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By Alan English

INTRODUCTION During the Bicentennial Year in the United States of America, recognition should be given to the fact that 20 years ago the first large-scale commercial pelletizing plant was started and attained rated capacity. This was the beginning of a new industry. Twenty years ago the total production of pellets was principally from pilot plant facilities and totaled in the thousands of tons per year. At the present time the world production is slightly in excess of 280 million tons per year. This truly is a tremendous growth for any industry. Such a production growth obviously is accompanied by a similar growth pattern in the development of process, equipment, and facilities. During the growth and development period, different materials became more adaptable for processing. For example, initially the pelletizing of iron ores revolved around the magnetite concentrates where the heat of reaction constituted a very important part of the process fuel. During this growth period, specular hematite, earthy hematite, mixtures of hematite and magnetite, and even non-ferrous type materials were pelletized, a function previously thought not practical. The demand for the use of pellets has also broadened their concepts. At first they were made to replace the high-grade iron ores used in blast furnaces. Nowadays, not only have they replaced iron units, but they have had a major influence on the design of larger blast furnaces and have contributed to production rates in excess of 10 000 tons per day from a single furnace. They have also been used in the manufacture of steel, principally for coolants in the BOF practice. More recently, with the improved beneficiation techniques that have been developed over the same period of time, pellets have been used for the direct reduction process and can be used directly

Jan 1, 1977

The earliest record of coal in Indiana is one of the earliest in the country. At the close of the French and Indian War, in 1763, the famous Indian trader, George Croghan, was sent from Pittsburgh on a mission to the western Indians. His party met that of a hostile chief on the lower Ohio and was captured, and were taken up the Wabash River; on June 22nd, he passed the mouth of the Vermilion River-probably the Big Vermilion-and on June 23rd, he made the following entry in his journal: "on the South Side of the Ouabache runs a high hank, in which are several very fine coal mines, and behind this bank, is a very large meadow, clear for several miles."' The mines, of course, were outcrops. A few days after this he met some Indian acquaintances who secured his freedom. This location was at Ouicatanon, 210 miles from "Port Vincent," which was destroyed a few years later, and in what is now Fountain County, probably near Coal Creek. Croghan was familiar with the coal already being worked at Pittsburgh. Surveyors who ran the township and section lines in the first ten years of the last century noted the presence of coal and marked its position on the maps in 1804.2 The next record is by Nicholas J. Roosevelt, who in 1809 examined the Ohio and Mississippi Rivers prior to starting building the first steamboat to navigate these rivers. "Not only did he do this, but finding coal on the banks of the Ohio, he purchased and opened mines of the mineral; and so confident was he of the success of the project on hand, that he caused supplies of the fuel to be heaped upon the shore, in anticipation of the wants of a steamboat whose keel had yet to be laid."3 It is probable that this account confused the date of seeing the coal with that of mining it, as an earlier account by another relative of Mrs. Roosevelt of the first trip of the steamboat New Orleans in 1811 is as follows:

Jan 1, 1942

By Morris Cohen

WITHIN the past two years, a number of publications have called attention to the double peaks, or stages, that appear in the hardness and strength curves of certain aging alloys. The author has shown the existence of double hardness peaks during the aging of a high-purity silver-copper alloy;1 and on the basis of electrical resistance, microscopic, dilation and lattice-parameter measurements, he concluded that the initial hardness peak occurs prior to precipitation while the secondary hardening is due to precipitation. It was suggested that the general mechanism of age-hardening involves two consecutive processes, the first consisting of nucleus or knot2 formation, and the second consisting of actual precipitation and particle growth. It was further held that the two stages are interdependent, but because of nonuniform precipitation they may overlap each other to an extent that increases as the aging temperature is raised. At high aging temperatures, the effect of the first stage cannot be detected because of the rapid occurrence of precipitation. The general theory of age-hardening recently presented by Dr. M. L. V. Gayler3 is in close agreement with the picture outlined above. With reference to work done on duralumin, copper-beryllium and copper-silver alloys, Dr. Gayler also concluded that age-hardening takes place in two consecutive steps: first, diffusion (in which the solute atoms migrate to certain crystallographic planes), and then precipitation. However, W. L. Fink and D. W. Smith4 have shown that the double aging peaks that appear in the strength curves of high-purity aluminum-copper alloys may be explained without recourse to pre-precipitation phenomena. By means of very careful metallographic technique, Fink and Smith demonstrated that during aging the precipitation takes place at an accelerated rate along the grain boundaries and slip planes as a result of the plastic deformation caused by the drastic quench from the solution heat-treatment temperature. ? The general precipitation occurs at a

