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By Eugene McAuliffe

IT is not possible to include in this paper, limited as it is in scope, the many diverse steps toward the reduction of mine accidents that are taken in the mines that produce the nation's coal. Every coal-producing state has enacted laws covering proper mining practices, and the major portion of these are directly related to the safety of the mine employees. The United States Bureau of Mines, the American Institute of Mining and Metallurgical Engineers, The American Mining Congress, a number of national, regional and state organizations, as well as the coal technical press, have covered time and time again all of the "do" and "don't" phases of mine operation that bear on the important question of mine and employee safety. Within the past 15 years The Union Pacific Coal Co. has attempted to put into practice in its mines in southern Wyoming these many good recommendations, finding some value in all, and yet, to secure substantial results, the management found it necessary to resort in the end to what might be referred to as "extra-territorial" methods. It is the writer's purpose to show in this paper that marked and even extraordinary betterment can be brought about when employer and employee work together with due sincerity. In presenting our own experi-ence, one that has been duplicated in so far as results are concerned on numerous other properties, no theory of perfection of management exists; on the other hand, our organization feels that as long as our record of accidents remains as shown by even our latest and best performance we still have far to go. Safety work in some form has been carried on in and about the mining properties of The Union Pacific Coal Co. since the first mine was opened at the now long-abandoned town of Carbon, Wyo., in 1868. On June 30, 1903, an explosion and subsequent mine fire occurred in mine No. 1 at Hanna, taking 169 lives, and a second explosion occurred in tile same mine on March 28, 1908, in which 59 additional lives were lost. Looking back with impartiality on the causes leading up to these two unfortunate disasters, we can only conclude that shooting from the solid, the absence of adequate ventilation, rock dusting, the use of water at the face to allay

Jan 1, 1938

By W. A. Ver Wiebe

The year 1938, with a production of 58,784,250 bbl. from 18,790 wells shows a slight recession from the high peak of oil production reached the previous year, when slightly over 68 million barrels of oil was marketed. The previous high peak had been reached in 1917 with a total of 45,451,000 bbl. Another still earlier peak was reached in 1904, during which year slightly less than 5 million barrels was produced and sold. The production of gas, on the other hand, probably reached a new peak during 1938 with a total of over 60 billion cubic feet. This peak, however, was not the highest peak, for during the year 1908 over 80 billion cubic feet was produced. Between these two high peaks the production dropped down to 16 billion cubic feet in the year 1921. The number of wells drilled during the year totals 1569. This figure is somewhat lower than the figure given in several trade journals because it does not include wells that were deepened or recompleted in a different geological horizon. Nearly three-fourths (or 1107) of the total number of wells were completed as commercial oil wells (915 in western and 192 wells in eastern Kansas). The commercial gas wells completed number 50, of which 4 are in eastern Kansas and 46 in western Kansas. The remaining 412 completions include 130 dry holes in eastern and 282 dry holes in western Kansas. Based on daily potential capacity, the new discoveries of the year accounted for 70,000 bbl. of new oil for eastern and 1,220,000 bbl. of new oil for western Kansas. It is interesting to note in this connection that the number of wells completed in the state rose gradualIy to a first peak in 1904, when 2782 were drilled. The number dropped off rapidly to 368 three years later, but rose to the second and highest peak in 1918 when 4671 wells were completed. In the period between 1904 and 1912 more gas wells than oil wells were completed. Between the high peak of 1918 and the somewhat lower peak in 1937, the low point was reached during 1931, with the completion of only 470 wells. In the matter of new pools discovered, Kansas again ranks high. The exact number depends somewhat upon the interpretation of a new area whether it should be called a new pool or a long extension of an

Jan 1, 1939

By W. A. Ver Wiebe

The year 1938, with a production of 58,784,250 bbl. from 18,790 wells shows a slight recession from the high peak of oil production reached the previous year, when slightly over 68 million barrels of oil was marketed. The previous high peak had been reached in 1917 with a total of 45,451,000 bbl. Another still earlier peak was reached in 1904, during which year slightly less than 5 million barrels was produced and sold. The production of gas, on the other hand, probably reached a new peak during 1938 with a total of over 60 billion cubic feet. This peak, however, was not the highest peak, for during the year 1908 over 80 billion cubic feet was produced. Between these two high peaks the production dropped down to 16 billion cubic feet in the year 1921. The number of wells drilled during the year totals 1569. This figure is somewhat lower than the figure given in several trade journals because it does not include wells that were deepened or recompleted in a different geological horizon. Nearly three-fourths (or 1107) of the total number of wells were completed as commercial oil wells (915 in western and 192 wells in eastern Kansas). The commercial gas wells completed number 50, of which 4 are in eastern Kansas and 46 in western Kansas. The remaining 412 completions include 130 dry holes in eastern and 282 dry holes in western Kansas. Based on daily potential capacity, the new discoveries of the year accounted for 70,000 bbl. of new oil for eastern and 1,220,000 bbl. of new oil for western Kansas. It is interesting to note in this connection that the number of wells completed in the state rose gradualIy to a first peak in 1904, when 2782 were drilled. The number dropped off rapidly to 368 three years later, but rose to the second and highest peak in 1918 when 4671 wells were completed. In the period between 1904 and 1912 more gas wells than oil wells were completed. Between the high peak of 1918 and the somewhat lower peak in 1937, the low point was reached during 1931, with the completion of only 470 wells. In the matter of new pools discovered, Kansas again ranks high. The exact number depends somewhat upon the interpretation of a new area whether it should be called a new pool or a long extension of an

