Search Documents

By James G. Blaine, David A. Summers, L. John Tyler

There has been a considerable amount of research developed which shows that the close contour cutting of an excavation prior to removal of the central core will increase ground stability while concommitantly, reducing the number and size of blastholes required to create the excavation. To date, the industrial development of this technique has however, centered on the development of equipment based on simple cutter movement and mechanical rock cutting. The advent of reliable field operable high pressure waterjet cutting equipment with the very low reactive force required to hold the head in position has opened the way for a much smaller and more manueverable system. The advent of small, micro-computers allows the programming of accurate profiles for cutting tools on excavation equipment. The combination of these two technologies will allow the generation of complex as well as simple, excavation profiles and lead to the potential pre-support of the opening before major excavation is completed. A brief description of the necessary components and their functions is encorporated in the initial prototype design as given.

Jan 1, 1984

By Chingyuan Y. Li, C. Y. Hsieh

REALIZING that aluminum will have a great role to play in the coming industrialization of China, Chinese geologists have long been looking about for some aluminum deposits. The possible sources appear to be alunite, the alumina-rich shales, and the bauxite deposits. The locations of deposits are shown in Fig. I. ALUNITE Our attention was first directed to the alunite deposits along the southeastern coast of China. Table I summarizes the reserves now believed to exist in that region. [ ] Other alunite deposits have been found in Kiangpei, Szechuan province; Channing, Liuyang and Hsanshan, Hunnan province; Tsingchow and Chowyuan, Shantung province. No reserve figures are available. HIGH-ALUMINA SHALE Shale high enough in aluminum to serve as a source of that metal has been found in northeastern China (Table 2). [ ] In Manchuria, the Manchuria Light Metals Co., at Antung and Fushun, operating under Japanese control, has been the only active producer of aluminum. It is not known, however, whether the company uses local raw materials or imports ore from elsewhere.* SHANTUNG BAUXITE Bauxite was first recognized in China at Paoshan, Shantung province. Although the reserve is reported to be large (estimated at 271 million tons), the high content of insoluble residue (Si02) and mineral composition (diaspore) are dis-

Jan 1, 1946

Jan 9, 1951

By Samuel B. Christy

" The man is always greater than his work." The training of the men who are to develop the mineral resources of the world is the most important problem connected with mining engineering. It becomes ever more important to civilization as the mineral wealth of the earth approaches exhaustion. I have therefore decided to consider a few of the more important problems arising in the training of the mining engineer, and especially those arising in America. , The Peculiar Nature of Mineral Wealth. Mining and Agriculture are the two fundamental arts. Without the latter our existence would be precarious; without the former, our civilization impossible. Agriculture furnishes that regular supply of food and raiment which leads to the growth of large communities in which cultivated leisure first becomes possible; while mining furnishes the metallic thread from which is woven that complex fabric we call civilization. But in these two arts the conditions for success are widely different. Most of the crops that the farmer reaps may be harvested year after year, and the proper fertilizers being added, he may continue the annual harvest indefinitely, while, as a result of cultivation, his farm becomes yearly more valuable. But the crop the miner reaps can be harvested but once in the history of the race. Our mineral wealth has taken unknown ages to mature in the bosom of the earth. The ripened fruit can be plucked but once. There are no fertilizers for worked-out mines. It never pays to work over a mine that has been

Jan 1, 1906

By John Devine

DURING the past few years the Bureau of Mines has been studying hydrogen-sulfide corrosion in the petroleum and natural-gas industries. Early work was confined to investigating the various practical, or operat-ing, factors that control the corrosion reaction when ordinary mild steel is being attacked. In that work it was shown that, if the optimum operating conditions1 are obtainable, . gas containing hydrogen sulfide can be handled at ordinary temperatures without serious corrosion resulting. However, frequently "sour" gas must be handled under other than optimum operating conditions, and combating corrosion then becomes a problem to be considered more during the construction of a system than during its subsequent operation. That is, where economi-cally practicable in such cases the designer will seek to substitute for mild steel other steels or ferrous metals more resistant to corrosion by hydro-gen sulfide. The comparative resistance of various commercial steels and alloy steels to corrosion by hydrogen sulfide at elevated temperatures has been reported systematically by previous investigators,2 but similar information for corrosion at ordinary temperatures is available only from scattered sources, representing different methods of testing. As the value of comparative corrosion tests depends largely upon the use of a

