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By Basil B. Zavoico

During 1937 the Russian oil industry made very satisfactory progress in its exploration branch and added considerably to its proven reserves in the older producing districts, while several entirely new potential areas were opened for development by discovery wildcats. The exploitation of known fields, however, suffered greatly from internal political difficulties, referred to as "sabotage," and was also seriously handicapped by the requirements for national defense under the duress of a grave international situation. More particularly, the necessity for preparing for a major war resulted during 1937 in short-rationing of the oil industry in its iron, steel and rubber requirements, affecting quantitatively drill pipe, casing, tubing and the rubber equipment of automobiles, and qualitatively much of the oil-field machinery for which it was either impossible or difficult to obtain iron or steel of required specifications, which necessitated manufacture of heavier and unwieldy equipment and caused directly and indirectly an unavoidable major curtailment of drilling operations below the planned footage. War-preparation measures during 1937 also required accumulation of a large gasoline reserve in the Vladivostok area and inasmuch as shipments from California can be made much more cheaply than from Caucasian refineries, either by tank cars across Siberia or by tankers via Suez Canal and Indian Ocean, some 2,000,000 bbl. of gasoline was imported from the United States in the past year, resulting in a decline of 46.98 per cent in net exports of all petroleum products from Russia below the 1936 net export volume, which is the lowest level since 1925. Production of crude oil during 1937 is estimated at 212,742,000 bbl. as compared with 202,543,700 bbl. produced in 1936, an increase of 5.04 per cent, but 11 per cent below the planned output. There were no major readjustments as to the source of crude-oil production, Baku district still accounting for the largest share; that, is, 77.21 per cent of the total. Exploration operations were outstandingly successful during the past year, major discoveries having been made on the Apsheron Peninsula, in Grozny and Maikop-Kuban districts, in Ural-Permian Basin, in Middle Volga-Samara district and other areas.

Jan 1, 1938

By George Wendell

THE fact that a symposium on pyrometry is being held under the auspices of the American Institute of Mining and Metallurgical Engineers may very properly be taken as a recognition of the importance of temperature measurements and control in production and in the industries, and of the need for instruction in pyrometry in our schools of engineering. Though there may be general agreement as to the need of some instruction along this line, there will undoubtedly be divergence of opinion as to the amount of time that can be allowed to such instruction, as well as to its character. Those who have given little attention to the complexity of high-temperature measurements will be apt to think that a few simple experiments are all that is required. They fail to distinguish between the artisan, who merely has to learn how to use any piece of apparatus that is installed, and the technically trained man, who must be prepared to assume the responsibility for the supervision and maintenance of the pyrometric equipment, for the calibration of the instruments, and for the solution of any temperature problems that arise. In approaching this subject two questions present themselves: What should be the character of the instruction in pyrometry in an engineering school, and what can be expected of the students who have had this instruction? In brief, it may be said that the aims of a course in pyrometry should be to give: (1) A thorough grounding in the fundamental principles of thermoelectric, resistance, radiation, and optical pyrometry, and of liquid and gas thermometry; (2) practical instruction in the calibration of pyrometers; (3) acquaintance with the errors that are likely to arise and the precautions that must be observed in practice; (4) information regarding the limitations of the various classes of instruments, their relative reliability, and the accuracy attainable with them at different temperatures; (5) acquaintance with the commercial instruments on the market, their construction and relative merits; (6) a knowledge of the chief sources of information relating to the measurement of high and low temperatures. To sum up, the aim should be to turn out resourceful young men familiar with the leading instruments on the

