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By Robert P. Kennedy, Andrew H. Merritt, Edward J. Cording, Thomas R. Kipp

INTRODUCTION Measurement of certain data associated with nuclear testing necessitates the reception of waves at the instrument location which are unaffected by reflection off internal structures or tunnel surfaces. Therefore, in order to provide necessary facilities for the fielding of experiments in support of the underground nuclear testing program, the Defense Nuclear Agency (DNA) commissioned a cost and feasibility evaluation pertaining to the design and construction of large underground cavities in Rainier Mesa. The effort included research into past experience pertaining to the excavation and support of large underground caverns, assessment of the geological conditions which exist in Rainier Mesa, preliminary design of the chambers and their rock support systems based upon the geological setting, development of mining plans for the excavation of the caverns, and estimation of the cost and manpower schedule to complete construction. This paper summarizes the results of the feasibility evaluation. The investigation was limited to modified hemispherical configurations ranging in size from 24.4 to 91.4 m (80 to 300 ft) in diameter. Two cavity support systems were considered. The first employs internally installed rockbolts as the means of primary rock support while the second involves the use of annular tendon galleries located above the chambers from which primary support members are introduced prior to general excavation. The internal support configuration was considered for cavities with spans of 24.4, 36.6, 48.8, and 54.9 m (80, 120, 160, and 180 ft) while the external support configuration was considered for cavities with spans of 54.9, 73.2, and 91.4 m (180, 240 and 300 ft).

Jan 1, 1979

Jan 1, 1994

By J Watt

The Hidden Valley Gold Project is located in a remote and mountainous area of the Morobe Province approximately 30 km south of the township of Bulolo and approximately 90 km south-southwest of the provincial capital, Lae. The Hidden Valley deposit was discovered in 1984 with the nearby Hamata and Kaveroi deposits discovered in 1987 and 1992 respectively. Reserves (Harmony, 2009) at these three deposits are 42.1 million tonnes of ore containing approximately 2.9 million ounces of gold and 45 million ounces of silver. A further 5.4 million ounces of gold and 84 million ounces of silver are in the resources category. The process plant is designed to treat 4.2 million tonnes per year of gold/silver ore extracted by open cut mining methods. Ore is classified into three ore types according to oxidation state: oxide, transition and primary. The silver to gold grade ratio is high for the Hidden Valley and Kaveroi ores, generally in the range 15 - 20:1, and much lower for Hamata, typically 1 - 2:1: Primary ore is the dominant ore type at Hidden Valley with sulfur grades up to about two per cent sulfur. Oxide and transition ores are more prevalent at the Hamata deposit, but its primary ore has up to five per cent sulfur grades. Variable ore types, particularly in the initial years of operation, high silver to gold ratios and limited plant site area, due to the challenging terrain, present the main processing challenges for this project. This paper describes the operating strategies and process development for the main areas of this circuit, highlighting selections of processes and equipment that achieve cost effective, yet flexible solutions to the treatment of ores from these deposits.

Jan 1, 2009

By Zara Hosseini

?Microseismicity ?Seismic Systems ?Intrinsically Safe and Explosion Proof Seismic System ?Case studies: ?Gas Drainage Optimization ?Fault Identification ?Conclusion Seismic Event ?Occurrences in which energy is released in the rockmass creating a series of seismic waves propagating throughout the rockmass ?Can cause a Fall of Ground or CoalBurst Factors creating Seismicity: ?Mining at Depth ?High stress zones ?Major geological structures ?Mining practices and strategies ?Mining activities i.e. drilling and blasting