Jan 1, 1934

Jan 1, 1919

By W. F. Hosford, E. W. Kelley

Deformation studies have been conducted at room temperature on single crystals of magnesium and magnesium alloys with thorium and with lithium. Single crystals oriented to suppress shear on the easily activated basal slip systems were deformed by plane-strain compression. Compression along the C axis was accommodated by {1011} banding. Compression perpendicular to the unconstrained c axis activated {1012} twinning, and, after virtually complete twinning, deformation continued by {1011) banding in the twinned material. Compression perpendicular to the constrained c axis was accommodated by the simultaneous operation of (1012) twinning against the constraint and (1011 ) banding. Although this orientation was favorable for {1010)(1210) prism and {1011}(1~10) pyramidal slip, these modes were not observed in pure magnesium or in Mg-0.5 pct Th. However, {10i0)(1~10) prism slip was observed in crystals of Mg-4 pct Li during compression perpendicular to the constrained c axis. Fracture in all materials occurred parallel to (1124) or {l~il) depending on the orientation and composition of the specimen. THE mechanical behavior of the hcp metals is strongly anisotropic. Although several slip systems have been reported the slip is cpmmonly in the directions of closest packing, the (1210),' and this does not produce strains parallel to the c axis. Hence the inherent anisotropy. The deformation mode most easily activated in magnesium at room temperature is (0001)(1210)- basal slip. Also {1010}(1~10) prism slip and {1011)(1210) pyramidal slip have been reported, primarily at elevated temperatures.2"4 However, at room temperature the shear stresses to activate the prism and pyramidal modes are roughly a hundredfold greater than that required for basal slip.'j4 Thus prism and pyramidal slip may be expected only under special conditions of loading. Strains normal to the basal plane can be produced by twinning, however. Many twinning modes have been reported for magnesium,' with (1012) twinning the most common and relatively easy to activate. Magnesium can deform by (1012) twinning when stressed along the c axis jn tension, but not in compression. In contrast, (1011) twinning is activated by compression along the c axis and not by tension. In addition to primary twinning, secondary twinning or slip can occur within the reoriented material of primary twins.' In general at least five independent shear systems must be active to bring about an arbitrary shape change such as that in the individual grains of a deforming polycrystalline material.' Because basal slip can_ provide only two independent shear systems and (1012) twinning can only accommodate an extension of the c axis, other deformation modes must be active in magnesium for an arbitrary shape change to occur. The purpose of this investigation has therefore been to study the various deformation modes in magnesium at room temperature, with special emphasis on those modes that are less easily activated. The effect of the alloying elements, thorium and lithium, has also been investigated. In polycrystalline aggregates, unambiguous identification of deformation modes is extremely difficult and the direct evaluation of the resolved shear stresses to activate them is not feasible. On the other hand, uni-axial tension and compression experiments on single crystals may not activate some of the- deformation modes because basal slip and/or {1012) twinning cannot be suppressed in most orientations. However, it should be possible to activate all possible deformation modes using oriented single crystals and plane-strain compression. Identification of active deformation systems and evaluation of the resolved shear stresses required to activate them should be facilitated. Wonsiewicz and Backofen have recently completed an investigation of the plasticity of pure magnesium crystals at various temperatures utilizing plane-strain compression and selected crystal orientations. This technique has also been used in the present work. The seven orientations selected for study are indicated in Table I. Plane-strain compression along the c axis (orientations A and B) should activate some deformation mode _other than basal, prism, or pyramidal slip, or (1012) twinning. In orientations C and D, prism or pyramidal slip would be expected to take place. When the compressive load is applied perpendicular to an unconstrained c axis (orientations E and F) the three slip modes should be suppressed but not (10i2) twinning. In orientation G, basal slip should occur.

