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By Dr. O’Neil Thomas J., Donald W. Gentry

Pure gold was hidden in the quartz, they said, 'Twas proved by dreams and signs, and rods divining, By chemic tests, and spirits of the dead, In fact by everything-except by mining. " from R.E. White, "The Mining Town," Alta California, August 18,1873 Textbooks in mining engineering have traditionally covered ore reserve estimation and mine valuation in a single volume. Indeed, Examination and Valuation of Mineral Property by R. D. Parks (1957), having been the standard of the profession for over 20 years, is a classic example. However, the state of knowledge in these two fields has grown tremendously. Most mining engineering curricula now cover these topics in separate courses, and in practice, these tasks are usually performed by different individuals. Thus, this trend now suggests the need for separate, specialized publications rather than a single volume for both topics. Because of the separate development of the science of ore reserve estimation, it is important to state at the beginning what this chapter does not cover. It does not address in detail the design of sampling programs, sampling methods, or the processing of samples or sample data compilation. There are a number of suitable references available on these topics, including Peters (1978), Gy (1979), as well as the previously cited book by Parks. Furthermore, this chapter does not cover in any substantial detail either the traditional methods for using sample data to calculate ore reserves or the more recently developed geostatistical methods. The traditional methods are thoroughly covered by Popoff (1966) and more concisely by Barnes (1980). Among the more useful references for statistical applications in ore reserve estimation are Barnes (1980), David (1977), and Clark (1979). A thoughtful review of the entire science and art of ore reserve estimation is provided by King, McMahon, and Bujtor (1982). In spite of the fact that expansion of knowledge now calls for separate books on ore reserve estimation and financial evaluation, neither publication can ignore the important interrelationships between the two fields. In regard to this text, the unique and crucial role of ore reserves can not be omitted entirely; however, the field is now simply too extensive to treat here in any comprehensive manner.

Jan 1, 1984

By Louis J. Demer, Paul A. Beck

As reported in a previous publication,1 isothermal grain growth in high purity aluminum and in an aluminum alloy with 2 pct magnesium can be adequately described by means of the empirical relation: [ ] or in some cases, by the simpler relation, [ ] Here, D is the average grain size after an annealing period t. The annealing period includes the time for complete recrystallization R, and the time for grain growth [to]. DA is the grain size as recrystallized, n is a parameter depending on the temperature and on the material. The effect of 2 pct magnesium in solid solution was to decrease D, and to increase R, A and n at a given temperature. The present work was undertaken in order to investigate the above listed effects of magnesium in solid solution, as functions of the magnesium content. The work also includes the study of certain anomalous effects observed in the recrystallization and grain growth of the 2 pct magnesium alloy at 350°C. EXPERIMENTAL PROCEDURE The method of producing the ingots used in this work was described in detail1 and need not be reproduced here. The materials used were high purity aluminum, furnished by the Aluminum Co. of America, of lot analysis shown in Table I and magnesium from a high purity distilled stock of magnesium crystals. [ ] Ingots were prepared for a series of binary aluminum-magnesium alloys of increasing alloy content. The numbers used to designate these ingots and their magnesium contents by chemical analysis are given in Table 2. [ ] The analyses showed no difference in composition between the top and the bottom of the ingots. Spectrographic analysis of the ingots for elements other than magnesium showed, within the limits of accuracy of the method, no increase in impurities over the amounts given in the lot analysis for the high purity aluminum in Table I. Careful microscopic study of ingot 21 in the as-cast condition, at magnifications up t0 1500X, revealed a cer-

Jan 1, 1948

THE paper on "Specific Efficiency of the Blast Furnace" by Richard Franchot, which was pub-lished in the September issue of MINING AND METALLURGY, was presented for discussion at the Pitts-burgh meeting. The session opened with a discussion among S. P. Kinney, Mr. Franchot, and J. N. Reese as to the methods and results in sampling for cyanides in the blast furnace. This is covered in detail in writ-ten discussion below. T. T. Read objected to the use of the term specific efficiency as likely to be confusing. The blast furnace has to perform the function of reducing Fe, 03 to Fe as well as that of fusing the metal and, since the reduc-tion of Fe, 0? involves a CO equilibrium, it seems mis-leading to calculate efficiency on the basis of burning the , all carbon to CO? since it is not possible. Mr. Franchot replied that he used the term in the sense defined by Richards in his "Metallurgical Calculations;" but a subsequent search failed to reveal the term in Richards, who says (page 245, 1st edition): The practical conclusion is that a blast furnace generates in itself not much over 40 per cent of the calorific power of the fuel used, and rejects nearly 60 per cent; by using part of the waste gases to heat the blast, however, some of this rejected heat, to an amount representing net 5 to 10 per cent of the calorific power of the fuel used, is returned to and injected bodily into the furnace, thus rendering available for the purpose of running the furnace about 50 per cent of the calorific power of the fuel as a maximum. The efficiency with which the furnace applies this 50 per cent usefully to the objects of the reducing and smelting is another question for investigation.