Jan 1, 1938

By Earl Oliver

Superficial observation of the petroleum stabilization movement in 1932 is disappointing. Threatened overproduction persisted; waste continued; proration was violated; gasoline taxes were evaded; and, as a consequence, chaos threatened the industry as the year drew to a close. However, comparison of the movement in 1932 with its beginning a few years ago, and analyses of those influences that promote its growth as well as those which retard it, disclose some reasons for encouragement. Stabilization, as we see it, is not merely a mechanical engineering problem. It involves social engineering. By which we do not mean it is possible, or even desirable, to change the nature of men, but rather that it is possible to set up procedure that will avoid causing them to clash. It comprehends consideration of physical objects that is clearly within the field of the engineer, but it considers them only in relation to their distribution, utilization and control in harmony with philosophies that motivate men and shape current conceptions of right and wrong, or of justice and injustice if those terms be deemed more acceptable. Stabilization cannot be effected without utilizing the knowledge of the engineer, but neither can it be effected without utilizing more than comes within his traditional field of activity. In discussing the problem herein we shall endeavor to treat it briefly from that consolidated viewpoint. Rapid fluctuations in supply have characterized the oil industry from its beginning; yet only within the past ten years has an understanding begun to develop regarding the extent of waste—the degree of dissipation of natural resources—that attends the operation of the industry under the practices and laws which control it in the United States. The extent and regrettable consequences of those wastes, their underlying causes and the ease with which they could be prevented are not yet generally understood even within the industry. Producing TomoRRow' s Oil Today The interests detrimentally affected by these economic evils are vastly greater than the mere welfare of the oil industry. The problem involves the nation's supply of gasoline and other petroleum products at

Jan 1, 1933

DESIRABLE as it is to summarize what has been set forth in preceding chapters, the task can only be approached with great hesitation. What follows represents the personal views of the author at the moment of writing, reserving the privilege to change them on more mature reflection or in the light of further evidence. With that reservation they may be stated somewhat as follows. Education for the mineral industries falls into two categories; general education and technical vocational, using the word vocational not in its usual sense but to signify preparation for specific activities, in which sense a law school is a vocational school. Even at the beginning, as indicated in the first chapter, mineral industry education was partly general and partly technical and that relationship still persists, because technical education requires a firm basis of general education. Our general American system is to provide free public general education through the twelfth grade, or completion of high-school work, though there are already many technical vocational high schools, and even in a community where nearly all the young people are preparing for entrance to college there will be some who wish to qualify for employment at the end of the high-school course, or even on completing junior high. Our educational system, therefore, has not only to provide education for those who intend to proceed beyond the twelfth grade but also for those who, for a variety of reasons, may wish or be forced to cease full-time education at any level between the first and twelfth grades. This study has been chiefly concerned with the problem of what kind and how much technical education to provide for those who have completed the twelfth grade and who wish to make their living in the mineral industries. The obvious fact that the mineral industries employ all sorts of trained persons,

Jan 1, 1941

By J. E. Elliott

ALTHOUGH the firm in which the writer is a partner is not exactly the pioneer in the coring of rotary-drilled wells in Southern California, it has taken the lead in bringing coring to its present status. To the Shell Company of California belongs the, honor of having first used the core drill in its endeavors to locate subsurface structures west of Santa Fe Springs. Following those operations, similar work was done near Wasco in the San, Joaquin Valley. Results of the latter core drilling were successful, in that they made it possible to determine the under-ground structure. At, about the same time that the Shell Company was doing the work at Wasco, it was experimenting in the use of the core drill in connection with rotary-drilled holes. The oil sands in its dis¬covery well at Signal Hill were located by means of the rotary core drill. In 1921, in view of the trouble that the operators were having in the fields of Southern California, and particularly at Huntington Beach, R. E. Collom, of the State Mining Bureau, called their attention to the possibilities of the core drill for eliminating many of the serious problems that were facing them. It was this same difficulty encountered by the operator in locating the oil sands that caused the writer to enter into con-tract core drilling; late in 1921 the California operators became converted to the advantages of that method, and in the short space of one year core drilling in rotary-drilled holes has risen from a theory to an established practice.

