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By Xihuai Gong, Hongshuang Di, Jianping Li, Ning Yan

In this work, we investigated the effect of the rolling process (warm-rolled or cold-rolled) on microstructure evolution and mechanical properties of 9Mn steel. After intercritical annealing at 670°C for 10min, both cold-rolled and warm-rolled microstructures are composed of ultra-fined austenite and intercritical ferrite. The austenite in warm-rolled sample includes two types of morphology, namely equiaxed and lamellar, which exhibits a wide distribution of grain-size. The incomplete recrystallization or recovery behavior of ferrite in warm-rolled and annealed sample results in higher yield strength and shorter yield point elongation. Moreover, the warm-rolled and annealed sample extends the TRIP-related work hardening over a broad strain range, resulting in a better combination of ultimate tensile strength and total elongation.

Oct 1, 2019

By W. A. Walker, G. W. Ostroot

An increase in the number of deep wells being drilled where extreme bottom-hole temperatures are encountered, and the anticipated drilling of wells where temperatures in the range of 500°F or higher may occur, has brought about a comprehensive investigation of cementing materials and of the techniques involved in their proper usage at these elevated temperatures. Included are developments in cements, retarders, weighting materials and other cement additives which make it possible to formulate a variety of compositions to help resolve the cementing problems of these extreme well conditions. The problems associated with the selection and testing of cements are discussed, and a resume of field results is included. Previous studies on strength retrogression indicate that caution should be exercised in the selection of a cementing composition for use in high-temperature wells. It now appears that, by the addition of silica flour as a stabilizing additive to certain cements, compositions covering a wide range of slurry densities can be designed to meet extreme well conditions without strength retrogression. Improvements in cement retarders make it possible to produce a four-hour thickening time at static temperatures up to 500°F. This temperature is considerably higher than conditions presently being encountered in drilling and completion work. Inert weighting materials, used to produce 20-lb/gal or heavier cement slurries, are reviewed. INTRODUCTION As the search for oil continues, the number of wells being drilled to depths of 10,000 ft or below has continued to increase over the past decade. During 1959, there were 50,893 wells drilled in the United States for a total of 209 million ft of hole. Of this total, approximately 4.45 per cent were drilled below 10,000 ft and 0.30 per cent below 15,000 ft, with a record depth of 25,340 ft recorded (Table 1). With the drilling of this record-shattering hole comes the question, "How deep can wells be drilled?".' Limitations with respect to equipment (surface and subsurface), cementing materials and techniques would cause some concern; however, a panel of experts have agreed that the U. S. oil industry has the equipment and know-how to drill a 50,000-ft hole. The greatest deterrent would be the 700°F temperature they would anticipate encountering at this depth. Although the number of wells drilled under what is generally considered hot-hole conditions (230°F and higher) has been relatively high, each well often presents distinctly individual problems and requires separate consideration and selection of special materials, techniques and equipment. At the present time there are over 30 additives and special cements available for use in "tailoring" a cementing composition for a specific well. It is not uncommon to use three or four different additives with the basic cement to produce the desired slurry characteristics. A generally accepted procedure is to make laboratory tests on selected cementing compositions prior to pumping them into wells deeper than 12,000 ft, or where static temperatures are in the range of 260°F or higher. In some instances, it is recommended that laboratory tests be made where less severe well conditions are encountered. Prior to selecting a cementing composition for a particular well, key personnel representing the operator, drilling contractor and service company should meet to determine that each individual is acquainted with every detail which might influence cementing results and to discuss the execution of the job. For cementing hot-holes, a number of factors must be evaluated before proceeding with the operation. Consideration must be given to the following. 1. Thickening time—The slurry must remain fluid for a sufficient length of time to allow displacement down the casing and up the annular space in a primary cementing job or, in squeeze-cementing, adequate thickening time for both the build-up of a satisfactory squeeze pressure and the reversing out of excess cement. The thickening time of standard retarded cements will often be too short under extreme temperature conditions, thus involving special formulations and requiring laboratory tests to determine the proper amount of additional retarder to obtain the desired pumpability.

By W. C. Sanborn

The Bureau of Mines program of investigation and development of domestic mineral deposits had as its wartime objective the most effective immediate utilization of these resources in the interest of National security. Since the war, the results of individual projects are being prepared for publication as rapidly as practicable. Numerous chromite deposits were examined, among them those of the French Hill Mine in northern California. Situated 16 miles east of Crescent City, 76 miles from the nearest railroad shipping point at Grants Pass, Oreg., this deposit had a recorded yield of about l4,000 tons of metallurgical-grade chromite to the end of 1943. By the end of 1946, total production was more than 25,000 tons, averaging 43 percent Cr2O3, with a chrome:iron ratio of about 2.5:1.

