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By Lillian Erskine

WHILE brass and other copper alloys have long been listed as offering health hazards to their workers, it is questionable if the metals involved are alone responsible for the trades' records of morbidity. The entire science of foundry sanitation is the product of the past two decades; and the best standards now operative would have been regarded as little short of revolutionary prior to 1910. The special handicap to the conservation of the health of the brass founder's employees has been the fact that, unlike the iron founder, his business could be profitably carried on in almost any small and unsanitary quarters. As a result, writers on occupational disease have accepted brass chills or brass founders' ague as an inevitable feature of the trade; and respiratory disabilities, as well as phthisis and disturbances of the nervous system, are also included as prevalent among those employed. While there can be no question as to the basic accuracy of past investigations, there is every reason to doubt the necessity for an undue percentage of ill health among brass molders and casters who are safeguarded by scientific ventilating standards and by improving personal habits of sobriety. There is, however, need for a campaign of education as to the most approved practices and equipment whereby the employer may safeguard the health of his workers, and thereby reduce his labor turnover and increase his productive efficiency. Broadly speaking, copper, tin, and aluminum carry negligible health hazards. The toxic qualities of lead, however, are a menace; especially if scrap lead is recovered or bought for foundry processes. The rapid volatilization of zinc renders its fumes and flocculent condensation the chief problems in conserving the health of the brass worker. The frequent presence in the foundry air of traces of arsenic compounds, lead

Jan 2, 1919

By William C. Peters

The experiences of exploration crews with mineral land acquisition could be graphed to show a correlation with the natural law that everything tends to become more so. A single step, such as that of taking a series of deep soil samples, is sometimes delayed until some sense can be made from floating unpatented claims which are obscure in orientation as well as position-placer claims, overlapping lode claims, location posts with empty Prince Albert cans and claims with no apparent assessment work for ten years. Add to this some patented claims without monuments, a state or federal withdrawal area which may or may not invalidate preexisting claims, a loosely defined tunnel site, and some ranchers who understandably resent the separation of surface rights from mineral rights.

Jan 1, 1970

By P. A. Boeck

The thermal insulation of high-temperature equipment for industrial purposes is a subject that has not received from engineers and designers the attention its importance deserves. This may be attributed to a number of causes: In the first place, heat flow is a rather difficult factor to measure under the working conditions of an industrial furnace, and until the comparatively recent introduction into certain operations of the heat balance sheet, with a systematic attempt to account for the discrepancies in the totals, the various causes of heat losses and the reasons for their existence were not brought to light. Moreover, such rapid advancement and radical changes in the design of equipment, especially in metallurgical lines, have occurred that practice has apparently outdistanced the theory of design. In the modern tendency toward greatly increased size of units, effort has seemingly been made to utilize the heat of fuel gases without proper attention having been paid to conserving heat energy and confining it strictly to the points of maximum activity. The systematic study of the thermal properties of structural materials, which is being carried out by various government bureaus and also by a number of technical societies, is forming the basis for more intelligent and consistent work in the economically important subject of prevention of fuel waste. Advantages of Insulation It is not necessary in this practical and utilitarian age to enlarge upon the need of prevention of heat losses, but attention may advantageously be called to the other benefits derived simultaneously with the saving in fuel and the increase in thermal capacity of furnaces when properly insulated. In most industrial furnaces—which are here spoken of in the broadest sense, indicating general high-temperature equipment for any purpose and heated in any manner—the operations are generally carried on through a temperature range which has been found by practice to give the most ef-

Jan 1, 1916

By Roland Kammel, Takeo Oki

A suspension electrolysis method has been developed which enabled a direct anodic extraction of zinc from zinc sulfide concentrate and simultaneously oxidized sulfide sulfur to elemental sulfur. The investigation was performed in a laboratory-scale electrolytic cell, where the zinc sulfide concentrate particles (chemical composition in weight percent: 61.1% Zn, 2.3% Fe, 30.6% S, 3.4% SiO2 were suspended with or without graphite powder in a dilute sulfuric acid electrolyte. The main parts of the cylindrical electrolytic cell are shown in [Fig. 1]. The cathode (1), a rod of aluminum, is set at the center of the cell. The anode (2), which consists of four plates, is mounted on the inner face of the cell wall. Both PbO2(Pb) and graphite anodes were used. The cathode compartment (3) is separated from