Jan 10, 1923

By P. E. McKinney

Developments in engineering during the past decade, particularly as applied to marine construction, mining machinery and other purposes in which corrosion offers a serious problem, have created a large demand for a non-ferrous metal highly resistant to corrosion and at the same time useful in general construction work as a substitute for steel without materially decreasing the factor of safety or increasing the weight of the various parts over that ordinarily used in the case of mild steel. To obtain the combination of desired properties many compositions have been proposed and used with excellent success, but at the present time probably the most popular and most widely used combination is the non-ferrous alloy commonly called manganese bronze. This is nothing more than a high brass to which have been added, by the proper method of alloying, comparatively small percentages of aluminum, iron, or manganese with the definite purpose in view of strengthening the alloy and rendering it more dense and close-grained than the average yellow-brass casting. In the manufacture of manganese bronze a great deal has been said about the importance of using only the highest grades of raw material and the beneficial or detrimental effects, as the case may be, of various impurities, as well as the importance of adding the ingredients according to various formulas proposed; but in most of these cases the literature on the subject has dealt principally with the manufacture of this alloy from virgin metals and raw materials of the highest purity. It is the purpose of this paper to deal particularly with the possibilities that lie in the proper development of methods for manufacturing such an alloy by more economical methods than those which have usually been discussed in other literature on the subject. Shortages have recently existed in raw materials needed for many products entering into the various branches of engineering work, particularly the non-ferrous metals, and during the next few years of reconstruction the country will be flooded with many

Jan 1, 1919

By Edgar Trask

EACH branch of engineering seems to depend on the cooperation and contribution of some other branches to enable it to produce more efficient methods and appliances for man to use. The purpose of this paper is to show approximately the gain in efficiency of self-propelled merchant ships when steel of greater elasticity is substituted for mild steel in some of the strength members and alu-minum alloy is substituted in some of the parts where strength is not essential. The new steel will have some greater strength and a much greater elastic limit in the as-rolled condition, and must be readily weld-able under ordinary conditions of shipbuilding. Naturally, its cost may be more than mild steel, but if the demand is great that excess cost may be reduced to an amount that will make its use more economical than that of the present mild steel. There appears to be a well defined axiom in engineering today that to use the least power to carry a given load the weight of the carrier must be reduced to a minimum. This minimum must be, of course, consistent with the necessary strength, rigidity and durability and it must not be attained at an excessive cost where the fixed charges of the carrier will exceed the savings in, operating the motive power. Recent railroad equipment is a notable example of this, and in these trains alloy steels and aluminum together with less weight per horsepower of the power plant are reducing the weight of the carrier and hence the total power required for moving the paying load. Before considering the application of these metals to shipbuilding, it is well to explain some of the fundamentals of ship design.

Jan 1, 1936

By J. F. Kemp

IN submitting an additional contribution to the discussion on ore-deposits in the recent volumes of the Transactions, it is my desire to adhere closely to matters of material importance as affecting the actual processes. Judging from the discussion by Professor Van Hise, and from one or two reviews or other articles by associates of his in geological work, the impression seems to prevail that, in so far as my paper* referred to ,his masterly essay,†I was guilty of misconceptions regarding both the part attributed by him in it to the igneous rocks and the ubiquitous presence of the ground-water. I should regret extremely to be wanting in these particulars or to have misunderstood one for whose great services in this and other branches of geology no one has a higher esteem than myself. I have, however, in the most careful way, and with these points in mind, read his essay again, anti, taking it as a whole, I cannot gain any different impression of relative magnitudes than the one first received. The importance of the igneous phenomena and the restrictive influence of the processes described by " cementation " in their effect upon the ground-water, as set forth in Professor Van Hise's " Discussion " (Trans., xxxi., 292), impress me as being in very marked contrast with the same things in his first essay. If the point seems to anyone of sufficient importance, it can easily be decided by reading the originals. My paper was the result of some years of observation, reading and reflection, and was meant to be an independent contribution, controversial only in some subordinate particulars. In depicting the drama of the deposition of ores, I cannot but feel that Professor Van Rise assigned to the chorus and the scene-shifters some characters which, it seems to me, should

