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By S. D. Michaelson, Eric Sinkinson

Many of the magnesite ores of the western part of the United States contain such large amounts of silica and hydrous silicate minerals that the value of the ores is either low or nominal. Expensive and carefully controlled mining methods are necessary to prevent excessive dilution of the higher grade ores by introduction in mining of small pieces of the hanging walls or footwalls of the deposit. This difficulty is further complicated by the various states of decomposition of the country rock of the deposits in which many of the ores occur. The problem the authors attempted to solve arose from a request to float an impure magnesite containing varying proportions of siliceous gangue with calcium carbonate. The ore is normally enclosed in serpentine masses, somewhat decomposed, and in mining it wall rock is incidentally added, so that variable amounts of siliceous material occur in the samples. The silica, alumina, and iron oxide are so closely associated with the magnesium carbonate in the magnesite that ordinary mechanical separation at coarse mesh sizes is of no avail. It is well known that calcium carbonate can be floated by suitable reagents, therefore it seemed reasonable to suppose that magnesium carbonate minerals would behave in a similar manner, but experimental trial proved that this supposition was unfounded. Therefore the first step in the problem was to find out what differences of behavior there were between magnesium and calcium carbonates under flotation conditions, or when suspended in water. In water at 18" C. magnesium carbonate is slightly more soluble than calcium carbonate; in fact, MgCO3 is soluble to the extent of 0.0106 grams in 100 c.c. of water at 18" C. and CaCO3 to the extent of 0.0013 grams. However, magnesium carbonate in water gradually changes to the basic carbonates of a composition (3MgCO3.Mg(OH)23H2O) or (4MgCO3.Mg(OH)25H2O), depending upon conditions, and calcium carbonate to calcium hydroxide, Ca(OH)2. The relative solubilities of these hydroxides in water are the reverse of the solubilities of magnesium and calcium carbonates. The range in published figures for solubility

Jan 1, 1938

William B. Phillips, Birmingham, Ala.: The questions raised by Messrs. Wilkens and Nitze are in the highest degree interesting to owners of low-grade iron-ores, aizd no less so to blast-furnace managers. If it can be shown that ores heretofore considered worthless can be brought within the limit of economic use, many large and readily accessible deposits may come into market on the one hand, while on the other the possible increase in the output of the furnace per ton of ore used will prove of advantage to the iron-maker. It cannot, of course, be claimed that this process has been employed on a working-scale with respect to iron-ores, and in so far as concerns results on a large scale no one is any wiser than his fellow. Granting that the results obtained in an experimental way (and certainly the experiments were conducted with a great deal of care) can be attained in practice, we would still be facing the question, what it would cost to get them. In the absence of any specific data, we have to fall back on general principles, helped along, as far as possible, by indications afforded by the experiments. I must confess that as regards the Clinton ores, which I have studied to some extent, I am not sanguine of making a ton of 53 to 54 per cent. concentrates from less than 1.75 tons of 40 per cent. raw ore. It may be possible to get the iron in the heads to 56 to 57 per cent., but the lesser richness of the middlings will probably reduce this to 53 to 54 per cent. in the salable stuff. As the authors remark, it is not worth while to discuss the concentration of the better grades of " soft" Clinton ore; for the price at which they are now delivered at the furnaces, and the comparatively limited amount now remaining, render their concentration unadvisable. If it is to succeed in the Birmingham district, the process must be applied to the low-grade soft and hard ores now con-

Jan 1, 1897

By C. V. Millikan, C. V. Sidwell

There is nothing more important in petroleum engineering than a definite knowledge of the pressure at the bottom of an oil well at any existing operating condition, and the relation of this pressure to the pressure within the producing formation. A knowledge of bottom-hole pressures is fundamental in determining the most efficient methods of recovery and the most efficient lifting procedure, yet there is less information about these pressures than about any other part of the general problem of producing oil. Determination of Bottom-hole Pressures Bottom-hole pressure may be calculated or determined by several methods. On an inactive well it may be calculated from the fluid head or, if the well is shut in, by adding the casinghead pressure, the static head of the gas and the fluid head. In wells flowing naturally through tubing the pressure at the bottom of the tubing may be calculated by adding the pressure at the casinghead between the tubing and the casing and the pressure due to the weight of the column of gas, but there is always possibility of error caused by fluid being in the annular space above the bottom of the tubing. If a well with tubing is flowing through either the annular space or the tubing, sufficient gas may be injected through the static space to insure that it is free of fluid but not sufficient to establish an appreciable friction loss. The pressure at the bottom of the tubing can then be calculated by adding to the pressure at the tubing head the pressure due to the weight of the column of gas. This is probably the most accurate method of calculating bottom-hole pressures. In wells flowing by gas-lift, the pressure at the point the gas enters the flow may be calculated by a gas-flow formula. Several types of pressure bombs have been used to measure the pressure at the bottom of wells. One is a piece of steel tubing with a check valve in the bottom and a connection for a pressure gage at the top. It is lowered into the well to the point at which the pressure is