Jan 2, 1927

By C. S. Blair

THE development of a geological department as an integral part of the Tennessee Coal, Iron & Railroad Co. in the Birmingham district, Ala-bama, in 1908 was an innovation probably unique for any mining organ-ization south of the Ohio River, At that time a few of the oil companies were starting geological departments, but there were no geologists among the larger industrial organizations. The Tennessee Coal, Iron & Railroad Co. had been a substantial producer of pig iron for many years and was just getting a start in the manufacture of steel products from the pig iron. It had large acreages of coal land, ore land and timber land, but there was lacking the detailed knowledge of the possible mineral resources of much (of its territory, and this territory at that time covered an area in the neighborhood of 500,000 acres in the states of Alabama, Tennessee and Georgia. Those responsible for the operations of the mining properties, not being familiar with the kind of help that might be expected from geologic work, were decidedly skeptical of the utility of the work. Therefore it was necessary to develop cooperation with the mining organization, by not infringing upon its functions, and by developing the work in such a manner as to demonstrate to the mining department its practical utility. In the first instance the man responsible for a mining operation is apt to assume the attitude that the geologist is a blockader, because the geologist, unfortunately, is obliged to point out difficulties in the carrying out of mining operations in the way originally planned. He points out the dangers of mining out one coal or metal seam at the ultimate expense of an upper or lower seam, and he develops structural features, such as faults and folds, which call to the attention of the mining operator diffi-culties in his future operations, which the latter had not anticipated. Eventually, however, -the value of having these data became ap to the Tennessee Coal, Iron and Railroad Co., and the operators not only welcomed the geological work and cooperated fully in its acquisition of essential information, but reached the point of asking assistance and advice; and complete coordination of the two activities has existed for many years.

Jan 1, 1933

By H. H. Power, C. H. Pishny

When an oil operator becomes a party to a proration agreement he may wonder, with good cause, whether production prorated .today is merely deferred until tomorrow or whether oil might be lost. Various types of evidence obtained from production records when studied quantitatively are of great assistance in arriving at definite conclusions. A study of individual examples cited in this paper leads towards some solution of the problem, particularly when they are considered in the aggregate. Many production curves on various pay horizons were studied. A disappointingly large number of these were of contributory value, but inconclusive. However, there were enough curves of similar type from the Wilcox sand at Earlsboro, Bowlegs, Seminole City, the Cromwell horizon at Little River, and the Simpson dolomite at Valley Center, Kansas, from which reasonably definite conclusions were drawn. Assuming that deferred production is later made up with no increase in ultimate recovery, a curve (Fig. 1) shows the normal flowing and pumping life of a composite well, contructed by the family curve method. The initial production of the well shown is 1700 bbl. daily and the allowed production is 25 per cent. On this basis the average daily allowed rate for the first month is 425 bb1., or the area BCDE, which is equivalent to the area AFDG under the normal decline curve. The potential production for the second month is 1500 bbl. and the allowed production 375 bbl. daily. By this procedure a potential curve for each succeeding month is obtained (points A, H, I, J and K). If the well is opened it should produce somewhere near its potential curve for a short period and then decline at a more rapid rate than the potential curve. This theoretical analysis is basic. Actual examples exhibiting all points raised by the ideal curve are rare. Proration in the Mid-Continent area has been effected mostly by leases rather than by individual wells; hence a well may produce any

Jan 1, 1931

By William Hilliard

IN any manufacturing business, it is of vital importance that the management should know the exact cost of the units of production. Without such knowledge, a company can sell blindly in the open market, obtaining the best prices it can in competition with other firms, and manage perhaps to continue in business for a time; but at any moment, and especially in a period of falling prices, such a firm is at a loss to know exactly at what point it can sell at a profit and exactly how much it is losing per unit if it sells below that point. Furthermore, it is necessary not simply to know the exact total cost per unit, but to know definitely all the different-factors which enter into that cost. A firm manufacturing pocket knives had been doing a profitable business for many years when it began to earn smaller and smaller profits, until there was scarcely any profit at all being realized. Being unable to determine exactly what its future policy should be, it called in experts who studied the past records carefully and followed out for a period a better cost, system. Investigation then showed that on several different kinds of knives in common use, a small profit per unit was being made. On a number of special kinds of knives, of which the firm was very proud, it had been forced to cut prices under the pressure of outside competition and had believed that a small profit per unit was still being made on that product, while a detailed cost analysis showed that a loss was being incurred on each knife of that kind produced. It then became clear that the company must either give up the special line and concentrate wholly on the cheaper knives and extend their sales to territory not yet developed; or expand its plant and produce more of the higher grade knives and thus lower the cost per unit enough to make money on the higher grade knives also, if conditions warranted such expansion. Investigation revealed that the market for large quantities of the high-grade -knives was decidedly uncertain and that the most promising move would be to manufacture only the less expensive knives on a larger scale. That plan was carried out and the concern began again to make a better profit.

