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By Scott Ellenbecker

The formation in Newmont Mining?s Phoenix Mine near Battle Mountain, NV contains high levels of abrasive quartzite as well as gold, copper and silver. Newmont started mining operations at Phoenix (formerly Battle Mountain Gold) three years ago and the planners knew they were working with a challenging geological formation. But as it turned out, it was more challenging than anticipated. Mine manager Mark Evatz said, ?Anything that touches Phoenix rock wears fast. The rock fights back here.? To contend with the hard conditions, Newmont uses Atlas Copco?s Pit Viper 271 (PV-271) blasthole drill. Because of the hardness of the rock, drilling at Phoenix requires hammer drilling and the mine uses Atlas Copco TD65 hammers with 171 mm (6.75 in.) bits. The mine?s PV-271?s are outfitted with a single 41 m3/min (1450 cfm), 2.4 MPa (350 psi), oil-flooded air compressor. Phoenix has six Atlas Copco PV-271 drill rigs plus an Atlas Copco DML and a DM45 midrange blasthole rig. The mine?s goal is to keep 3.6 Mt (4 million st) of muck in inventory to stay ahead of the shovels and support needed operational flexibility (ore control related). Drilling efficiency has been a continuous point of improvement since operations began at the mine. The single-pass depth capability of 16.5 m (55 ft) on the PV-271 helped with that. Originally, the plans called for 6-m (20-ft) bench heights, supported by 7-m (23-ft) drill depths, and time spent moving from hole to hole was eating up productivity. Drilling on that plan resulted in drilling an average of 14 m/h (47 ft/hour). When depths were changed to 13-m (44-ft) drill depth, supporting blasting of 12-m (40-ft) benches, they were able to use the single pass capacity of the PV-271. Performance increased to more than 18 m/h (60-ft/hour) an hour. Although the drill depth change largely supported the improvement, other aspects of continuous improvement associated with improved knowledge of the Pit Viper drills helped as well.

Jan 1, 2009

By R. G. Gürtunca, J. A. Breslin

This paper briefly describes the progress in mine safety in the United States, with emphasis on recent events that have followed since the explosion at the Sago Mine in January 2006. Legislation following the mine accidents last year and areas of work carried out by the National Institute for Occupational Safety and Health (NIOSH) related to the accidents are discussed. American coal production in 2006 was 1,150 million short tons. Most of this coal is consumed domestically, with annual exports of coal about 50 million tons. One third of annual production is produced at surface mines and the rest from underground. This coal is produced by about 82,000 miners working at 1,400 coal mines. Major improvements in coal mine safety have been made in the US since the Federal Mine Safety and Health Act of 1977. The fatal injury rate in underground coal mines between 1977 and 2004 was reduced by 47.8% to 0.036. The annual number of fatalities dropped from 112 to 14 during that period. Likewise, the non-fatal days-lost injury rate was reduced by 42.6% from 10.87 to 6.24. The improvements in mine safety during this period can be seen in the graph of underground coal mine explosion fatalities and injuries from 1980 to present, which is shown in Figure 1. Between 1984 and 1993 (9 year period) there were 5 explosions and one major mine fire, for a total of 55 fatalities. Over the seven year period from 1993 to 1999 there were no fatalities from coal mine fires and explosions. However, in the six years since 2000 there have been 5 explosions and one fire, which have caused 37 fatalities. [ ]

By D Lichti

This paper presents recent advancements in the MillMapper software technology, developed and used for thickness gauging of liners of cylindrical grinding mills used for mineral comminution. MillMapper uses calibrated laser scanner data captured inside a mill to determine thickness at several million points on all liner surfaces with millimetre accuracy. The paper is structured as follows. First, a review of the technology and its numerous advantages over existing techniques and the value it adds to operations are presented. These are followed by discussion of recently-implemented innovations, including improved visualisation and inspection tools, automatic ball charge volume measurement and automatic mill liner volume/weight measurement. Results from its application at several sites in Australia are presented throughout.

