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Mining Methods JAY A. CARPENTER, Chairman CLYDE E. WEED, Vice-Chairman ROY A. HARDY, Secretary Alluvial Mining CLINTON BERNARD O. B. PERRY NORMAN CLEAVELAND C. M. ROMANOWITZ R. B. EARLING J. B. STAPLER BENERE H. GRANT CHARLES THURMAN Open-Cut Mining Iron G. E. DIEHL EARL E. HUNNER P. G. HARRISON G. E. LEVEQUE Copper LOUIS BUCHMAN W. H. GOODRICH J. H. DAVIS WALTER S. LARSH

Jan 1, 1941

By W. B. Morrison

The principal factors influencing the total percent elongation of a lead-tin eutectic and several low-alloy steels which exhibit superplasticity were investigated. These factors are: a) Strain-rate sensitivity of the stress (m). b) Specimen geometry; in particular, diameter-to-length ratio (d0/l0), and surface irregularity (e.g. notches). A feature of the tensile deformation of a superplastic alloy is the early appearance of a neck which continues to extend throughout the test. As a result the total elongation is directly related to the diameter-to-gage-length ratio. The strain-rate sensitivity of the stress varies during extension, mainly because of microstruc-tural changes. A satisfactory correlation exists between the minimum strain-rate sensitivity and total elongation, as indicated in the equation shown below. Notches cause a considerable reduction in total elongation and their effect is greatest at high values of strain-rate sensitivity. An initial notch depth exists below which there is no appreciable effect on elongation. An equation relating elongation to strain-rate sensitivity and specimen geometry is proposed, THE total percent elongation of a tensile specimen is usually regarded as a measure of superplasticity. However, little attention has been given to the fact that total elongation is also a function of specimen diameter and gage length, even though the importance of geometry has long been recognized in the tensile testing of materials in which elongations are relatively small.* In the present study, the effect on superplas- tic extension of the ratio of specimen diameter to length was investigated and an analysis was made of strain distribution along the gage length. Superplastic alloys are characterized by having a flow stress sensitive to strain rate but relatively insensitive to strain.2"' In an earlier study,5 it was found that the strain-rate sensitivity of several low-alloy steels changed during the test and that the minimum value correlated best with total elongation. In the present study, the variation of strain-rate sensitivity during the straining of a lead-tin alloy was investigated. EXPERIMENTAL PROCEDURE Lead-tin eutectic alloy (32 pct Pb 68 pct Sn), made from high-purity lead and tin, was cast in the form of 1-in. diam rod. The rod was cold-rolled in stages to 0.25 in. diam and then swaged to 0.125 in. diam. Samples were cut from the rod at various stages of the mechanical working process. Tensile test specimens were then made by attaching threaded steel ends to the rods by an epoxy-base thermosetting adhesive which required a setting treatment of 2 days at room temperature. The rods were seated in the steel ends in holes approximately 0.01 in. oversize. The test pieces thus made were of various diameters and gage lengths. These were stored at a temperature of about -70°C (-94°F) until required for testing. The distribution of strain along the gage length of a specimen was determined at various stages of the tensile test. The lead-tin alloy was superplastic at room temperature and direct observations during testing were simple. The gage length was divided by reference marks into five initially equal units. These reference marks were made with ink and were reinforced during the test when the initial marks became faint. Photographs were taken, at intervals, of the deforming specimen and measurements of the elongation in each of the gage units were made on these photographs. Tests were also done on several superplastic low-alloy steels whose properties were described earlier.5 The chemical compositions of these steels are given in Table I. A diagram of the notched tensile specimen used in the steel tests is shown in Fig. 1. The specimens were tested at 900°C (1650°F) in a furnace through which a mixture of He + 2 pct H was continuously circulated.5 RESULTS Strain Distribution. Approximately 20 tests on lead-tin alloy specimens were conducted to determine the strain distribution during the test. An example is shown in Fig. 2 of the strain distribution in the gage