Jan 1, 1913

By H. M. St. John

Like every present-day manufacturer, the brass foundryman is faced with the necessity of reducing the cost of his finished product without impairing its appearance or quality. He must use every economy that the progress of art and science puts at his disposal and should also be alert to profit by any peculiarity in his own situation or the nature of his product that may give him an exceptional advantage. Much can be accomplished by the adoption of labor-saving equipment and improved methods of melting, molding and handling. Control of pouring temperature, study of defective castings and their causes, laboratory control of molding sand and core mixtures, the use of less expensive alloys, all contribute to the desired end. Assuming that the composition of the alloy is already as inexpensive as the character of the casting will permit, still further savings can be made by the intelligent purchase and utilization of the metals needed to produce the desired analysis. Functions of Secondary and Virgin Metals in Casting Brass It is no longer a general assumption among foundrymen that quality castings must be made from an "all virgin" mix. If suitable secondary metals can be obtained more cheaply it is wasteful to use any larger proportion of virgin metal than is required to produce castings of the desired properties. To follow such a course, however, imposes upon the foundryman a heavier obligation than was formerly the case, to make sure by test and inspection that his castings really are of the desired quality. So long as he used the most expensive grades of metal and his melting practice was reasonably correct he was not obliged to give much thought to the quality of the metal in the castings. If he is to use secondary metals he must, in order to retain the confidence of his customer, examine these metals very carefully before use, exercise scrupulous control over his melting and pouring conditions and examine his castings closely. These statements apply more particularly to the jobbing foundry. The foundry department in a manufacturing plant is in a somewhat

Jan 1, 1930

By Albert Hayes

FOUR mines at Wabana, on Bell Island in Concep-tion Bay, Newfoundland, produced 1,209,777 tons of ore in 1927, and it is expected that the produc-tion will be larger in 1928. The ore is a stratified oolitic hematite of sedimentary origin. Three workable beds and many thin beds occur in a thickness of 400 ft. of interbedded sandstones and shales. It is not profitable under present conditions to mine extensively in ore beds less than 4 ft. thick. The iron ore beds outcrop on the small island and are inclined northward more steeply, than the slope of the ocean bottom. The mine work-ings follow the bedded ore below the sea bottom, No. 3 Mine extending about 2 miles north of the island. At this point there is a cover of 1500 ft. of rock and 600 ft. of ocean water. It is impracticable to operate drills in the ocean to prove the extent of the submarine orebody in advance, and diamond drilling from the mine workings is the only method of exploration. Bell Island has been settled for a long time and a monument at Cupids, near Brigus at the head of Conception Bay, commemor-ates the tercentenary of a settlement there in 1611 by Captain Guy of England. was one of the chief ports of Newfoundland for deep sea fishing and doubtless many a captain wondered about the red rocks as he sailed past. The famous geologist, J. B. Jukes, records seeing a bright red sandstone 8 ft. thick on the northwest side of Bell Island during a visit in 1842, but he evident ly did not try to land on that rocky coast to get a sample. The iron ore is plainly visible in the high cliffs along the coast of the island, as bright brown layers interbedded with gray and white sandstones and dark shales. The heavy red rock was used by the fisher-men as anchor weights for fish nets and small boats, but its real value, so the story goes, was discovered by a merchant in Saint John,

Jan 8, 1928

By M. Van Siclen

THE outstanding fact in connection with dust disease in the United States at present is the growing recognition of its seriousness by state officials and by the more progressive operators of mining, metallurgical and allied industrial plants. The same may perhaps be said of labor in some of its better organized centers, but the average independent non-union workman continues, as of yore, to suffer the toll of disability and even of death from dust inhalation without realization of the source of his ill-being. Progress in the betterment of the handling of sufferers from dust disease and of the conditions creating dust hazards in mining and allied industries is pursuing a course similar to that of the now widespread campaign against accidents, in which the risk is more obvious, more severe, and was naturally recognized sooner. The coming on of dust disease is generally relatively slow and its immediate effects not infre¬quently masked by or attributed to other diseases. Marked exceptions to this general rule have occurred in districts where the dust is particularly pernicious, such as the Rand and Joplin; yet such exceptions, unhappy in themselves, opened the eyes of medical men, and of those in other localities charged with the responsibility for the welfare of industry, to the much more widespread if less spectacular hazard. existing from the inhalation of dust in all rock-excavating operations and all industrial operations creating inorganic dust, whether it be crushing and grinding, sand-blasting, granite-cutting, or what not. Advancement to date in the United States in prevention and treatment has been slow, yet the record shows that quantitative methods for determining the degree of hazard and means for decreasing it were being developed as far back as 25 years ago; and that more rapid progress may be looked for from now on. In 1908, in this country; F. L Hoffman?(1) discussed the mortality from consumption in dusty trades, especially brass foundries; and in 1913 E. R. Hayhurst(2) described the effects of inhalation