Jan 9, 1919

By F. J. Tuck

THE Hayden mill of the Ray Mines Division, Kennecott Copper Corporation, is now equipped with two 9 by 12-ft. rod mills having a daily capacity of 6000 tons of coarse-crushing plant product from the mine. These two mills crush a 3/4-in. product to approximately 19 per cent on 14 mesh, with only one pass through the mills. Each rod mill has taken the place of four sets of 42-in. Garfield rolls with their attendant screens, and is making a product for the fine-grinding department comparable to that formerly made by rolls in closed circuit with screens. The rod mills are lined with wave-type liners of white iron, varying in thickness from 2 to 3 in. The shell and end liners last approximately 600 to 700 clays. Manganese-steel lifter bars, 3 5/8 in. thick, are used, spaced about 11 in. apart, and they give a life of 350 to 450 clays. Fig. 1 shows the general design and thickness of the wave-type liners and lifter bars; 1 1/2 -in. liner bolts are used to fasten the lifter bars to the shell. The shell liners are held in place by the tapered lifter bars. A ¾-in. wood hacking is used between the shell and the liners. The rod-mill scoop has removable manganese-steel lips, which last 250 to 300 days. The scoop proper has shown some wear in spots; and these spots have been protected by rubber bolted over them. Water and milk of lime are added to the elevator feeding the mill, but not enough water to cause a pounding of the rods against the shell. Roughly, the water added amounts to 2.5 to 33 per cent of the ore. Addi-tional water is added to the mill discharge to facilitate distribution to the classifier bowls in the fine-grinding department.

Jan 1, 1938

By Alfred Brooks

Introduction PETROLEUM seepages are known in Alaska at four localities, all on Pacific seaboard. These, named from east to west, are Yakataga, Katalla on Controller Bay, Iniskin Bay on Cook Inlet, and Cold Bay on the Alaska Peninsula. Besides these, a petroleum residue has been found near Smith Bay on the north Arctic coast of the Territory. At Katalla, Cold Bay, and Iniskin Bay there has been some drilling for oil, and in the first field several productive wells have been opened up. Alaskan petroleum so far as its composition is known, is a refining oil, with paraffin base and low sulphur content. Most of what is known of the geology of Alaska oil fields is based on the investigations of Dr. George C. Martin, of the United States Geological Survey. A. G. Maddren, of the same service, has recently made a reconnaissance of the Yakataga oil field. The data to be here presented are chiefly taken from the following publications: G. C. Martin: The Petroleum Fields of the. Pacific Coast of Alaska, with an account of the Bering River coal deposits, Bulletin No. 250, U. S. Geological Survey, pp. 9 to 27 (1905). G. C. Martin: Geology and Mineral Resources of the Controller Bay Region, Alaska, Bulletin No. 335, U. S. Geological Survey, pp. 112 to 130 (1908). G. C. Martin and F. J. Katz: A Geologic Reconnaissance of the Iliamna Region, Alaska, Bulletin No. 485, U. S. Geological. Survey, pp. 126 to 130 (1912). A. G. Maddren: Mineral Deposits of the Yakataga District, Bulletin No. 592,. U. S. Geological Survey, pp. 143 to 147 (1914).

Jan 2, 1915

By Meng-Cherng Sun, Fun-Den Wang, David M. Ropchan

A proposed technique for improving coal-mine roof stability by softening parts of coal pillars along the sides of entries developed from structural analysis is presented. This technique is based on the transference of the high stress concentration in the roof near the upper corners of a rectangular opening to the roof rock and coal over the solid away from the opening. This transferral is accomplished by softening parts of the coal pillars by drilling a series of parallel holes into the coal in the ribs and face of the entry prior to advance. The effectiveness of the pillar softening in terms of reducing the opening width (so that the stress in the roof near the corner is equivalent to that of a narrower opening) ranges from 3 to 5 ft for a 16-ft entry using a series of 4 to 5-ft-deep parallel drill holes of 3 to 6-in.-diam on a 1 to 2-ft spacing for a particular geology. Pillar softening should be highly effective in controlling roof where cutter-roof cave conditions exist, because this technique reduces the high stress concentration in the roof at the upper corners of the opening. It may also be effective for reducing tensile roof failure and coal rib sloughing for certain specific geological conditions. This technique appears to be a simple, effective, and practical method that can be used to supplement conventional roof support methods of roof bolting, timbering, roof truss, and other existing methods in underground coal mines. The authors consider the technique feasible and believe that it merits underground trials.

