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By C. E. Rodgers

WHEN I was asked to prepare, for presentation at the 1938 Annual Meeting of the Institute, some data concerning low-discharge grinding at the Sylvanite mill, it seemed entirely reasonable to expect to have at my disposal the results of at least four full months' operation after the last unit, as then proposed, was installed. Delays in delivery of equipment, nevertheless, shortened the interval, as will be shown herein. In submitting the data contained in this discussion, I wish distinctly to state that the intention is not to claim that final conclusions can be reached at this time concerning our operation. Test periods, in certain instances at least, have been too short for this purpose, although some, where so stated, have been extended through March and April. It is hoped, however, that an advantageous trend in practice can be shown and that the experience related may be of interest to others who are now operating, or who are considering the operation of, low-discharge grinding mills. In the plant under review, four mills are in use: one primary and three secondary. Present mill capacity (grinding, as shown by screen test, about 99 per cent through-200-mesh and approximately 88 to 89 per cent minus-325-mesh with infrasizer giving about 90 per cent of the latter) averages about 525 tons per day. A brief description of each unit will be given and comments will also be made relating to operation. This will be followed by certain test data from which, in conclusion, operating results are summarized.

Jan 1, 1938

By R. A. Cattell

Since the return of the Petroleum and Natural Gas Division of the Bureau of Mines to normal peacetime functions following World War II, a coordinated program of oil and gas development and production research has been in prog- ress, and the importance of the problems has been evaluated so that the Bureau can render greater service to the oil and gas industry. Among the problems associated with development and production research, those concerned with efficient utilization of the Nation's reserves of hydro- carbons contained in gas-condensate type reservoirs continue to receive major emphasis. For a number of years an important part of the Bureau's work has been the study of two pressing problems associated with production from such reservoirs; first; an investigation of fluid properties, and the second, finding a means of controlling corrosion. Studies of the characteristics of gas-condensate fluids have resulted in the publication of a number of reports, which cover a broad field. In general they deal with subjects such as the properties of a fluid from a well; development of research equipment, means of combatting corrosion, and the many aspects of gas-condensate engineering. To provide experimental data on relative liquid and gas volumes and critical pressures and temperatures, a windowed cell was constructed that permits ob- servation of the fluid phase while making the tests. Experimentation in the field on the use of inhibitors to control corro- sion of equipment in gas-condensate wells has disclosed that solutions of chromate are effective retardants of corrosion. Engineering field studies of the Carthage and New Hope gas-condensate fields are in progress, and reports on the Sheridan and Lake Creek fields have been completed. Following a plan of making studies of important newly discovered oil fields, the Bureau is investigating the physical properties of reservoir oil

Dec 1, 1948

By R. E. Heithecker

In Kansas, almost every oil well drilled into a limestone formation is treated with hydrochloric (muriatic) acid upon completion. This is done to increase the potential capacity of the well and thereby increase its "daily allowable" production (see p. 9 ), to shorten the time required to produce the recoverable oil, and to increase the quantity of oil recovered ultimately from the reservoir. The porosity and. permeability of limestone formations seldom are uniform throughout the proved area, consequently the production capacities of completed wells vary considerably. Acid treatment of wells tends to increase production capacity and to equalize potential capacity. If offset wells already have been treated with acid, new wells usually are treated to protect the property on which they are drilled against drainage. Even though competitive conditions do not exist in a field, it

Jan 1, 1939

By D. C. Seidel

This report describes generic procedures and equipment arrangements for conducting laboratory-scale hydrometallurgical and related waste-management experiments. It provides a starting point for personnel who have received or are receiving professional training, but do not have specific experience in laboratory procedures. With guidance, it also has application as a resource for technician training. The publication contains chapters on laboratory safety, feed-sample preparation, leaching, solids-liquid separation, and recovery from solution.

Jan 1, 1995

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4/ issued by the Bureau of Mines, the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1957

By D. W. Dareing

Multiple branch wellbores and horizontal holes, when applied to deep lying ore bodies, have the potential of significantly reducing well costs by reducing total footage drilled per acre of well pattern. In addition, horizontal holes may increase sweep efficiency. Well completion is a major problem. They must be cased to contain leaching solutions within the underground portion of the production loop. Several drilling and completion concepts are given and evaluated in the report. Our evaluation shows that there is economic incentive to further develop these concepts for field application to ore bodies 1,500 feet. Multiple branch concepts are the most attractive. They can reduce well costs by as much as 30° when applied to 2,000 feet ore body depths (44%, at 5,000 feet) and can accommodate a lamer pump than conventional vertical wells. We recommend this concept be developed further to accommodate either dual or triple branches.

