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Study on the Effects and Mechanics of Na2SO3 to Chalcopyrite and Galena

Sep 13, 2010

By J. D. Appleton, J. Ridgway, K. B. Greally

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). The results suggest that meaningful geochemical maps can be produced from very low-density surveys, and that existing data sets could perhaps be incorporated into such a map series with the use of a system such as Uniras software. There are still many problems to be resolved, however, including the compatibility of data derived from different analytical methods, and the precise methods to be employed will necessarily require international agreement. Sampling densities should be chosen on the basis of the scale of the geochemical and geological features to be distinguished and will vary from region to region. Reanalysis of selected samples from archives to increase the range of elements determined or to unify analytical methods is only likely to be effective if the original survey was at quite a low density

Jul 1, 1991

By Nabil F. Ismael

The axial capacity of step tapered bored piles in sand was examined by field tests at one site in Kuwait. Two straight piles, and two step tapered piles were load tested in compression to failure. All four piles were 3 m deep. The straight piles were 0.2 m in diameter. The step tapered piles had a diameter of 0.3 m for the upper segment which extended up to 40% of the pile length changing to 0.2 m diameter for the lower section. The soil profile consists of medium to dense sand with minor cementation and no groundwater was encountered. Both the ultimate bearing capacity and the settlement at working loads were examined. The axial capacity of the step tapered piles was greater, and the settlement at working loads was less, compared with the straight shaft piles. The increase in capacity is mainly attributed to the added side friction along the larger diameter top segment of the shaft.

Jan 1, 2008

By W. G. Pariseau

"The Crandall Canyon Mine (CCM) is located in the Wasatch coal field in central Utah. Extensive longwall mining at CCM preceded a decision to recover coal left in barrier pillars on each side of a set of main entries extending far into the mine. During mining in March 2007, a major bump occurred that led to cessation of mining in the barrier pillar on the north side of the mains and to the start of mining in the south barrier pillar. Subsequent loss of ground control in August 2007, through coal pillar bursts had tragic consequences with loss of six miners and shortly afterward three rescue team members. A U.S. Mine Safety and Health Administration (MSHA)report describes the events in detail (MSHA, 2008).An important lesson to be learned from CCM is the need to select a computer program suitable for pillar design. Computer programs are engineering tools and selecting the right tool for the job is essential. In this regard, minimum program requirements include capability for computing stress distribution within a pillar and adjacent roof and floor strata. The reason is simple: strength of rock is stress dependent; both vary from point to point in pillars and adjacent strata. Preferably, one should follow the evolution of stress as the mining plan is executed from start to finish to assure safety or to warn of a potentially hazardous situation developing as mining progresses.The approach to the problem posed by barrier pillar mining at CCM is conventional in the sense of applying well known finite element modeling techniques to analysis of a proposed mining plan. The engineering purpose is to evaluate the mining plan with respect to ground control questions including roof, floor and pillar safety. Results of previous two-dimensional finite element analysis indicated pillar safety was by no means assured (MSHA, 2008; Pariseau, 2008; Pariseau, 2011). Geometry of barrier pillar mining is limited in two dimensions for example, crosscuts are not seen in vertical cross sections. While three-dimensional analyses are preferred, even moderately sized regions often lead to very large problem sizes that exceed computer capabilities. However, a recent development in finite element modeling of tabular deposits allows for whole mine analysis in three dimensions. This technique involves a dual node - dual mesh concept. Both have been used separately in much earlier work, but are only now used in combination. It is possible to have an estimation of subsidence at a kilometer scale and details of stress, strain and displacement about barrier pillars, main entries and pillars, and so on at a meter scale (Pariseau, 2014). No compromise involving empirical formulas or similar guess work is required. Indeed, all calculations are based on first principles: physical laws, kinematics, and material laws. Effects of joints and in situ variability or uncertainty in strata properties, elastic moduli and strengths, may be included for greater realism. An important objective of the present study is to assess the role of three-dimensional pillar geometry in arriving at conclusions regarding barrier pillar mining versus two-dimensional results."

