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Extractive Metallurgy Division Institute of Metals Division Iron and Steel Division OFFICERS AND COMMITTEES John Chipman, President W R Hibbard, Jr, Past President C C Long, Vice-President T D Jones, Treasurer R W Shearman, Secretary AIME, 29 West 39th Street New York 18, N Y

Jan 1, 1959

EUGENE WESLEY SHAW,* Washington, D. C. (written discussion?).-Mr. Requa's subject is one of great economic importance, yet relatively new, and he has been able to combine extensive practical experience with the talent of grasping the broad features of a problem that has many discordant details.

Jan 5, 1918

By Jacob Reeese

I HAVE discovered a new method by which steel and other metals may be burnished by the automatic action of the burnishing machine, and by which the cost is greatly diminished, and more perfect work produced. And in addition to the polishing and burnishing action of

Jan 1, 1881

By Jacob Reese

I have discovered a new method by which steel and other metals may be burnished by the automatic action of the burnishing machine, and by which the cost is greatly diminished, and more perfect work produced. And in addition to the polishing and burnishing action of

Jan 1, 1881

By A. L. Baxley

An Untapped Energy Resource As much as 20 billion cubic feet of natural gas per day are flared from remote oil fields for lack of a commercially viable means of capturing, transporting, and marketing such gas. The magnitude of these gas flares can be put into perspective from an early satellite photograph (Fig. 1) which shows lights from the major cities of Russia and Eastern Europe dwarfed by the natural gas being flared in the Persian Gulf. Together, these wasted resources contain the energy equivalent of about one-half of the gasoline consumption in the United States today (Fig. 2). Additional trillions of cubic feet of natural gas are "shut-in" because of no economically viable means of commercial recovery. Methanol and liquified natural gas (LNG) are the only two practical fuel products which can be produced economically from these gas supplies. Many of these gas supplies are less than 500 million cubic feet of gas per day, making an LNG facility uneconomic. In contrast, barge-mounted methanol plants can economically convert billions of cubic feet of gas per day into safe, clean-burning methanol. The methanol approach offers the only economical route to transform vast, known reserves of natural gas into a highly versatile primary liquid fuel. Methanol Barges: An Innovative Solution The barges will be towed to suitable offshore and upriver locations such as Alaska, South America, Africa, Southeast Asia, Australia, New Zealand, and the South Pacific Islands, as well as fields in the Persian Gulf and Mediterranean Sea. At the offshore production site, a barge will be anchored by a single point mooring buoy that will also serve as an entry point for natural gas feedstock and an offloading point for methanol (Fig. 3). At some sites the barge would be beached. Each barge will produce methanol and store it in internal tanks with a capacity of 18 million gallons. The methanol will be offloaded into conventional tankers and safely transported directly to market. Unlike LNG, methanol requires neither specially built carriers nor specially built receiving terminals. Once a particular gas field has been exhausted, the barge will be towed to another location to continue production. Each barge will measure 320 by 500 ft, approximately the size of four football fields, and will have the capacity to produce 1 million gallons or 2800 metric tons of methanol per day, from approximately 100 million cubic feet of natural gas per day (Fig. 4). The barges will use the highly successful "low- pressure" design developed by the Lurgi Company of Germany, a process proven in land-based methanol plants throughout the world during the last ten years. The decision to use Lurgi technology for "sea-trans- portable" methanol plants was based on the higher efficiency and greater operability of the technology compared to other commercially proven processes. The conversion plant will be designed to accept a wide variety of feed gas compositions, and will produce chemical-grade methanol for the broadest market base (Fig. 5). To minimize costs and construction time, the barge-mounted plants will be built in the high technology environment of a domestic or foreign shipyard. Selection of the construction site for each barge will be dictated by the location of the production site and by the relative construction costs. A number of shipyards have the capacity to build several barges per year. The detailed marine engineering to integrate the design of the processing plant with the floating platform can be performed by numerous major engineering companies around the world. Production Economics The barge-mounted plant concept not only assures large volumes of methanol, but it also keeps the overall production cost low by minimizing construction cost and providing access to low cost natural gas feedstock with no alternative or a negative value. Together, these advantages make the barge-mounted methanol plants economical today. The cost structure of a new barge-mounted methanol plant differs from that of existing methanol producers around the world (Fig. 6). For example, if a U.S. Gulf Coast producer is paying $4.70/MMBtu in 1985 for natural gas, the barge plant could afford to pay about $1.6O/MMBtu for gas and be able to deliver methanol to the Gulf Coast at the same price. At some future date such as 1990, a gas cost of $6.70/MMBtu for a domestic producer would have cost parity with about $3.60/MMBtu gas cost for the barge plant. In many foreign markets, feedstocks other than natural gas are used for methanol production (Fig. 7). For example, most of Japan's capacity is based on LNG while Western Europe uses residual oil or naptha. Because these feedstocks are substantially more ex- pensive than natural gas used by U.S. producers, the barge plants will compete even more favorably in these foreign markets. As crude oil prices rise, the value of methanol in each of these markets will increase. However, the hierarchy of methanol values in these markets should remain unchanged. Furthermore, the cost advantage for using methanol in these markets will improve as world energy costs increase since the value of remote gas should not escalate significantly.

