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By Christopher B. Kapes

To reduce concentrate dewatering and drying costs, the Concentrator Division at Phelps Dodge Morenci, Inc. investigated available filtration technologies. Numerous methods were explored, including: drum, disk, belt, pressure, hyperbaric, and ceramic media filtration. An economic evaluation of the individual filtration technologies indicated the advantages of ceramic media filtration for Morenci concentrates. This paper discusses the technological development culminating in the first full scale application of ceramic media disk filters in North America. Low moisture contents are obtained at high production rates and greatly reduced operating costs.

Jan 1, 1994

By A. Basçetin

Equipment selection in mining engineering is one of the most important decisions that affects the mine design, production planning and economic parameters in open pit and underground mining. Mine planning engineers generally use their intuition and experiences in decision making. Mostly, linguistic variables (the weather is raining, soil is wet, etc.) come into question and decision-makers may not know how these variables are computed. Since the advent of the fuzzy set theory, these uncertainties are easily interpreted in the decision-making process. The development of computer technology and programming of colloquial language with expert systems have considerably reduced decision-makers? burden. This paper reviews the development of a computer programme software called EQS (EQuipment Selection) that automates equipment selection in mining engineering using fuzzy set theory. The EQS with an introduction of the concepts and theories of multiple attribute decision-making, the fuzzy set theory, and EQS applications to mining industry problems with case studies are presented

Jan 1, 2006

By Stone. Jon P.

INTRODUCTION Countries that are currently developing their mineral potential have unique information systems requirements to support these activities. The mining laws usually grant the State considerable authority over the process. In many instances, the mining laws give a government agency the responsibility for granting and controlling exploration permits and development concessions. This is the case in Costa Rica. The Direcion of Geologia, Minas, y Hidrocarburos (DGMH) of the Ministerio de Industria, Energia y Minas (MIEM) is responsible for the management and operation of the National Mining Register. This paper describes the results of two studies of the information system requirements to support the National Mining Registry as well as those supporting some of the other function of the DGMH. The first of the studies reviewed the situation before the installation of computer equipment. The second study evaluated the installed systems. BACKGROUND Historical Perspective Mining in Costa Rica is at present a relatively minor part of the economy. It consists primarily of industrial minerals and gold production. Gold production is largely by small-scale miners and may be more substantial than reported. There is considerable interest on the part of the Government in both having a better understanding of the existing mining industry and promoting future development. Mining law was first provided by the Ordinanza de Mineral (of 1830). This was replaced by the first Mining Code of 1953. Apparently, one of the first problems caused by the 1953 law was the granting of concessions which were not worked. A 1968 agreement with ALCOA also resulted in political conflict. The Government worked on a new Mining Code for many years and in 1982 the current Mining Code was enacted. Draft implementing regulations were prepared in April 1984. Mining Code of 1982 The Mining Code of 1982 addresses most aspects of mining in Costa Rica including the declaration that all mineral resources are to be the property of the State. The State may grant exploration permits and exploitation permits. The exploitation of hydrocarbons, radioactive minerals and certain water resources was reserved to the state. The DGMH was given authority to settle placer claim disputes, maintain a registry of exploration permits, and exploitation concessions. and generally supervise mining activity. Towards this, the Mining Code of 1982 includes rather detailed requirements for the processing of application for permits and concessions. Mining Code Application Requirements The following briefly describes the requirements to give the reader a feeling for the complexity of the process. Currently, over 1,000 active applications, exploration permits and exploitation concessions are being monitored under the process. The number remains relatively consistent in that the number of new applications is usually about the same as the applications that are put aside. The time and date of the filing must be certified by the DGMH. The application must include all the information specified in the Mining Code. If incomplete, DGMH must notify the applicant of the deficiencies or omissions and direct that the applicant correct the deficiencies or omissions within 8 business days (a single 30 business-day extension is allowable). If the applicant does not respond as directed, the application is deemed as not having been filed and the pertinent information is placed in the files. The DGMH must reject the application outright and direct it be placed in the files in the following cases: (a). If the new application covers the area of a previous permit or concession, either being processed or already granted.