Jan 1, 2014

A study of the accessory opaque iron-titanium oxide minerals of the Oiles Complex, central Australia, was an Important complement to an investigation of the magnetic properties of the Complex. These minerals constitute no more than 10 per cent of the rocks sampled, and generally less than 1 per cent of the ultramafic rocks ("magnetite" concentrations were not sampled for magnetic investigation).Titanomagnetite is the main opaque mineral present, although ilmenite exsolution has been widely developed. High-temperature oxidation of these produced mainly titanohematite, pseudobrookite and rutile. Both exsolution and high-temperature oxidation developed along specific crystallographic directions (along {111}), and in Irregular patches. Low-temperature oxidation is generally not well-developed, indicating the small degree of weathering in the rocks sampled.Although the Oiles Complex is layered, no apparent overall preferred orientation of the iron-titanium oxide minerals was observed, other than crystallographically controlled alignment of very fine grains within pyroxene crystals. Other textural features of the opaque oxides are restricted to symplectic intergrowths mainly with the ferromagnesian silicates.

Jan 1, 1971

By Robert Lee, Jeff Corace, Rob Cyr

Blasting in the heart of the historic Byward Market District of Canada’s capital, Ottawa, presents a unique set of challenges. The obvious difficulties arising on projects requiring blasting within 3 m (10 ft) of 125 year old buildings in various states of disrepair have been encountered and successfully dealt with countless times before. The complexities increase exponentially when tenuous property boundaries, unknown structural details, litigious histories and the need for encroachment agreements lead to individuals with competing interests all able to impact the same operation. Blasting on three projects in the Market was started in early 2005 after months of negotiation. Ultimately, the potential for the projects to proceed hinged on the ability to successfully disseminate blast data to the various stakeholders. As part of the agreements drawn up, property owners demanded immediate notification of the measured vibration levels with contract provisions including clauses such that any exceedance of the USBM criteria immediately triggered project shut down and complete blasting program redesign, and approval by all parties. With stakeholders located in various cities and, in some instances, on various continents, a conventional attended monitoring strategy would not satisfy the requirements. In response to the critical reporting need, Explotech Engineering Ltd. installed unattended monitoring stations around the sites, all incorporating wireless telemetry. After each blast, data was automatically transferred from the monitoring stations to a web-linked server via the wireless network, where it was immediately available to project stakeholders through a password protected website. The solution required a unique blend of data acquisition, telemetry, database, and security technologies, all married to produce a reliable system that was easy to maintain and use. While these types of systems were originally developed for use as permanent monitoring networks in operating mines and quarries, monitoring professionals are increasingly benefiting from the technology on temporary building projects that have typically been the realm of attended monitoring strategies. Globally, this has emerged as a solution to provide more timely access to data for stakeholders, and to minimize the legal exposure from multiple violations of vibration limits. As this trend is likely to continue, the regulated vibration control industry is likely to see a continued shift in technology development to leverage wireless networks and the Internet to continue to improve data transfer, archiving and distribution.

Jan 1, 2006

By R. E. Morgan

This publication presents abstracts of articles and investigations pertaining to the utilization of fly ash. The terms "fly ash" and "flue. ash," as' used in most of the papers, refer to the ash from pulverized-coal firing collected by electrostatic precipitators or mechanical collectors. Several investigators do not define the material on which they report beyond calling it fly ash, but they probably refer to the fine material resulting from burning pulverized coal. A few of the papers report on investigations involving not only the use of fly ash but boiler slag as well. These can be identified by the title of the articles. Bibliographical information and the abstracts are arranged according to the date the papers were published, with the most recent listed first. With the continually increasing use of pulverized-coal firing, profitable disposal of the fly ash is becoming a problem of greater importance to many utility and industrial companies. Also, in recent years, the public demand for cleaner air, and the more highly efficient fly-ash collectors available have resulted in the collection of a greater percentage of the fly ash produced. The solution to better utilization of fly ash has, therefore, been the object of research for some years.