Jan 1, 1982

By K. S. Benson

DEPLETION is a subject of vital importance to the mining industry. Yet, in spite of its importance, its significance is not generally understood. The purpose of this discussion is to clarify the main aspects of the subject from the viewpoint of a metal mine taxpayer. To define the term depletion, it is necessary to distinguish among its various uses. In the economic or geological sense, depletion means the exhaustion of a natural resource. A mineral deposit is a wasting asset and once exhausted is nonrenewable. Millions of years were needed to produce an ore deposit, which may be consumed in a few years and which cannot be replaced except by the discovery of new sources of supply. The wasting asset feature of the mining industry has a vital bearing on the impact of the Federal Income Tax Law on this industry. This is recognized in the law by the various provisions dealing with the depletion allowance, and in this sense the term depletion has an income tax meaning. Depletion from the tax viewpoint means the statutory deduction from gross income designed to permit the return to the taxpayer of the capital consumed in the production and sale of a natural resource. The mining enterprise realizes income on the extraction and sale of minerals and a portion of the income realized represents capital consumed. As the resource is exhausted, the mining enterprise approaches the end of its existence unless new sources of supply can be acquired. Depletion from the tax viewpoint is a creature of statute with limited meaning and application and, in essence, is a method for amortizing the value of the primary asset of a mining enterprise. An example can best illustrate the significance of depletion from the tax viewpoint. Compare a manufacturing concern with a mining company. In computing taxable income of a manufacturing concern, consideraion is given to the cost of producing such income, the principal costs being capital investment for plant and equipment, labor, and raw materials going into the products produced. A mining enterprise, on the other hand, is faced with a different problem because its principal asset is the natural resource which it is producing. In computing its taxable income, consideration is given also to its capital investment for plant and equipment and the cost of labor; but in addition, recognition must be given to the fact that a portion of the proceeds realized on the sale of mineral represents capital. Without such recognition, the mining company would be taxed not on income but on capital and income, and Congress has never intended that capital be taxed as income. Thus, when depletion allowable is referred to in the mining industry, it means the statutory deduction allowable in computing taxable income of a mining enterprise. For guidance the appropriate provisions of the Internal Revenue Code, Income Tax Regulations, and the judicial decisions interpreting and construing them must be examined. It is important to identify and distinguish three methods of determining the allowance for depletion: 1—Cost depletion, 2—Discovery depletion, and 3—Percentage depletion. The basic method is cost depletion and in addition some taxpayers may be entitled to use discovery depletion and other taxpayers may be entitled to use percentage depletion. Discovery depletion and percentage depletion, however, are mutually exclusive and if a taxpayer is entitled to percentage depletion, he is not entitled to discovery depletion. By statute, a metal mine taxpayer is entitled to use cost depletion or percentage depletion, whichever produces the highest deduction. Thus, discovery depletion is merely of academic interest to such taxpayers and to most others. Briefly and broadly speaking, these methods of determining depletion may be described as follows: 1—Cost Depletion: Under this method, the allowable deduction for depletion is based upon the cost of the particular deposit to the taxpayer, unless the deposit was owned prior to Mar. 1, 1913, in which case the taxpayer may use the fair market value of the deposit on that date or actual cost, whichever is higher. This method is sometimes described as basis depletion or adjusted basis depletion, but in this discussion it will be referred to as cost depletion. 2—Discovery Depletion: Under this method, the allowable deduction for depletion is based on the fair market value of the deposit at the date of discovery or within 30 days thereafter and was originally designed to take into account deposits discovered subsequent to Feb. 28, 1913. 3—Percentage Depletion: Under this method, the allowable deduction for depletion is based on a specified percentage of the income realized during the taxable year from a particular property. As stated, the concept of depletion is based upon the exhaustion of a natural resource as distinguished, for example, from the concept of depreciation based on the exhaustion of property used in trade or business. From the tax viewpoint, depletion first became important in the administration of the Corporation Tax Act of 1909, which provided for an excise tax on net income. As soon as this act went into effect, mining taxpayers attempted to claim a deduction for depletion in computing net income although there was no specific mention of a deduction for depletion in the statute. The courts in these cases uniformly held that the statute did not permit an allowance for depletion in computing net income and also held that the provision permitting a reasonable allowance for depreciation did not include depletion. These early cases are quite significant because they establish the principle that the