Jan 1, 1969

TULSA SECTION At the smoker concluding the two day meeting of the Tulsa section of the American Institute of Mining and Metallurgical Engineers, Tulsa, Okla., Feb. 26, 1919, Dr. Willis T. Lee, the new head of the Geological Department of the University of Oklahoma, was introduced to the assembled geologists and mining engineers. Dr. Lee requested that the geologists and engineers who were making a specialty of petroleum geology assist him in giving a good course in practical oil geology in the Geological Department of the University. After a motion offering the services of all present in giving lectures on their special subjects had been adopted, Dr. Perrine of Hutchinson, Kans., named the geologists who were pledged to give lectures in Dr. Lee's course. The students in geology at Norman are assured of the latest information regarding practical work in petroleum geology and will have the inspiration derived from contact with men who are actually at work upon the problems which they are studying. Dr. Lee and President Brooks of the University are to be congratulated upon the introduction of this .method of instruction. The plan thus put into operation is similar to the graduate system of coaching in athletics followed at many of the large universities; what is good for instruction in athletics should also prove good for instruction in applied geology.

Jan 6, 1919

By Johnson Crawford, Alan H. Hoagland

Zinc mining at Jefferson City began in 1854 with small scale production of oxidized ore from open pits. Significant production began in 1913 with the development of the Mascot Mine by the American Zinc Company. In 1965, four flotation mills were treating crude ore at the rate of about 12,000 tons per day and the Mascot-Jefferson City district currently is the largest zinc producing area in the United States. The producing mines, Mascot, Young, North Friends Station, New Market Zinc, Grasselli, Davis-Bible, Coy, and the Jefferson City, are 15 to 28 miles northeast of Knoxville in the Valley and Ridge physiographic province, an area of gentle relief lying between the more rugged Great Smoky Mountains and the Cumberland escarpment. The ore is strata bound, occurring essentially within a stratigraphic range of 200 feet in the Lower Kingsport and Upper Longview formations of Lower Ordovician age. In the lower strata of the mineralized section, the ore generally is found in coarsely crystalline elastic dolomite breccia containing silica and chert debris within a sequence of aphanitic limestones. The upper strata of the mineralized section are fine-grained primary dolomites that, in the ore zones, have been fragmented in mosaic patterns by solution collapse with the interfragmental space filled by white gangue dolomite and sphalerite. The mineralogy is unusually simple, sphalerite being the only important sulfide. Pyrite is very sparse. Dolomite gangue is abundant, silica was deposited in quite small amounts, calcite is minor, and fluorite and barite are very rare. The principal ore controlling structures are rubble breccia zones that were formed during the post-Lower Ordovician-pre-Middle Ordovician erosion interval by supergene solution as a phase of the development of a regional karst system of underground drainage that extended to' depths of at least 800 feet. The major Appalachian orogenic structures are post-ore and have been superimposed on the ore bodies. There is substantial evidence to support the current thinking of the writers that the ore deposits were formed at a depth not exc1~eding 800 feet.

Jan 1, 1968

By W. G. Sinclair

THE North Texas district presented in this paper includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Jack, Knox, Montague, Wichita, Wilbarger and Young. It corresponds with the Texas Railroad Commission's district No. 9. Table I conforms with the nomenclature of pools as designated by the Commission. Most of the oil and gas produced in this region, generally referred to as the Red River uplift, comes from the Pennsylvanian strata. In recent years, however, increasing amounts are being developed in both the Mississippian and Ordovician.

Jan 1, 1946

By W. G. Sinclair

The wartime momentum of exploration continued throughout the year 1945 despite the end of hostilities in mid-August. The table below illustrates drilling activity in the various categories: Completed wells. . . . . . . . . . . . . . . . . . . . . . . . 401 Wildcats.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104 Wildcat discoveries, oil.. . . . . . . . . . . . . . . . . . . 2 Wildcat discoveries, gas-condensate.. . . . . . . 4 Development wells.. . . . . . . . . . . . . . . . . . . . . .297

Jan 1, 1946

By Mark C. Malamphy

AT present the Federal Government represents the only organization applying geophysical methods of prospecting in Brazil. The geophysical work of the National Department of Mineral Production, which will be described in the following pages, must be considered as a program of experimental work designed to demonstrate the applicability of the more or less "standard" methods of geophysical prospecting to various problems of economic interest in Brazil by means of practical examples of results obtained in certain typical areas. Our work is somewhat similar to that of the Imperial Geophysical Experimental Survey of Australia, but our task has been greatly simplified by the ever increasing number of technical publications relative to the theory of instruments and methods.