Jan 1, 1980

By George H. Holmes

The water situation in Nevada mineral and related industries is described in this report. It contains information on the sources and adequacy of supply to current operators, requirements and uses, quality and costs, geography, hydrography, precipitation and evaporation characteristics, and Nevada water laws. Also, information is given on the water requirements of one public utility powerplant, and the source and consumption of water in four major cities. Water distribution at 24 operations is shown on schematic waterflow diagrams. The mineral industries of Nevada in 1962 used 8.6 billion gallons of nee' water and reused 3.8 billion gallons for a total usage of 12.4 billion gal¬lons. The copper industry was the major water user. The 1962 value of all mineral production in Nevada was $85.5 million. The large amount of water required to maintain this high production is obtained principally from ground-water sources in alluvial valleys and the permeable rock formations of some mountain ranges. Some water is also obtained from perennial streams and springs. Sources of water utilized by existing industry ore near most mineral industry operations; however, seven companies are forced to pipe water distances ranging from 2 to 8 miles. Although water supplies of presently operating companies are adequate at most operations, several companies resort to large-scale reuse of water as a matter of conservation and economics. Acquisition of water by new operators is possible but takes considerable negotiation. Water rights, surface and underground, are controlled by the State. The quality of the water is satisfactory for most purposes. Analyses of 19 samples, listed in the appendix, show the range in water quality at various plants throughout the State. Costs of delivering new water to current operations range from 2 to 26 cents per 1,000 gallons with an average of 10 cents per 1,000 gallons for power and maintenance. No firm costs for recirculating water were available; estimated costs range from 1.5 to 2.5 cents per 1,000 gallons. The mineral-product value of the entire Nevada mineral industry in 1962 was equivalent to $10 per 1,000 gallons of new water and $26 per 1,000 gallons consumed. Projection of the 1962 water requirements of the Nevada mineral industry indicates that the demand for new water will increase from 8.6 billion gallons in 1962 to 11.9 billion gallons in 1980, a 43-percent increase. Water requirements ill the year 2000 are estimated as 14.8 billion gallons, an increase over 1962 water demand of 78-percent.

Jan 1, 1966

By David C. Kraft

Helical piles and ground anchors were used to meet critical design and constructability requirements for an urban forest Canopy Walk at the Atlanta Botanical Garden, Atlanta, GA. The 12-foot wide pedestrian walkway path was to be nestled among the treetops of a forest, extending to 600 ft. in length, and soaring 40 ft. high above the forest floor. Of particular concern during construction was that the foundation system for the temporary steel shoring system had to be non-invasive to the subsoil, could not damage the forest floor, trees, root systems, or foliage, and upon completion of the concrete walkway pour, could be removed, again without disturbing the subsoil. Accubrace, Inc. designed and installed all the helical foundation types, as well as provided steel braces, typically used in Tilt-Up building construction, for the walkway project. The braces, some extending to 43 ft. in length, were used to provide lateral support against wind loads for the walkway form. In addition, the braces acted as secondary support for lateral loads during the placement of wet concrete along the 600 ft. length of the walkway. Helical foundation products installed included vertical compression piles, ground anchors for tension rods, and ground anchors for the braces. The installation of the piles and anchors was particularly challenging since the forest floor elevation varied as much as 50 ft. due to the presence of a ravine. Information is provided on the subsoil conditions, required loads, design, installation, and acceptance criteria for each helical product type installed for the project. The results of vertical and lateral load tests on the helical piles in the pre-construction phase, conducted in conformance to project specifications are presented. Photographs to illustrate the nature and complexity of the project are included. The concrete pour for the walkway was successfully completed on December 12, 2009, and the walkway was opened for visitors in May, 2010.

