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The Golden Cross mine is a Joint Venture between Coeur Gold New Zealand Limited, as Manager, and Viking Mining Limited The mine is targeting Zero Lost Time Accidents as a goal. The Golden Cross operation produces gold and silver from both underground and open pit. The mine is based on an epithermal gold-silver deposit. Treatment of ore is on a campaign basis for each ore type (ie underground or open pit). Milling is conventional SAG Mill and Ball Mill grinding circuit followed by carbon in pulp recovery of gold and silver. All tailing materials are treated through the Cyanisorb process to reduce cyanide levels prior to being discharged into the tailings dam.

Jan 1, 1995

By Mackenzie Burnett

This program was initiated by USBM to quantify the respirable dust problem caused by the use .of roadheaders in underground metal/nonmetal mines with special emphasis on this problem in uranium mines. The contract called for the development of methods or equipment to alleviate the respirable dust and to implement the solution in a mine. Attempts to quantify the dust problem were made in the following way: survey of MSHA records, survey of state mine enforcement agencies, survey of mine records, dust measurements taken at two mines using roadheaders. The results of this study are not conclusive due to very limited and sometimes less than useful data; however, the study does indicate that a serious dust problem could and may exist. If and when roadheader use becomes more popular, it is almost certain that development of dust control procedures and equipment will be necessary. This contract was concluded without developing this equipment since only one roadheader is currently in use in an American uranium mine and the mine prefers not to participate in the program at this time. This report discusses the available data concerning respirable dust problems and presents a solution which can potentially help to solve the problem. The solution requires the use of blowing ventilation, on-board dust extraction at the source, and filtration, as well as continued use of water sprays. The on-site tuning of such a system is necessary to demonstrate the degree of improvement possible.

Jan 1, 1981

By J. E. Russell

The purpose of this paper is to describe an independent study which forecasts Texas coal production, specifically for electric power generation. This study, extending to the year 2000, is justified on the following basis. Texas produces and consumes considerably more electric energy than any other state, has consistently high growth rates in the population and industrial sectors, and has large lignite reserves. Also, since recent forecasts have been criticized as overly optimistic, this study is timely when considering the long lead times required in obtaining new power sources. In the study demand for electric energy was assumed to rest on two dominant factors: 1) overall state of the Texas economy as measured by the Texas Gross State Product (TGSP) and 2) Texas population. Demand models were prepared and tested following a study of several options. A final linear regression demand model with time lags for the two variables was chosen on the basis of good correlations. On the supply side, uncertainties such as impact of nuclear sources, gas-fired cogeneration, and ratio of imported to lignite coal exist. These uncertainties were studied with high and low cases for effects on lignite. Finally a simple supply model was chosen. Results of the study indicate that lignite production in Texas will rise from the current (1984) 40 million tons per year (XTPY) to the range of 77 to 124 MTPY and more probably 100 HTPY in the year 2000.

Jan 1, 1984

By J. Loubser

The concept of caring is in most cases confused with material needs and not psychological needs. By giving employees a job, most managers think that employees should be grateful and return the favour by being loyal, productive and working safely. Other managers hold the view that employees can be lucky to have a job. To show and demonstrate that management are caring for the safety of the workforce requires involvement, dedication and commitment. Obtaining the trust and respect of the workforce should be the main thrust of any organization because within trust and respect lie the secret of optimal safety performance. In the last 70 years, all the fatalities and serious injuries that occurred in the mining industry can be traced back to one thing, non-caring. The same safety non-compliances are still observed, reported and planned against as 70 years ago, and strange as it may sound, the same injuries occur the same way. The question could be asked: Does the mining industry need more risk assessments? More codes of conduct? More engineering. Or does the mining industry need more caring?

Jan 1, 2010

By D Bruggemann, F Sereshki

There has been an ongoing research on coal and gas outburst for the past two decades at the School of Civil, Mining and Environmental Engineering, University of Wollongong. Research study began with a humble beginning, initially conducting basic laboratory studies on the coal and gas properties, progressing into the determination of gas content of coal by sorption technique and the effect of gas pressures on coal strength. The present laboratory facilities and research interests are extended to include the study of coal permeability and shrinkage properties and their effect of gas drainage characteristics with respect to gas type, and pressures. All the changes are examined with respect to changing in-site geological conditions of the coal deposit investigated. The aim is to provide a long-term support to industry in establishing a data bank for Australian coal deposit characteristics and properties.

