The Pd/Ir ratio of the nickeliferous sediments (typically > 1000) contrasts markedly with that of associated massive sulphides (average ca 16).The high Pd/Ir values are similar to those which have been reported for hydrothermal Fe-Ni sulphides and barren sulphidic sediments of probable volcanic exhalative origin. They preclude a direct magmatic origin for the sulphides in the nickeliferous sediments, though S/Se and S isotope data indicate a magmatic source for the sulphur. The restriction of nickeliferous sediments to within about 20 m of normal magmatic sulphides and the lack of a widespread Ni dispersion halo suggest local redistribution of originally magmatic Ni. This probably occurred by diffusion and hydrothermal mobilization during deformation and amphibolite-facies metamorphism. Although not totally ruled out, a volcanic exhalative origin for the Ni seems unlikely."

Jan 1, 1984

By SME SME

NORTH AMERICAN TUNNELING 2024 PROCEEDINGS

Jun 23, 2024

By M. G. Fleming

The professional mineral engineer is an individual of personal integrity who has undergone rigorous intellectual instruction in the scientific disciplines fundamental to his vocation; he has learnt to apply these disciplines to the discovery, mining and treatment of mineral resources and, through practical training and experience, has acquired competence and judgment to fulfil his undertakings. In the course of this development he has recognised and accepted a threefold responsibility to society, to his employer and to his profession

Dec 1, 1971

By Micah Nehring, MEHMET KIZIL, Farzad Sotoudeh, Amin Mousavi, PETER KNIGHTS

Production scheduling in underground mines is one of the most important and complex processes in maximising the economic value of an operation over the life of the mine. Due to increasing energy, transportation, processing and smelting costs and reducing water availability, the extraction of ore deposits through underground operations has become more expensive and challenging. A potential productive and efficient solution to mitigate these issues is to integrate pre-concentration systems into the existing mining system to increase ore grades through a preliminary process of rejecting some waste before sending the ore to the energy intensive mineral processing plant. Further benefit of such systems includes the utilisation of the waste and low-grade material in backfilling of open stopes to reduce the transportation costs and surface environmental impact such as reduction of CO2 emissions and waste transportation. The objective of this paper is to present a new mathematical model to optimise the production schedule of underground metalliferous mining operations in the presence of a pre-concentration system. The proposed model optimises the production schedule and sequencing of stopes within a sublevel stoping operation. The results of this study illustrate the potential economic benefits of using a pre-concentration system prior to a mineral processing operation as a result of increased net present value.

Nov 16, 2023

By C. Haycocks

The problems caused by interaction in multi-horizon mining are world wide and are not limited to the coal industry. These problems will continue to increase as mining of new seams multiplies and replaces production from mined out horizons. Interaction problems are particularly evident in the Appalachian coal fields which contain many mineable, contiguously placed coal seams. Selection of the mining sequence of these seams, historically and currently, is based primarily on considerations of seam ownership, availability, and economics. Experience has shown, however, that mining any seam can seriously affect subsequent operations in coal seams both above and below the one being mined. This interaction effect is often detrimental to the recovery cost and safety of mining the subsequent seams. Designing to avoid or minimize interaction effects represents a major challenge to the modern coal mining industry and therefore is the focus of this research. In an effort to evaluate past interaction effects and provide guidelines for future mine design, interactive ground control problems were categorized into four areas. These are pillar load transfer, massive interseam shearing, subsidence and pressure arching effects. To facilitate research, each of these areas was studied separately although in reality these subdivisions are arbitrary and have considerable overlap.

Jan 1, 1983

By John W. Nebgen

This report contains findings from a U.S. Bureau of Mines study concerning the inhibition of acid mine drainage formation from underground coal mines. A series of experiments was performed in which three different pyritic materials (wastes from coal production plants) were evaluated using several candidate inhibiting agents. Data obtained from the inhibitor-treated pyrites were compared with data from control experiments in which untreated pyritic wastes were used. The experiments were conducted by placing treated and untreated pyrite in columns, passing moist air through the columns to promote oxidation of pyrite, and washing the columns weekly to collect oxidation products for analysis. Experimental results indicate that quantities of acid mine drainage can be substantially reduced if soluble iron III (ferric) ion is controlled. The best inhibitors are neutral or alkaline siliceous materials such as fly ash, blast furnace slag, portland cement, and cement kiln dust. These materials appear to insolubilize iron III species to make them unavailable for reaction with pyrite. The data strongly suggest that the soluble ferric ion aqueous is a key oxidant for pyrite to produce acid mine drainage. The role of aqueous ferric ion as an oxidizing agent is substantiated further by data obtained using metallic iron (nails) as an inhibitor. The iron nails tended to keep the soluble iron in the iron 11 (ferrous) state. Experimental results indicate that sulfate and acidity levels are reduced when pyrite is in contact with the metallic iron.

