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By Zay Jeffries

OF the new production of non-ferrous metals in 1930 gold will rank first in value. We usually think of copper as the most important non-ferrous metal. The copper industry as a whole, that is, adding copper production to copper fabrication, is the largest non-ferrous metal industry. Prior to the world war; however, gold led in value of new metal produced. During the war copper passed gold in value, but gold regained its position during the 1921 depression. For the past several years copper has again passed gold, but in 1930 gold promises again to regain the lead. The gold producer has at times been called a social parasite, largely because we ' cannot eat or drink gold, or because we cannot use it for clothes or for the construction of buildings. Let us briefly examine this accusation.

Jan 1, 1930

By C. E. Siebenthal

produce attractive and consequently more salable products. It would seem, however, that if solder and babbitt were cast in closed molds, just as good practical results would be obtained by the user, without his being able to give preference to solders of unnecessarily higher grade on account of their appearance. It would be hopeless for any one. manufacturer of solder to undertake a change of this kind, but if all manufacturers of solder agreed upon it, they would be able, in my opinion, to get the users of solder to take, and to approve by their practical tests, metals containing less tin than they have been accustomed to. The same is true with regard to babbitt metals. An illustration of how, in the use of an alloy, appearance sometimes is deceptive, is to be found in the case of what may be called intermediate grades of babbitt. I am thoroughly convinced that high-tin or high-lead babbitts are better than those containing both lead and tin with relatively high percentages of each. A high-tin babbitt should not contain more than about 10 per cent. of lead, and a high-lead babbitt should not contain more than 10 per cent. of tin, unless the percentage of antimony can be correspondingly increased. The intermediate babbitts, such as those that contain from 30 to 70 per cent. of lead or tin, may give nice appearing castings that flow easily, but they have not the serviceability of the high-lead or high-tin babbitts. Their hardness diminishes very rapidly as the temperature rises, and they have a relatively low softening point due to the eutectic components present. The Cadmium Supply of the united States* C. E. Siebenthal, † Washington., D. C.—From being one of the most maligned of metals—a veritable bugaboo—cadmium has almost overnight become respectable, though its slender claim to respectability rests almost wholly on the possibility of its substitution for tin. Preliminary to any campaign for such substitution, particularly for enforced substitution, the possible supply of cadmium should be determined as closely as possible; for that reason the statistical inquiry of which this paper embodies the results was undertaken. Production Cadmium is marketed in two forms, as metallic cadmium, in sticks or bars, and as cadmium sulfide, the pigment. The metal has found its greatest field of use in this country as a component of an easily fusible alloy that is used in automatic fire extinguishers. The sulfide is used to some extent in paints but chiefly to give color and luster to glass and porcelain. The metal was first made in this country by the Grasselli Chemical

Jan 1, 1919

By C. MeCulloch

A NOVEL practice in the bituminous coal industry is the accelerated method of burning coal to ash used in the laboratory of the Fidelity washery of the United Electric Coal Companies, Du Quoin, Ill. Development of this method has supplanted the tedious float-and-sink process for plant control at this plant. In normal operation the plant operators have available within thirty minutes the accurate ash percentage of the coal loaded in the railroad cars and can therefore make adjustments to maintain a practically uniform quality of washed coal, regardless of the variations in washery feed.

Jan 1, 1937

By H. M. Shepard

THE copper industry operated at high capacity throughout 1947, with no serious tie-ups in operation as was the case in 1946, when almost the entire industry was shut down by a four-month strike. Refined copper production in the United States averaged 94,250 tons for the first eleven months and deliveries to domestic consumers, including foreign copper for domestic consumption, averaged 114,000 tons per month. On April 29 the import duty of 4d per lb was suspended until March 31, 1949. Copper prices fluctuated considerably for a short time thereafter. Over the year the price of domestic electrolytic copper at refineries on the Atlantic seaboard advanced from 19.225¢ on Jan. 2 to 21.200d on Dec. 24.