Jan 1, 1932

By E. T. Turkdogan, P. Grieveson

It is shown experimentally that, by making use of the coupled S-O reaction in ionic melts, it is possible to transfer slclJur or oxygen from a lozv to a high chemical potential through an ionic nzenzbrane. This uphill transfer of sulfur is accompanied by a counter downhill transfer of oxygen and vice versa. The Materials balance shows that the amoulits of sul -fur and oxygen lost or gained by one system are the same as those gained or lost by the other systenz — the two systejns being separated by an iofzic membmne. The systems used in these experi?nents were solid Mn-MnS-Mno and liquid Fe-S-0. Sufficient results were obtained Lo study the kinetics of the transfer and the indications are that the counter diffusion of sulfide and oxide iojzs in the membrane is the rate controlling process. WHEN an ionic oxide-melt reacts with an atmosphere containing sulfur and oxygen-bear ing gases the following reaction occurs: 1/2 S2 (gas) +O2- (melt) = S2- (melt) + 1/2 0, (gas) [1] Under the restrictions that i) electric conductance in the melt is purely ionic and ii) each constituent element in the melt does not change valence, the solution of an atom of sulfur in the melt will result in the evolution of an atom of oxygen, so that the electric neutrality is maintained. For a given temperature and melt composition, the equilibrium concentration of sulfur in the melt is determined by the ratio, po2 /ps2 , in the gas phase and not by the individual partial pressures of oxygen and sulfur. This has been demonstrated by a number of investigators, for example by Richardson and withers', Fincham and Richardson,la by St Pierre and Chipman,' and by Turkdogan and Darken.3 In his Howe Memorial Lecture for 1961, Darken discussed the possibility of uphill pumping of sulfur through an ionic membrane at the expense of oxygen. TO test the validity of this concept associated with coupled reactions, experiments were carried out in the following manner. A presintered mixture of Mn-MnS-MnO and prefused mixture of Fe-S-0, contained in platinum and iridium crucibles, respectively, and separated by a thin layer of soda-glass (to act as an ionic membrane), were placed side by side in an evacuated silica capsule and sealed. This was then kept at 1400°K for a required time to allow Reaction [11 to occur via the ionic membrane. When partial equilibrium is reached, the ratios Po2 /pS2, for systems on either side of the membrane, are equal and the flux of sulfur and oxygen through the membrane becomes zero, although the individual partial pressures po2 andp,, in these two systems may differ considerably.

Jan 1, 1962

By R. Ingerson

Bore surfaces of used guns commonly show a pattern of cracks in various degrees of development. It has been suggested that these cracks may aid erosion by providing channelways for the gases, eventually leading to the tearing out of blocks of metal. Under the general studies of gun erosion conducted at the Geophysical Laboratory it appeared desirable to consider this factor, and to determine the resistance to surface cracking offered by gun steel and by various other materials that might be used in the bores of guns. Method and Apparatus In order to make such a determination it is necessary to have (I) an arrangement in which the surface to be studied can be subjected to conditions similar to those in a gun with respect to temperature, pressure (developed by explosion gases), composition of the gases and length of time the surface is exposed to the gases; and (2) a specimen that can be examined readily after any number of shots, and then fired again, if necessary. The first of these conditions can be met by using an explosion vessel designed by H. S. Roberts of the Geophysical Laboratory. Fig I shows a cross-section of the apparatus. The "gun" G from which the charge is fired is made from the receiver of a caliber 0.30 army rifle, M1903, and the charges are prepared in caliber 0.30 cartridge cases. The test specimen S is held in place by a cone-shaped plug P and by a steel bridge B which is bolted to the outside of the explosion vessel on either side of the section shown. The plug, in turn, is held in place by a screw collar C. Maximum pressure is controlled by a brass rupture disk R. Part of the explosion gases flow past the two flat areas on S. Temperature and composition of gases, and the time before the rupture disk breaks, can be controlled by amount and kind of powder used, and pressure can be controlled by using rupture disks of different thickness. While the explosion vessel used was not designed so that temperature and pressure could be measured, in other vessels of closely similar size and shape containing proportionate charges of the same kind of powder as that used for standard testing procedure, values of 2700°K and 50,000 psi were obtained. Since the orifices past the flat areas on the plug are small compared to the rupture disk hole (I:I6), most of the gas goes out through the rupture disk when it breaks. The amount that goes by the plug depends on (I) the pressure attained before the rupture disk breaks and (2) the time it takes for this pressure to be built UP. The second condition (examination at will after any firing) is met by using for specimens short rods that have flat areas ground on opposite sides. These flat

Jan 1, 1949

By R. Ingerson

Bore surfaces of used guns commonly show a pattern of cracks in various degrees of development. It has been suggested that these cracks may aid erosion by providing channelways for the gases, eventually leading to the tearing out of blocks of metal. Under the general studies of gun erosion conducted at the Geophysical Laboratory it appeared desirable to consider this factor, and to determine the resistance to surface cracking offered by gun steel and by various other materials that might be used in the bores of guns. Method and Apparatus In order to make such a determination it is necessary to have (I) an arrangement in which the surface to be studied can be subjected to conditions similar to those in a gun with respect to temperature, pressure (developed by explosion gases), composition of the gases and length of time the surface is exposed to the gases; and (2) a specimen that can be examined readily after any number of shots, and then fired again, if necessary. The first of these conditions can be met by using an explosion vessel designed by H. S. Roberts of the Geophysical Laboratory. Fig I shows a cross-section of the apparatus. The "gun" G from which the charge is fired is made from the receiver of a caliber 0.30 army rifle, M1903, and the charges are prepared in caliber 0.30 cartridge cases. The test specimen S is held in place by a cone-shaped plug P and by a steel bridge B which is bolted to the outside of the explosion vessel on either side of the section shown. The plug, in turn, is held in place by a screw collar C. Maximum pressure is controlled by a brass rupture disk R. Part of the explosion gases flow past the two flat areas on S. Temperature and composition of gases, and the time before the rupture disk breaks, can be controlled by amount and kind of powder used, and pressure can be controlled by using rupture disks of different thickness. While the explosion vessel used was not designed so that temperature and pressure could be measured, in other vessels of closely similar size and shape containing proportionate charges of the same kind of powder as that used for standard testing procedure, values of 2700°K and 50,000 psi were obtained. Since the orifices past the flat areas on the plug are small compared to the rupture disk hole (I:I6), most of the gas goes out through the rupture disk when it breaks. The amount that goes by the plug depends on (I) the pressure attained before the rupture disk breaks and (2) the time it takes for this pressure to be built UP. The second condition (examination at will after any firing) is met by using for specimens short rods that have flat areas ground on opposite sides. These flat

