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By Carlos G. C

Geological mapping in various parts of Australia is revealing a number of regional associations of mineralizations with particular persistent stratigraphic horizons. Such associations have been found in the Broken Hill district of New South Wales, in the Nairne district of South Australia, in the Mount Isa district of Queensland, and in the Cloncurry district of Queensland. The question has arisen as to whether such mineralizations are of sedimentary origin, syngenetic with the enclosing formation, or whether they are of epigenetic origin, and reflect the selective hydrothermal mineralization of favourable beds on a regional scale.The purpose of this investigation is to test the use of sulphur-selenium ratios as an objective method of distinguishing between suphide deposits or sedimentary or supergene origin, and sulphide deposits of hydrothermal origin, with particular application to the districts mentioned. At the same time much data has been accumulated as to the selenium content of Australian sulphide ores. The possible use of sulphur-selenium ratios for this purpose was first demonstrated by Goldschmidt and his coworkers (1933; 1935), and later by Carstens (1941). Goldschmidt and Strock (1935) found that pyrite of sedimentary origin had a sulphur : selenium ratio of the order of 200,000 or more, whereas pyrite of hydrothermal origin had a sulphur: selenium ratio of 10,000 to 20,000. Carstensfound that sedimentary pyrite deposits in Norway contained less than 1 g. Se per ton, whereas hydrothermal pyrite deposits contained 20 to 30 g. per ton.

Jan 1, 1954

By Sanford J. Douglas

This publication describes a study by the Federal Bureau of Mines of devices and methods used for testing and splicing 4,160-volt and 440-volt cables and for providing ground-fault protection for 440-volt circuits, as developed and used by the electrical staff of the Tecumseh coal mine, an open-pit operation at Boonville, Ind. The testing and ground-fault devices described should find ready application in other open-pit mines, and, with suitable modifications for voltages involved, in underground mining. The devices and testing methods are based on sound engineering principles and are time-tested and economically feasible, Four devices are used: A high-voltage tester, and a low-voltage high- current tester, both for testing 4,160-volt cables; a tester for 440-volt cables; and, electronic ground-fault protective device for 440-volt cable circuits. All the cable testers and the grounding device were designed and built at the mine from standard parts. They are inexpensive, dependable, and job tested, An attempt has been made here to describe them in enough detail so that interested persons can assemble duplicate units.

Jan 1, 1960

By Dolf W. Fieldman

Most recently the geologic setting of the mineral deposits in the Silver Cliff district is described by William M. Sharp in ?Geologic Map of the Silver Cliff and Rosita Volcanic Centers, Custer County, Colorado?, (U. S. G. S. Map I- 1081). The discussion will relate only to the southern half of the Silver Cliff volcanic center and differences in geologic interpretation, which are largely structural, will be pointed out as they arise. Only the manganese/silver zone of the Kate Area will be discussed in detail.

Jan 1, 1980

By R. L. Marek

The number of Persons fatally injured in the petroleum industry in California in 1930 was 50, a decrease of 20.6 per cent from 1929, when 63 men accidentally lost their lives. The decrease in the number of fatalities for 1930 has caused the first downward trend in the fatality curve of the California petroleum industry since 1927 and is coincident with a period of little active development in new fields, the shutting in of many wells, and reduced activity in the older fields of the State. That a direct relationship exists between the number of accidental deaths and the rapidity of new field development is particularly emphasized by the fact that in 1929, a year of intensive field development in California, 48 men were killed in the drilling and producing division, whereas in 1930, a year of less development work, only 25 men were killed in this division. The figures for the average number of drilling and producing wells in 1930 decreased appreciably from comparable figures for 1929 and a greater percentage of producing wells were shut-in in 1930 than in 1929.

Jan 1, 1931

By A R. Penney

Since mining-induced seismicity first became apparent at the Beaconsfield Gold Mine in 2002, there has been an ongoing program of geotechnical investigations to understand the phenomenon and allow for the development of strategies to manage the risks it posed to personnel, the business and the community at large. Studies resulting from a seismically induced rockfall on Anzac Day 2006 have been extensive, and have advanced the understanding and management of seismicity at the mine. Enhancement of the mineÆs seismic array, implementation of extensive monitoring of ground behaviour, improved ground support and reinforcement design, and ongoing numerical modelling provide a technical framework for the management of seismicity. In addition, extensive involvement of the workforce in risk assessment and the development of standard work procedures (SWPs), has contributed to a æbest practiceÆ approach to manage seismic hazards at the mine.