Jan 1, 1931

By Frank E. Neil, O&apos

The formation tester, as the name implies, is a tool built for testing the contents of sands encountered in drilling Wells Without actually cementing casing on the sand. The tester was developed in the Mid-Continent and has been in use commercially there since about 1926. However, some two dozen patents have been issued on formation testers dating back to the seventies. The method apparently was an outgrowth of the old Mother Hubbard grain or bean packer, used around casing before the days of cementing casing. These packers were also seated in a tapered hole and if the formation tested was not satisfactory the casing was pulled loose and the hole taken down to another formation. A great deal of experimental work has been done in its development, and as a result of this work the formation tester became an accepted integral part of the petroleum development in California. The formation tester was introduced into California some three years ago by M. 0. Johnston. Months of discouraging and expensive work followed its introduction into this state, but one organization after another tried the tool and its use is now fairly general. Shortly after Johnston began testing in California, the Halliburton tester was also introduced into the state and now another tool is being introduced, the Shaffer-Roles tester. Principle and Operation of Testers The principle employed in all formation testers is that of packing off the fluid in the hole above the formation to be tested and thereby prevent,ing it from having access to the testing tool. This permits the fluid contained in the given formation to have unrestricted access to the tool. It is accomplished by running the tool and packer on the bottom of the drill pipe; the valves in the tool being closed while going into the hole to prevent fluid from entering the drill pipe. The packer is then seated at the desired point, trapping the drilling fluid above it. When this has been done, the valves in the tool are opened and the fluid from the formation is allowed to enter the empty pipe through the tool. If the

Jan 1, 1934

By A. R. Matthews

This description of the organization of the Consolidation Coal CO. is intended to include only the portion that is charged with the responsibility of the actual operation of an individual mine, although it has seemed advisable to include several of the all-division personnel, who necessarily come in direct contact with the mine officials. The Consolidation Coal Co. has a staff and line organization and, while most of the contact between these two wings is made between officers ranking above those discussed in this paper, field representatives of several of the staff departments play such an important role in the control of certain phases of activity at the mines that a true picture of the mine organization cannot be had unless these men are included. The demands made upon the producer of large quantities of coal have certainly never been so exacting as they are today. Reductions in the number of accidents and in the cost of individual accidents has passed from the category of a desirable achievement to an unqualified necessity. Although the market price of coal today is lower than it has been in many years, consumers have never been so critical of quality. This market condition is especially severe on the producer to whom one bad shipment may mean the loss of a contract. And the battle to keep the reduction of production costs abreast with constantly dropping prices wages incessantly. For the legitimate producer this situation demands a mine-operating organization that is comprehensive, versatile, efficient and economical; and it is in an attempt to meet these conditions that our present system has been designed. To say that this line-up is incapable of being improved or that it is applicable to all conditions would be to assume a degree of presumption which certainly is not intended here, but our system does meet the conditions which we are called upon to face today with a smoothness and thoroughness which we consider reasonably satisfactory. Authority or Consultation On the chart of Fig. 1 an attempt is made to show as clearly as possible the authority and responsibility of each mine official, together with the