Jan 1, 2005

This publication summarizes, for all interested parties, the research, development, and demonstration in-house projets programed by the Bureau of Mines for fiscal year 1980 (October 1, 1979 - September 30, 1980) under its Minerals 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 mining and minerals processing workers.

Jan 1, 1980

By Sheila Luchansky, F M. Babcock, Daniel M. Sanders

A cooperative effort between a blasting vibration consultant, a blasting contractor, and personnel from the City of Las Vegas has dramatically reduced complaints from residential areas near developmental blasting projects. The principal methods used involved the preparation of an informative video recording which presents various aspects of the blasting operations, the design of a distinctive flyer which is attached to residential doors, and pre-blast meetings for information dissemination.

Jan 1, 1993

By W. Robert Power

Petrographically these range from true granite and syenite to gabbro and anorthosite. Commercial limestone is any sedimentary rock composed predominantly of the minerals calcite and/or dolomite. Commercial marble is any crystalline rock composed predominantly of calcite, dolomite or serpentine that is capable of taking a polish. Marble comes in a wide variety of color, texture and pattern. Many commercial marbles are unmetamorphosed limestone, to the geologist or petrologist but if they take a polish, are classified as marble.

Jan 6, 1972

By D. Stone, N. J. Aslin, W. Webb

In today's modem copper electro-refineries, increasingly higher average current densities are being employed. With these increases many refineries are approaching their limiting current density. The nearness of the average operating current density to the limiting current density has placed increasing emphasis on the need to maintain an even current distribution. This paper explores the importance of maintaining even current density and discusses the factors, processes and practices that are necessary to achieve and maintain high quality production at high operational intensity.

Jan 1, 2005

By J. N. Tomlinson

Trailing-cable splices are evaluated for moisture exclusion abilities after repeated travel over shuttle-car sheave wheels. Tests are conducted on cables with jackets made of neoprene, cholrosulphonated polyethylene (CSPE), and nitrile butadiene-polyvinyl chloride (NBR-PVC) to 50° C. The results show that some splice kits are effective as received, others are improved with minor but significant changes, and still others must be redesigned to be effective in underground applications. Laboratory results are compared with actual underground splice results. Recommendations for cable preparation prior to splicing are presented.

Jan 1, 1979

By Frank Manheim

The purpose of this presentation is to review the history of offshore non- fisheries resource development since World War II, as an introduction to a planned symposium on offshore resources scheduled for the 1996 UMI Conference. After World War II the United States became the leader in offshore oil and gas production, deep ocean drilling technologies, offshore terminals, platforms and production systems, and natural gas recovery and transport. Wartime skills in acoustic profiling and antisubmarine warfare were transferred into commercially important geophysical exploration techniques. The application of ocean drilling and geophysical techniques permitted the recognition and elucidation of plate tectonics patterns, development of seafloor spreading theory, and the transformation of our knowledge of seabed and subseabed strata. After John Mero's studies and recommendations for developing marine manganese nodules in the late 1950's interest in nonfuel minerals grew rapidly. The formation of international deep sea mining consortia in the 1960's was accompanied by a flurry of ocean engineering development, minerals prospecting and associated environmental studies The Santa Barbara Oil Spill of 1969 resulted in a moratorium on both offshore energy and minerals leasing by the Depart- ment Interior, and catalyzed the development of new Federal legislation in 1972. In 1973 the offshore energy moratorium was lifted in response to the Arab oil embargo, and offshore energy activities surged for a time. Minerals were reopened to leasing following President Reagan's 1983 executive order implementing a 200 mile EEZ. Although interest was spurred by

