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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 Inter-national 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 avail-able 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 clone to best advantage.

Jan 1, 1938

By Lombard Squires, W. K. Lewis, W. I. Thompson

Clays consist predominantly of hydrated silicates of alumina. The formula is frequently assumed to be A1203 . 2Si02 . 2H20,'and certain of I. North Carolina. Low plasticity. 11. Same as I, after washing. Low plasticity. III. Tennessee. Good plasticity. IV. Pennsylvania flint fireclay. Low plasticity. V. Laredo, Texas. Very plastic. CaO/Na2O corrected for GO2. VI. San Antonio, Texas. Fine grained, highly plastic. Moisture and CO2 were determined together at 18.8 per cent. VII. Selected crude bentonite, California. " Data from R. Ries: Clays. John Wiley & Sons, New York, 1927. them undoubtedly have substantially this composition, but in general the ratio of silica to alumina is considerably higher. However, they always contain water of chemical constitution, as shown by Table 1.

Jan 1, 1935

GENERAL GEOLOGIC DESCRIPTION The Escalante silver deposit located in southwestern Utah is an epithermal vein system consisting of a hanging wall and footwall vein, straight along strike and dipping about 1.2 rad (70°). The veins consist of banded quartz and calcite fissure fillings between volcanic wall rock that are silicified for some distance outward from the vein. The walls of the veins are sharp and the silver values are irratically distributed through the various bands within the vein. Only very low grade values are to be found in the wall rock on either side. The portion of the veins above the water table have been somewhat leached, with some secondary enrichment below. The mineralogical zonation is variable due to a fluctuating water table through geologic time. SAMPLE MANAGEMENT AND COMPOSITE ASSAYS Sample data for the deposit was obtained from over 50 diamond drill holes, from channel samples cut at intervals across a drift, and from scattered surface trenches along the out- crop of the hanging wall vein. Fig. 13-1 is a surface plan map showing the vein outcrop and some diamond drill locations. Two cross sections through the vein are shown in Figs. 1 3-2 and 13-3. Nearly all of the diamond drill core of vein material was assayed in 0.3-m (I-ft) lengths, from which weighted composite assays were manually calculated for the horizontal thickness of the vein. The centers of the composited samples were plotted in north and east coordinates and by elevation, and locations and assay

Jan 1, 1980

By A. B. Parsons

PUBLICATION of this little volume is a luxury that the Institute itself could scarcely afford. In truth, no engineer nor geologist, no assayer nor metallurgist would be likely to enhance his knowledge, improve his technique, or cut his own operating costs by reading this excellent translation of two booklets first published circa A.D. 1520. It is doubtful if the present enterprise would, in a practical or tangible way, "promote the arts and sciences connected with the economic production of the useful minerals and metals." And such, is the prescribed purpose for which the funds of the Institute should be spent. Fortunately for the Institute, the Seeley W. Mudd Memorial Fund is not so circumscribed; and the Fund Committee enjoys, greater liberty of action. The sponsorship by the Mudd Fund in 1942 of the publication of The Pirotechnia of Vannoccio Biringuccio, as translated by Dr. Smith and Mrs. Gnudi, was an innovation-indeed something of an experiment. Not only was the content of the volume significant mainly for its "cultural" and "scholarly" attributes; -but the format, an outstanding example of the fascinating art of bookmaking, bore no resemblance to the ordinary technical book. The Committee, frankly, was surprised at the enthusiastic reception accorded the volume. When a second edition was required, the Committee became convinced that the publication of material of this type, particularly if printed and bound in attractive form, was an appropriate avenue for utilizing a moderate proportion of the monies available from the Fund. The Bergbüchlein and the Probierbüchlein antedate by some years the first publication of De la Pirotechnia and of De re Metallica; but Georgius Agricola, the author of the latter work, made good use of the material in the earlier volumes. As pointed out in the Introduction, both

