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By K. J. Brondyke, P. D. Hess

Lack of correlation between densities of aluminum alloy samples solidified under reduced pressure (vacuum gas test) and hydrogen content of the metal is explained on the basis of inclusions serving as nuclei for hydrogen bubble formation. As a result of these findings, the vacuum gas test is suggested as a practical tool to indicate metal cleanliness and the potential effects of hydrogen. Visual obseroation of the sample during solidification under vacuum provides more useful information than that obtained either from density meas -urements or sectioning of the solidified sample. A rapid, practical method of detecting and measuring gas in molten-aluminum alloys has been sought for many years. The development of the vacuum gas test appeared to solve this problem. However, the vacuum gas test is subject to certain limitations, and the results must be interpreted mindful of these limitations, as described herein. Since the only gas which is appreciably soluble in aluminum is hydrogen, the terms gas and hydrogen will be used interchangeably in this paper. In the early days of the aluminum industry, when techniques were not as refined as they are today, it was customary to pour small "pancakes" of alumi- num on a metal plate. These were allowed to solidify under atmospheric pressure. Excessive gas in the metal was evidenced by the appearance of small bubbles on the surface of the "pancake".' It is obvious that such a method would only show very high gas levels far above any which could be tolerated by today's standards of quality required for most applications. Various attempts were made to develop methods which would be more sensitive. Among these were measurements of density of aluminum alloys solidified under controlled conditions, radiography of cast slabs, and examination of fractures. The method which showed the greatest promise and appeared most practical was the solidification of a sample of the molten aluminum alloy under vacuum. The samples so solidified are evaluated either by observation for bubble emission during solidification, by sectioning the solidified sample and examining for porosity, or by determining the density of the solidified sample. This test is known internationally as the Straube-Pfeiffer test or the reduced-pressure solidification test, but in America it is commonly referred to as the vacuum gas test2-' and will be so designated in this paper. The determination of density appeared an attractive and convenient means of providing a numerical rating for the samples. Attempts were made in some instances to correlate densities to hydrogen contents. Unfortunately, the visible loss of gas during solidification of samples with high gas contents precluded a correlation of vacuum gas test densities with the observed gas evolution. This led to Alcoa's use of two different pressures; 50 mm of

Jan 1, 1964

By G. L. Craig

In order to meet the unprecedented demand for copper it has proven necessary not only to develop every primary source, but also thoroughly to exploit the vast reservoir of metal in use that is not directly serving the war effort. To accomplish this, industry has been called upon to use its resourcefulness for developing methods of recovery that have not been previously utilized. It is in this connection that we have been asked to review the methods suggested for recovering the basic constituents of various types of the so-called clad or composite steels. As a background for a discussion of recovery processes, it seems appropriate to consider clad materials in general and their processes of manufacture. A composite steel has been defined as one consisting of two or more component parts of which the smallest shall comprise at least 3 per cent of the total mass. Clad materials or composites are produced commercially by several different methods of which the most important may be classified as: I. The Blacksmith or Forge Weld Method. This method is limited to carbon steels or low-alloy steels as the presence of even small amounts of common alloying metals prevent the formation of a satisfactory weld. The principle is the application of pressure to sections in contact at elevated temperatures. Because of the tendency of the iron to oxidize, borax is generally used as a flux to absorb the iron oxide. 2. Casting Process-In this method a composite ingot, billet or cake is produced by pouring one metal onto or about another. The bond may be accomplished by the action of the molten metal against a solid, in which case the bond may be referred to as mechanical; while in other instances alloying occurs at the interface producing an anchor by the formation of component parts of the two materials. 3. Cementation Process.-In this process any number of combinations of metallic and nonmetallic constituents which are mixed together may be used as a bonding agent. The combinations, whatever they may be, are placed between the materials to be joined and subjected to pressures at elevated temperatures to produce the desired bond. 4. Fusion Welding Processes.-Gas and electric joining for direct use or subsequent fabrication. 5. The, Assembly Process.-This method involves the joining together of prefabricated bars or plates followed by hot and/or cold working the assembly to the desired finished form. This method is advantageous in many cases because of its flexibility on small quantities as compared to the casting method. It is also possible to control the relative proportion of components more accurately. In this discussion we are concerned only with the scrap resulting from the manufacture of clad materials and our interest,