Jan 1, 1995

By Andrew W. Jenike

The first significant studies of problems related to the handling and storage of bulk solids were reported at the end of the nineteenth century. Early work originated from the necessity to store large quantities of grain and was concerned mainly with pressures affecting the structural design of silos and bins. The Janssen formula (about 1898) and the work of Ketchum [1] form the highlights of that period. In more recent years, progress in mechanization, increasing plant capacities, and rising costs of labor have focused the attention of engineers on the problem of gravity flow of bulk solids. A great deal of work has been done with models, and flow patterns obtained in small scale bins have been described in several publications, for example [2, 3]. An attempt to develop a theory of flow of bulk solids was reported in 1954 [4, 5, 61 and presented to the in a paper [7] in the same year. AIME recommended the continuation of this work and, as a result, Engineering Foundation granted a sum of money to set up a Bulk Solids Flow Laboratory. Two and a half years ago the project gained the support of the University of Utah and a laboratory was set up on the campus of the University. This project is now in progress, it has received the support of the American Iron and Steel Institute and of Kaiser Engineers, Division of Henry J. Kaiser Company. The results obtained to date are summarized in this report.

Jan 1, 1959

By Takeshi Shinohara

It is a great honor and pleasure for me as President of the Japanese Tunnel Association to send greetings to the 1974 Rapid Excavation and Tunneling Conference. Recently in Japan, the Japanese Tunnel Association was established as recommended by the OECD Advisory Conference on Tunneling. This is a central organization concerned with tunnel construction consisting of government authorities, universities' research institutes and construction firms as well as manufacturers of relevant materials and equipment. As I was chosen the first president of the newly-established Japanese Tunnel Association, I would like to avail myself of this opportunity to announce to you its establishment and its earnest wish to contribute to the development of tunneling technique not only in our country but also all over the world. At the same time, I cordially request your friendship and cooperation for the benefit of further development of tunneling techniques on both sides of the Pacific. At present, many tunnels are under construction in Japan. The total length of tunnels under construction for railways and highways is about 600km including the 54km Seikan Undersea Tunnel which connects the Main Island and Hokkaido. Naturally, for construction of such tunnels in Japan, we have introduced much equipment and technique from the United States and other foreign countries. Now with accumulated experience, we are confident to be able to furnish various useful information concerning tunnel construction.

Jan 1, 1974

The most critical step in the development of any mining project is the completion of a feasibility study. The feasibility study has one primary goal; to demonstrate that the project is economically viable if it is designed, constructed and operated in accordance with the concepts set forth in the study. Starting from a mineral resource data base, the feasibility study will define the ore reserves, the mining methods, the mineral processing concepts and the scale of the project. The disciplined activity of developing a feasibility study leads the proponent to examine every aspect of the project, many of which might otherwise be ignored. All technical concepts will be established and the corporate philosophy with respect to organisational structure, social and environmental responsibility, infrastructure contributions and financing will be determined. All the major decisions about how the project will be developed are made during the feasibility study. The success of the project will then depend upon the assumptions and decisions in the feasibility study and the ability and empowerment of the development team.

Jan 1, 1997

By L. C. Brown, J. S. Kirkaldy

Measurements have been made of carbon diffuswn in the five ternary austenites Fe-C-Si, Fe-C-Ni, Fe-C-Co, Fe-C-Mn, and Fe-C-Cr in which the carbon (component 1) diffuses through interstitial sites and the ternary addition (component 2) diffuses substitutionally. Values of the diffusion-coefficient ratio, D12/D11 were determined for each system with finite couples using the transient equilibrium method. The effect of temperature and of concentrations of both the carbon and substitutional component upon D12/D was examined and was found to agree with the theoretical predictions. It is concluded that within an experimental uncertainty of 10 to 15 pct, it is possible to calculate the ratio D12/D11 from purely thermody-namic data. Difficulties of measuring the other off-diagonal coefficient, 4,, are discussed. Any quantitative attack on the fundamentals of the hardenability problem in steel must begin with the multicomponent diffusion formalism and with the accumulation of data pertaining thereto. In a recent paper Kirkaldy and purdy 1 employed the formalism derived from irreversible thermodynamics to treat the problem of diffusion in ternary austenites. In the latter solutions, carbon diffuses through interstitial sites and the substitutional component diffuses through the lattice. Examples were given of diffusion in the systems Fe-Mn-C and Fe-Si-C. In the present paper, we present new results on and discuss their agreement with the thermody-namic theory. Since the theory has been slightly modified from the original presentation of Kirkaldy and Purdy, their results on Fe-Si-C and Fe-Mn-C have been recalculated and are presented here for completeness. The flux of the interstitial component with respect to a fixed lattice framework can be written as a linear expansion in the independent concentration gradients, where X1 and X2 are the independent thermody-namic forces in the lattice fixed frame of reference. These forces can be obtained from the general statement for forces in a volume fixed frame2 if the partial molar volume of carbon atoms is set equal to zero and that of the substitutional component 2 is set equal to unity, viz where the are the chemical potentials and the N's are mole fractions. Introducing into [3] and [4] the function If, as suggested by statistical arguments, the off-diagonal interaction L12 is sufficiently small, [6] reduces to i.e., the coefficient ratio becomes purely thermo-dynamic. The activity of components 1 and 2 in a dilute ternary system (standard state at infinite dilution) may be represented by the expansion3