Jan 1, 1949

Arthur H. Elliott, New York, N. Y.: We have all been very much interested in the results of Dr. Bone's work, which Mr. Ellis has presented to us this evening. The high temperatures attained by this method perhaps afford us an explanation of the temperatures reached in the puddling-furnace with its crude and almost primitive methods of burning fuel, by means of which we have, nevertheless, been able to melt iron in a comparatively short time, and keep it in a molten condition down to a high degree of purity. No doubt many of us have wondered, as I have done, how such a result could be obtained in such a way; and it occurs to me that, perhaps, Dr. Bone has supplied the explanation in disclosing the effect on combustion of burning gas and air after passing through, and in contact with, a porous refractory body. May not the fettling of the puddling-furnace have, in some degree, an effect upon the combustion like the influence of the porous diaphragm employed by Dr. Bone ?

Jan 1, 1913

Under date of Sept. 30, the following open letter was addressed to the Members of the Colorado Section of the American Institute of Min-ing and Metallurgical Engineers by a Colorado Committee: At a meeting of the Colorado Section of the American Institute of Mining and Metallurgical Engineers, held on Friday, Sept. 19, a reso-lution was unanimously passed condemning the Engineers' Licensing Bill passed at the last session of the State Legislature, and requesting the Chairman to appoint a Committee to act in conjunction with the other National Engineering Societies and the Colorado Metal Mining Associa-tion, with a view to securing its repeal at the extra session of the Legis-lature which the Governor has expressed his intention of calling. It may be within your knowledge that the bill in question was passed by the Legislature and signed by the Governor without the knowledge of any of the National Societies, and of few if any of their members. Under its provisions residents of other states cannot even come into this to examine a mine without securing a license, and aliens (among whom are many honored members of, the profession in Colorado) cannot obtain such a license at all. The mining industry in this state needs the coopera-tion of outside engineers, and we should welcome any assistance from them that will tend to develop our resources. To attempt to discourage the activity of visiting engineers will inevitably react on us, and brand the state as being hostile to brains and capital from outside. The difficulty of securing a license will prove a serious handicap to young engineers starting out in the independent practice of their profession. Moreover, a license issued to au engineer qualified in one branch will entitle him to practice in any other: so that the license is apt to mislead the public.

Jan 11, 1919

By C. L. Dake

Many proposals have recently been made regarding the broadening of engineering education, often with little consideration of the problems their application involves. The chief purpose of this paper is to point out how many and how complex are the questions that absolutely must be answered, in any conscientious effort to solve the problem of liberalizing engineering curricula. Among proposed additions, more training than is now given has been urged in public speaking, report writing, business law and contra s, general finance, money and banking, scientific management, gene ' economics, economic and financial history, social problems, labor pre lems, public ownership, psychology and similar related subjects. T urge in this direction is widespread and persistent. In discussing the blem, the following questions must be given careful consideration, an he absolutely definite conclusion reached: 1. The Present Curriculum Load.—Is this load actually too heavy? In the face of this load, is there room to add broadening subjects to our curricula? Can elimination of present subject matter make room for such additions? Can an elective system accomplish the desired end? 2. Problem of Early Specialization.—Is early specialization a weak ness? Is industry forcing early specialization? Do our varied degrees demand early specialization? Can broadening be harmonized with the present degree of specialization? 3. Graduate Work to Solve the Broadening Problem.—Can we add the desired work in the graduate school? Are the proposed additions of graduate caliber? Is it desired to reduce graduate standards? Can present undergraduate work be removed to the graduate school, to make room for desired broadening courses? Is graduate work normally broadening, or is it specialization ? 4. Importance of Proposed Additions.—Will they increase entrance salaries? Will they increase the engineer's efficiency? Will they raise