Jan 1, 1939

By C. K. Leith

QUOTING from Dr. Richard T. Ely:1 "Conservation, narrowly and strictly considered, means the preservation in unimpaired efficiency of the resources of the earth; or in a condition so nearly unimpaired as the nature of the case, or Wise exhaustion, admits. And broadly considered, it means more than the word itself implies, for it naturally includes an examination of methods Whereby the natural inheritance of the human race may be improved; and still more broadly considered, and as used in popular discussion, it includes a treatment of the effects of productive conservation methods upon distribution. "Conservation means a sacrifice of the present generation to the future generations Whenever it is carried too far. There is a sharp limit to the economic sacrifice that we may reasonably ask the private person to make for even the present Welfare, and the limit is still sharper when we come to consider the interests of future generations." In a paper on the iron ores of America, presented to the Pan-American Scientific Congress at Washington, I have emphasized the fact that the reserves of iron ores in the two Americas are enormously in excess of the requirements of the present generation, in fact, so large that no shortage is to be anticipated for many generations in the future; that a large part of the value of iron ores is put into them by man's efforts to make them available. This fact is fundamental for the intelligent consideration of- policies of conservation as applied to iron ore. As I interpret it, this fact makes it practically unnecessary that the present generation should make any especial sacrifice for future generations in the way of conservation of its iron-ore resources. Even if we were disposed to look forward to a period of 100 or 200 years, with a view to insuring the welfare of the people living at that time, it is doubtful whether any procedure we could now formulate would materially help them in the matter of iron ores, so large are the reserves available. In order that an appeal for conservation may be effective it must obviously favor the welfare of the present or immediately following generations; it must promise benefits to general and individual welfare during a period within the range of comprehension of the average man.

Jan 2, 1916

By C. Y. Garber

INTEREST in the sink-float plant operated by the Bunker Hill and Sullivan Mining and Concentrating Co. at Kellogg, Idaho, has recently been largely confined to the preparation and reconditioning of the galena medium. The ease and simplicity of these operations in a concentrating mill producing a flotation lead concentrate has occasioned enough comment to possibly justify a brief description. The subject is treated from an operator's viewpoint only; no effort is made to discuss it in a theoretical or technical manner. PLANT AT BUNKER HILL The sink-float plant was first operated in December 1941. It was built for the purpose of quickly increasing mill capacity with a minimum of equipment. It is the Huntington-Heberlein sink and float process using galena medium and is operated under license from the Sink and Float Corporation, New York city. Lead-zinc ore from the Bunker Hill mine is crushed to pass a I ¼ in. screen and is then washed and separated on vibrating screens having 4 ½ -mm. round-hole punched plates. The screen undersize, amounting to 33 per cent of the mill feed, is dewatered and sent to the ball-mill feed bins. The screen oversize goes to the sink-float plant, where 50 per cent of the oversize, or 33 per cent of the mill feed, is float, which is washed free of medium and disposed of as a tailing. The remaining 33 per cent is sink, which, after washing, is crushed to pass ½ in. and joins the undersize in the ball-mill feed bins. The normal plant capacity is 1700 tons per 24 hr. About 1.7 per cent of the total lead and 3.3 per cent of the total zinc in the feed is lost with the sink-float tailings (Table I). [ ] More complete descriptions of the H. H. process and Bunker Hill sink-float plant are given in several recent articles, listed at the end of the paper. PREPARATION OF MEDIUM AT BUNKER HILL New medium is made intermittently as needed, usually 12 hr. in each 6 days. A small portion of the current mill flotation concentrate is diverted from the lead cleaner cells to a I-in. vertical sand pump and pumped to a two-cell 36-in. Agitair flotation machine, where NaCn and ZnSO4 are added and the grade of concentrate is improved as shown in Table 2. Tailing from this operation is returned by gravity