Jan 1, 1933

By Marcel R. Daly

EUGENE COSTS, Calgary, Alberta (communication to the Secretary*).¬This new theory to account for the accumulation of commercial deposits of oil and gas, is deliberately and admittedly based on the hypothesis that the origin of these products is organic. Mr. Daly says (page 1142), "Should the organic origin of the petroleum that is found in pools be granted, the following interpretation is offered for the mechanics of its accumulation." But suppose the origin thus accepted by definition be incorrect, then what becomes of the diastrophic theory, Mr. Daly's interpretation? As Mr. Daly remarks himself (same page), "It is obvious that the history of petroleum will have to be entirely different, dependent upon its origin, either from emanations coming from the depths, or from organic decomposition in the strata themselves." Then why should one propound a theory, through which he is endeavoring to trace the history of petroleum, by starting with a definition of its origin? The origin should be the deduction, the forced conclusion of the theory, and not its starting point. Facts alone should be considered first, in any theory worth the name, until sufficient proofs have accumulated to permit of the deduction of a complete explanation for these facts. This would lead one to the origin through a real theory founded on facts, and not based on a preconceived idea perhaps true, but possibly fanciful. Mr. Daly's way can only lead on one road, namely the organic road, and, I repeat, it may be the wrong road. In the case of the petroleum deposits, as .I have endeavored to show in several papers on the subject, to which the reader may refer, the facts clearly lead to the force conclusion that their origin is not one of accumulations of hydrocarbons at first disseminated in the sedimentary strata but the reverse process of subsequent local infiltrations and impregnations of hydrocarbon emanations from the depths. This new theory, therefore, founded on, an erroneous conception of origin cannot be a help in the solution of the petroleum' problem, not any more than were the anti-theory or the hydraulic theory, both of which were also based on the same error, although Mr. Daly is inclined to think that the authors of these two theories did not accept the misconception boldly enough (page 1142). -

Jan 12, 1916

By Robert W. Phelps

It is gratifying to observe the growing interest in the study of oil-well spacing. It should always be held in mind that the problem of optimum spacing is to obtain the maximum return of capital per acre drained. This naturally evolves.into a mathematical consideration. As mathematics is the basis of all science, an effort should be made to develop formulas which involve data obtainable in the early stages of development. The first information from a discovery well in a new field would be the character of the sand, rate of initial production of oil and gas, viscosity of the oil, rock pressure, etc. Later, from this well, if Herold's theories of hydraulic, volumetric and capillary controls are accepted, could he determined the ultimate production as without interference from drainage by subsequent well completions, and under which control the well is producing. If it should prove to be producing under capillary control, a rough estimate could be made of it's radius of drainage. With but one well, the radius of drainage, or the interference of drainage of individual wells by close spacing, would be estimated by comparison with similar conditions in other fields in which the development has progressed sufficiently to furnish the data. A second well that is spaced sufficiently close so that an interference can he observed after its ultimate production is estimated, will furnish data to develop a desirable spacing of wells which can be inaugurated for that area and which is capable of producing a uniform amount of oil under like conditions. In some fields this area will be extensive, in others each well location will require an individual study. In 1924, Cutlerl developed a scheme whereby he determined by tabulation a spacing of oil wells for the maximum return per acre. After a study of production in a number of fields, he developed the following as a tentative rule: "The ultimate production for wells of equal size in the same pool where there is interference (shown by a difference in the, production decline curves for different spacing) seems approximately to vary directly as the square roots of the areas drained by the wells. This rule may also he stated thus: The recovery from wells of equal size