Jan 1, 2011

By C S. Szentesy, K Howie

The Rosia Montana gold deposit is located within the æGolden QuadrilateralÆ area in the Apuseni Mountains of Transylvania, Romania. The deposit is situated approximately 85 kilometres north of the regional centre of Deva, within the province of Alba, at elevations of up to 1100 metres above sea level. The Rosia Montana deposit contains a current resource of 344.07 million tonnes at an average grade of 1.3 grams per tonne (g/t) gold (Au) and 6.0 g/t silver (Ag) for a total (measured, indicated and inferred) contained resource of 14.29 million ounces of gold and 67.00 million ounces of silver. The resource was calculated using a 0.6g/t Au cut-off, a 10 x 10 x 10 metre block size and multiple indicator kriging. The low sulfidation style epithermal mineralisation at Rosia Montana is hosted within Tertiary age dacite intrusions and related vent breccias. Mineralisation is generally disseminated and associated with silica, adularia, illite, pyrite and carbonate alteration of host rocks, with minor late carbonate-base metal veins. Precipitation of precious metals is generally considered to have occurred as a result of over-pressurization, boiling and subsequent brecciation. The dacite intrusions are hosted in Cretaceous shallow marine and deltaic shales and slates, which overlie older Paleozoic sedimentary and metamorphic rocks within uplifted sections of oceanic sea floor.

Jan 1, 2002

The Porgera Joint Venture commenced production during September 1990. A small tonnage underground mine extracts high grade gold ore using small scale stopes. Conventional drill and blast methods are used for development and production mining. Ground support is effected with Splitset anchors, grouted rebar bolts and grouted cable bolts. Splitsets and grouted rebar can be installed by mechanised means. Vertical crater retreat, slot and massfire, and modified VCR stoping tech- niques are used at Porgera. Stopes are backfilled with a relatively strong cemented rockf ill. Future stope sequences require recovery of pillars beside and under filled stopes.

Jan 1, 1991

By Michael E. Henderson

The U.S. Bureau of Mines (BOM) constructed the Hydraulic Transport Research Facility (HTRF) to investigate the hydraulic parameters relating to the transport of coarse coal. To achieve these goals in a timely and efficient manner, the Bureau contracted to Boeing Services International, Inc. (BSI) the responsibility of operating the HTRF and providing technical support. This data report is a summary of the testing and data results for the period from 16 September to 1 November 1983. The testing covered herein is for coarse 2-in by a (minus 50 mm) Pittsburgh Seam coal in a 12-in (3 00 mm) pipeline, at velocities ranging from 5 to 18 ft/s (1.5 to 5.5 m/s) and at concentrations ranging from 15 to 55 pct.

Jan 1, 1985

By R. E. Heithecker

In Kansas, almost every oil well drilled into a limestone formation is treated with hydrochloric (muriatic) acid upon completion. This is done to increase the potential capacity of the well and thereby increase its "daily allowable" production (see p. 9), to shorten the time required to produce the recoverable oil, and to increase the quantity of oil recovered ultimately from the reservoir. The porosity and. permeability of limestone formations seldom are uniform throughout the proved area, consequently the production capacities of completed wells vary considerably. Acid treatment of wells tends to increase production capacity and to equalize potential capacity. If offset wells already have been treated with acid, new wells usually are treated to protect the property on which they are drilled against drainage. Even though competitive conditions do not exist in a field, it

Jan 1, 1939

By James W. Estep

The sulphur shortage that has occurred in the past two years has directed attention more and more toward sour natural gas reserves, Wellhead values of sour gas vary widely depending upon the acid gas composition, location, market conditions, and necessary processing charges. Preparation of a saleable residue gas is considerably more involved and expensive than that normally encountered in treating a sweet gas. Recent revisions in sales gas specifications have increased capital costs and processing charges. The presence of hydrogen sulphide and carbon dioxide in a natural gas contributes to shrinkage factors that may approach 50%. Fuel required by the gas sweetening process and sulphur slant tail gas incineration also contributes to a further reduction in the volume of residue gas available for sale. The additional processing facilities involving gas sweetening, mercaptan removal, expanded utilities, sulphur recovery and sulphur handling, all demand additional operating and maintenance staff. A favorable sulphur market under certain conditions may justify the processing of sour gas whereby sulphur is either a by-product or a co-product, Five typical cases involving different compositions of sour gas are presented for evaluation. Capital costs, operating problems, and operating costs are presented in detail for full economic evaluation

Jan 1, 1967

By G. H. Sedahmed, S. A. Nosier, M. H. Abdel-Aziz, A. A. Mubarak, M. A. El-Naggar, E. G. Abdel-Aziz

The performance of a rotating fixed bed reactor in recovering copper from industrial waste solutions by cementation is studied under various conditions. The rotating fixed bed is made of stacked woven steel screens to take advantage of two features of screens: the ability to present large area per unit volume and their ability to promote high turbulence. Variables studied are initial CuSO4 concentration, bed rotation speed, mesh number of the screens and bed thickness. The presence of baffles was found to increase the rate of cementation. The data were correlated by a dimensionless mass transfer correlation suitable for the design and operation of large scale cementation reactors.