Jan 1, 1952

R. V. Norris, Wilkes-Barre, Pa. (communication to the Secretary*):—Mr. Stow's paper presents a series of arguments, numbered from 1 to 18, concerning the relative merits of four systems of colliery-ventilation, designated by the author as " plain pressure-ventilation," " plain exhaust-ventilation," " obstructed pressure-ventilation," and " obstructed exhaust-ventilation." These arguments are subsequently compared by means of tables, in which an arbitrary numerical value is assigned to each, and which consequently serve no other purpose than that of showing his opinions and predilections, as indicated by his assignment of the said numerical values. In addition to this general summary, Mr. Stow intimates his preference for a fifth method of colliery-ventilation—namely, what he calls " alternating pressure-ventilation," which consists in the running of the fan at "pressure " during working-hours, and as an " exhaust" between shifts—a system which he proposes as, perhaps, new, yet which he thinks deserves recognition " as a standard form." This proposed " standard form " is not to be found in practice ; and I think it would be impracticable in gaseous mines of large extent, for the following reasons: 1. It takes considerable time to reverse the air-current in a large mine; and the reversal would involve a period of complete stoppage of ventilation, long enough to permit serious accumulations of gas. 2. In shaft- and slope-mines, at least, it is hardly practicable to have " every man out of the mine" during the night, and certainly impracticable to avoid keeping mules and horses inside. 3. The doors necessary to divide and direct the air-current are properly hung to open against the air-pressure; and, unless

Jan 1, 1910

By T. S. Lovering

GEOCHEMICAL prospecting extends the age-old method of searching out lodes with a gold pan and rationalizes the prospector's hunch that certain plants are associated with ore. It uses sensitive but cheap and rapid analytical methods to find the diagnostic chemical variations related to hidden mineral deposits. Exploration geologists can gain tremendous assistance from this new tool, although its optimum use is not simple. To bring out the geochemical pattern that reveals the presence of a hidden ore deposit with a minimum number of samples requires a combination of shrewdness, chemical knowledge, and exploration geology. The use of sensitive analytical methods for prospecting had its start in the 1930's in northern Europe, where Scandinavian and Russian geologists had some success in these early efforts. Very little geochemical prospecting was carried on in the United States at this time, and no sustained interest was manifest until the close of World War 11, when geochemical investigations were started by the Mineral Deposits Branch of the U. S. Geological Survey. The purpose of these investigations was to apply geochemical principles and techniques to surface exploration for mineral deposits. Both the research on analytical methods and the routine trace analyses for field investigations were at first conducted by a single group, but it later became apparent that the trace analyses could be done by men of less experience than that required for successful research on methods. For the past several years there have been two groups of chemists, and although their functions overlap, three of the chemists are chiefly concerned with research, while four to six other men make the trace analyses for field projects. The chemical investigations, as well as the field projects of the Geochemical Exploration Section, concern only those phases of the subject that are appropriate to a government organization; every effort is made to help private industry, but not to compete with it, in finding orebodies. The chief aim of the Section, therefore, is to develop new analytical techniques and publish the results promptly, to carry out field investigations of the fundamental principles of geochemical dispersion, and to field test promising- techniques under controlled conditions. Some routine geochemical exploration work is carried on in connection with DMEA loans, and in district studies where the project chief wishes geochemical information on certain areas for his report. It should be emphasized, however, that geologists of the Geochemical Exploration Section are primarily concerned with fundamental principles underlying the distribution, migration, and concentration of elements in the earth's crust. To facilitate the use of geochemical methods the USGS has published much information on its methods of analysis and has provided opportunities from time to time for qualified professional personnel to study these methods, to work in the USGS laboratory, or to attend demonstrations of the analytical techniques at the Denver Federal Center. Typical of the research carried on are the problems now being investigated: 1) Development of rapid and sensitive analytical methods suitable to the determination of traces of metals and other minor elements in various materials, such as rock, soils, plants, and water. At the present time attention is being concentrated on U, Bi, Cr, and Hg, and satisfactory rapid trace analytical methods are virtually perfected for U and Bi. Good methods are also available for: Cu, Zn, Pb, Ni, Co, As, Sb, W, Mo, Ag, Nb, Ge, V, Ti, Fe, Mn, S, and P. 2) The relation of geochemical anomalies in plant materials to the geochemical distribution of elements in soils surrounding the plant. 3) A study of the dispersion halos in transported sedimentary cover such as glacial drift and alluvium over known orebodies. 4) A study of the behavior of ore metals in the weathering cycle. 5) A study of the behavior of the ore metals during magmatic differentiation. This requires a study of the distribution of minor metals in fresh igneous rocks and their component minerals in a well established differentiation series and in adjacent country rock. 6) A study of the dispersion of metals in primary halos in the wall rock surrounding orebodies. 7) Regional and local studies of the metal content of surface and groundwater in mineralized and barren areas. Many field projects of the Mineral Deposits Branch also require the services of USGS chemists during their investigation of the geochemical environment of ore deposits. From the work that has been done certain general principles have emerged. Concentrations of an element that are above the general or background value of barren material are called positive geochemical anomalies or simply an anomaly, whereas values less than background are called negative anomalies. The anomalies most commonly investigated in geochemical prospecting are those formed at the earth's surface by agents of weathering, erosion, or surficial transportation, but more and more attention is being given to primary anomalies found

