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By Donald W. Mitchell

Certification tests for urethane-foam systems and techniques for apply-ing foam safely in mines are described. Fire hazard from foam exists if flame propagates beyond the ignition source or penetrates the foam. Foam that passes the certification tests can be applied on stoppings, continuous sections of ribs of relatively wide passageways (with no foam on the roof), short sections of roof such as overcasts, roof cavities, and intersections (with no foam on the ribs), and between buntons on one wall of a shaft. Foam on the ribs and adjoining roof presents a fire hazard. Stoppings covered with foam passing the certification tests are resistant to penetration of heat, flame, and smoke than similar stopping without foam. Flame propagation can be arrested by water sprays. Spontaneous ignition of foam can be prevented.

Jan 1, 1966

By A. K. Verma

Several longwall faces in India have collapsed due to adverse geological conditions and/or inadequate capacity of powered supports. Thus it is imperative to access the capacity of a powered support and its interaction at longwall faces of varying geomining conditions in advance with lots of confidence. To achieve this, an index has been developed to ascertain the front leg pressure (FLP) of chock-shield support and roof-to-floor convergence (RFC) at longwall faces. The index called ?Longwall Face Stability Index? (LFSI) has been developed using statistics and Finite Element Modelling (FEM). The front leg pressure (FLP) and roof-to-floor convergence (RFC) predicted from the LFSI are validated with the field monitored data from two longwall panels. In this study, an attempt is also made to incorporate various geomining conditions into the finite element models typical of longwall mining practice. The index has taken into account the wide variations of geomining parameters like thickness, young?s modulus and friction angle of main roof (small, large), coal type (soft, hard), powered support capacity, and depth of coal seam. Thus, LFSI can be thought of as an index representing combined effect of roof type, geomining conditions and powered support capacity.

Jan 1, 2008

By G. Bonifazi

Mining activities belong to human history, they are lost in the mists of time. They usually impact on large portions of the territory, both directly (exploitation areas and logistic activities directly related to exploitation) and indirectly (exploited material handling, processing and storage areas). As a result, at the end of mine life cycle, dismissed areas usually cannot be directly re-utilized without efficient and well addressed rehabilitation actions. Main goal of the proposed approach was to analyze the results obtained when a set of procedures, based on the collection and the analysis of remote sensed data, is developed to evaluate the effect of rehabilitation of land contaminated by extractive industry activities and to perform a monitoring and registration of the environmental impact of such operations by the application and the integration of modern information technologies, as Earth Observation (EO) and Geographic Information Systems (GIS). The study was developed in the framework of the EU-Asia program of the European union (EXTRACT-IT Project-Contract No: CN/ASIA IT&C/006 (89870): Application of Information Technologies for the sustainable management of Extractive industry activities) and it was addressed to three different dismissed mine areas in India, Thailand and China, respectively. The results, in terms of methodologies selected, strategies applied and results obtained, are described with particular reference to Fuxin coal mine area in China.

Jan 1, 2014

By D. C. Dahlin

To identify and characterize potential domestic chromium resources, the Bureau of Mines investigated podifom chromite deposits along the Border Ranges Fault in southern Alaska. Part 1 of this two-part report describes an extensive field investigation and preliminary resource evaluation studies by the Bureau's Alaska Field Operations Center. This paper, part 2, describes the mineralogy of 38 samples that were collected from low-grade deposits in the Chugach Mountains, on the Kenai Peninsula, and on Kodiak Island, and presents the results of laboratory batch beneficiation tests designed to concentrate the chromite. The samples are peridotites and chromites that consist primarily of variable amounts of chromite, olivine, and serpentine. They were beneficiated by a sequence of grinding, sizing, and gravity concentration operations. Twenty-four high-chromium or marginal high-chromium chromite concentrates, six high-iron or marginal high-iron chromite concentrates, and five submarginal concentrates were produced with chromium recoveries that ranged from 37 to 95 pct. Three very low-grade samples were not beneficiated. These results indicate that several of the de- posits may be significant chromium resources, Potential precious metals association with the chromite was also investigated. Analysis of these samples indicates that the chromite deposits are not good platinum sources.