Aug 1, 2013

By K. P. Wright

"Twenty-five years ago, there were about thirty-two gold mines operating in Canada; nine of these have been in continuous operation since then and are still operating. Three of these are part of the Dome Group. Operations of these three and of the newer mines in the Group are referred to in discussing process development over the last twenty-five years.Of the Dome Mines Group, Dome Mines Limited, Sigma Mines (Quebec) Limited, Campbell Red Lake Mines Limited, Detour Lake Mine and Kiena Gold Mines Limited, three have been in continuous operation for the last twenty-five years. Dome has operated for seventy-seven years; Sigma about to complete fifty years, and Campbell approaching forty. Overall, milling processes are virtually the same as they were twenty-five years ago. Tota1 go1d production from the three mines has hardly changed; 1960 production, 416,700 ozs. versus 411,300 in 1985. Milling costs have risen by a factor of six or seven and gold price from $35/oz. in 1960 to $322 in 1985.Basic flowsheets are relatively unchanged. Sigma is an all cyanidation mill grinding in cyanide solution; Dome operates gravity concentration and cyanidation; Campbell gravity concentration, flotation, roasting and cyanidation. All three use Merrill-Crowe zinc precipitation.Detour and Kiena are two examples of the major change in gold processing in the last twenty-five years - carbon-in-pulp. This process has brought along with it other changes, such as, carbon stripping and reactivation, electrowinning, and induction furnace melting. Modern mill design with its use of outside thickeners and agitators, bulk handling of reagents, instrumentation, etc., has made a radical change in operating conditions and appearance of the new plants."

Jan 1, 1987

By R. F. Zaffarano

Data presented on the physical characteristics of the reservoir oil, Aneth field, represent the initial phase of a study of Paradox basin reservoir oils being made by petroleum engineers of the Federal Bureau of Mines, Petroleum Research Center, Laramie, Wyo. The purpose of the study is to determine the original reservoir-oil characteristics in several important new discoveries in the Paradox Basin and to investigate correlations between the properties of these reservoir oils and structural or areal position within the basin, If migration is limited and oil accumulates near its source, then it seems probable that few differences should be found in the composition and characteristics of reservoir oils occurring in given age rocks and within the confines of a geological basin. Within these limits, conditions that effected the formation of oil and its transfer from parent to storage rocks probably were rather uniform in an area the size of most of our geological basins. However, if oils should migrate considerable distances, it seems logical to expect that the relative quantities of gas and liquid components may differ in traps occurring along the direction of migration, corresponding with the theory of differential entrapment (5).4/

Jan 1, 1959

By P G. Gaylard

The minerals Industry carries out over US$ 2 billion of R&D annually. The R&D is performed at three levels ? in house research facilities; on a one-on-one basis with a research provider; as syndicated (collaborative) research. The key to a successful R&D programme is project selection. It is suggested that at this time of ?bounty? for the minerals industry the research portfolio should contain some ?blue sky? but potentially long term significantly beneficial projects. This said, the projects should align the technical concepts with the business imperatives. AMIRA has found the ?Road Map? concept has assisted in defining areas for R&D. Examples of this methodology using a Copper Road Map developed by AMIRA for the copper producers operating in South America is presented. The benefits derived from syndicated research are also discussed.

Jan 1, 2007

By I. L. Whyte

apparent density and drag coefficient of porous ores on

Apr 1, 1995

By Alexandre Gonçalves Andrade

A Samarco Mineração utiliza combustível sólido para geração de energia térmica nas pelotas de minério de ferro. Este insumo torna possível a redução da utilização de gás natural na etapa de queima nos fornos de endurecimentos e ainda melhora a qualidade física das pelotas. O tamanho das partículas é chave para eficiência do processo e a cominuição destes combustíveis é realizada nas plantas de moagem da empresa, tanto para o antracito quanto para o coque verde de petróleo. Tradicionalmente, um dos principais itens de controle de moabilidade do insumo é o HGI (Hardgrove Grindability Index), que avalia a dureza do combustível sólido no processo de moagem. Porém, este parâmetro não reflete as dificuldades produtivas encontradas nas plantas de moagem da Samarco Mineração. Portanto, foi desenvolvida metodologia através de uma modificação da equação proposta por Bond para avaliação energética de moagem. A lei de Bond tem origem empírica e considera que a energia consumida na cominuição é proporcional ao comprimento das fissuras iniciais que se desencadeiam na quebra das partículas. A metodologia proposta, no presente trabalho, avalia com maior representatividade as dificuldades encontradas na cominuição destes insumos. Ainda, testes em planta piloto de moagem de combustíveis sólidos foram realizados para validação da abordagem.