Jan 1, 1956

By W. J. McKenna

The International Smelting Co. concentrator at Tooele, Utah, first operated on a custom basis for the treatment of lead-zinc-iron ores on Nov. 1, 1924, with a capacity of 500 tons per day. On May 1, 1925, the capacity was increased to 1000 tons per day by the addition of another 500-ton section. The concentrator has since operated on the two-section basis, each treating 500 tons per day entirely by flotation. Laboratory and Test Mill In connection with the concentrator, a well-equipped laboratory and small continuous testing plant are maintained. The flotation equipment in the test plant is of both the Callow and Mineral Separations Sub-"A" types, so that actual concentrator conditions may be duplicated as closely as possible. Purchasing of Ore A new shipper usually sends to the plant a 25 to 50-lb. samplc, representative of the ore to be shipped. Batch flotation tests are made on this sample to determine its amenability to the concentrator treatment flowsheet and reagent combinations. The results of these tests, which are accurately correlated with those obtained at the concentrator, both as to grades of products and recoveries, determine the actual value of the ore as submitted in the ore purchasing department's treatment schedule. Hearty cooperation has existed at all times between the ore purchasing and operating departments in the selection of ores as conccntrator feed. Ores Treated The basic tonnages for mixtures on the two sections come from the Park City and Bingham mining districts. The Park City tonnages arc received by rail and consist of crude ores and gravity mill products. Those from the Bingham district arc received by rail and aerial tramway,

Jan 1, 1928

By Robert H. Richards

My first paper, read at the Cobalt Meeting of the Institute,' July, 1907, dealt with the behavior of a small Wilfley table when collceiltrating galena from quartz, the table being fed with natural products, with sized products, and with classified products. Since galena, having a specific gravity of 7.5, is among the heaviest minerals ordinarily concentrated by Wilfley table, it was desirable that a similar set of tests upon a mineral of lighter weight should be made. Chalcopyrite, of a specific gravity of 4, would have been the best mineral for this purpose, on account of its great importance as an economic mineral, but in carrying out the test I was obliged to content myself with a cupriferous pyrite, the specific gravity of which was 4.68 and the content in copper 8.80 per cent. Through the kindness of H. 0. Cummins, this material was obtained from Shasta, Cal., in very pure, clean, homogeneous condition. It was broken by rolls to 2 mm. in size, taking care to make a minimum of slimes. The quartz used to mix with it was pure, white, New England quartz, broken in the same way to the same size. In studying the accompanying tables, it should be borne in mind that the material concentrated was of low copper-content, and in many cases the quantity fed to the machine was 1 kg. or less. As a consequence of the smallness of the quantity treated it was very difficult to adjust the table and get it in condition to do its best work before the feed became exhausted, and for this reason many results were obtained which appear irregular.