Jan 1, 1952

By G. L. Oldright

This paper is the fourth of a series of preliminary papers on smelting in the lead blast furnace.4 The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation and to correlate these conditions with operating factors, furnace behavior, and metallurgical losses. ACKNOWLEDGMENTS The authors wish to express their appreciation to the management of the International Smelting Co. at Tooele, Utah, for their whole-hearted cooperation in this investigation.

Jan 1, 1929

By S. Bellec, A. Berton

"Usually, steady state mass balances are used for the design of mineral processing plants. However, this tool does not take into account the impact of process inputs variability nor does it evaluate process transient behaviours between stationary states, such as mill start-up and shutdown. The use of advanced simulations enables the integration of dynamic behaviours in process design decision-making by highlighting situations that are undetectable by using only steady state mass balances. Applying these simulation tools to brown field projects allows the simulator performances to be calibrated and validated on actual plant data before it is used as a prediction tool for the modified plant.Three (3) simulators were implemented at the design stage of a major upgrade project for an ore processing plant in order to assess process behaviours under different production scenarios. These simulators were built to evaluate the impacts on major elements such as mine production, ore stockpile, concentrator production as well as water demand. A validation of individual equipment models was performed whenever sufficient measured data was available. The simulators were then used to study the impact of ore variability (grade, hardness, throughput), to assess day-to-day production special events, and to evaluate the true stockpiles live capacity.The use of a stochastic simulator for equipment sizing allowed a more precise sizing of many pieces of equipment and avoided important expenses in the fresh water pumping system. The dynamic simulator also confirmed that the water in place system would suffice, even in the most demanding production scenario. Finally, the stockpile simulator allowed an important production bottleneck to be quantified and then made possible the assessment of various practical solutions for the stockpiling-reclaiming issues.Post start-up, process data underlines the fact that using advanced simulation tools was useful to mitigate process-related risks associated to the plant expansion, showing generally accurate prediction and adequate equipment sizing, leading to smooth process commissioning. The presented methods are part of what is now routine in Soutex’s participation in both greenfield and brownfield projects."

Jan 1, 2015

Possibilities for Flotation Acoustics Monitoring - A Review

Sep 13, 2010

By Laurence G. Britton

Accurate flammability and ignitability data for chemicals form the cornerstone of procedures used to assess the hazards associated with commercial chemical production and use. Since 1967 the ASTM E27 Committee on the Hazard Potential of Chemicals has issued numerous, widely used consensus standards dealing with diverse testing and predictive procedures used to obtain relevant chemical hazard properties. The decision to issue a standard rests solely with the membership, which consists of representatives from industry, testing laboratories, consulting firms, government, academia, and instrument suppliers. Consequently, the procedures are automatically relevant, timely, and widely applicable. The purpose of this paper is to highlight some of the widely used standards, complemented with hypothetical but relevant examples describing the testing strategy, interpretation, and application of the results. A further goal of this paper is to encourage participation in the consensus standards development process. The paper is published in two parts. The first part (in the preceding issue of Process Safety Progress) dealt with the E27 standards pertaining to thermodynamics, thermal stability, and chemical compatibility. The second part, published here, focuses on the flammability, ignitability, and explosibility of fuel and air mixtures. © 2005 American Institute of Chemical Engineers Process Saf Prog 24: 12?28, 2005

Jan 1, 2005

By Dale Preece

A carefully designed and controlled in-place destruction experiment was performed on a concrete bunker buried in 4.27 m (14 ft.) of soil. The objective was to determine if the explosive charges would collapse the structure in-place without requiring mechanical excavation. Collapse of the buried structure was first attempted by drilling holes in the soil and placing four 13.38 Kg (29.5 lb) Comp B explosive charges at a depth of 2.13 m (6.7 ft.). The configuration of the charges when detonated was 2.13 m (6.7 ft.) off the top of the concrete roof and 3.66 m (12 ft.) apart in a square pattern. Detonation of these charges created a crater ~4.88 m (16 ft.) in diameter and 2.13 m (6.7 ft.) deep, leaving ~2.13 m (6.7 ft.) of soil covering. Very limited spalling occurred on the ceiling of the concrete structure as a result of detonating these four charges. The second attempt to collapse the structure consisted of placing another single 13.38 Kg (29.5 lb) charge, identical to the first four, near the geometrical center of the bunker roof. This charge was detonated in the soil cover 100 to 200 mm (4 to 8 in.) above the reinforced concrete roof, collapsing it. Due to the collapsed roof and remaining soil cover, the structure had been collapsed in place, requiring no further demolition.