Jan 1, 1943

A SPRING meeting is to be held at Cleveland this month under the joint auspices of the Iron and Steel Committee and the Ohio Section with the cooperation of the neighboring sections in Pennsyl-vania, Illinois, and the other States of the Great Lakes region. The discussions will be focused on just one subject, that of manganese, but will cover that thor- oughly as is indicated by the following list of papers. TECHNICAL PROGRAM Some Political Aspects of the World Manganese Situa-tion. By C. K. Leith, Professor of Geology, Uni-versity of Wisconsin, Madison, Wis. Manganese Resources in Relation to Domestic Con-sumption. By J. V. W. Reynders, Consulting En-gineer, New York, N. Y. Manganese Deposits of the' Gold Coast, Africa. By Sir Arthur E. Kitson, Director of the Geological Sur-vey of the Gold Coast, London; with Notes on the Petrology of Certain Associated Manganese Silicate-bearing Rocks. By Maj. N. R. Junner. Reserves of Lake Superior Manganiferous Iron Ores. By Carl Zapffe, Manager, iron ore properties, North-ern Pacific Railway Co., Brainerd, Minn. Iron Manganese Alloys Low in Carbon. By. Sir Robert Hadfield, Hadfields, Ltd., London. Manganese in Non-ferrous Alloys. By M. G. Corson, Consulting Engineer, New York, N. Y. Importance of Manganese in the Steel Industry. By H. M. Boylston, Professor of Metallurgy, Case School of Applied Science, Cleveland, Ohio. Minnesota Manganiferous Iron Ore in Relation to the Iron and Steel Industry. By T. L. Joseph, E. P. Barnett and C. E. Wood of the North Central Min-ing, Experiment Station, U. S. Bureau of Mines, Minneapolis, Minn. Representatives of the leading steel companies, the Army, the Navy, the Geological Survey, Bureau of Mines, and leading technical societies will be present and a lively discussion of the various papers is already assured. Nearly 14 pounds of manganese is needed for every ton of steel made. Estimates indicate that the total reserves of ore in this country suitable for making ferro would hardly supply domestic requirements for ten years, even if it could all be mined in that time. The grade of ore called for by present practice must come from abroad. The present tariff policy of this country is stated to cost industry $8,000,000 in order to force production of manganese ore to the extent of $600,000. What is the wise thing to do? Should a stock be accumulated? If so, how? Is it feasible to change practice and use low-grade ore or to beneficiate the ores of this grade and meet our requirements? What progress is being made in this direction? ,These and similar questions are raised in the various papers that have been submitted and will be open for dis-cussion.

Jan 3, 1927

THE CHAIRMAN (E. G. SPILSBURY, New York, N. Y.).-The relation of the character of manganese ore to the surrounding rocks was called to my attention very strikingly in a recent investigation in Costa Rica. In the foothills of the main coastal range there is a large deposit of manganese which extends for over 150 miles along the coast. This is in a porphyry district and the occurrences are almost exclusively along the lines of contact between a recent diorite intrusion through the porphyries. Wherever that intrusion appears to have exerted great force, the line of contact is very clear between the porphyries and the diorites. Where the action has been slower and the lifting force of the intrusion more gradual, there has been a zone of fracture of very considerable width. Those ores which occur where the fractured zone has not been very extensive carry a, lower percentage of manganese than where it has been deposited along a wider zone of fracture. In the so-called narrow veins, which are really the predominant ones, the solution carrying the manganese has evidently attacked the silica in the intrusive rock, and the resulting ore is practically a combination of manganese and silica, running froth 20 to 30 per cent. of manganese and from 20 to 40 per cent. of silica: hence those ores are not likely for a long time to become a factor in our manganese supply :for this country. On the other hand, where the disturbance to the porphyritic schist has been more intense; the manganese deposits are not so extensive, but the ore is richer, running from 45 to 51 and 52 per cent. manganese, with a silica content of from 4 to 5 per cent. There seems to be some resemblance in these deposits to those of the Cuyuna range. EDMUND NEWTON, Minneapolis, Minn.-The State Bureau of Mines has been working on the problem of concentrating manganiferous iron ore for two years or more. I should consider hand sorting as the best form of treatment, because it is practised at all of the mines which ship ore for making alloys, but not, however, oil the ore that is being used for pig iron. Hand sorting, assisted by selective mining, is readily applicable to some of this ore because the gangue is practically the original rock and is easily separated. However, it is only in rather limited zones that we find clean patches of rock. Generally the silica exists as a skeleton of the original rock structure, in which the manganese has been precipitated; some of the silica may have been dissolved, but if any of the original rock remains, the silica must be eliminated by ore-dressing processes.

Jan 1, 1918

By H. Le Chatelier

An evident connection exists between chemical and calorific phenomena: the most important, of our sources of heat, the combustion of coal, is nothing else than a chemical reaction. Not satisfied with this indefinite statement, investigators have attempted to establish a more precise correlation between these two orders of phenomena, and have questioned whether there be not a necessary connection between the possibility of a chemical reaction and the algebraic sign of the quantity of heat which it would call into play (i.e., liberate or absorb). This question possesses the highest interest for metallurgical chemists. But the study of it by experimental methods only could not completely elucidate it. To arrive at a definite solution, it was necessary to appeal to a science much more general than chemistry,—namely, that of energetics, which embraces all the physical sciences. We can place absolute confidence in its conclusions, because they rest upon a proposition which can scarcely be denied, namely, the impossibility of The main facts in the history of the development o‡ this field of Triassic coals have been already set before the Institute in the papers of Mr. Oswald J. Heinrich, a former member of the Institute and the superintendent of the mines at Midlothian. † From these and other references to the field, it appears that coal was known to exist here as early as 1701; for on the 10th of May that year Colonel Byrd reported to the Colonial Council of Virginia the discovery of coal. Coal was mined from 1770 to 1780; but the amount shipped is unknown. It was much used in Richmond at this early date for gratefires. In 1789 shipments were made to northern ports. During the first half of the century just passed, mining operations attained in this field their greatest development, the number and extent of the collieries and the tonnage of coal raised per annum being greater for that period than for any similar period since. The maximum annual output exceeded 100,000 tons, while in two years only since the Civil War has the amount of coal raised exceeded 50,000 tons. This field covers about 150 sq. in. Its outline and the position of the strata in which the coal-outcrops occur are shown on the accompanying map, reproduced from the latest survey by the U. S. Geological Survey. Mining has been carried on along the margins of the area, often in the primitive manner in vogue at the beginning of operations, by means of shafts and slopes, usually too small in cross-section to permit the proper working of the beds. Most of the output has been won from

