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ORE at the Jeffrey mine of Canadian John Mansville at Asbestos, Que., is hoisted by two 12 1/2 - ton capacity aluminum skips, counterbalanced. When the loaded skip reaches the surface it empties, via its sliding door, into a bin. Simultaneously, the skip tender, who operates at the 940 level, loads ore into the alternate skip from a 12 ½ -ton measuring pocket. This done, he sets the skips in motion. Problem: When moisture content of the asbestos ore is high, the ore, unknown to the skip tender, some- times sticks in the dumping skip, preventing complete discharge. Moreover, the sliding skip doors sometimes jam and stay open after the ore is discharged. If a skip in this condition is lowered, the result is either an overflow of ore, or the ore discharges through the open skip door, down the shaft. Spilled ore must then be mucked out of the spill pocket and hoisted in 2-ton cars. Cost is high, time is lost, and the shaft is sometimes damaged. Solution: A television apparatus was installed so that the skip tender might quickly spot improper door operation or hang-ups at the dumping station.

Jan 8, 1958

By A. G. Paithankar, G. B. Misra

Although certain physical mechanical properties of rocks have been claimed to give an estimate of penetration rate in percussive drilling, the authors' work shows that the correlation of penetration rate with individual rock properties is Poor. The authors have developed a good correlation between penetration rate and a set of rock properties but the relation is complex. Energy per unit volume has been used as a measure of penetration rate in percussive drilling by Hustrulid and Fairhurst; however, their test setup is large wing a full size drill bit. The authors determined the minimum energy for unit volume Ev min for any rock at the optimum index angle in a simple laboratory drop tester wing a sharp microbit with a tip angle of ll0°. This Ev min has been found to correlate well with penetration rate obtained in controlled laboratory drilling in different rocks for different stages of bit wear. A comprehensive relation has been developed between penetration rate and Ev min.

Jan 1, 1981

By A. Bar-Or, G. Hirsch, P. Wynblatt

The rates of nucleation and growth at various temperatures in U-0.45, 1.1, and 1.35 at. pet Cr alloys were determined, providing a qliantitative proo-f that the transformation under study is controlled by nucleation and diffusional growth. The linear relationship, log NV US 1/T2, suggests that the nucleation of the alloys is probably controlled by the classical law of nuclei formation. The established linear relationship, log G us 1/T, in the three alloys suggests that growth in each alloy is controlled by bidimensional nuclei formation. It was established that both the rate of growth and the rale of nucleation are retarded by chromium. Using classical formulae, sApN and sApG (the ß/a apparent interphase energies) were calculated from the nucleation and growth results, respectively. It was found that their values are of the same order of magnitude. However, why sApN is unaffected by the addition of chromium, while sApG increases with it, needs further clarification. In the last few years, an appreciable amount of research has been conducted into the mechanism of the ß —a transformation in uranium and uranium alloys. Recently, Burke1 reviewed the published work concerned with this transformation. He concluded that in dilute uranium alloys it is firmly established that, at high temperatures in the a range, ß decomposes by a diffusional process. However, he based his conclusion either on experiments dealing with the over-all transformation,2 or on qualitative results.3 It was felt that a better insight into the mechanism of transformation could be gained from the quantitative measurements of growth and nucleation rates, which we aimed to carry out in the present work. In a previous work,4 we have shown that a rim of a grains is formed during isothermal transformation at the high a range. The thickening of this rim with time was used for measuring the rate of growth in U-0.45 at. pet Cr.5 This method was also used in the present work for two more alloys. For meas- uring the rate of nucleation, a method of quenching and macroetching was developed to allow differentiation between a grains formed during isothermal transformation at the upper a range and those formed after quenching, Fig. 1. EXPERIMENTAL WORK AND RESULTS The Rate of Nucleation. The measurement of the rate of nucleation was effected by counting the num-