Jan 1, 1949

By G. M. Ritcey, A. W. Ashbrook, E. G. Joe

Solvent-in-pulp extraction of uranium from acid leach slurries of flotation concentrates is described. Solvent extraction was carried out in a 10 in. diam pulsed-plate column. The extractant was a 0.1 M tertiary amine (General Mills Alamine 336) in a kerosene diluent containing isodecanol as an emulsion suppressor and third phase inhibitor. In pilot plant operation at the Beaverlodge mill of Eldorado Mining and Refining, Ltd., slurry feeds containing up to 35% solids were processed at a throughput rate of 13.5 tpd of dry feed. Uranium extraction obtained was as high as 98%. Amine losses to the raffinate were approximately 0.07 lb amine per ton of original dry feed. The Beaverlodge Mill of Eldorado Mining and Refining employs a carbonate leach for the extraction of uranium from the ore.',' Prior to carbonate leaching sulphides are removed by flotation to reduce reagent consumption. This flotation concentrate containing some uranium is then leached with sulfuric acid, filtered, and the uranium precipitated with magnesium hydroxide. The precipitate is then returned to the carbonate leach circuit. Although the tonnage of flotation concentrate treated by acid leaching is low, reagent costs are relatively high. Also maintenance costs on the acid leach filtration circuit were beginning to show significant increases. The choice of solvent extraction-in-pulp as an alternative to the present circuit was influenced by the following factors: 1) elimination of acid pulp filtration, 2) increase in overall recovery because of soluble loss elimination, 3) reduction of reagent cost (mill sodium carbonate solutions are used as strip), and 4) production of higher purity precipitate at the mill site. Because a solvent-in-pulp process would be difficult to test on a bench-scale, the Eldorado experience in the use of pulse columns,3-5 mixer-settlers,6 and solvent-in-pulp operations in particular7 was applied directly to the initial pilot plant carried out during the summer of 1965 and followed by the second pilot plant in 1966. The latter work, which is presented in this paper, determined the following factors for anticipated scale-up to plant production: 1) overall uranium recovery by this process, 2) tonnage throughput expected, and 3) solvent losses anticipated for the full-scale plant. The equipment used consisted of a 10 in. diam extraction pulse column and three mixer-settlers for scrubbing, stripping, and acid equilibration. All equipment was designed by Eldorado and much of the pilot plant was built at the mill site. PROCESS CHEMISTRY Feed to the acid leach plant consists of a sulphide flotation1,2 concentrate containing mainly pyrite, uranium and graphite, with a particle size of 90%

Jan 1, 1968

By E. V. Potter, E. T. Hayes, H. C. Lukens

LARGE volumes of hydrogen are liberated at the cathode during electrolytic precipitation of manganese. Most of the gas escapes from the electrolyte, but a considerable amount may be entrapped in the manganese plate. Gas has been observed to escape from manganese melts in puffs that ignite at the surface. It has been reported that castings made with electrolytic manganese tend to rise in the molds; for this reason the manganese is often treated to remove hydrogen before the melt is made or it is premelted and used as cast manganese in making the alloys. The effect of hydrogen on the properties of manganese and its alloys is not known, but its effect on iron and iron alloys has been studied extensively.1.2 The close relationship between iron and man¬ganese suggests that hydrogen may have a similar effect on the properties of manganese and its alloys. The purpose of this investigation was to determine the amount of hydrogen or other gases in typical commercial electrolytic manganese sheet and to investigate ways of removing it most conveniently. APPARATUS The apparatus used is shown schematically in Fig. I. It consists of a chamber A in which the metal sample is placed, a vacuum or pressure gauge B, volume gauge C, vacuum pump D, hydrogen container E, auxiliary gas chamber F, and furnace G. The specimen chamber was made of two concentric quartz tubes. The outer one, a, connects with the closed gas system and is surrounded by the furnace G. A second tube, b, fits closely inside a and has a small end that projects into the space for the specimen and holds the thermocouple for measuring the temperature of the sample. The inner tube is joined to the outer tube outside the furnace, with rubber tape and sealing wax, to prevent gas leakage into or out of the closed system. This type of specimen container is loaded very easily and can be used several times if molten metal does not come in contact with the quartz. An ordinary mercury manometer B is used to measure the pressure in the system. The volume gauge C is essentially another mercury manometer, but the volume of the column is much larger than normal and the height of the mercury can be varied by raising or lowering the well H. In this apparatus the tube had a volume of I00 c.c. for a 60-cm. length. For larger changes in gas volumes; auxiliary containers F were used to increase the volume of the system by known amounts. Valves were arranged so that these auxiliary containers could be filled from the system and evacuated by the pump as often as necessary to accommodate the increases in the volume of gas in the system. The furnace G, used to heat the samples, was equipped with an automatic temperature controller, which maintained the desired temperatures within ± 5°C.