Jan 1, 1948

By R. Moldenke

The presence of nickel-chromium in pig iron made fro111 Cuban oles is so well known that the word "Mayari" is unconsciously associated with it. Since 1904, when exploration of the Mayari deposits of iron ore in northeastern Cuba was undertaken, there llas been increasing interest in these ores. Tlie Transactions contain numerous references to t1ieln.l This iron ore, which is shipped to the Tinited States in the nodulizecl state, has been thoroughly tested and found very valuable; the deposit covers over 25,000 acres and there is in sight over 500,000,000 tons of ore that, by systematic mining, runs practically constant in composition. With nickel and chromium present, also titanium in sufficient quantities to attract attention, as well as extremely low phosphorus and sulfur contents, the iron founder is naturally interested in the utilization of RInpari ore for pig iron for the better grades of finishrtl iron products. The present point of coilsn~iil)tion ol ILlapri ore is at Sparrow's Poi111, where hlayari pig iron of ally desiretl coml>osition is made. The composition of the dried ore is about as follows: Iron -29 per cent., silica 3 pc.r cent., nickel 1 per cciit., chroiniun~ 1.5 per cent., alumina 11 per cent., ant1 coinbined water 13 per cent. When nodulized, the iron runs up to nearly 56 per cent., the silic:~, :tlumi~i:i, nickel, and c~llromiurn are slightly highr than the arno~l~its just given. Practically all the, combined wntcr is driven off aild the iiodulizccl ore carries only a few- tenths per cent. of 1 C. M. Weld: Residual Rrolvn Iron Ores of Cuba. Tmns, (1909) 40, 299. C. K. Leitll nnd If'. J. Mcncl: Origin of Iron Ores of Central and Northeostr~n rlbn. Trans (1911) 42, 00. C. W. Hayes: May:~ri and Mos Iron-ore Deposits in Cuba. Idem, 109. J. E. Little: Maynri lron Mincs, as Developed by the Spanish-American Iron ('0. Idem, 152. J. F. Iie~np: M'ryari Iron-ore Dcposi(s. Trans. (1915) 61, 3. C. K. Leith 2nd N. J. Mead: Additional Data on Origin of Lateritic Iron 01cs or Eastern Cubn. Tmns. (1916) 63, 75.

Jan 1, 1923

By R. Moldenke

The presence of nickel-chromium in pig iron made fro111 Cuban oles is so well known that the word "Mayari" is unconsciously associated with it. Since 1904, when exploration of the Mayari deposits of iron ore in northeastern Cuba was undertaken, there llas been increasing interest in these ores. Tlie Transactions contain numerous references to t1ieln.l This iron ore, which is shipped to the Tinited States in the nodulizecl state, has been thoroughly tested and found very valuable; the deposit covers over 25,000 acres and there is in sight over 500,000,000 tons of ore that, by systematic mining, runs practically constant in composition. With nickel and chromium present, also titanium in sufficient quantities to attract attention, as well as extremely low phosphorus and sulfur contents, the iron founder is naturally interested in the utilization of RInpari ore for pig iron for the better grades of finishrtl iron products. The present point of coilsn~iil)tion ol ILlapri ore is at Sparrow's Poi111, where hlayari pig iron of ally desiretl coml>osition is made. The composition of the dried ore is about as follows: Iron -29 per cent., silica 3 pc.r cent., nickel 1 per cciit., chroiniun~ 1.5 per cent., alumina 11 per cent., ant1 coinbined water 13 per cent. When nodulized, the iron runs up to nearly 56 per cent., the silic:~, :tlumi~i:i, nickel, and c~llromiurn are slightly highr than the arno~l~its just given. Practically all the, combined wntcr is driven off aild the iiodulizccl ore carries only a few- tenths per cent. of 1 C. M. Weld: Residual Rrolvn Iron Ores of Cuba. Tmns, (1909) 40, 299. C. K. Leitll nnd If'. J. Mcncl: Origin of Iron Ores of Central and Northeostr~n rlbn. Trans (1911) 42, 00. C. W. Hayes: May:~ri and Mos Iron-ore Deposits in Cuba. Idem, 109. J. E. Little: Maynri lron Mincs, as Developed by the Spanish-American Iron ('0. Idem, 152. J. F. Iie~np: M'ryari Iron-ore Dcposi(s. Trans. (1915) 61, 3. C. K. Leith 2nd N. J. Mead: Additional Data on Origin of Lateritic Iron 01cs or Eastern Cubn. Tmns. (1916) 63, 75.