Jan 1, 1948

By Abdelkabir Maqsoud

Different management options and rehabilitation strategies are available for mine wastes that produce acid mine drainage (AMD). One of them consists in building a cover with capillary barrier effects (CCBE) on the tailings to limit the availability of oxygen, an essential component of the chemical reactions leading to the generation of AMD. Prior to cover construction, a monitoring strategy must be established to evaluate the response and performance of the cover system. The key parameters to monitor should include matric suction and volumetric water content in the CCBE, oxygen flux (and/or oxygen concentration) through and below the cover, and the main meteorological parameters for the impoundment. In this paper, different techniques available to measure the targeted parameters are described and their main properties are given. Recommendations (based on existing cases) on the location and the number of monitoring stations and on the measurement frequency for each monitored parameter are also proposed.

May 1, 2007

By William Fink

NICKEL is used as an alloying element in several complex commercial aluminum alloys, among which are found some very interesting proper-ties, such as relatively high strength at elevated temperatures, relatively low coefficient of expansion, the absence of permanent growth, ability to take a good polish, and a bright, pleasing as-cast surface. For that reason the aluminum-nickel system was included in the list of binary aluminum systems that are being studied as a preparation for the investigation of more complex commercial alloys. This paper is the fifteenth of a series from the Research Laboratories of the Aluminum Company of America reporting the results of investiga-tions of equilibrium relations in aluminum-base alloys of high purity. The aluminum-nickel equilibrium diagram from 0 to 18 per cent nickel was determined, using the purest material available.

Jan 1, 1934

By Ruffles B. R

A computer simulation has been developed to model the flow of copper ore in Isa Mine. It simulates extraction of copper ore from the 1100 orebody by load-haul-dump (LHD) units to ore passes, haulage from chutes on 19 level by Rockflo trains to crusher bins, crushing and hoisting. It can assess in terms of the tonnage and head grade of ore hoisted, the effect of varying operating strategies, as well as measur- ing shortfalls in required capacities of any of the operations (extraction, hauling, crushing and hoisting). The simulation was designed as a modular, deterministic, steady-state model with parameter input allowing complete flexibility in its use. Queuing theory is used extensively to evaluate the effect of interference at potential bottlenecks. The model has been used to determine the effect on production of varying train sizes, maintenance policies on the haulage circuit, orepass capacities, and extraction operations.

Jan 1, 1974

By Robert H. Leach

SILVER the whitest of all metals, has been used for thousands of years. Students of antiquity agree that silver, gold, copper, and their alloys were the first metals discovered by man and they have all played an important part throughout the advance of civilization. Native silver has been found in different parts of the world in varying form and size, such as clusters of fine wires in rock cavities, thin sheets along cleavage planes in veins of rocks, and pieces of irregular shape that vary in size from extremely small particles to masses weighing many pounds. Nearly pure silver is found in, the native state but the native metal is more likely to contain copper or gold. Some of the natural alloys closely approximate the compositions of synthetic alloys that are used in the arts at the present time. As these native silver alloys usually are malleable and ductile, it is evident that prehistoric man was provided by nature with metals that he could work, with the crude tools at his command, into simple ornaments or other articles. The relative scarcity of silver combined with its resistance to attack under ordinary atmospheric conditions have been important factors in determining the purposes for which man has used it. Its scarcity and indestructible character have made its possession particularly desirable, and from the earliest times its principal use has been as a measure of wealth and a medium of exchange. The comparatively high value of silver in relation to other commodities makes it possible to transport a large amount of wealth in small bulk, and silver has traveled back and forth over all parts of the world. Even when made into ornamental pieces, such as bracelets,