Jan 1, 1975

By Y. C. Liu

IN the study of the rolling recrystallization of face-centered-cubic metals, a most unusual observation is the frequent occurrence of a sharp re-crystallization texture of cube orientation. Although the general conditions under which this texture occurs are known,2,3 its origin is still not well understood. Based on the observed relationship between the {110}<112> deformation texture and the (113}<211> recrystallization texture, regardless of the effect of alloying elements2,4,5 or the symmetry of the deformation texture,&apos; there is a strong indication that a specific component of the deformation texture is related to a specific component of the recrystallization texture. Using the rotational reorien-tation relationship as a means of correlating the deformation and recrystallization textures, it was proposed that the deformation component which related the cube texture has {358)<523> indices."&apos; The investigation reported here was undertaken to seek experimental evidence for the validity of this proposition. Experimental Procedure Two copper single crystals having an initial orientation within 2" of (358) [523] indices were prepared in the manner described in Ref. 5. The purity of the copper was between 99.94 and 99.97 pct. The original dimensions of the crystals were as follows: specimen A, 0.465 in. thickness, 0.844 in. width, and 0.955 in. length; specimen B, 0.535 in. thickness, 1.120 in. width, and 1.36 in. length: Rolling was done on a laboratory rolling mill according to the following schedule: 0.010 in. per pass to 50 pct reduction in thickness, 0.005 in. per pass to 70 pct reduction inthickness, 0.002 in. per pass to 85 pct reduction in

Jan 1, 1958

By A. M. Gaudin

Of the various reagents employed in the flotation of zinc-bearing ores none have attained the wide popularity that is enjoyed at present by xanthates, copper sulfate and cyanides. This situation suggests the existence of an unusual dependence in the reactions of these chemicals and of sphalerite. A study of the flotative characteristics of sphalerite when using xanthates as collectors, as related to the chemical properties of copper salts and cyanides, has therefore been conducted at the University of Utah by the writer and his associates1 during the period of 1926 to 1929. In perusing the technical literature concerning the flotation of zinc ores and of zinc-bearing lead and copper ores, a striking and general lack of agreement as to the floatability of sphalerite was observed. The underlying cause for the erratic behavior of sphalerite has not been definitely ascertained but the presence in various proportions of iron sulfide in solid solution in the sphalerite has frequently been implicitly regarded as a major factor in this respect. Although the effect of iron sulfide in solid solution in sphalerite has not been investigated in relation to the behavior of sphalerite in flotation, it is likely that it is not as important a factor as was thought at one time. The variable float-ability of sphalerite has led to the use of fairly large amounts of cyanide to prevent its flotation in the case of certain ores, whereas mere fractions of that amount of cyanide, or even none at all, have been sufficient to achieve the same result for other ores2 Similarly, the amount of copper sulfate used to promote the flotation of sphalerite has been found to vary widely. Effect of Copper Salts in Distilled Water on Sphalerite In the work at the University of Utah, over a year was spent in futile attempts at duplicating experiments until it was discovered that the

Jan 1, 1930

By A. E. H. Bergmann

INTRODUCTION The Sachtleben Chemie GmbH in Duisburg, a subsidiary of the Metallgesellschaft AG, operates a new sulfuric acid plant that employs fluid bed roasting of pyrite concentrates. The plant produces about 300,000 tons per year of pyrite cinders from the fluid bed roasting unit. The cinder product consists of 58 percent iron and is about 80 percent by weight smaller than 50 microns. This cinder product was found to be a competitive source material for the cement industry as the iron-containing additive. However, the extreme fineness of the cinder and its dusting tendency were undesirable and an agglomerating technique became necessary. In order to keep the price of agglomerated pyrite-cinders at a competitive level, the agglomerating method must be chosen such a way the capital and operating costs are low. Initial experiments were carried out on a laboratory scale to make an appropriate choice of the agglomerating method. Major goals of agglomerating the cinders were to improve the transportation, storage, and proportioning and metering properties. Minimum specifications are put on the size, size distribution and shape of the product. Criterion for handling is that a minimum of minus one mm. fines are produced after several handlings, while for storage, it is also desirable for the agglomerated product to survive several months in open air. Thermal agglomeration processes such as sintering one known to produce excellent products, but are by far too expensive for our application. For the same reason, granulation, balling, and pelletizing tests with addition of organic binding agents, such as tylose, starch, sulfite wash, molasses, etc. were not continued. The costs for the binding agent was considerable, which is probably due to the high pore volume of our cinders (35 %). Furthermore, the pellets or granules