Jan 1, 1946

All the Technical PUBlications and Preprints published in 1932 are available at Institute headquarters. They are also on file in public, university and technical libraries and, when so indicated in the list, may be found in the Transactions. Copies of the Technical Publications have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Insti-tute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Copies of Preprints may also be obtained from the Secretary's office. Additional copies are sold at the rate of 1 cent per page; minimum charge, 25 cents. Nonmembers may purchase the papers at the prices mentioned. Metal Mining Technical Publi- Title Author Meeting Trans. cation Volume No. and Page* 484-A.45 Propeller Type Mine Fan at Moose A. S. Richardson New York 102, 88. 95 F.52 Shaft. Butte. Montana (13) Feb.. 1932 487-A.46 Progress in the Improvement of Max H. Barber New York. Methods and Equipment at Feb., 1932 Open-pit Iron Mines on the Lake Superior Iron Ranges (9) Pre. Sand Filling through Pipes and Lucien Eaton New York, 102, 33, 41 Boreholes (9) Feb., 1932 Milling And Concentration 445-B.37 Soap Flotation of the Nomulfides Will H. Coghill New York. H.19 (18) J. Bruce Clemmer Feb., 1932 461-B.38 Principles of Flotation—An Experi- I. W. Wark New York. mental Study of the Effect of A. B. Cox Feb.. 1932 Xanthates on Contact Angles at Mineral Surfaces (48) Iron and Steel Division 447-C.81 Electrochemical Potentials of Nitri- Shun-ichi Satoh New York, fied Steels (31) Feb.. 1932 450-C.82 Reaistanoe of Iron-aluminum Alloya N. 9. Ziegler New York. 100, 267. 670 E.143 to Oxidation at High Tempera- Feb., 1932 tures (8) 451-C.83 Pressure Welding of Low-carbon C. H. Austin New York. Steela with Theoretical Con- W. S. Jeffries Feb.. 1932 siderations on the Mechanism of Such Welding (42) 453-C.84 Inclusions—Tbeir Effect, Solubility C.E.Sims New York, 100, 154, 176 and Control in Cast Steel (24) 0. A. Lillieqvist Feb., 1932

Jan 1, 1932

By Jos. J. Walsh

Ventilation within a coal mine is essential to the welfare of those employed therein, from the standpoint of health, safety, and efficiency. While the saving of life and the preserving of health are the chief reasons for ventilation, efficiency and production are increased. In spite of the fact that we speak of air as having a certain composition, the proportions of oxygen, nitrogen, and carbon dioxide are not fixed, but vary between small limits. The different elements are not chemically united, they are merely mixed and each is free and can be separated with little energy. For this reason air in the mine workings is seldom found in a pure state. Factors that necessitate ventilation in coal mines are those that change the composition of pure air. Contamination of mine air results from the burning of oil-fed flames, the use of explosives, the oxidation of coal, and the liberation of gases by the coal. The extent to which these factors exist governs the size and general plan of the ventilating applianccs required. An efficient ventilating system is one that will furnish air at the working faces in sufficient volume to dilute and render harmless noxious gases and at the same time maintain an oxygen content closely approaching that of pure air. In a well-ventilated mine, the oxygen seldom falls more than 0.5 per cent. below normal. The carbon-dioxide content of the air in the average coal mine will vary from 0.1 to about 0.8 per cent., which amounts are not harmful. Three per cent. of carbon dioxide in air doubles the frequency and the depth of breathing; it is plainly noticeable and if breathed continuously for several hours its effect would probably be harmful. Slight reductions in the oxygen content of the air, such as occur in well-ventilated mines, have no debilitating effect on the worker. A person not exerting himself would fail to observe any unusual physical effect in an atmosphere: containing 17 per cent. of oxygen. This condition, however, or even a condition showing an oxygen content below 20 per cent., would indicate poor ventilation and that the elements which tend to reduce the efficiency of the worker are present, namely water vapor and a high wet-bulb temperature.