Jan 1, 1929

By C. W. Jr. Gennet

ANNOUNCEMENT was made in the spring of 1926 that the Boston & Maine R. R. Co. had contracted with the well known German steelmakers, Messrs. Fried Krupp, for the manufacture of 15,000 tons of basic open-hearth steel rails at the Rheinhausen Works, for delivery to Boston, Mass. The manufacture of rails in the United States has for many years been almost a national pride, and as this feeling is chiefly the result of a long-time liberal and consistent patronage of, American rails by American railroads, it is not strange that this somewhat unusual announcement should arouse more than ordinary interest. Since the end of the World War, the importation of foreign rail has been fairly large, principally because the newly created economic conditions have rendered some American competition more difficult, but the tonnage imported, for the most part, has been made up of small orders for miscellaneous use; and the contract referred to constitutes the largest single importation of foreign rail in over ten years. In 1915, the Algoma Steel Co. of Sault Ste. Marie, Canada; supplied the Illinois Central R. R. with 30,000 tons of rails,1 and various other American roads with smaller amounts. In 1902, 1903 and 1904, large tonnages of rail from abroad were purchased, the Louisville & Nashville R. R. alone obtaining 30;000 tons from German mills. It is the object of this paper, to present, in what is believed to be a new and concise form, figures showing the production and consumption of rails in the United States, and to record some of the testing and inspection results of the recent Krupp rails; also, to direct attention to two quite unique departures from American practice that were regular features of the Krupp process and which are worthy, it is thought, of careful study.

Jan 1, 1928

By David Reger

Introduction THE exhaustion of oil and gas in the United States is proceeding at a rapid pace. This is especially true in fields where the light oils that furnish the most fuel for internal-combustion engines are found, leading to a late estimate by Arnold that the petroleum resources are 36 per cent. exhausted.1 The further remark by Dr. David T. Day at the New York meeting of the Institute, in February, 1916, that the operators of the country are now scarcely able to supply the ever-increasing demand for gasoline, leads the writer to believe that a determined effort will soon be made to secure deeper producing horizons in those regions that now furnish high-grade oil, and in which pump stations and pipe lines offer convenient means for the economical handling of new production. A study of Arnold's table shows further that the States that produce paraffin oil exclusively are 45 per cent. exhausted, this figure being much higher than the average of paraffin and asphalt States altogether. The most extensive of all the paraffin-oil-producing areas is the Appalachian Field, extending with the Appalachian Geo-Syncline from western New York southwestward through western Pennsylvania, western West Virginia, Ohio, Kentucky, and Tennessee, where oil of high gravity is always secured. Of these States, Pennsylvania and West Virginia rank highest in. the quality of their product. In West Virginia, the oil sands dip to a lower level than in any other locality in the Appalachian Geo-Syncline, the Pittsburgh Coal of the Pennsylvanian being only 50 ft. above sea level along the Nineveh Syncline at Wileyville, Wetzel County.2 The very significant fact that the sands of the Mississippian and Upper Devonian Measures furnished the richest oil pools of the State along this

Jan 9, 1916

By Guy Ruggles

IN this paper the authors aim to chronicle the experience and salient points brought out in changing flotation reagents at a concentrator which had probably been using a minimum amount of oil at a minimum cost per ton, to a more complicated system requiring a partial chemical control. The original oils were coal tar and pine oil. The new reagents are line, xanthate and pine oil. It was found that there were no insur-mountable difficulties and eventually the cost of the new reagents per ton of ore proved to be very little more than that of the old. LIME PLANT When the question of handling lime came up there were two propositions open: (1) to handle the lime dry; (2) to handle it wet in the form of an emulsion. Granting that a dry lime feeder would function properly, delivering lime uniformly, the chief objection was the dust that would be raised when these feeders were being charged or operated, as the only possible location was on a gallery beneath which men were working. With this objection the handling of lime as an emulsion seemed to he the better scheme. The lime plant which was first installed was for experimental work on one section. This was gradually changed and developed until it was of sufficient size to accommodate 20 sections. The various changes will not be discussed and the following description deals only with the fully developed plant. Crude as it is, and perhaps somewhat expensive to operate, the lime-handling plant has been quite successful. Much has been learned which will pave the way for a better installation in the future.