Jan 1, 1969

By Harry T. Hamilton

THE genial assistant to the president of the New York Trust Co. is the latest addition to the Institute's board of directors, having been elected at the March meeting of the hoard to fill the unexpired term of the late E. E. Ellis. Usually when a banker is appointed to the board of a company the reason is obvious; the difference in this case is that the New York Trust Co. has some of the Institute's money, instead of vice versa. But Harry Hamilton is not really a banker-at least not primarily. Frefluently big financial institutions have a good mining engineer on their staffs to keep them from financing too many "cats and dogs." At any rate Mr. Hamilton gave up his consulting practice in San Francisco back in 1927, to accept his present position in New York. Until then, from the time he graduated from Yale in 1904, lie was constantly engaged in mining operations of one kind or another in the West and in Mexico. His first job was at Christmas, Ariz., where lie did "sampling and miscellaneous work" for the Saddle Mountain Mining Co. The writer tramped up to, all over, and through that property one hog day many years later, when it was run by the Christmas Mining Co., and carp assure the reader that without doubt the young Yale graduate got some good experience and was well broken in. From there Mr. Hamilton went to Cananea for a time, and then to the Copper Queen, at Bisbee, where he was a valued member of the rigging gang. An assignment of assaying and sampling for the Shan¬non Copper Co. at Metcalf lasted for a few months and then he accepted a job for a year with the geological department

Jan 1, 1936

The discovery of nickel at the Wallace Mine in 1846, recorded in the Report of Progress of the Geological Survey of Canada, 1.848-49, was not the first find in the Sudbury mining district. As long ago as 1770 a company had been formed to work the rich deposits of, copper whose existence was then known. .But it was during the first mentioned year that, incited thereto by fresh finds and a favorable report by Mr. W. E. Logan, then Provincial Geologist, two [ ] groups of Canadians organized "The Montreal Mining Company and "The Upper Canada Mining Company." By the former company the Bruce Mines Location' was purchased and work was immediately commenced upon it. The Wallace Mine acquired by the Upper Canada Mining Company, was abandoned after a shaft had been sunk and a few test pits opened.

Jan 1, 1907

By M. C. Cheney

The active development of the vast East Texas oil field, the attendant effects of the rapidly increasing flow from its prolific wells and the efforts to bring order out of chaos precluded or dwarfed other oil development in Texas during 1931. In a paper by Dr. F. H. Lahee1 presented at the October, 1931, meeting, the early history of the East Texas oil field is described and the sequence of events in connection with its development and efforts to control its production up to Sept. 25 is narrated. At that time the Railroad Commission of the state reduced the production of the field to a maximum of 400,000 bbl. per day by restricting the allowable daily production per well to 185 bbl. By further reduction in the daily production per well to 100 bbl., the field was held below that maximum figure during the remainder of the year. Meanwhile, as a result of an injunction against the Railroad Commission, its authority in the field was superseded on Oct. 13 by the Governor of the state, and after that date production was controlled directly by his orders issued under authority of martial law. Suits to contest this authority were brought in the Federal courts and were pending at the close of the year. On March 5, 1931, as a result of the East Texas production, posted prices for Mid-Continent 40' A.P.I. crude slumped from $1.07 to $0.67. As East Texas production continued to mount, posted prices in East Texas were reduced to $0.37 on June 3 and $0.22 on July 8, although in that field most of the oil was sold for much less, bringing the producer and royalty owner as low as $0.025 per barrel. Northeast Texas To the information contained in Dr. Lahee's paper, it can now be added that the East Texas field has produced over 105,000,000 bbl. and registered about 3700 successful completions during 1931. There may be some merit to the recent prediction that a large part of the field will have passed its flowing period by the middle of 1932 unless