Jan 1, 2007

The safety analysis of shaft-sinking operations included a review of accident reports from coal and metal-nonmetallic mine shaft-sinking projects in the United States, a review of foreign and domestic shaft laws, and discussions with shaft contractors and Federal mine inspectors. Accident data were studied to identify the most common and the most severe types of shaft accidents and to determine their immediate and contributing causes. Additional factors such as worker training and experience, equipment and sinking procedures, regulations and enforcement practices were also investigated to determine their impact on shaft safety. The results of the study are summarized in recommendations for improved training of shaft miners and clarification of Federal shaft-sinking regulations. A guide to assist mine inspectors in examining shaft-sinking projects is also included.

Jan 1, 1977

By R. Kanniganti

The primary problems of pillar design in seams subject to interaction are due not only to difficulties in predicting loading, but also to the often unsymmetrical nature of the stress fields. The effects of uneven stress fields on failure patterns within a pillar were studied wing a two dimensional finite element method. Lower seams, including ultra- close mining situations were evaluated considering conventional pillars. Pillar case study data for under mining were analyzed to determine if empirical trends in stable pillar sizing could be derived. Recommendations for multi-seam pillar design are made, based on anticipated loading conditions within a pressure bulb. Applications of the research results are demonstrated using case studies

Jan 1, 1995

By L. F. Elkins

In 1946 Littlefield, Gray and Godbold published a thorough geologic description of the West Edmond Hunton Lime reservoir, located in Central Oklahoma, and discussion of its early performance.l They stressed implications of the nature of the reservoir rock on performance to be expected with production both by natural means and by pressure maintenance with gas injection. The essence of their analysis was that presence of an extensive interconnected system of fractures and solution channels constituting about 10 percent of the total reservoir void space in otherwise very low permeability reservoir rock would result in severe channeling of naturally encroaching water or injected gas through the fractures with little or no benefit to ultimate recovery of oil. Considerations were in progress to unitize the reservoir for pressure maintenance by gas injection. Some other engineers involved in the project had considerably different opinions at the time regarding continuity of fractures and regarding effects of such fractures on performance. The field was unitized Oct. 1, 1947. Subsequently, pilot gas injection tests were conducted in four areas of the field; large scale waterflooding was conducted in two parts of the field in the Bois d'Arc or Upper Hunton; and pilot waterflooding was conducted in the Chimney Hill or Lower Hunton. Full scale water-flooding is now in progress in the Chimney Hill section where it is oil productive. The primary purpose of this paper is to divine some of the secrets of this reservoir through analysis of all aspects of its performance, with the hope that it will be of help to engineers and operators in developing and operating other low permeability fractured reservoirs. In part, this considers variance of actual performance from some widely used conventional reservoir engineering assumptions. For brevity, other aspects of unit operation and its benefits to the owners are not discussed. Oil and Gas in Place For unit participation, net pay in the Bois #Arc defined by the gross SP anomaly on electric logs totalled 2,100,000 acre-ft in the 30,000-acre reservoir. Development of West Edmond predated modem logging techniques that now would be used to determine "net" or "productive" pay. In Fig. 1 this log pick is compared with detailed core analysis and core descripfion by Littlefield et a1.l for one well identified as A on the index map in Fig. 2. Not all of the gross Bois #Arc section had oil staining, but all cores with measureable intergranular permeability were stained. (The committee selection of the Bois d'Arc SP interval also includes the Frisco section as identified from cores by Littlefield.) The Bois d'Arc is oil productive throughout the entire 600-ft monoclinal accumulation from the eastern upstructure erosional pinchout to the west-side oil-water contact. (See Littlefield et al.l and McGee and Jenkins for geologic detail.)

Jan 1, 1970

By D. R. Dollnar

At a mine in central PA, high horizontal stresses have caused long running roof falls resulting in hazardous conditions for the miners and the premature abandonment of panels. Because of these conditions, the mine requested assistance of the National Institute for Occupational Safety and Health (NIOSH) in utilizing the 'advance and relieve method to mitigate the affects of horizontal stress on the mine roof. "Advance and relieve" mining involves the removal of a pillar or a portion of a pillar during development, thereby creating a cave along one side of the panel. Following cave development, the horizontal stress is relieved over the workings adjacent to the cave in the active panel. The mine has used this system in three panels with a significant reduction in stress damage and no large roof falls.