Jan 1, 2008

By V. T. Dow

This report describes construction details and methods used in driving the 5490 tunnel at the Kennecott Copper Corp, property, Bingham, Utah. The tunnel will provide railroad access to the world-famous open-pit copper mine at the projected 5490 level. This publication is one of a series prepared by the Bureau of Mines to depict mining operations and techniques in various mining districts in the United States. Utah Construction and Mining Go. (formerly Utah Construction Co.), contractor on the tunnel project, began work during September 1956 and completed the project in February 1959. The tunnel is 18 feet wide, 24 feet high, and about 18,000 feet long, It will accommodate a railroad locomotive on standard- gage track. With the exception of the last 1,700 feet, the tunnel is supported by steel sets embedded in concrete lining. The 1,700-fact segment of the tunnel is supported by timber sets that will eventually be removed as the pit is deepened.

Jan 1, 1962

By Herty, C. H.

Three distinct processes take place during the conversion of iron ore to steel. First: the raw ore is reduced to metallic iron in the blast furnace and during this reduction certain constituents are dissolved in the iron, either through the solution of a solid into a liquid phase, as in the case of carbon, or by reduction of an oxide existing in the slag to the metallic element of that oxide, with subsequent solution of the metallic element in the iron. Thus by the process of solution and reduction, a pig iron results which contains about 4 per cent carbon, 1 per cent silicon, 1 to 2 per cent manganese, 0.1 to 0.4 per cent phosphorus, and 0.03 to 0.10 per cent sulfur. To obtain a sufficient yield of iron from the ore it is necessary that the reducing process be carried as far as possible, with the result that the impurities mentioned accompany the reduced iron. Second: to convert this iron into steel it is necessary to oxidize a part of the iron in eliminating the impurities to the extent desired for the particular product being made. In eliminating these impurities by oxidation a certain amount of iron oxide (FeO) dissolves in the steel. This dissolved FeO reacts with the metalloids, except sulfur, and to eliminate them to the desired extent it is necessary to leave a considerable amount of FeO in the metal. The reaction of iron oxide with silicon, manganese, and phosphorus results in the formation of the oxides of these elements. The oxides enter the slag and the extent of elimination of the elements depends on certain equilibria between the slag and the metal. The reaction of FeO with carbon results in the formation of the gases CO and CO, which, after saturating the metal, pass into the furnace gases. Third: after the iron has been purified to the desired extent as far as the elements listed are concerned, it is necessary to deoxidize the bath to remove the FeO, which is the vital factor in gas formation as the steel solidifies.

Jan 1, 1957

By R. P. Sloan, A. S. Whitford

In November 1999, CCI's Empire Iron Mining Partnership and MinnovEX Technologies Inc. developed an expert system for advanced control of their Empire IV Grinding Section. Empire IV is comprised of three autogenous Primary Mills and six autogenous Pebble Mills, with a single Pebble Crusher and high pressure Roll Press. The challenges of controlling and optimizing three distinct grinding lines that are inter-woven by a pebble crushing circuit were met with innovative and unique solutions. This paper will detail the approach employed at Empire and will focus on the aspects that make this application unique.

Jan 1, 2001

By Steve Kral

The mining industry has had three difficult years. Commodity prices have remained low and investor confidence in the industry has been shaken. And even though the Asian economy appears to be improving, it will be some time before this improvement will translate into better commodity price conditions for mining. In addition, increased environmental and social restrictions that have been placed on the industry in developed and developing countries have made mining a more difficult proposition. And, if that is not enough, the global mining industry has found itself in fierce competition with Internet businesses for investor capital. Despite that gloomy picture, more than 10,500 mining industry professionals from about 70 countries gathered in Toronto, Ontario March 5-10, 2000 for the Mining Millennium 2000 conference. This meeting was a joint effort between the Canadian Institute of Mining, Metallurgy and Petroleum(CIM) and the Prospectors and Developers Association of Canada (PDAC).The joint meeting also featured two trade exhibitions and more than 150speakers. PDAC’s trade show attracted about 400 exhibitors and an additional 200 in the concurrent Investors’ Exchange. CIM’s exhibition attracted about 600 equipment and service companies.

