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By Tian Li

Molecular crystal growth during gibbsite precipitation from caustic aluminate solutions under different flow regimes was investigated in three different laboratory precipitators. The gibbsite precipitation experiments were conducted at the same temperature, initial liquor composition and seed type. The Taylor-Couette precipitator and the stirred tank precipitator were operated, respectively, under the laminar and turbulent flow regimes, while the bottle roller precipitator was operated in a complex flow regime, where fluid flows are generated by the end-over-end rotation of the bottles. Comparison of the growth rate estimates from the different flow regimes showed good agreement, which suggests that the hydrodynamic regime has little or no effect on gibbsite crystal growth under the operating conditions employed in this work. The growth rate estimates from the current precipitation study showed a second order dependency on supersaturation and is consistent with a screw dislocation growth mechanism. The findings of the current work are in agreement with previous gibbsite crystal growth studies published in the literature.

Jan 1, 2003

By Antonio De Biase

In October 2006, a 7m Double Shield TBM, boring through very poor volcanic formations, was pushed back by fluid mud, which presence had not been detected during previous field investigations, due to the high covers characterizing the majority of the tunnel axis. The present work describes the investigations made to gain better knowledge of the conditions in front and all around the TBM, the special measures implemented, the exploratory and bypass tunnels excavated, the extraordinary occurrences came true during the execution of these tunnels, the drainage campaigns, the design of the chamber excavated to free the TBM, the dismounting and restarting of the TBM.

By R. J. Rotzinger

The Gibraltar Mine and Mill facility were commissioned in 1972 by Gibraltar Mines Ltd utilizing a flowsheet consisting of two stages of crushing followed by a rod mill / ball mill grinding circuit. During operations a number of opportunities were evaluated to expand the mill capacity; however, the economics of the day did not allow any of these projects to proceed. The mine continued to operate until late 1998 when it was shutdown and put on care and maintenance due to low commodity prices. Taseko Mines acquired Gibraltar in 1999 and in 2004, with the improvement in the metal markets, made the decision to restart operations. During the restart planning a number of opportunities for mill improvements and upgrades were identified and, after operations were successfully restarted, the decision was made to once again review expansion opportunities for Gibraltar. Taseko evaluated various expansion alternatives eventually deciding to install a SAG Mill, convert the existing rod mills to ball mills and distribute the SAG discharge to the resultant six 6 parallel ball mills. This paper discusses the design, implementation and commissioning of the SAG mill grinding circuit.

Jan 1, 2012

By R. J. Rotzinger, K. W. Major

The Gibraltar Mine and Mill facility were commissioned in 1972 by Gibraltar Mines Ltd utilizing a flowsheet consisting of two stages of crushing followed by a rod mill / ball mill grinding circuit. During operations a number of opportunities were evaluated to expand the mill capacity; however, the economics of the day did not allow any of these projects to proceed. The mine continued to operate until late 1998 when it was shutdown and put on care and maintenance due to low commodity prices. Taseko Mines acquired Gibraltar in 1999 and in 2004, with the improvement in the metal markets, made the decision to restart operations. During the restart planning a number of opportunities for mill improvements and upgrades were identified and, after operations were successfully restarted, the decision was made to once again review expansion opportunities for Gibraltar. Taseko evaluated various expansion alternatives eventually deciding to install a SAG Mill, convert the existing rod mills to ball mills and distribute the SAG discharge to the resultant six 6 parallel ball mills. This paper discusses the design, implementation and commissioning of the SAG mill grinding circuit.

Jan 1, 2012

Canada's newest low-grade porphyry copper mine, Gibralter Mines Ltd. (N.P.L.), has reached production. The subsidiary of Placer Development Ltd., located at Williams Lake in the Caraboo District of central British Columbia, began open pit mining in mid-June on reserves estimated at 358 million tons assaying 0.373r: Cu and 0.016C; MoS,. Each of four separate zones will be mined in a predetermined sequence, in one or more stages, and with a throughput of more than 36,000 tpd. The sequence and stages of mining the zones have been determined by computer calculation and economic analysis and are designed to maximize recovery and minimize cost. At the very least, the mine is off to a promising start. Development costs leveled off at $67 million. 9'; below the anticipated budget.