Jan 1, 2002

Mineral Processing Education in China

Sep 13, 2010

By Charlie Wyche

In 1980, gold, silver, and pit and quarry construction materials were the principal minerals produced in the Dominion of Fiji. The combined value of these minerals totaled some $7.2 million,2 over 85% of all mineral production, Production of cement, sand and gravel, and quarry products continued to increase, but gold and silver production from Fiji's only operating mine declined slightly from the previous year's level. Mineral exploration has been carried out by U.S., Australian, British, Canadian, West German, and South African companies since the early 1960's, and a high level of activity was maintained throughout 1980. At the end of 1980, some 40 mineral prospecting licenses covering over 4,300 square kilometers were in force, and 19 applications were under consideration by the Mineral Resources Department. Total expenditures by mining companies on land base projects exceeded $6 million in 1980.

Jan 1, 1982

By Charles Zdazinsky

Over-break is undesirable in underground civil construction because it excessively damages rock along the perimeter of the tunnel, which directly influences the cycle times of advancement. A quicker cycle time for each process is required to optimize the operation and therefore minimizing over-break is essential for operational success.

Jan 1, 2015

Situated in the Greymouth Coalfield, the Mt Davy Block contains a significant resource of high quality bituminous coal suitable for use in metallurgical coking coal blends. The coal, which is all low sulphur, is seen as a complementary deposit to export coking coal at Stockton Mine.   Previous drilling by State Coal Mines (1948 - 1953) and Japanese interests (1970's) have been supplemented by Coal New Zealand drilling (1992 - 1993) and surface mapping. A mining feasibility study was completed in late 1993 and approval gained for the driveage of an exploratory tunnel to the target seam.   Following construction of surface facilities, tunnel driveage on a 1:5 decline commenced from Rewanui in May 1995 and to date about half the required length has been driven. When the seam is intersected a comprehensive geotechnical testing programme will be undertaken to assess the in-situ mining conditions. It is expected that the results will confirm the assumptions made in the feasibility study.   The Mt Davy Mine, at depths of 500 - 700 metres, will be the deepest underground coal mine ever inNew Zealand and in-situ stresses (orientation and magnitude) will be important considerations for mining engineering. The coal has a high gas content and suitable techniques for gas control and prevention/mitigation of coal outbursts will be necessary.   Mine development is scheduled to commence in mid 1998 and an annual production level of 500 000 tonnes is forecast. The coal seams will be developed by continuous miner and coal extraction will be by hydraulic monitor. Coal will be pumped to the surface and from Rewanui transported five kilometres to Dunollie either by truck or slurry pipeline. At Dunollie a coal dewatering plant, coal stockpile and rail loadout will be constructed.

Jan 1, 1996

By Ray Brandon

The recent introduction of polymer geogrids for ground control purposes in underground mines allows mine operators more flexibility in choosing improved products for several applications. This is evidenced most clearly in longwall recovery operations. Since November, 1994, many mine operators have chosen Fortrac geogrid assemblies for the purpose of securing longwall recovery areas prior to shield removal. Fortrac is a lightweight, strong, and flexible polyester geogrid available in many strengths. Utilizing the "diamond" seaming method, different strengths of Fortrac geogrids are easily fastened together so stronger geogrids may be placed in the most critical areas and lighter geogrids in less critical areas.

Jan 1, 1996

This publication summarizes, for potential contractors and other interested parties, the research, development, and demonstration contract projects programed by the Bureau of Mines for fiscal year 1979 (October 1, 1978-September 30, 1979) under its Mine Health and Safety Research program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's miners.