Jan 1, 1934

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

By W. P. Blake

One of the most remarkable iron-ore districts of the world is found in Southern Utah, in Iron County, about 270 miles south of Salt Lake City, and 10 miles west of Cedar City. This region has long been known in a general way; but, being at present somewhat difficult of access, it has been rarely visited by 'any of our members. Professor Newberry has published somewhere a short description. Last year, by the invitation of J. R. Walker, Esq., of Salt Lake City, one of our associate members, I formed one of a party, including Professor G. W. Maynard and W. S. Keyes, to visit and inspect the region. A special car was placed at our disposal by the courtesy of Hon. John Sharp, Superintendent of the Utah Central Railway. From the present southern terminus of the road at Milford, a drive of 55 miles took us to Cedar City, about 10 miles east of the iron region. The ores outcrop in a low range of hills or mountains, and stand out in such bold relief from the general surface, and are so massive and jet black, that they may be seen for miles before they are reached. These outcrops extend in long lines over the hills, and mark very . clearly the course of the beds, conforming generally to the inclosing stratified formations, probably of Palaeozoic age. These rocks are somewhat obscure, but there are large outcrops of limestone without much alteration. This, in places, appears to be the adjoining rock, at others the wall-rocks are porphyry, and at others apparently a quartzite and a fine-grained felsite. The beds of iron-ore are from 10 to 100 feet and more in thick ness, and some of the outcrops extend unbroken continuously for 1000 feet and more. It consists chiefly of magnetite and hematite,

Jan 1, 1886

By S. A. Shoop, J. J. K. Daemen

Site-specific blast vibration prediction can be more accurate than using a universal prediction equation. Vibrations from 37 blasts were monitored using three seismographs. Data analysis showed that square root, cube root, and site-specific scaling predicted ground motion with equal reliability. Imprecise prediction is caused by geologic and blast variability, particularly, inaccurate delay times. Vibrations at some mines were consistently lower or higher than vibrations predicted from US Bureau of Mines (USBM) equations. Vibration restrictions based on USBM studies could then be too conservative or too lenient. Predominant vibration frequencies were generally less than 50 Hz, but several blasts had significant energy up to 125 Hz. In some cases, energy was concentrated at frequencies corresponding to delay intervals.

Jan 1, 1985

Copper from Central Africa was well known to the Arab slave traders who depredated the country in the nineteenth century. By the 1870's slave raiding was so intense that the habits of the tribes were disrupted, and they no longer worked the copper deposits or made the crosses and bars of copper which had been their custom. In fact, the country had been greatly depopulated by the slave raiders. News of this horror was spread to the civilized world by missionaries and, in particular, by David Livingstone's writings. Whether to extend geographic knowledge, to suppress slavery or for national aggrandizement, the rush for African territory was on at the end of the nineteenth century. Cecil Rhodes at this time was established by his successes in diamonds and gold. He obtained the blessing of Lord Salisbury in 1889 to form the British South Africa Company under crown charter. His objectives were to occupy the lands north of the Zambezi for England and pay for development out of the country's mineral deposits. He planned to occupy the territory and close the gap to form an all-British route from the Cape to Cairo, one of his great dreams. With this master plan in mind he sent his agents into the field to make treaties with the tribes.

Jan 12, 1962

By Robert F. Griffith

In 1948 when the U.S. Bureau of Mines began the investigation of domestic monazite placers for the Atomic Energy Commission, deposits of this type amenable to large-scale operations were unknown in the U. S. Intensive search for such deposits had not been carried out in the past. Problems to be met included scarcity of men with placer experience and need for development of new exploration, evaluation, and analytical procedures. As a result of the exploration program three dredges have gone into operation in one area in Idaho and another dredge is operating in South Carolina. Search for Deposits In the search for areas to be investigated for monazite, the first step was a thorough study of all available literature reporting occurrences of the mineral. Initial work was guided largely by many reconnaissance reports prepared by the U. S. Geo- logical Survey and the AEC. As the work progressed many new deposits, not mentioned in the literature, were called to the attention of USBM engineers by prospectors who had noted the presence of the yellow, heavy sand while prospecting for placer gold. Every prospector was given an attentive ear.