Jan 1, 1953

By R A. Burwash

In the Yellowknife geologic province, 2,600-million-year-old granites are cut by three sets of diabase or gabbro dyke : (1) large dykes striking 70°E to E-W, (2) rare dykes striking N-S to 30°E and (3) an abundant swarm striking N 10°-300W. Preliminary potassium-argon dating has been carried out on whole-rock samples of the chilled margins and coarse centers of the dykes, and on mineral separates from the dykes and contact aureoles. Data from seventeen dated samples suggest that the dyke sets were intruded during three periods of basaltic magmatism -2,200, 1,500 and 1000 million years ago. The two earlier periods closely follow the time of emplacement of granites in the Yellowknife and Churchill geologic provinces. The latest diabase dykes occurring in the Yellowknife province are temporally related to a widespread basaltic magmatism, for which the term Keweenawan is not appropriate. D DRING the past ten years, methods of physical age determination have been widely applied to date the time of intrusion or metamorphism of Precambrian rock

Jan 1, 1963

By L. F. Tedsen, A. E. Flanigan, J. E. Dorn

SINCE aluminum-alloy sheet may be used occasionally at moderately elevated temperatures, the effects of temperature en the mechanical properties are of interest. Recently the short-time tensile properties of several high-strength materials have been studied at temperatures up to 375°F. This paper deals with stress-rupture and [ ] creep properties at the same temperatures. The work was done at the University of California as a portion of the project NRC-548. It was financed by the War Production Board and was supervised by the Office of Production Research and Development. This paper has been released for publication by the latter agency. The following materials were studied, all in the form of 0.040-in. sheet: Alclad 24S-T Alclad 24S-T8I Alclad 24S-T86 Alclad 75S-T R301-T (clad) [ ] Specimens were loaded in tension in the cross-grain direction. Testing temperatures included 94°F., 211°F., 300°F., and 375°F. Stress levels were selected to cause rupture in times ranging from several minutes to boo hr. In each test the following data were obtained: (I) fracture time, (2) elongation at fracture, (3) the complete strain-versus-time curve (creep curve), (4) creep rate (defined in a later section). MATERIALS Materials for specimens were obtained from the manufacturers' commercial

Jan 1, 1946

By T. G. Phillips

"This paper gives an inside look at a bulk terminal and describes the preparations that must be made by a company in developing such a terminal and its position in today's traffic pattern. The following headings cover the subject material: (a) Traffic pressures, their detection and measurement, (b) position in the traffic flow -selection of site, (c) transportation connections -present and possible future routes, (d) engineering studies and costs, (e) contracts, the basic material for insured traffic, (f) financing, (g) budgetary control, (h) development of new techniques, (i) growth into new cargoes or cargo-handling methods and (j) consolidation."

Jan 1, 1968

A series of petrological studies were carried out on the characteristics of alteration and mineralisation in mainly structural-controlled (Deep Star, Meikle, Deep Post) and predominantly lithological-controlled (Post-Betze-Screamer and West Leeville) gold deposits in the northern district of the Carlin trend, Nevada. Alteration and mineralisation in these deposits are hosted in a sequence of calcareous clastic units of the Devonian Popovich Formation, into which have been emplaced a number of Jurassic intrusions, and syn- to post-mineral Eocene dikes. Four hydrothermal events have been recognised in these deposits: an initial Devonian base metal system and early diagenesis; a Mississippian stage of alteration in conjunction with burial metamorphism; contact and hydrothermal alteration and base metal-gold mineralisation associated with the emplacement of the Jurassic intrusions; and a Carlin-style gold system related to Eocene magmatism.

Jan 1, 2004

By AIME AIME

THE non-ferrous alloys have been placed in the same class with steel by metallurgical research on hardening, and hardenable alloys of all metals except zinc are now manufactured. The hardening of the non-ferrous alloys is accomplished by a process of heating, quenching and ageing. R. S. Dean, head of the research department of the Western Electric Co., told of the results of this research in 'a lecture on "Recent Advances in the Art and Science of Fabricating Metals," given before the Missouri Mining and Metallurgical Association on Jan. 24, 1929.

Jan 1, 1929

By Peter G. Chamberlain

Domestic mining will not produce a significant portion of the manganese consumed in the United States unless new mining and processing techniques are implemented that will enable domestic lean ores to economically compete with rich foreign ores. One mining-processing technique that appears promising for certain deposits is in situ and/or heap leaching with aqueous SO2. Since leaching offers economic advantages of low capital costs, low operating costs, and short start-up times as well as environmental and safety improvements over conventional mining-processing, the Bureau of Mines studied the leachability of manganese deposits from several districts. Manganese oxides, hydroxides, and carbonates were leached to 80 to 90 pct recovery in 7 to 40 days of leaching with a solution containing 5 pct SO2 in column leaching tests. Preliminary cost analyses of surface mining-heap leaching, block caving-in situ leaching, and shrinkage stoping-in situ leaching indicate that the products of manganese leaching may be economically produced for the chemical and electrolytic manganese industries. The easiest marketable product to obtain would be a manganese sulfate commonly used as a fertilizer amendment. Manganese carbonates and hydroxides could also be precipitated from the pregnant leach solutions.

