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The 8 ft by 91/2 ft drive which joined No. 7 Shaft with Browne Shaft on the 1,480 ft level was extended from both ends and met at a point approximately 12,000 ft from No. 7 (2,000 ft from Browne).The surveying required for this 2 1/2 mile haulage drive called for greater accuracy than was obtainable from South Mine standard methods. Procedures and devices from published information were tried and modified as required to suit local conditions. Several new methods were applied and improved as the drive advanced. The control of angular, linear and level measurements was perhaps considerably in excess of the requirements, but this was offset by abnormally large discrepancies resulting from shaft plumbing. The accuracy of the final breakthrough, although not to the standard desired, was sufficient to complete the connection without inconvenience and added cost.INTRODUCTIONThe acquisition of the Browne Shaft leases in January 1962 presented the management of Broken Hill South Limited with the problem of transporting ore from these leases to its mill. It was eventually decided that diesel locomotivehaulage through a 2t mile drive on the 1,480 ft level between the two mines was the best solution. The drive was advanced from both ends after Browne Shaft was deepened by 80 ft to reach the 1,480 ft level horizon. Each end advancedabout 15 ft/day with the miners working three 7 hr shifts. Blasting was restricted to the end of the shift.The survey work involved five shaft plumbings and 78 theodolite stations in a traverse, underground and surface,of more than 5 miles. Because of the exceptional length of the drive, an unusually high degree of reliability was required.The aim was for a maximum error at breakthrough of 1 ft 1 in 30,000, and to secure this, precise methods of linear measurement were necessary. Shaft plumbing in particular posed special difficulties.

Jan 1, 1965

Provide the U.S. mining industry with technology for designing environmentally sound, low-cost in situ leach mining operations to produce copper from small, deep, and/or low-grade copper oxide deposits. Approach Investigate the feasibility of a new mining method--in situ leach mining-as an alternative to conventional mining for copper. Study fundamental leaching technology that will facilitate future commercial operations. Develop guidelines and procedures that will enable mine operators to design and evaluate in situ leach mining operations for any specific copper oxide deposit.

Jan 1, 1989

By Charles B. Carpenter

[The Bureau of Mines selected Anahuac for a petroleum-engineering study because it is one of the notable fields of the Gulf Coast region. It is outstanding because the producing formation is very thick; ever modern technique of drilling' and development has been applied; complete records of all operations,, including detailed subsurface information have been kept; the field has ,been developed systematically; and every effort has been made to utilize the reservoir energy efficiently. Data and information pertaining to the development anal operation were collected, compiled, and studied by the writers as if the field were under single ownership. The chief aim of the study was to increase the accuracy of the existing methods of estimating reserves by applying all the data collected during the modern development of an oil field, These scientific aids include coring; electric logging; micropaleontology determinations of porosity, permeability of oil-bearing sands, and their connate water content; subsurface sampling of the reservoir oil; and depth-pressure measurements. Because the reservoir structure in the Anahuac field is extremely complex, special attention was given to methods of calculating the reservoir volume.]

Jan 1, 1941

By Deborah McCombe

-Canadian Regulators -Qualified Person -Professional Association -Resources & Reserves -Foreign Codes -Disclosure of Historical Resources -Issues in Application of Resources & Reserves -Industry Best Practices developed by CIM -Technical Report and Reserves and Resources -Summary

Jan 1, 2003

By Charles B. Carpenter

[The Bureau of Mines selected Anahuac for a petroleum-engineering study because it is one of the notable fields of the Gulf Coast region. It is outstanding because the producing for is very thick; every modern technique of drilling' and development has been applied; complete records of all operations,, including detailed subsurface information have been kept; the field has been developed systematically; and every effort has been made to utilize the reservoir energy efficiently Data and information pertaining to the development anal operation were collected, compiled, and studied by the writers as if the field were under single ownership. The chief aim-of the stud,, was to increase the accuracy of the existing methods of estimating reserves by applying all the data collected during the modern development of an oil-field, These scientific aids include coring; electric logging; micropaleontology determinations of porosity, permeability of oil-bearing sands, and their connate water content; subsurface sampling of the reservoir oil; and depth-pressure measurements. Because the reservoir structure in the Anahuac field is extremely complex, special attention was given to methods of calculating the reservoir volume.]