Jan 1, 1979

By Spooner H. W

The paper describes the search for mineral deposits in an area of 4,500 sq. miles of south-west Tasmania. The area is one of difficult access and the problem of speedy movement and maintenance of field parties was solved by the use of helicopters. The programme has followed a systematic pattern of the aerial photography of the exploration area with the preparation of photQmosaics and topographical base sheets from these mosaics. Geological maps were initially prepared by photogeological interpretation and making use where possible of pre-existing information. The maps produced were later checked by ground traverses. Geophysical maps were obtained by the use of airborne magnetic, electromagnetic and radiometric methods. Geophysical and geological anomalies were checked on the ground by a campaign using ground geophysical equipment in the former case and geological and geochemical work in both instances. Audio Frequency Magnetic and Induced Polarization techniques were used in an area which was covered by several hundred feet of Tertiary sediments.The campaign has reached the stage of the drilling of specific targets.INTRODUCTIONThis paper describes the activities of Lyell-E.Z. Explorations (L.E.E.), an organization which was formed in 1956 by the Mt. Lyell Mining and Railway Co. Ltd. and the Electrolytic Zinc Co. of Australasia Ltd. to explore for mineral deposits in an area of approximately 4,500 sq. miles in southwest and southern Tasmania. To provide the necessary personnel and equipment for this project the exploration resources of both Companies were pooled and augmented and a headquarters was established in Queenstown. The work was directed by a Committee of four made up of officials from both Companies; a review of this structure has recently been presented by Hall (1959).

Jan 1, 1960

By Paul Meadows

This Bureau of Mines report presents operating practices and results of pressure maintenance and secondary recovery by water injection or by water injection supplemented by gas injection. Particular emphasis is placed on the results of water injection, which is the principal oil-recovery method employed in projects covered by this report. No attempt is made to study gas-injection projects or operations that are considered water-disposal projects. Also, this report does not include water-injection projects that have not been in operation long enough to evaluate results. Figure 1 is a map of north Louisiana showing the geographical locations of the projects included in this report. Most of the data used in this study were supplied by unit operators, operating companies, and the Louisiana Department of Conservation. Reservoir information and recovery data are generally those supplied by the operators, but include revisions where deemed necessary.

Jan 1, 1962

By V N. Rudashevsky, F Melcher, J Lodziak, D Klosa, N S. Rudashevsky, M Sitnikova, L Gast

A combination of novel and æclassicÆ methods, namely electric pulse disaggregation (EPD), hydroseparation (HS), preparation of monolayer polished sections, and mineral liberation analysis (MLA) was employed to study ores from platinum pipes (Bushveld Complex, South Africa), pristine PGE mineralisation of the Main Sulfide Zone (Great Dyke, Zimbabwe), as well as ancient and modern gold/PGM placer deposits. It is shown here that the EPD technique liberates mineral grains of interest without any visible destruction allowing the study and analysis of individual rock-forming and ore minerals, in our case especially platinum-group minerals. The HS method is an effective tool in concentrating heavy minerals by factors up to 10 000 fold. As near-total recovery of grains >10 ¦m is achieved, the nugget effect can be overcome also in case of limited availability of samples (drill core, museum specimens). The MLA technique is a fast tool to detect and characterise mineral phases in ores and ore processing products. Many mineralogical parameters of individual grains and mineral assemblages can be deducted and documented. The results show that the techniques employed, either on their own or in combination, provide a wide range of additional information especially on platinum ores which is beneficial to both the researcher and the metallurgist.

Jan 1, 2008

By Z. Sun

Imposing a strong magnetic field is considered to be an attractive method to prepare materials with aligned or textured structures due to its intrinsic properties, e.g. non-contact and easily controllable. However, the nature of the strong magnetic field effect still remains unclear and further research is needed. In the present paper, the effect of a strong magnetic field on the solidification of a hypereutectic Al-Cu alloy was investigated. After magnetic field treatment, the primary phase was aligned parallel to the magnetic field direction. Meanwhile, the eutectic micro-structural constituent became elongated and thinner. A theoretical analysis was conducted to have a better understanding of the phenomena. During solidification, the magnetic Faraday and dipole-dipole interaction forces are considered to decrease the solute pile-up in front of the solid-liquid interface and modify the eutectic cell formation. The alignment of the phase is due to the shape magnetic anisotropy and crystal magnetic anisotropy.