Jan 1, 1932

By Sidney Siegel, J. Gardner Brooks, Irvin R. Kramer

IN 1942 Grossmann1 proposed that the hardenability of a steel may be calculated from its chemical composition by considering the base hardenability associated with its carbon content and grain size and multiplying this base by factors for each element present. Since Grossmann's original publication, several investigators2-5 have reexamined the multiplying factors for the individual elements and in general have found that the multiplying principle is valid. However, some of the individual factor curves developed have been in poor agreement. Inasmuch as the carbon-factor curve obtained by Grossmann was dependent [ ] upon the factors for all the other alloying elements present in the steel, it logically followed that his results were in need of correction in the light of the new data available for manganese, silicon, and the other alloying elements. Furthermore, in order to avoid the possibility that errors in the manganese, silicon, or other curves might influence the carbon-factor curve, investigation of iron-carbon alloys containing little or no manganese and silicon was necessary. That the effect of carbon on hardenability was greater than indicated by Grossmann is shown by a comparison of the diameters of completely hardened rounds of iron-carbon alloys with the ideal critical diameter calculated from Grossmann's factors. These alloys have a greater hardenability in a hite quench than predicted by Grossmann's factors for an infinite quench (Table I). [ ] Among the other important variables that were in need of further investigation were the effect of deoxidation practice on the grain-size correction curves and the effect of stable carbide-forming elements on the depth of hardening. Most of the work by Kramer, Hafner, and Toleman4 was done on silicon-killed steels. It was not known whether Grossmann's grain-size correction curves, deter- mined on aluminum-killed steels, was valid when applied to steels with different deoxidation practice. More data on the

Jan 1, 1946

By Sunder S. Saluja

Man had to learn to break rocks as early as the Stone Age, when they formed his main source of raw material. He started with chipping and over the years has reached a stage where he can employ atomic blasts and break, with one blast, millions of tons of rock. In between these two extremes there have been several stages of development including firesetting, use of the expansion of water on freezing in chipped cracks in cold climates, the use of low or deflagrating explosive black powder in about the 17th century, the use of high explosives with the discovery of nitroglycerine in 1846 by Sobrero, followed by the monumental discoveries of the great Swedish scientist Alfred Nobel in the latter half of the nineteenth century. The attempts to develop a stronger and still stronger explosive force were accompanied by investigations to understand the mechanism of failure of rock so that the force could be used to the best advantage; the latter, of course, have lagged far behind the former. This is mainly due to the fact that the chemical reactions involving high explosives as well as the processes resulting in the breakage of rock take place at too great a rate to be studied with the equipment that has been only recently available. Moreover, the development of stronger explosive forces was prompted by military necessities in the past and competition, at present, among highly developed nations. With the development, however, of the new techniques such as micro- second photography, microsecond flash radiography, extremely high-speed movies, strain gage assemblies, electronic chronographs and other improved electronic techniques, the investigator has in the last decade or

Jan 1, 1968

By AIME AIME

THE session on milling methods on Monday afternoon.* with G. H. Clevenger, chairman of the Mining Methods Committee presiding, was well attended. However, none of the authors of the papers presented were present except Messrs. Taggart and Ince. The paper on "Elements of Operations of the Pneu¬matic Table," by Messrs. Taggart and. Lechmere-Oertel, was presented by Professor Taggart as was the paper on "Calculations in Ore Dressing," by Luyken and Bierbrauer, due to the absence of the authors.

Jan 1, 1929

By J. Kent Smith

Vanadium is generally spoken of as a rare element; but, even in the light of our resources as known a couple of years ago, this description could be accepted in a qualified sense only. In fact, vanadium is very widely distributed, being a constituent of most clays, while even caustic soda has been shown to contain almost regularly a minute proportion of it, although the quantity in each case is so small as to render impracticable the extraction of the metal therefrom with profit. The opening-up of a large deposit of vanadium sulphide ore in South America has put a new phase on the commercial outlook of vanadium, the technical value of which for the improrement of steel has been proved by rigorous scientific investigation. This sulphide ore has the following analysis: Per Cent. Vanadium sulphide,.39.84 Molybdenum sulphide,.1.57 Nickel sulphide,.........1.49 Iron sulphide,.........4.07 Arsenic sulphide,.. nil. Copper sulphide,.. nil. Manganese sulphide,..nil. Free sulphur,..30.57 Phosphorus,...nil. Silica,....13.60 Alumina,..........2.46 Combined water, 5.00 Carbonic acid, Lime, magnesia, potash, soda and unaccounted for, 100.00 Being a free-burning ore it is calcined with ease, losing 45 per cent. of its weight in the process. The calcined ore has the following analysis:

Jan 1, 1908

By J. D. Irving

In the summer of 1899 there appeared in the Black Hills Mining Review† a short note announcing the discovery of certain deposits of wolframite in the vicinity of Lead City and Yellow creek, Lawrence co., South Dakota.