Jan 7, 1972

By Gilbert Soler

THIS year's Chairman of the Iron and Steel Division is a noted member of a small and select group of practical scientists now working in this country and in Canada to improve the production and properties and to reduce the cost of super-quality carbon and alloy steels; he is one of those all-important leavening agents-a man with his feet always on the ground but capable of putting his head into the clouds on occasion-that are so necessary in applying science sensibly to the practical problems of steel production. He is equally at home in a discussion of the free energy of deoxidizing reactions or the entropy of the formation of stable sulphides, and in a consideration of the relative advantages of the basic-electric and the open-hearth furnace for the production of rimming steels in the Detroit area. Gilbert Soler was born of American parents in Havana, Cuba, just forty years ago. He graduated as a ceramic engineer from Ohio State University in 1930 and received a Master of Science degree a year later. In 1940 he received the degree of metallurgical engineer from the same institution.

Jan 1, 1948

By William L. Jude

INTRODUCTION Although the mining method described in this chapter is locally designated "modified Mitchell," there are so many features which are characteristic of square sets that the designation "modified square set" would describe the method equally well. The method was developed as a result of local operating experience with various mining methods, observing operations in mines in the southwest where Mitchell stoping had been thoroughly developed, and an exhaustive study of min¬ing methods literature. Since 1941, modified Mitchell stopes have con¬tributed over 50% of the total stope production and were largely responsible for supporting production dur¬ing the war years and period of declining manpower and increasing costs. GEOLOGY The community of Gilman is situated on Battle Mountain at an elevation of 2743 m (9000 ft) in the Battle Mountain mining district, about 45 km (28 miles) by highway north of Leadville, CO. The sur¬rounding area, including the Mount of the Holy Cross and Eagle River Canyon, is noted for its beauty and recreational facilities, both summer and winter. Massive sulfide ore bodies of the limestone replace¬ment type occur as chimneys and mantas or as blankets in strata dipping 0.19 rad (11°) northeasterly. A chimney is shaped like an inverted cone with shale, quartzite, and porphyry caprocks forming its base. This relatively impervious capping apparently blocked rising ore constituents which formed the chimneys and mantas. At the apex or lower extremity of the chimneys, the ore follows small fractures and bedding planes in under¬lying quartzite. Dimensions of chimneys vary, ranging up to 61 m (200 ft) vertically and 76 m (250 ft) horizontally near capping. The manta or blanket ore bodies vary in vertical cross section from one hundred to several thousand feet. One such manta was developed from its outcrop to its chimney source approximately 610 m (2000 ft) downdip. Another manta of substantial cross section and length did not follow shale but extended updip with limestone capping from its source at a lower horizon. All chimneys, however, make up to the shale¬quartzite-porphyry capping. Chimney ore minerals are mainly pyrite and chalco¬pyrite with accessory copper and silver minerals, surrounded by, and in places overlain with, marmatite, pyrite, and galena. Manganosiderite extends into the ore. It may or may not be impregnated with sufficient marmatite and galena to be of commercial grade. Ore may be massive, coarsely crystalline, or sandy, some¬times rubbly. Generally speaking, chimney ore masses are incompetent and of variable grade. Caprock is heavy and caves readily. Manta ore minerals are mostly marmatite, pyrite, and galena associated with manganosiderite. Structural characteristics of the ore are similar to those found in chimneys and where the manta contact shale capping the ground is unusually heavy. However, the large manta with limestone capping mentioned previously consisted of a hard strong ore mass in fairly strong host rock. Commercial ore contacts are fairly regular in this manta but in others the ore waste contacts along the walls are irregular with shaly limestone pendants extend¬ing downward into the ore at capping. Dolomite sand is also quite frequently encountered along wall contacts and less frequently overhead. MINING METHODS Practically all stoping in the Gilman ore bodies has been carried on with timber and fill methods and the features which have been briefly described have dictated the choice. Although at the present time modified Mitchell and underhand square-set stopes account for the total production, considerable production has been obtained from alternate horizontal cut-and-fill stopes with Mitchell truss stopes in the pillars. This method was highly satisfactory in the hard manta ore body mentioned earlier and where ore excavations 11 m (35 ft) wide and 23 m (75 ft) long required no auxiliary timber support. It was a pillar recovery application of the method devised by M. W. Mitchell at the Calumet