Jan 1, 2000

By C. O. Aksoy

There is a long history of coal production in Turkey with electric energy generated from power plants since the 1950s. However, the cost of power generation is high. Therefore, it has become necessary to find a means of decreasing production costs to become more competitive in a global market. This paper attempts to economically minimize the overall operating costs of a dragline-shovel-truck system applied at an open pit mine that has fed the Yatagan power plant since 1979, lowering the lignite production cost, and indirectly, the overall electricity generation unit cost. Systems currently in place, as a result of former optimization studies, are time-consuming and expensive to re-implement to comply with today’s very different geometric and economic conditions affecting mining operations. In such cases, rather than re-optimization, it is more viable to identify the parameters that affect the minimum unit cost, via a cost minimization study, allowing present mine equipment to be utilized more efficiently. Unit cost minimization analyses are subject to the capacity of the pool of mining equipment available, combined with the mining block geometry from pre-stripping onwards. In this overall unit cost minimization study, P&H shovels and CAT 777 trucks with capacities of 15 yd3 and 77 tons, respectively, were used in truck-shovel pre-stripping operations. A 65 yd3 Marion 8050 dragline was used to expose the overburden immediately over the coal seam. Pre-stripping bench heights varied from 8 m to 20 m and dragline bench heights from 20 m and 25 m were evaluated to minimize the unit cost of field operations. Total overburden extended to a depth of 60 m (35 m to 40 m for pre-stripping). Minimization analyses performed on the pre-stripping truck-shovel operation, prior to dragline operations, determined that the shovel bench height should be 15 m requiring a dragline bench height of 25 m.

Jan 1, 2005

By M. R. Peterson

The U.S. Bureau of Mines investigated column flotation for recovery of a high-grade fluorite (CaF2) concentrate and byproduct concentrates from the Fish Creek fluorite deposit in Eureka County, NY. The recovery scheme consisted of (1) grinding the ore to minus 48 mesh, (2) fluorite rougher and cleaner flotation, (3) desliming the rougher fluorite flotation tailings at 20 Jjm, (4) mica flotation, and (5) silicate rougher flotation. Acid-grade fluorspar, mica, free silica (Si02) sand, and low-grade beryl (Be3Al2S~018) concentrate were produced in a 100 lb/h continuous column flotation unit (CCFU). The highest results achieved were %.6-pct CaF2 recovery in a fIrst cleaner concentrate containing 99.7 pct CaF2. Beryl recovery was as high as 92 pct at a grade of 5.3 pct BeO. The silica sand, which assayed 98 pct Si02, was recovered as the rougher beryl flotation tailings. Collector reagent consumption was reduced 45 pct for fluorite and 58 pet for silicate flotation in comparison with bench-scale conventional flotation. All products were signillcantly improved in both grade and recovery over conventional flotation results, and the recovery scheme was simplifIed by removal of several stages of flotation in the fluorite and silicate flotation steps.

Jan 1, 1990

By Michael R. King

The application and use of steel fibre reinforced concrete in precast tunnel lining design is a growing trend due to its advantages in performance over plain concrete, and ease of manufacture compared to traditionally reinforced concrete. However, the design process and performance characteristics of the material are poorly served by current codes and standards. This paper provides some basic design guidance for segmental linings, and compares the material properties for the different material options. A typical example is considered to compare the possible results of lining arrangement and thicknesses for a plain, reinforced, and fibre reinforced design solution.

Jan 1, 2005

By S M Richardson, A W McNeill, J B. Gemmell

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Hellyer, Fossey, Que River and Mount Charter volcanic-hosted massive sulfide (VHMS) deposits occur within the Que-Hellyer volcanics of the Mount Read volcanics, Tasmania. These deposits occur along a 6 km strike length and are hosted by the same stratigraphic unit. We use a combination of whole-rock geochemistry, short wavelength infrared (SWIR) spectrometry, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses and compiled historic whole-rock geochemical data to develop district-scale vectors towards VHMS mineralisation.Strongly sericite and K-feldspar altered rocks concentrate along a linear trend from Hellyer, through Que River, to Mount Charter. Ishikawa alteration index values and whole-rock major and trace element concentrations provide exploration vectors towards mineralisation on a regional scale as significant enrichment and depletion trends. On a deposit scale, composition variations in white mica (sericite alteration), chlorite and K-feldspar are observed and reflected in whole-rock geochemical variations. Regional SWIR data from drill core support the prevalence of phengitic mica and high-Mg chlorite within footwall alteration halos and highlight the main upflow zones of hydrothermal fluids in the VHMS district. The combined use of regional whole-rock geochemistry, SWIR and mineral chemistry is an effective way to highlight prospective areas for VHMS mineralisation in a mature exploration province.CITATION:Wu, S, Gemmell, J B, McNeill, A W and Richardson, S M, 2015. Exploration implications from variations in whole-rock and mineral chemistry around the volcanic-hosted massive sulfide deposits of the Que-Hellyer volcanics, Tasmania, Australia , in Proceedings PACRIM 2015 Congress, pp 85–90 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Erika Moonin, Jim Nickerson, Marcus Jensen

