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By James A. L. White

Although the quantity of native sulphur associated with volcanism is large, production from such deposits represents only a very small percentage of total world production, This paper describes the location of the known deposits, the typical geology of these deposits and the nature of the sulphur mineralization. Methods of treatment are discussed and some comments are offered on the economic position of these occurences in world sulphur markets.

Jan 1, 1967

By Hasan Kolayli

Zeolites are common secondary components of a variety of igneous rocks. However it is extremely rare to reach such abundances to form a rock. An unusual rock composed almost entirely of natrolite, a zeolite mineral, has been discovered ; in a mountainous terrain called the Kop mountain range in the eastern Turkey. In the region, country rocks are essentially metamorphic rocks. These unique rocks are resulted through metasomatic changes acted on microdioritic and andesitic parent rocks occurring generally as dikes and stocks in the country rocks consisting chiefly of serpentinized harzburgites. These metasomatic rocks are investigated with respect to their mineralogical, petrographical, and geochemical characteristics. These products consisting dominantly of natrolite are termed "natrolitite" and those containing additional pargasite, an amphibol mineral, are termed "pargasite-bearing natrolitite or pargasitic natrolitite ". The dikes and stocks show concentric zoning, each of which has distinct chemical and mineralogical compositions: Na2O and H2O contents show enrichment outward from the core to chill zones whereas, SiO2 and CaO show depletion. Mineralogically, plagioclase variety, abundance and chemistry change outwards from the center due to partial to complete replacement of natrolite: anorthite contents of plagioclases decrease outward, which is indicated by A1203 and CaO decrease and SiO2 and Na2O increase, showing inverse relationship with increasing natrolite content.

Jan 1, 2005

By Spencer R. Titley

Porphyry copper deposits in the southwestern Pacific area represent relative newcomers to the growing number of occurrences of this mineral deposit type. In addition to firmly establishing the importance of this region and its potential influence within the framework of world copper resources, the deposits of this region are significant from a scientific point of view because of their close relationship to the phenomena of Island Arc evolution. Since the discovery of Panguna on Bougainville in 1964, the list of prospects, proven and unproven, and developments, has grown to more than twenty and the number continues to increase. At the time of this writing, the number of prospects is imperfectly known but the following localities and numbers are fair minimum approximations: Manus (Admiralty Islands) (3); New Britain (5); New Ireland (1); Guadalcanal (2); New Guinea Highlands (6); Misima (1); and Fiji (2); Proven prospects are present in the new Guinea Highlands (2); one deposit is being developed in Test Irian, and one orebody, on Bougainville, is in production. This summary paper concerns a discussion of some of the geological characteristics of producers, developments, and prospects on the Islands of Nets Guinea, New Britain, Bougainville, Guadalcanal, and Manus. I am not aware of publishable data for Misima or Fiji. As so many variables ultimately determine whether or not a porphyry copper occurrence becomes an orebody, not the least of which is geography, this summary treats the characteristics of these occurrences which alloy; their assignment to the porphyry copper category. For purposes of this discussion, I have considered those copper occurrences which are apparently genetically related to talc-alkaline intrusions and in which the content of copper has been upgraded 50 to 100 times the Clarke for that particular host rock. Some of these occurrences are shown on Figure 1.

Jan 1, 1973

By Zoë Dugdale, Gerald Poplin, Tim Bauerle

"Fatigue presents several challenges for the mining industry. Depending on the specific occupation, daily work or operational setup on any given mine site, mining jobs can have a fair amount of labor-intensive tasks mixed with monotonous and repetitive duties. Combined with the long working hours and shift-work schedules of mining work, the prevalence of fatigue in mine workers may seem rather unsurprising.Mining is certainly not alone in facing the challenge of addressing worker fatigue. Indeed, many of the characteristics above mirror the similarities of fatigue in other industries, such as health care, aviation and security. To the extent that fatigue in mining acts like fatigue in any other industry, then any fatigue management applications, trainings, or interventions in existence can be borrowed from other industries and applied to mining in a cookie-cutter approach. However, some have argued that mining in particular is especially susceptible to increases in the prevalence of fatigue beyond the characteristics listed above due to the multifaceted combination of factors in mining environments associated with fatigue: dim lighting; limited visual acuity; hot temperatures; loud noise; highly repetitive, sustained, and monotonous tasks; shiftwork; long work hours; long commute times due to mine site remoteness; early morning awakenings; and generally poor sleep habits (Canadian Centre for Occupational Health and Safety, 2012; Legault, 2011). Legault (2011) in particular argues that it is the combination of these factors simultaneously that can make mineworkers particularly susceptible to sleep deprivation and fatigue in comparison to other industries where these factors are often not present all together. If fatigue looks and acts different in mining, as others have argued, more research is needed to determine if, how, and why worker fatigue might need to be managed differently in mining.While the burden of fatigue on the mining population has not yet been evaluated thoroughly, methods and measures of fatigue management remain a popular point of discussion. Many commercial suppliers and consultancy groups have begun to develop technologically based fatigue monitoring systems (McMillian, 2013). Some technologies can monitor vehicle operators for indicators of wakefulness, such as percent eyelid"