Jan 1, 1902

By Henry F. Hebley

This paper brings within the compass of one comparatively brief article a general description of the situation concerning the nation's water resources. It touches upon the phenomenal growth in the demand for water supply and emphasizes the problems facing the coal industry both with regard to acid mine water drainage discharged from active and abandoned mines and the suspended solids discharged to the stream system from wet coal preparation plants. IT must always be remembered, with regard to the problem of water-borne industrial wastes, that stream pollution from any cause is just one factor in the comprehensive problem of water supply in modern times. Industries nonexistent 25 years ago are now flourishing, and supplies of water piped to homes and apartments, as well as the greater number of plumbing fixtures per dwelling and per building, have created an ever growing demand on the country's water resources. Indication of this rapid growth in demand is shown in Table I, which is quoted from Abrams. of Texas increased 287% and the water consumption 7000 per cent." The domestic load varies greatly, depending on the extent of the available supply and the habits of the community. According to the report of the President's Water Resources Policy Commission' the United States Public Health Service reported a national average of 127 gal per capita per day, varying from 60 gal in communities of 500 persons to 140 or 150 gal in cities of 10,000 or over. Other critical areas may be cited to illustrate the inter-relation between new industrial processes and the demands for water in the area where the new enterprise is located. Powell and Wilson have pointed out that during World War 11, in the vicinity of Louisville, Ky., a rapid expansion of industry took place, consisting of numerous synthetic rubber plants. The demand for water increased from 37 million gal per day in 1937 to 62 million gal in 1943. These heavy requirements drew down the supply stored in the water-bearing aquifers to such an extent that urgent plans for recharging were considered. Similar situations have developed in the Los Angeles area and in the vicinity of Texas City. Warne4 has drawn attention to the situation in Los Angeles area, where in the West Basin the withdrawal of ground water in 1945 was 90,000 acre-ft, almost double the amount of the natural fresh water recharge. The draw down has been so severe that the level of the ground water is now below sea level, and sea water is invading the West Basin aquifers at rates up to 300 ft per year. In the Report of the Engineers Joint Council it is pointed out that in the area of Texas City the ground water table has been critically lowered. In 1930 the daily withdrawal from the water-bearing aquifer was 0.5 million gal. By 1945 the quantity withdrawn

Jan 1, 1954

By George A. Packard

THE experiments here described were made under my supervision while temporarily acting as head of the Department of Metallurgy at the Missouri School of Mines, at Rolla. The work was done by Messrs. W. E. Brown, W. C. Richards, and F. L. L. Wilson, and the description of the results forms a portion of a thesis presented for the degree of Bachelor of Science. These results are submitted because I have seen no description of the application of pot roasting to the treatment of a copper-concentrate. This work followed that already described in the discussion of the ' Lime-Roasting of a Galena-Concentrate,"' and was similarly occasioned by the lack of a furnace of the reverberatory type in which the copper-concentrates could be smelted. The material for the tests was a mixture of three lots available. The first consisted of 8-mm. jig-concentrates and the second of 0.5 mm. table-concentrates, from the San Juan district, Colo. Both contained pyrite, chalcopyrite and galena. The third was a lot of copper-ore, found in the laboratory, which had been crushed through 8-mm. screen, and had at some previous time, before the laboratory roasting-furnace was torn down, received a partial roasting. The analyses of these ores are given in Table I. In order to determine the applicability of pot-roasting as to each lot of ore, and the effect of varying proportions of lime, six preliminary tests were made in a " size N " Battersea crucible, 9 in. high by 6 in. in diameter at top, with a 5/8 in. hole bored through the bottom. The crucible was set in the upturned elbow of a 2-in. pipe, the joint being luted with clay; and air was obtained from a receiver supplied by a compressor. The