Jan 1, 1941

As noted by D.W. Fuerstenau in his Plenary Lecture at the Conference on Extractive Metallurgy of Gold and Base Metals, Kalgoorlie, Australia, "Com¬minution of solids is surely one of the oldest technologies that, even in this day and age of DNAs, chips and space exploration, continues to challenge our scientific acumen and engineering ingenuity." Thus, the fundamentals of comminution continue to receive a great deal of attention in the literature. This was particularly true in 1992 with the publication of the proceedings from the SME-sponsored symposium, Comminution Theory and Practice. Papers covering topics ranging from liberation to comminution fundamentals to novel size reduction techniques are included in this review. Liberation Liberation continued to be a prime area of research interest, not only in terms of liberation modeling, but also in understanding the basic mechanisms involved in mineral liberation. King (Comminution - Theory and Practice, pp. 3-15) described a method for determining the interphase area between mineral grains. He showed how the mea¬surement of interphase area before and after comminution could be used to determine the presence or absence of intergranular fracture. Lin, Miller and Cortes (Kona, Vol. 7) discussed the use of computed tomography (CT) as a nondestructive means of investigating three-dimensional particle composition. The use of this technique in constructing coal washability curves from CT data was presented.

Jan 1, 1993

By S. Maurhofer

The Uetliberg Tunnel in Switzerland is the longest tunnel in Zurich?s new Western Bypass Expressway, connecting the Birmensdorf bypass in the west with the existing Zurich-Chur national motorway in the east. Thus the tunnel links the Zurich-West motorway interchange with the Zurich-South interchange (shown in Figure 1). The Uetliberg Tunnel project comprises two parallel tubes, each about 4.4 km long. The two tunnel tubes are connected every 300 m by a transverse walkway and every 900 m by a transverse roadway (Figure 2). The SOS niches are spaced 150 m apart. Portal stations with machinery rooms are located at the west and east portals. The tunnel falls with a gradient of 1.6% from the west portal at Wannenboden to the east portal at Gänziloo. The Project costs are about CHF 1.12 billion. The carcass construction started in March 2001. The Opening of the Uetliberg Tunnel is planed in spring 2009.

A mobile vacuum sweeper to remove loose coal and coal dust from underground coal mine workings was designed, built, tested, and evaluated. The design was based on an extensive test program. Pick up and conveying rates vs. air volumes, velocities, and nozzle shapes were determined for coal rubble in a laboratory pneumatic handling system. A gas/solids separation system was developed and tested in the laboratory capable of separating the solids loading from the vacuum system air stream to the very high degree required to preclude degradation of the ambient (mine) air. Two designs were made, one for belt conveyor and one for general district cleanup. The belt cleanup machine was chosen for test and demonstrated in an underground coal mine performing cleanup work in belt haulageways and on ribs.

Jan 1, 1975

By P. S. Capper

"Generally speaking, the most intensive efforts at dust control in the mining industry have, in the past, been concerned with underground operations and where uranium ore or high silica material is processed. In the past several years, Stoop Rock has made Intensive efforts to reduce dust levels in it's Iron ore pelletizing complex. There have been no great engineering break-throughs with regard to dust control in such plants, and certainly no new engineering techniques have had to be applied at Steep Rock. This paper deals with how significant improvements in dust levels have been achieved through minor modification to dust collectors and ventilation units, improvements in operating practices, and education of supervisors and hourly personnel.PROCESS DESCRIPTIONSteep Rock Iron Mines is located 120 miles west of Thunder Bay near Atikokan. (fig. 1) Run-of-mine ore is pelletized along with some -1"" concentrate that has been processed in the concentrator (a summer operation only), which utilizes gravity separation to upgrade a mechanical mixture of ore and waste."

Jan 1, 1976

By Matthew E. Fowler

The Central Subway will extend the recently completed 8.2-km long Third Street Light Rail line another 2.7 km north through the Union Square shopping district to Chinatown with a concourse-to-concourse connection to the Powell Street BART Station. One mined and two cut-and-cover subway stations are planned. Particular challenges include: tunneling under existing tunnels; variable ground conditions ranging from saturated alluvium to fractured bedrock; a congested urban setting and large-span caverns. This paper gives an overview of the project as it stands midway through the preliminary engineering stage along with a discussion of the rationale and design approaches that are being used to address the construction challenges of restoring light rail service in the most densely developed areas of San Francisco.

Jan 1, 2008

By Cristiane Sales Gonçalves

O processo de injeção sob pressão de ligas de alumínio é empregado para a produção de peças diversas, destinadas principalmente à indústria automobilística, com a possibilidade de produzir peças complexas, contendo seções delgadas, e a alta velocidade de produção. O reduzido tempo de ciclo e as elevadas temperaturas envolvidas promovem danos por fadiga térmica na superfície de trabalho das matrizes, que crescem com o aumento da produção até atingirem condições que inviabilizam o uso da matriz. O presente trabalho visou estudar o efeito da nitretação na superfície do material, relacionando-o aos aspectos microestruturais e tensões residuais inseridas durante nitretação. O aço AISI H13, foi tratado para dureza de 45 HRC e posteriormente nitretado sob plasma em diversas condições de temperatura, tempo e composição da atmosfera gasosa. Os resultados obtidos mostraram que as variações dos parâmetros de nitretação afetam os perfis de dureza e de tensões residuais presentes nas camadas nitretadas, bem como os microconstituintes das mesmas. O material nitretado, após ser submetido a temperaturas da ordem de 600°C, apresentou redução no nível de tensões residuais de compressão, ocorrendo processo de alívio de tensões. O mesmo efeito não foi tão fortemente verificado no perfil de dureza do material.