Jan 1, 1987

By A. J. Fejes

The purpose of this Bureau of Mines report is to provide mining industry personnel and regulatory authorities with a subsidence-reference list and annotated bibliography that will aid them in locating subsidence information and in developing their own subsidence information sources. Over 700 references are listed in the Bureau's subsidence information center bibliography; approximately 600 of these references were obtained for assessment. Of these 600 references, 167 were selected to be rated, categorized, and annotated. All literature referenced in this report was published prior to 1984. Table 1 is a cross - referenced index that classifies and rates selected references with respect to specific keywords. References are rated not on quality of content but rather on applicability to given subject areas. Appendix A is an annotated bibliography of the references listed in table 1 and provides further information of each article to aid the user in selecting articles for specific areas of subsidence technology. Appendix B is a copy of the subsidence information center bibliography.

Jan 1, 1985

By C. M. Rule

Stirred milling using either horizontal or vertical mills has made a rapid entrance into PGM ore and tailings concentrator flow sheets. Currently there are in excess of 40 units installed in either mainstream, ?MIG? or intermediate concentrate regrind, ?UFG?, applications in PGM, primary ore treatment plants or in tailings scavenging and reclamation treatment plants. This represents a total of approximately 70 MW of installed fine grinding equipment. This paper outlines the reasons why the technology take-up has been rapid and illustrates the advantages of this technology over conventional milling. Keywords PGM, platinum group metals, UG2, Merensky, platreef, stirred milling, MIG?mainstream inert grinding, UFG?ultra fine grindingof intermediate flotation concentrates, IsaMill?, Metso SMD?, Deswik, ceremic grinding media, QEMSEM, MLA.

Jan 1, 2011

By G. Scamans, J. Lazaro-Nebreda, Z. Fan, J. B. Patel

"Melt quality is crucial for both continuous and shape casting of light alloys and in order to improve it, removal of excessive inclusions, accumulated impurities and unwanted gases becomes necessary. To address this problem, a new multi-purpose high shear liquid metal treatment technology, based on intensive melt shearing by a rotor/stator unit, has been developed. The device ensures achieving uniform temperature and chemical composition and an efficient dispersion of gas and solid phases in the melt with minimal disturbance of melt surface, and can be used, among other things, for de-gassing and de-ironing of Al-alloy melts. Efficient degassing is achieved by dispersing each argon bubble into many small ones, which significantly increases the overall surface area of the bubbles and the time they remain in the melt capturing hydrogen before reaching the surface. This allows using much lower inert gas flow and mixing times than conventional rotary degassing. When applied to Al-alloy scrap, with accumulated iron, the high shear melt treatment speeds up the nucleation and growth of primary Fe-rich intermetallic particles, allowing a faster removal rate. Therefore it reduces processing times, increasing recycling productivity, and facilitates full metal circulation of secondary Al-alloys.INTRODUCTION Aluminium and magnesium alloys are widely considered in various industrial sectors for the purpose of weight saving (Polmear, 1995). In particular, they are used in the automotive sector, where components are mostly manufactured by high pressure die casting (HPDC) because of its simplicity and relatively low cost, but efficiency and mechanical properties are quite low compared with other processes. To date, the main focus to overcome this problem has been for improving the HPDC machinery (Dahle, 2001) but little attention has been paid to the opportunities of controlling the nature and quality of the molten metal supplied to the die. In this way, liquid metal treatment, which involves a variety of physical and/or chemical processing methods to improve melt quality prior casting, is crucial for both continuous and shape casting products."

Jan 1, 2018

By R. B. Barlow, J. A. C. Fortescue

Originally developed for use in mineral exploration, regional geochemical mapping based on stream (and lake) sediment sampling is showing broader application in other areas of the earth sciences and in environmental science. The purpose of this paper is to focus attention on the role of regional geochemical mapping in relation to geological and environmental studies. This is achieved using a descriptive equation for the chemical composition of a stream-sediment sample and then relating it to the use of successive approximations in geochemical and environmental investigations. The procedure is further qualified with reference to time and process in the formation of regional geochemical patterns. Examples are included of studies based on stream sediments related to bedrock geology, surficial geology, ecology and man's effect on the geochemistry of the environment. The range of applications of regional geochemical mapping in earth and environmental studies is outlined and some conclusions drawn regarding the future development of geochemical mapping under Canadian conditions.