Jan 1, 1965

Jan 1, 1940

By O. C. Wheeler

The activity in exploration and in the acquisition of prospective oil lands that reached such a high level in Colombia during 1936 gained momentum and reached unprecedented proportions during 1937. Both national and private lands were taken up. In the Magdalena Valley above Puerto Berrio, leases on large tracts of private lands are held by Richmond (Standard of California), Shell and Texas. Tropical also owns leases covering a block of acreage in this area near Honda. From Puerto Berrio to El Banco most of the acreage is of national ownership, and concessions covering parts of this area have been granted to Tropical, Socony Vacuum, Shell and others, while applications for additional concessions are pending. Latterly leases on private lands below the Lebrija River have been taken out by Shell and Richmond. In the drainage basins of the Meta and Guaviare Rivers of the Llanos region of eastern Colombia, several of the major companies have carried on geological exploration and it is understood that some private properties have been leased or optioned. Under Colombian law, subsoil rights are reserved to the nation on all lands that passed from Government ownership after Oct. 28, 1873. Private titles antedating that day carry both surface and subsurface rights. Conditions under which lands may be acquired, explored and

Jan 1, 1938

By Sherwin F. Kelly

GEOPHYSICS may be considered a vice (albeit, I submit, a comparatively harmless one) whose career is aptly described by Pope's lines: Vice is a monster of so frightful mien, As to be hated needs but to be seen; Yet too oft, familiar with her face, We first endure, then pity, then embrace. Although there may be some that have not yet succeeded in emancipating themselves from the first stage of horrified contemplation, geophysicists may be duly thankful that there are mining men and geologists that have arrived at a state of apparently irretrievable damnation.

Jan 1, 1936

Jan 1, 1941

Jan 1, 1940

THE education of adolescents to perform the duties and assume the responsibilities of maturity has been a characteristic of human society since the dawn of history. In the beginning the members of the immediate family performed this function, and in modern life they still have an important part in it. Possibly religion was the first field in which education began to be functional; young people were sent for instruction to a teacher who had a broader and deeper knowledge of the subject than was possessed by the family. It does not seem necessary for our purpose to attempt to determine how, when, or where instruction in the practical arts first began to become functional, and the brief outline which follows must suffice. The discovery and utilization of mineral substances to improve and maintain the conditions of human living is a practical art, which must have had an almost accidental origin and have been developed by empirical experiments. We do not know, nor would it be useful to try to fancy, how men first learned that they could make use of mineral substances to their benefit, but however that knowledge was initially gained it was certainly trans- mitted through instruction in the family. At fist such activities must have been merely a minor part of the making of a living, bit in time those who excelled found it better to devote them-

Jan 1, 1941

By William Fink

MANY investigators have attempted to determine the true nature of the internal changes taking place during aging. Merica, Waltenberg and Scott1 were the first to propose a theory of age-hardening. They attributed the age-hardening of duralumin to the precipitation of minute particles of the compound CuA12. Later Zay Jeffries and R. S. Archer2 augmented the above theory by suggesting that the small CuA12 particles acted as "keys" causing "slip interference." Many other investi-gators3 have devoted much time to the mechanism of age-hardening, some corroborating the "precipitation" and "slip interference" theory, others coming to different conclusions because of effects that to them seemed unexplainable by the early theories; e.g., the increase of electrical resistance upon aging, the fact that no change in lattice parameter could be detected during the early stages of aging even at elevated tempera-tures, and the fact that the density did not change as would be predicted. In 1932, Merica revised4 his earlier precipitation theory to take care of these presumably anomalous effects. This revised theory, the "knot" theory, assumes that substantial age-hardening occurs before actual precipitation of solute as discrete particles. The assumed mechanism is one of diffusion of solute atones into groups forming distorted regions which act as "hard" spots and cause slip interference. These "knots" are assumed to have approximately the same lattice arrangement as the solvent.