Jan 1, 1909

By D. H. Wertz, R. R. Furlong

Dry room equipment at Donora Zinc Works is of the design which prevailed at the time the plant was built in 1915. It consists of 11 adjoining rooms, each being 99 ft long, 11 ft wide, and 7 ft high and having a capacity for 1040 retorts. Heat is supplied by steam coils beneath the slatted wood floor and by warm air ducts at the ceiling. Drying practice is about the same as that generally followed in the industry except that, under normal zinc furnace operations, the maximum drying time is 45 days. During certain seasons of the year the drying process was seriously affected by varying weather conditions which frequently resulted in a scrap loss of 5 to 7 pct. Because of these unfavorable conditions, which caused uneven drying and strains in the retorts, increased retort failures in the zinc furnaces were recorded. Regulation of temperature and humidity under all conditions appeared to be the logical solution of this problem. Controlled drying had been developed for a number of ceramic products and investigation of several such drying processes in this area revealed favorable results. Along with control of drying conditions and the attendant decrease in scrap losses, plant operators also reported a material reduction in drying time. Another factor affecting the decision to proceed with this development was the drastic change in market conditions for retort clay. Curtailment of shipments from the chief source of supply made it necessary to proceed with blending of other available clays, but quality of these clays was questionable for adequate retort life in the 24 hr furnace cycle. Rapid furnace testing of new mixtures was desirable but impossible with the prolonged drying schedule. Therefore development of a controlled drying process for zinc re- torts offered the solution to the problem of rapid testing of retort mixtures. Description of Process and Equipment The freshly extruded retort is cylindrical in shape, 58 in. long, 9 in. id and has 1 1/8 in. side walls. One end is closed and approximately 2 in. thick. The moisture content of this "green" retort is about 17 pct which means a necessary removal of 30 lb of water per retort. Retorts are set on the slatted floor of the dry room with the closed end down. The controlled drying process depends upon the circulation of a large volume of conditioned air at low velocity. To provide for uniform distribu-

Jan 1, 1950

By Foster Bain

MOST of us householders in the East burn anthra-cite, so the problem that interests us most is the distribution and supply of the domestic sizes of anthracite. That, however, is only a small part of the coal problem and has its own peculiarities. Whether anthracite prices are high or low is largely a matter of relativity, depending on the size of the transaction, the available supply, and other things. As an isolated example which I hesitate to quote because it is not entirely representative, you may be interested to know that the Government fuel yard has been delivering to the Government buildings in the District of Columbia, white-ash stove coal at 16 c. a ton less during January, 1923, than during the same month of 1922. The reason is that the Government deals only with large companies who have been wise enough not to boost their prices and the small increase at the mine has been more than offset by the decrease in railroad rates. The total cost is $12.50 per ton, but I want to make it perfectly clear that it does not follow that this would be a just price for a retail dealer to charge the domestic consumer. For example, in the Government business there is no such thing as a bad debt, and certain other fixed or general charges are charged to other departments. The Bureau of Effi-ciency made an effort to determine what would be a. legitimate handling charge for a retail dealer, in Washington, and concluded that if the Government's cost of handling was $1.00, then $1.88 would be the corresponding fair charge to pay a retail dealer carrying the same volume of business, allowing for bad debts, complete depletion and depreciation of his equipment, and 10- per cent. profit. Assuming that this is the correct differential for Washington, it does not' follow that it would be equally just for Pittsburgh, New York, or elsewhere; nor does it by any means follow that it is a fair differential this year, because the dealer, after being unable to use his equipment in the summer months, now has to deliver an unusually large quantity of coal. I merely cite this instance to show that on the basis of primary cost of coal plus railway charges the retail price is not necessarily higher this-year than last.