By G. H. Sedahmed, S. A. Nosier, M. H. Abdel-Aziz, A. A. Mubarak, M. A. El-Naggar, E. G. Abdel-Aziz

The performance of a rotating fixed bed reactor in recovering copper from industrial waste solutions by cementation is studied under various conditions. The rotating fixed bed is made of stacked woven steel screens to take advantage of two features of screens: the ability to present large area per unit volume and their ability to promote high turbulence. Variables studied are initial CuSO4 concentration, bed rotation speed, mesh number of the screens and bed thickness. The presence of baffles was found to increase the rate of cementation. The data were correlated by a dimensionless mass transfer correlation suitable for the design and operation of large scale cementation reactors.

By Khaled Morsy

Cementitious seals are made of foamed cements with strength ranging from 100 to 600 psi. These cementitious seals are usually used at locations where the seal will be subjected to some convergence, assuming that this material can absorb entry closure without compromising the structural integrity of the seal. Prior to 2006, Lake Lynn Experimental Mine (LLEM) conducted full-scale tests on various cementitious seals designed to meet or exceed the 20-psi horizontal static load requirements of the old 30 CFR1 75.335. Both hydrostatic and dynamic loading tests were conducted. The structural response (pressure and displacement readings) obtained from these tests were recorded. The stability of the cementitious seal is based on balancing the load applied to the face of the seal from the explosion against the shearing resistance at the seal/rock interface. Therefore, the properties of the seal/rock interface, such as stiffness, cohesion, friction, etc. are critical to determine the stability of a cementitious seal. These properties are usually assumed by the researchers in their models. This paper emphasizes the importance of having the correct properties of seal/rock interface in the numerical modeling. FLAC 3D models were developed to simulate Celuseal2 cementitious seals subjected to both hydrostatic and dynamic loadings. Using the hydrostatic and dynamic loading test data conducted at LLEM, the static and dynamic properties of the seal/rock interface were back calculated. The FLAC 3D models showed good agreement with the test results.

Jan 1, 2009

By Panshi Xie, Xicai Gao, Yi Luo, Youfu Zeng, Yongping Wu, Shenghu Luo

This research investigates roof deformation and failure characteristics, as well as mechanical interaction between the panels of the roof strata above two adjacent working faces in a steeply inclined coal seam. Physical modeling with photogrammetry measurement method has been employed in this investigation. The movement of roof strata and section pillar, as well as the stratum morphological characteristics, was quantitatively analyzed. Results show that the roof movement direction above the two panels has zoning characteristics, especially in the lower panel. Roof migration in the lower panel of the working face is larger than that in the upper panel. The roof to floor closure perpendicular to the seam direction is larger than the sliding along the seam. The maximum roof concave and convex bending occurred at the middle and upper parts of both panels; the roof bending in the upper panel mining area indicates a larger mining disturbance induced by lower panel mining. The void ratio contour of the lower panel is an asymmetrically arched shape, which is different from that of the upper panel area. The higher roof strata above the upper panel exhibit separation and breaking, whereas the lower roof exhibits compression due to mining in lower panel. The section pillar is compressed and slides slightly, which aggravates the mechanical interaction between the panels and increases the caving height of the roof over the lower panel and the periodic weighting intensity

By Panshi Xie, Xicai Gao, Yi Luo, Youfu Zeng, Yongping Wu, Shenghu Luo

This research investigates roof deformation and failure characteristics, as well as mechanical interaction between the panels of the roof strata above two adjacent working faces in a steeply inclined coal seam. Physical modeling with photogrammetry measurement method has been employed in this investigation. The movement of roof strata and section pillar, as well as the stratum morphological characteristics, was quantitatively analyzed. Results show that the roof movement direction above the two panels has zoning characteristics, especially in the lower panel. Roof migration in the lower panel of the working face is larger than that in the upper panel. The roof to floor closure perpendicular to the seam direction is larger than the sliding along the seam. The maximum roof concave and convex bending occurred at the middle and upper parts of both panels; the roof bending in the upper panel mining area indicates a larger mining disturbance induced by lower panel mining. The void ratio contour of the lower panel is an asymmetrically arched shape, which is different from that of the upper panel area. The higher roof strata above the upper panel exhibit separation and breaking, whereas the lower roof exhibits compression due to mining in lower panel. The section pillar is compressed and slides slightly, which aggravates the mechanical interaction between the panels and increases the caving height of the roof over the lower panel and the periodic weighting intensity