Jan 1, 1936

By H. G. Doll

'This paper discusses a method and apparatus for determining the dip of formations traversed by a drill hole, by means of electrical measurements in the hole. The process consists in recording the Spontaneous Potentials present along three oriented generatrices in the hole. By comparison of the three curves thus obtained, after application of a correction factor to compensate for any deviations of the hole, the dip angle and the dip direction are determined. Excellent accuracy is obtained for dip angles over 10°. Because the method is simp1e and the apparatus rugged, the measurements are rapid and reliable; consequently, they can be made at all the levels that are of interest at any time after the well has been drilled. Mechanical cores are not needed to evaluate the dips. A convenient, time-saving procedure is to perform the dipmeter survey at the time the electrical log is taken, using for both operations the same cable and truck. Actual examples of results obtained in wells of the Gulf Coast area are given. Introduction The problem of determining the angle and direction of the dip of the strata traversed by a drill hole has practical interest, and sometimes vital importance, which need not be emphasized to the oil industry. The need for that type of information has existed ever since wells have been drilled. Certainly it has not subsided, in spite of the numerous inventions and improvements made in other fields of the art of drill-hole exploration. The few examples given in this paper are but illustrative of this fact. In the past, methods have been devised, and used, to solve this problem, but generally they have met with limited success, possibly because they failed more or less to answer the requirements of a modern age for fast yet accurate measurements. If accurate, the results were obtained at the cost of very tedious and lengthy operations. The new S. P.* dipmeter service offered to the oil industry is the result of exhaustive and in this particular field. In 1032 a dipmeter and electromagnetic teleclinom-eter service was made available. The apparatus employed then was of a rather delicate and costly construction, and the measurements had to be made with precautions sometimes difficult to secure on the rig. Although the information given by the electromagnetic dipmeter was limited to the direction of the dip, very interesting results were obtained in California, Trinidad, Venezuela, Rumania and, most notably, in the Netherlands East Indies.+ Apparatus The S. P. dipmeter surveys present none of the drawbacks mentioned above. The apparatus is rugged and free from constructional complications, therefore well adapted to field use. This, combined with the new, basically simple approach to the problem, explains the rapidity of execution of the measurements. The results are remarkably accurate and they are complete, giving the

Jan 1, 1946

By H. G. Doll

'This paper discusses a method and apparatus for determining the dip of formations traversed by a drill hole, by means of electrical measurements in the hole. The process consists in recording the Spontaneous Potentials present along three oriented generatrices in the hole. By comparison of the three curves thus obtained, after application of a correction factor to compensate for any deviations of the hole, the dip angle and the dip direction are determined. Excellent accuracy is obtained for dip angles over 10°. Because the method is simp1e and the apparatus rugged, the measurements are rapid and reliable; consequently, they can be made at all the levels that are of interest at any time after the well has been drilled. Mechanical cores are not needed to evaluate the dips. A convenient, time-saving procedure is to perform the dipmeter survey at the time the electrical log is taken, using for both operations the same cable and truck. Actual examples of results obtained in wells of the Gulf Coast area are given. Introduction The problem of determining the angle and direction of the dip of the strata traversed by a drill hole has practical interest, and sometimes vital importance, which need not be emphasized to the oil industry. The need for that type of information has existed ever since wells have been drilled. Certainly it has not subsided, in spite of the numerous inventions and improvements made in other fields of the art of drill-hole exploration. The few examples given in this paper are but illustrative of this fact. In the past, methods have been devised, and used, to solve this problem, but generally they have met with limited success, possibly because they failed more or less to answer the requirements of a modern age for fast yet accurate measurements. If accurate, the results were obtained at the cost of very tedious and lengthy operations. The new S. P.* dipmeter service offered to the oil industry is the result of exhaustive and in this particular field. In 1032 a dipmeter and electromagnetic teleclinom-eter service was made available. The apparatus employed then was of a rather delicate and costly construction, and the measurements had to be made with precautions sometimes difficult to secure on the rig. Although the information given by the electromagnetic dipmeter was limited to the direction of the dip, very interesting results were obtained in California, Trinidad, Venezuela, Rumania and, most notably, in the Netherlands East Indies.+ Apparatus The S. P. dipmeter surveys present none of the drawbacks mentioned above. The apparatus is rugged and free from constructional complications, therefore well adapted to field use. This, combined with the new, basically simple approach to the problem, explains the rapidity of execution of the measurements. The results are remarkably accurate and they are complete, giving the