Jan 1, 1977

By Will H. Coghill

In this investigation, the low-grade red iron ores of Alabama were examined by the use of "heavy solutions."&apos; Ores are generally ground preparatory to concentration and as long as the concentrators make suitable products the effectiveness of the grinding is likely to be unquestioned; but when suitable products are difficult to make, an investigation becomes imperative. In such a case a dissection of the ore might be made to find the cause of the trouble. Such a condition of unsuitable products exists in the low-grade red iron ores of Alabama. They are difficult to concentrate. To be sure it might be said that the concentration of iron ores is a new thing and that the ore-dressing methods are undeveloped, but a glance at the industry reveals an abundance of methods and devices for almost all imlaginable conditions. Concentrating machinery has not been tested in this investigation. When the properties of the ores have been gleaned, the machinery may be used more effectively. Alabama Low-grade Red Iron Ores The Bureau of Mines has undertaken by laboratory methods to select the best means of concentrating the low-grade iron ores of Alabama. These ores constitute the parts of the ore bed left by selective mining. If more of the ore bed could be included in the current output, the mining cost would be reduced and longer life of the district would be insured. This advantage would be reflected by added permanence of churches, homes, schools and every undertaking in the commonwealth. The red ores chosen for this study of effectiveness of grinding are too low in lime to meet the requirements of the blast furnace. If lime is

Jan 1, 1927

By Hillary W. St. Clair

An equation is derived for the rote of reaction of a sphere of metal oxide in a restricted enclosure through which a reducing gas is flowing. The equation takes into consideration the reaction rate coefficient, transport through the gas and through the porous shell of reduced oxide, the rate of gas flow, THIS paper describes a mathematical study of the chemical and physical processes that determine the rate of reduction of solid metal oxide with a reducing gas. The study was a part of a theoretical study leading to the development of a mathematical model for the simulation of the thermochemical behavior of the iron blast furnace. An essential feature of such and the volume of- space surrounding the sphere available for gas flow. The equation is applied to experimental data on vote of reduction of iron oxide in hydrogen. The equation serves as a model for predicting the course of reduction of a particle of. metal oxide in a shaft furnace. a model is an adequate mathematical relationship defining the rate of reaction in terms of all the important chemical and physical phenomena that affect the rate of reaction. This includes not only the reaction rate coefficients, equilibrium ratios, gas composition, and temperature, but also the relevant physical properties of the oxide, rate of gas flow, and relative volumes occupied by gas and solid. In many previous experimental studies of the rate of reduction of oxides by hydrogen or carbon monoxide, the rate of reduction was assumed to be controlled primarily by the chemical reaction at the

Jan 1, 1965

By E. van Walsum

Tunneling methods through rock have, since the successful development of explosives, relied almost solely on blasting. Over the last ten years, rock-tunneling machines (moles) have been developed and some major projects have been carried out successfully with the use of such machines, which rely on the destruction of rock by mechanical means rather than blasting. Various other basically new methods are presently under study, such as the use of laser beams, water jets, etc. For practical purposes, there are presently only two methods commercially available: 1) blasting or 2) tunneling by mole. A contractor would choose at present either one method or the other. Both methods have their advantages and disadvantages (Fig. 1). The thought has occurred that the next practical development in rock- tunneling technology might be a combination of the best features of the mole technique and those of the blasting technique. A preliminary evaluation of this approach indicated that there is definitely a good potential for fruitful developments along these lines. My purpose is to place on record some of the thinking and some of the ideas which were developed along these lines and to point out certain areas where development efforts are required. In trying to find an improved tunneling technique, we looked in particular for the following qualities: 1) safety, 2) continuity, 3) uniformity, 4) automation, and 5) flexibility. TUNNELING BY BLASTING Conventional tunneling by means of blasting proceeds generally in recurring sequences of events: 1) drilling, 2) loading, 3) firing, 4) mucking-out, and supplementary operations (such as scaling and lining). These four operations (drilling, loading, firing, mucking) proceed one after another.