Jan 1, 1985

By K. C. Dean

Changes in the types of materials used for the construction of recent automobile models have occasioned a review of the continued applicability of current recycling techniques. Plastics are being used increasingly in late model cars. To evaluate the changes occurring, a 1972 Mercury Montego, furnished by the Ford Motor Co., was completely dismantled and analyzed, and the composition was compared with that of a composite automobile from 15 vehicles ranging in date of manufacture from 1954 to 1965 and designated as a circa 1960 model. The composite vehicle contained about 26 pounds of plastics, while the 1972 model contained over four times that quantity. The increasing use of plastics in automobiles suggests that research to improve the economic potentiality of plastics recycling is warranted.

Jan 1, 1974

By D. E. G. Maschmeyer

The operation of the pilot plant for the S-C Copper Process during 1976 has provided the basic data for the design of a commercial-scale plant. This paper introduces the commercial aspects of the S-C Copper Process through the presentation of a process flow diagram, a schematic flow diagram and basic design parameters for 75,000 tonnes per year (tpy) copper rod production from chalcopyrite concentrate. Basic operating requirements are outlined and a preliminary estimate of operating and capital costs for a Western Canadian location are summarized. The results have been compared with a modern smelter/electrorefinery to highlight the advantages and disadvantages of these two alternatives and to show why the new S-C Copper Process technology should be of interest to the copper industry.

Jan 1, 1978

By Arthur V. Corry

GOLD was discovered in Alder Gulch, Virginia. City, Mont., on May 26, 1863. In a short time some 6000 people flocked to the new discovery, and on the banks of Alder Gulch six settlements sprang into existence, the principal one, Virginia City, alone surviving. This town today has a population of 800, and is the county seat of Madison County. It is estimated that between forty and fifty million dollars in gold was produced up to 1904. Virginia City is situated at the mouth of Alder Creek where that stream leaves the narrow canyon that cuts the steep foothills flanking Old Baldy Mountain, elevation 9572 ft., 12 mi. south. Virginia City itself is 5700 ft. above sea level.

Jan 1, 1936

By N. M. Stubina, P. J. Lind

Barrick Gold is in the process of building several new mines and implementing new processes at existing mines for which metallurgical technology is of key importance. The roles of the company's Strategic Technology Solutions team and the Barrick Technology Centre are discussed within the context of their responsibilities within Barrick's Operations Support group. The paper will present an overview of the development of the technology centre from the former Placer Dome Research Centre to its current form supporting strategic technology, capital projects, and operating sites. Novel approaches to research and development will be presented as well as an overview of some of the technologies developed from bench-scale to pilot-scale, and beyond.

Jan 1, 2011

By R. A. May, P. J. Brooks, W. M. Smith

"Neill and Gunter Limited (NGL) has prepared a preliminary design and a cost estimate for a ferric chloride leach plant to recover copper, lead, zinc, and silver from a typical complex sulphide ore. This plant design is specifically intended to treat unconcentrated ground ore (flotation feed), but can be readily adapted to treat bulk concentrates. Samples of ground ore and bulk concentrate were obtained from Heath Steele Mines, Miramichi, New Brunswick, laboratory testing, and preliminary process flow sheet preparation was carried out by the Research and Productivity Council in Fredericton, New Brunswick. Approximately thirty drawings have been produced, including process and equipment flowsheets, process piping and instrumentation drawings, and preliminary general arrangements. Preliminary capital and operating cost estimates were prepared for a plant that would treat 1000 t/d of crushed and ground ore to produce about 30 000 tpy of zinc. Capital and operating cost estimates were also projected for plants up to 4000 t/d of processed ore. Recoveries of 99% for zinc, 98% for lead, and 96% for copper were achieved in laboratory tests on unconcentrated ore. These recoveries were higher than the overall recoveries obtained from bulk concentrate, yielding approximately 10% more revenue.A 1000 tonne per day plant was determined to have a low return on investment, however, depending on the size and type of mining operations employed and the FCL plant throughput. DCF-ROI projections of 20% to over 30% were calculated for 100% equity financed “green field” mine, mill and FCL plant operations of 2000 t/d and higher"