Jan 1, 1946

By Harold Vagtborg

Equilibrium vaporization ratios were obtained for light hydrocarbons, nitrogen, carbon dioxide, and hydrogen sulfide in a reservoir fluid containing 35 mole per cent hydrogen sulfide. The data cover the range from 700 to 2500 psia at 154°F. The results of this study are compared with results obtained by other investigators on systems containing less hydrogen sulfide. When large amounts of hydrogen sulfide are present, the equilibrium vaporization ratios for ethane and heavier hydrocarbons are greater than the ratios for systems containing little or no hydrogen sulfide. Large amounts of hydrogen sulfide have the reverse effect on the ratios for methane. Routine PVT studies were performed on the reservoir fluid including flash and differential liberations of the dissolved gas. The pressure-volume relationships of the saturated fluid were also determined. It is shown that the use of published correlations on physical properties of reservoir .fluids can lead to gross errors when applied to systems containing large amounts of hydrogen sulfide. INTRODUCTION Equilibrium vaporization ratios for various components in naturally occurring crude oil and condensate systems have been reported in the literature.1,2,3,4 Recently, several papers have been published with emphasis on non-hydrocarbon components such as nitro- gen, carbon dioxide and hydrogen sulfide.5,6,7,8,9 The increased discovery of reservoir fluids having high concentrations of these non-hydrocarbon components, particularly hydrogen sulfide, has created a need for a further study of their phase behavior. Equilibrium vaporization ratios are known to vary with pressure, temperature, and overall composition of the system.'" It was anticipated that ratios for systems containing large amounts of hydrogen sulfide would differ from the ratios for systems containing small amounts of hydrogen sulfide. Therefore, the present work was undertaken in order to obtain reliable equilibrium vaporization ratios for the reservoir-fluid in question. PROCEDURE The procedure followed was evolved after considerable experimentation on methods of handling the very sour crude. It was found that drying agents (e.g. CaCl2 and CaSO4) absorbed an appreciable amount of hydrogen sulfide from the gas used to prepare the recombined samples. The concentration of hydrogen sulfide dropped as much as 10 mole per cent in a single pass through a 3-ft drying tube. It was also found that when undried gas was agitated with mercury in the PVT cell, a black scum, believed to be mercuric sulfide, was formed and the hydrogen sulfide content of the gas dropped several mole per cent. Because composition changes during a run could not be tolerated, separation of the mercury and sour fluid was necessary. In order to effect this separation, a stainless steel piston, equipped with Teflon O-rings, was placed in the PVT cell between the mercury and the sour fluid. This piston had to be constructed in three parts because

Jan 1, 1955

By AIME AIME

HIS many admirers regard the "official"' candidate for president of the Institute in 1934 as far above the average in ability and capacity; but perhaps his outstanding characteristic is dependability. Some men of great brilliance succeed indifferently because they cannot be relied upon. When Howard Nichols Eavenson undertakes to do something he either does it, or he proves to his own satisfaction that the particular object is not attainable. And the latter outcome is exceptional because his judgment is so good that he generally foresees the impossibility and selects in advance a practical alternative. Though a tireless worker he is pretty sure that his energy is not spent futilely.