Jan 1, 1923

By Robert Y. Grant

This study outlines the history of metal mining in Japan and the characteristics of the industry as they existed from 1925 to 1945. Mining and milling operations are described together with the role of the Japanese Government. A description of post-hostilities conditions and the present state of the industry is included. MANY of Japan's larger and better known mines date back to the early centuries of the Christian Era. The first stimulus to mining in Japan came through the growth of Buddhism, A. D. 600 to 700, and the attendant need for copper and other metals for temple ornaments and statues. During the Feudal period, 1333 to 1568, mine operations were expanded to meet the demand for ornament metal and for financing of campaigns. After removal of the seat of government from Kyoto to Tokyo, about 1600, the Tokugawa Shogunate placed great emphasis on mining, and many new mines were opened, some of which are still operating. Toward the end of the Tokugawa period, mining had declined sharply from its earlier peak. The easily worked, high grade portions of the orebodies had been exhausted, and the mining techniques then available could not exploit the deeper, lower grade ores. Similarly, extraction of metal from the sulphide ores presented a major problem. With the Meiji Restoration in 1868 and the rapid opening of the country to western ideas came a rejuvenation of the mining industry. Mining, milling, and smelting processes were greatly improved, resulting in the extension of development work into hitherto inaccessible portions of orebodies. The demand for metal during World War I stimulated activity throughout the industry; copper mining, particularly, expanded to a point where Japan ranked second among world producers.* During the depression following the war, mining underwent a severe contraction in activity, recovering slowly during the late 1920's only to undergo a further setback in the worldwide depression which started in 1929. Mineral output declined in 1930, but the beginning of Japanese expansion, 1931 to 1932, brought about an increase in the output of mine products starting between 1932 to 1934. Production continued to rise, the peak output being attained 1939 to 1943 in virtually all commodities. The greatest production of iron ore, chromite, and manganese was not experienced until 1944 when blocked imports, coupled with strong demands for steel, provided the needed incentive. Through necessity, Japan produced much of her mineral needs from her own mines at high cost during World War 11. Taking the 1932 to 1936 period as an average, however, Japanese mines produced only 16 pct of the iron available to industry, 8 pct of the lead, 33 pct of the zinc, and 68 pct of the copper. Nearly all of Japan's output of gold, silver, copper, lead, and zinc between 1925 and 1945 came from 30 to 49 pct of the mines for which production data are available; for example, 66 of 174 gold-silver mines accounted for 98 pct of the output of this group. Further analysis of mine output indicates that a large part of Japan's metal output was derived from a few large mines; about 10 gold-silver, 15 copper, 3 lead-zinc, 5 manganese, and 2 iron mines account for most of the production. Many of these mines have been operated for 200 to 400 years. With the

Jan 1, 1952

OPEN-HEARTH refractories are not merely an accessory to the furnace. They are the furnace, to all intents and purposes. The steel work of the main structure is merely an open frame which helps to support the refractories; and the regenerators, a necessary part of the furnace system, consist almost entirely of refractories. Not only do refractories constitute the essential part of the furnace, but they also carry the liquid steel all the way 'to the point where it begins to solidify. On leaving the furnace the liquid passes through a refractory runner into a refractory-lined ladle, then through a refractory nozzle closed by a refractory stopper on the end of a rod protected by refractory sleeve bricks. The liquid is sometimes sent through an additional refractory- lined tundish, a supplementary ladle, or a refractory runner for bottom pouring, until it finally enters the iron mold in which it solidifies. Even in the mold, refractory materials are sometimes used to provide a nonconducting "hot top." This series, from runner and ladle to hot top, inclusive, is often referred to collectively as the "pouring-pit refractories." REFRACTORY RAW MATERIALS The raw materials available are best classified into basic and acid types. The principal basic raw materials are magnesite, dolomite, and chrome ore. The principal acid materials are silica in various natural forms, and fireclay. Magnesite. Austria was the principal source of magnesite (MgC03) until recent years, when the Province of Quebec, in Canada, and the states of Nevada and Washington became important sources for the American steel industry. More recently these natural sources have been supplemented by the so-called "sea-water magnesite"-which is the name somewhat incorrectly given to magnesium hydroxide obtained as one of the products

Jan 1, 1951

By M. G. Benz, J. F. Elliott

Otto Schaaber (Institut für Harterei-Technik, Bremen -Schönebeck, Germany)— Langenberg, Pestel, and Honeycutt gave an interesting example of the grain refining effect nonstationary magnetic fields may execute on a solidifying metal. Probably some additional comments, based on more than a decade of experience with this method of influencing crystallization, may be useful. They refer to an attempt to explain the mechanism of grain refinement by such fields, and to recent European developments which have not been mentioned in the paper. I. During studies of the temperature distribution in a metal body near the phase boundary solid/liquid, an anomaly was observed under certain special conditions: a) direction of heat transfer as horizontal as possible, b) steady state (equilibrium, i.e,, solidification resp. melting rate exactly zero). In the liquid phase, immediately adjacent to the phase boundary, the temperature was found to be constant over an appreciable distance in spite of a high value of heat transfer (40.000 to 70.000 keal/ m2h).3 Convection, which might explain this phenomenon, could not be observed. Therefore another explanation had to be sought. The assumption that a metallic melt, especially at temperatures near the point of solidification, contains some sort of atomic arrangement with a higher degree of order than the surrounding liquid, now is generally accepted. Considering the differences in energy between such an arrangement and its environs, a transport of heat even in absence of any temperature gradient is conceivable by continued formation and redissolution of regions with a higher degree of order, i.e., with lower energy level.3 At this stage, it was not necessary to postulate any special condition as to the form or size of these regions or the distance between arrangements to be newly formed and those to be redissolved. However, a simple consideration shows that an energy transfer from one region to another will only be possible without loss of energy, if the distance between will be equal to the lattice parameters, and if, secondly, crystallographic axis or planes will be parallel.4 By the way, this assumption might give a reasonable explanation of the well known orientation effect of the heat flow during solidification. Any measures to prevent columnar crystallization should act upon this ordering mechanism: a) the regions with a lower energy (higher order) should not be allowed to arrange themselves parallel to the direction of heat flow, and their growth should be disturbed; b) all conditions leading to an appreciable heat flow of uniform direction should be avoided or removed. Condition a) may be satisfied by a physical force preferably under 90 deg to the main axis of the columnar crystals (i.e., parallel to the solidification front) acting on the ordered regions; condition b) by equalizing any differences in