Jan 1, 1997

By L Zhang

The Chinese coal industry is the largest coal producer in the world. The total production in I995 was 1.28 bnt. On the way towards introducing a market economic system, this mature industry is facing major challenges. The main problems are a large surplus of manpower, shortage of current assets and capital, low productivity, high casualties and a huge deficit. This paper discusses the present situation and the future developments in the Chinese coal industry. The current policy can be stated as ‘rapidly developing the state collieries and improving the village and private mines; integrated development to achieve an economic operating scale and encouraging a diversified economy; rapidly exploiting and developing in the North west and South west; promoting productivity and efficiency; welcoming multi-sources and types of investment; setting up coal exchange markets; and the careful control of resources and the environment'.

Jan 11, 1996

By G. Ferrara

The paper describes the new design criteria and control strategies for multi-density dense medium separation (DMS) circuits. The role of the multi-density separation is discussed, and it is emphasized that for many processing problems -related to minerals and coals -it may be very important to perform two or more cuts at different densities in order to obtain a remarkable improvement in quality of products, process efficiency and economy. The two-density separation by dense medium cyclones was generally performed using two dense medium plants in sequence. In contrast to the former technology, the multi-density separation can now be performed by using a single medium circuit composed of different interconnected medium sumps. The sumps, one for each density, are fed with different medium streams selected according to their density, size composition and content in non-magnetic contaminant in such a way that the rheological properties of the media are optimized. This new technology is based on dynamic systems to density the medium, on the size-density segregation of the medium in the cyclones and separating devices and on accurate control systems for the density, viscosity and stability of the dense media of the different sumps. The present paper reports on the theoretical basis for the new, advanced medium circuits and on the systems for the control of the densities and of the rheological properties of the dense media. A typical circuit for a two-density separation is also described, and some industrial applications reported and discussed.

Jan 1, 1994

By Cyrus W. Field

Metalliferous sediments constitute an important component of the sedimentary veneer that overlies basaltic oceanic crust of the Nazca Plate and elsewhere. Although first collected more than one century ago near the East Pacific Rise during the Challenger Expedition and recognized for their anomalously high content of Fe and Mn, occurring as very fine-grained, yellow-orange, oxides, hydroxides, and oxyhydroxides, it was not until the more detailed studies of Bostrom and Peterson (1966) that their geologic significance and concentrations of other transition metals were fully appreciated. The Nazca Plate is a dynamic lithospheric unit bordered by the Peru-Chile trench and the East Pacific Rise to the east and west, and by the Galapagos Rift and the Chile Rise to the north and south (Fig. 1). Samples employed in this study were taken from piston core recovered from the Nazca Plate (Fig. 2), D. S. D. P. drill core from the northeast Pacific (Dymond and others, 1973), ferromanganese nodules from dredge-haul s at several locations, and from hydrothermal mineral deposits of the Andes. Our efforts have been largely sponsored by the National Science Foundation through its International Decade of Ocean Exploration Pro- gram. The metalliferous fraction of these sediments is widespread, but generally small. Sedimentation is dominated by biogenic silica in the equatorial latitudes, terrigenous debris adjacent to the South American Continent, and by biogenic carbonate elsewhere, except at depths below 3500 m in the central and northwest parts of the Nazca Plate near the East Pacific Rise. Contributions of these distinctive sediment types are shown by the distributions of Si02, A1203, and CaC03 given in Figure 3.