Jan 1, 1945

By John D. Sullivan, Edwin J. Rogers, Chester R. Austin

THE problem of making a building unit combining the necessary physical and mechanical properties and good thermal insulation has been foremost in the minds of architects and ceramic and construction engineers for many years. This paper presents the results of studies on thermally expanding shales or clays to produce light-weight cellular products suitable for making building units. An expanded clay block suitable for building purposes should be large enough so that substantial savings may be effected in labor costs in laying the wall. The permeability should be low and it should have sufficiently good "dry-wall" characteristics to permit exposing the exterior surface to the elements, and to permit plastering directly the inside wall surface. The thermal conductivity should be low and the mechanical properties should be adequate. Obviously, a unit possessing satisfactory qualities for constructing an outside wall would be satisfactory for interior walls and for back-up purposes. The results of studies on bloating various shales or clays† and the properties of the expanded products are reported. In another paper1 basic factors involved in bloating of clays are discussed. Manufacturers of ceramic products, particularly structural clay, may encounter bloating of the ware during burning, and precautions must be followed to avoid this phenomenon. About 1927 the C. F. Burgess Laboratories, Madison, Wis., while carrying on an investigation for the American Face Brick Research Corporation, conceived the idea of intentionally bloating clay while holding it in a restrained condition, with the hope of producing a unitary cellular mass. Work was carried on until about 1931, when studies were terminated because of business conditions. These studies were continued later by The Western Brick Co., Danville, Ill., which developed a process of "inwardly expansive bloating." The major purpose of the latter investigation was to produce back-up tile to compete with concrete blocks made from Haydite or cinder aggregate. Haydite is a light-weight aggregate formed by heating certain clays or shales rapidly in a rotary kiln. While the investigations at the C. F. Burgess Laboratories or at Western Brick Co. were not carried far enough to lead to the commercial production of material for the construction of walls, particularly outside walls, they showed that certain clays could be thermally expanded and that it was possible to produce a material of low permeability with a large percentage of the total voids or cells closed. Commencing in 1939, the Ozark Chemical Co. sponsored a research program at Battelle Memorial Institute for the purpose of determining whether it is technically feasible to make thermally expanded building units, and specifically to get answers to the following questions:

Jan 1, 1942

By C. A. Heiland

The following summary is written for the benefit of the practical operator in the nonmetallic field who wishes to know what geophysics has done and may be expected to do in his line of work. His problem is quite different from that of the geophysicist who has operated with various or all methods and has followed the literature, and who is assumed to be familiar with the geologic possibilities and limitations of each method. This article is not written for the latter, although he may be interested in the four or five hitherto unpublished surveys described. To the operator, on the other hand, geophysics is only secondary. His problem is to determine which geophysical method is best suited to his special needs. If he wanted to know, however, which method could be used to locate a certain material of given physical properties, building stone, for instance, he would have to wade through a tremendous amount of geophysical literature, bibliographies and articles, before he could find what he wanted. Therefore, the purpose of this summary is to present the geological problems first and then to discuss the comparative merits of the geophysical methods that can be, or have been, applied. Choice of Geophysical Methods in Oil, Civil and Mining Engineering In the first two of these fields, the geological problems are not nearly so complex as in the metal and nonmetallic mining fields. The selection of the correct geophysical method in these fields is not nearly so difficult for the operator. For oil prospecting, his problems have been discussed exhaustively by E. DeGolyer.(1) † In civil engineering (foundation and ground-water work), the usefulness of electrical methods has been so well established that there is hardly any choice of other methods at present. The situation may be changed in the future with the perfection of the seismic reflection method for shallow depths. In the mining field the operator and often the geophysicist himself finds difficulty in determining which method is best suited for a given

Jan 1, 1934

By A. C. Wallace

THE development of the natural resources of any district of any magnitude, inevitably gives rise to many problems off title, usually due to the greatly enhanced value of the land. The development of the mining industry in the Quapaw Agency has been no exception to this general rule. Our problems, how-ever, have not been many or particularly serious. The Quapaws were allotted and patents issued by the United States Government in 1895. These patents contained a restriction against alienation for a pe-riod of twenty-five years. The effect of the restric-tion was to prevent the Indian from selling, leasing, or in any way encumbering his land. The Govern-ment, in a paternalistic spirit, sought to teach the Indian thrift and industry and to insure him a place of residence. This is evidenced by the first Leasing Act passed by Congress, which permitted only incom-petents and those physically disabled to lease their land for either agricultural or mining purposes. The able-bodied Indian was denied the right to lease. It soon became apparent to the Government, how-ever, that this was a mistaken policy, and in 1897 a General Leasing Act was passed by Congress and it was under this act that the mining industry in the Quapaw Agency was developed. The act, reads as follows: "That the allottees of land within the limits of the Qua- paw Agency, Indian Territory, are hereby authorized to lease their lands, or any part thereof, for a term not ex-ceeding three years, for farming or grazing purposes, or ten years for mining or business purposes. And said al-lottees and their lessees and tenants shall have the right to employ such assistants, laborers, and help from time to time as they may deem necessary: Provided, That when-ever it shall be made to appear to the Secretary of the Interior that, by reason of age or disability, any such allottee cannot improve or manage his allotment properly and with benefit to himself, the same may be leased, in the discretion of the Secretary, upon such terms and conditions as shall be prescribed by him. All acts and parts of acts inconsistent with this are hereby repealed." It was the interpretation of this Act that gave rise to our first serious problems. It will be noted that the Act says that "allottees of land" within the limits of the Quapaw Agency are authorized to lease their land. Thus, the first question was presented by the use of the term "allottee," and the question was as to whether or not Congress intended to limit the Quapaw Indian to the leasing of his own allotment or did Congress mean that the term "allottee" was synonym-ous with "Indian" and intend to give the Indian a right to lease both his allotment and his inherited land and was an Indian without an allotment an "allottee" even though he was a member of the Qua-paw tribe and the owner of the Quapaw land by in-heritance, and not being an allottee, could he lease his inherited Quapaw land under the authority granted in this Act?