Jan 1, 1962

By Gerhard Derge

A SERIES of studies of the corrosion of tin is under way in the Metals Research Laboratory at the Carnegie Institute of Technology. The complete program includes examination of the corrosion properties of high-purity tin and the changes produced in these properties by the addition of varying amounts of alloying elements. Other studies of this subject have been made recently under the sponsorship of the International Tin Research and Development Council, but these researches have been confined largely to the weakly acid environments commonly encountered in the canning industry.1 There is little information available regarding the corrosion of tin under alkaline conditions, but such data would be of value, for a large amount of the metal is used under such conditions. The potential measurements to be described were made because they seemed to offer the most rapid method for obtaining a general view of the conditions to be encountered in such service. These experiments will also serve to establish a technique that will be of value in further studies. It must be emphasized that the results reported are those of controlled laboratory experiments and that the conclusions drawn cannot yet be applied to service conditions; rather, they point to the directions in which more exhaustive experimental work may be done to best advantage. EXPERIMENTAL PROCEDURE The first work was devoted entirely to the problem of obtaining reproducible results from a series of potential measurements. Only the methods finally adopted as standard will be described here, except when the variations from these have furnished results of interest. The cell used is shown schematically in Fig. 1. The electrolyte is contained in the vessel A (an inverted bell jar), whose ground top is fitted to the transite-board lid B. The controlled atmosphere can be admitted

Jan 1, 1938

By W. F. Mattes

The manufacture of steel rails in the United States upon a large scale may be roughly dated from the years 1875-76, and the same years witnessed an active movement among the railroads toward the adoption of heavier and improved patterns. In this movement each road was a law unto itself, and the "personal equations " of some scores of engineers were so freely injected into the calculations that patterns were multiplied in the most absurd and mischievous manner, until at length the burden upon the mills became wellnigh unendurable, and called forth a vigorous protest in Mr. Holley's paper,* read before the Institute in February, 1881. There were then regularly manufactured in the various mills of the United States, no less than 119 different patterns of steel rails, subject to current order, of which 64 per cent. were embraced under five weights per yard. Commenting upon these and other figures there given, Mr. Holley stated as the primary object of his paper, " to show that,, while this multiplication of rail-patterns is an annoyance and an expense to rail-makers, it is a source of immense loss to railway companies." Since 1876 the increase in gross annual tonnage upon our leading lines has been very great, and has been accompanied by an increase of wheel-loads and running-speeds. As the average weight of the rails of 1876 was by no means excessive, the growing deman Is of traffic have slowly driven the roads toward stiffer sections, inaugurating a movement that now promises to become epidemic. In 1876 a 67-pound rail was a first-class equipment; to-day everything under 75 pounds is light, and many 80's are coming into use. European practice has long been heavier than ours; in part because the higher cost of sleepers has led to an average of 3-feet spacing, instead of two-feet as with us. The old 84-pound double-header, and Sandberg's 80- and 89-pound rails, respectively 51/4 inches and 591/2 inches high, are reported common on English roads; and he is strongly advocating the general adoption of the 100-pounder shown in Fig. 7, with what success I have not learned, except that the Belgian government has ordered a lot. Mr. Sandberg points out the undesirability of frequent changes of pattern, and the recent rapid growth in traffic-requirements; prognosticates a continuance of this

Jan 1, 1887

By Edward Wisser

The environment of an ore body is taken to mean not only its physical surroundings but every factor, passive or active, that conditioned the ore shoot, saving only the original composition of the solutions that formed the shoot. Collection of data related to the shape and characteristics of veins should be followed by correlation of the data and the formulation of generalizations regarding ore formation. The nature of the criteria used in arriving at these generalizations is discussed. Certain of the criteria, when used with an understanding of their underlying causes, become "ore- guides." In the course of his study the geologist must not confine himself to the immediate surroundings of the veins, but should attempt to work out the geologic history of events culminating in the crucial epoch for any mining district, the period of mineralization. The work may involve study of features far removed from the veins and related to them only indirectly. It commonly means thorough study of the geology of the entire region surrounding the ore deposits. THE following question has been suggested for discussion: [t] "Are there any criteria by which one can determine when mining operations have reached the roots of an ore deposit?" The question deals less with the roots of a particular ore body than with the lower limit of the vertical range within which ore bodies may be expected. It concerns a critical line upon the longitudinal vertical projection of a vein.[t] Below this line it is useless to look for ore shoots; above the line exploration below the bottoms of individual ore shoots may be justified. Can we learn to determine the position of such a line? In some multivein districts the line for any given vein may be approximated by simple interpolation or extrapolation. Where this is possible the bottoms of the lowest ore shoots in the various veins are points on an imaginary, gently rolling surface. The trace of this surface upon the vein is our critical line for that vein. The imaginary surface rolls so gently that it may be projected from two or more known veins to an unexplored vein near by. Here is a criterion for the bottoming of ore that has nothing to do with changes in the appearance of the vein in question; it rests solely on the depth at which the ore bottomed in adjacent veins. The method is not applicable in districts only slightly explored in depth, nor where the lower limit of the ore-bearing horizons