Jan 1, 1933

By Kirtley F. Mather

FROM almost every point of view, petroleum was "strategic mineral number one" during the World War that ended in 1945. Even the spectacular advent of the atomic bomb in the final days of the conflict did not displace it from its position of prime importance, although within a few years uranium will almost certainly be the "number one" material in the minds of military strategists, if it is not even now in that position. But both as fuel and as raw material for chemical industries, petroleum will hold the center of the stage for many years to come. Hardly any other substance illustrates so fully the manner in which science and technology may be combined to achieve the utmost success in contributing to human efficiency and comfort. Fundamental to any understanding of the problems implied by my topic

Jan 1, 1948

By C. L. Clark

EVERY user of steel should ask himself whether or not he is taking full advantage of the discoveries of the steel metallurgists during the last few years, or is merely buying grades that looked to be the best five or ten years ago for various specific purposes and have since proved perfectly satisfactory in his plant. If he has not kept abreast of the times, then it is probable that something better has been developed, or something just as good that costs less. Though this article will have to do with steel for high-temperature applications primarily, marked advances have been made in steels for other purposes as well.

Jan 1, 1940

By JAMES GAYLE

(Presented at the Washington meeting, May 3, 1905, and simultaneously sent to the Iron and Steel Institute, for presentation at the meeting of that Society in London, May 11, 1905.) IT is to be regretted that the data respecting the use of dry-air blast, which was presented to the Iron and Steel Institute at its meeting in the United States, in October, 1904, should. have been restricted to the period from August 25th to September 9th inclusive, and from September 17th to 30th inclusive. In order to present the paper at all it was found necessary to limit the record of operations to the period above stated. In the discussion of the paper it would appear from the conclusions of some participating therein, that they have been placed at some disadvantage in considering the economies obtained through the use of dry-air blast, by reason of the data covering such a short period. It is the purpose of this communication to present in detail the record of operations of the Isabella Furnaces from November, 1904, to March, 1905, inclusive, as shown by the furnace-records. The month of October, 1904, is not included, as the furnace using dry-air blast was stopped several times for repairs, and while the record was a very good one considering these interruptions, yet it was not a continuous one. The record for Furnace No. 1 using dry-air blast, and the comparison with Furnace No. 3 using natural air for the month of November, 1904, is set forth in Table I. By a reference to my former paper it will be noted that the month of November is the beginning in this country of the winter period, when the atmosphere decreases rapidly in humidity. The month of October being the transition month in the autumn and April in the spring, and furnaces using natural air approach more closely, from November on, to the conditions obtained by the use of dry-air blast. The data given in

Jul 1, 1905

By W. H. Herrnstein, F. H. Beck, M. G. Fontana

Sulfur solubility in a iron was measured in the 750 to 890°C temperature range and was found to be insensitive to ferrite purity within a limited composition range. The permeability of sulfur in ferrite was determined from the internal sulfidation of Fe-Mn alloys. From the solubility and permeability results, the diffusivity of sulfur in ferrite could be calculated. These results are summarized as follows: Dissolved sulfur decreased the lattice parameter of ferrite. The effect of dissolved sulfur on the tensile properties of ferrite at low temperatures was also determined. SINCE sulfur is an important residual impurity in commercial irons and steels, effects associated with the presence of sulfur as a solute in iron are of considerable practical interest. Unfortunately, certain basic information relative to the Fe-S system appears to be lacking in the literature, e.g., the effect of dissolved sulfur on the lattice parameter and mechanical properties of ferrite. In addition, discrepancies exist in previously reported results for the solubility of sulfur in ferrite. These discrepancies raise questions regarding the sensitivity of sulfur solubility to the purity and microstructure of iron. This study was undertaken primarily in an effort to obtain reliable data on the solubility of sulfur in ferrite. Additional objectives included determination of the permeability and diffusivity of sulfur in ferrite by the internal sulfidation method and determination of the effect of dissolved sulfur on the lattice parameter and tensile properties of ferrite. EXPERIMENTAL METHOD Three grades of iron, encompassing a range of impurity levels, were employed in the study. The grades were designated VME (vacuum-melted electrolytic), SPZR (single-pass zone-refined), and MPZR (multipass zone-refined). The composition of each grade is given in Table I. Poly crystalline and single-crystal strip specimens were employed in the solubility experiments. Uniform grain size strip (ASTM 3 to 5) of 0.005 to 0.020 in. thickness was obtained by alternate cold reductions of 60 thickness 60 to 80 pct and recrystallization at 650°C for i hr in pure, dry argon. Single-crystal specimens were produced in 0.010-in.-thick SPZR iron strip by the strain-gradient anneal technique. Recrystallized strip 0.25 in. wide was strained until a Luders band or bands had propagated over the length of the strip; the strip was then annealed by drawing it through a 150°C per in. gradient (890°C peak temperature) at 1 in. per hr in an atmosphere of pure, dry argon. Laue photographs of the crystals produced exhibited no discernible asterism. Specimens were equilibrated with H-H, atmospheres at temperatures between 750" and 890" by one of two methods, each of which makes use of the reaction: The encapsulation sulfurization method was employed in the majority of the solubility experiments. A strip