Jan 1, 1902

By S. Gilbert, G. R. Bailey

A further evaluation of the bomb-sampling method for determining the oxygen content of liquid steel is presented. The results of this study and their close agreement with the results of an earlier evaluation confirm the conclusion that the bomb-sampling method is valid for obtaining representative samples for the determination of the oxygen content of a liquid steel bath. WHAT constitutes the most desirable procedure for obtaining a sample suitable for determining the oxygen content of a liquid steel bath has been a controversial subject for several years. In 1952 Huff, Bailey, and Richards' described a modification of the bomb-sampling technique originated by McCutcheon and Rautio.' In both the modified and original techniques, a small cast-iron or steel mold containing aluminum wire and appropriately covered is inserted into the furnace, coated with slag, and then plunged into the metal bath. Upon entering the metal, the cover melts and a sample of the steel bath enters the mold. The data presented by Huff, Bailey, and Richards' indicated that reproducible samples could be obtained by their method. Furthermore, the oxygen analyses from samples obtained by their method agreed better with those from controlled laboratory experiments than did analyses from samples obtained by methods previously suggested for sampling large liquid-metal baths. Most techniques, other than bomb-sampling, require that a sample of liquid steel be removed from the furnace in a well slagged spoon and poured into an iron mold containing aluminum or into a massive copper mold for rapid chilling. Pouring in this manner requires that the sample pass through the air. The controversy, then, is somewhat as follows: Proponents of the spoon-sampling method and similar dip-and-pour methods feel that the introduction of a cold steel mold into a molten steel bath may result in a localized boiling condition that may deplete the steel of oxygen to a significant degree in the area where the bomb is introduced. Conceivably this boil could cause results that are, on the average, too low and nonrepresentative of the bath composition. On the other hand, samples that are spooned and then poured through the air may also be nonrepresentative because of oxidation by the atmosphere. The restrictions imposed in sampling with a spoon are much more stringent than those imposed when sampling with the bomb-type mold within the furnace. The spoon sample must be taken in a well slagged spoon, a requirement that depends on the condition of the slag in the furnace. Also, the samples must be poured as quickly as possible, without shaking the spoon and without allowing slag to enter the mold. The necessity of fulfill-

Jan 1, 1955

By Donald M. Liddell

From a commercial standpoint, the only beryllium mineral warranting attention is beryl, 3Be.Al2O3.6SiO2, which is of fairly widespread occurrence. The chief deposits are in Brazil, Argentina, India, Canada and Portugal. When pure this contains about 14 per cent of beryllium oxide. The mineral richest in beryllium is phenacite, (BeO)2SiO2, or beryllium orth-osilicate, which contains 45.55 per cent beryllium oxide when pure, and if anyone is ever fortunate enough to discover a large deposit of it, it will revolutionize beryllium metallurgy. Gadoljnite, zBe0.Fe0.2Yz0~.zSi0~, is also often referred to as a beryllium mineral, though the occurrences are comparatively scant and it is of more interest as a source of yttrium than it is of beryllium. There has been a good deal of talk recently regarding some occurrences of helvite in the United States. Helvite is a complex manganese-iron beryllium silicate and, apart from difficulties that would arise in its treatment because of its compo-sition, the beryllium content of the known deposits is not high. Early Metallurgy The elemcnt beryllium was first isolated by L. N. Vauquelin in 1797.~ He crushed and heated beryl, having the idea that this heating made it more readily amenable to attack by chemicals, and then mixed the mineral with three times its weight of caustic potash and fused the mixture. The melt after cooling was dissolved in hydrochloric acid: dehydrated, and again taken up with hydrochloric acid and filtered to separate the silica. The filtrate was treated with an excess of potassium carbonate and the precipitate after draining was leached with a solution of caustic potash, which dissolved the alumina. The undissolved material was, in Vauquelin's own words, "une terre nouvelle." He dissolved the precipitate with nitric acid and evaporated it to dryness, took up with hydrochloric acid and threw the iron out with potassium hydrosulphide, though he found that to make a complete separation of the iron involved a second treatment. The solution, after throwing out of the iron, had a pronounced sweet taste, and though Vauquelin always speaks of working on "terre du beril" he suggests that the new element should be known as "glucine" (glucinum) from the Greek word for sweet, because of this outstanding property. Vauquelin did considerable work on the comparison of aluminum and beryllium, working out a separation of most of the aluminum based on its precipitation as alum. His work is reviewed at some length, since ordinarily his procedure is incorrectly stated. It will also be recognized by those who have studied beryllium metallurgy that a good many technicians have followed his ideas since, including preheating the beryl before treatment. The fusion with