Jan 1, 1936

By Mark R. Lamb

THE various methods of treating pulp in air-agitation tanks offer problems for experiment and study which are fascinating as well as practical. The usual method heretofore has been to fill each tank in turn, agitate the mixture the required period and then discharge the treated pulp into a storage-tank, from which it. is drawn to the filter as required. A later method is to run the pulp from the tube-mill, classifier, thickener, or settler into the first of a set of tanks, and thence continuously or in series through the remaining tanks, finally drawing off the pulp to a continuous filter, or to a pulp-storage tank if the filter is of the intermittent type. It is this method which I propose to discuss here in a preliminary way, with the idea of going exhaustively into the examination of the results of a series of experiments in a later paper. It may be of interest to note that the design of a cyanide-plant has recently been completed in which the estimated cost of the agitation-tanks, storage-tanks, and pumps was 30 per cent higher for the charge-agitation arrangement than for the series plan. The first question in studying the series method is, "What is the actual period of treatment undergone by the pulp?? One first supposes that by chance some of the pulp may get through with little or no treatment, while other portions may stay in the tanks a needlessly long period. The former is not probable or even possible, and the latter is, practically, true to only a limited extent. The greater the number of tanks the greater is the percentage of chance that all the pulp will be treated equally. Without going into the mathematical analysis of the problem (which is of little value, since it is based on problematical premises), its important terms may be clearly grasped by thinking of, or " visualizing," the conditions when,

Jan 1, 1910

CHICAGO SECTION CHAS. H. MACDOWELL, Chairman, LUTHER V. RICE, Vice-Chairman, HENRY W. NICHOLS, Secretary-Treasurer, GEO. P. HULST, ALEX. K. HAMILTON, FREDERICK T. SNYDER, HENRY P. HOWLAND. The Field Meeting of the Chicago Section proved to be the most enjoyable meeting ever held by the Section. It took the form of a visit to the Northern Indiana Industrial District where the day was spent inspecting metallurgical plants in Indiana Harbor and East Chicago and in amusement at the Hammond Country Club. The weather was perfect and about 50 members and ladies attended the meeting. An inspection of the plant of the Inland Steel Co. occupied the morning. The plant was decorated in honor of the occasion and the company provided attractive souvenirs. It was noticed here that many of the ladies displayed an interest in the inspection and an understanding of the processes that would not have shamed professional metallurgists. While the members of the Section seemed to be most interested in the by-product coke ovens and the by-product recovery plant, the ladies enjoyed especially watching the snake-like antics of the red-hot rods in the wire mill. Leaving the steel plant, the Section enjoyed a ride through the district by automobile and arrived at the Hammond Country Club in time for lunch. In the afternoon some of the members inspected the plant of the International Lead Refining Co., at East Chicago, while the rest spent the time at the Country Club in golf, tennis, trap shooting, bridge and other amusements. During the dinner at the Hammond Country Club an informally organized male quartette led the singing in real college boy style. In the evening, E. E. Billow talked on the use of oil burners in metallurgical furnaces, Mr. MacDowell told of the present status of the Potash Industry and the Secretary told of some of the happenings at the Arizona Meeting. HENRY W. NICHOLS, Secretary.

Jan 12, 1916

By M. Cohen, C. Wagner, J. E. Reynolds

If the total volume of a diffusion couple changes during the diffusion, the measurement of distance becomes ambiguous. Use of distance parameters as suggested by Hartley and Crank is discussed. For small concentration differences, the standard form of Fick's second law is retained with conventional length units and the in- terdiffusion coefficient D. It is shown how D can be calculated from experiments involving large concentration differences and analyzed in terms of distance parameters. 'The merits of incremental diffusion couples involving small concentration differences are emphasized. THE conventional form of Fick's second law for one-dimensional diffusion of component B in a binary solution of A and B is where c, is the concentration of component B; x, the distance; t, the time; and D, the interdiffusion coefficient which may depend on ca. Hartley and Crank' have pointed out that Eq. 1 applies only if the total volume of the diffusion couple does not change during the diffusion process; otherwise, the definition of x becomes ambiguous. No change in total volume takes place if the specific volume of the solution is a linear function of the weight fraction Wb, or if the molar volume is a linear function of the mol fraction N. In some alloys, however, these relationships do not hold, and then it is necessary to introduce a modified measure of distance, 4 in order to retain the general form of Eq. 1. The application of Hartley and Crank's suggestions to diffusion in alloys has been discussed by Wagner.' Relation Between Measure of Distance and Units of Concentration The definition of [ depends on the choice of units for the concentration c,, as follows: 1—If the concentration ca is measured as the weight fraction W, (or weight percent), [ = 5, has to be defined so that equal increments of contain equal increments of mass m of the solution, e.g., dm = pSdx = Sdw [2] where p is the local density of the solution, and S is the cross-sectional area in sq cm which is taken to be constant in this problem of one-dimensional diffusion." * da Silva and Mehla have demonstrated the constancy of the cross-sectional area in the usual type of diffusion couple. However, experiments involving diffusion into thin wires4, 5 may exhibit changes in cross-sectional area, and therefore are excluded from the present treatment. Thus and the unit of is gram per sq cm instead of cm. 2—If the concentration c, is the mol fraction N, must be defined so that equal increments of contain equal numbers of mols of solution, e.g., dn= (S/V)dx= Sd [41 where V is the local molar volume of the solution. Thus dt, = dx/V [51 and the unit of is mols per sq cm. 3—If, as may be advisable in the case of interstitial solutions, the concentration C is measured in terms of the molar ratio of components B and A (c,, = Y, = nH/nA, where n and nl are numbers of mols of B and A), = Y has to be defined so that equal increments of contain equal numbers of mols of A, e.g., dnA= (NAS/V)dx = Sdf [6]