Jan 1, 1939

By J. A. Stachura

Continuous mining machinery provides the coal industry with one way to compete for a larger share of the total energy market. Various types of machines are discussed and some of the problems with continuous miners, encountered by operators, are reviewed. Equipment manufacturers are working with mine personnel to provide solutions for problems that arise. While coal production over the past 25 or 30 years has been on a horizontal plane, coal's share of the total energy market has declined. To participate more effectively in this total energy market, it is necessary to produce coal more efficiently. It is the obligation of all management, employes, and mining departments to gear the deep mining industry to the rapid progress and changing of today's modern industry. This can be accomplished in the near future with the selection of the proper type of continuous miner best suited to each operator's individual situation. In most mining operations there is tremendous incentive to undertake the continuous mining program. It can reduce the size of the mine greatly by permitting a minimum of working places; it makes pillar recovery work more efficient from the standpoint of overall cost, amount of coal recovered, and safety. The work force can be reduced materially permitting closer and more efficient supervision. It simplifies maintenance because equipment can be more readily standardized. The trend of the coal market favors the use of continuous mining machines. Although there appears to be a general feeling that continuous mining is still a relatively new program and will be slow in replacing conventional mechanical equipment, the fact is that tremendous strides have been made since the first machines were installed in 1948. This program is advancing at approximately the same rate that mobile loading machines replaced hand loading. From 1948 to 1955 there were approximately 450 continuous mining machines in service. In October 1959, a survey revealed that there were more than 700 continuous mining machines in service. Many operators have expressed a desire to undertake this program, but they feel that they could not do so at this time because of one or more of the following reasons: 1) the thickness of their coal seams, 2) seam characteristics, 3) soft bottoms, 4) bad roof conditions, 5) size consist, 6) insufficient flexibility in machines, 7) difficult ventilation problems, and 8) high maintenance costs. With the realization on coal about the same today as it was in 1948, or slightly less and since coal is still failing to participate to a greater degree in the total energy market, it is not surprising that the coal industry is desperately exploring more economical methods for deep mining. The manufacturers are aware that the coal industry is willing to invest in continuous miners if the equipment is built for maximum flexibility, will produce higher tons per man, and assure long life between overhaul programs. CONTINUOUS MINING MACHINES Before discussing details regarding the selection of a continuous miner, let us have a preview of some of the continuous mining machines which are available to the coal industry today. Jeffrey Manufacturing Co.: The machine shown is the Jeffrey 76 A.M. Colmol. This is their most widely used miner, and has been particularly successful in central Pennsylvania and in high-wall mining in western Kentucky. One of the outstanding features of this auger-type miner is its portability. The entire mining range can be changed from its lowest point to the maximum height without stopping the mining operation. Jeffrey 76 B.M. Colmol: This machine is similar to the 76 A.M. model; however, it is built bigger and stronger for a mining range of 50 1/2 to 72 in. This is the model that is now available (Fig. 2). Jeffrey has added two arms to the top row, omitted the odd arm in the bottom row, thus permitting a 50 pct larger throat opening. This eliminates one