"This paper will explain how the Contractor and Owner avoided a contractual dispute involving characterization, impacts, and final remedy for challenging ground conditions encountered during drill and blast excavation of the starter tunnel required for launch of the tunnel boring machine (TBM). During excavation more than 600 feet underground, the Contractor encountered a large complex fault zone subject to more than 14 bar of water pressure. Successive ground inflows from the fault complex over a six-month period presented significant technical and partnership challenges for the team and ultimately delayed the project by nearly one year. This paper will discuss how the Contractor, Owner, and their respective consultants worked together to address these challenges, make decisions, and ultimately move the project to successful completion. PROJECT BACKGROUND AND NEED Seven states of the western United States of America rely heavily on the Colorado River and its tributaries for their water supply. The primary source of water for the Colorado River is winter snow that falls in the mountains ringing the Colorado River basin, including the Rocky Mountains, the Wind River Mountains, and the Uinta Mountains. Flows in the Colorado River vary significantly from year to year, depending on the amount of snow and rain deposited in the basin. During the 1980s and 1990s, snowfall was relatively abundant and Colorado River flows were high on average. Beginning in the year 2000 and continuing to the present day, snowfall has been well below documented historical averages and Colorado River flows have diminished. In fact, a trend toward diminishing flows is evident during the period of the historical record. This variability in Colorado River flows and the trend to lower flows is represented in the following Figure 1."

Jan 1, 2016

By R L. Langak, R A. Heins

The use of differences in specific gravity between minerals to separate them has long been utilized in the extractive industries. The environmental and cost benefits of the commercialized forms of these processes are well understood and widely used. Gravity concentration is used inter alia in the primary beneficiation of gold, diamonds, coal, tin, ferrous metal ores and andalusite. The potential for economic loss due to poor performance of these gravity processes is significant, but diverse in manifestation and regular process monitoring can prevent or at least reduce these losses. The measurement of performance of gravity processes has always presented a challenge, due primarily to the masses of material involved and the physical nature of the processes, generally typified by long reporting time, and hazardous materials (such as Tetrabromoethane) for float and sink type tests. The development of density tracers has improved this situation, however recovery of these tracers from the process streams created the next set of challenges, requiring significant manpower to physically remove tracers from product dewatering screens. Additions to these tracers (magnetic or x-ray fluorescent) eased the recovery mechanism issues but made them much more expensive to produce, hence operators became concerned about losses during process testing. In addition, magnetic recovery of smaller size tracers by a magnet suspended above a loaded screen panel is still problematic. The development of new low cost magnetic tracers has improved statistical significance of tracer tests, as the tracers themselves can be bought and used in much larger quantities, whilst still remaining economically viable. Coupled with the development of effective magnetic recovery technology, such as the Gekko MagScreen, for even fine sized tracers, on-line, continuous tracer testing is now becoming a reality. Whilst the development of high technology radio frequency detection tracer systems continues, enabling the real time measurement of the process and interpretation of results, miniaturization and recovery of these tracers, which is critical given their costs at present, remains an issue. Keywords: Gravity, process measurement, tracers, magnetic recovery

Jan 1, 2006

By A. R. Barnes, A. F. Newall

Keywords: Pyrometallurgy, furnace, smelting, spinel, PGM, phase diagrams As Merensky reef ores are replaced by UG2 ores, chromium levels in PGM smelting furnace feeds have steadily increased. Increased chromium levels lead to operating problems. Attempts to increase the chromium solubility in the slag by a variety of techniques create other difficulties. The authors have developed a technique for removal of the chromium spinel interface along with the matte for subsequent separation outside the smelting furnace by utilising differential solidification in the ladle. The process has been patented internationally with support from the Innovation Fund.