Jan 1, 1954

By O. U. Bradley

The methods of handling the oil output of the Mid-Continent fields are not unlike those practised in other oil fields of the United States, and it is not expected that this paper will present any entirely novel ideas. Some features of the practice of handling this oil may be of interest, however. Wooden Gaging Tanks Practically all of the oil sold to pipe line? and other purchasing agencies throughout the Mid-Continent field is gaged from wooden tanks. Steel gaging tanks are slowly coming into use, and are preferable in many ways—leakage and evaporation are reduced, and the strapping and recalculation of capacities are unnecessary. The wooden tanks are slightly coned to facilitate tightening the hoops. The sizes in common use are 250, 500, 800 and 1600 bbl. The number and the capacity of the gaging tanks upon any producing oil property depend upon its production, and the facilities for disposing of the output. The 1600-bbl. size was the most common in the Cushing field, particularly during the period of flush production. The tanks are distributed over the leased premises in groups of two, three, and four tanks each, and these are filled from flow tanks, or through direct pipe connections with the heads of the wells. Flow tanks are merely temporary reservoirs to facilitate the transfer of oil from the wells to the gaging tanks. They diminish fire risk, and are considered indispensable on small producing properties where water is pumped with the oil, as they permit the refuse and water to 'settle out before the production is run to the gaging tanks. strapping and Calculations After a gaging tank has been strapped (measured) and its contents computed, a deduction of 3 per cent. is made from its computed volume. The strapping of a tank requires four steps: (1) The outer circumferences

Jan 1, 1920

By R. D. Saltsman

This paper deals with the evolution of a test procedure devised to totalize a coal's ignitibility, its degree of caking, and its coke reactivity and the development of a method for assigning proper combustion indices to stoker coals. The application of this type of work to stoker design is also discussed. It is believed that this work may be the prelude to understanding the effect of various petrographic constituents on the combustion characteristics of a coal or a blend of coals. The inadequacy of our knowledge of the coal combustion process has long been recognized. This was expressed very well by Spicer and Finney.1 "The control of combustion processes in industry and the design of the equipment necessary for efficient burning to take place have always been very much branches of an industrial art rather than of an exact science. This has been especially true of the utilization of coal, a substance so heterogeneous and complex in character that all too little is known about its chemical and physical composition." During the past several years one branch of coal utilization, that of high temperature carbonization, has made significant advances from being an art into being an exact science. This has been accomplished by the development of petrographic techniques for identifying, measuring, and determining the thermal properties of the organic materials which affect the carbonization of coal and the correlation of this information with a pre-existing standard of coke quality, the stability index. The success in using petrographic analysis for predicting the coking properties of coals and their blends suggested that petrographic techniques might be applied to the combustion process for predicting the combustion characteristics of coals. Certainly the different organic entities2 influence the combustion characteristics of a coal as they influence its coking properties. If it were possible to predict combustion characteristics from an analysis of a coal's petrographic composition, it would seem logical that an intelligent investigation could then be made into methods of altering stoker coals to improve their combustion characteristics. The successful application of petrographic analysis in the field of high temperature carbonization was made possible by the pre-existence of the stability index, which is a numerical value of coke quality. The quality of combustion is determined by the sum of the effects of the ignitibility, the caking, and the coke reactivity characteristics of a coal. While the literature is filled with papers reporting the correlation of various analyses to the ignitibility, or to the caking, or to the coke reactivity characteristics of coals, none of these earlier studies could be related to one index. The lack of a single index for combustion quality precluded the application of petrographic techniques for predicting combustion characteristics. SELECTION OF THE COMBUSTION TEST EQUIPMENT The primary prerequisite of any test developed to evaluate the relative performance of stoker coals must reflect the three characteristics of the coal burning process: 1) ignitibility, 2) degree of caking, and 3) coke reactivity. The widespread variations in these combustion characteristics of the available stoker coals are well known. The ignitibility, which has been defined as that characteristic which determines the ease with which the fuel may be brought to a condition of self-supporting active oxidation, varies from where a coal is deemed to be flashy to the opposite extreme of being fireproof. The ignitibility of a coal influences its ability to pick-up from hold fire, greatly affects the degree of bed stability during swing loads, and is a factor in determining the average burning rate obtainable on a given grate. The caking characteristic affects the degree of bed porosity during the devolatilization period, and coals are classified on a scale varying from free burning to highly caking. Caking is not synonymous with bed swelling since a bed may swell two to three times its normal depth during the period of devolatilization yet remain very porous, allowing an efficient and high rate of combustion to take place. Caking is melting