Jan 3, 2018

By B. Cavender

Investments in new technology are often intended to improve the production or cost performance of existing operations. The economics used to justify these projects can be flawed, however, if they do not adequately consider the potential benefits of the alterative: the fully optimized use of the facility's present equipment and personnel. While new technology can be effective, dramatic improvements in production performance can also be achieved through the rigorous application of standard industrial engineering and operations management practices. An intermediate approach may also be effective: many basic improvements In the mine or plant necessary to support new technology will be equally effective when implemented for the facility's present operators. Firms who optimize their present operations are able to save the capital and avoid the risk associated with new technology. These firms will also be able to capitalize more quickly on new technology when it is implemented.

Jan 1, 1999

By Richard E. Lounsbury

Coal mine refuse handling traditionally has been the redheaded stepchild of the industry - a problem to be ignored as much as possible. During the past few years, however, mining companies have become more aware of the potential water pollution problem associated with refuse handling and storage. Planning for refuse disposal increasingly emphasizes protection of the environment as well as economics of refuse handling. Coal companies are responding to the environmental control needs by devising new systems and adapting well-known techniques to refuse handling systems. Monterey Coal Company has operated a non-polluting refuse disposal system at its No. 1 Mine for over two years. The purpose of this paper is to describe the design considerations given to the planning of that system and the operational experience gained during its construction

Jan 1, 1973

By Gilbert Sauriol

The mining complex, which the Mines Gaspé division of Noranda Mines Limited has operated in Murdochville since 1954, includes open pit and underground mines, two mills, one leaching plant and a smelter. The under- ground mining uses predominantly a large scale room and pillar method, rooms 15 m wide, 30 m high and 300 m long being common. Ore production is effected by 4.5 m3 front-end loaders and 32-tonne trucks powered respectively by 225 and 325 kW diesels. Daily dust and gas readings show that air quality can be maintained at an acceptable level with much less ventilation than that normally specified. This paper emphasizes the point that air requirements should be based on Air Quality Standards, thus allowing an operation to benefit from favourable conditions or from improvements such as exhaust treatment, fuel alteration, etc.

Jan 1, 1983

By M. M. Hajdasinki

A project's rates of return (RORs)1, be it the internal rates return (IRRs) or one of the many IRR surrogates, frequently needs to be approximated. The success and efficiency an ROR- approximation procedure depend on the quality the approximation-initiating parameters, such as bounds or seed values (guesses). The existing approximation procedures commonly use bounds and guesses suggested by intuition rather than supported by mathematical considerations. This paper presents three mathematically founded ROR-bounding and eleven ROR-guessing approaches and examines their suitability by using examples of typical project cash-flowpatterns (CFPs). The calculated bounds and guesses not only improve the approximation efficiency, but also allow the process of the ROR discovery to be automated, thereby making it more convenient and reliable.

Jan 1, 1999

By Hans Hamrin, Bruce Kennedy

Once an ore body has been probed and outlined, and sufficient information has been collected to warrant further analysis, the important process of selecting the most appropriate method or methods for mining can begin. At this stage, the selection is preliminary only, serving as the basis for a project layout and feasibility study. Later, it may be found necessary to revise the details, but the basic principles for the ore extraction should remain a part of the final layout. With respect to the basic principles employed, relatively few mining methods are used today. For the purposes of this presentation, the principles are classified as follows: 1) For naturally supported stopes, the available methods are room-and-pillar mining and sublevel stoping. 2) For artificially supported stopes, the available methods are shrinkage stoping, cut-and-fill mining, square-set mining, and longwall mining. 3) For caving methods, the available techniques are sublevel caving and block caving. Due to the uniqueness of each ore deposit, the variations on each of these methods are nearly limitless. It is impossible to include even the major variations in this chapter; the goal of this chapter is to present the principles as a guide to the mining engineer in adapting the general methods to specific needs. The selection process described herein is intended to supply the techniques by which the candidate methods available for a given ore body can be reduced to one or two feasible approaches. The feasible approaches then can be evaluated in detail, and the particular modifications can be investigated. In describing costs and economic factors, all values herein are expressed in terms of 1978 US dollars.