Jan 1, 1923

By Charles Legrand

(San Francisco Meeting, September, 1915) THE problem of mine pumping is so much affected by local conditions, and those conditions are so liable to changes during the life of a mine, that the best system to use is difficult to determine. The experience of the;, writer has been that, in general, for copper mines, electric pumping is most satisfactory unless the quantity of water to be pumped is great or. the mine does not use electric power for any other purpose. As a rule, however, figuring on the cost of necessary power plant, the total cost of: installation is greater with electric pumps than steam- pumps. As the water is liable to be gritty, outside-packed plunger pumps are to be recommended, and if the water is not acid, or only slightly so, chilled cast-iron plungers pay for their extra cost very quickly in diminished cost of packing. With chilled plungers it is possible to use metallic, packing instead of soft packing, if the water, is not too gritty nor the lift too high. In vertical pumps this packing is satisfactory for lifts up to 400 ft., in the experience of the writer; and may be found satisfactory for higher lifts. For water slightly acid, cement-lined pump bodies have given good satisfaction. For acid. water, both plungers and pump bodies should be made of acid-resisting bronze. For high lifts, especially with gritty water, a satisfactory pump valve is difficult to find. To reduce the unbalanced pressure on the valve at time of opening it is advisable to have narrow seats; this, however, brings high pressure on the seats when the valve is closed. On large valves for lifts of 600 to 1,000 ft. we have used leather, hard rubber, vulcanized fiber, and soft brass; for clear water the latter has given best satisfaction. The difficulties due to grit make it advisable to have large sumps where water can settle, and if possible, to have two of them so that they can be cleaned alternately. At the mines of the Old. Dominion Copper Mining ,& Smelting Co.; Globe, it was found that a small air. ejector discharging into a mine car is a very convenient way to clean mud and sand from a sump. .

Jan 9, 1915

By Jos. J. Walsh

Ventilation within a coal mine is essential to the welfare of those employed therein, from the standpoint of health, safety, and efficiency. While the saving of life and the preserving of health are the chief reasons for ventilation, efficiency and production are increased. In spite of the fact that we speak of air as having a certain composition, the proportions of oxygen, nitrogen, and carbon dioxide are not fixed, but vary between small limits. The different elements are not chemically united, they are merely mixed and each is free and can be separated with little energy. For this reason air in the mine workings is seldom found in a pure state. Factors that necessitate ventilation in coal mines are those that change the composition of pure air. Contamination of mine air results from the burning of oil-fed flames, the use of explosives, the oxidation of coal, and the liberation of gases by the coal. The extent to which these factors exist governs the size and general plan of the ventilating applianccs required. An efficient ventilating system is one that will furnish air at the working faces in sufficient volume to dilute and render harmless noxious gases and at the same time maintain an oxygen content closely approaching that of pure air. In a well-ventilated mine, the oxygen seldom falls more than 0.5 per cent. below normal. The carbon-dioxide content of the air in the average coal mine will vary from 0.1 to about 0.8 per cent., which amounts are not harmful. Three per cent. of carbon dioxide in air doubles the frequency and the depth of breathing; it is plainly noticeable and if breathed continuously for several hours its effect would probably be harmful. Slight reductions in the oxygen content of the air, such as occur in well-ventilated mines, have no debilitating effect on the worker. A person not exerting himself would fail to observe any unusual physical effect in an atmosphere: containing 17 per cent. of oxygen. This condition, however, or even a condition showing an oxygen content below 20 per cent., would indicate poor ventilation and that the elements which tend to reduce the efficiency of the worker are present, namely water vapor and a high wet-bulb temperature.

Jan 1, 1923

By R. E. Ogilvie, H. C. Gatos, R. E. Hanneman

The effect of high pressure on the stability of the (any phase transformation in the Fe-V system was studied by experimental and theoretical methods. The maximum solubility limit of the y loop of the atmospheric phase diagram was found to increase by a factor of five at 40 kbars pres-sure. The solubility limits of (Y and y phases are calculated on an approximate thermodynamic basis at pressures of 20, 40, and 50 kbars as a function THE high-pressure behavior of the a =^ y transformation in iron and iron-base alloys has been the subject of considerable interest recently. For those binary or higher-order alloy systems possessing a closed y loop, the effect of pressure is to extend the region of solubility of the more dense y phase. Although quite accurate calculations have been made of the a y temperature-pressure diagram of pure iron,' only very approximate thermodynamic calculations or experimental measurements have been made of the pressure dependence of a ^ y equilibria in binary systems exhibiting a y loop.2"4 of temperature and are found in excellent agreement with experimental results. The experimental high-pressure phase diagrams were determined using binary diffusion couples diffused under simultaneous conditions of high pressure and temperature and analyzed with an electron microbeam probe. Approximate calculations of the stabilizing effect of high pressure on the o phase are qualitatively confirmed by experimental results. These previous calculations have primarily dealt with the slopes of the allotropic a (Y= y phase boundary at terminal solubility. The lack of detailed understanding or accurate experimental results of the pressure dependence of the two-phase a ^ y field has been due, in part, to the types of experimental methods previously employed. The primary purposes of the current paper are twofold: 1) to develop and make use of thermodynamic expressions with the aid of supplementary data, to approximately calculate the pressure dependence of the entire y loop and the two-phase ((Y + y) width in the Fe-V system; and 2) to accurately determine the corresponding experimental high-pressure phase diagrams. The current paper describes the powerful method used which enables the simultaneously measurement of phase equilibria and diffusion under high pressure and temperature. A second paper, part 11, will deal with the effect of high pressure on binary diffusion in the Fe-V system.