Jan 1, 1908

By George Beavers

FLASH roasting of iron concentrate is in the experimental stage at Copperhill. The problem is peculiar in that the iron concentrate is predominantly pyrrhotite; the ratio of that mineral to pyrite being 5 to 1. Results so far indicate that the heat, generated in roasting a material containing 52.0 per cent iron and 38.0 per cent sulfur, requires special handling and for this reason the installation costs per ton of roaster feed may be too great to compete with hearth roasting. Interesting features of flash roasting at Copperhill are: 1. The sulfur dioxide content of the roaster exit gas can be varied between wide limits. Eight per cent sulfur dioxide gas, with 1.30 per cent sulfur in the calcine, has been common practice and gas up to 13.0 per cent sulfur dioxide has been possible. 2. Temperatures of the exit gases are very high. When roasting 60 tons or more of iron concentrate per 24 hr. in a modified Wedge roaster, the temperature in the roaster rises to 2000° F. and the calcine is lowered to 0.20 per cent sulfur. If the entire roaster system could be constructed to withstand such temperatures, ideal roasting conditions would obtain as regards sulfur elimination and tonnage roasted.

Jan 1, 1934

By Arthur V. Abbott

In a few places attempts have been made to introdnce some means of delivering heat from a central station. Probably Pittsburgh, through the advantages derived from its almost inexhaustible supply of natural gas, has made a more wide-spread success in this direction than any other city. From the gas-wells in the vicinity of that town an enormous supply of natural gas can readily be obtained at a pressure sufficient to force it many miles from its source and to distribute it to all consumers. Obviously, very few places have such natural advantages, and some other means must be devised, if it is desired to furnish heat in a location not supplied with gas-wells. Several plants have been introduced to deliver heat by

Jan 1, 1888

By V. J. Driscoll

A method is given for checking pore volume reserve estimates and transient water inflzix factors utilizing early well performance. Principal applications are based on the observation that there is a convenient transient time-range in terms of well spacing in which observed pressure drop will give a good indication of fluid-in-place. Primary quantity determined is a porosity-feet value applicable in the vicinity of an observation well. Checks on porosity or net pay thickness and permeability values also are obtained. These are particularly valuable in improving quality of interpretive factors entering into pore-volume reserve determinations for larger fields. In smaller fields, direct determination of total field reserves and approximate location of boundaries may be made in some cases. Well interference and production data plus a build-up curve on the observation well are needed. The build-up curve may be taken at any time. Field applications are given. The method can be applied with the completion of the second well on a new discovery or to older reservoirs by major changes in withdrawal rates from a local area. Appropriate test length permits results to be obtained with equal accuracy on widely spaced wells. Criteria for optimizing test conditions are given. Provision is made for various boundary and well effects including incomplete observation well build-up. INTRODUCTION Due to low quality data, initial pore volume reserve and water influx estimates may often vary by a factor of two or more from results obtained at a later date. Unfortunately, by conventional methods, more reliable answers from performance usually are not available until after most significant economic decisions have been made. Furthermore, in older reservoirs, uncertainties may still exist as to original oil-in-place, recovery factors and residual oil saturations due to incomplete or inaccurate performance data. This paper outlines situations and appropriate arrangements of basic transient theory whereby well interference data can be utilized to improve the quality of estimates under certain conditions. In addition to production data on offset producers, key information required is a measured pressure drop at an observation well, corrected for any incomplete build-up due to previous production, plus a formation capacity value derived from a conventional pressure build-up plot on the observation well. The method, as outlined, is strictly applicable only to a horizontal single-layered system of uniform rock characteristics containing a homogeneous fluid of low and constant compressibility. However, under the set of test conditions devised, requirements can usually be relaxed so that it should be applicable to most low permeability gas, water and undersaturated oil reservoirs. This is an area where more reliable information is certainly needed. BASIC CONSIDERATIONS A, B, C and F as subscripts or in the text refer to producing Well A, observation Well B, a more remote producing Well C and field boundary F. Combinations such as AB refer to distances and dimensionless times in terms of distances between these points, while single letters refer to distances and dimensionless times in terms of the well-bore or field radius. Equations covering definitions of quantities and complex situations are given in the Appendix. Key equations in practical units are given in Table 2. Transient Pressure Behavior Fig. 1 illustrates pressure drop at Point B with time due to initiation of a constant rate of withdrawal from Point A. This is shown as since a quantitative under-