Jan 1, 1982

By M. Javier

Management is a major part of sustainability research. Many different aspects of sustainability have already received significant research attention, but the management processes in mining from the perspective of their impact on society are less understood and integrated as a holistic frame. It is evident that mining technology has received major blame in past ecological disasters and major mining-induced environmental hazards, but the management-mining process has escaped unscathed. This should not have happened. Instead, the management processes should share equal blame with obsolete technology for the failure to identify and monitor potential environmental hazards before their inception of mining. We will present an emergent style of management for the future of mining. It challenges the actual ?mind-set? of mining management. It describes balance and equilibrium: physical, chemical, and biological in nature as an understanding of nature?s language, which is Geomimic along side ?the bottom line?. The goal is to minimize loss instead of maximize profits (waste design) at the design stage of mining and to develop clean technologies (nature's values) to achieve non-social environmental impacts that provide a prosperous legacy to future generations.

Jan 1, 2010

By R. E. Hucko

The goal of the U.S. Department of Energy (DOE) coal preparation R&D program is to develop technology to reduce the ash and sulfur contents of United States coals to levels such that the resultant product can be formulated into a high- quality solid or slurry fuel that could replace oil or natural gas in both new and retrofit applications. The Coal Preparation program is implemented by the Pittsburgh Energy Technology Center (PETC) and is conducted both in-house and by a cross section of industrial organizations, universities, and national laboratories.

Jan 1, 1986

By Paul Soros

Lord Robens, Chairman of the National Coal Board of England announced recently to the world press plans for construction of the largest bulk terminal in Western Europe. This should result in annual freight savings of 22.4 million dollars and between 150 and 190 million dollars of new export business. These are rather substantial amounts for any mining enterprise. Or to put it another way, opportunities to make substantial savings in the delivered price of a highly competitive commodity such as coal are few and far between. One area where such opportunities still exist is in the economical; movement of bulk materials between producer and consumer.

Jan 1, 1966

By R. E. Ray

As coal reserves at shallow depths continue to be exhausted, a number of US coal companies are developing seams previously considered too deep to mine economically. Because of increased cover load, mines operating in deeper seams face unique ground control problems. In addition, the volume of methane gas in coal beds increases with depth, and ventilation requirements are much more stringent for deep mines than for shallower mines. When the longwall mining method is wed at great depths, ventilation, ground control, and operational considerations all influence the design of longwall panels. This paper examines these influences, particularly ventilation and operational considerations, on the feasibility of two-, three-, and four-entry longwall development panels in Jim Walter Resources' four deep mines.

Jan 1, 1988

By John W. Brauns

18.1-RAILROAD JOHN W. BRAUNS Conventional railroad haulage can be employed at both open-pit or strip and underground mines-in the latter case, largely for transfer of ore from distant openings to processing plants, or processed material to loading points or docks, using standard hopper cars for bottom unloading or gondolas for rotary dumping. The major application, however, is in surface mining for moving ore and/or waste out of the pit to a crushing plant or dump. Consequently, the following will deal largely with this phase of railroad operation, though the conclusions apply equally, for the most part, to other rail-type surface haulage. In surface mining, trains consisting of a locomotive and gondola or side-dump cars suitable for loading by power shovels are used. Gondolas are restricted to hauling ore as a rotary dumper is required. Side-dump cars are more versatile, carrying both ore and waste, but because of their additional dumping mechanism they are likely to be more expensive to maintain.' Also they weigh up to twice a flat-bottom car of the same capacity and. therefore, fewer" cars can be hauled per train. Standard-gage track is most commonly used. Track systems incorporate low-quality temporary track where moves are frequent and permanent high-quality track on main lines. Rail haulage can be used alone, or in combination with other surface haulage methods, thus permitting a selection best adapted to the peculiar requirements of each mining project. 18.1.1---GENERAL APPLICABILITY, CONTROLLING PHYSICAL CONDITIONS For handling rough rock, the shovel-train system is unexcelled.' The ideal applica¬tion is in a large, but not excessively deep, open pit mine from which the coarsely blasted ore and waste must be transported over 3 mi. If. in addition, a high production rate is to he maintained, railroad haulage probably will afford a lower cost per ton transported. Grade must he relatively gentle-usually 3% uphill and 4% downhill. The greater the differences in elevation involved, the greater are the track grade space requirements; for example, a 3 c ramp out of a pit only 300 ft deep is almost 2 mi long. Main-line track locations should he selected carefully so that the number of moves during the life of the mining operation can he kept to a minimum. This applies both to the ore haulageway and that for waste. Such moves are not only expensive, but are difficult to execute without adversely affecting production rates. The large mine affords greater opportunities for judicious location of semipermanent trackage. Figs. 18-1 and 18-2 illustrate typical track layouts. The effect of terrain in considering railroad haulage is confined chiefly to the initial cost of the installation. Grade construction in mountainous territory is ap¬preciably more expensive. However, if that expense can be borne, the subsequent maintenance cost of trackage will not he much higher than in areas of low relief.