Jan 1, 1927

By Gordon C. Hicks

Prior to 1950 most fertilizer manufactured in the United States was produced in a nongranular form. In such form, the material caked when stored and was extremely dusty when applied in the field. About this time a wide interest developed in the fertilizer industry for the manufacture of a granular, high-analysis fertilizer of improved physical properties. Thus, TVA began work on fertilizer granulation about 1950 using both a pugmill (double-shaft paddle mixer) for a thick slurry of nitric phosphate and a continuous ammoniator-granulator drum for superphosphate-base mixed fertilizer. Granulation in these units was mainly by agglomeration. The liquid phase generated by the moisture and by the heat of reaction of ammonia with acidic materials, such as superphosphate and sulfuric or phosphoric acids, resulted in agglomeration of the solid ingredients. About 1956, TVA began studies of the use of a pan or disk granulator for production of ammonium nitrate or other fertilizers containing a large proportion of ammonium nitrate, such as 30-10-0 ammonium phosphate nitrate. This is the layering method of granulation. More recently, TVA has demonstrated pan granulation of urea from a highly concentrated solution and granulation of ammonium polyphosphate melts in a pugmill. The bulk of TVA studies throughout the years has related to use of the drum granulator. About 200 granulation plants in the United States have been licensed and built to use the TVA continuous ammoniator-granulator; it is estimated that more than half of the 20 million tons of mixed fertilizer used in the United States in 1974/1975 was produced in these plants. Some other granulation processes developed for use in the drum granulator include diammonium phosphate, monoammonium phosphate, urea- ammonium phosphate, ammoniated superphosphate, and most recently, NPK fertilizers by melt granulation using a pipe reactor.

Jan 1, 1977

By G. R. Mansfield

THE third year of Government exploration f or potash by the U. S. Geological Survey and-the U. S. Bureau of Mines under the authorization of the act approved June 25, 1926 (Public 424-69th Cong.) is drawing to a close. The results thus far obtained are thought to be sufficiently interesting and satisfactory to justify the presentation of a brief preliminary account of the work. REVIEW OF EARLIER EXPLORATION The general geologic similarity of the Permian basin of Texas and New Mexico to the potash field of Germany had long ago suggested the possibility of the presence of potash salts somewhere in that basin, but petroleum exploration was then making little headway there and the necessary data could not be obtained. The discovery by Udden in 1912 of potash in brine from the Spur well in Dickens County, Texas, was the first direct evidence of its presence. In 1915-17 the U. S. Geological Survey drilled a test well with standard tools at Cliff side near Amarillo, but failed to find potash. Nevertheless, an observer has been kept in the field, at first in cooperation with the Texas Bureau of Economic Geology but since 1922 by the Survey alone, to `secure data and samples from oil and gas tests. Since the discovery of oil in Reagan County in 1923 exploration by drilling has been rapidly extended to many parts of western Texas and southeastern New Mexico. The identification of the potash-bearing mineral polyhalite was first announced by the Geological Survey in June, 1921, the material having come from cuttings from the Bryant well in Midland County and the Burns well in Dawson County, Texas. Successive discoveries and announcements of similar purport aroused widespread interest in potash exploration, which culminated in the action by Congress already noted.

Jan 1, 1929

By Karl Sundberg

INTERESTING results were recently obtained in geophysical prospecting at the Questa mine of the Molybdenum Corpn. of America in New Mexico. This paper describes that survey, which was carried out during October and November, 1927, by the Swedish American Prospecting Corpn. It is hoped that the paper will make it possible for the mining man to form an opinion of the applicability of geophysical prospecting under difficult conditions, showing, as it does, the results when prospecting for small small orebodies with comparatively poor conductivity, in a region of rough topography. Some principles underlying electromagnetic prospecting not known to be published previously will also be given in an elementary way, with special attention to the general structure of the electromagnetic field. GEOLOGICAL CONDITIONS AT QUESTA The property is situated in the Taos range of the Rocky Mountains in northern New Mexico. About this region, L. C. Graton says:1 The main range is made up of pre-Cambrian granites, gneisses and schists but in the vicinity of Red River igneous rocks of later age are present almost to the exclusion of the older series. These younger rocks are divisible into two groups. The older of the two, probably pre-Tertiary age, is represented by large intrusive masses of monzonite porphyry, usually containing considerable quartz. The more recent group comprises intrusive' and probably effusive dark-colored andesites and coarse andesitic breccias, some of which contain fragments of the monzonite; there are also flows of rhyolite and beds of rhyolite breccia. The evidence regarding the relative age of the andesite and the rhyolite is not wholly satisfactory, but there is little doubt that the andesite is the older. The ore deposits, although occurring more commonly in the monzonite porphyry than in the rhyolite, nevertheless are believed to be genetically related to the rhyolite. They certainly cut the rhyolite or andesite in places, and hence fall in the late Tertiary.

Jan 1, 1928