Jan 1, 1964

By Leon Merker

FLAME fusion growth of strontium titanate crystals was undertaken to obtain large transparent crystals on which physical data could be gathered. The fact that strontium titanate is a cubic crystal and probably has a high index of refraction indicated that it might be useful in optics. No large boules* of strontium titanate had been synthesized previously, and none have been found as natural occurrences. The flame fusion process, invented by Verneuil in 1904,1 was first applied to grow large crystals of ruby and has since been used extensively to grow crystals of corundum and spinel on a commercial scale. Only during the past nine years has this technique been applied to the growth of large single crystals of other high melting compounds such as rutile,2 mullite,3 and ferrites4 One of several significant advantages of the flame fusion technique over more conventional methods of growing crystals from a melt is that the crystals are grown without the use of melt containers. This fact alone excludes other methods of growing crystals from a melt whenever there are compounds with a melting point near 2000°C or above. Growth of the crystal, similar to that of a stalagmite, takes place inside a circular refractory furnace that does not contact the crystal, Fig. 1. This eliminates a serious source of impurities as well as the likelihood of multi-crystalline solidification along the container walls. The flame fusion technique is particularly advantageous for research because it produces large crystals quickly and at lower cost. A corundum crystal 25 mm long and 12 mm in diam can be grown in 2 to 3 hr. Operating conditions permit observation of the growing crystal during any stage of the process. The various flame patterns and a wide range of oxidation-reduction conditions can be investigated in a relatively short time. It should be pointed out that formation of the foot of the boule is the most critical step in growing an unfractured boule. When the tip of the sintered cone is fused to initiate crystal growth, the original area of fusion should be kept as small as possible so that one crystallite can assume dominance over all the others and propagate as a single crystal. If the boule start happens to consist of several crystals, usually the entire boule also contains several crystals. In many cases these tightly cohering crystals exhibit different crystallographic orientations. Although the basic technique of the original Verneuil process has been retained, refinements in method and burner design have been developed in recent years. For example, boule growth may be initiated on a seed crystal rather than by fusion of a sintered cone. The danger of multicrystalline or twinned boule starts is thus eliminated, and this procedure may also be used to grow boules of predetermined crystallographic orientation. Prior Art: Of the many attempts to produce artificial gem crystals, most early efforts% ere directed toward synthesis of .rubies and sapphires and diamonds. None of these efforts resulted in a process that was commercially practical. Without exception only tiny crystals of corundum were obtained, and those at excessive cost. Verneuil announced his process in 1904; Ravier6 in 1934 presented a detailed description of a commercial boule production plant. Descriptions of the German synthetic stone industry, the process details, and the equipment used have been published by Barnes7 and by Merker.'