By Ekhlaq A. Khan

"The new third Bridge over Narmada River at Bharuch which was recently completed is characterized by some aesthetically appealing elevations of the pylon and large size of the deck. This paper gives an insight to design and construction technique adopted for foundation construction of Extra-dosed span - 3 rd Narmada Bridge at Bharuch over river Narmada, Gujarat. Site being located in intertidal zone had its unique geological characteristics and own set of difficulties during construction.INTRODUCTIONThe Indian subcontinent offers diverse subsoil conditions. With current modern and future trend of long span bridges the substructure design often demands large size foundations. The foundation of theses bridges are usually deep and large in size. The execution of such foundations in maritime environments often involves important temporary works, in order to provide a safe workplace, comply with environmental requirements and achieve high quality standards.Often Pile foundations are preferred solution now a days, but due to various statutory and environmental regulations their construction poses a challenge. With better equipment and corresponding quality control, construction of large diameter pile foundation has emerged as a faster and reliable option.OVER VIEW OF THE PROJECTThe first two lane bridge on NH-8 (Vadodra – Mumbai) known as Sardar Bridge was constructed in 1977, subsequently an additional two lane bridge was constructed in 1999-2000, 29 m downstream of the first. In view of rising volume of traffic and as part of upgradation of NH8, National Highways Authority of India (NHAI) proposed to construct 3rd new 4 Lane Bridge 100 m downstream of 2nd Narmada Bridge, based on Central Water and Power research Institute (CWPRS) study and recommendation.The general layout (fig. 1) of the 3rd Narmada bridge has 8 spans of 144 m and 2 spans of 96 m with total length of 1344 m, supported by132 nos. of 1.5 m diameter piles of about 50 m depth. The substructure has leaning “Y” shaped lower pylon of height 30 m together with cast in situ pier diaphragm. The piles are of M40 and superstructure & pylon of M50 grade of concrete."

Jan 1, 2017

By M. Mahan, D. D. Blue, O. C. Garst, F. Fraas, L. Fink

"Early in World War II it became apparent that the known bauxite re- serves might not be adequate to supply the demands of the American aluminum-producing industry, as the transportation of bauxite from abroad to this country might easily be interfered with by hostile action. Consequently, the Bureau of Mines set up an intensive, well-integrated program for the production of cell-grade alumina from low-grade domestic ores. This pro-gram of investigation covered the production of alumina from clay, alumite, red mud, and other low- and marginal-grade ores. In line with the Bureau's usual policy of conservation of natural resources, it was decided that the investigation should be extended to cover the production of alumina and other valuable byproducts from aluminum dross.Statistical information showed that during the year 1943-44, an average of 2,900 tons of aluminum dross was generated monthly. This dross, after partial removal of free metal, had an average metallic aluminum content of approximately 9 percent. Some of this dross was produced by the melting of alloyed aluminum; but a large proportion 1,700 out of 2,900 tons - was generated by two producers of primary aluminum, and the dross did not contain an great proportion of alloying metals. Compared with dross from other sources, this 60 percent of the country's capacity can be assumed to have relatively uniform composition. Moreovcr, the problem of collection and distribution can be minimized because of the relatively small number of plants included in the organization of these two producers of virgin metal.Except for large pieces of metallic aluminum that easily can be mechanically separated for remelting, this dross has been discarded and scrapped. Inasmuch as chemical analyses show that the alumina content of dross is far higher-than ordinary ores - 111 percent alumina equivalent in dross compared to 57 percent alumina in bauxite - aluminum dross is a far richer source of aluminum than any known naturally occurring ores. The discard, of this waste material during the war and reconversion periods would be unsound economically. The work reported herein describes tests at the College Park Station of the Bureau of Mines on the recovery of metal, alumina, ammonia, methane, and abrasive-grade corundum from dross."

May 1, 1946