Jan 1, 1944

Engineers who are in charge of industrial operations, and their number is legion, sense as much as anyone the present feeling of unrest in the' country and more than anyone else realize the present inefficiency of labor. Undoubtedly the two phenomena are closely correlated and no doubt are due to a multitude of causes which it will be impossible to enumerate. From my experience in mining I estimate that the present efficiency of labor is only about two-thirds of what it was under pre-war conditions. In the mining industry, at least, we have not a large surplus of men looking for work and usually under these conditions men are rather more independent and will not work as efficiently and faithfully as if they felt there were plenty of men ready to take their places. Wages in metal mining have advanced more than the increased cost of normal and sane living. The result is that the men often work fewer days in a month and do not seem to have very much interest in their work while actually engaged in it. Then again, they have been listening to the more or less vague propaganda of the I. W. W. and the radical wing of the socialists, who are harping on the fact that the distribution of newly created wealth is unfair and that the laborer really is not working for himself or his fellow laborers but is carrying on his exertions for the benefit of a small and lim-ited class of exploiters. A continued harping on this view is bound to influence the judgment of even a conservative workman who is not a student of economics and who hears little or nothing upon the other side. I am a great believer in the common sense of the American people and in the long run I do not think that they will be carried away by unsafe doctrines. The trouble with so many of these propagandists of industrial in-equality is that they do not differentiate between production and dis-tribution. Even if we admit that distribution is unfair, unless goods are produced there will be nothing to distribute. A great many unthinking people seem to feel that wages are paid out of a pot which is inexhaustible and do not realize that eventually what comes out of the pot can never exceed what is put into it. The workman is not paid in money but is paid in goods, money as we all know being used simply as a measure of value and a medium of exchange, and that all that can be used to pay the laborer is what he produces.

Jan 11, 1919

By Lewis W. MacNaughton, F. L. Burchard

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Coolie, Foard, Hardeman, Knox, Montague, Wichita, and Wilbarger. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, are usually modified by stratigraphic changes in the sediments. Excepting the fields in southeastern Baylor, southern Archer, and southwestern Clay Counties, all the fields within the district are on this Red River uplift. These exceptions, which have the same type of oil and gas accumulation as the other fields, are on the extreme north end of the Bend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas to Archer County. The larger part of past oil and gas production has come from Pennsylvanian strata, with less important amounts from the Permian, and minor but increasingly important quantities from the Ordovician. DevELopments during 1941 Nearly 1600 wells were drilled in the district during 1941 as compared with more than 1700 in 1940. However, the ratio of successful drilling operations was higher and some 1200 oil wells were completed. Production held about even with the previous year, as did the number of producing oil wells. Known oil reserves increased slightly throughout exploration, which generally was carried on at greater depths than in former years. The average depth of discovery wells was 300 ft. deeper than in 1940. Although discoveries were evenly divided numerically between horizons above the base of the Strawn series and those below the Strawn, the deeper horizons, including the Bend series of the Pennsylvanian, the Mississippian limestone, and the Simpson and Ellenburger of the Ordovician, furnished most of the increase in oil reserves. The largest single addition to the reserves was in the Ellenburger formation in the K.M.A. field. During the year 112 wells were completed in this horizon, bringing the total developed acreage to some 4600 acres. The Straan series in K.M.A. also received considerable development in 1941, with 114 completions. K.M.A. Pressure Maintenance Satisfactory progress was made by the K.M.A. Pressure Maintenance Association in 1941. At the end of the year, 99 wells were being used for input and total monthly volume of gas returned to the reservoir reached a high of 340,548 M cu. ft. in December from a low of 208,853 M cu. ft. in February. Total volume of gas returned during 1941 was 3,306,052 M cu. ft. To the end of the year, 150 cu. ft. of gas had been returned for every barrel of oil produced from the reservoir while the input ratio for December was 397 cu. ft. Per

Jan 1, 1942

By F. L. Burchard, Lewis W. MacNaughton

The North Texas district, as herein defined, includes the counties of Archer, Baylor, Clay, Coolie, Foard, Hardeman, Knox, Montague, Wichita, and Wilbarger. This area covers generally the crest and south flank of a system of buried mountains known as the Red River uplift. The oil and gas accumulations along this feature are in traps, which, although localized by structures incident to the regional uplift, are usually modified by stratigraphic changes in the sediments. Excepting the fields in southeastern Baylor, southern Archer, and southwestern Clay Counties, all the fields within the district are on this Red River uplift. These exceptions, which have the same type of oil and gas accumulation as the other fields, are on the extreme north end of the Bend arch, which is a broad anticline plunging northward from the Llano uplift in central Texas to Archer County. The larger part of past oil and gas production has come from Pennsylvanian strata, with less important amounts from the Permian, and minor but increasingly important quantities from the Ordovician. DevELopments during 1941 Nearly 1600 wells were drilled in the district during 1941 as compared with more than 1700 in 1940. However, the ratio of successful drilling operations was higher and some 1200 oil wells were completed. Production held about even with the previous year, as did the number of producing oil wells. Known oil reserves increased slightly throughout exploration, which generally was carried on at greater depths than in former years. The average depth of discovery wells was 300 ft. deeper than in 1940. Although discoveries were evenly divided numerically between horizons above the base of the Strawn series and those below the Strawn, the deeper horizons, including the Bend series of the Pennsylvanian, the Mississippian limestone, and the Simpson and Ellenburger of the Ordovician, furnished most of the increase in oil reserves. The largest single addition to the reserves was in the Ellenburger formation in the K.M.A. field. During the year 112 wells were completed in this horizon, bringing the total developed acreage to some 4600 acres. The Straan series in K.M.A. also received considerable development in 1941, with 114 completions. K.M.A. Pressure Maintenance Satisfactory progress was made by the K.M.A. Pressure Maintenance Association in 1941. At the end of the year, 99 wells were being used for input and total monthly volume of gas returned to the reservoir reached a high of 340,548 M cu. ft. in December from a low of 208,853 M cu. ft. in February. Total volume of gas returned during 1941 was 3,306,052 M cu. ft. To the end of the year, 150 cu. ft. of gas had been returned for every barrel of oil produced from the reservoir while the input ratio for December was 397 cu. ft. Per