Aug 1, 2018

By Chikaosa Tanimoto

INTRODUCTION Bratislava is located at the intersection of important traffic routes, including motor-ways, roads, railways, air traffic, trading, and inland waterway with an important harbour. The construction of the D2 Motorway Bratislava, Lamacska cesta Stare grunty was the last missing section of D2 Motorway and its completion linked the Czech Republic through Bratislava to the Hungarian Republic. Traffic was obliged until its completion to use the Lamacska Road and Mlynska Dolina, which were the most heavily trafficked roads in the city. The section of D2 Motorway to be completed in 2006 was 3,300m in length, of which the SITINA Tunnel was approximately half the length. After putting into operation the transit traffic(motorway) and urban traffic was separated. Transit traffic by passing the town was eased. The junctions D2 with Lamacska Road (Harmincova) and Mlynska Dolina also allowed better use of the motorway for the urban traffic The tunnel construction was specified by the features with the highly weathered and thermally altered granitic rock formation with the overburden of Quaternary sediment of 2?4 m thick, very thin overburden, severely controlled deformation limit and environmental protection. The tunnel had to be excavated beneath and nearby the academic complex area and the zoo, where sensitive facilities exist and animals live in. The tunnel consisted of two tunnels (Tunnel A and B) with the length of 1,415 and 1,440 m, respectively. The overburden thickness was in the range from 10?30 m. The standard cross-section and the one with invert arch were 79.5?81.5 m2 and 92.1?93.3 m2. The excavation took 21 months from September 2003 to May 2005. The construction was based on the concept of NATM. The SITINA Tunnel was the third application of NATM in Slovakia, following the BRANKISKO Tunnel (commenced in July 2003) as the first and the HORELICA Tunnel (in October 2004) as the second NATM practice. To protect the surrounding structures and citizens from tunneling operations, seismic monitoring was performed in association with blasting. The allowable limit of blasting vibration was fixed to be under the particle velocity of 15 mm/sec. The tunnel excavation cleared this limit as expected before construction. In driving through the difficult geological situation the excavation work hit 49 faults, and some of them occasionally caused serious face instability. In principle, the rock formation has been affected by the high hydrothermal effect and the resultant clay filing along faults and joints. The auxiliary reinforcement with the 4?8 m long pipe roofing was needed to protect the vicinity of mining face area. This operation extraordinarily required additional works and time which had not been expected before construction.

By David S. Yang

The Cement Deep Soil Mixing (CDSM) method introduces and mixes cementitious materials with in situ soils using hollow-stem rotating shafts equipped with a cutting tool at the tip and mixing paddles above the tip. CDSM generally produces a soil-cement panel consisting of three overlapping soil-cement columns. The soil-cement panel is then extended to form walls, which are effective for excavation support and groundwater control due to the continuity and low permeability of soil-cement walls. Two design approaches could be taken in the application of CDSM for excavation support: 1) single wall design and 2) gravity wall design. The former one is treated as a wall technology and the latter one is treated as a soil stabilization method. This paper will review the CDSM equipment and installation procedures for the construction of these two types of soil-cement walls. Four case examples are used to illustrate the design and application of these two types of soil-cement walls.

Jan 1, 2003

By Ronald S. Conti

The Bureau of Mines conducted a comprehensive laboratory study of the thermal ignitability of various carbonaceous dust clouds with particular emphasis on various ranks of coal dust. The tests were conducted using a new 1.2-L furnace. Autoignition temperatures of dust clouds were obtained as a function of coal volatility and particle size. Dust particles and gas samples were collected by a rapid-sampling system in order to study the reactions involved in preignition and postignition processes. The autoignition temperatures measured in the new 1.2-L furnace were significantly lower and therefore more conservative than those measured previously in the Godbert-Greenwald furnace. The combined effects of thermal and electrical ignition of dust clouds were also studied in the 1.2-L furnace using electrical discharges of varying energies at ambient and elevated temperatures. The minimum spark energy necessary to ignite a dust cloud decreased significantly as the temperature of the dust cloud increased.