Jan 1, 2006

The plant and processing site at Porgera has been built on a levelled mudstone ridge about lkm E of the mine. Excavation of 7xl06m3 of soil and rock was necessary to achieve the required area. The exposed mudstone belongs to the Chico Formation and is weak, sheared and readily breaks down by slaking upon exposure. Tectonic uplift and subsequent erosion have produced the present landscape of narrow bedrock ridges, with deep colluvium in the incised valleys. The deep excavation to a maximum of 60m, has rapidly unloaded the mudstone, and subsequent stress relief has caused rebound and dilation of the material. The processes of pore pressure equilibration, softening, progressive failure and loosening, combine to deteriorate the newly exposed rock mass. These processes are commonly associated with pre-existing shear surfaces, fissures and a

Jan 1, 1991

By W. Scheetz

The Brewer Gold Mine is an open-pit, heap leach operation that processes about 122 kt/m (135,000 stpm). The mine is operated by Brewer Gold Inc., a subsidiary of Westmont Mining Inc., and is located near Jefferson, SC, about 80 km (50 miles) southeast of Charlotte, NC and 80 km (50 miles) northeast of Columbia, SC (Fig. 1). All of the ore to date has been produced from a breccia body of hydrothermal origin and a related smaller body of fault-controlled ore, known as the B-6. Reserves at the time the mine commenced production were 4.6 Mt (5.1 million st) grading 1.4 g/t (0.042 oz per st) gold. History Although some reports of a pre-Revolution War shaft at the Brewer are in the literature (Lieber, 1856, Nitze and Wilkens, 1897), gold was first produced in earnest from the Brewer Mine in 1828. Production occurred primarily from placer deposits south of the present mine workings. Lieber noted in 1856 that “every branch, gulch, ravine or even declivity of the main hill has been washed and rewashed.”

Jan 1, 1991

By Tyler R. J

Methylene blue dye adsorbs on chalcopyrite concentrates slurried in aqueous solution. Saturation adsorption can be achieved within about 24 hours for dye equilibrium concentrations greater than about 10-5 M. The dsorption coverage is obtained from a measurement of the' colour change of the solution. Comparison with BET measurement of the concentrate surface area shows that 2.4 ± 0.1 µmol of methylene blue are adsorbed per square metre of surface accessible to the dye cation. The procedure described can be used as a single-point measurement and values for the surface area can be otained to within about 10 per cent with inexpensive instrumentation.

Jan 1, 1979

By William D. Hissem

For those blasthole applications which require the use of holes ranging from 1” to 5.5” in diameter, the use of top hammer drills has been the equipment of choice for several generations of drillers. Pneumatic compressed air and hydraulic compressed oil systems represent the primary technologies which are available to the drilling practitioner. While both employ the same operating principals, the characteristics of performance, cost, and reliability can be markedly different between technologies and manufacturers.

Jan 1, 1998

By Francis Foley

INTRODUCTION DURING the summer of 1919, the late Dr. Henry M. Howe, then Chairman of the Division of Engineering of the National Research Council, organized a committee to obtain a better insight into the behavior of carbon steels under the influence of various treatments by a proper control of the time and temperature factors. During part of 1919 and 1920, work in connection with this investigation was carried on at Dr: Howe's laboratory at Bedford Hills, N. Y. During 1921 there was an enforced hiatus in the work, occasioned by the illness which resulted in Dr. Howe's death in 1922. At that time one of the present authors compiled the results of the work which had been done and this was published in 1923.1 Following the publication of this work, it seemed desirable to carry on in the same manner an investigation of steel of C 0.75 per cent., which steel had not been as fully treated as had the other steels of C 0.34 and 0.52 per cent., used in the published work. Furthermore, certain unusual results have been obtained in the treatment of C 0.52 per cent. steel by quenching and drawing, and repetition of this part of the work seemed advisable. This has been done during the past year at the School of Mines and Metallurgy of the University of Missouri at Rolla, Mo., by a cooperative undertaking of the School and the Bureau of Mines, working in conjunction with the Committee on Heat Treatment of Carbon Steels of the National Research Council. The present paper is a report of the results obtained in this work.