Jan 1, 1942

By Glenn C. Waterman

THE diamond drill is a very important tool in exploration and development testing and its use is increasing. In almost all cases results of diamond drilling are analyzed on the basis of grade and tons. A proper evaluation of core and sludge assays is important if drilling results are to be acceptable as a basis for geologic and engineering appraisal. The relatively wide variation in assay averages as calculated by various well-known combining methods indicates that the engineering choice of a method may affect the outcome of the drilling in terms of ore and waste. The problem of combining assay results from core and sludge samples has been discussed many times in conference and in the literature.'-' Most writers agree that the field of disagreement in methods is large and that the engineer on the job must consider features unique to his drilling, pick one of several combining methods, and depart from the rules when abnormal results come in. All the discussion to date can be summed up by the admission that as yet there is no fairly simple, generally acceptable combining method that is practicable over a wide range of drilling conditions, ground conditions, and ore occurrence. The combining problem is important in evaluating drilling results at Chuquicamata. Recently a reappraisal has been made of recovery variables and their effect on assays, with the result that a new combining method is offered which fits average drilling conditions and is mathematically reasonable. It is simple in application, fundamentally correct, and an improvement over most combining methods. At Chuquicamata diamond drillholes are used to outline the grade and position of blocks of normal and marginal grade oxide, mixed, and sulphide ore. Most holes penetrate all classes of material (and waste), and it is important for mining programs as well as ore reserves to know almost precisely the soluble and insoluble copper content of mineralized ground. At present three classes of ore are mined and treated differently. For an orderly sequence of mining operations which can provide regular daily tonnages of all three ore types and keep grade at certain levels with minimum variation, ore type and its grade must be predicted. Diamond drilling plus geologic mapping and bench sampling are tools for prediction. And drilling data are largely used to calculate grade of material more than a few meters away from bench faces. The orebody at Chuquicamata" is criss-crossed by millions of barren or mineralized weak to fairly strong slips and fault fissures. Mineralization is diverse and encompasses many quartz and oxide or sulphide-bearing copper veins, as well as seams and disseminated grains. Copper occurs in oxide or sulphide minerals or mixtures of these two mineral types. Rock conditions vary from intensely seri-citized (soft and porous) through clay-altered ground to almost fresh granodiorite. The result is an orebody which offers many obstacles to good and consistent core recovery in diamond drilling. Recovery varies considerably in the several alteration zones, the various types of oxide and sulphide ores, and the position and inclination of the drillhole within the complex fracture pattern. As core recovery drops sludge samples must be used with core samples to calculate grade. Many years of drilling at Chuquicamata indicate that in good grade oxide zones and in the sulphide areas core recovery is good and the ground uniformly mineralized. Moderate loss of core, therefore, does not markedly affect grade calculations based on core assays. An early core-sludge combining method used core assays at face value as indicating grade down to 50 pct core recovery, but below this recovery percentage sludge samples were used and weighted according to the standard Longyear chart. This method apparently did not introduce serious errors, but it abruptly used sludge assays with high weighting factors representing 100 pct return irrespective of actual percentage of sludge recovered. Recent drilling activities have been directed toward outlining the marginal ore areas. The non-uniform mineralization and generally poorer core recovery in such ground indicated that a more exact core-sludge combining method was required to equate wide differences between core and sludge assays and recovery. In fringe ore areas at Chuquicamata core recovery averages about 50 pct, from a minimum of 10 to 15 pct to a maximum of 100 pct. Sludge recovery is likewise variable and averages perhaps 80 pct even though holes are cemented as water return falls off. In a homogeneously mineralized area cut by many slips and faults, with hard and soft ribs, loss of core is loss of ground which has a grade similar to that of core recovered, and core assays approximate true grade. In this case sludge samples need not be used. However, it would be unusual to know beforehand that an area is uniformly mineralized, and in fact this condition is probably uncommon. Generally the distribution of valuable minerals in the ground does not exactly compare with their recoverability in core. Thus, in the usual case, loss of core decreases the

Jan 1, 1956

By Eric Kula, Åke Josefsson

L. J. Dijkstra and R. Sladek, (Ontario Research Foundation, Toronto, and Institute for the Study of Metals, Chicago, respectively)—This interesting paper confirms some results obtained some years ago in collaboration with Fast: namely the broadening of the nitrogen peak by the presence of small amounts of manganese. Later on a more extensive study of this effect was made at the Institute for the Study of Metals at Chicago. As the work has not yet been submitted for publication we wish to mention here briefly some of the results. The effect of about 0.5 atomic pct manganese, chromium, molybdenum, or vanadium on the nitrogen-peak in iron was examined. The broadening found previously in the case of manganese was even found to be more pronounced for chromium. In the case of molybdenum and vanadium a double peak was observed which seemed to justify the idea that in all cases mainly two relaxation times were involved: namely, the normal relaxation time as found in pure iron and a second relaxation time related to the existence of abnormal interstitial lattice sites introduced by the foreign metallic element. The analysis showed that for the normal nitrogen-peak as a reference at 22°C the abnormal peak was found at about 32°, 47°, 75°, and 87°C in the case of manganese, chromium, molybdenum, and vanadium, respestively. In the manganese alloy the free energy difference for a nitrogen-atom at an abnormal and a normal lattice site was estimated at 2800 cal per mol. This means that for temperatures above 100°C the solid solubility and overall diffusion rate of nitrogen is not much affected by additions of 0.5 pct Mn. We believe that the difference in rate of precipitation of nitrogen in pure iron and the manganese alloy is mainly a question of the number of potential nuclei available in the different steels. In studying the effect of these alloying elements on precipitation of nitrogen, a distinction must be made between the para reaction and ortho reaction, using terminology introduced by Hultgren.7 The ortho reaction in which the alloying metallic element participates in the diffusion under formation of nitrides occurs at high temperatures such as 600°C. The para reaction in which the alloying metallic element does not diffuse and in which the nitride inherits its alloy content from the matrix occurs at lower temperatures. To prevent the ortho reaction the alloys have to be quenched rapidly from the phase. It is not surprising that the authors find that the height of the peak indicates a lower nitrogen content than chemical analysis. In the first place the peak is not a single relaxation peak and secondly, the steels were not quenched from the phase after the nitrogen was introduced at 580 °C.