Jan 1, 1931

By Howard Lee

I. GEOLOGY AND ORE OCCURRENCE IN central Colorado is a great belt of intrusive porphyry nearly 100 miles long (160 km.), extending from the Clear Creek district on the north to Aspen on the south, which includes many of the well known mining camps of the State. Near the southern end of this belt, at Leadville, the occurrence of these intrusives is most marked, resulting in intensive mineralization and the formation of a great variety of large orebodies. During the past 40 years, Leadville has been a steady producer of gold, silver, lead, zinc, manganese, iron, and bismuth, in the forms of sulfid, carbonate and oxide ores. It is the purpose of this paper to discuss pyrite alone, which, under present economic conditions, is valuable chiefly for its sulphur contents. The ore-bearing formation of the Leadville district consists of two beds of limestone separated by a layer of quartzite. The upper limestone is carbonaceous, and is known locally as the blue limestone. It varies in thickness from 50 to 300 ft. (15 to 91 m.). The lower limestone is Silurian, known locally as white limestone, and is about the same thickness as the upper bed. Underneath the Silurian limestone is a layer of Cambrian quartzite front 100 to 250 ft. (30 to 76 in.) thick resting on Archean granite, which forms the limit of ore deposition. As a rule, there is a sheet of white porphyry above the upper, or blue limestone; a sheet of gray porphyry is associated with the blue limestone, either in or below it, but the porphyries are not so regular as the quartzites and limestones and are not always found in their expected positions. Throughout the district there is an elaborate system of faults and intrusive porphyry dikes, which have all important bearing on ore deposits. The writer has seen two or three orebodies which were not closely associated with either a fault or a porphyry dike, but if the minor fractures and water courses are considered as part of the fault system it is safe to say that all orebodies are directly traceable to one or both of these causes.

Jan 8, 1918

By J. M. Morris

THE point to be made most clear in this paper is the economic value of flotation in the Benguet mill flow sheet. It is rather a statement of effect with no attempt at a technical explanation of the cause. Certain well-known, easily understood reagents, mechanisms and principles have been adapted to the conditions at Benguet, and have proved to be more successful than was demonstrated in the laboratory. The mechanical and metallurgical development of this particular operation was arrived at by trial and error, with fortunately very little error. Changes were slow, of necessity, which in the end proved a blessing in that time was afforded for observation and analysis of the disturbing factors; and as a result each change was a definite step towards higher efficiency. Many of these steps were unpredictable from labora-tory work because of the varied and differing characteristics of ores met with in daily operation of the mill, which were practically impossible to reproduce on a laboratory scale. The Benguet mill receives daily ores that differ as much as if they were delivered from three different properties. There is first the surface and upper-level zone, which produces an oxidized secondary ore contain-ing considerable iron oxide, manganese oxide and some organic matter. Formerly, most of this ore consisted of very soft fill with some hard rock mixed in. It also contained an unusual amount of iron and aluminum sulfate, which formed hydrates upon entering the alkaline cyanide solu-tion and caused excessive frothing. When flotation was introduced in the Benguet mill the general char-acteristics of this upper-level ore had changed considerably, in that it was practically all newly mined, fairly hard ore. It still contained many of the same disturbing elements, but was somewhat simpler to treat than formerly. The small proportion of fines is still troublesome in flotation, and plant practice probably does not show more than 80 per cent extraction on this small portion of the ore. No definite figure on this is available, as this particular ore is delivered at irregular intervals

Jan 1, 1936

By Fred Jones

The Cripple Creek district is in Teller County, Colo., about 18 miles in an air line west of Colorado Springs and at an elevation of 10,000 It. A line drawn through Colorado Springs and Pikes Peak will, if continued, about pass through the district. The character of the country generally is rolling, with few trees and little snow fall. The annual precipitation is about 20 in. All the water used by the mines is supplied by the Altman Water Co., which pumps from the west slope of Pikes Peak. Gold was discovered in 1891, since which time the district has produced $411,000,000. The peak of production was reached in 1900 and amounted to $25,000,000. At present the production amounts to about $400,000 per month. Geology In general, the geology of the district is simple; ash veins and dikes traverse a volcanic plug of breccia. The ore occurs as enriched spots along these dikes and veins. The dikes represent the most recent extrusions and consist of basalt and phonolite. (For a complete geological description reference is made to Professional Paper 54, 1906, of the U. S. Geological Survey.) The ore consists of small parallel seams of high grade. In only a few cases is the gold disseminated through the rock; much of the gold in the broken ore is found in the fines. The wall rock is hard blocky granite or breccia. About 25 per cent. of the rock mined is shipped as ore to the Golden Cycle mill at Colorado Springs. The height of an ore deposit is usually several times its length. Few flat oreshoots have been found. The veins are all steep and have a dip of 70 to 80°. Development The claims are all 300 by 1500 ft. and are held by location or patent. All mining is done through shafts, one of which has reached a depth of 2600 ft. The main working shafts are 41/29 by 1335 It. and are made up of three compartments, each 4 by 41/2 ft. in the clear. They are timbered with 10-in. Oregon posts and plates and 8-in. spreaders. Two compart-