Jan 5, 1928

By E. C. W. Perryman

The recovery of X-ray line broadening, hardness, and electrical resistivity from cold worked AI-Mg alloys has been investigated. The results, together with those from density measurements, suggest that magnesium atoms freeze in the excess vacancies formed by cold working, and that this affects the climb of dislocations during the recovery process. PREVIOUS work1, " has shown that while 1 pct Mg increases the activation energy for recrystalliza-tion, it decreases the activation energy for the recovery of mechanical properties and decreases the subgrain size both after cold working and annealing. A similar result has been reported by Varley2 for an A1-2 pct Mg alloy. With plastic deformation at high temperatures, McLean and Farmer' and Rachinger have found that magnesium appears to retard the motion of dislocations and, furthermore, they find little or no effect of magnesium on the size of subgrains formed during high temperature deformation. In view of the apparent contradictions as to the effect of magnesium on subgrain size, the recovery process in Al-Mg alloys has been investigated more thoroughly by studying the annealing out of X-ray line broadening, hardness, and electrical resistivity from alloys cold worked at room temperature. Material Used—The chemical analyses of the alloys are given in Table I. Fabrication—The material used was cold rolled 20 pct at room temperature, the grain size prior to the last cold rolling operation being similar to that used in previous work; i.e., 230. The experimental procedure for annealing, determination of X-rav half-veak breadth. hardness measurement, electEica1 resistivity, and density and metallographic examination was exactly the same as previously described." Variation of X-Ray Half-Peak Breadth with Annealing Time—Isothermal annealing curves at 100°, 200°, and 250°C were obtained for material cold worked 20 pct. The half-peak breadth of the (333) Ka, line directly after cold working is shown as a function of magnesium content in Fig. 1. Only with the 2.87 pct Mg alloy was overlapping of the a, and n.. reflections observed to any appreciable extent. To separate these, Rachinger's method' was used. Typical isothermal annealing curves are shown in Figs. 2 and 3 for 100" and 200°C, respectively. These curves are similar to those obtained previously for super-purity aluminum except that the

Jan 1, 1957

By James Terry Duce

The symposium on production for the year 1940 contains few papers on the foreign situation. It is probable that the foreign part of next year's symposium will be even shorter. This is due to rigid censorship in various countries, as the question of the volume of petroleum supplies has become one of great strategic importance. This is even more true than in the last war, owing to greater mechanization of armies. 'It has always been the policy of officers in charge of the symposium to refrain from publishing information that might possibly injure national or private interests. At the close of the war we hope again to publish full and accurate records of production abroad. Excerpts from Circular to Authors In order to facilitate interpretation of the data in this chapter, we print the following excerpts from the Circular to Authors. The field is the unit in this tabulation. In cases of fields extending across State boundaries, such as Rodessa, it is suggested that each State author treat the section of the field in his State as a unit, and by a footnote indicate that the field extends into an adjacent State. Each space in Table I may represent one of four possibilities; either it is not applicable to the particular field, or the proper entry is not determinable, or the proper entry may be determinable but is not determinable from data available to the author, or the proper entry is determinable. When spaces are not applicable, leave blank; in spaces where the proper entries are determinable but not de-terminable frod data available to the author, please inserty; in spaces where the proper entries are determinable by the author, make such entries. y implies a hope that in some future year a definite figure will be available. The entry of a zero is a positive declaration, and an important declaration where it is in order. Inability to determine precisely the correct entry for a particular space should not lead the author to insert merely y. Contributions of great value may be made by the author in many cases where entries are not subject to precise determination. In sucli cases the author should use his good judgment and make the best entry possible under the circumstances. For many spaces the correct entries represent the opinion of the author (for example, "Area Proved') and in such cases the entry need not be hedged to such extent as when the quantities are definite yet can be ascertained only approximately by the author. In cases under definite headings but where figures are only approximate, the author may use x. It is thought that the nearest whole numbers are sufficiently accurate for our purposes except as to percentage of sulphur in oil. If an author desires to report any other figures to tenths, he may do so. The quantity of gas produced should include, where possible, gas sold or otherwise marketed, and gas blown into the air, burned as flares or otherwise wasted. Segregation of these figures would be interesting if the authors can make such segregation. In any event, the figures should represent as nearly as possible the total quantity of gas removed from the reservoir. Under the columns on "Depth," the average depth to the top of the productive zones and to the bottom of the productive wells, when