Aug 8, 2018

By J. Greg Sanchez

The New South Ferry Terminal in the New York City Transit system represents an important milestone for the city. This is the first station designed and built in the 21st century. The design of the fire safety system included relying on Computational Fluid Dynamics to analyze the dispersion of heat and smoke, and modelling of people egress to determine the egress requirements. The project also looked into how to protect the structure from the heat exposure in order to meet the fire rating requirements. This paper provides an overview of the fire safety design approach taken to design the new South Ferry Terminal station in lower Manhattan and looks into fire modelling, structural fire protection, and station evacuation.

Jan 1, 2008

By Ingvar Janelid

DURING the last ten years, in the effort to save manpower and costs, methods of drilling and blasting in Sweden have changed and developed in a revolutionary manner. These developments have been accompanied by extensive alterations in methods of tunneling and in mining technique. Since the end of the 1940's there has been a 100 pct change-over in Sweden to the use of tungsten carbide tipped drill steel. Both investigations and practical results have shown clearly that a tungsten carbide chisel bit fastened directly on the drill steel is the most economical for Swedish conditions. This applies to drill steel up to the longest size it is practical to handle. In terms of drilling footage, durability of the drill steel and the tungsten carbide bit is generally the same. In this respect, therefore, a detachable bit offers no advantage over integral steel. Transportation of integral steel to the grinding plant, instead of detachable bits only, involves heavier work, but this is counteracted by placing grinding plants closer together or by grinding at the working place itself. The drilling rate with integral steel is higher, the trouble of changing bits is avoided, and the difficulties which always arise with joints are eliminated. At present steel dimensions are usually 7/8 in. with a shank 41/4 in. long, whereas the international standard shank was formerly 31/4 in. The longer shank renders possible a better guide control of the steel and consequently longer life for the rotation chuck and the water-flushing pipe. After extensive experiments and investigations, agreement has been reached in Sweden on certain series of standards, shown in Table I. Other steel dimensions are, of course, available for special purposes. The standard drill-steel set begins with a 34-mm diam and has a length interval of 2 2/3 ft. On the other hand, for ordinary drifting it has been proved more economical to use greater length intervals on the steel, so only one steel change is required for a 61/2-ft round. Moreover, owing to the relatively close hole spacing necessary in a drift round, it has been possible to reduce the diameters of the tungsten carbide bits. This results in faster and cheaper drilling. As shown by the table, the lengths of drill steels for normal drifting are 33/4 ft and 71/2 ft, with 29 and 28-mm diam bits. During the last few years operators have begun to use 3/4-in. drill steel in place of the 7/8-in. drill steel chiefly employed earlier. This is a valuable development in drilling technique, particularly in view of

Jan 1, 1955

By G. M. Zhao

The gasification of lump coke with CO2 was studied in a fixed-bed reactor. The effective diffusivity of the gas was evaluated from measurements of the reactivity of the lump coke, produced by BHP Steel in New South Wales, and from kinetic parameters that were determined from the reactivity of fine grains. The grain model of effective diffusion in porous media was adopted to express the gasification rate of the lump coke and was found to fit the experimental data well. The relationship between reactivity and textural characteristics of the coke was examined

Jun 18, 1905

By U König, N Norberg

To cope with varying raw material qualities and increasing prices for energy, a more frequent and accurate monitoring of the processing of iron ore became the focus in sinter plant operations. Traditionally, quality control in iron producing industries has relied on time-consuming wet chemistry or the analysis of the elemental composition. The mineralogy of a sinter that defines the properties and behaviour in the blast furnace is often not frequently monitored. One fast method to analyse the mineralogical composition of iron sinter, raw mixtures and iron ores is X-ray diffraction (XRD). Recently statistical methods such as similarity analysis or partial least square regression (PLSR) in combination with XRD raw data has become more and more popular in handling large amounts of data and correlating process-relevant parameters directly with an XRD measurement. PLSR can be used to correlate process parameters directly from the XRD pattern without investigating the mineral content. Hidden information that is present in the measurement but not determined with traditional methods can be used to improve the characterisation of the analysed materials.CITATION:König, U and Norberg, N, 2017. Iron sinter process control using X-ray diffraction – part : monitoring of low temperature degradation, in Proceedings Iron Ore 2017, pp 75–78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Robert F. Stewart