Jan 1, 1925

By J. H. Bechtold, R. Kossowsky

1 HE superplastic behavior of the eutectoid A1-78 wt pct Zn alloy has been thoroughly investigated by Back-ofen et al.' The superplastic elongations and the marked resistance to necking were rationalized in terms of high strain rate sensitivity. In a subsequent paper2 superplastic behavior was formulated to show Nabarro-Herring diffusional creep as rate controlling at low strain rates, giving way to a dislocation climb process at higher strain rates. In a paper devoted to an interpretation of superplasticity in two-phase alloys, Packer and sherby3 have included the results of an examination of the structure of an Al-Zn eutectoid specimen before and after superplastic deformation. No significant change in grain size or directionality was observed in the deformed microstructures. This one observation led the authors3 to suggest that con- tinuous recrystallization or grain boundary migration was responsible for superplasticity. The purpose of this note is to report our observations on the superplastic behavior of the Al-Zn eutectoid alloy which differ in certain respects from works previously reported. Following Hayden et al., the results are discussed in terms of dislocation climb as the important factor during superplastic deformation. A heat of nominally high (99.995) purity 22 wt pct A1-78 wt pct Zn was induction-melted and cast into a 0.5 by 6 by 12 in. slab. The slab was heated to 350°C and rolled to 1/8-in.-thick plate. The plate was then cold-rolled to 0.040-in. thickness, annealed at 35OaC, and rolled to the final thickness of 0.020 in.* Speci-

Jan 1, 1969

Some Things We Don't Know about the Creep of Metals. By H. W. Gillett (T.P. 1087) Reduction of Iron Ores under Pressure by Hydrogen. By Michael Tenenbaum and T. L. Joseph (T.P. loll, with discussion) Induction Furnaces for Rotating Liquid Crucibles. By E. P. Barrett, W. F. Hol- bRook and C. E. Wood (T.P. 986, with discussion) Mechanism of Solidification and Segregation in a Low-carbon Rimming-steel Ingot,. By Anson Hayes and John Chipman (T.P. 988, with discussion) Solidification of Rimming-steel Ingots. By A. HultGRen and G. PhRagmen. (Contribution 112) Dendritic Structure of Some Alloy Steels. By Daniel .I. Martin and James L. Martin (T.P. 1066, with discussion) Occlusion and Evolution of Hydrogen by Pure Iron. By George A. Moore and Donald P. Smith (T.P. 1065, with discussion) Structure of Iron after Con~pression. Hy Charles S. Barrett (T.P. 977, with discussion) Structure of Iron after Drawing, Swaging, and Elongating in Tension. Ry Charles S. Barrett and L. H. LevensoN (T.P. 1038, with discussion) Magnetic Torque Studies of the Texture of Cold-rolled and of Recrystallized Iron-silicon Alloys. By Leo P. TaraSovJ(T.P. 1012, with discussion) Influence of Atmosphere and Pressure on Structure of Iron-carbon-silicon Alloys. By Alfred Boyles (T.P. 1046) Kinetics of the Decomposition of Austenite at Constant Temperature. By J. H. Austin and R. L. Rickett (T.P. 964, with discussion) Reaction Kinctics in Processes of Nucleation and Growth. By William A. Johnson and Robert F. Mehl (T.P. 1089, with discussion) Phase Changes in 3.5 Per Cent Nickel Steel in the Acl Region. By I. N. Bavarine (T.P. 1031, with discussion) Chromium in Structural Steel. By Walter Crafts (T.P. 1055) Surface Allotropic Transformation in Stainless Steel Induced by Polishing. By J. T. BuHwell and J. WUlff (T.P. 1032, with discussion) Nature of :Passivity in Stainless Steels and Other Alloys, I and 11. Ry H. H. Uhlig and John WUlff (T.P. 1050, with discussion) Thermal Expansion of Nickel-iron Alloys (Nickel from 30 to 70 Per Cent). Ry J. M. Lohr and Charles H. Hopkins (T.P. 987, with discussion) Low-temperature Transformation in Iron-nickel-cobalt Alloys. By L. L. Wy~Ian (T.P. 1013, with discussion) Fracture of Steels at Elevated Temperatures after Prolonged Loading. By R. H. Thielemann and E. R. Parker (T.P. 1034, with discussion)