Jan 1, 1965

By W. H. Kantner

In this paper, no attempt will be made to theorize on subsidence. Only known data and actual facts will be given, with a few exceptions noted where other factors and outside influences tend to change subsidence directly resulting from porphyry caving. The area under observation is known as the Southeast Extension of the East orebody. The orebody is irregular in outline and dips to the south and the east, extending in depth from about 425 ft. below the surface to 1050 ft. below the surface. In the upper horizon, the orebody is about 400 ft. long and 150 ft. wide. At 720 ft. below the surface, the ore outline is approximately 450 by 170 ft.; 70 ft. below this, it is 500 by 110 ft., with an extension at the north end to the east 270 by 120 ft. From this elevation to about 900 ft. below the surface, the ore spreads out to the cast and south, being about 700 by 500 ft. between these vertical limits. Below this it pinches out and at 1060 ft. below the surface is only 100 by 100 ft. The nearest point of the orebody—which is on the northwest side—is 600 ft. 'southeast of the Sacramento shaft. The country rock is all porphyry. Fig. 1 is a vertical east-west section showing orebody and original surface. The surface over the orebody was fairly regular and in this area and adjacent to it were portions of the surface plant, roads, and the main plant railroad to the concentrator. Fig. 2 is a map of the surface over the porphyry area. Caving operations started in April, 1925, at the approximate top of the orebody. The first lift was on the 600-ft. level; the ore was extracted by means of the Morenci timbered slide method and was from 425 to 455 ft. below the surface over an area of about 22,000 sq. ft. This lift was finished in May, 1926. The second lift, on the 650-ft. level, was already in production by May, 1926, so extraction of ore was continuous. This lift was 48 ft. high and covered an area of about 30,000 sq. ft. The ore from this lift was extracted by means of a modified Morenci timbered slide method. This lift was finished in March, 1927. The direction

Jan 1, 1934

By W. H. Young, P. D. Torrey

The Eastern fields comprise a distinct geological and geographical unit, located in the northern part of the Appalachian geosynclinal prov-ince. In this area are the fields of New York, producing from rocks of Devonian, Silurian and Ordovician age; the fields of western Pennsylvania, where oil and gas occur chiefly in rocks of Mississippian and Devonian age; the fields of eastern Ohio, where oil and gas are obtained from rocks of Pennsylvanian, Mississippian and Silurian age; and the fields of West Virginia, where oil and gas are produced from rocks of Pennsylvanian, Mississippian and Devonian age. Many of these fields are of great antiquity in comparison to the age of the producing areas in a greater part of this country, and consequently in most instances it is impossible to obtain accurate historical statistics. In addition, the records of many of the more recently discovered fields are either unobtainable or are not sufficiently reliable to justify their incorporation in a review of this character. Rather than overemphasize certain fields and areas, where complete records are available, when there are many other fields of equal importance for which statistical data are not available, the authors have made a tabulation of development that does not take into consideration past operations and production. The records utilized in preparing this paper were derived largely from the scout reports of several of the larger companies, which generously made them available to the authors. These were independently tabulated by counties and townships, in order to eliminate as far as possible duplications and, excepting the Clinton fields of Ohio, where many of the smaller wells have not been individually reported, they represent the most accurate information available. Market conditions in both the oil and gas industry were far from favorable during 1932 and in consequence there was a total decline in drilling in the Eastern States, which is 22 per cent less than the number of completions in the preceding year. This decline was not constant over the entire area, as is shown in Table 1. The oil fields of both New York and western Pennsylvania were the scene of renewed drilling activity, which was largely restricted to the water-flooding operations in the Bradford and Allegany fields. Practically no new operations were started, but a certain number of new wells

Jan 1, 1933

By George Rice

SOME form of longwall mining is generally used in Continental Europe; also in Great Britain where the coal is weak and friable, or the coal bed provides material for pack walls and filling, or where the bottom is soft and squeezes up easily, or the roof is pliable, or the bed is thin and brushing provides building material, or the thick multiple seams are mined in layers, such as the 24-ft. seam at Weymss, Scotland or the 10-yd. pitching bed near Coventry, England. Pillar methods have been retained in British fields where the coal beds are from 5 to 9 ft. (1.5 to 2.7 m.) thick, and free from thick partings or binders or without draw slate, which would provide waste rock for pack walls, or where the roof is hard and requires shooting to bring down and also the bottom or floor is comparatively hard. The room-and-pillar system, by which probably 95 per cent., of the coal of the United States is produced, is now found in only a few mines in Wales, where it is known as the pillar. and .(single) stall method. The American room-and-pillar system is not equivalent to the bord-and-pillar or stoop-and-room system. The essential difference between the bord-and-pillar and the average American room-and-pillar system is probably due to natural conditions. The majority of the coal mines in the United States have a depth of less than 700 ft. (213.m.). The bulk of the coal mined in Europe comes from a depth of more than 1200, ft., while the deepest mines in Great Britain, Belgium, and France reach 3500 to 4000 ft. In deep workings wide spans are impracticable, even with the use of abundant timber; accordingly, as the mines in the United States become deeper the rooms will become narrower and the pillars thicker, and the bulk of the coal will be extracted on the retreat. It is generally conceded, without reference to the cost of production, that the larger the pillars left on the first mining, the more thoroughly can the, coal be extracted. In Europe complete extraction is generally compelled either by the lessors or by the governments; whereas in this