Oct 1, 1955

The Section on Aerial Geologizing of the American Institute of Mining and Metallurgical Engineers convened on Monday afternoon, Feb. 17, 1936, during the Annual Meeting of the Institute. Mr. Theodore Marvin presided. Chairman Marvin.—We hope to get through with the papers on the program in time so that you can examine the instruments that are displayed here, and also the photographs and air views brought by the Fairchild people. This is what we might call the first bread and butter session of the Aviation Committee. The group, as many of you know, was started at the request of the Board of Directors two years ago. We have had two sessions since then, both of them of a somewhat general nature, their purpose being to point out the reasons why mining and petroleum engineers should be more interested in the facilities of aviation. Today we have two papers. The first is one by Mr. Eliel, of the Fairchild Company's California branch. In Mr. Eliel's absence, Mr. Gale, of the Fairchild Company, will read it. C. H. Gale.—Before I begin to read Mr. Eliel's paper, I would like to point out two instruments that he mentions- One is what he calls the solar-navigator, a new type of aerial navigating device which he has developed for use in flying cameras in aerial surveys. Flying a camera at high altitudes over unfamiliar territory is a very difficult procedure and only a few pilots in this country can do it. So far as I know, this is the first time this device has been discussed in public. Another facility I want to refer to in advance is the use of the stereoplanigraph in making contour maps from photographs. This is an extremely interesting procedure, which we are appreciating more than ever at the present time.

Jan 1, 1937

By R. F. Shurtz

This note calls attention to a contradiction in current eatistical theory and to corresponding difficulties in practice. These are significant concern in evaluating almost all ore deposits. The theoretical contradiction is that the commonly used spherical model for the semivariogram is not consistent with the usual definition of a "regionalized variable" as a mathematical function, the direct study of which "is excluded because its spatial variability is usually extremely erratic, with all kinds of discontinuities. . ." (Journel and Huijbregts, 1978). Specifically, this means a grade function that is too "rough" for interpolation to be useful. The practical difficulty is that the spherical semivariogram interprets the data upon which it is based in a manner that is, more often than not, demonstrably inconsistent with reality. This is attributable to the widely disregarded interaction between the sample pattern and the grade function. Each sample pattern "blurs" the grade function in its own particular way. It is as though the grade structure of the deposit were seen through a lens of poor resolution or reflected in a warped mirror, such as those found in amusement parks. The fitted spherical model embeds this sometimes dangerously blurred and distorted image in the Krige regression. A full analysis of these inconsistencies is to be presented later but, in the meantime, it seems urgent to communicate their effects so that those engaged in estimating ore reserves may be on guard. The spherical semivariogram has a sill and can be replaced by the corresponding covariogram. The equation of the spherical covariogram in normalized form, that is, variance and range both equal to one, is represented as: [ ]

Jan 1, 1984

The Library of the above-named Societies is open from 9, A.M. to 10 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special, attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that, the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library y forwarding copies of mining reports, maps privately issued, and similar material, which will be classified; indexed, and made availableto other members. Suggestions for additions to the Library, either y purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 8, 1914

CHARLES CATLETT, Staunton, Va. (communication to the Secretary*). -I hesitate to discuss in general terms a paper such as Mr. Wysor's, which bears evidence of so much careful and detailed investigation, yet it is the broad possibilities which his paper presents that are really attractive and his cautious conservatism may make us unappreciative of these possibilities. Mr. Wysor calls attention to the fact that the iron-ore mixture which he uses, carrying 0.28 per cent. of potash, is probably above the average. No doubt this is true, but on the other hand it may be very much less than the mixture at some blast furnaces or very much less than would be the case with special mixtures bearing the question of potash in mind. Unfortunately, iron ores are not ordinarily examined for potash, and with the ordinary analyst there is opportunity for very considerable error in the determination. The 10th Census gives 270 complete analyses of iron ore, on the accuracy of which we may rely. Of these, there are 21, or 8 per cent., that carry more potash than Mr. Wysor's mixture; 14 of these carry approximately twice as much, or more; eight carry approximately three times as much, or more; three carry approximately five times as much; one carries over seven times as much. It may be worth while to take some of the ores that are known to be high in potash and consider the possibilities in the light of Mr. Wysor's investigations.