Jan 4, 1923

By L. D. Jaffe, John H. Hollomon

Fox many steel parts it is desired to obtain the maximum toughness consistent with the strength required by the mechanical design. It is generally recognized that the greatest toughness at any given strength is found in steels having a tempered martensitic structure,1 and is virtually independent of the composition of the steel2 (except for carbon). The choice of the composition of a steel for the parts in question should be based, therefore, on hardenability considerations and on manufacturing facility and economy. In a recent paper3 the concept of hardenability was discussed and a somewhat new approach to the problem was suggested. The hardenability was defined in terms of the cooling conditions (speed of cooling) required to avoid the pearlite and the bainite reactions. Since all the alloying elements do not have the same effects on the two reactions, the bainitic and pearlitic hardenabilities must be considered separately. In order to design a steel for a given part, it is necessary to design a composition that has both sufficient pearlitic and sufficient bainitic hardenability. However, this requirement does not fix the combination of alloying elements to be used; an infinite number of steels would have the required hardenabilities. Other considerations limit the choice. For example, decreasing the carbon content increases the toughness at a given hardness, and for this reason low-carbon steels are often desired. Limitations or requirements of refining, casting, or forming practices often affect the level of some of the alloying elements. Price considerations enter. Frequently, however, it is very desirable to minimize the tendency toward quench-cracking while maintaining the necessary hardenability. This paper is concerned with suggesting a method for choosing compositions that will have the required hardenability together with minimum tendency toward quench-cracking. QUENCH-CRACKING Since only the case in which the entire part will transform to martensite in the particular quench employed is being considered, the analysis of the quench-cracking problem is somewhat simplified. Quench-cracking arises from the temperature gradients existing throughout the piece during cooling. Because of these temperature gradients, the contraction arising from the decreasing temperature and the expansion arising from the austenite-martensite reaction do not occur uniformly over the parts, and stresses are set up that tend to cause cracking. The temperature gradients can be reduced by decreasing the severity of quench. This, however, requires that the hardenability be correspondingly increased by increasing the carbon or alloy content. An

Jan 1, 1946

By I. H. Pratt

The results of a study on the preparation of thin-film capacitor structures are discussed. The dietectric source material was quartz which was sputtered and deposited onto aluminum electrodes and counter-electroded to complete the metal-oxide-metal structures. This configuration was utilized to evaluate the dielectric, the device characteristics, and related process parameters. The effect of gas sputtering pressure, magnetic field strength, source-to-substrate distance, and power density on the rate of deposition is shown. Increased film thickness uniformity over a 3 by 3 in. area by optimum substrate positioning is indicated. Dielectric constant, dissipation factor, dielectric breakdown strength, insulation resistance, heat treatment, capacitance, and dissipation over the range 400 Hz to 5 MHz are reported. In the fabrication of silicon-integrated circuits, silicon dioxide has found use as a material suitable as a diffusion mask, for surface passivation of the silicon, and for protection of conductive films used for interconnections. Its use as a dielectric for thin-film capacitors in film hybrid circuits has been limited, to a degree, for lack of a compatible processing technique and because of its relatively low dielectric constant. With the recent advent of practical metal-oxide-semiconductor (MOS) field effect devices, the material is now being used to insulate the gate electrode from the conducting channel in the silicon. In this latter application, more stringent requirements have been imposed on .the oxide. A comprehensive resume of the use of silicon dioxide in integrated silicon device technology has been compiled including oxide film and bulk properties, method of oxide formations, and their applications.' A relatively new process to deposit SiO, and other dieIectrics is by rf sputtering, and the purpose of this paper is to describe the behavior of capacitors fabricated with a dielectric which has been sputtered from a quartz target and to indicate the relative effect of several of the process parameters on the film deposition. Work on rf sputtering of SiO2 and other dielectrics has been reported utilizing a triode type of sputtering system as described herein or a diode self-sustained glow discharge system. 2-8 SPUTTERING The process occurs during an electrical discharge in a gas plasma which provides the ions for acceleration to the target to produce the desired sputtering. The necessary plasma can be generated by a dc glow discharge through application of a high potential between two electrodes at approximately 2 to 10 x 10-2