Jan 1, 1939

Some Things We Don't Know about the Creep of Metals. By H. W. Gillett (T.P. 1087) Reduction of Iron Ores under Pressure by Hydrogen. By Michael Tenenbaum and T. L. Joseph (T.P. loll, with discussion) Induction Furnaces for Rotating Liquid Crucibles. By E. P. Barrett, W. F. Hol- bRook and C. E. Wood (T.P. 986, with discussion) Mechanism of Solidification and Segregation in a Low-carbon Rimming-steel Ingot,. By Anson Hayes and John Chipman (T.P. 988, with discussion) Solidification of Rimming-steel Ingots. By A. HultGRen and G. PhRagmen. (Contribution 112) Dendritic Structure of Some Alloy Steels. By Daniel .I. Martin and James L. Martin (T.P. 1066, with discussion) Occlusion and Evolution of Hydrogen by Pure Iron. By George A. Moore and Donald P. Smith (T.P. 1065, with discussion) Structure of Iron after Con~pression. Hy Charles S. Barrett (T.P. 977, with discussion) Structure of Iron after Drawing, Swaging, and Elongating in Tension. Ry Charles S. Barrett and L. H. LevensoN (T.P. 1038, with discussion) Magnetic Torque Studies of the Texture of Cold-rolled and of Recrystallized Iron-silicon Alloys. By Leo P. TaraSovJ(T.P. 1012, with discussion) Influence of Atmosphere and Pressure on Structure of Iron-carbon-silicon Alloys. By Alfred Boyles (T.P. 1046) Kinetics of the Decomposition of Austenite at Constant Temperature. By J. H. Austin and R. L. Rickett (T.P. 964, with discussion) Reaction Kinctics in Processes of Nucleation and Growth. By William A. Johnson and Robert F. Mehl (T.P. 1089, with discussion) Phase Changes in 3.5 Per Cent Nickel Steel in the Acl Region. By I. N. Bavarine (T.P. 1031, with discussion) Chromium in Structural Steel. By Walter Crafts (T.P. 1055) Surface Allotropic Transformation in Stainless Steel Induced by Polishing. By J. T. BuHwell and J. WUlff (T.P. 1032, with discussion) Nature of :Passivity in Stainless Steels and Other Alloys, I and 11. Ry H. H. Uhlig and John WUlff (T.P. 1050, with discussion) Thermal Expansion of Nickel-iron Alloys (Nickel from 30 to 70 Per Cent). Ry J. M. Lohr and Charles H. Hopkins (T.P. 987, with discussion) Low-temperature Transformation in Iron-nickel-cobalt Alloys. By L. L. Wy~Ian (T.P. 1013, with discussion) Fracture of Steels at Elevated Temperatures after Prolonged Loading. By R. H. Thielemann and E. R. Parker (T.P. 1034, with discussion)

Jan 1, 1939

By Frank A. Linforth

The object of this paper is to present a brief outline of the methods of geologic mapping employed in the Geological Department of the Anaconda Copper Mining Co., at Butte, and to show by means of a few typical examples the practical nature of the results obtained. The extremely complicated geological conditions early encountered in Butte mining led mine operators to realize the necessity of accurate detailed geologic mapping m an aid to successful development of the ore bodies. The organization of the Anaconda Geological Department was undertaken in 1900 by H. V. Winchell, who, in conjunction with D. W. Brunton, worked out the essential methods of procedure which are, in the main, followed at the present time. Since the year 1906 the geologic work has been under the direction of Reno H. Sales, and in some respects the scope of the work has been slightly enlarged. An excellent article describing the general equipment of the geological department was presented by D. W. Brunton at the British Columbia meeting of the Institute in 1905.' His idea, that data collected underground and recorded should be put to practical use and not remain a mere " inventory of the company's underground possessions," is the keynote to the success of applied geology in Butte. The geologic notes are taken as soon as possible after the ground is broken so that any mistake in the mining may be corrected at once, or any particularly advantageous procedure may be suggested before any useless work is done. Taking the notes underground is a comparatively simple matter, but a few necessary precautions may be pointed out. The essential to success is that the notes shall show exactly what geological facts are disclosed. The observer must discriminate carefully between important and unimportant exposures in making the record, especially as regards the relation between veins and stringers, between faults and minor slips, or between the characteristics of veins of different ages. A simple color scheme has been adopted for making this record. Red pencils are used to indicate