Jan 1, 1983

By Brian L. Beninger

This paper discusses the application of the computer to coal preparation process predictions. In broad terms, the computer is used to perform two main functions. Firstly, the given float-sink analysis is interpolated and extrapolated to cover the entire actual range of raw coal specific gravity. Assumptions based on historical data must be made at times. Secondly, the partition curve, which, from historical data, defines the efficiency of a specific coal washing process, is applied to the washability data in order to determine the expected clean coal yield and quality. The vast amount of numerical work which is required to make a prediction of this type exhibits the need for computer methods in this area.

Jan 1, 1979

By Eugie Kabwe

The increase in depth of mines due to the depletion of surface deposits leads to unsafe tunnel construction and overall ore extraction. This is due to tunnel instability associated with the surrounding rock mass’s ability to exhibit creep that occurs over time. However, the explicit description of this mechanism using conventional constitutive models has proven to be difficult and inadequate. Hence, this paper presents an integrated viscoelastic viscoplastic visco-damage model with the Duvaut-Lions function. The presented model is calibrated by experimental data to determine the viscoelastic viscoplastic and visco-damage parameters. It is further implemented in a finite volume numerical code and verified on an experimental scale by numerical modeling of a cylindrical specimen. It describes the 3-phase creep mechanism perfectly as compared to the inbuilt conventional integer-order derivative model. Results from the conducted verification show that it can successfully be employed to describe the long-term behavior associated with the creep mechanism.

May 16, 2021

By Uusna S, Canning R. G, Goodheart B. A

The development of a process for removal of iron oxides from ilmenite is outlined whereby the Ti02 content of Western Australian ilmenites can be upgraded from 55 to approximately 90 per cent. In the first stage, the iron oxides are reduced with solid carbon (coal) to metallic iron. Experimental reductions were carried out in crucibles, a fluidized bed, and a small pilot plant rotary kiln. The reduced ilmenite was then agitated in aerated water, in the presenceof catalysts, so that the iron "rusted" away from the ilmenite grains and the precipitated iron oxide was easily separable by decantation.The influence of variables on the rates of reduction and oxidation are discussed. The oxidation rate was examined for both the physical oxygen transfer characteristics and electrochemically by reference to Pourbaix diagrams, in which redox potential is plotted against solution pH.The upgraded ilmenite is expected to be an attractive material for pigment manufacture, and the iron oxide has prospects of being a marketable by-product. The process may possibly be applied to other ores.INTRODUCTIONThere are extensive deposits of ilmenitic beach sands, Le. iron titanium oxides of the general formula FeTi03, 'occurring in the lower south-west portion of Western Australia, and although there has been considerable commercial development, local producers face keen competition on a freight-cost basis. Thus the removal of the unwanted iron oxide constituent would have the double advantage of reducing the freight differential and presenting a more attractivematerial to pigment manufacturers.