Jan 2, 1921

By Ralph J. Schilthuis, William Hurst

The nature of the forces that are important in producing the oil in the East Texas field and the manner in which these forces are affected by the rate of production have always been problems of outstanding interest. These questions are of great interest to the industry as a whole on account of the economic importance of the East Texas field and to the engineers in particular on account of the unique character and behavior of the field. Subsurface pressure data throughout the field have been collected systematically, so that a quite complete history of the reservoir pressures has been kept as the field has been developed and produced. Subsurface samples of the oil and gas have been taken and these have been examined to obtain data on the physical properties of the reservoir fluids under the actual conditions of temperature and pressure. All of these data have been valuable because they have afforded the basis for a careful study of the means by which the oil is produced. It is the purpose of this discussion first to point out several of the important facts revealed by the data mentioned and then to describe studies that have been made concerning the interpretation of these facts. Reservoir Pressure Data and Properties of Oil The reservoir pressure data on the East Texas field have shown conclusively that the pressures are readily affected by changes in the rate at which the field is produced. This can well be seen in Fig. 1, where the average reservoir pressures obtained from time to time are plotted with the daily production rates and the cumulative production of the field. It is noted that the average reservoir pressure has declined irregularly, depending upon the rate of production, from the estimated original value of 1625 Ib. per sq. in. to the value of 1228 lb. per sq. in. observed for Aug. 11,1934. The decline in pressure has been more rapid at the higher rates of production than at the lower rates. In contrast, the average reservoir pressure has increased, on several occasions, upon reduction of the withdrawal rate from a high value to a lower value. The reservoir pressure data have also shown that a definite gradient in pressure has existed across the field from west to east since the begin-

Jan 1, 1935

By Gerhard Derge

THE chemical and physical properties of slag systems are of special interest to metallurgists, for nearly all metals are in contact with molten slags during the primary reduction from their ores and then during the subsequent refining and alloying processes that determine their ultimate use, These processes are carried out at high temperatures and involve such complex chemical systems that fundamental scientific knowledge of the properties and behavior of these slags is inadequate. Various hypotheses have been proposed to explain known slag characteristics. The commonest of these regard the molten slag as constituted of compounds that are dissociated in varying degrees into their constituent oxides, as illustrated by Schenck1 and the recent papers of Chipman and co-authors.2-5 Another proposal is that these compounds dissociate by completes or partial ionization, the evidence for which has been reviewed by Martin and Derge.7 Whatever hypothesis is favored, the exact formulation of these compounds is incomplete. It is based on three principal types of information: I, Studies of solidified slag samples by X-ray diffraction, petrography, and similar methods that can be used at room temperature, The correlation of this information with the high-temperature properties of the molten slag is uncertain, 2. Studies of slag-metal equilibria, which have the advantage of providing observations on the molten slag at high temperature, However, even these data present problems of interpretation because they require a complete knowledge of the metal phase, 3, Direct measurements of properties of molten slag at the temperature of greatest metallurgical interest. Viscosity, electrical conductivity, specific heats, and similar properties have been measured, but the data of this type are widely scattered and frequently difficult to interpret, Additional direct measurements of properties of molten slag that can be interpreted in terms of chemical behavior are required, and this paper shows that the standard physical-chemical measurement of reversible electrode potentials, which measure the activity of specific constituents, is a fruitful source of such information, The purpose of this investigation, therefore, was to find an electrode combination that would yield reversible electromotive force measurements when dipped into the molten slag to be studied. Slags of the systems CaO-SiO2 and CaO-A1203-Si02 were chosen for study because graphite containers could be used and the data could be correlated with those for viscosity, conductivity, and other proper-