Jan 1, 1914

By Emory Kemler

The problem of determining the most desirable operating conditions of an oil-well pumping unit, the selection of the proper material and size of sucker rods, and the design of the pumping unit, requires that the sucker-rod loads be known with a reasonable degree of accuracy. In production practice, it is also desirable to know the effects of operating speeds and strokes on a plunger motion, as well as on the rod loads. For a particular well, data on rod loads can be obtained by measuring the load in sucker rods with a dynamometer. This method is not satisfactory because it does not permit the various factors to be investigated independently. It is also impossible to measure the plunger motion simultancously with rod motion under operating conditions. The mathematical solution is impractical because of the simplifications that have to be made to get a solution and the tremendous amount of numerical work that is necessary after such a simplified solution has been attained. This paper shows how analogies and models can be applied to the solution of these problems. The loads set up in a sucker-rod string during the ordinary pumping cycle are made up of the weight of the rods, force required to accelerate the rods, weight of the oil and force required to accelerate the oil on the upstroke, rod friction, stuffing-box friction, plunger friction, friction of the oil in the tubing and rods, arid friction loss through the valves. The problem of determining the sucker-rod load is further complicated by the fact that the long oil column and the sucker-rod column act as springs, which affect the transmission of the polished-rod motion. A further complication is the fact that the motion cannot be transmitted at a speed greater than that of the velocity of sound in the material, and this means that there will be a time lag in the transmission in the motion, as well as a modification of its magnitude and a phase displacement.

Jan 1, 1936

By R. R. Hawkins

PEoperly designed tubing strings make it possible to continue the flowing life of wells beyond the stage where ordinarily they would be put to pumping. Wells no longer able to flow through 2-in. tubing can be made to produce through smaller tubing if conditions within the well are carefully studied and correctly designed strings are installed. In this way, pumping expense may be postponed and in some pools it is within reason that the entire recovery may be obtained by natural flow if maintenance of pressure is practiced. Infrequent tubing changes would be necessary but their cost would be much less than that of installing and maintaining pumping equipment. If small wells are to be made to flow naturally, careful consideration must be given the actual lifting mechanics within the string, so that fairly accurate knowledge of reservoir conditions, especially pressure, is essential. Wells producing between 5 and 25 bbl. daily are classified here as "small wells." Exponential Flow A maximum of the energy contained in the expanding gas must be employed to do useful work if natural flow is to be continued. It is evident that adiabatic expansion would defeat this purpose, therefore the velocity of the gas must be held down to a minimum in order that isothermal expansion may be approached. Of course, true isothermal expansion would not be obtainable in an oil well, hence the use of the term "exponential." 1 Obviously the closer the approach to isothermal expansion, the more efficient the lift. Experiments by the U. 8. Bureau of Mines² have shown that for isothermal expansion to take place in a gas well where water is being produced, a definite relationship exists between the depth of the well and the minimum operating pressure. The latter must be such that the tubing fill-up, if static conditions prevailed, would be equivalent to 14 per cent of the distance between the top of the fluid inside the tubing and the tubing head. It has been observed that variations in this essential ratio

Jan 1, 1932

Future of State and Federal Oil Regulation. BY NORTHCUTT ELY (Trans , vol 118 2400 words) The Interstate Oil Compact, ratified by six states and Congress in 1935, replaced the petroleum code, invalidated with other codes by the Schechter decision This compact endeavors, first, to conserve reservoir energy of oil pools through substantially uniform conservation measures by the states, second, it recognizes the state rather than the Federal Government as possessing the necessary police power for that purpose, third, it establishes an interstate advisory commission, so that orderly production in one state is not penalized by uncontrolled production in another, fourth, Federal interests are recognized in the control of hot oil, regulation of imports and fact-finding forecasts of supply and demand by the Bureau of Mmes It is not as complete an instrument as proposed by the Federal Oil Conservation Board in 1932, but is workable, and will be effective in proportion to the support given it by the industry Three results may follow First, now that fear of Federal control has subsided, the industry may lose interest in the compact and let it fall to pieces, second, if vigorously supported by the industry, the compact can accomplish most of the conservation objectives sought by the Federal control measures now believed unconstitutional, third, if the Compact fails, Federal regulation is almost certain to be revived, and can probably be sustained in connection with neutrality legislation, regulation of interstate pipe lines, and coordination of Federal and state gasoline taxes Nearly every step toward governmental regulation has originated within the industry state proration, the Federal petroleum code, Federal control of imports, Federal control of hot oil are examples The Compact shows a trend toward coordination between the powers of the industry, the state government, and the Federal Government If this arrangement fails through lack of interest by the oil industry, the next step is likely to be absorption by the Federal Government of the other two factors involved in the situation