Jan 1, 1956

By Keith G. Wallace, Gary K. Rogers

As a supplement to an analysis involving methodologies for the estimation of airflow resistance in shafts used for both ventilation and hoisting, a detailed shaft characterization survey was distributed worldwide. The survey provided detailed information which enabled verification of recommended velocities and established limitations on fill factors and relative velocities. This paper evaluates the information obtained for 37 shafts and presents a statistical evaluation of the results. Apart from airflow rates, conveyance rates, and physical characteristics, qualitative information regarding means of conveyance stability and velocity control techniques at unloading and loading points are also presented. Calculations of fill coefficient, free area velocity, and most importantly, relative velocity between the airflow and hoist, are conducted. These results are presented by frequency diagrams which illustrate the trends, as well as provide limitations for these parameters. The data illustrates that, commonly, the fill coefficient for two or more conveyances, does not exceed 30 %. A limit of 50% is suggested for a single conveyance shaft. A recommended free area velocity of 10 m/s (1,970 ft/min) for combined ventilation and hoisting shafts, is sup- ported by these results. Relative velocities of 30 m/s (5,905 ft/min) are most frequent and 50 m/s (9,840 ft/min) being a practical maximum.

Jan 1, 1987

By Jean Michel Marino, Jean-Pierre Slama

"The computer methods used by the French Commissariat a l'Energie Atomique, which are applicable to any type of ore deposits, are:(i) Ore reserve estimation. The data are either the core analyses or gamma leggings. To determine the spatial distribution of the ore, three different methods of interpolation are used. Two of these are based on the least-squares theory and the third one is an application of the regionalized variable theory. The interpretations of the orebody by the geologists are introduced in the computer program as often as possible.(ii) Optimal open pit design. From the spatial distribution of ore, the three-dimensional outlines of the optimal pit are determined by a geometrical algorithm which allows different slopes varying with the azimuth.Finally, the optimization of annual successive plans arc discussed."

Jan 1, 2014

By J. S. Oram

Maltby Colliery, operated by RJB Mining (UK) Ltd is successfully mining the Parkgate seam in Yorkshire at a depth of 1000m using longwall retreat. Extraction in the Parkgate seam is influenced by interaction from previous workings in the Swallow Wood Seam 160m above. The paper describes in-situ stress measurements and simple gate road convergence measurements carried out to assess the extent of the interactive influence. The stress measurements, obtained using the stress relief overcore technique, were carried out from a maingate development roadway in an area where the stress redistribution under an overlying pillar and adjacent panel goat could be measured. The measured vertical stress distribution confirmed a significant interactive influence with high imposed vertical stresses under the overlying panel edges. Simple roadway convergence monitoring stations established in the gateroads of a retreating panel and in the development gateroads of the adjacent panel, confirmed higher rates of roadway deformation relating to overlying panel edges and pillars, particularly in the areas where a vertical stress window developed during panel retreat. In addition to highlighting a close relationship between closure rate and the measured vertical stresses, the convergence monitoring proved valuable in establishing characteristic deformation behaviour under specific interactive influences and also in defining the optimum location, extent and time of installation u£ additional roadway support and reinforcement. The information from the measurement programme has enabled the Mine Management to gain a better understanding of the interactive influences on roadway behaviour and was instrumental in designing the layout of panels in an area of the North East district of the mine where previous experience had indicated the combined influence of high interactive stresses and weak roof lithology resulted in difficult strata conditions both at development and on panel retreat. The planned location of panels and gateroads took into account both mining operational considerations and the need to avoid potentially high risk interaction zones as highlighted from analysis of the monitoring results. To obtain additional data on parameters influencing roadway deformation, extended roadway convergence monitoring has been established.

Jan 1, 1997

By Adriana Gómez

White dross is a result of the aluminum oxidation during its primary production and is mainly composed of metallic aluminum, Al2O3, with minor amounts of AlN and some other oxides. Because of the great variety of phases, the quantitative characterization is complicated. This work shows a quantitative method to determine the main phases of white aluminum drosses by means of X-ray diffraction (the Rietveld method). Nowadays the Rietveld method is maybe the most useful method for obtaining quantitative phases information in multicomponent mixtures, this method permits relatively quick quantitative phase analysis by fitting the calculated X-ray diffraction profile with the observed one. The analysis were done using powder with a grain size less than 45 µm; to obtain the suitable material size the aluminum dross was grounded by ten minutes, several times. The grounded material was screened, and the material smaller than 45 µm was taken to quantitative XRD analysis. Keywords: Rietveld Method, Characterization, Aluminum dross.

Jan 1, 2005