Jan 1, 1946

By George H. Ashley

At the beginning of the war, about 13 years ago, a conference was called in Washington to lay plans for pooling the coals of the United States. A careful review of the various systems of classification then extant showed none well adapted to the needs of coal pooling. The system of Tidewater pools then adopted, using numbers to distinguish one pool from another, was based on typical coals of different localities. At that time, the writer undertook the preparation of such a practical classification. Aside from drawing on his experience of over 20 years in the coal fields of the United States, reaching from the Pacific Coast and the Rio Grande to Rhode Island, he first examined and carded all of the large collection of coals in glass jars made by and for M. R. Campbell. Next, he carded all of the descriptions of coals he could find in the U. S. Geological Survey bulletins and elsewhere, as well as practical tests of coals by the Navy and other organizations and then took account of every published coal analysis of the U. S. Geological Survey and U. S. Bureau of Mines. A study of this information, involving thousands of recomputations, led to the presentation of a paper on "A Use Classification of Coal" before this Institute at the Chicago meeting, September, 1919. That classification was unique (1) in a classification based on "standard coal" which included moisture, but used standardized ash, sulfur and nitrogen, (2) in using physical properties to distinguish the major classes or orders, (3) in recognizing British thermal unit values in the minor subdivision, (4) in the large number of classes recognized (thirty-six), (5) in proposing mineral names for all classes, (6) in proposing a letter code for the several classes for practical use, (7) in proposing a code for expressing what has commonly been called "grade" of the coal, the grade code to be combined with the rank code to designate and describe a coal. The writer still thinks that the principles then offered, though not necessarily the exact proposals, are valid and desirable in any practical classification. The actual classification of coal by rank was based on the ratio of fixed carbon to volatile matter for the high-rank coals—the well-known

Jan 1, 1930

By Terje Preber

Undisturbed sampling of shale has always been difficult. As pert of a comprehensive subsurface investigation for a nuclear power plant in northwestern Illinois, the Maquoketa shale, which contains seams of argillaceous dolomite, was sampled using different coring techniques. Since the Maquoketa shale is extremely fissile, careful sampling preservation by both lateral and vertical confining was utilized. The samples were tested to determine both static and dynamic properties. A relationship between void ratio and compression index, swell index, and swell pressure ratio was established. Correlation was found between the dynamic properties and both undrained shear strength and confining stress. Based on the results of the sampling and testing programs, recommendations for sampling and sample preservation techniques are given. INTRODUCTION Undisturbed sampling and preservation of samples of weathered, fiasile shale is often a very difficult task. The often erratically varying degree of weathering with depth complicates sampling and makes reproducibility of testing results difficult. Therefore, the testing of weak, weathered rock very often yields a wide variety of test results with large data scatter. The reproducibility of teat results usually associated with water-deposited soils is seldom, if ever, obtained. The testing and sampling program described in this paper was part of a comprehensive subsurface investigation for a nuclear power plant in northwestern Illinois. The sampling, preservation and testing program of shale samples taken from the Maquoketa shale are described, and, in particular, the different sampling techniques and sample preservation procedures are evaluated with respect to their effectiveness. The samples obtained by these procedures were subjected to a comprehensive testing program, including both static and dynamic testing in order to provide input for soil-structure interaction analysis. GEOLOGY The Maquoketa Shale Group is of Ordovician age and is part of the Cincinnatian Series. The area where the shale samples were taken was in a broad sea far from sources of clastic sediments during most of Ordovician time. However, during Cincinnatian time when large deltas in the Appalachian region were being formed, clastic sediments from the east dominated the sedimentation ii. Illinois, resulting in formation of the shale and dolomite shales of the Maquoketa Shale Group (Willman et al., 1975). The geologic unit sampled consists of a greenish gray to gray silty shale containing numerous 1- to 12-inch (2.5- to 30.5-cm) thick interbeds of argillaceous dolomite. The dolomite comprises up to 40 percent of the profile studied. The shale