Jan 1, 1941

By H. I. Aaronson, H. A. Domian

The self-diffusivity of Ag10 has been measured as a function of temperature and composition in AgMg. a CsCl-type intermetallic compound with a substitutional defect structure on both sides of the stoichiometric (50 at. pct Mg) composition. These measurements show that In D increases linearly, and both In Do and Q decrease linearly with deviation from stoichiometry. The slopes of these lines are significantly steeper in magnesium-rich alloys. Equations for the variation of Q with composition have been derived by application of the theory of random walk processes on the assumption that diffusion in compounds of this type takes place by the six-jump cycle mechanism of Huntington, Elcock, and McCombie. The favorable agreement obtained with experiment furnishes fresh support for the correctness of this assumption. A principal result of this treatment is that. although the concentration of vacancies is considerably higher in the silver sublattice than in the magnesium sublattice, the acfivation energies for movement of the magnesium sublattice vacancies are so much lower that these vacancies are responsible for effectively all diffusion of silver in this compound. A tendency for vacancies of both types to be kinetically bound to wrong atoms is also noted. THIS study was undertaken to examine the influence of substitutional defects upon self-diffusion in an intermetallic compound, AgMg, with a CsCl-type crystal structure. The CsCl structure is exception- ally simple. At the equiatomic or stoichiometric composition in a binary alloy, it consists of two interpenetrating simple cubic sublattices, each of which is exclusively populated by the atoms of one species. When atomic size and other factors are favorable, deviations from stoichiometry can be entirely accommodated by the substitution of atoms of the species present in excess of 50 at. pct on the sublattice of the other species on a one-for-one basis. Under this condition, the only vacancies present are those formed by thermal activation. The excess atoms thus incorporated into the sublattice of the minority species may be considered as substitutional defects in this sublattice. Several X-ray studies have shown that the defect structure of AgMg is entirely of the substitutional type on both sides of the stoichiometric composition.1"3 The thermodynamic investigation of Kachi indicates that, aside from a low level of thermal disorder and these constitutional defects, order is maintained to the solidus temperature. This compound is therefore a particularly useful vehicle for a study of the influence of substitutional defects upon diffusion kinetics. Other advantages of AgMg for this purpose include: the broad composition region, as much as approximately 10 at. pct on either side of the stoichiometric (50 at. pct Mg), in which the compound is stable; the comparatively low temperature range of the solidus (820°C and below),5 making diffusion anneals near this range experimentally convenient; the reasonably good machinability of the compound, permitting utilization of the standard sectioning method of radiotracer analysis; and the availability of a good tracer, A for one of the constituent species. While this investigation was in progress, Hagel and westbrooks reported data on the self-diffusion

Jan 1, 1964

By J. E. Kirby, L. B. Schnitz, H. E. Stamm III

The production history of a gas-cap-drive reservoir was reproduced by calculations, and predictions were made for operations under primary depletion, pressure maintenance by gas injection, and pressure maintenance by water injection. Although the general equations used in this analysis have been available to the industry for a number of years, the procedure has not had extensive use because of the unusually large time requirements for developing numerical results. The use of digital computing equipment for processing the calculation work generally reduced the time usually required for an extensive analysis of this type. Calculation techniques were developed that were equally applicable for solving the gar-cap-drive problem, whether digital computing equipment or desk calculators are used. These techniques are outlined and the procedures are illustrated by the field problem. INTRODUCTION The analysis of a gas-cap-drive res-ervoir requires the simultaneous solution of the volumetric balance1 and displacement2 equations. Equations for the analysis of combination drive reservoirs were presented by Wooddy and Moscrip in a previous paper." These equations permit the evaluation of possible operating processes in order that the optimum method of pro- ducing the reservoir may be determined. Although these equations represent the basic technique known for the detailed analysis of gas-capdrive reservoirs, the calculation processes are quite complex and time consuming; hence, the procedure has not had extensive use. Recently, these equations were satisfactorily applied with the aid of a digital computer to investigate the completion history of a gas-cap-drive reservoir under the following operating methods: primary depletion, depletion under full pressure maintenance by gas injection, and depletion under full pressure maintenance by water injection. The use of digital computing equipment substantially reduced the time necessary for making the computations and permitted a more concise investigation of the reservoir's depletion history than was possible when the desk calculator was used. This more rigorous investigation also permitted a detailed analysis of the calculation procedures necessary in the solution of the gas-cap-drive problem. This paper outlines the procedure of analyzing a gas-cap-drive reservoir and illustrates the process with an actual field problem. CHARACTERISTICS OF THE RESERVOIR ANALYZED Production in the field under consideration is obtained from a Frio formation of Oligocene age at a depth of approximately 5,740 ft sub-sea. The accumulation, which is bounded on the flanks by strand lines, is semirectangular in shape with gentle narrowing toward the base of the structure as shown by the sand limits and completion map in Fig. 1. The reservoir development indicates an oil column of 319 ft that is defined by gas-oil and oil-water contacts. Basic data relative to the characteristics of the formation and the formation fluids are shown in Table 1. The formation exhibits considerable shaliaess and thinning near the oil-water contact indicating that little or no benefit will be received from natural water influx. This is substantiated by the fact that wells completed near the original oil-water contact have not produced water. A sizeable gas cap is present; however, considerable faulting is in evidence, and it is believed that only a limited portion of the gas cap will aid in oil displacement and pressure maintenance. Although the reservoir was in an initial stage of depletion, it was believed that as soon as the equilibrium gas saturation in the oil zone was exceeded and a number of upstructure wells were invaded by the expanding gas cap, the resulting high gas-oil ratio production would rapidly dissipate the natural drive and lead to limited oil recoveries and inefficient reservoir operation. This analysis evaluated the effectiveness of the primary displacement mechanism and