Jan 1, 1970

By J. P. Dunlop

The fact is not.ablc though probably little known that thc Unitcd Statcls is the only nation obtaining and distributing through its Govcrn-ment burcaus any data pertaining to waste metals and drosses. Some foreign goverrlnlents do issuc reports relating to rnine or smelter production of prirrlar~ metals, but none gives in scope and detail t&apos;he information published now by the U. S. Bureau of Mines and formerly by the U. S. Geological Survey; and this is despite the fact that the funds annually allotted for those purposes are insignificant in comparison with allotments for the preparation of data relating to other industries of like importance. The earliest data on the production of metals from secondary sources in the United States were contained in a press bulletin issued by the U. S. Geological Survey on Jan. 4, 1909. The information published was that for thc year 1907 obtained ant1 compiled by C. E. Siebenthal, who was one of the first to visualize the growing importance of the scrap-letal indust,ry. Thc Nationd Conscrvation Commission had emphasized its opinion that the known domestic supply of certain kinds of the morc important irietals was being rapidly marketed and that while there was no immediate cause for concern it was best to conserve such resources. Not only had there been a lanlentable lack of any data regarding the quantity of scrap inetals available or used but also gross carelessness and indifference in the segregation, collection, and effective use of scrap material. Siebenthal realized that even approximately correct statistics of recoveries from the more important base-metal scrap and drosses wcrc nearly as essential t,o both producers and consumers as the stat&apos;istics of the output of primary metals. There were not then nor are there now sufficient funds for complete collection of data, nor was it considered the province of the Geological Survey t&apos;o do more than determine approximately the recovery of secondary metals for use in supplementing those given for the primary metals. Undoubtedly the first bulletins issued did not give the full output, for it takes time to establish contacts for an inquiry covering so

G. A. ROUSH,* South Bethlehem, Pa. (written discussion?).-Mr. Frey is correct in his impression that ice floats, but "frazil" ice happens to be the exception to the rule. The requirements for the formation of

Jan 12, 1919

By Chairman Hill H. H.

The Round Table Discussion on Petroleum Engineering Research was planned for two purposes. First, to review the work that has been done by petroleum engineers during the past few years on problems that have confronted the industry and, second, to suggest new studies that should be made either on the problems that have been the subject of research during the past or on problems that have arisen only recently. It was believed that by holding an informal discussion of the problems in which the petroleum engineer is vitally interested it would be possible to bring out new ideas as to the relative importance of the different problems that should be studied and to suggest new methods for attacking some of the problems that have resisted the energies of research workers throughout the industry. It was also believed that by arranging for an exchange of experiences between the different engineers it would be possible to prevent a large amount of duplication of effort in conducting research work. Those engaged in petroleum engineering research realize that there is a broad field for study and by coordinating the work it will be possible to obtain the maximum amount of information in the shortest possible time. In planning the program on Petroleum Engineering Research, nine subjects were selected for discussion and each was assigned to a man who is doing work on that subject. These men were asked to lead the discussion on the problem assigned to each one. An effort was made to choose problems of a practical nature and upon which considerable work is being conducted at the present time. Some of the men who were asked to lead the discussion were unable to attend the meeting but most of them submitted a written discussion- of the subject assigned, with the result that there was a discussion of eight of the nine problems. Professor Uren, who was asked to lead the discussion on the subject of Recent Developments in Methods for Reducing Gas-oil Ratios, was unable to attend the meeting and advised that he did not have any new ideas to contribute.