Jan 1, 1980

By L. C. St. Arnaud

"Open pit mines can produce large disturbances within regional hydrogeologic systems. The degree of disturbance and the consequences on the local environment depend on the size of the pit and on the physical setting of the mine. Comparisons and contrasts are presented for three Noranda base metal open pit mine sites.The Brunswick Mining and Smelting No 6 open pit has a surface area of 11 ha and a depth of 185 m. It is located within complexly deformed schists and meta-volcanic rocks. The massive sulphide and iron formations visible along the north and southwest walls of the pit generate acid drainage. Mining ceased in 1983, and the pit is presently being filled with waste rock and neutralized drainage water. Water balance calculations estimated a total fill up time of sixteen years. As the water level rises, leakage to groundwater could take place across a fault zone intersecting the pit.The Mattabi Mines F-Group pit has a surface area of approximately 3 ha and a depth of 50 m and is also set in meta-volcanic rocks and acid generating iron formations. Production at this site ceased in 1982, and the low pH pit water is neutralized and pumped into a nearby lake at least every five years. Major water inflows are from precipitation and groundwater. Groundwater mounds within adjacent high land surrounding the pit provide a natural hydraulic barrier to groundwater flow, except for the southeast side. As a consequence, the pit water elevation is being kept below the elevation of the nearby creek in which some of the pit water could drain.The Bell Copper open pit covers an area of 40 ha and is 270 m deep. With present ore reserves, the mine might be in operation until 1992. The geology around the pit consists of andesitic tufts, siltstones and shales, and the acid generation potential of the rock is relatively low. A recent hydrogeological study estimated fill up time by precipitation and groundwater to be in the order of 260 years.With increasingly more stringent requirements for mine closure, it is anticipated that more detailed hydrological and hydrogeological studies of open pits will be required to determine post-closure environmental impacts and the suitability of open pits for mine waste disposal."

Jan 1, 1990

By Pupazzoni P. D, Meissner D. C

Incorporating an iron ore pelletising plant, a MIDREX'"' Direct Reduction Plant, and a mini mill, the conversion of iron ore fines to high- quality steel slabs in Western Australia is among the lowest cost routes in the world. The cost and availability of iron ore and natural gas, government support, and proximity to the growing Southeast Asian market all contribute to the competitive position of the area. Owing to the lead-time required, this is an ideal time to develop a new project to supply semi-finished steel to Asia for rolling to a finished product. A project contracted now will start up in about three years, when the market should have recovered.

Jan 1, 1999

By E Heath, F McDermott, S Turner, P van Calsteren

U-Th isotope studies of recent volcanic rocks may be used to evaluate the depths and rates of melt generation beneath midocean ridges and ocean islands. Island arc rocks exhibit a similar range in Th isotopes to that seen in both MORB and om, but while those with high (230Th/232Th) tend to have excess 238U, many of those with low (230Th/232Th) are in isotope equilibrium. The excess 238U is attributed to the preferential mobilisation of U in hydrous fluids from the subducted slab within the last 100 000 years, whereas the low Th isotope ratios in the higher-K arcs are primarily due to the introduction of subducted sediment. Preliminary results from mineral separates from lavas on Soufriere on the island of St. Vincent indicate that some of the minerals crystallised up to 50 000 years prior to eruption.

Jan 1, 1995

By J. W. Jamieson, J. Escartin, A. Steinführer

Evidence of hydrothermal activity on two Mid-Atlantic Ridge oceanic core complexes (OCCs), at 13º30’N (the Semyenov 1 through 5 fields) and 13º20’N (the Irinovskoe field) (Fig. 1) were studied using CTD casts, dredges, TV-grabs and SP surveys during previous research cruises to these sites (Cherkashev et al., 2013, McLeod et al., 2009). In late 2013, the Semyenov and Irinovskoe fields were revisited, this time with an autonomous underwater vehicle (AUV) and a remotely-operated vehicle (ROV) during the ODEMAR (Oceanic Detachments at the Mid-Atlantic Ridge) cruise on the French research vessel "Pourqoui Pas ?". Here we present the first visual surveys and direct sampling of these vent sites. High-resolution (~2 m) bathymetry of the 13º30’N and 13º20’N OCCs and their associated vent fields was collected during 4 and 5 AUV dives, respectively, using the GEOMAR AUV "ABYSS" (Fig. 1). These surveys were flown between 70 m and 100 m above the seafloor, typically at a constant height to reduce vehicle movement. The AUV was equipped with Eh, turbidity, and temperature sensors in order to detect active hydrothermal venting. Over twenty ROV dives with the ROV "VICTOR 6000" allowed for the visual exploration of the OCCs and collection of 59 hydrothermal rock samples from the vent fields. As a result of these exploration activities, the first robust estimates of the size of the deposits, and the geologic controls on sulfide accumulation at these sites can be determined.