Jan 1, 1984

By F. C. Miller

The metallurgical fuel of Colorado, Utah, and New Mexico has been a Veiny tardy member in the caravan of western industrial progress. The history of western coke has naturally been closely related to the development of the metallurgy of iron and steel and the precious metals, in the State of Colorado. It was at Leadville, with a population of 300 in 1877, that the Sentinel was published by Richard S. Allen. The Sentinel gave very full accounts of the various mineral discoveries at the new town of Leadville, which found their way to the more widely circulated journals of the East, and attracted the attention of many people. At the close of 1878, a census slowed a total of 5040 persons. The first smelter was established in 1877, at Malta, two miles from Leadville, by A. R. Meyer, but was not successful. It was succeeded by the Harrison Reduction Works, in 1878. The La Plata began with one furnace in June, 1878, and in 1879 had four furnaces in active operation. These furnaces used charcoal for fuel, and, because of hot tops, suffered a tremendous loss in lead and silver. This difficulty was overcome by the erection of 50 single-bank 10-ft. beehive ovens at Crested Butte, Colo., in 1880. The slack coal sent to these ovens was very pure, and yielded a coke carrying as little as 4.5 per cent. ash. Among the pioneers in the Leadville district were Grant, Eddy, James, Billings, Eiler, and Dickson. To these men the West owes the present expansion of its mining industry, and the erection of metallurgical processes for the treatment of precious metals. On Mar. 1, 1876, Pueblo was connected to the Atchison, Topeka & Sank Fe by the Pueblo & Arkansas Valley branch. The first smelter was erected in Pueblo by Mather and Geist. This modest plant grew into the immense Pueblo Smelting and Refining Co., now a part of the American Smelting and Refining Co. Coke for these small furnaces was made from unwashed Engleville coal, in 186 single-bank 12-ft. ovens at El Moro, in the Trinidad district, and it was not uncommon for the percentage of ash to exceed the percentage of fixed carbon in the coke. On Jan. 23, 1880, the Colorado Improvement Co. consolidated

Jan 1, 1920

By Samuel Doak

THE utilization of rotary kilns, of the well-known cement type, for the preparation of iron ores, for the blast furnace, has become of considerable economic importance within the past 10 years in certain localities, notably those where the native ores are lean. Such kilns may be used simply for the agglomeration of ores too fine to be charged into the blast furnace (i.e., ores whose loss in the dust catchers is excessive, and whose fineness is detrimental to the working of the furnace), or for the desulphurization of lump and fine ores the sulphur content of which does not exceed 6 or 7 per cent. The desulphurizing action can be combined with that of agglomeration provided the kiln is sufficiently large. Other processes have been developed for the same purpose, but while I am not able to draw a comparison between them by reason of lack of sufficient data, it is safe to say that the kiln, if properly dimensioned for the character of ore to be treated, will compare favorably in its results, both as to economy and quality of product, with any other process. It is not, however, as well adapted for the treatment of flue dust, as is a sintering operation, on account of the large percentage of fine coke contained therein. Any combustible entering the kiln at its feed end renders the process very much more expensive and unsatisfactory on account of the difficulty of controlling the temperature, also because of the rapidity with which long "rings" form, due to the increased heat at the cooler end of the kiln. The greatest value of the kiln at present is in the treatment of pyrites cinder; that is, the residue from pyrites ore after the extraction of the greater part of the sulphur. This cinder, while high in iron content, has too much sulphur remaining in it to be allowed to form a large part of the blast-furnace burden, without further treatment. It will range in metallic iron from 42 per cent., representing a very low-grade cinder, from a domestic pyrites, to 64 per cent. of the residue from the best Spanish ore, and the corresponding silica content will vary from the maximum of about 25 per cent. to 1 ½ per cent. The residual sulphur depends largely on the type of burner used in the original desulphurization. In general, the leanest original ores retain the greatest amounts of sulphur. In

Jan 9, 1915

By W. A. Thomas

Steam is, and doubtless always will be, the basic power in the anthracite industry, either directly applied through engines and pumps or electrically. The rapidity with which electric power is being applied to the mining and preparation of anthracite leaves little doubt as to its utility and economy. There is practically no operation, except possibly the drilling of hard rock, that has not been successfully electrified and the matter of drilling is handled economically with electrically driven compressors and the standard compressed-air drills. Conservation and the seemingly ever-increasing cost of production, justify careful consideration of the possible results of the more extensive use of electric power in the industry. It is not planned to discuss, herein, the relative economies of individual applications but to consider the relative economy and flexibility of steam and electric power. The reports available for the year 1920 indicate a production of slightly over 80,000,000 tons of anthracite, of which 8,843,500 tons were used for power and heating purposes; in other words, over 11 per cent. of the production was used at the mines. Some of this was used to generate electric power at the mines, about 160,000,000 kw-hr., while 150,000,000 kw.-hr. was purchased from the public utility companies. One large producer, who is buying some electric power and generating some, used over 13 per cent. of the production for power and heating at the mines. Another producer, where considerable electric power is generated on the properties, is using less than 9 per cent. of the output for power and heating. One of the largest producers has a fuel consumption of over 15 per cent. of the output, besides which considerable power is purchased. A careful study of the field indicates that steam-operated plants use upwards of 13 per cent. of the production for power and heating, while electrically operated plants use about 1 per cent. for heating; so that, for steam-power purposes at least 12 per cent., or 268.8 Ib., are used for power out of each ton produced. In the complete electrification of anthracite mining operations, no set rule can be given for the power requirement, in kilowatt-hours per ton, as conditions vary widely in the matter of pumping, ventilation, and transportation, but the following cases are given as a basis of determining a range and a possible average power requirements:

Jan 1, 1922