Jan 1, 1961

By A. Styka, G. Fischer, S. Tour

Described herein are the results obtained during research work involving coating titanium alloys with molybdenum by vapor-deposition methods. Results show that the method can be used successfully to deposit hard adherent wear-resistant coating of methodmetallic molybdenum on titanium or titanium alloys without changing the microstructure of the titanium base. PRODUCTION and use of titanium and its alloys have increased tremendously in the past few years. The physical, mechanical, and chemical properties of this engineering metal have caused considerable enthusiasm among metallurgists and engineers. However, as with all materials, there are some drawbacks. For example, titanium is susceptible to seizing and galling on wearing surfaces. In order to produce a good wear-resistant surface, many investigations have been conducted evaluating oxidizing, carburizing, nitriding, carbonitriding, sili-conizing, and chromizing of titanium. All of these processes require high temperatures for rather extensive periods of time. It has been possible to produce hard surfaces on titanium and its alloys by a number of these processes at the expense of a deterioration of the physical properties of the base material. A practical solution to the problem of providing titanium and titanium alloy parts with a satisfactory wear-resistant nongalling surface must be one that does not involve excessive temperatures for long periods of time. Sam Tour & Co. Inc. has completed a research and development contract for the United States Army Ordnance Corps on vapor deposition of molybdenum on titanium and titanium alloys. On the basis of results obtained from the research program, titanium alloys can be coated successfully with molybdenum to provide a hard wear-resistant surface without harm to their base mechanical properties. The remainder of this article is a description of the techniques used to apply the coating and the results obtained from wear tests on molybdenum-coated titanium. Theory Basically, the technique used was the application of molybdenum by a vapor-deposition method, thermal decomposition of molybdenum hexacarbonyl [Mo(CO)] with hydrogen as the carrier gas. The selection of this method was based chiefly on the following considerations: 1—low plating temperature which would minimize excessive grain growth, 2— low decomposition temperature of the carbonyl, 3— possibilities of controlling the hardness of the plate by adjusting the carbon content using the plating temperature and pressure as the primary variables, 4—use of high vacuum, thereby avoiding unnecessary oxidation and other complex reactions with the atmosphere. Free energy data1 show the strong tendency for titanium to combine with O2 N2 or carbon from normal temperatures to temperatures above its melting point. To maintain the titanium in a film free condition, the use of as high a vacuum as possible is indicated. The literature' indicates that the reaction product of hydrogen with titanium is unstable in vacuum at around 400°C. 5—Although it is indicated from the thermodynamic standpoint that there is little possibility of removing carbon from either titanium or molybdenum, the work of Lander and Germer -ndicates that the use of a suitable H,/CO ratio is somewhat effective in minimizing carbon deposition. 6—Availability of molybdenum carbonyl. In the simplest form, the conditions of equilibrium3 in chemical reactions involving decomposition of carbonyl are as follows: Mo (CO) ? Mo + 6CO 2CO * C + CO,. The plating rate is proportional to the rate of evolution of CO from the decomposed carbonyl, i.e., it is proportional to the pressure of the gaseous decomposition products. Carbon released from CO gas is the significant constituent for the variability of the physical properties of the product. High carbon deposition is favored by increasing pressure. Limitations are imposed in the selection of plating temperature and pressure. Excessive temperature re-

Jan 1, 1956

By ARTHUR THACHER

PRIMITIVE man supplied his wants as they arose; as he became more civilized he anticipated them by producing more regularly and storing the products for future use. This tended to cheapen' production and prevent ' violent fluctuations and therefore tended to increase consumption. In order to anticipate our wants, we must know what these wants will be, and this can be .determined only by statistics. 'While we have made great progress in gathering statistics, they are still far from what they should be; especially metal statistics. We determine fairly, well the amount produced, but this does not answer all inquiries because of the erratic conditions of mining, it is necessary to carry larger stocks of metals than of most other articles; moreover, as metals are more or less durable, it is difficult to determine the actual consumption. We often count under consumption what is being produced and sold, while the actual consumption is what is being worn out.

Jan 1, 1921

By Stuart St. Clair

In view of the great interest shown in the oil possibilities of Kentucky, one is impressed with the paucity of reliable literature on the oil fields of the state. A few brief reports by the Federal and State Geological Surveys are about the only reliable data available. When the estimated production figures, for 1918, are published by the U. S. Geological Survey, they will show a revival of the oil industry in the Blue Grass State during the past half decade. There will also be an increase in the production for 1919 and 1920, at least. Although as an oil-producing state Kentucky is small, compared with some of the other oil states, the present production and the area of undrilled proved territory is large enough to classify it as one of the important oil states of the Union. This paper will be confined to the Irvine District and the immediately adjoining areas which have been prospected with varying success. The Corniferous limestone or Irvine sand is the oil-producing formation in the area discussed. In my divisional nomenclature, the Irvine District includes the Irvine field, which extends from the town of Irvine eastward toward Campton; the Big Sinking area, which joins and lies to the south of the eastern part of the Irvine field; the Beattyville area, which lies to the north and northeast of the town of that name and joins the Big Sinking area; and the Ross Creek pool, which lies to the southwest of the big production and across the Kentucky River. Except for the Ross Creek pool, the main producing area is bounded on the east by the L. & E. R. R. and on the west and south by the Irvine Branch of the L. & N. R. R. Winchester and Lexington form the gateways and Torrent on the east, Irvine on the west, and Beattyville on the south are the principle entrances to the main fields. Evelyn, on the L. & N. R. R., south of Irvine, is the point of entrance to the Ross Creek area. Geology The geology of the Irvine District is very simple. The rock formations with which the oil man should acquaint himself lie between the lower measures of the Pennsylvanian sandstones and shales and the Devonian or Corniferous limestone, or Irvine formation. Only a very brief description of these formations will be given, as they have been described fully by E. W. Shaw.'