Jan 1, 1982

By Harry D. Lewis

Gilsonite is a lustrous black material that can be easily crushed into a chocolate-colored powder. It is a solid but relatively soft, lightweight hydrocarbon that visually resembles the volcanic glass obsidian. It was once thought to be a type of coal, but because it is thermoplastic it melts rather than bums. Gilsonite is found in commercial quantities only in the Uinta Basin of eastern Utah and western Colorado, where it forms vertical, nearly parallel veins of varying depth, width, and length. Gilsonite from different veins has different properties, most notably variations in softening point and solubility. These differences result in its use in a variety of industrial applications. Gilsonite's earliest commercial uses were in varnishes, buggy paints, and beer vat linings. Eventually it came to be used in more than 160 products ranging from inks to explosives. It is exported from the United States to most industrialized countries throughout the world. Today, due to competition from synthetics and other hydrocarbon products, its use has narrowed to several specific industries. Although sold mostly as a commodity, current research is focused on applications for gilsonite as a value added product. Historical Overview The discovery of gold in California and the dawn of the mining era in Nevada, Colorado, and Utah around 1850 brought a wave of prospectors to the western United States. One of those pioneers, Samuel H. Gilson, is generally credited with a major role in the discovery of gilsonite. The material now known as gilsonite was discovered several times from the late 1860s through the mid-1880s. It was William P. Blake who, after receiving samples of the material, wrote a paper in 1885 describing "a new variety of asphaltum from the Uinta Mountains." He termed the material uintaite. Although Sam Gilson was not the first to discover the mineral, he was an-inventor who used gilsonite in products that he patented. It was his conviction that the substance was of great value, which caused some to refer to it as gilsonite. The term Gilsonite became the registered trademark of the American Gilsonite Co., and it continues to be in use today. When the first company was formed to mine this substance in 1886 it was named the Gilsonite Manufacturing Co. This firm acquired many gilsonite mining claims and marketed a varnish made from the material. It was the unusual properties of gilsonite varnish that attracted the attention of Adolphus Busch of the Anheuser-Busch Brewing Co. In 1889 Anheuser-Busch bought out Gilson's interests and formed the Gilson Asphaltum Co. Busch had been importing asphalt from Sicily for use in lining beer barrels and saw gilsonite as being more readily available and cheaper. Although gilsonite did not work well in this application, Busch did acquire a large number of mining claims in the Uinta Basin. In 1903 the parent firm of Gilson Asphaltum financed the building of an 85-km railroad from near Grand Junction, CO, to Dragon, UT, to haul gilsonite ore to market. Underground mining was initially centered near Dragon and then later at Bonanza, UT, as different veins were mined. The railway was abandoned in 1937 in favor of truck transportation. In 1938 Gilson Asphaltum changed its name to Barber Asphalt Co., the predecessor of Barber Oil Corp. In 1946 Barber Oil teamed with Standard Oil of California to form a partnership, American Gilsonite Co., which today has its operational headquarters at Bonanza, UT. Barber Oil investigated many new uses for gilsonite, including the making of petroleum derivatives such as gasoline. This work led to the construction of a 116-km pipeline to carry slurried gilsonite to a refinery in Colorado for the production of gasoline, fuel oil, and coke. Pipeline operations began in 1957 but stopped when the economics of competing with petroleum became unfavorable, and the refinery was sold in 1973. In 1981 Standard Oil (later Chevron) became the sole owner of American Gilsonite and remained so until 1991, when it sold its interest to Stratford Enterprises Co. of Tulsa, OK. The companies have since been merged and now operate under the name American Gilsonite Co. with headquarters in Salt Lake City, UT. American Gilsonite continues to be the world's largest miner and supplier of the mineral. The American Asphalt Association was formed in 1902 by former stockholders in Gilson Asphaltum. This company mined various gilsonite claims until it was dissolved in 1953 and its properties were sold to American Gilsonite and Gordon S. Ziegler and Associates. The Utah Gilsonite Co. was established in 1920 and mined several claims until 1952, when its holdings were sold to Gordon Ziegler. Several other gilsonite mining ventures have been pursued in Utah, although they were significantly smaller in scale than those described above. There are currently three companies which mine gilsonite resin in Utah. They are American Gilsonite Co., Ziegler Chemical & Mineral Corp., and Lexco.

Jan 1, 1994

By G. R. Burman

Gilsonite is a brittle, natural solid bituminous resin, classified as an asphaltite. It is found in near-vertical veins in the Uintah Basin of Eastern Utah. Discovered well over 100 years ago by Samuel Gilson, this unique material has, since its finding, enjoyed a variety of commercial and industrial applications. Early uses for the product included black automotive paint and beer vat linings. Among its many important uses today are additives for oil well drilling fluids and cements, additives for sand castings for the foundry industry, reinforcing agent for asphalt pavements, and dispersing agent for black inks. Gilsonite is mined and processed in Bonanza, Utah, by two companies, American Gilsonite Company (AGC), an operating division of Chevron Resources, and Ziegler Chemical, a privately held company headquartered in New York.