Jan 1, 1982

By F. McCarthy, W. Zhang, R. McDonald

"The processing of nickel laterites has been a topic of major interest at CSIRO for almost twenty years. During this period CSIRO has collaborated with other researchers and industry in developing a better understanding of existing processes and been actively involved in testing/developing new beneficiation and process options for these ores. The current paper summarises the results of selected studies and highlights improvements that have been achieved. Key topics to be discussed include enhancements in the mineralogical characterisation, beneficiation approaches, improvements in the understanding and application of leaching technologies, the development of synergistic solvent extraction (SSX) for the recovery of nickel/cobalt from laterite leach liquors and the collaborative development of the Direct Nickel process. Future opportunities and key research questions will be briefly examined.INTRODUCTION Nickel laterite ores comprise a significant resource in Australia and according to United States Geological Survey data nearly a quarter of world reserves are located there (USGS, 2016). More specifically, around 95% of Australian nickel resources (laterite and sulfide) are located in Western Australia (Australian Government, 2017). Given the recent closure of Queensland Nickel, essentially all of Australian nickel production occurs in Western Australia and the primary producers of processed nickel products include Nickel West (Kwinana) with ~84,000 t saleable nickel metal in 2016 (BHP Billiton, 2017), Minara Resources (Murrin Murrin) with 46,700 t nickel metal produced in 2015 (Glencore Australia, 2017), and First Quantum Minerals Ltd (Ravensthorpe) who sold 25,882 t nickel as mixed hydroxide product in 2016 (First Quantum Minerals, 2017). The total sales of nickel from Western Australia in the 2015-16 financial year were 175,722 t. The study of nickel laterites at CSIRO recommenced at the time second generation High Pressure Acid Leaching (HPAL) plants were being commissioned at Bulong, Cawse and Murrin Murrin in the late 1990’s. A combination of technical and engineering issues meant that the ramp-up times at these operations were slower than expected and the outcomes resulting from the attendant problems are well documented (e.g. Griffin & Becker, 2000; Reid & Barnett, 2002; O’Callaghan, 2003) while the issues faced at the BHP-Billiton-built Ravensthorpe plant have been addressed by the current owners of this project, First Quantum Minerals Ltd (Piper, 2012)."

Jan 1, 2017

Incidental to the progress of a geological survey of the Kalgoorlie goldfield during 1927 - 1928 a number of specimens of telluride minerals were obtained, chiefly with the help of Mr F G Brinsden, general manager of the South Kalgoorlie mine, and Mr Ernest Williams, general manager of the Boulder Perseverance mine. This collection was supplemented by a number of small specimens, including the rare copper telluride, which were collected and preserved from the Kalgoorlie mine by Mr A E Paton, and also by a few miscellaneous specimens from the collection of MrS F C Cook, of the Palace Hotel, Kalgoorlie.An extensive knowledge of the rare tellurium-bearing minerals was compiled during the last century from occurrences in Transylvania and Colorado. The recognition of different species has been based on chemical analyses and crystallographic measurements. In a few species there has been an absence of crystalline form, and these, together with the discoveries in this century of rickardite and 'weissite', muthmannite and empressite, have depended chiefly on the chemical analysis for identification. On the other hand, the crystalline form of nagyagite and stiitzite has been described in detail, while their precise chemical formulae were doubtfully defined.The announcement of the occurrence of tellurides at Kalgoorlie by A G Holroyd in the Kalgoorlie Mine on 29 May 1896, followed by their discovery in comparative abundance, stimulated the further study of these minerals. In this locality there is a general absence of well-formed crystals, and the knowledge gained has been confined to the record and description of previously known, but exceedingly rare, species.No new species has been recorded, but the intimate association of various species resulted in early description of two supposedly new species, kalgoorlite and coolgardite. These have been discredited since the investigation by L J Spencer in 1903, based on a collection of specimens donated to the British Museum.Spencer's list of species at Kalgoorlie comprises calaverite, sylvanite (or krennnerite), petzite, coloradoite, 'and altaite, and does not include hessite, previously mentioned by Krusch. In 1912 melonite and a copper telluride were added by J A Thomson and the presence of hessite confirmed. In 1912 there also appeared a full and detailed account by E S Simpson on behalf of the WA Geological Survey, which embraced his earlier notes on the tellurides, and which represents the state of our knowledge of the Kalgoorlie minerals, practically as far as can be attained without the use of the reflecting microscope.The position has been stationary for about 18 years, and it was thought. that the best use to which the present collection of tellurides could be devoted was an attempt by mineragraphic methods to study the mineral relationships, not only of the tellurides among themselves, but also to gold and other associated minerals. The precise mineral content and relationships become a factor of added importance with the development of flotation methods of treatment at Kalgoorlie.Moreover, the study would supplement the description of the ore deposits of the Boulder Belt that has recently been published.