Jan 1, 1973

By Larry Taylor, Thomas Zdeb, Brian Jacobs, Dennis Jensen

Subway tunnels proposed for the Los Angeles County Metropolitan Transportation Authority (LAMTA) East Side Extension are to be excavated below the groundwater through an area of Los Angeles, California with dissolved hydrogen sulfide concentrations in excess of 200 mg/L. To address unique construction and worker safety issues, bench scale and field pilot test studies were conducted to evaluate various mitigation alternatives including in-situ oxidation by chemical injection, slurry pH adjustment to suppress H2S evolution, and chemical treatment to remove the H2S from the slurry and muck material. The results provided the basis for detailed hydrogen sulfide control specifications for the contractor.

Jan 1, 1999

By L. Zhou, L. Yuan, R. A. Thomas, D. Bahrami

The abstract emphasizes the importance of a calibrated ventilation network model for mine ventilation planning, optimization, and fire simulation. It highlights the impact of continuous airflow monitoring on improving model calibration. The paper discusses an experimental study at the Safety Research Coal Mine (SRCM) to understand the use of continuous airflow data for model improvement. It also addresses practical problems in calibration and tuning using this data, including analysis of air velocity sensor fluctuations and application of sensor location correction factors for accurate average air velocity.

Mar 7, 2022

By D. B. Buddecke

Powell Bend Mine, located in Bastrop County, Texas, is owned by the Lower Colorado River Authority (LCRA). The mine is operated under contract by the Powell Bend Mining Company (PBHC), an affiliate of Pittsburg and Midway Coal Mining Co., and produces 210,000 tons of 6500 BTU/LB lignite per year for LCRA's Fayette Power Project near La Grange, Texas. PBHC operates the surface strip mine one shift per day, five days per week with a total of nine employees; six operations/maintenance and three office/supervision. The mine's productivity in 1988 averaged 100.3 tons per manshift using an l8-cubic yard dragline to uncover the lignite. Delivered cost to LCRA, F.O.B. mine, is $6.11 per ton, which includes water control and final reclamation.

Jan 1, 1990

By F. L. Wilke

The prototype of an expert system, designed to assist layout planning of face operations, is presented. By specific combination of knowledge-based and conventional EDP techniques it has been possible to extend the known Kepner-Tregoe method up to the determination of mature layout solutions in difficult planning cases. It has been proven that the presented strategy - which can be applied to any kind of problem with similar structure - is apt to provide efficient EDP support for handling complex mining problems. Such support goes far beyond the purely numeric evaluation of envisaged alternatives.

Jan 1, 1989

By Stuart Ratcliffe, Denis Kidby

The development of Vitrokele™ Technology over the last 10 years is reviewed with reference to mine site piloting and com­mercial applications. The first mine site piloting was conducted in Australia in 1989 followed by a further six continuous site trials in Australia, Canada and the USA. These major pilot plant studies are complemented by over 50 laboratory scale batch and pilot testwork programmes. The first commercial plant using Vitrokele™ Technology was the Connemara project commissioned in Zimbabwe in 1995. Subsequent to this, three commercial scale projects have been designed using Vitrokele™ to recover precious metals, base met­als and cyanide. The various projects are discussed with relation to the differ­ing flowsheets applied to each particular case.

Jan 1, 1998

By Mahmut Altiner

Magnesium is listed as a key critical raw material in a report by the European Commission that evaluated raw materials based on supply risk versus economic importance [1]. It has extraordinary properties, such as nontoxicity, inertness, high melting point, stability, low weight, chemical resistance, electrical insulation, optical transparency, corrosion-resistant behavior and refractory nature. It is widely used in the areas of agriculture; the environment, for antibacterial and water-purification purposes; electronics; automotive; drug delivery; ceramics; construction, as filler in brick; and concrete production, in the forms of magnesium oxychloride and magnesium oxysulfate. Magnesium oxide (MgO) particles can be produced through the calcination of magnesite ore at different calcination conditions depending on the desired quality of the product, classified as fused (2,800 °C), dead-burned (>1,400 °C), hard-burned (1,000–1,400 °C), or light-burned MgO (700–1,000 °C) [2]. However, the global availability of magnesite ore is limited.