The oxidation of structural materials at high temperatures in gas-cooled systems can be greatly retarded by the addition of small amounts of hydrogen to the inert coolant. In experimental equipment for gasifying coal with heat transferred by helium, the oxidation of graphite and metals (molybdenum, tungsten, and certain stainless steels) by trace impurities in the coolant helium was virtually eliminated by adding 0.1 to 1.0 percent hydrogen. The reaction of hydrogen with praphite does not preclude its use to retard oxidation; at 2,400° F. only 0.2 pound of graphite per square foot per year is lost for each percent of hydrogen in the helium. The addition of hydrogen appeared to prevent the mass transfer of carbon often associated with oxidation of graphite, without causing noticeable embrittlement of stainless steels and molybdenum or other damaging effects. This method has been tested in precision gas-recycle systems and applied successfully for more than a year in a pilot-scale unit operating at 250 pounds per square inch gage and 2,400° F. It is now used routinely and can be applied to many gas-cooled systems operating at high temperatures.

Jan 1, 1962

By B. Wilshire, P. W. Davis

It has been shown that grain-boundary migration during high-temperature creep can reduce or even prevent the formation of intercrystalline voids, giving a considerable increase in ductility.' A similar observation has been made in a recent investigation of the creep properties of various grades of nickel and nickel alloys. The results can be illustrated by the observations made on: a) Pure vacuum-cast nickel (99.993 pct Ni) b) Impure vacuum-cast nickel (99.97 pct Ni) c) Pure nickel containing internal voids (produced by a process of intering). d) A substitutional solid solution alloy of pure nickel containing 1.16 pct Sn. All the materials were given a high-temperature anneal (>850°C) to produce a stable grain size of 7 to 10 grains per linear mm. The apparatus and techniques used to obtain the present results have been described elsewhere.' In this series, grain growth was observed only in the highest-purity, vacuum-cast metal. Thus we may consider that in the other materials grain-boundary migration was prevented by either preexisting voids or solute atoms. The effect of migration on the creep ductility of the above materials can be seen from Fig. 1, which

Jan 1, 1962

By James L. Ash

This report contains the results of a technical and economic evaluation of conceptual systems for the underground mining, rubblization; and in situ retorting of deep oil shale deposits. Study efforts were first directed towards evaluation of the applicable geology, associated minerals, rock mechanics, in situ retorting, access mining, ventilation, rubblization, safety, and environmental impact factors. Conceptual systems were synthesized and then evaluated against these factors from both a technical and limited economic viewpoint. The results of these evaluations were then analyzed 'and, based upon this analysis, the following two systems were selected for further study: System II: Room and Pillar-Vertical Drill and Blast System IV: Tunnel Boring-Horizontal Ring Drill and Blast Due to the large number of variables to be considered, a computer program was developed and utilized to provide data for the cost trade-off studies and economic analysis. Results of the early computer runs indicated the value of the tool available in the computer program and led to an extension in the contract to determine the sensitivity of the systems to several of the more apparent significant variables. These results in turn led to a refinement in the design assumptions and a better understanding of the technical and economic options available to an owner-operator of a Vertical Modified In Situ Shale Oil Extraction System. This report is submitted in fulfillment of the requirements of Contract Number S0241073 by Fenix & Scisson, Inc. to the Denver Research Center, United States Department of the Interior, Bureau of Mines. Work was completed as of November, 1976.

Jan 1, 1976

By James M. Spear

The U.S. Bureau of Mines conducted a mineral survey of the Domeland Addition (5207) and Woodpecker (5206) RARE II areas during the summer of 1979. These study areas were examined to determine the presence or absence of mineral resources and reserves and where possible, to estimate values. The study areas are 9 air mi northeast of Kernville, California, and encompass 47,400 acres of primarily granitic rocks of the Sierra Nevada batholith with some scattered exposures of older metasedimentary, volcanic, and metavolcanic rocks. These other rock units partially surround the exposed batholith in the Domeland Wilderness and consist mostly of late Paleozoic quartzites, mica schists, marbles, and meta-volcanics, Mesozoic quartz diorite and gabbro intrusives, and local Tertiary basalt and andesite flows.

Jan 1, 1981

By E. D. Gardner

This paper is the third of a series of three on placer mining in the western United States. The first paper4 discusses the history of placer mining in the Western States and the production of placer gold, geology of placer deposits, location of placer claims on public lands, sampling and estimation of gold placers, and classification of placer-mining methods, together with hand-shoveling and ground-sluicing. The second papers deals with hydraulicking, sluice boxes and riffles, recovery of gold and platinum from placer concentrates, treatment of amalgam, and marketing of placer gold. The discussion of sluice boxes and subsequent subjects in the second paper applies to all forms of placer mining. The present paper treats of dredging and other forms of mechanical handling of placer gravels, and drift mining.

Jan 1, 1934