Jan 1, 1994

By Y. B. Zhu

Soil reconstruction and improvement trials and vegetation experiment is carried out at Shuilong-shan acid rock waste dumps at Dexing Copper Mine in China. pH value, Cu2+, Pb2+, Zn2+, etc. concentration in acid rock drainage (ARD) is also monitored every month since 2005. The results of experiment show that: Lime and topsoil stripped from open-pit is appropriated soil improvement material. Full cover soil improvement method is suitable for flat area, contour soil improvement method and hole soil improvement method is appropriate for slope area. The optimal plant species is ligustrum lucidum Ait,Lespedeza bicolor, Paspalum notatum, Veti-veria zizanioides, Eragrostis pilos and Neyraudia reynaudian. It is the best for Arbor, shrub and grass to be arranged in pairs or groups in order to remold optimal landscape. Pilot sites, covering 3ha, is established. Vegetation coverage reaches 90% in platform area, 40% in slope area. pH value in ARD increased slightly, Cu2+, Pb2+ concentration in ARD decreased, Zn2+ concentration in ARD decreased and varied slightly.

Jan 1, 2014

The objectives of mining grade control are presented and examples of the techniques used in various open pit and underground mines are used to define the attributes of good grade control. Reasons are discussed for the success of various improved practices. The progressive development of grade control is presented and the balance between quantitative and qualitative data is analysed. The skills and resources required for grade control on mine sites that are using best practice are also presented. A number of problems in grade control have been solved recently however there are still issues that need to be addressed. Examination of the grade control process frequently stops after sample quality has been examined. There is much more beyond this that can now be optimised using conditional simulation models. Other future directions of mining grade control are also suggested. An extensive bibliography of published papers on grade control is included that will be maintained and updated on a website.

Jan 1, 2000

By Joseph J. Wallace

1. The Investigation shows that there are six coal beds of major importance in McDowell County from the standpoint of present production - Pocahontas No. 3, Pocahontas No. 4, Pocahontas No. 5, Sewall, Beckley, and Pochontas No. 6 - and five beds of minor importance - Iaeger, Douglas, Welch, Pocahontas, No. 9, and Eagle. The Pocahontas No. 3 bed contains the largest remaining, known reserves. 2. Known measured, and indicated reserves in all beds, based on a minimum thickness of 174 inches and on 1,800 tons per acre-foot of coal in place, are estimated at 2,217 Trillion short tons as of January 1, 1951. Of this total, 1,731 million short tons are in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager to make an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these area, such reserves should be added to he total estimated reserves.