Jan 1, 1979

This report presents the results of a study of mill tailings disposal practices and potential tailings dam stability problems. Recognizing the long period of time that would be required to develop the technology and practices necessary to significantly improve refuse disposal safety, the Bureau initiated this research effort as a first step in that development. Volume 1 includes a summary of conclusions and recommendations resulting from the overall research effort; discussions of disposal systems and methods, geology, seismicity, hydrology, and materials characteristics; evaluations of investigational techniques; discussions of usable interim generalized investigational, analytical and inspection procedures; discussion of general principles and presentation of a tailings technology manual outline; and discussion of needed future research am recommended programs.

Jan 1, 1974

By W. P. Yana, J. B. Littlefield

"INTRODUCTION AND OBJECT OF EXPERIMENTAn explosion in and rupture of a gas-tight switch box on an electric loader in a mine located near Pittsburgh indicated that the cause was an internally generated inflammable gas-air mixture. This led to the suspicion that moisture condensation or ""other unusual conditions might have caused a spark or are across the surface of the material and that the heat may have created a carbonized path across the synthetic plastic base which would then conduct a large current with the generation of considerable heat and thermal decomposition of the base materials base in the box which exploded gave every indication that this series of events had taken place, and accordingly it was desired to determine what explosive gases such a decomposition of these insulating materials would produce.ACKNOWNLEDGMENTSThe desirability of making this investigation was suggested to the authors by L. O. Ilsley, supervising engineer, electrical section, Bureau of Mines, to whom the occurrence of an explosion in a switch box had been reported. The writers also acknowledge with thanks the assistance of L. B. Berger, chief scientific aide, health laboratory section, Bureau of Mines, in checking the calculations in the tables. DESCRIPTION OF MATERIAL INVESTIGATEDThe ten materials used in the tests, identified by letters A to J inclusive, are described in a succeeding list of materials. All the materials except I had a phenolic odor, especially when freshly cut."

Dec 1, 1932

By Robert L. Lagace

[Suuple Iheorctrccil models are I&apos;M lllolalcd to cltaraclerl/c medium frequency (MF) radio vase pi opaiation in undcrgiounli room arid pillar coal mines fur the purpose of predleiln the most lavolable operating fIegtucncics,md nr,ixunum communic;IIIoil ranges for pottahIe rldu)s with I top antennas. I or conductul IrCC areas, at hree layer propaeaIion IltodcI wit II a Iiallsmissloil IIIIi- lhlllllIIal&apos;u11 lot the plupa!edti ii unlstallt Iris been dcvcloped ;md verified experimentally. 1 lie mode u1 propaCaUetl lakes Ills form of i parallel plane (0,t)) TIM lransnussu)nhne 1% PC of mode with the electric held vertical and the magnetic held hoti/cntal t itliin a planar coal scam in which the tunnels Can he ignored and which 1s hounded above and below hp richer conductivity rock. 1lie model lilt the data best river the 200 io 1000 kH/ frequency hand and exhibits a rc;;lon of optlnrul1l Pelffelntance, with respect Io maxnluiulg radio Communication range, between 300 and 100 klf/. Maximum cunununlcatrorl ranges are sliongls dependent oil the sigiial alleilliatroil sale, ant) Illelclulc on the electrical conductivltles of the coal seam and surrounding ruck. These ranges v;ny tutu about ,,5 Io 100 nleleis Ill a high Iuss scam such as the Ilelllit No. fl to about .100 to 400 meters in a low loss seam such as the Pittsburgh foil portable intrinsically safe radios. The ieslllls die haled on the comparison oftheorc&apos; and experiment for eleven n n. ill sesen coal seams. V OT ate is dice: a conductor such as a power Cable, is present a model has been developed for the coupling of loop antennas to a low loss Coaxial TEM ti;u?smisslon line mode in which the cable acts as the inner conducl,lr and the rock above and below acts as the outer conductor. The electuc and md&apos; nctic Itelds for till` (node are apprlixitllatcly transverse to the cahlC and fall oil expontially with distance in the transverse plane. The principle of reciprocity is used to simplify the analysis. More expelitnental data arc needed to help resolve discrepancies between the theory and the limited data available to date.]

Jan 1, 1980

By S. D. Dladla, S. Ramsamy

The majority of the tailings dam operations in South Africa will be required to comply with the new Global Industry Standard on Tailings Management (GISTM) within the next one to three years, depending on the dam classification and the requirements of the respective investors and insurers. With up to 72 auditable requirements, the implementation of the Standard needs careful planning and prioritization. This paper focuses on the practical steps to GISTM compliance for tailings facilities in operation in South Africa. The discussions are based on current practices, South African regulations, and industry standards requirements. The possible changes in dam classifications and the associated requirements are presented.