Jan 1, 1921

By C. F. Seaman, R. G. Clay

The mines of The Tennessee Copper Co. are in the Ducktown Basin, in southeastern Tennessee. The ore is a heavy sulphide consisting principally of chalcopyrite, pyrite and pyrrhotite and in places running as high as 95 per cent sulphur and iron. Operating mines are the Burra Burra and Eureka. Development ' of the Boyd ore body was started in 1940. Late in 1939 the decision was made to change from fuse and cap to all electric blasting and at the same time electric cap lamps were installed to replace carbide. These changes were made to improve the safety and working conditions in the mines. Both the Bureau of Mines and explosives manufacturers recommended electric blasting as a safety measure. Until that rime, electric blasting had been used only for shaft sinking and in places where it was absolutely essential for safety. Very few men had had experience in this type of blasting, as the places where it was required were those that also required direct supervision. It was necessary for the mining staff to work out methods, procedure, and equipment to be used. In this they were ably assisted by representatives of the explosives manufacturers. Many mistakes were made and it is the purpose of this paper to describe the original plan and installation, show the major difficulties encountered. the remedies applied, and present the practices now being followed. Comparison of costs of the two methods will also be discussed. About six months were required to make the change and eliminate fuse and cap blasting entirely. The first electric blasting stations were installed in November 1939 and the last fuse was taken underground in May 1940. A very unusual condition forced the use of fuse for a short time in one heading after May, but that will be discussed later. Original Equipment and Installation A power line is generally recommended as a source of current where permanent blasting stations are used. The plan worked out for electric blasting was to tap 220-volt alternating-current lines when they were available and use 250-volt direct current from the trolley wire at all other places. A blasting machine would be available at each shaft for places where there were no regular blasting stations and could be used if a regular station should fail. The equipment decided on was No. 16 duplex reinforced lamp cord for lines to within about 50 ft. of the working place and No. 20 lead wire from that point to the shots. An open double-pole, double-throw switch with slate base was put in the circuit, so connected that the down position would close the line to the shots 2nd the up position would connect it to the Iine from the power contactor. This switch was located in the circuit as close to the blast as was safe (should the shots explode when it was placed in the shooting

Jan 1, 1943

By R. G. Clay, C. F. Seaman

The mines of The Tennessee Copper Co. are in the Ducktown Basin, in southeastern Tennessee. The ore is a heavy sulphide consisting principally of chalcopyrite, pyrite and pyrrhotite and in places running as high as 95 per cent sulphur and iron. Operating mines are the Burra Burra and Eureka. Development ' of the Boyd ore body was started in 1940. Late in 1939 the decision was made to change from fuse and cap to all electric blasting and at the same time electric cap lamps were installed to replace carbide. These changes were made to improve the safety and working conditions in the mines. Both the Bureau of Mines and explosives manufacturers recommended electric blasting as a safety measure. Until that rime, electric blasting had been used only for shaft sinking and in places where it was absolutely essential for safety. Very few men had had experience in this type of blasting, as the places where it was required were those that also required direct supervision. It was necessary for the mining staff to work out methods, procedure, and equipment to be used. In this they were ably assisted by representatives of the explosives manufacturers. Many mistakes were made and it is the purpose of this paper to describe the original plan and installation, show the major difficulties encountered. the remedies applied, and present the practices now being followed. Comparison of costs of the two methods will also be discussed. About six months were required to make the change and eliminate fuse and cap blasting entirely. The first electric blasting stations were installed in November 1939 and the last fuse was taken underground in May 1940. A very unusual condition forced the use of fuse for a short time in one heading after May, but that will be discussed later. Original Equipment and Installation A power line is generally recommended as a source of current where permanent blasting stations are used. The plan worked out for electric blasting was to tap 220-volt alternating-current lines when they were available and use 250-volt direct current from the trolley wire at all other places. A blasting machine would be available at each shaft for places where there were no regular blasting stations and could be used if a regular station should fail. The equipment decided on was No. 16 duplex reinforced lamp cord for lines to within about 50 ft. of the working place and No. 20 lead wire from that point to the shots. An open double-pole, double-throw switch with slate base was put in the circuit, so connected that the down position would close the line to the shots 2nd the up position would connect it to the Iine from the power contactor. This switch was located in the circuit as close to the blast as was safe (should the shots explode when it was placed in the shooting