Sep 1, 2014

By W. J. Boone

Experimental determinations were made of vapor-liquid equilibria data for a helium-nitrogen-methane system. A mixture composition was chosen to approximate the crude helium to be produced Or conservation that will eventually be further refined to obtain pure helium. Although there are publications of studies of the vapor-liquid equilibria of helium-nitrogen, helium-methane, and nitrogen-methane binary systems, there is little indication of work done on the ternary system of helium-nitrogen-methane. The experimental data presented in this report supplement the information available for the binary systems. The equilibrium vapor-liquid data and equilibrium vaporization coefficients are presented in tabular form. Graphs are employed to show an extensive amount of the data.

Jan 1, 1963

By B. P. Watson

Crush pillars have been incorporated into a mechanized, low-profile trackless system at South Deep Gold Mine. These pillars had to be designed to fail near the face and to ensure that pillar failure is contained within the pillar, to avoid bursting and the risk of high loads being generated during a seismic event, respectively. PoweRite backfill bags were recommended to maintain the integrity of the pillars; except in the main access drives, where the sidewalls were to be supported on 5.6 mm diameter weldmesh and yielding anchors. The results of a trial site investigation exceeded expectations, showing a residual pillar strength of about 37 MPa for a newly formed pillar and 8 MPa for a pillar subjected to seismicity and a closure of more than 300 mm. The introduction of these pillars has improved the rock mass conditions because of the active nature of the support, compared to the previous passive backfill method. Importantly, the pillars have increased mining efficiencies and improved face availability. A potential cost saving to the mine of R140.9 million could be realized over a period of 10 years.

Jan 1, 2014

The development of a noise attenuated compressed air driven fan is described. The fan, which employs the jet reaction principle, possesses blade extension pieces which penetrate into an acoustically treated annular chamber. The dominant noise source, namely the air jets, is thereby partially suppressed. In addition, the increased moment arm of the jets leads to an improved propulsion effect which contributes to the improved aerodynamic performance of the unit.A typical measure of the improvement of this type of auxiliary mine ventilation unit is a 4 per cent increase in efficiency and a 10 dB (A) drop in sound level for a fan duty of 0·5 kPa and 1600 litre/s. This degree ofattenuation corresponds to at least halving the loudness level, a subjective noise measure.

Jan 1, 1973

By Joan T. May

Federal Bureau of Mines studies showed that some organic amine hydrochlorides can be used as dehydrating agents for producing anhydrous magnesium chloride from hydrates and brines. Laboratory-scale tests showed that double salts are formed by reacting 35 percent magnesium chloride brine or spray-dried magnesium chloride with pyridine hydrochloride. Heating decomposed these double salts to anhydrous magnesium chloride and recycle pyridine hydrochloride. Pyridine hydrochloride also chlorinated any magnesium oxide in the spray-dried magnesium chloride. The anhydrous magnesium chloride obtained by the method described contained less than 0.8 percent oxygen. More than 98 percent of the organic amine hydrochloride was recovered.

Jan 1, 1978

By Jonathan S. Kelly

Effective control of respirable dust is one of the most serious problems associated with longwall mining in the United States. This report describes the development and the underground evaluation of ventilated cutting drums, on a double ended ranging drum shearer. The ventilated drum uses high pressure (1,500 psi) water sprays to draw air (3,500 cfm) through 12 airmoving tubes mounted in the drum hub. The sprays draw dusty air from the face side of the drum, scrub the air, and discharge the clean air on the gob side of the drum against a deflector plate. During a three week underground evaluation, the cutting drums reduced shearer generated dust levels at the shearer operators position by 40%, at the shield operators downwind of the shearer by 55%, and at the tailgate by 55%. Cutting and loading performance of the drums were superior to the mine?s conventional drums. After the evaluation, the mine continued to use the ventilated drums to finish mining the panel. During this 3 month period, there were no mechanical or seal failures demonstrating excellent system reliability.