Jun 2, 2022

By Thomas Fraser

"INTRODUCTION The Santa River Valley of northern Peru contains extensive deposits of a good-grade anthracite that offer one of the most accessible sources of solid-fuel supply for South America. This region is served by the narrow-gage railroad of the Corporation Peruana del Santa, which taps the coal fields along the Chuquicara River and terminates at the port of Chimbote, where facilities have been provided for loading coal into ocean-going vessels.This Government-sponsored corporation is prosecuting a vigorous program of development in this region, envisaging an intensively industrialized area around Chimbot Bay, fueled and powered by the anthracite of the upper valley and a hydroelectric generating plant now being constructed in the Cahn del Fate, where the Santa River has cut through the coastal range of the Andes.This development also includes the construction of extensive irrigation works to greatly expand agricultural production in the valley and thus estab¬lish the basis for a prosperous, well-balanced, industrial and agricultural community. It is hardly necessary to point out the importance of the local anthracite-mining industry to this general plan.At the invitation of the Peruvian Government, through the agency of David Dasso, chairman of Corpoacion Peruana del Santa, a technical mission was sent to Peru in March, April, and May 1945 to examine these coals and assist the corporation in promoting preparation of the coal for most effective use in the contemplated expansion of industry and trade."

Feb 1, 1948

By M. F. Boos

The Portland beryl-mica district, Middlesex County, Conn., comprises three deposits investigated by the Bureau of Mines in 1943. The Gotta-Walden deposit is in a pegmatite dike 4 to 20 feet thick, which cuts gneiss and schist. In general, the hanging wall is rich in mica and beryl with some feldspar, quartz, and garnet. The central core is usually high in quartz and feldspar, with relatively little mica and beryl. The footwall comprises quartz and feldspar, with varying amounts of mica and some beryl. The beryl crystals range in color from green to almost golden and have a maximum diameter of inches. Results of surface trenches indicate a beryl content of 0.81 percent for the pegmatite. A small production of beryl, feldspar, and scrap mica has been made from the deposit.

Jan 1, 1949

By Northcutt Ely

This volume summarizes mining and petroleum legislation in 30 jurisdictions of the Western Hemisphere. Within these jurisdictions, primary attention is given to requirements that must be met in each country for acquisition of rights to permit development of mineral resources. Coverage includes: First, identification of the controlling laws or statutes governing minerals acquisition and reference to the administrative authority; second, analysis of the laws governing mines and quarries and their products; and third, analysis of laws applicable to natural gas, petroleum, and related materials. Where pertinent, sections dealing with historical background or administration have been added. In countries where minerals are subject to control of States or Provinces, those areas are considered separately from the central government.

Jan 1, 1970

By Ron Galisky

Generalmente, las empresas mineras deben decidir si reemplazan los equipos anteriores por unos nuevos o continuan con los mismos . Los criterios se basan en el nivel de deterioro, cambios tecnológios, demandas medioambientales, o cambios de requerimientos. En ese sentido, el presente texto describe la metodología adecuada para la gestión de cambios de equipos a través de la teoría clásica del CAE donde se abordan tales problemas. Así también se plantea el uso del modelo CRU Strategies. La metodología ayuda en la planificación y gestión operativa y en los presupuestos de inversión anuales típicos en la industria.

Mar 1, 2012

"To prevent the propagation of mine explosions, the Bureau of Mines recommends:1. That all coal and lignite mines, except anthracite mines shall be rock dusted.2. That rock dust shall be distributed upon top, bottom, and sides of all underground openings of every description, to within. at least 4o feet of all working faces and the areas not rock dusted shall be kept wet.3. That the rock dust shall be maintained in, such quantity that the incombustible material in representative samples of dust collected shall not be less than 65 percent. Where methane gas is present in the ventilating current, the minimum percentage of incombustible matter in the mine dust shall be increased 1 percent for each 0.1 percent of methane.4. That when the rock dust in any area becomes caked so thatit cannot be dispersed readily as a cloud in the air, that part of the mine shall be redusted immediately.5. That the dust to be used shall not contain more than 5 percent of combustible matter nor. more than 25 percent of quartz or free silica; all of the dust shall pass through a sieve having 20 meshes per linear inch and 60 percent or more shall pass through a sieve having 200 meshes per linear inch; the dust shall not absorb moisture from the air to such an extent as to cake and destroy its effectiveness as a dry dust.6. That rock-dust barriers shall not be regarded as a substitute for generalized rock dusting.Research and experience have shown that maintenance of an adequate percentage of rock dust in all underground openings, whether gassy or not, of bituminous and subbituminous coal and lignite mines (anthracite dust does not propagate explosions) is the best means of preventing coal dust explosions. In rare instances where all fine coal particles on the floor, ribs, roof, and timbers are in a muddy condition continuously rock dusting is unnecessary.The term ""underground openings"" refers to all unsealed openings whether they contain track or not, and includes rooms, entries, crosscuts, breakthroughs, rock tunnels, slopes, haulageways, airways, and travelingways. The sealing of unused or abandoned parts of a mine in accordance with Mine Safety Board Decision avoids the necessity of rock-dusting the sealed-off openings.The kind of rock dust to be used should have the approval of the State Mine Inspection Service. Pure limestone or pare dolomite produces the best rock dust, as these dusts have low silica content, little tendency to cake, and a light color that aids illumination. To reduce tendency to cake it is preferable that not more than 75 percent of the dust pass the 200-mesh sieve. All sieve sizes are those of the Tyler screen scale. If the mine personnel is repeatedly exposed to breathing high concentrations of the dust, the percentage of free and combined silica should be as low as possible, preferably less than 5 percent. Persons engaged in the application of rock dust should wear approved dust respirators as listed in Bureau of Mines Information Circular 7030 or revisions thereof."