Jan 1, 2010

Advances in technology have led to larger and deeper open pit mines and, consequently, also increased the potential economic impact associated with slope failures. If the ultimate aim of mining operations is to maximise project profit, it is surprising to see related research activities have mostly been focusing on technical areas such as slope stability modelling, but with limited studies conducted to date to assess the relationship between geotechnical uncertainties and economic risk. Given most major decisions in the mining industry nowadays are made by management staff with financial background, any design approach that would help to link slope stability analysis results with monetary values would no doubt enhance communication between geotechnical practitioners and decision makers. This paper presents a study which assesses economic impact of slope failures to assist in mine planning. The study also estimates the impact of slope failures on project value, which would enable economic risks associated with pit slope designs to be closely examined. The proposed risk assessment techniques, used by financial institutions for many years to assess portfolio risks, can assist geotechnical practitioners in quantifying risks of slope failures. Risk-adjusted concepts are also suggested to assist management in selecting a slope design with optimal risk and return ratio.

May 1, 2010

By M F. Jennings, N J. Corlis, B J. Thomas, L N. Tylkowski, A E. Petts, G D. McDonald

Flinders Mines is an iron ore explorer and developer with a tenement package located in the Hamersley Ranges region of Western Australia, approximately 70 km north of Tom Price. Exploration over the past five years has identified a Global Resource in excess of 900 Mt at a grade of 55.2 per cent Fe (+50 per cent Fe cut-off). This resource is spread across multiple deposits and has been divided into a number of mineralisation type domains. These domains are comprised of transported hematite rich detrital iron deposits (DID) and goethite dominant channel iron deposits (CID) as well as in situ bedded iron deposits (BID). The BID at PIOP is low in alumina and silica with a high calcined iron content making it an attractive exploration target. BID exploration techniques include a combination of mapping, structural analysis, downhole gamma logging and 3D geological modelling. Relationships identified between existing BID mineralisation, geology and structure has aided in targeting additional mineralisation across the tenement and highlighted other previously untested areas that warrant further investigation.CITATION:Tylkowski, L N, Corlis, N J, McDonald, G D, Petts, A E, Jennings, M F and Thomas, B J, 2013. The hunt for hydrous bedded iron deposits - an investigation into Flinders MinesÆ Blacksmith Tenement, in Proceedings Iron Ore 2013 , pp 121-126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By C Simpson

The Pilbara region of Western Australia is well known for its abundant exports of hematite-goethite deposits, which have been mined and exported since the 1960s. Magnetite has also been mined in Australia throughout this period, although historically of much lower production volumes (WA Iron Ore profile, 2016). Magnetite offers a source supply of material >66 per cent iron grade product, which is used as premium feed (predominantly pellets) to blast furnaces or specialised steel mills.The Iron Bridge project area contains outcropping magnetite and hematite banded iron formation (BIF), which within the region was recognised as having potential to host economic mineralisation during the 1960s. Development within the project area, however, did not commence until Fortescue Metals Group acquired the tenements based on a 2004 agreement, formed a joint venture with interested groups and then initiated an assessment for magnetite (rather than hematite) mining potential. The combined deposits now have an identified large mineral resource inventory, with test work demonstrating they are able to produce a magnetite concentrate of greater than 66 per cent Fe over an extended mine life. This concentrate would be suitable for forming pellets or feed for direct reduced iron products.The deposits form a singular orebody, approximately 12 km in length by 1 km in width and extending to depths beyond 600 m. The four main deposits are geographically separate and have subtle mineralogical differences, thought driven by the degree of deformation and alteration within each area.Definition of the stratigraphy, structure and key mineralogy of the deposits has been carried out through several stages of exploration and project development. This has also included recent mining and processing of more than 1 Mt of feed material to an on-site processing facility. This demonstrated at a production scale that dry plus wet processing techniques can efficiently separate the magnetite from the gangue minerals to form a suitable (marketable) product.Geometallurgical classification of the host stratigraphy has been carried out from analysing the high volume of quantitative data available for this deposit. This has allowed definition of mappable units within the fresh BIF to be used as a driver in mine scheduling, delivering optimal feed to the processing plant.Construction of mine and processing facilities is expected to commence once all technical risks have been addressed, market conditions are deemed appropriate and approval is given by the joint venture partners.CITATION:Simpson, C, 2017. The Iron Bridge magnetite deposits, in Proceedings Iron Ore 2017, pp 287–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017