Jan 1, 1987

By David Young

This paper presents tunnel design considerations for the SR75/282 Transportation Corridor Project in Coronado, California. The project is managed by the City of Coronado in cooperation with Caltrans and the US Navy and may include a one-mile long twin-tunnel section with two options: a 36.5 foot diameter twin-bored tunnel or a twin cut-and-cover box. The alignment crosses the Coronado Fault, and design provisions were needed at the fault crossing to maintain life safety and prevent rapid inundation of the tunnel in the event of fault rupture. These provisions are discussed along with considerations related to liquefaction and ground shaking. The project is currently in the planning stage with construction to start around 2012.

Jan 1, 2008

By P. J. Doig

The LCLS project at SLAC will allow new insights into material properties, chemical reactions and biological processes. The project includes half a mile of new underground construction. Excavation in weathered rock is by NATM, using AM 50 roadheaders. Construction began in 2006 and is expected to be completed in 2008. This paper details the construction of the tunnels and cavern on the project.

Jan 1, 2008

By D Craw, K A. Hunter

Deposits of the metalloids arsenic and antimony occur in quartz veins of mesothermal hydrothermalsystems in the South Island as arsenopyrite (AsFeS) and stibnite (Sb2S3). Arsenopyrite and stibnite occur in natural exposures in gold-mining areas, and additional arsenopyrite and stibnite have been exposed to the atmosphere by mining activity. At present the drinking water limits for dissolved As and Sb are 10 ppb and 3 ppb respectively. Sampling and analysis techniques are critical to determination of metalloid concentrations at these low levels. Endeavour Inlet in the Marlborough Sounds is an historic mining area (late 19th Century) with elevated As and Sb in waters emanating from mineralised rocks. Waters running out of abandoned adits have concentrations of As and/or Sb up to ppm levels. Natural waters have high Sb and low As, and the As levels increase markedly where anthropogenic activity has exposed rock. Changes in Sb/As ratio could potentially be used to quantify the anthropogenic component of metalloid mobility on mine sites on the 100-year time scale.

Jan 1, 2002

By Benjamin Smith Lyman

PAGE I. ANCIENT HISTORY,........... 57 Accepted Fables ; Babylonian Mapping ; First Surveying. II. COMPASS,.............59 Chinese Invention; Marco Polo; First European Compasses ; Early Knowledge of Variation ; Plotting with the Compass ; Hanging-Com pass ; Supposed Gravitational Error ; Merit of the Compass. 111. Telescope,............63 Origin (Roger Bacon, Porta, Digges, Lippershey, Galileo) ; Improvements (Micrometer and Cross-Hairs, Rittenhouse's First Telescope, Platinum Cross-Wires, Telescopic Sights, Reflecting Telescope, Achromatic Lens, Kellner Lens in Erecting Telescope, Inverting Telescope). IV. Theodolite,.............81 Origin ; Derivation of the Name. V. TranBit,.............86 First Surveying Transit; Edmund Draper. VI. Instrument-Parts,..........89 Ramsdenl a Dividing Engine ; Fineness of Graduation ; Conical Gradua tions ; Full Vertical Circle ; Leveling-Screws ; Shifting Tripod-Heads ; Hoffman-Harden Tripod-Head ; Heller & Brightly's Improvements. VII. OTHER INSTRUMENTS AND APPLIANCES,......100 Sunflower; Plummet-Lamp; Chains and Tapes. VIII. SCOTT'S TACHYMETER,.........104 IX. Nomenclature and Classification,.......105 Names; Grouping. Surveyors are much indebted to Mr. Scott for so vigorously attacking the subject of the origin and history of mine-surveging instruments, the compass, the telescope, the transit and other apparatus. He is not afraid of the dark, nor yet foolishly bashful in broad daylight. He does not recoil from the obscurities of the earliest times and the most difficult historical points; and, with commendable public spirit, he makes his own invention known to his fellow-workers, and challenges their criticism. He has, moreover, elicited the praiseworthy emula-

Jan 1, 1902