Jan 1, 1969

By John D. Sullivan

MAJOR technical advances seldom occur in a single year, and this is especially true with aluminum and magnesium where marked improvements in metallurgical processes and products took place during the war years. Nevertheless, the light metals and alloys, particularly aluminum, are advancing in commercial importance and are finding their niche in industry. New applications during the year have resulted from a better over-all knowledge of properties, handling, etc., rather than from revolutionary new developments.

Jan 1, 1948

By L. A. Creglow

IN common with many other companies engaged in the mining and processing of ores, research has always been an important activity of the United States Smelting Refining and Mining Company. Much of this research has been carried on at the various plants of the Company by the operating staffs, and over the years has been an essential factor in developing new methods and improving existing methods of operation. In 1917 arrangements were made with the Massachusetts Institute of Technology under which the Company had the exclusive use of one or two small laboratories in the then newly constructed MIT buildings and the use of the metallurgical laboratories, subject of course to the Institute's needs. After about two years this work was temporarily discontinued but was resumed in 1920 under the direction of G. H. Clevenger, consulting metallurgist for the Company, who recently retired. Becoming cramped for space, the laboratory was moved to a location near MIT on Amherst Street, Cambridge, in 1924. Establishment of a general research laboratory in metropolitan Boston naturally followed from the fact that the head office of the Company was located there and that the library facilities available for all types of research were, and are, unsurpassed. The disadvantages in carrying on research at great distances from the operating units of the Company were always apparent, but with widely scattered plants this disadvantage could not he overcome. With

Jan 1, 1948

By F. B. Plummer

PROGRESS during 1940 in oil-production technology has been confined largely to a steady advancement in practices inaugurated in previous years, rather than the introduction of any new startling process or technique. The usual changes, improvements and additions in production equipment have been introduced. An increased attention to, and interest in, research has been noteworthy, resulting in improved efficiency in operation of oil wells. control, utilization of reservoir energies and reduction of production costs.

Jan 1, 1941

By W. L. Honnold

AS BOTH South Africa and diamond mining are unfamiliar subjects it seems best that on such an occasion as this I should endeavor to reflect the atmosphere of the place and to picture the mines from an industrial rather than from a technical standpoint and, because of long absence, my remarks must necessarily be sketchy and in some particulars not up to date. The preferable route to South Africa is via England, direct steamers from America being inferior as to service and effecting no saving of time. The newer boats are of about 20,000 tons capacity and very comfortable. Seventeen days are required for the voyage and only one stop is made-that at the island of Madiera, three days out. Between Southampton, the port of departure, and Madiera the weather may be warm or cold and the

Jan 1, 1925

By Thomas R. Stauffer

The principle that conventional schemes for taxing petroleum or mineral resources are "inefficient" is illustrated using simulation calculations tested against an "ideal" system. Inefficiency is defined as the relative success in maximizing expected government revenues from the resources. Most systems fail because: 1) they leave oil in limbo, i.e. unproduced because of excessive fiscal burden; or 2) they unnecessarily increase the variance in the explorationist'c, rate of return by undertaxing large fields and overtaxing smaller but infra-marginal fields. This increases his discount rate and reduces taxable surplus. An "ideal" tax system is specified which maximizes government revenues while minimizing risk to the operator. Two criteria are developed: 1) the tax falls to zero on fields which yield only the minimum necessary rate of return ("marginal" fields); and 2) the after-tax present value of all fields is the same for all fields above a threshhold size. In particular, marginal fields, while contrib- uting little to expected values, do contribute to reducing variance and hence risk praemia by distributing the exploration costs over a higher probability of successful outcomes.

Jan 1, 1982