Jan 1, 1976

By W. N. Logan

A survey of geological conditions, production and prices in Indiana oil fields. Shows no production and indefinite prospects from the sub-Trenton formation; good production and much untested territory in Trenton formation; and fair production from the Pennsylvanian with fair prospects for the future in both the Pennsylvanian and Mississip-pian formations. THE petroleum industry of Indiana made somewhat notable progress during the year 1923, considering the number of handicaps it encountered. The price of labor and materials continued to have an upward slant while the price of crude oil took a decidedly downward course. In spite of these adverse conditions, the quantity production will closely approximate that of 1922, when it passed the million-barrel mark. The progress of the industry in Indiana should be considered fairly satisfactory as long as the present production is maintained. In other words, if the loss of production from the waning old wells can be offset by the production from the new for a period of 10 or 15 years longer, the industry may have cause for congratulation.

Jan 3, 1924

By R. T. Bayliss

Although every mill-man of even limited experience in the amalgamation of gold-ores is probably aware that copper plates will in time become coated by the accumulation of gold-amalgam, it may be that many do not know to what extent this accumulation occurs in the treatment of ores dissimilar to those with which they are familiar, and under conditions foreign to those with which they have to contend in any given locality. The writer, therefore, feels relieved from the necessity of offering an apology for dealing with such an elementary subject, believing that certain facts in reference thereto, which have recently come under his personal observation, will be interesting to many, and possibly instructive to some persons engaged in the amalgamation of gold-ores. The facts hereinafter stated were observed in the 50-stamp "combination"-mill, owned by the Montana Mining Company, Limited, of England, operating the Drum Lummon mine, situated at Marysville, Montana. The material treated in this mill consists of quartz and ores of somewhat variable character, containing gold and silver in native form, as well as in chemical union with the sulphides of iron and copper. There is also present a little lead, some arsenic and antimony, and a little zinc. The last fair minerals, however, are of irregular occurrence, and but sparingly distributed throughout the ore, and yield only a trace in the analysis of the average material in this mill. The free gold, which is in a condition of fine division, and rarely visible to the naked eye, carries silver as an alloy; and the native silver, which is only occasionally observed, is present in the richer ores in wireand in leaf-form. Of the two precious metals, the ore worked during the past three years and ten months, the period under review, contained about 1/2-ounce of gold, and from 7 to 12 ounces of silver, per ton of 2000 pounds.

Jan 1, 1897

By B. M. Harra, R. L. Hallows, O&apos

The term "modern automatic baghouses" as used in the title of this paper is intended to designate a general type of mechanical fume filter, introduced some 20 years ago and gradually improved since that time. It is characterized by its small filtering bags, enclosed in groups of 15 to 30 in steel compartments, and by its frequency of shaking, as compared to the old type of baghouse, which uses much larger bags, shaken at much longer intervals. Automatic baghouses are produced by a number of well-known manufacturers. Some recently constructed baghouses of the old type have embodied some of the principles of the automatic type, in that they are divided into several compartments, with separate fans for the different compartments, and flue headers arranged so that when the fan to any one compartment is shut down preparatory to shaking the bags in that compartment, the bags are put under suction by the draft from the other fans, thus making possible more efficient cleaning of the bags. These baghouses have motor-driven shaking mechanisms, and generally are operated under higher pressure and shaken at more frequent intervals than was the practice with the old style baghouse, and consequently have greater filtering capacity per unit of bag area. It is possible to interconnect the fan motors and the motors driving the bag-shaking mechanism, with suitable relays and timing devices, so that the operation of this type of baghouse also becomes to a considerable extent automatic. These baghouses are intermediate between the old style of baghouses, strictly speaking, and the completely automatic baghouses. They may he considered just as modern as the latter, and their proponents can no doubt cite many advantages for them. The authors are less familiar with them than with other types, and the following discussion will be limited to a comparison of the automatic baghouses and old style baghouses, with particular reference to the experience of The Eagle-Picher Lead Co. and The Eagle-Picher Mining and Smelting Company.