Jan 2, 1926

By D. F. Hewett

CONTENTS PAGE Introduction 1 Geologic features of eastern Oregon 2 Geology of the Sumpter quadrangle 2 Rocks older than the ore deposits 3 Rocks younger than the ore deposits 8 Lodes of the Sumpter quadrangle 8 Areal distribution 8 Geologic distribution 9 Major features of the veins 9 Mineralogy and texture of the veins 13 Ore deposits zonally disposed around the Bald Mountain batholith . . . . 13 Summary of mineralogy and texture 32 Zonal relations 33 Ore deposits zonally disposed around Greenhorn Mountain batholith . . . 36 Zonal relations 37 Relation of textural features to zonal arrangement of veins 37 Summary of zonal relations 38 Comparison with similar districts 39 Outlook for the district 40 INTRODUCTION IN an earlier report on the Sumpter quadrangle1 it was briefly stated that the quartz lodes of that region might be separated into several groups or belts on the basis of the kind and abundance of the minerals of which they are composed, and that these belts were disposed as areal zones around the principal intrusive mass of the region. When the opportunity to revisit the region was offered in 1929, as a result of a cooperative agreement between the State Mining Board of Oregon and the United States Geological Survey, it seemed advisable to pay particular attention to this feature of the lodes, in the hope that if the idea of zonal relations was confirmed it might serve as a guide in exploitation.

Jan 1, 1931

The objective of this handbook is to provide the inspector with guidance for recognizing hazards from inhalation contaminants in above ground work areas of underground and surface metal and nonmetal mining and processing facilities and evaluating these hazards by collecting samples or making field determinations and interpreting the analytical results. Portions of the handbook that should prove most useful to the inspectors include a survey check list, rules for determining if sampling is required, list of most frequently encountered contaminants, list of candidate contaminants and their sampling conditions, interpretation of results, and a procedure for a health and safety inspection.

Jan 1, 2011

By Woodcock J. T

When an aqueous suspension of pyrite and manganese ore reacts with oxygen, manganese is dissolved by the ferrous sulphate and sulphuric acid produced by the oxidation of pyrite. The kinetics of certain steps in the overall reaction were studied. A rate equation for the oxidation of ferrous sulphate by gaseous oxygen was derived for the temperature range from 1000 to 200° C. An exact rate equation for the production of ferrous ion from pyrite could not be established but it was shown that the temperature, oxygen pressure, pyrite surface area, and the reduction of ferric ion by pyrite are important. A rate equation was derived for the reaction of manganese dioxide with ferrous sulphate. A major facfor controlling the rate was whether or not ferric oxide was formed by hydrolysis at the manganese dioxide surface.It was shown that if hydrolysis was prevented the factor cpntrolling the rate of the overall reaction ,was the rate of production of ferrous ion, and little ferrous ion was oxidised by oxygen. When hydrolysis of iron did occur, the overall rate was not a simplefunction of anyone factor and much ferrous ion was wasted by oxidation with oxygen.INTRODUCTIONIn another paper (Cornelius and Woodcock, 1958) the results of the reaction of an aqueous suspension of a manganese ore and pyrite with oxygen are reported. It is shown that the ferrous ion and sulphuric acid generated in situ by the oxidation of pyrite, dissolves manganese as manganous sulphate. To obtain a better understanding of the process as a whole, the kinetics of certain steps in the overall reaction were studied.When an aqueous suspension of a manganese ore and pyrite reacts with oxygen, the overall reaction may be conventionally represented by equation (1) (Cornelius and Woodcock, 1958).2Mn02 + 2FeSz + 6i02 + 2HzO= 2MnS04 + 2H2S04+ F'ez03 ... , .. (1)

Jan 1, 1958