Jan 1, 1928

By J. W. Turrentine

SECONDARY fertilizer minerals include borax, gypsum and sulphur and such compounds as the sulphates of copper, magnesium, manganese and zinc; also the carbonate and oxide of magnesium. Potash, phosphates and nitrogen are generally considered to be primary fertilizer materials. The growing plant, under the average conditions of growth, is able to get from the soil the mineral elements required for the completion of its life cycle. The elements taken up are numerous and the vital functions of some of them yet remain to be determined. However, in the commercial growing of the plant (farming) something much more than the mere completion of a life cycle is required. There the maxi- mum possible growth of plant or yield of seed or fruit are the objective and for that objective the average soil is deficient in some elements, and additions from artificial sources are desirable. Commercial fertilizers (15,000,000 tons in 1946) are designed to supply those deficiencies. Long experience has taught that nitrogen, phosphorus, and potassium are the elements most apt to be required and in a greater degree, and to supply them is the-basic function of the fertilizer industry. Thus nitrogen, phosphate, and potash are designated as the major plant-food materials. But other mineral crop nutrients may likewise be deficient in varying degrees as determined by diagnostic techniques, soil tests, plant analysis and foliar symptoms,3 calling for their addition from artificial sources if maximum crop yields are to be obtained. Because used in lesser amounts and frequently in relatively minute amounts as compared with the major three, they are designated either as "minor elements," or, if used in larger amounts, as "secondary elements." Thus, included under the two designations, in alphabetical order, are: borax; copper sulphate; magnesium carbonate, oxide and sulphate; manganese sulphate, and zinc sulphate. Obviously, the sulphates of the metals copper, manganese, and zinc cannot be considered as "industrial rocks," but they are given brief mention for whatever interest may pertain there to.

Jan 1, 1949

By H. W. Paxton, G. M. Pound

A method is outlined for taking into account variation in chemical potential of both components in evaluating capillary effects at growing interfaces. The results are compared with experiment, and seem to be in reasonably good accord for Widman-statten ferrite growing in austenite. ENERY pointed out that during the steady-state growth of phases with a rather small radius of curvature at their advancing edge capillarity cannot be neglected. By proper application of the Laplace equation a correction must be made to the activity gradients down which diffusion occurs. Subsequent workers have concerned themselves with attempts to evaluate specific cases by the use and modification of the principles laid down by Zener.2-5 To solve the problem in its simplest form it is necessary to assume thermodynamic equilibrium at the interface and to select some criterion which will allocate the available free energy between reversible and irreversible processes. Zener chose to assume that the division should be made such that the new phase grew at the maximum rate. Other workers have used the same2,3 or different assumptions, e.g., maximum rate of free-energy dissipation,4 minimum rate of entropy production.5 Li6 has proposed that the "thermokinetic potential" should be a minimum at steady state. The purpose of this presentation is to note that most prior treatments have considered variations due to capillarity only in the chemical potential of the mobile constituent, and that a more consistent treatment must involve a consideration of the variation of chemical potentials of both solute -and sol- vent in a binary system.* As an example, the way in which this arises for ferrite growing from austenite may be illustrated by reference to Fig. l(a). The line OABC shows a typical variation of carbon activity with composition at one atmosphere pressure (at a transformation temperature below A3). In the tip of a growing ferrite plate with a hemi-cylindricab leading edge of radius ?, the pressure due to capillarity is*

Jan 1, 1963

By E. A. Beck

For a number of years many attempts have been made to use thermit in order to do away with piping in ingots. Some of these attempts were successful, while others did not give the expected results. Nearly every plant had its own method of using the thermit, and no special care was taken to study the results or to find the causes for lack of success. Formerly the principle of the process was to decrease the piping by introducing a can filled with thermit, attached to an iron rod, into the head of the ingot directly after it had been poured. In this case the thermit reaction took place in the upper part of the ingot, and it was thought that through the heat produced the head would keep liquid longer and piping thus be reduced. In other words, the aim was to keep the head of the ingot open by making use of the heat of the thermit reaction, which would thereby give the gases in the steel sufficient time to escape. This result can be attained by the application of a large enough quantity of thermit, but it would not be economical in general practice, and could only he used for high-grade material. Many steel-makers abroad and in this country have had this experience. The Th. Goldschmidt A. G., Germany, has, therefore, made a special study of this question with the cooperation of a well-known steel company, and has worked out a new method for the application of thermit for this purpose. The results obtained have been most satisfactory and reliable, and this process is now used in Germany on a large scale in many prominent steel-works. The thermit is applied in cans, as in former years, but the principle of the process is entirely different. The object of using the thermit is not to heat the steel and keep it liquid,