Jan 1, 1937

By L. P. Teas

The year 1931 has been one of unusual interest in Gulf Coast petroleum development, not so much because of the number of new prospects discovered, for apparently none of any present distinction have been found, but because of the discovery of so many new oil fields and the proving of so many old prospects. During the year 10 new oil fields have been found on the Coast; five in Louisiana and five in Texas. Two suspected salt domes were proven by the drill. Production dropped from a daily average of 192,000 to 162,670 bbl., or an average of 58 bbl. for each producing well, and active operations from 189 to 119. During 1931 the Coast produced approximately 48,600,000 bbl., or 44 per cent less than in 1930, when 86,500,000 bbl. were produced. The daily return at the beginning of the year was $192,000 and at the end only $126,780, the price having dropped from $1 for A grade and a range of $0.75 to $1.22 for B grade to a price range of 70 to 86c, or an average of 78c $ per barrel at the end of 1931. The average Coastal well produced 17,400 bbl. of oil during 1931. During the year development in the old fields has continued active at Barber's Hill only, although some work is in progress at Humble, Pierce Junction, Refugio and Pettus. Clear Lake is active but the large ownerships will prevent the "boom" type of field. Production is being held fairly steady at Barber's Hill and Pierce Junction, but has declined rapidly during the year at Refugio, Humble, and to a lesser degree at Pettus. The 6000-ft. production at Barber's Hill has shown a decided drop during the year and has not measured up to expectations.

Jan 1, 1932

By G. R. St. Pierre, L. M. Adelsberg, R. Speiser

The rate of scale fot'~I~ti0n on tantalum held in H20-Hz-Ar gns mixtures at temperatures between 840" and 1250°C is related to gas composition and ternpevature. It is found that water vapor partial pressure determines the oxidation rate at a given temperature and that the oxygen potential as fixed by the water vapor to hydrogen ratio Ins no significant effect on the oxidation rate. The Ta205 scale formed during oxidation is composed of an inner lattice-dijf~ision barrier and an outer layer of- cracked/porous oxide 1 HE oxidation of tantalum at temperatures less than 800°C is characterized by solution of oxygen into the metal,'-' the formation and growth of suboxides into the metal,')2~10-15 and the delayed nucleation of the highest oxide, Above 800°C, Ta205 is found to nucleate rapidly10, 11, 15, 16 except at low oxygen pressures:15 however, there is uncertainty regarding which does not retard the oxidation process. For each gas con~position and temperature investigated, the oxidatioz rate becomes constant after a short adjustment period. It is shozm that a constant oxidation rate nzay pre~?ail even though the tlzickness of the inner lattice-dijjitsion layer of Ta205 is clanging. TFze initial czcrz!ature of the typical 'Paralinear" oxidation curve may result froprz causes other than an increasing thickness of tlze inner protective layer. the detailed mechanisms of the high-temperature oxidation. Peterson, Fassell, and wadsworth17 observed linear oxidation behavior for tantalum in oxygen at temperatures between 600" and 1000°C. They reported that equilibrium adsorption of 0, occurs on a surface prior to the rate-deter mining step of the reaction. Cowgill and stringer1' confirmed the observations of Peterson and his coworkers. They stated that the rate-determining step of the reaction could be either the incorporation of adsorbed oxygen into the anion lattice or the dissociation of 0, at the gas-oxide interface. The relative rates of the two surface reactions were proposed to be dependent upon the reaction temperature and the oxygen pressure. stringerlo subsequently reported that the reaction surface is located somewhere

Jan 1, 1968

By Charles O. Thompson

In 1867 the city of Worcester walled in the Mill Brook for its main sewer. This stream, one of the important affluents of the Blackstone River, flows through the city in a southwestenly course from Salisbury Fond, and along its valley a considerable part of the heavy manufactories of the city are placed. At two points, a mile apart, a sufficient fall occurs to be turned to account for motive power, and at many points it was the right and practice of the riparian proprietors, prior to 1867, to use the water for steam and other manufacturing purposes. But the

Jan 1, 1881

By Ali Altway, M. E. Tunison, T. W. Chapman

Simulations of various contactor configurations for simultaneous extraction or stripping of two metals reveal the dependence of conversion and selectivity on operating and design parameters A two-film mass transfer model is used to provide the rates in countercurrent column and stirred-tank cascade calculations Even in these mass-transfer-limited cases the stoichiometry of the extraction reactions introduces nonlinearities and interactions between the two metal transfer rates, but these can be represented In a suitable model One conclusion is that a countercurrent column should be considerably more efficient than a cascade of mixer-settlers of comparable size.