Jan 1, 1965

By S. H. Ash

THIS REPORT covers the third in a series of five projects into which the Conowingo tunnel system has been divided for geographical and practical reasons. It outlines the work constituting Project No.3 that consists principally of the following: (a) To sink the No. 15 shaft and extend the Alden, Sugar Notch, Baltimore No.2, and Laflin shafts from their present depths to tunnel level; (b) to drive a tunnel off these shafts to connect with the western end of the tunnel in Project No.1 (Lackawanna) and to a point 1 mile south of the No. 15 shaft; (c) to construct an emergency pumping plant at the No. 15 shaft, complete with 3 centrifugal pumps of 200-cubic-foot-per-second (c. f. s.) capacity each, and a discharge-water shaft and a discharge tunnel for conducting the water from the pumping plant into the Susquehanna River; and (d) to construct a lateral tunnel 1 mile long off the main tunnel in the vicinity of the No. 15 shaft, to be known as the Wyoming lateral. The project, as outlined, is a self-contained drainage unit that will permit unwatering inundated mines and safeguarding active mines in the Wyoming Basin of the Northern field and also will handle the water in the Lackawanna Basin, thus permitting the temporary pumping plant provided in Project No.1 to be discontinued. The pumps installed in the temporary pumping plant provided in Project No.1 can then be moved to the emergency pumping plants recommended in Projects Nos. 2 and 3, to be installed as the third or standby unit.

Jan 1, 1955

1. In 2002, a total of 2,820 contracting companies reported employment at coal mines to MSHA.

Jan 1, 2004

By R. E. Mussier

This investigation was made to study new methods to prepare high-purity yttrium metal, Various methods were used to prepare pure intermediate compounds, primarily chlorides, bromides, and iodides, which were subsequently reduced to metal. The process found most suitable for the preparation of pure anhydrous yttrium chloride involved thermal dehydration of a mixture of hydrated yttrium chloride and ammonium chloride while under vacuum. Yttrium bromide and iodide were prepared most effectively by the direct halogenation of yttrim carbide. Yttrim carbide was obtained by reacting and melting yttrium oxide-carbon mixtures in a carbon-arc furnace. Yttrium halides were purified by vacuum distillation and reduced by alkali or alkaline-earth metals. Lithium and sodium proved to be the best reductants from the standpoint of yield (>95 pct) and purity (>99.8 pct) of the yttrium. The product of the reduction step was sponge metal, which was consolidated readily by conventional cold-mold, arc-melting procedure. The purest yttrium obtained in laboratory scale work was prepared by sodium reduction of yttrium chloride and contained only 125 pp oxygen; other impurities did not exceed 1,000 ppm. In larger scale tests yttrium containing only 800 to 1,000 ppm total impurities was obtained by lithium reduction of yttrium chloride. The tensile properties of high-purity yttrium were determined. Mechanical tests showed that yttrium can be forged, extruded, rolled, spot welded, and deep drawn.

Jan 1, 1963

By D. van der Veen

Mining companies and contractors are looking at Wirtgen Surface Miners to provide flexibility at their operations. Wirtgen Surface Miners have been used in the surface mining industry for over fifteen years. The principle behind the Wirtgen Miner is a rotating drum equipped with tungsten carbide tipped cutting tools that excavates and sizes the material. The drum helix augurs the mined material to the center of the drum where it is loaded onto the primary conveyor belt. From there the material is conveyed to the discharge belt and into a truck bed. The cutting drum is located in the center of the machine, near the center of gravity. This permits the machine to cut hard materials as the entire machine weight is converted into cutting forces. Conventional mining practices are process, equipment, and labor intensive. Furthermore, strict environmental requirements pertaining to noise levels, dust pollution, and blasting, near buildings or urban areas, limit the application of conventional methods. Mining/ Construction contractors are using Wirtgen Miners in various limestone excavation projects, such as highway expansion projects, and new roads in housing developments. Mining companies in the industrial minerals and coal industry are using Wirtgen Miners to load directly onto trucks, eliminating the rehandling process and ultimately, primary crushers.

Jan 1, 2002

By Adrian Moore, John Wilson, Alan Richards, Emad Gad

Project C9040 – ‘Structure Response to Blast Vibration’, funded by the Australian Coal Association Research Program (ACARP), involved the investigation of the structural response from blast vibration of three houses of brick veneer construction subject to a wide range of ground vibration levels. This paper summarises the findings of a house subject to vibration levels up to 220 mm/s (8.7 in/s). Damage attributable to blast vibration was not observed until vibration levels exceeded 70 mm/s (2.8 in/s).

Jan 1, 2003