Jan 1, 1953

By W. H. Gunniss

When the copper smelters were built, in Montana, all of the refractory products which were used in their construction were shipped in from Eastern factories. It was apparent that if a material suitable for the manufacture of these products could be found within the State, a saving of freight could be effected and a new industry built up. Prospecting for such materials was started and experiments were made with samples from numerous deposits. Considerable effort and funds were expended in an attempt to manufacture silica brick from Dillon quartz, a light colored sandstone that is found near Dillon, Mont., on the Oregon Shortline railroad. As a brick material the Dillon quartz was a failure, but it has proved very satisfactory as a silica cement. It is now being used in laying silica brick and for reverberatory furnace bottoms. A bed of quartzite that is particularly suited to the manufacture of high-grade silica brick was finally discovered at Browns Spur, 6 miles west of Anaconda. The material from this deposit is now being used in the manufacture of the Anaconda silica brick, which have gained a wide reputation for heat-resisting and lasting qualities. The analysis of an average sample of this quartz is: SiO2, 96.7; Fe2O3, 0.3; Al208, 2.5; CaO, 0.3 per cent. The very low percentage of fluxing ingredients makes this a most refractory material. All of the Anaconda silica brick are hand molded. Various types of brick machines have been tried, but the hand-mold process proved the best suited to the manufacture of silica brick from this material. The silica is first put through a jaw crusher and is then dumped into wet pans, where 4 per cent. of lime paste is added, to produce a bond. Without the lime the material would not be plastic enough to mold. After a few minutes' grinding in the wet pans the material is conveyed to the molder, who forces it into the molds by hand. The brick are then dumped on pallets and placed in the drier, where they are left. until dry enough to be set in the kilns. Some of the brick are re-pressed before being dried. They are burned about five days, in round down-draft kilns. It is not necessary to have as much heat in the kilns as the brick will be subjected to when in use in the furnaces. Montana refractories are used in smelters throughout the West. Prospecting for fire clays was also carried on. After experimenting with clays from several different deposits, it was found that a mixture of

Jan 1, 1914

By Simon D. Strauss

INTRODUCTION The changes in ownership, management, and operation of the non-fuel minerals industry since the Second World War have been dramatic. World-leading enterprises have lost their identity; host countries have taken over operations from multi-national firms; marketing practices have been drastically altered - and yet the world industry is supplying minerals on a scale far greater than had been anticipated in projections made at mid-century. The world's known mineral resources have been enormously expanded, despite the doom sayers who for decades have been predicting that depletion of non-renewable resources would impose limits to growth. PALEY REPORT One can set the stage by reviewing how the minerals outlook was regarded in a thoughtful and comprehensive analysis made in the years 1950 and 1951. During the War years, President Harry Truman of the United States had come to appreciate the decisive role played by minerals resources through his chairmanship as a U.S Senator of a committee that investigated the procurement and allocation of natural resources. In 1950, in the Cold War era that resulted in actual military conflict in Korea, he appointed a prestigious five-man commission to study the problems of Materials Policy over the following quarter century. Their findings, published in five impressive volumes in early 1952, became known as the Paley report. The text was prepared by expert scientists and economists who spent 18 months assembling statistics, making projections of future demand, and interviewing leaders in industry, academia, and government. [ ] The Commission had correctly foreseen that aluminum would replace copper as the largest volume non-ferrous metal, but it had fallen short of reality by a wide margin indeed for all three materials. Even though the Commission's expectations for growth proved to be extremely understated, it had concluded its report with grave foreboding about the effect of its estimates of demand in relation to supply, as follows: "Consumption of almost all materials is expanding at compound rates and is thus pressing harder and harder against resources which, whatever else they may be doing, are not similarly expanding. This materials problem is thus not the kind of 'shortage' problem, local and transient, which in the past has found its solution in price changes which have brought supply and demand back into balance. The terms of the materials problem we face today are larger and more pervasive." With respect to some minerals, the Paley Report expressed scepticism that, in fact, supplies would be forthcoming regardless of price. Because the Paley demand forecasts understated the actual growth in demand for virtually every mineral, one could logically have expected frequent and protracted shortages in the years since 1950.