Jan 5, 1917

Just three years after researchers announced its development, Dravo is putting the finishing touches on a new $60-million Thiosorhic lime mine/kiln complex near Maysville, Ky. Electric utilities in western Pennsylvania and Ohio have already signed long-term contracts for over three-quarters of the projected 907 000-t/v (1-million-stpy) production. Thiosorbic lime, a flue gas desulfurizing agent, proved in industrial testing that at high emission levels (greater than 3000ppm SO2) it could be twice as effective in SO2 capture as conventional lime, while eliminating the major problem of scaling and plugging of scrubber equipment.

Jan 4, 1977

By John W. Pack

At present the manufacture of metallic zinc, or spelter, in Missouri, is carried on only at the establishments located at Carondelet, or South St. Louis. Although the development of the industry has not yet reached that fulness which it has attained elsewhere in the United States, still the commanding advantages of position of these establishments are so evident that the prospective importance and magnitude of spelter manufacture in this State, and especially at this locality, can hardly be doubted. A study of the chemical and technical aspects of the business of these points cannot be without interest to the metallurgist as well as to the capitalist. I have endeavored to investigate, as far as was practicable, within the limits of a paper of this character, some of the problems connected with this industry, at the same time making a few comparisons of the results attained at some of the Carondelet works with those of other establishments with regard to which information could be obtained. In the prosecution of these studies I have been kindly aided by the managers of Carondelet establishments, and by Prof. Charles P. Williams, Director of Rolla School of Mines. To the latter I am especially indebted for assistance in regard to methods of analysis. To all these gentlemen I return my thanks for their valuable aid. Other sources of information will be duly credited in their proper places.

By Lawrence Addicks

Discussion of the paper of LAWRENCE ADDICKS, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 104, August, 1915, pp. 1471 to 1484. L. D. RICKETTS, New York, N. Y.--In the Southwest we have stored up millions of tons of tailings in which the copper exists partly as sulphide and partly in an oxidized condition. Mr. Addicks' first paper suggests a, likely process for the treatment of such material. His second paper 1 deals with the recovery of copper from clear solutions of notable strength, and such solutions may come from the sulphating roast or direct from the leaching of completely oxidized copper ores of which vast deposits are known to exist. What strikes me particularly about the latter paper is the keen perception shown and the clear manner in which the writer has attacked the fundamental principles of the process. He calls your attention to the fact that ferrous sulphate is necessary in the electrolyte and is an ideal depolarizer; that sulphurous acid must be, used to reduce the ferric sulphate produced and thus prevent re-solution of copper at the cathode; that mechanical agitation in the cell, in order to bring the ferrous sulphate in contact with the anode and the copper in contact with the cathode, is essential to efficient work; that lead anodes are

Jan 12, 1915

By U. Oko

The cause and the effect of disposing of tailings water from sulfide ore milling operation were examined. Dissolved metallic ions as well as dissolved sulfur-oxygen compounds (polythionates) can prove injurious to life in water streams. Polythionates originate in alkaline flotation circuits and may cause a severe drop in the pH of stream waters. It is proposed that a suitable "aging" period be allotted to tailings water to ensure complete conversion of polythionates to sulfate prior to neutralization and clarification treatment. Discharging alkaline solid-free tailings water without aging will cause downstream acidification. Artificial oxidation of tailings water can be economical only if the concentration of thiosulfate in solution is low. When the concentration is high, it is possible to reduce the concentration greatly by first acidifying the solution, because at a pH below 4 thiosulfate in water reacts to produce a precipitate of elemental sulfur and higher order polythionates. The residual polythionates can then be oxidized at great savings by natural aging or by chemicals such as ozone, chlorine, or peroxide. Chlorine may be an economical reagent for converting polythionates to sulfuric acid but the residual organo-chlorinated compounds can prove to be toxic to aquatic life. Ozone and hydrogen peroxide which do not leave a residue are preferred oxidizers.

Jan 1, 1976