Jan 1, 1969

By Galen H. Clevenger

Equipment for treating lead ores was added in 1905 to a copper plant which the United States Smelting Refining and Mining Co. had built in 1902 at Midvale, Utah, about 12 miles to the south of Salt Lake City. By 1906 the lead section of the plant had been rounded out and consisted of a 90-ton gravity concentrator, fifteen hand-rabbled reverbera-tory roasting furnaces, six blast furnaces, a briquetting plant for handling flue dust and fine ores, a regulus furnace for concentrating the low-grade matte made in the blast furnaces, and a baghouse. The copper section was later abandoned and the plant has been operated for many years exclusively as a lead smelter. Some 45 years had elapsed at the time this plant was built since the first attempts to smelt lead ores in the West, and lead smelting had become a large and profitable industry but fundamentally little that was really new had been developed, which could be embodied in a plant built in this period. Principles and tools to work with had remained much the same as those borrowed earlier from European practice. Capacities had been increased and there were mechanical improvements but hand charging was still in vogue and there was little attempt to recover suspended particles carried out with the furnace gases, beyond settling in flues, which usually was only partly effective for recovery of the coarser particles. Satisfactory roasting and preparation of the fine components of the charge were still partially solved problems. The Midvale plant of 1906 may be regarded as more or less typical of the smelting plant of this period for treating complex western lead ores as distinguished from the recovery of lead from the simple lead ores to the eastward. The operation of a concentrating mill directly in conjunction with a lead smelter was, however, not common practice. The ores treated in this plant have from the beginning come from mines owned and operated by the company or have been custom ores purchased in the territory tributary to the plant. The treatment of custom ores is an important service to the small producer who does not have sufficient tonnage to warrant a plant, and serves to increase the tonnage of the operator of large properties, thereby helping to reduce

Jan 1, 1937

By C. W. Stratford

[During the last few years, the necessity for development work has been generally recognized by executives throughout the oil industry, resulting in greatly accelerated progress and the adoption of many noteworthy improvements in refining methods and equipment. Several years ago, the Associated Oil Co. decided to improve distillation methods with the object of reducing refining costs. This extremely interesting work was entrusted to the writer, and W. S. James, now Chief of Research for Studebaker Corpn. of America, was selected as the principal collaborator. The latter contributed much during his two years with the Associated Oil Co., to the development work that has followed. The writer extends to the Associated Oil Co. his appreciation for permission to disclose the details of distilling equipment. In petroleum refining the principal requisites of good economics are the separation of high-priced distillates from those of lower price; maxi-mum yield of any desired distillate; lowest capital investment in refining equipment; lowest cost of operation and maintenance, and the best adaptability and flexibility of the same refinery equipment for handling crudes of widely varying characteristics. The first two items mentioned, separation and yields of distillates are determined by efficiency of fractionating equipment,. Discussion in this paper is chiefly concerned with oil-heating equipment, combustion and furl economy. It has long been well known that velocity plays a very important part in all heat transfer systems. Any betterment in specific transfer. rates in such systems must. always involve velocity. Realizing this fact, IV decided to adopt as a basic principle, the employment of energy to impart velocity required for high transfer rates through a heating diaphragm, and our method of modernizing obsolete shell stills is founded on this principle. Mechanical energy is usually cheap and its rational rspcntliture is returned in the form of greatly increased heat transfer rates, on both oil and gas sides of the sheet. Certainly there is nothing new in this principle, the only novelty being that of our peculiar method of application On the oil side (Fig. I) use is made of a centrifugal pump to jet the oil against the heated sheet thereby creating a high velocity sheet flow over the entire fired area. Such a pump is one of the most efficient machines, so far developed, for moving fluids. 'I'he oil, under pressure impinging

Jan 1, 1928

Steps were taken for a permanent organization of the scientific and technical employees of the Government at their mass meeting on May 8. This was the result of an informal meeting on Apr. 23 of thirty representative Government scientists and technical men who organized the preliminary committee and called the mass meeting. This subject has been widely discussed during the last year and was brought acutely to the fore by the work of the Joint Congressional Reclassification Commission, because that Commission has stated that it wished to deal with employees only through organizations. Rodney H. True of the Department of Agriculture was Acting Chairman. He pointed out that the principal advantages that were expected to be derived from such an organization were: (1) Improvement of conditions and facilities for more effective scientific and technical work; (2) adequate presentation of the needs. and results of such work to the public and to legislative and administrative officers; (3) -greater freedom in both official and non-official activities; (4) just and reasonable salaries based on service performed and the economic and social conditions which prevail; (5) greater public recognition of the aims and purposes of research; (6) advancement of science and technology as an essential element of national life. Three plans of organization were offered to the meeting, which covered the fundamental principles which could be utilized by these Government employees. The first plan would have permitted the new organization to work only through existing scientific organizations. This is the plan that scientific and technical Government employees in England have adopted and an outline of the English plan was read to the meeting.