Jan 1, 1985

By Walter Miller

Although confident of its ability to meet any demands that may be made, the petroleum-refining industry is not complacent about the situation and realizes that the quantities of petroleum products to be furnished are so enormous and so far beyond what was previously estimated that the full cooperative effort of the industry must be exerted. Establishment by the President in May of the Office of Petroleum Coordinator for Defense with Secretary of the Interior Ickes at its head, plus the formation of the Petroleum Industry Council for Defense, in November, provide the channels for united endeavor within the industry and the means for gearing that endeavor in full harmony with the nation's needs. Great strides have been made and a rapid understanding of the situation and the magnitude of the task is being attained by all concerned. Refining, by constant study and development, by willingness to experiment and install new processes, and to replace older plants with more efficient equipment, had kept on a high plane of efficiency and progress. Working under the free competitive system, it built up its establishments until, as expressed in last year's report, it was easily able to supply any domestic demand that might be placed on it. Turning the United States into the arsenal not only of itself but of the united nations resisting aggression, however, in- creased the call for practically all petroleum products and in particular 100-octane aviation gasoline and high-viscosity aviation lubricating oils. Refining Capacity With over four million barrels a day of crude oil being charged to stills at the year's end, oil refining had broken all records and faced the necessity of further increasing its size to supply the ever-increasing demand for products, some of which, like 100-octane aviation gasoline, were research laboratory curiosities a few years ago. Although the refining capacity of the United States is listed at 4,860,000 bbl., about 800,000 bbl. of this is economically unavailable because of plant location or type. To meet the increasing needs, additional capacity of another half million barrels may have to be built in suitable locations and designed with an eye toward maximum production of aviation gasoline but with inherent flexibility to make it possible to vary and interchange with production of motor gasoline, furnace oils, and other products as necessity dictates. An interesting side light on this refining capacity question was an enquiry from official Washington for knowledge as to any idle refineries of something of the order of 10,000-bbl. daily crude capacity that might be purchased for bodily removal to Russia. 100-Octane Aviation Gasoline Largest of the tasks confronting refiners at the year's end was that of raising

Jan 1, 1942

By Walter Miller

Although confident of its ability to meet any demands that may be made, the petroleum-refining industry is not complacent about the situation and realizes that the quantities of petroleum products to be furnished are so enormous and so far beyond what was previously estimated that the full cooperative effort of the industry must be exerted. Establishment by the President in May of the Office of Petroleum Coordinator for Defense with Secretary of the Interior Ickes at its head, plus the formation of the Petroleum Industry Council for Defense, in November, provide the channels for united endeavor within the industry and the means for gearing that endeavor in full harmony with the nation's needs. Great strides have been made and a rapid understanding of the situation and the magnitude of the task is being attained by all concerned. Refining, by constant study and development, by willingness to experiment and install new processes, and to replace older plants with more efficient equipment, had kept on a high plane of efficiency and progress. Working under the free competitive system, it built up its establishments until, as expressed in last year's report, it was easily able to supply any domestic demand that might be placed on it. Turning the United States into the arsenal not only of itself but of the united nations resisting aggression, however, in- creased the call for practically all petroleum products and in particular 100-octane aviation gasoline and high-viscosity aviation lubricating oils. Refining Capacity With over four million barrels a day of crude oil being charged to stills at the year's end, oil refining had broken all records and faced the necessity of further increasing its size to supply the ever-increasing demand for products, some of which, like 100-octane aviation gasoline, were research laboratory curiosities a few years ago. Although the refining capacity of the United States is listed at 4,860,000 bbl., about 800,000 bbl. of this is economically unavailable because of plant location or type. To meet the increasing needs, additional capacity of another half million barrels may have to be built in suitable locations and designed with an eye toward maximum production of aviation gasoline but with inherent flexibility to make it possible to vary and interchange with production of motor gasoline, furnace oils, and other products as necessity dictates. An interesting side light on this refining capacity question was an enquiry from official Washington for knowledge as to any idle refineries of something of the order of 10,000-bbl. daily crude capacity that might be purchased for bodily removal to Russia. 100-Octane Aviation Gasoline Largest of the tasks confronting refiners at the year's end was that of raising

Jan 1, 1942

By E. C. Babson

In order to explore the possibility of predicting reservoir performance from laboratory data, behavior of a hypothetical low-permeability reservoir has been estimated by applying data and methods currently available in the literature. A method of calculating decline in productivity index is discussed, and recoveries by internal gas drive, external gas drive and water drive are estimated. Introduction During the life of a producing oil property an operator is faced with many perplexing problems. Any attempt to determine proper well spacing, optimum rate of production, or the desirability of pressure maintenance requires the evaluation not only of a host of economic and practical operating factors but also of the future performance of the reservoir. Although in some cases economic or operating con-siderations may be of primary importance in planning a development or production program, the anticipated effect on ultimate recovery is more likely to be the decisive factor. The soundest basis for evaluating reservoir performance is past experience with oil fields, but pertinent data are difficult to obtain or apply under conditions normally encountered in California fields. Many of these fields are characterized by thick sections of alternating sands and shales complicated by faulting and rapidly changing lithologic conditions. Further compli- cations are introduced by haphazard development and production practices resulting from competitive conditions, changing demand for oil, and insufficient knowledge of structural conditions during early development. Even in the rare cases where development has been systematic and adequate, production policy has usually been controlled by economic and competitive factors rather than a desire to obtain information for use in future operations. In other words, comparable reservoirs in which development and production practices have been systematically varied are seldom found. In the light of these conditions, conclusions based on experiences usually lack the certainty required for decisions involving large sums of money. Some other method of attacking these problems is needed to supplement and orient field experience. Progress in laboratory investigations of the flow of oil, gas, and water through sands has been so rapid in recent years that these data may furnish such a supplementary approach in the near future. In order to explore this possibility the author has attempted to predict the behavior of one type of reservoir by applying published data and methods. Basic Data and Assumptions Calculations outlined in this paper are dependent upon a detailed knowledge of the properties of oil, gas, and water present in the reservoir and the portion of the total pore space originally filled by each. It is also necessary to know how the permeability of the sand to oil, gas, and water varies with the saturations of these fluids 20