Mar 1, 1940

By Theodore R. Jolley

The estimated recoverable reserves in the area in the vicinity of Eska 2 mine are, 699,300 tons in the Chapin and Emery bas of the Maitland group. Those recoverable reserves are in the area between the Eska fault zone and Jonesville fault and extend down dip from the outcrops. No reserves were developed by the Eska 2 entry or by drill hole 14-16 in the Eska fault zone. The small quantity of reserves in the vicinity of the Eska 2 mine is insufficient to justify development of a now, modern .nine in this area. The estimated recoverable reserves in the area east of aka Creek are 974,500 tons in the Eska, Shaw, and Martin beds of the Eska group. Most of those reserves occur in the south limb of the syncline. It will be necessary to practice subjacent mining methods to recover these reserves in the Eska group. The Eska bed developed by the diamond drilling in this area comprises coal end few thin partings. The Shaw and Martin beds comprise two bunches of coal separated by partings, and the product from full-bed mining will require thorough preparation.

Jan 1, 1952

By José Arango Ortiz

Uno de los objetivos importantes de las operaciones hidrometalúrgicas en la mina Cerro Verde, es definir el tamaño adecuado para obtener recuperaciones de cobre mayores. En ese sentido, el presente texto plantea un estudio teórico que determine la granulometría más óptima para la lixiviación del cobre, especialmente en aquellos sulfuros secundarios de lixivación ácido férrica. Asimismo, incluye una serie de aplicaciones prácticas qe ayudarán al diseño de proyectos metalúrgicos.

Apr 1, 1991

Welina mai to the 40th Underwater Mining Institute, UMI 2011 - Marine Minerals: Recent Innovations in Technology. Since the first conference in Milwaukee, Wisconsin in 1970, the UMI Founder Professor Robby Moore always insisted on actively seeking the participation of industry, academia, and government. History has proven the wisdom of this approach, which is probably the key to its survival for so many years. The UMI is very much influenced by the cyclical pressures of the minerals commodity markets. When minerals demand and prices are rising rapidly, industrial participation in the Institute dominates the agenda, and participants share optimistic and aggressive views of the commercial prospects of the day. When metals prices are falling and world economies lethargic, academic experts continue to provide guidance and breakthroughs in the concepts and practices of exploration, technology, and environmental protection. Throughout the ups and downs, government participants provide a stabilizing force with conservative and environmentally sensitive policy statements, patient development efforts with long-term objectives, authoritative resource assessments and, sometimes, much needed regulatory clarity.

Jan 1, 2011

By J. K. Whyatt

This report describes a microcomputer-based instrumentation system for structural monitoring of the circular, concrete-lined Silver Shaft in northern Idaho, The 1-ft-thick concrete lining and surrounding rock mass were instrumented with a total of 12 multiple-point borehole extensometers, 16 pressure cells, 22 concrete embedment strain gauges, and 12 thermistors. The instruments were distributed among four test sites and installed immediately above the shaft bottom during sinking at the 2,414, 4,063, 5,191, and 5,955 levels. Limited access to the instruments prompted the development of a microcomputer-based remote data acquisition system that could be operated from the surface. The system scanned the instruments on a programmed schedule, printed out reduced data, and stored the data for plotting and recall. Data acquisition from off-site and uploading of data to mainframe computers were accomplished by the addition of modems to the basic system. The system is suitable for use in monitoring the structural behavior of any deep mine opening, especially in harsh operating environments and where access is limited.

Jan 1, 1986