Jan 6, 1919

The Fifth Annual National Exposition of Chemical Industries will be held in Chicago at the Coliseum and First Regiment Armory during the week of Sept. 22. It was decided to hold the exposition in Chicago, this year, for two reasons: The U. S. Army commandeered the Grand Central Palace Exposition Building in New York, immediately on the close of the last exposition and converted it into a receiving hospital, the use for which is now, happily, nearly ceased; and it was thought that the Exposition would succeed in bringing about a greater development of chemical industries in the Chicago district and the adjoining states. The Advisory Committee of the Exposition consists of: Charles H. Herty, Chairman, Editor Journal of Industrial and Engineering Chemistry; Raymond F. Bacon, Director, Mellon Institute; L. H. Baekeland, Member Naval Consulting Board; W. D. Bancroft, President, American Electrochemical Society; Henry B. Faber, Industrial Filtration Corpn.; Ellwood Hendrick, President, The Chemists' Club; Bernard C. Hesse, Chemist, General Chemical Co.; A. D. Little, President, Arthur D. Little Inc.; Wm. H. Nichols, President, American Chemical Society; R. P. Perry, Vice-president, The Barrett Co.; H. C. Parmelee, Editor Chemical &; Metallurgical Engineering, G. W. Thompson, President, American Institute of Chemical Engineers; T. B. Wagner, Vice-president, U. S. Food Products Corpn.; M. C. Whitaker, President, U. S. Industrial Chemical Co.; and Charles F. Roth and Fred W. Payne. There is also added a special Chicago committee consisting of L. V. Redman, W. D. Richardson, A. V. H. Mory, Carl S. Minor, F. W. Willard, and Wm. Hoskins; the managers, as in the past, are Charles F. Roth and Fred W. Payne.

Jan 6, 1919

By W. E. Gaby

THE form of dip chart here presented for the use of the profession was devised by the author when he was confronted with a particularly heavy job of geological section making and. did not have any of the usual tables or charts at hand. This was at the property of the Teziutlan Copper Co. in Puebla, Mexico, where the orebodies are much faulted and lie conformably with a slightly inclined and. much folded schist. Because of the low dip and the folding of the orebodies, the engineering, and geological data respecting them were best represented on vertical cross-sections quite closely spaced. A less finished form of the chart was published in the Mining & Scientific Press of Aug. 6, 1921, with an explanation of its use. I have checked the new drawing for accuracy against the calculated table given, and constructed an explanatory diagram beneath. As some geologists are accustomed to using the table, I have included it, since no advantage is obtained by mere interpolations from the chart to get the required angle, except as it gives a mental picture of this angle. The chart gives a more rapid and much easier solution when cases multiply so that it becomes desirable to eliminate the tedious manipulations of a separate protractor. In fact, using the parallel ruler as des-cribed, it is not even necessary to make note of the angle sought. It is brought out graphically, leaving the mind free to note the correlations. The chart itself may be made more convenient by reproduction on celluloid with a slot running on the zero line of the protractor.

Jan 9, 1922

By J. H. Slater

THERE is nothing particularly new about the use of sinter in a blast-furnace burden. For many years flue dust has been sintered at the various blast-furnace plants to put it in a form that could be recharged to the furnace with some assurance that it would stay in the second time. This paper is not a compilation of scientific data but only an attempt to give our experience with sinter. There are some unexplained discrepancies in the tests given here, such as the flue dust produced and iron tonnages, but the results given are the results that were obtained. Sinter is not the cure-all for blast-furnace problems. A good coke is still the most important factor in good furnace operation. However, good sinter is a big help. As flue dust is produced under varying operating conditions and fluctuates greatly in carbon content, it is difficult to produce from flue dust alone a uniform sinter, which will give satisfactory blast-furnace results. Sinter made from flue dust alone will change in character with every carbon variation. Almost invariably flue dust con-tains carbon in excess of the amount necessary to make good sinter, and this excess must be burned out, This, of course, necessitates reduction of the speed of the sintering machine and thus a decrease in tonnage, An alternative is to dilute with a carbon-free material to use up the excess carbon. High-carbon material when sintered results in a very dense, undesirable prod-uct, since the excess heat melts the charge into a hard, nonporous mass, and tends to form refractory silicates.

Jan 1, 1940