Jan 1, 1990

During the period 1981 - 1991, Esso Australia and their Joint Venture partners have discovered about 180 MB of liquids (crude and condensate), 60 MB natural gas liquids and 800 - 1000 GCF of gas. A total of 48 wildcat wells were drilled including 12 new pool discoveries drilled from platform facilities. Significant discoveries include the West Tuna, Kipper, Blackback and Terakihi fields. These four discoveries, contribute to 75 per cent of the total reserves discovered in the last decade and were all high-risk plays. The Kipper discovery, in the pre-Latrobe Golden Beach Group top sealed by volcanics, and the Blackback-Terakihi discoveries, located on the present day continental slope in water depths ranging from 300-700 metres are both the result of successful drilling outside the traditional exploration bounds for the basin. During the last decade, Esso and its partners have spent about A$400M on wildcat exploration activity. The exploration success rate, excluding platform based drilling, has been 50 per cent for wildcat wells. On a technical front, the last decade has heralded substantial improvements in seismic data quality. Peak frequency content in seismic data at the Latrobe Group target levels is now double that of the early 1980s. Significant advances have also been made in our understanding of sequence stratigraphy, geochemistry and geohistory of the basin.

Jan 1, 1992

It has long been recognised that Australia can benefit substantially in an economic sense from its rich resource base. The significant resources of the Gippsland Basin are a good example of the wealth of this nation. As cited in popular debate, Australia must value-add to its natural resources to ensure its long term economic prosperity. The significant oil, gas and coal resources of the Gippsland Basin have provided the Strategic Research Foundation with the basis for two major research and development initiatives ensuring the long term economic development of the Basin and Australia. The gas and coal reserves of the Basin together with the area's extensive history in electricity generation provide the rationale for establishing Ceramic Fuel Cells Ltd. A consortium comprising Australia's leading industrialist - BHP, State energy authorities and the Nation's major research and development organisations, has formed Ceramic Fuel Cells to undertake and manage research, development and commercialisation of solid oxide (ceramic) fuel cells which convert fossil fuels directly to electricity with greater efficiency and less pollution than existing technologies. The oil and gas resources of the Basin together with the valuable experience of the operators in recovering these resources, have provided the impetus to investigate the feasibility of a Marine Engineering Research Centre. The commercially oriented research, education and training objectives of the Centre are well supported by the leading industrialists in related industries.

Jan 1, 1992

I The South Platform of the Gippsland Basin is an extensive area of shallow basement covered by a relatively-thin Late Mesozoic-Cainozoic section. Although the sporadic exploration to-date has not resulted in any hydrocarbon discoveries, the area is under-explored and its taste potential has not yet been fully evaluated. The best potential appears to be in areas underlain by the Golden Beach Megasequence where structures are mainly related to basement fault blocks.

Jan 1, 1992

By Charles H. Addison, Robert W. Shields, James W. Sweeney

GIPSY: Is user oriented. Is flexible in applications. Is an ITERATIVE question answering system. Has an adaptable retrieval mechanism. Has both a batch and a teleprocessing version. Allows the user to "browse" through his information. Has ability to answer "ad hoc" queries. Is a currently working and proven system.

Jan 1, 1969

By Jim Baumann

Deposited millions of years ago in irregular paleokarstic channels, Jamaica’s extensive bauxite deposits provide good quality ore for alumina production and subsequent aluminum smelting. Bauxite mining operations are critical to the Jamaican economy. It accounts for a large percentage of Jamaica’s export earnings. Bauxite production in Jamaica accounts for about 10% of the world’s output each year. Bauxite deposits in Jamaica lie close to the surface. They can be extracted using standard surface mining techniques. The deposits occur in scattered pockets across the country’s rugged landscape. So it was necessary for two of the country’s major mining and refining operations to implement cost effective methods for the acquisition and management of bauxite reserves and surface ownership distribution rights.

Jan 1, 2002

By Samir Kumar Das

Presently Geographic Information System (GIs) is gaining wider acceptance id appreciation in various resource management surveys, generation of various thematic maps, various scientific investigations, environment assessment, disaster management, etc in India but they are general in nature. A huge number of Global Positioning System (GPS) based "Total Station" are playing good roles in India for accurate and quick surveying . The GPS based real time Mine Management and Truck Dispatching System for optimization of productivity is being installed in the Panchpatmali opencast bauxite mines of India. This paper dealt in depth on GIs and GPS and their present roles in the Indian mining scenario.

Jan 1, 2002

By Anthony D. Hammond

The use of geographic information systems (GIS) as a tool to analyze and display data is gathering momentum in the mining industry. Of particular interest is the capability of GIS to link spatial features and tabular data. The application of GIS in underground mining discussed here concentrates on four technical areas. They are land ownership and mineral claims, exploration management, production and mine safety.