Jan 1, 1981

By S. L. Crouch

The application of a simple, two-dimensional computer technique for evaluating rock burst potential in cut-and-fill stopes was investigated. The principal purpose of the study was to compare the effectiveness of high-modulus fill and destressing as aids in the control of rock bursts. Two conclusions that are probably of general applicability are drawn. First, high-modulus fill is ineffective as a means of increasing the mine stiffness and acts to control rock bursts only if it supports enough load to reduce substantially the stresses on the unmined vein material. Second, destressing is most effective if it is performed when the vein material is near the point of failure.

Jan 1, 1975

By James R. Cudworth, Joseph C. Mead

The Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manufacturing puzzolan cement; two companies, Birmingham Slag Co. and Woodstock Slag Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. NO Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive. Sources of Slag In the Birmingham district there are 22 blast furnaces, of which the majority are in blast. The present production is 165,000 tons of pig iron monthly; the production in 1935 was 1,297,960 gross tons1. There arc also two blast furnaces at Gadsden and one ferroalloy electric furnaee at Anniston. From these two sources is obtained slag to approximately 1.1 tons per ton of pig iron. History of Development of the Industry The history of the local utilization of slag as an industry probably starts with the Birmingharii Slag Cement Co. This company was

Jan 1, 1938

By Joseph C. Mead, James R. Cudworth

The Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manufacturing puzzolan cement; two companies, Birmingham Slag Co. and Woodstock Slag Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. NO Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive. Sources of Slag In the Birmingham district there are 22 blast furnaces, of which the majority are in blast. The present production is 165,000 tons of pig iron monthly; the production in 1935 was 1,297,960 gross tons1. There arc also two blast furnaces at Gadsden and one ferroalloy electric furnaee at Anniston. From these two sources is obtained slag to approximately 1.1 tons per ton of pig iron. History of Development of the Industry The history of the local utilization of slag as an industry probably starts with the Birmingharii Slag Cement Co. This company was

Jan 1, 1938

J. T. Pullon, Rowangarth, Roundhay, Leeds, England :— In discussing Mr. Lee's paper, I wish to call attention to the fact that Mr. B. II. Thwaite (who was heard here yesterday on the subject of the application of blast-furnace gas for the production of power, of which he was undoubtedly the pioneer) read, at the Engineering Congress in Glasgow in 1901, a paper on the profitable utilization of power from blast-furnace gases,' in which he suggested the diversion and cleaning of the whole of the waste gases coming from the blast-furnace and their utilization for power-production, so as to obtain, with proper manipulation, from 4 to 6 times the efficiency of present methods. He suggested also the heating of the stoves with producer-gas of a higher and therefore more suitable calorific value, so as to maintain them in a constant state of maximum efficiency, free from dust, and to avoid the irregular working of the furnace, besides obtaining a maximum supply of air-blast, of 15 or even 20 lb. pressure, by means of internal-conibustion blast-engines driven by the cleaned waste furnace-gases, with a surplus of gas left for other uses. Since that time, in view of the necessity of having a stand-by plant, immediately available, in case of strikes or other reasons causing the banking or blowing-out of the blast-furnace, he has developed, as an addition to his other types of producer, a high blast-pressure gas-generator, producing a gas identical with, or somewhat superior to, blast-furnace gas; and in which all the ash of the fuel is turned into fluid slag, which is available for, the production of slagwool. The gas is a little richer in carbon monoxide than average blast-furnace waste gas, and has only from 1 to 3 per cent. of hydrogen. Fig. I, drawn from a photograph, shows a plant containing this generator, now in operation at Leeds. It is made in units of from 1,000 to 10,000 h.p. capacity for each vessel, and coupled,

Jan 1, 1907

By Robert M. Doerr

A method, based on radial distribution analysis, was developed for determining the effect of size to which a given ore is broken on the potential recovery in beneficiations targeted to selected concentrate grades. A measuring microscope and computer analysis are used to obtain the radial distribution of the valuable component in polished sections of ore.