Jan 1, 1944

By E. C. Babson

In order to explore the possibility of predicting reservoir performance from laboratory data, behavior of a hypothetical low-permeability reservoir has been estimated by applying data and methods currently available in the literature. A method of calculating decline in productivity index is discussed, and recoveries by internal gas drive, external gas drive and water drive are estimated. Introduction During the life of a producing oil property an operator is faced with many perplexing problems. Any attempt to determine proper well spacing, optimum rate of production, or the desirability of pressure maintenance requires the evaluation not only of a host of economic and practical operating factors but also of the future performance of the reservoir. Although in some cases economic or operating con-siderations may be of primary importance in planning a development or production program, the anticipated effect on ultimate recovery is more likely to be the decisive factor. The soundest basis for evaluating reservoir performance is past experience with oil fields, but pertinent data are difficult to obtain or apply under conditions normally encountered in California fields. Many of these fields are characterized by thick sections of alternating sands and shales complicated by faulting and rapidly changing lithologic conditions. Further compli- cations are introduced by haphazard development and production practices resulting from competitive conditions, changing demand for oil, and insufficient knowledge of structural conditions during early development. Even in the rare cases where development has been systematic and adequate, production policy has usually been controlled by economic and competitive factors rather than a desire to obtain information for use in future operations. In other words, comparable reservoirs in which development and production practices have been systematically varied are seldom found. In the light of these conditions, conclusions based on experiences usually lack the certainty required for decisions involving large sums of money. Some other method of attacking these problems is needed to supplement and orient field experience. Progress in laboratory investigations of the flow of oil, gas, and water through sands has been so rapid in recent years that these data may furnish such a supplementary approach in the near future. In order to explore this possibility the author has attempted to predict the behavior of one type of reservoir by applying published data and methods. Basic Data and Assumptions Calculations outlined in this paper are dependent upon a detailed knowledge of the properties of oil, gas, and water present in the reservoir and the portion of the total pore space originally filled by each. It is also necessary to know how the permeability of the sand to oil, gas, and water varies with the saturations of these fluids 20

Jan 1, 1944

By John Chipman, Karl L. Fetters

Tax relationship between the composition of the slag and that of the underlying metal during the refining of a heat of liquid steel may best be studied in the light of the two broad physicochemical concepts of equilibrium and reaction rate. Actual steelmaking processes, typified by basic open-hearth practice, involve such complexities of operating variables that it is impossible to distinguish with any degree of certainty between the general limiting conditions imposed by chemical equilibrium and the effects associated with rates of diffusion or of chemical reaction. Further advances in the physical chemistry of steelmaking will depend upon our ability to distinguish clearly between these two kinds of effects, and the experimental work that must be done falls naturally into two classifications. The first is the study of chemical equilibrium that cannot be carried out with assurance under operating conditions but must be done in the laboratory. The second is the subject of rates of reaction and diffusion and the mechanism of the process as a whole, which can best be studied under operating conditions. The latter is not entirely independent of the former, since its interpretation often requires a knowledge of the equilibrium state. It is the purpose of this and of several papers that will follow to present the results of laboratory investigations of equilibria involving liquid steel and slag. Open-hearth slag is a complex mixture containing at least eight major components and perhaps twice as many whose influence may be classified as probably minor. It is not surprising that progress toward a complete understanding of such a material at high temperatures has been slow. Attempts to apply the established principles of physical chemistry to the behavior of the individual components of this mixture have been beset by an almost complete lack of data on its chemical properties in the liquid state. This has necessitated the adoption of various methods of approximation based upon such assumptions as, for example, that for a given component the ratio of its mol fraction in the slag to that in the metal is a constant, or that the molecular composition of the liquid slag is the same as its crystalline constitution after solidification. From the thermodynamic viewpoint, such assumptions are merely useful dodges, which enable one to hazard a guess as to the magnitude of the more fundamental quantities, the chemical potentials and activities of the components of slag. The problem of determining the activity of each substance in an eight-component system seems too complex to be undertaken without the aid of generalizations derived from experimental data on similar systems containing a smaller number of components. Accordingly, it was planned in the present investigation to study the equilibrium of molten iron with the simplest

Jan 1, 1941

By W. A. Clark, E. H. Dresser

ORE from the Minnesota iron ranges is transported from the mines to the loading docks on Lake Superior over four different railways: the Great Northern, Northern Pacific, Soo Line, and Duluth, Missabe and Iron Range, with hauls varying from 60 to 110 miles. For this service a large amount of specialized equipment is used. The steel ore cars are of the hopper type, 24 ft. long, to dump into alternate pockets of the docks, these pockets being 12 ft. long to correspond with the 12 or 24-ft. spacing of the boat hatches. The more recently con-

Jan 1, 1941