Jan 1, 2002

By D Craw, P Whigham, C Rufaut

Geographic Information Systems (GIS) are computerised management systems for spatial data, offering improved data management, extensive data manipulation techniques and greater understanding of data. At the Wangaloa Coal Mine, South-East Otago, ArcGIS is being used to manage, integrate, analyse and visualise the diverse range of datasets being generated from an interdisciplinary research team. GIS will assist with identifying spatial and temporal patterns associated with the current site rehabilitation strategy. This paper will present an overview of how GIS can be a useful tool for understanding ecological recovery during mine site rehabilitation.   The Wangaloa opencast coal mine, owned by Solid Energy NZ Ltd, was closed in 1989 after more than 40 years of operation. Rehabilitation efforts involving more than 60 000 native plants began in October 2001. At Wangaloa sample points were randomly selected at 100 m intervals and recorded using a differential GPS. Plant, soil and invertebrate data have been collected at each sample point. Plots of 8 - 9 plants have been established within approximately 5 m of each sample point. Since September 2003 seasonal monitoring of plant growth and survival has been carried out. Chemical and physical datasets have been generated from soil collected in June and December 2003 for each sample point. A more restricted dataset is being generated for soil collected on a seasonal basis from March 2004. Plant and soil characteristics from these datasets have been attached to each sample point and GIS layers have been created. Relationships between data layers can be explored based on their spatial patterns. Examples presented from Wangaloa include distribution of planting success and temporal variation; temporal change in pH; interpolated pH map; digital elevation model; relationships between planting success and growth with pH and organic matter. GIS is proving to be a valuable tool on the integrated project at Wangaloa.

Jan 1, 2004

By J B. Taylor

Geographic Information Systems (GIS) are being increasingly used by the mineral exploration industry in the search for new ore deposits. A mineral exploration GIS links geological and geophysical data by virtue of their geographic location in a digital map setting. Geological and geophysical data are categorised into a number of themes or layers within a mineral exploration GIS. These layers may include polygonal information such as rock type and tenements, line information such as faults and fold axes, point information such as mines and mineral occurences, and images such as gridded geochemistry and aeromagnetics. A mineral exploration GIS is a powerful tool to help the explorationist comprehend the spatial associations and interrelationships of his/her data. These spatial associations can be integrated with a mineral genesis model, to create a mineral prospectivity map to more effectively target exploration. Arguably a competent geologist who has a good understanding of the genesis of the local ore deposit types and knows their local geology backwards could intuitively derive a mineral prospectivity map. However, in an era of rapid data accumulation from many different disciplines, the ability to assimilate and understand is a huge task for any individual. A mineral exploration GIS enables the explorationist to spend more time analysing data and testing ideas, rather than finding and manipulating data into compatible formats.

Jan 1, 1994

By Alexander Kattner

Surface fractures in urbanized areas show the risk potential of near-surface mining. This kind of mining subsidence damage occurs mainly in areas where hard coal was mined near the surface with very little overlying rock strata. In North Rhine-Westphalia (NRW), the mining authorities assess areas that are at risk for caveins by means of envelopes constructed according to Hollmann and Nürenberg (1972). Drafting abandoned underground structures depends on the assessment of historical documents such as mine plans, mine titles, and operation plans of prior mines in this area. A research and development project establishing a comprehensive Geo Information System (GIS) for hazard prevention was undertaken in cooperation with the mining authorities of NRW. It aims to display the areas endangered by abandoned, shallow underground mines for the purpose of hazard prevention. A tool was programmed using ArcGIS as a result of this project. It is used to digitize underground workings from preserved mine plans, calculate outcrop lines of coal seams and display hazardous areas. In the future, a database of shallow mine workings will be established. The tool will be used for a systematical mapping of shallow workings and assessment of endangered areas.

Jan 1, 2011

By G. Howell, J. Wates, A. Coetzee, C. J. MacRobert

The Global Industry Standard on Tailings Management (GISTM) requires mining companies to make four key appointments as part of their tailings management structure. These four positions are an Accountable Executive with policymaking responsibilities, a Responsible Tailings Facility Engineer with operational responsibility, an Engineer of Record to ensure facilities are designed, operated, and closed safely, and an Independent Tailings Review Board to assess safety drivers regularly. Little guidance on the traits of these individuals is available in a South African context. Consequently, the tailings community of practice was surveyed to develop a table of ideal competencies and establish the flexibility in meeting these traits.

Jun 2, 2022