Jan 1, 1975

By W. O. Hotchkiss

AN ESSENTIAL mental equipment for planning exploration is the fullest possible. knowledge of the way in which the orebodies occur in the region to be explored, also the realization that in no mining district is this knowledge complete, and that new: facts of importance will he revealed to the explorer in every exploration if he is in the proper frame of mind to grasp them. The geology, of the ore deposits of the Gogebic Range for a long, time was thought to be relatively simple, but work in recent years, by several men, has proved that this is not the case. We now realize that we are far from knowing all the factors that have resulted in the localization of ore deposits. For example, we have long known that the intersections of the dikes and. the foot wall were favorable places to look for ore, but only within the last few years have we learned that there are several horizons' in the various members, well north of the foot wall, that are likely to carry ore. The influence of the numerous cross faults on orebodies is not known or appreciated beyond a general realization that they are important. Just how they may be favorable or unfavorable to the localization of ore is not known. Such elementary information as the positions of these faults is just beginning to appear on the mine maps. Such being the condition, one can hardly overestimate the importance to the various operators and fee owners of careful studies of conditions in their properties for the purpose of assuring themselves that they are not missing valuable ore-that they are doing all the exploration that their situation demands in order to secure maximum returns. Valuable ores have been missed in the past and will be missed in the future. Only with a complete knowledge of all the factors that have united to produce ore could anything else be expected. The purpose of this paper is to call attention to these facts briefly and to suggest a few of the principles that should guide effective exploration. The foremost principle is that the man who starts out with the idea that he knows all about the mine geology of the Gogebic Range is starting with a heavy handicap.

Jan 8, 1920

By John Norton

FOR many years the copper-bearing steels have been of considerable interest to the metallurgist because of their corrosion-resistant properties. More recently the discovery of their definite age-hardening characteristics has focused attention on them again. In a recent paper, Smith and Palmer(1)? have given an admirable description of the behavior of a considerable number of steels of this type and a study of their results suggests two questions, of a more or less fundamental sort. In the first place, it has been plainly shown that the hardening effect of added copper does not increase up to the maximum solubility of copper in iron as given by earlier investigators, but reaches its greatest value considerably below this point. This fact suggests that either the solubil-ity is not, so great as previous investigators have stated, or that the age-hardening mechanism is not the simple precipitation phenomenon that has been postulated. In the second place, the nature of the aging mechanism in this partic-ular system should be determined. Recent developments in the study of age-hardening processes have shown that the increase of hardness is often, but not always, accompanied by precipitation and the action of a particular system is not predictable on the basis of its components or type of phase diagram. It would be of considerable interest to study the aging of the iron-rich iron-copper alloys in detail. One would like to know whether the aging mechanism is different at high and low aging tempera-tures, and whether the extreme sluggishness of the system may perhaps represent some new type of aging process.

Jan 1, 1934

By A. J. Erickson, W. W. Atkinson

Concepts developed in a geologic data recording system at the Victoria, Nevada breccia pipe-skarn copper mine, are not fundamentally new, but represents expansion of earlier ideas. The basic philosophy is that a high quality geologic data base is necessary and should be complete, clear, standardized, neat, quantitative, and readily useable. It may be multi-colored or simply black and white. Graphic, descriptive and quantitative recording of data is essential. A format for core logging is presented and discussed, as well as a mu1tiple overlay system for recording data gathered in surface mapping.

Jan 1, 1984

By Frank C. Appleyard

The two calcium sulfate minerals-gypsum and anhydrite-occur in many parts of the world, and gypsum has long been of economic importance in the family of industrial minerals. Gypsum, the dihydrate form of calcium sulfate (CaS042H20) and anhydrite, the anhydrous form (CaSO4) are frequently found in close association, and it is seldom that a calcium sulfate deposit will consist exclusively of one mineral or the other. Although known gypsum deposits are extensive, anhydrite makes up the largest part of total calcium sulfate reserves. However, it has very minor economic use, and most of the following discussion will be devoted to gypsum. Calcium sulfate is one of the principal con- stituents of evaporite deposits, and when pure, has the following composition: [ ] Deposits of pure gypsum or of pure anhydrite which are large enough to be considered commercial have never been found because of both the metastable relationship between the two minerals, and the presence of impurities such as calcium or magnesium carbonates, chlorides, other sulfate minerals, clay minerals, or silica. As a result most mine production of gypsum will range between 85 and 95% pure. Often it is used as mined, although in certain cases, one or more forms of mineral beneficiation are employed to upgrade the product.

Jan 1, 1975