Jan 1, 1964

By W. H. Blauvelt

The only way in which the difficult problems of classification of coal for the manufacture of by-product coke can be solved is to analyze them by the use of scientific data. It is very easy to adopt classifications for coal for the manufacture of by-product coke along certain lines; we can easily say that for a certain class of metallurgical operation coke made from bituminous coal must not contain more than so much sulfur or more than so much ash and should yield certain returns in the by-products, tar, ammonia, benzol, gas, etc. Those points we are fairly clear on and I think it is hardly worth while to discuss them because I presume that they are familiar to most of us who have any occasion either to make coke or to use it. But there is a field in the manufacture of coke which we know very little about. For example, we are operating a plant on a certain mixture of coal. Suddenly our blast-furnace man or the user of the coke tells us the coke is not as good as it was before. The coke is analyzed and the coal is analyzed. Everything seems to be about the same as it was— the ash is the same, there is no more sulfur, and so on—but the coke, for the use to which it is put, particularly in the blast furnace, is wrong. What happens? The management decide to try a slightly different coal mixture. They do not necessarily raise the total hydrocarbons, the volatile matter in the mixture, nor change the sulfur or the ash, but they do make a change which improves the value of the coke for metallurgical use. The reason for this difficulty, as I see it, is the " combustibility " of the coke—I hesitate to use the word, but it is the best one I have available. Combustibility of Coke We know now that the combustibility of coke is a very vital point in many metallurgical processes and I think one of the most notable instances of the proof of this is the experience of the Carnegie Steel Co. in the production of coke at its Clairton plant. The history of that

Jan 1, 1930

By AIME AIME

TRAINED as a mining engineer and with no little experience in the field of mining, his interests and activities later transferred to the alloying, fabrication, and physical metallurgy of nonferrous metals, principally silver, Robert H. Leach represents in his professional life both of the major phases of the fraternity of mining and metallurgical engineers. In his personal characteristics, his wide circle of true friendships, his kindly, sympathetic interest in the problems of his fellow engineers, be they the junior men of the mineral industries or the mature and experienced men, he typifies the characteristics and attitude so desirable in the professional man.