Jan 1, 1937

By Emory Kemler

The problem of determining the most desirable operating conditions of an oil-well pumping unit, the selection of the proper material and size of sucker rods, and the design of the pumping unit, requires that the sucker-rod loads be known with a reasonable degree of accuracy. In production practice, it is also desirable to know the effects of operating speeds and strokes on a plunger motion, as well as on the rod loads. For a particular well, data on rod loads can be obtained by measuring the load in sucker rods with a dynamometer. This method is not satisfactory because it does not permit the various factors to be investigated independently. It is also impossible to measure the plunger motion simultancously with rod motion under operating conditions. The mathematical solution is impractical because of the simplifications that have to be made to get a solution and the tremendous amount of numerical work that is necessary after such a simplified solution has been attained. This paper shows how analogies and models can be applied to the solution of these problems. The loads set up in a sucker-rod string during the ordinary pumping cycle are made up of the weight of the rods, force required to accelerate the rods, weight of the oil and force required to accelerate the oil on the upstroke, rod friction, stuffing-box friction, plunger friction, friction of the oil in the tubing and rods, arid friction loss through the valves. The problem of determining the sucker-rod load is further complicated by the fact that the long oil column and the sucker-rod column act as springs, which affect the transmission of the polished-rod motion. A further complication is the fact that the motion cannot be transmitted at a speed greater than that of the velocity of sound in the material, and this means that there will be a time lag in the transmission in the motion, as well as a modification of its magnitude and a phase displacement.

Jan 1, 1936

By James D. Sisler

Among the various studies made by the Coal Fact Finding Commission, appointed by President Warren G. Harding in 1922 to investigate all phases of the coal-mining industry in the United States and to report to Congress, was one concerning the amount and nature of losses in mining bituminous coal in the eastern part of the United States. This study was carried on under the direction of the U. S. Bureau of Mines. The writer was appointed field engineer to investigate the problem in Ohio, Pennsylvania and West Virginia. Some 400 mines were studied in these three states and conclusions were drawn from many sources of data. The summary report written by George S. Rice and J. W. Paul states that "the field reports indicate that the recovery in Ohio will remain about as at present, except in the Belmont district; whereas in Pennsylvania it will gradually improve, and in West Virginia it will improve rapidly." Since 1922, the writer has been interested in gathering material to substantiate or contradict these prophecies. Nature of Coal Losses There are six general causes of losses of coal in mining: (1) coal left on the roof and bottom; (2) coal lost in room, entry and panel pillars; (3) coal lost in oil-well or gas-well pillars; (4) coal lost under buildings, railroads and boundaries; (5) coal lost in handling and prepayation, underground and surface; (6) coal lost by rolls, thin or dirty areas and under streams. Local economic aspects that dominate the type of mining conditions determine to some extent whether certain losses are avoidable or unavoidable. In general, however, unavoidable losses include coal lost in the protection of buildings, streams, railroads, restricted properties and around oil and gas wells. Barrier pillars and other safety pillars are unavoidable losses as long as their size does not exceed the minimum for adequate safety. Natural physical conditions beyond human control, such as rock faults, clay veins, partings and binders, bad top and bottom, rolls and horsebacks, cause unavoidable losses. Unavoidable losses