Jan 1, 1943

By Robert I. Jaffee, Bruce W. Gonser, Eugene M. Smith

THERE has been little investigation of the gold-germanium binary alloys. Haughton1 does not mention any work on the system. In a review article commemorating the fiftieth anniversary of the discovery of germanium, E. Einecke2 mentioned a gold germanium eutectic at 24 atomic per cent Ge (10.4 weight per cent) melting at 359°C., but did not give the source of his information. From measurements of electrical conductivity, J. 0. Linde3 estimated that at least o.6 weight per cent germanium is soluble in gold. The recent availability of germanium in this country in commercial quantities has led to interest in its properties and its alloys. This study is part of a program of investigation on germanium alloys; work on ternary alloys involving germanium and gold will be reported later. In this investigation, the composition and melting point of the Au-Ge eutectic reported by Einecke has been found to be substantially correct. Eutectic composition has been placed at 12,0 per cent germanium, however. An alloy of 10.4 per cent Ge, Einecke's value, was found to have a few gold dendrites in it. The eutectic temperature has been determined as 356.0 ± 0.5°C., slightly less than the temperature of 359°C reported by Einecke. The liquidus curves and the solid solubility of germanium in gold have been determined, and are shown in Fig. I. MATERIALS AND ALLOYING The germanium used in this investigation was prepared by the Eagle-Picher Lead Co. from pure germanium oxide, by reduction in clay crucibles with sodium cyanide. The regulus is quite pure, assaying over 99.9 per cent Ge. High-purity gold obtained from Handy and Harmon was used. Alloying was carried out in graphite crucibles in an atmosphere of purified hydrogen. The temperature was brought up to 1050° to 1100°C., and the metal was allowed to freeze in the crucible. Prepared in this way, the gold dendrites in hypoeutectic alloys were somewhat segregated at the bottom and sides of the ingot, and on the hypereutectic side the lighter primary germanium tended to gather at the top. Most of the alloys were made from virgin metal. Low-germanium heats were made by alloying pure gold with the eutectic. Melting losses were consistently a few milligrams or less, and the composition could safely be taken from the intended analysis. The 30 per cent and 50 per cent germanium heats for thermal analysis were made in part from remelted higher germanium heats, and they may be off composition as much as one per cent. Because of the high cost of materials, the weight of heats for thermal analysis were 15 to 20 grams and heats for metallographic, X-ray, and hardness specimens were 2 to 4 grams.

Jan 1, 1945

By Paul M. Tyler

YEAR after year, the kaolin industry of the United States has been setting new production records and making better products. High-grade paper, pottery, and rubber clays are produced in this country mostly in the South. Georgia alone contributes over 70 pct and South Carolina almost 20 pct of the total domestic output. Residual kaolin is mined in North Carolina, highly plastic but naturally sandy Tertiary (Eocene) potting clays are worked in north central Florida, and good white clays are produced in several other states, but the main sources of kaolin or china clay have been numerous deposits in the Tuscaloosa (Upper Cretaceous) formation. This formation of generally sandy sediments is called the Middendorf member in older geologic reports and corresponds in age with some of the New Jersey clays. As shown in fig. 1, it crops out almost continuously in a generally southwesterly direction across South Carolina and Georgia and into Alabama. Clay is mined from this formation in all three states but the principal producing centers lie within about 10 miles of a straight line drawn between Aiken, S. C., and a point about 10 miles south of Macon, Ga. The white kaolins of the South were recognized and used prior to the Civil War but suitable treatment processes were not introduced until World War I when imports, chiefly from England, were curtailed. Although imports of high-grade clays were resumed after 1918, the domestic industry managed to treble its prewar production record during the early 1920's and has continued to grow. Whereas the 1909 to 1913 average total production in the United States was only 132,104 short tons valued at $705,352 f.O.b. mines, the output in 1948 was 1,-568,848 tons worth $19,756,738. Paradoxically, it seems in retrospect that the early failure of the American industry to meet foreign competition was due to the superior quality of our sedimentary clays in their natural state. Kaolin, of course, is the principal decomposition product of feldspars which originate in acidic igneous rocks such as granite, aplite, alaskite, granodiorite, quartz porphyry, etc. English china clays occur in residual deposits and before they can be marketed they have to be treated to remove accompanying quartz, mica, and other impurities. Notwithstanding the relatively crude methods employed, the final product is a beneficiated clay which is subject to a certain amount of technical control as to quality and uniformity. Although the naturally concentrated deposits in Georgia and South Carolina contain some of the finest crude white kaolin in the world, even it can be made better by suitable treatment. In recent years well over half of the high-grade china clay produced in the United States has been used in making paper. Some qualities of paper clays are still produced by the dry process, or air flotation, but the paper industry's specifications have grown so exacting that wet processing was adopted and more refined methods had to be perfected. Notwithstanding notable advances in clay-preparation technology during the past decade, or possibly because these advances have implemented and encouraged technologic changes in consuming industries, demand has grown for products of higher uniform quality than can be obtained from even the best natural deposits without rigidly controlled fractionation. Largely as a result of the wide adoption of machine coating for paper, the clay industry has been obliged not merely to eliminate virtually all mineral impurities but also to segregate the clay substance itself into narrow particle-size ranges. By extraordinary coordination of sales effort and production technology, several Georgia companies manage to market a wide variety of specialized joint products but the commercial success of many producers depends upon their mining only the best parts of their deposits and then skimming the cream of this almost pure clay in order to obtain a maximum yield of kaolinite finer than about 2 microns in maximum particle size and possessing low viscosity as well as the more familiar attributes of suitable color and brightness, or reflectance. To the casual visitor from another mineral industry, the kaolin mines and plants may appear to be

Jan 1, 1951