Jan 1, 1983

By L. E. Murr

Solution flow in leach dumps and heaps or in columns of representative rock has been the subject of only limited studies. This is a regime involving unsaturated flow in semiconsolidated rock with a wide size distribution. Even the concepts of continuous flow systems are fairly recent, and have evolved from the search for better methods of operating industrial chemical reactors. (1-3) Waste rock consolidation and permeability play a key role in solution flow characteristics. Harris (4) suggested that bulk density variations in a leach dump could alter the particle-to-particle contact, and that large particle aggregates could act like single, large particles . In the limiting case where the bulk density approaches that of the undisturbed, consolidated rock, the entire waste unit would behave as a single particle. Roman (5) treated the phenomenon of bulk density and its effect on consolidation in terms of lixiviant flow paths or solution channeling in leach dumps. Like Harris, he assumed that no solution moved through particles or particle aggregates associated with zones of high bulk density. Solution flow paths are thus effectively separated by particle regimes, creating solution channels in the waste body. While some attempts have been made to describe solution flow in leach dumps and related systems by utilizing computer model approaches and laboratory- scale simulations (5,6), there have been no direct, large-scale observations of solution movement in channels or of the actual channel sizes and distributions within a waste body. This paper describes a series of experiments involving large-scale, controlled waste leaching tests, conducted over a period of several years, and aimed at providing some direct observation of the changes in waste consolidation and permeability, the size and distribution of solution channels, the movement of such channels with continued solution application, and other features relating to solution flow during the leaching of low-grade waste. These results are then combined with mineralogical information to explain observed leach behavior.

Jan 1, 1981

By D S. Collins, Z Hosseini, I Pinnock, Y Toya

Microseismic monitoring is regularly used in the mining and geotechnical industries to provide detailed information about rock mass response to operational activities. This paper implements a variable 3D velocity model (VM) at a North American hard rock mine with the aim of further improving the accuracy of seismic event locations. A collapsing method is also used to help analyse two individual seismic event clusters at another North American hard rock mine. In the first case study, the location accuracy of events is shown to improve by moving from a conventional single VM to a variable 3D VM that accounts for voids and different geological domains. The modal average for the event location accuracy improved from 14 m to 5 m when the 3D VM was used. Additionally, the single VM failed to locate 26 per cent of the seismic events that were located by the 3D VM. In the second case study, the distribution of seismic events was further enhanced by using a collapsing method that highlighted planar structures. The collapsing method was performed on two large event sequences that occurred in close proximity and identified different seismic event distributions. One aftershock sequence aligned along a plane, suggesting an activated structure, while the other large event sequence had a more 3D distribution of events, suggesting a complex stress redistribution on smaller structures.CITATION:Pinnock, I, Collins, D S, Toya, Y and Hosseini, Z, 2016. Large event sequence analysis and 3D velocity models for seismic event location accuracy, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 879–884 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Tedsen L. F., Dorn J. E., A. E. Flanigan

since aluminum-alloy sheet may be used occasionally at moderately elevated ternperatures, the effects of temperature on the mechanical properties are of interest. Recently the short-time tensile properties of several high-strength materials have been studied at temperatures up to 3750°F.l This paper deals with stress-rupture and creep properties at the same temperatures. The work was done at the University of California as a portion of the project NRC-548. It was financed by the War Production Board and was supervised by the Office of Production Research and Development. This paper has been released for publication by the latter agency. The following materials were studied, all in the form of 0.040-in. sheet: Alclad 24s-T Alclad 24s-T8I Alclad 24s-T86 Alclad 75s-T R3oI-T (clad) Specimens were loaded in tension in the cross-grain direction. Testing temperatures included 94°F., 2II°F., 300°F., and 375°F. Stress levels were selected to cause rupture in times ranging from several minutes to 1000 hr. In each test the following data were obtained: (I) fracture time, (2) elongation at fracture, (3) the complete strain-versus-time curve (creep curve), (4) creep rate (defined in a later section). Materials Materials for specimens were obtained from the manufacturers' commercial