Jan 1, 1914

By W. Luyken

A NUMBER of articles have been published, notably those by R. S. Handy, R. T. Hancock and A. P. Watt in Engineering and Mining Journal, dealing with the calculations involved in ore dressing.. These publications demonstrate both, the importance of the subject and the lack of success in developing a generally recognized method for comparing enrichment effects. Considering that we may wish -to compare enrichment results on similar or dissimilar ores, that we may desire to make the comparison on the basis of either the absolute or the economical efficiency, and that the number of factors upon which the result depends is large, the question arises whether it is possible to set up a positive method for such calculations. In the following pages it is our aim to show that a sure, complete and successful way to overcome existing difficulties has been found. GRAPHICAL ANALYSIS OF ORE-DRESSING PROCESSES The following is from Truscott&apos;s Text Book of Ore Dressing (London, 1923) x = assay of ore treated (feed). y = assay value of the concentrate. z = assay value of the tailing. a = weight of feed. b = weight of concentrate. c = weight of tailing. C = fractional concentration = b/a= x-z/y-z (1) K = ratio of concentration = 1/C = a/b =y-z/x-z (2) R = fractional recovery = yb/xa = Cy/x. (3) 100R = percentage recovery. Copt = theoretically best concentration. 100 - Copt = waste in the feed.

Jan 1, 1929

By V. R. Garfias

It has been repeatedly questioned whether estimates of oil reserves are of any practical value, as the greater number of such calculations previously made have subsequently been proved to be grossly inaccurate. But even admitting partial justification for such statements, it must be evident that some idea, however approximate, of the available reserves of essential minerals is of vital importance in mapping their development and the future trend of the related industries, particularly if it is kept constantly in mind that these estimates—which are never intended as a final word—must be continually subject to revision in accordance with the changes in their component factors. The value of these estimates, therefore, hinges on the clear understanding that they can only apply within the limited time when the controlling factors remain unchanged. It should be understood, however, that while estimates of possible and probable oil deposits are as a rule but idle conjectures, appraisals of proven oil reserves can undoubtedly be made with an ever-increasing degree of accuracy. And it is with this in mind that in the present study the endeavor has been to estimate only the world&apos;s proven oil reserves—the oil that yet remains underground in the producing fields—and their logical extensions, and to leave out of consideration the questionable volume of the probable and possible oil reserves. In Table 1 the countries at present producing oil in commercial quantities are listed in the order of the magnitude of their proven reserves. As shown in the table, the world&apos;s proven oil reserves are estimated at over 24 billion barrels, while the total production to the end of 1932 aggregates nearly 23 billions. Past production represents, therefore, 48 per cent, and proven reserves approximately 52 per cent of the total. About 61 per cent of the reserves are located in the American continent and close to 33 per cent in the Near East fields of Russia, Iraq and Persia. It is interesting to note that the proven reserves in the important producing regions almost equal if not exceed their production to date. The Mexican fields are a remarkable exception in this respect since they produced over 135 billion barrels and have proven reserves estimated at only 300 million barrels.

Jan 1, 1933

By Carl Thieme

INDUSTRIAL specialization has rapidly created a demand for new and better alloys. A more thorough understanding of the requirements of specific industries and the discovery of processes by which it has been made possible to utilize certain metallic elements in larger quantities, together with greater purity in most virgin metals, has resulted in a great increase in the number and variety of alloys. This increase in the number of elements entering into non-ferrous alloy manufacture has increased the contamination in secondary metals, as received by the smelter. In order to successfully refine scrap of a much more complex nature it has been necessary for the smelter to install new equipment and to constantly search for new methods of refining as well as to improve the methods already in use. In some instances it is largely responsible for specialization in the secondary metal industry. It is usually necessary to remove the contaminating impurities in scrap or eliminate to a degree not objectionable, no matter how introduced. In order to know what metals or elements are of an objectionable nature, the smelter must make a study of the effect of single elements and combinations of elements on many of the physical and mechanical properties, such as strength, ductility, color, hardness, casting soundness, etc. The smelter of secondary metals must be able to utilize scrap materials of all kinds, for, sooner or later, most fabricated metal parts and the waste products formed during the process of manufacture find their way to the smelter. In addition, the smelter, in contracting for salvaged material from the producer, gets some undesirable and unusual materials. The value of secondary metals and the importance of their recovery has increased in recent years and it is no longer sufficient to recover the base metal only, such as copper from copper-bearing material, but it is essential that other elements present be recovered and converted into useful form.

Jan 1, 1928