Jan 1, 1958

By R. W. Kraft

A back- reflection precession-type X-yay camera for determining the crystallographic orientation of the crystallites of both phases in small areas of thick specimens of polyphase alloys is described ad the geometry, advantages, and limitations of the apparatus are discussed. Metallographic obseg-vations of interfacial angles (or habit planes or growth direction are made on the same specimen so that the crystallographic and metallographzc orientation data call be directly correlated. An example of the application of tile technique to a unidi-~~ectionally solidified CuA12-A1 eutectic specimen is presented. The interfacial planes ad growth directions of each phase were established, and the orientation relationship between the phases was observed and found to be approximately intermediate between two previously reported relationships. The crystallographic interfacial relationship between two solid phases is an important parameter in a variety of metallurgical phenomena because of the energy associated with the interface and because this energy is at least partly associated with the way in which the two space lattices are in contact along the interface. In order to describe the interfacial planes in the crystallites of both phases it is necessary to determine the crystallographic orientation of each phase in a specimen relative to each other, and to directly correlate these data with met-allographic measurements from which the interfacial planes can be determined on the same specimen. The back-reflection Laue technique is the easiest way to determine the orientation of thick single crystals or large grains and the method can be combined with metallographic techniques to provide the necessary data, provided the reflections from each phase can be distinguished from one another. However, if the crystallites are small or of varying orientation or if one or both phases has a unit cell with less than the maximum symmetry, many overlapping and complex Laue patterns are recorded simultaneously and it becomes impractical if not impossible to interpret the photographs. All of these complexities were present in a unidirectionally so- lidified A1-CuA12 eutectic alloy1 for which a crystallographic analysis was desired. Consequently the method described here was developed since no known X-ray or electron diffraction technique had all of the following attributes which were required. 1) Method should yield data from which the crys-tallographic orientation of every crystallite or diffracting unit in the irradiated area can be determined. 2) Method should be adaptable to the study of small areas. Depending upon the degree of preferred orientation in the specimens, it should be possible to obtain reliable data in a reasonable length of time on irradiated areas as small as 1.0 or even 0.1 mm in diam. 3) Method should permit direct correlation of crystallographic data with microscopic orientation data pertaining to crystallite axes, habit, morphology, and growth directions as determined by optical microscopy. 4) method should be such that selected areas of large specimens can be easily studied. Trepanning of a small specimen (such as an electron microscope specimen) from larger specimens was undesirable since it would greatly increase the problem of correlating the crystallographic and microscopic directional data. Requirements 3 and 4 dictated that an X-ray back-reflection pinhole technique should be used on large samples, such as metallographic specimens which had previously been examined and analyzed for their microscopic characteristics. Similarly, requirement 2 could be satisfied by choosing a collimator of appropriately small diameter. Exposure times would not be excessive provided the detector were close enough to the specimen. Because of space limitations film was chosen in preference to a Geiger counter. Requirement 1 was fulfilled by using monochromatic radiation and providing enough additional degrees of freedom in specimen rotation to compensate for Bragg law restrictions on diffracted beams. DESCRIPTION OF APPARATUS The apparatus shown in Fig. 1 consists of a pin-hole collimator, (a), projecting through a rotatable circular film in a holder, (b), which records X-ray reflections in the back-reflection region. The specimen, (c), is mounted on the end of a shaft, (d), which is provided with an adjustment, (e), so that the specimen surface can be placed accurately on

Jan 1, 1962

By W. F. Mullen, C. W. Stickler

WITH few exceptions, unit operations in the Pennsylvania slate industry in 1950 did not differ appreciably from production methods described by Behrel and Bowles2-4 several decades ago. Many traditionally picturesque but relatively inefficient hand operations continued to contribute to high operating costs in an industry in which the margin of profit, for various reasons, was admittedly low. As part of a general program in which the Pennsylvania State College has been assisting the slate industry to solve some of its problems, time and method studies were used in an effort to determine the bottlenecks of production flow. The results are as applicable to other stone industries as they are to slate. A study of the basic elements in the production of roofing slate, structural slate, and slate blackboards among selected slate producers revealed comparatively few refinements. Any marked difference in operating method was characterized largely by the available equipment, a noticeable difference in the working properties of the rock quarried by a particular company, and by either the habit thinking or ingenuity of the individual operators. With the hope that significant economies in manufacture might result, all the unit operations were broken down into elements for study and analysis. The greater part of the study encompassed those operations from the quarry rim to the finished product; however, to obtain a reasonable synthesis of time allotments per operation, several analyses of quarrying from the finish of the wire saw cut are included for reference. The complete study of quarrying made by Bowles several years ago resulted in the introduction of the wire saw into the operation; there appears to be a need for as fundamental a change in the processing of finished slate as the wire saw was in the quarrying process. Fig. 1 illustrates the flowsheet of quarried rock from the parent bed to the quarry rim with the basic elements which contribute to the difficulty of removing slate from the ground. In Pennsylvania roofing slate is produced by one of three procedures, many operations of which are quite similar. In the traditional or classical method the quarried rock is reduced by sculping and auxiliary manual treatment to workable size and then is split and dressed (trimmed to size) in the conventional shanty. Archaic as this method might appear, there are several elements that result in substantial savings over more mechanized operations. In a modified version of this method, the block is reduced by sawing and gouging preparatory to splitting and dressing in indoor stations. This method is particularly adaptable to rock which fractures unevenly by conventional sculping methods. In the third and more modern method, reduced block received from the block maker is diamond-sawed to length and finished on a production line. Fig. 2 illustrates the flow pattern in each case. In the modified and more modern plans, dressing is done on mechanically-operated trimming machines, which appreciably reduce the fatigue factor of the operator. However, it should be noted that it is advantageous for the operator to be able to control the speed of the knife to prevent breakage of certain classes of stock. In the classical plan the splitter and dresser normally act as blockmakers also and carry their eighter slabs (equivalent in thickness to eight shingles) into the shanties themselves, all of which adds to fatigue and reduced efficiency. The extremely low investment and operating expense of the classical method has undoubtedly been of paramount importance in its continuation. Production of Mill Stock The production of mill stock is accomplished by less picturesque methods than enter into the production of roofing slate but it is, in the main, relatively more efficient because of the increased use of machinery for handling and for finishing. Mill stock can be classified into two categories as far as difference in production method is concerned: structural slate and blackboards. The significant difference in operation is caused largely by the nature of the rock used for each product with the best and easiest cleaved rock being reserved for blackboards to permit the splitting of large slabs to as little as 1/2 in. in thickness. Structural stock, on the other hand, is split into panels no thinner than 11/2 in. and

Jan 1, 1952