Jan 1, 1947

By Tedsen L. F., Dorn J. E., A. E. Flanigan

since aluminum-alloy sheet may be used occasionally at moderately elevated ternperatures, the effects of temperature on the mechanical properties are of interest. Recently the short-time tensile properties of several high-strength materials have been studied at temperatures up to 3750°F.l This paper deals with stress-rupture and creep properties at the same temperatures. The work was done at the University of California as a portion of the project NRC-548. It was financed by the War Production Board and was supervised by the Office of Production Research and Development. This paper has been released for publication by the latter agency. The following materials were studied, all in the form of 0.040-in. sheet: Alclad 24s-T Alclad 24s-T8I Alclad 24s-T86 Alclad 75s-T R3oI-T (clad) Specimens were loaded in tension in the cross-grain direction. Testing temperatures included 94°F., 2II°F., 300°F., and 375°F. Stress levels were selected to cause rupture in times ranging from several minutes to 1000 hr. In each test the following data were obtained: (I) fracture time, (2) elongation at fracture, (3) the complete strain-versus-time curve (creep curve), (4) creep rate (defined in a later section). Materials Materials for specimens were obtained from the manufacturers' commercial

Jan 1, 1947

By R. T. Elworthy

Canada ranks second in the list of world consumers of natural gas. In 1923 our production was nearly fifteen million thousand cubic feet valued at $5,800,000. Our output, however, appears very small compared with that of the United States, which in 1923 totalled over one thousand and eight million cubic feet, valued at $240,000,000. Natural gas is found in commercial quantities in three? provinces in Canada. New Brunswick: Natural gas in New Brunswick has been utilized commercially only since 1912,although the investigation of oil and gas possibilities of the province commenced as early as 1859. The annual production is a little more than one-twentieth of the total Canadian production and remains fairly constant from year to year. Ontario: In Ontario the earliest gas wells were drilled in Essex and Welland counties between the years 1885 and 1890. On account of the small demand in Canada the cities of Detroit and Buffalo were supplied with large quantities of gas from these wells, but this export was curtailed in 1898 and finally ceased in 1900. The production of natural gas in Ontario, mainly from fields in Lambton, Kent, Essex, Norfolk, Haldimand and Welland counties, increased rapidly from 1900 until the peak was reached in 1917, when over nineteen million thousand cubic feet valued at $3,641,587 was consumed.

Jan 1, 1925

By V. P. Mehrotra, D. W. Fuerstenau, A. -Z. M. Abouzeid

The use of pulverized coal for electric power generation results in the production of vast amounts of fly ash. One potential use for waste fly ash is the production of pellets for lightweight aggregates. This paper is concerned with the role of the physical and chemical characteristics of two different fly ashes in governing their agglomeration or pelletization behavior and their strength characteristics. In batch balling experiments, fly ash pellet growth was found to be extremely sensitive to the amount of moisture added. One ash (Mohave) exhibits marked pozzolanic activity whereas the other (Jim Bridger) does not. The pozzolanic activity has a very pronounced effect on pellet growth kinetics, moisture requirements, and the effect of various additives on growth kinetics. Slow drying under ambient conditions produces strong pellets from Mohave ash whereas Jim Bridger ash pellets lacking in pozzolanic activity are weak. Rapid drying at high temperatures results in weak pellets because water necessary for hardening is driven out of the pellet. Steam curing enhances pellet strength. Locked-cycle pelletizing experiments exhibit expected oscillation in pellet production rates and attendant fluctuations in pellet green strength.

Jan 1, 2004

By R. R. Brandenthaler

A series of open-flow tests was conducted in the Chickasha gas field, Grady County, Oklahoma, during June, 1927, under the direction of the U. S. Bureau of Mines and at the request of the Oklahoma Corporation Commission. The purpose of these teats was to determine whether or not any differences existed in the open-flow volume of a gas well when taken through well-head nipples of different diameters, and further, to establish if possible a relationship between open-flow volumes taken through well-head nipples of various diameters. The open flow of a well is the volume or quantity of gas, measured under standard conditions, that a well will produce when open to the atmosphere. There are several methods used for determining the open flow of wells; some of the methods are more suitable under certain conditions than others. The Pitot tube method is the simplest, is applicable to almost any condition, and is the one most commonly used. In the tests described in this paper no attempt was made to compare the Pitot tube method with the minute pressure measurement method or the orifice measurement method.5

Jan 1, 1928