Jan 1, 2006

By Russell Barr

Operational excellence is generally known as a management system integrated across critical functions that is geared towards continually improving operational performance. Functional areas such as health, environment and safety, quality and human resources are the focus of many corporate-wide operational excellence programs. Operational excellence also focuses on improving areas such as customer orientation, employee empowerment as well as process, and systems optimization. It is widely viewed as critical to sustaining business performance improvement. Although it is difficult to find a universally accepted definition, or even common foundation in many respects, operational excellence remains a popular term in the business world. Many organizations have developed their own version of organization excellence, influenced by such individual factors, other similar institutions or even third-party service providers. A mining organization is no different from other organizations in that adopting and implementing effective operational excellence programs can dramatically improve business execution and performance across regional or global interests. This paper brings together various perspectives of operational excellence and reconciles them for a useful composite for the mining industry. While most agree that operational excellence should include normal functions in a manufacturing operation such as production, maintenance and engineering and processes such as quality, environmental and continuous improvement, many other factors for operational excellence seem to vary from perspective to perspective. Thus, programs that manufacturers engage in may seem the same, but may, in fact, be different in key areas. This may affect organizational performance in tangible ways. Management must buy into the company?s definition of operational excellence and be dedicated to achieving it. A review of many of the existing definitions of operational excellence, explicit or embedded as part of a program, seems to yield the following common factors: ? It should help organizations better execute their processes and services. ? It should be geared towards improving quality ? It requires that the various operations should be aligned with the overall enterprise strategy. ? It should be geared towards continuous improvement. A composite of operational excellence definitions suggest that it is: ? Geared towards helping the organization achieve sustained profitability; ? tied to strategic alignment and business objectives; ? tied to solid investment strategies; ? integrated as part of the culture, process, time plan and performance; ? a relevant performance measurement system; ? extended to include all aspects of the supply chain (including external suppliers); ? integrated with health, safety and environmental (HSE) aspects. And, while the pursuit of operational excellence intuitively suggests that businesses should improve, it is very difficult to achieve given the difficult challenges facing companies today. Mining businesses face numerous pressures to perform in a global marketplace such as demand, energy cost, variable cost and pricing fluctuations as well as infrastructure challenges to further confound the environment. Companies generally must look to the following:

Jan 1, 2009

By E. R. Maize

This report is t e second of s series on roof movement in coal mines. The first (R. I. 3355)4/ dealt with convergence of roof and floor and movement of the surface accompanying and following extraction in a mechanized mine in which retreat of rib lines was rapid. The studies reported herein were made in a mine in which all the coal is loaded by hand, and movement of the rib lines was much slower in consequence. In choosing a site for this work, it was decided that the mine selected should have natural conditions akin to those of the first study and entirely different methods of working. To this end a cooperative agreement was made with the Crucible Fuel Co. through W. J. Whitaker, secretary, for conducting the work in the company?s Crucible mine, operating in the Pittsburgh bed in Greene County, Pa, This paper gives an account of the methods used in the investigation, excerpts from the data obtained, and such generalizations as can be made.

Jan 1, 1939

By C. C. Miller, A. R. Belyea, C. H. Herty, E. B. Burkart

The removal of sulfur from steel has been studied by many investigators, but the quantitative relationships between the factors involved have not been determined. This is undoubtedly due to the number of variables encountered in practice, an attempt to study any one reaction or relation being affected by other reactions the relative importance of which cannot be estimated. The factors that affect the extent of removal of sulfur in the basic open-hearth process are generally considered to be: 1. Basicity of the slag: (a) Iron oxides in the slag; (b) carbon in the metal or carbide in the slag; (c) temperature. These factors affect the reactions: FeS + CaO = CaS + FeO FeS + CaO + C = CaS + CO + Fe. 2. Amount of sulfur in the gas. 3. Amount of manganese in the metal. The factors which affect the rate of removal of sulfur include, in addition to these: 4. Fluidity of the slag: (a) Normal changes in fluidity with temperature; (b) changes in fluidity because of the addition of special reagents such as fluorspar. 5. Agitation of the bath. Within the past two years, two papers have been presented dealing with the influence of sulfur in the gas on slag and metal. Nead' has shown that if a gas high in sulfur be used for heating, the metal and slag will absorb sulfur. Whitely2 concluded from his experiments that if a

Jan 1, 1925

By A. Dean, J. Roberts, I. Stone, J. R. Merefield

Paper presented at the conference: Risk assessment in the extractive industries, held in Exeter, UK, 23-24 March 1994, and first published London: IMM, 1994, preprint volume, 10pp., 11 refs. No completely reliable method for characterising and quantifying airborne dust risk exists. A new monitoring technology has been developed whereby dust collected from four-way directional and high volume samplers is analysed for mineral content and particle size for integrated dust mapping. A dust database was set up for the area surrounding the Ffos Las open cast coal site in South Wales. It included XRD directional traces from 17 gauges over 20 months, XRD traces from window ledges in the nearby communities, the major soil types in the area, dust data from haulage roads and public roads and reference-type mineral samples. The database can be accessed relationally to compare and analyse the data using mineral, direction, time, weather and geographical relationships. The data has been used to assess areas of low, intermediate and high levels of risk from dust fall-out

Apr 1, 1995