Jan 1, 1952

By D. Beneteau, L. Feldman, D. Milne, A. Hyett, G. Snell

"Behaviour of rebar bolts subjected to combined shear and bending in underground potash mining applications is not well understood. An experimental investigation compared load applied to resin-grouted No. 25 metric rebar to theoretical load, calculated using elastic bending theory. Distributed optical sensing (fibre optic) technology allowed axial strain measurements at 1.25 mm increments along the length of rebar. Experimental procedure, data processing methods, and equipment improvements are needed for field applications of optical sensing technology. Goals were to adopt procedures for instrumenting rebar bolts, conduct tests, and develop data interpretation methods to measure field deformations and loads. ¦ KEYWORDS Fibre optic, Potash mine, Rebar bolts, Transverse load testing RÉSUMÉ On appréhende encore mal le comportement des boulons d’ancrage pour barres d’armature soumis au cisaillement et au cintrage pour un usage dans des mines de potasse souterraines. Une étude expérimentale compare la charge appliquée aux barres d’armature de diamètre n° 25 (25 mm en mesure métrique) enduites de résine époxy à la charge théorique, calculée à l’aide de la théorie de la flexion élastique. La technologie de détection optique distribuée (fibre optique) a permis d’effectuer des mesures de la contrainte axiale à des différentielles de 1,25 mm sur toute la longueur de la barre d’armature. Pour des applications sur le terrain de la technologie de détection optique, il faut envisager une procédure expérimentale, des méthodes de traitement de données et une amélioration de l’équipement. Les objectifs établis consistent à adopter des procédures d’instrumentation des boulons d’ancrage pour barres d’armature, à effectuer des essais et à mettre au point des méthodes d’interprétation des données pour mesurer les déformations et les charges sur le site. ¦ MOTS CLÉS boulons d’ancrage pour barres d’armature, essai par charge transversale, fibre optique, mine de potasseINTRODUCTION Resin grouted rebar bolts are commonly used in potash mines in the province of Saskatchewan, Canada, in areas where shear deformation is observed in the rock, or where potentially unstable ground is present, including locations such as clay seams. Opportunities to observe deformations of rebar, as shown in Figure 1, are rare because it is unusual in underground potash mining to excavate supported ground. In this situation, a block of potash containing a rebar bolt had failed."

Jan 1, 2019

By Lin Yang, Minjun Tang, Shuishi Liu, Jianfeng Zhou, Linjiang Qing, Xiaolei Song, Yufeng Guo, Tao Jiang

"The dynamics of oolitic hematite magnetic roasting was studied. The results show that oolitic hematite magnetic roasting was controlled by the internal diffusion, and the diffusion coefficient was 9.018x10-7 m2·s-1when the oolitic hematite was roasted at 650°C. Magnetic susceptibility improves when temperature increases and roasted time prolonges under the condition of roasting at 650°Cfor 50min, with the magnetic susceptibility is 39.88%. CaF2 and Na2C03 can significantly improve the magnetic susceptibility at the same roasting condition, and the magnetic susceptibility was 63.35% and 57.99% respectively, thus the reduction of oolimic hematite was promoted.IntroductionWith the continual depletion of free-milling iron ores and its rising price, developing the abundant resources of oolitic hematite has become one of the main research areas. The oolitic hematite accounts for 10% of China's iron ore reserve, and it also accounts for 30% of red ore reserve in China [1]. In order to exploit the oolitic hematite, there are many beneficiation research methods, including fine grinding/selective flocculation/high intensity magnetic separation or flotation, high-gradient magnetic separation, low intensity magnetic separation/high intensity magnetic separation/reverse flotation, chloridizing roasting/acid pickling, magnetic roasting/leaching process etc [2]. However, the oolitic hematite is easy to slim and the valuable mineral is covered by the slim, because of the tiny granule of value mineral, then the ooides are formed due to the state of layer morphology formed by iron ore and ganaue minerals [3, 4]. Fairly good separation indexes were hard to be obtained by traditional separation due to its structural features, so the magnetic property of the iron minerals will be changed with the use of the magnetic roasting [5, 6], which result in hematite variably altered to magnetite and simplified technological process so that a good separation indexes will be obtained by using the low intensity magnetic separation. Therefore, in order to provide theoretical direction of how to use the oolitic hematite effectively through the magnetic roasting, the oolitic hematite of GuiZhou province was studied, which emphasized on researching the dynamics of oolitic hematite magnetic roasting."

Jan 1, 2013

Process variables in flotation circuits are outlined with a view to producing mathematical models of circuits. The nature of the kinetics of flotation are discussed and the effect of process variables on the kinetics considered. An approach for a possible model is briefly outlined.

Jan 1, 1971