Jan 1, 1931

By Barry N. Whittaker

INTRODUCTION Considerable progress has been achieved with long- wall mining in recent years especially in enabling increased rates and levels of output to be gained, higher standards of safety and increased usage of advanced technological developments. Longwall mining also has major long term advantages, prominent amongst which is general minimisation of the effects of pillars and room intersections giving rise to future instability problems as can be the case with room and pillar mining operations. The fact that longwall mining is not presently limited by depth below surface inclination of seams or thickness of seam to be worked strengthens its position as the most popular underground mining method for extracting coal seams in Europe. Its wider application in North America and Australia can give rise to significant economic benefits coupled with higher levels of safety and recovery of coal. This present paper reviews recent progress achieved and draws attention to the more important factors influencing longwall mine design and layout. LONGWALL STRATA PRESSURE ABUTMENTS A longwall gives rise to major redistribution of strata pressures. The roof behind a longwall is normally allowed to cave and permit subsidence of the overlying strata and eventually giving rise to a trough depression at the surface. Consequently, reestablishment of strata loading within the caved region behind the longwall depends upon effective caving and subsequent recompaction. This requires sufficient depth pressure and/or adequate width of extraction in relation to the depth to achieve breaking of overlying roof beds necessary to reload the extracted region. Figure 1 shows results of an analysis carried out by Whittaker and Singh (1979) indicating the pattern of redistribution of vertical stress around a longwall in the plane of the seam. The analysis represents the average depth of longwall working in the UK, and was performed using a stress balance assumption of compatibility before and after mining. The main stress abutments are indicated by (1) the front abutment strata pressure zone which travels with the longwall, and (2) the flank abutment strata pressure zone which

Jan 1, 1982

By R. M. Hudson

A study has been made of the decarburization of low-carbon sheet steels at temperatures from 1100" to 1475°F in mixtures containing hydrogen, nitrogen, water vapor, and in some instances carbon monoxide. Decarburization occurs principally by the reaction C (in steel) + H20 = CO + H2 and follows a first-order rate law. The decarburization rate appreciably increases with an increase in temperature up to about 1325°F, but the increase in rate is small with fur- Use of a dry hydrogen atmosphere results in a relatively slow decarburization of steel and use of a wet hydrogen atmosphere results in relatively rapid decarburization. It is now generally recognized' that the reaction C (in steel) + H2O = H2 + CO [l] accounts for most of the decarburization that occurs in wet hydrogen-containing atmospheres. The present article is concerned with the decarburization of low-carbon sheet steel in H2-N2 atmospheres ther increase in temperature. The limiting rate of decarburization can be predicted from a knowledge of the solid solubility and diffusivity of carbon and this rate is approached as the water-vapor content of an atmosphere is increased. Hydrogen contents above about 8 pct are beneficial only in that they permit higher levels of water vapor to be used without oxidation of the steel. A buildup of CO in the atmosphere lowers the rate of decarburization. containing various amounts of water vapor and carbon monoxide. The effectiveness of these atmospheres and the influence of temperature on decarburization rate will be considered. EXPERIMENTAL WORK The chemical compositions of the three steels used in decarburization-rate studies are listed in Table I. Steel A was a commercially hot-rolled rimmed steel that was cold-reduced at the Laboratory to furnish specimens 0.025, 0.041, and 0.059 in. thick. Most of the experiments in which this steel was used were made on the 0.041-in.-thick material. Steel B and Steel C were cut from 0.010-in.-thick commercially cold-reduced coils that were

Jan 1, 1963

By Frank Linforth

THE object of this paper is to present a brief outline of the methods of geologic mapping employed in the Geological Department of the Anaconda Copper Mining Co., at Butte, and to show by means of a few typical examples the practical nature of the results obtained. The extremely complicated geological conditions early encountered in Butte mining led mine operators to realize the necessity of accurate detailed geologic mapping as an aid to successful development of the ore bodies. The organization of the Anaconda Geological Department was undertaken in 1900 by H. V. Winchell, who, in conjunction with D. W. Brunton, worked out the essential methods of procedure which are, in the main, followed at the present time. Since the year 1906 the geologic work has been under the direction of Reno H. Sales, and in some respects the scope of the work has been slightly enlarged. Au excellent article describing the general equipment of the geological department was presented by D. W. Brunton at the British Columbia meeting of the Institute in 1905.1 His idea, that data collected underground and recorded should be put to practical use and not remain a mere " inventory of the company's underground possessions," is the keynote to the success of applied geology in Butte. The geologic notes are taken as soon as possible after the ground is broken so that any mistake in the mining may be corrected at once, or any particularly advantageous procedure may be suggested before any useless work is done. Taking the notes underground is a comparatively simple matter, but a few necessary precautions may be pointed out. The essential to success is that the notes shall show exactly what geological facts are disclosed. The observer must discriminate carefully between important and unimportant exposures in making the record, especially as regards the relation between veins and stringers, between faults and minor slips, or between the characteristics of veins of different ages. A simple color scheme has been adopted for making this record: Red pencils are used to indicate.

Jan 11, 1913