Jan 1, 1939

By Rossiter W. Raymond

(Read at the Amenia Meeting, October, 1877.) IN the case of The Eureka Consolidated Mining Company v. The Richmond Mining Company of Nevada, recently tried at San Francisco, California, the real defendant was the Richmond Consolidated Mining Company, of London; but this being a foreign corporation, holds its mining property in Nevada through the Nevada corporation of similar name, in which the London Company owns all the stock, except the few shares necessary to "qualify" the American directors. The trial would naturally have taken place in the Circuit Court at Carson City, Nevada, and before a jury. But by stipulation of the parties, the case was tried in San Francisco, before Hon. Stephen J. Field, Justice of the Supreme Court of the United States, Hon. Lorenzo Sawyer, United States Circuit Judge of the Ninth Circuit, and Hon. E. W. Hillyer, United States District Judge, for the District of Nevada. The hearing began July 23d, 1877. The witnesses occupied two weeks, and the argument of. counsel three days. Very eminent lawyers were. engaged on both sides ; for the plaintiff, Messrs. Solomon Heydenfeldt, R. S. Mesick, John Garber, and H. J. Thornton ; for the defendant, Messrs. S. M. Wilson, Thomas Wren, and J. J. Williams. The court held the case under advisement until August 22d, when Mr. Justice Field delivered its unanimous opinion in favor of the plaintiff. The action was a complaint in ejectment, and an appeal was taken to the United States Supreme Court. The questions at issue between the Eureka and the Richmond Company in this suit, comprised several points in the construction of the mining law of the United States, and its relation to the customs and regulations of the mining districts, which possess an importance and an applicability far beyond the limits of the case in which they arose. It is my purpose to state these points, the arguments

Jan 1, 1878

By E. L. Ickes

DURing the summer and winter of 1918 eleven standard rigs were erected in the United Kingdom to test the petroleum prospects of- ten structures, eight of which were in England and two in Scotland. By the fall of 1921 ten of the wells were completed; the remaining one, the D'Arcy in Scotland, was stopped some months later. The tests were deep ones, five of the wells being 4000 ft. or more, the rest varying in depth between 1810 and 3918 ft. The total footage drilled was 40,047 ft. The holes were put down with standard or cable tools purchased in the United States (except the boilers). The larger sizes of casing, 10-in. and above, were also from America, while the smaller sizes were secured in Scotland. The Hardstoft well in England found a small production of high-grade oil and the D'Arcy well also encountered what is reported as a favorable showing at a depth of 1810 ft. The Werrington and West Calder wells had to be abandoned on account of drilling difficulties. The Apedale well encountered great thicknesses of ash in the Carboniferous and had to be abandoned on account of depth. The results might be summarized by saying that of the ten structures drilled upon, two yielded encouraging showings; three cannot be considered as having been adequately tested; and five produced dry holes, although in some of these small oil showings and gas were met. The total cost of the work amounted to about half a million pounds sterling, which sum includes the cost of all equipment, subsequently sold by the government. The work, under the superintendence of V. L. Conaghan, took place for the most part in the period immediately following the war—a period of high prices, labor and transportation difficulties, and unsettled conditions generally; factors tending to retard the work and affect the costs. The writer, as a member of the staff of S. Pearson & Son, Ltd., had charge of the administration of the work during its later stages and

Jan 1, 1924

By Sidney Powers, Alfred C. Lane

This paper aims to present the results of an investigation concerning gravitative differentiation in lava flows, based on a quantitative microscopic and chemical study of a Triassic basalt from Nova Scotia, and confirmed by data secured from a study of certain Keweenawan ophites. At Cape d'Or, Nova Scotia, near the head of the Bay of Bundy, marine erosion has exposed a series of Triassic basalt flows in which copper has been sought for a number of years. Studies of the thickest flow of the series with regard to volumetric composition, specific gravity, and grain have been made by the junior author, and measurements by students at Tufts College, together with confirmatory observations of the same nature on this and other flows by the senior writer, and chemical analyses made by the Division of Chemistry, Mines Branch, Ottawa,' all show differentiation in lava flows comparable to that in intrusive bodies. The work was made possible by the availability of the drill-cores, the property of Tufts College, and emphasizes the desirability of the study of drill-cores from other localities. Measurements of the specific gravities of certain Keweenawan lava flows of Michigan by the senior author, from material collected in 1915, will be given as a comparison to those of the Cape d'Or flow. It has been found that the specific gravity of drill-cores, or volume per cubic foot, can be readily obtained by measuring their dimensions. This can be done to an accuracy of within 1 per cent. in pieces of core over 100 mm. in length by using a micrometer gage for the diameter, and taking the average of six measurements of the diameter; and the average of four measurements of the length made with a finely graduated ruler. Then, after weighing them, the weight in grams per cubic centimeter, or what is practically the same thing, ounces per cubic foot, is obtained. System-

Jan 1, 1916