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Jan 1, 1935

Jan 1, 1935

Jan 1, 1935

Jan 1, 1935

Jan 1, 1935

By W. A. Vine

WHEN a hole is made in a stressed solid, such as rock pierced by mine openings, equilibrium of the solid is destroyed. To re-establish that equilibrium the stress condition in the rock surrounding the opening becomes rearranged. This rearrangement may or may not develop local stresses in the vicinity of the opening which exceed the elastic strength of the rock. Since stability of the opening depends, therefore, on the strength of the naturally occurring rock surrounding the opening, this rock is an engineering material of construction, and all rock affected by the associated opening or system of open- ings may be considered a structure. The term invert is chosen to describe the formation of the structure —built from the inside, as it were, and a consequence of mining rather than an entity built for a purpose. By definition, an invert structure is formed when openings are made underground and is composed of that material on the solid side of a rock-air interface wherein the stress condition is affected by the associated opening or system of openings. The shape of an invert structure is never clearly defined; the skin of the structure may be mapped, and even described, but the boundary of the structure within the solid rock mass must be arbitrarily set. The name geomechanics is proposed to describe a branch of scientific knowledge which will encompass principles and working hypotheses for behavior and design of invert structures. It is foreseen that study

Jan 1, 1956

By H. Hanemann

Discussion of the paper of H. HANEMANN and PAUL D. MERICA, presented at the New York meeting, February, 1916, and printed in Bulletin No. 108, December, 1915, pp. 2371 to 2385. JOHN A. MATHEWS, Syracuse, N. Y.-I should like to ask the authors if there is any evidence of chemical change resulting information of, alpha iron from the gamma crystals found in nickel steel of high nickel content when stressed beyond the elastic limit, similar to the effect produced by drastic cooling. Would the stresses mentioned and the drastic cooling both result in an increase in magnetic induction? I would also like to ask the authors if they have made a test of the hardness. It would be very interesting to see whether the hardness decreased under the conditions of stress, as might be the case if alpha iron were produced. PAUL D. MERICA, Washington, D. C.-While it is impossible to state absolutely, it is my belief that the effect of deformation is approximately the same as, that of -drastic cooling, but we did not make a test, of the hardness.

Jan 5, 1916

By Francis J. Dennis

Many factors govern the value of dredging-ground, and much capital can be wasted by the mistaken policy of contracting for the purchase of property arid the installation of machinery before a thorough examination has been made. To the uninitiated investor the presence of gold is generally the criterion, and very superficial evidence is necessary to satisfy him as to this point. he couuiclers the comprehensive report of a competent engineer as a wasteful extravagance, aild cannot understand why the engineer requires so much time and money to ascertain the information on which to base his conalusions, when the promoter can furnish him such pleaaing and satisfactory data with but little expenditure of time aud money. The uninitiated investor will often optimistically risk capital for purchase and equipment, and riot uiitil the veuture comes to grief does he learn that the condition8 are wholly unsuited for dredging. In many instances, a short preliminary examination by a competent engineer would have disclosed these facts. The mere presence of gold is by no means suficient; sonie of

Jan 1, 1912

By AIME AIME

ABOUT 55 attended the general session of the Nonferrous Metallurgy Committee on Wednesday afternoon. In opening the proceedings the Chairman, Frank G. Breyer, served notice of his intention to make an early start this year in securing papers for his committee. He voiced the thought that more importance should be attached to the prompt publication of data on new advances in practice; the record of technical progress should be written before the sharpness of the current image becomes blurred by the veil of time. As an illustration, Mr. Breyer declared that great strides have been made in the zinc industry during the past nine years, whereby zinc ore is converted directly to the oxide in large mechanical furnaces, yet the literature is confined to patents.

Jan 1, 1933

By H. V. Churchill

THERE are two distinct methods of combating corrosive conditions. The first and most popular method is to choose a surface or material which will give adequate service under the specific and general conditions which are present. The second is a control or modification. of the corrosive conditions to the end that metals and materials which would be attacked and corroded without such control or modification may be used. Under the first method of attack of the corrosion problem may be grouped such devices as the selection of metals or alloys which offer great resistance or the use of protective coatings such as paints, lacquers or metallic coatings. Such procedures are exceedingly useful. It is, undoubtedly true that most of the problems of corrosion will be solved by recourse to this first method of attack. However, it must be remembered that there are many conditions in which metals are used where the choice of the particular metal to be used must depend upon other factors than corrosion behavior. Some of the factors which may govern the selection of metals for specific use are the physical and mechanical properties of the metals. But there is another factor which is of prime importance and that is relative price. It is the pressure of these factors of mechanical properties, physical characteristics, and relative price that has acted as the stimulus for the second method of combating corrosion. The producer and user of various metals is confronted with the fact that because of mechanical properties, physical characteristics, or price, the use of a particular metal is desirable even though the corrosion conditions are adverse to the use of the metal. In many cases, the successful use of the metal may be made even though it is impossible to protect the metal by coatings. This is rendered possible by control or modification of the corrosive media.

Jan 1, 1929

IN describing the mining and treatment of ore at the Broken Hill Proprietary mine E. J. Horwood, superintendent of mines, gave the following account of the development of flotation there. It was in 1902 that the recovery of zinc from the ore by flotation was hit upon. The former general man-ager, Mr. Delprat, directed our then research officer, Mr. Carmichael, to try boiling the tailing with salt cake of which there was a considerable tonnage left over from the leaching process. The idea was the possibility of dissolving the zinc. Carmichael made the. Experi-ment, but, rather discouraged, took the glass beaker down to the general manager's office, remarking that he could not get the stuff to settle. On showing the beaker to Mr. Delprat, the latter recognized the marked distinction between the black scum on the surface and the rest of the tailings, and exclaimed: "Why, this is the very thing we are after; the zinc is floating!" Patents were applied for at once, but later on it was found that another investigator, Potter, had already hit upon the idea of flotation. His patents, however, were so involved with other operations that his process was impracticable. Litigation followed, but in the end the B. H. P. paid the Potter Company a substantial sum as settlement. In the case of Carmichael's beaker, the acid in the salt cake acted on the small amount of carbonate present in the ore, producing CO. bubbles. Owing to the aversion of sulfide crystals to being wetted, the gas as generated attached itself to the zinc in in-creasing quantities until there was sufficient to buoy the zinc particle to the surface. This action went The next problem was to apply the principle on a commercial scale, and this involved much experiment and developmental work. Various kinds of sloping copper pans with gas jets below to maintain the tem-perature were first tried, but were found too slow and too costly in operation.

Jan 6, 1928

By C. C. Bailey

Part I Problems of Mine Financing Directed primarily at the methods and problems of financing domestic mining ventures-projects involving one or more of the stages: exploration, development, commercial operation.

Jan 6, 1953

By N. A. Elmslie

This subject covers much ground, therefore it must be treated in a general way rather than in detail in this paper. Personnel To approach the measure of a mine, it is, of course, essential that the personnel be measured, and this measuring must be done in a circumspect manner and conclusions must be reached slowly. There may be one unit in the personnel of an organization that may be out of step with the remainder of the organization, not always because of lack of ability, but because of misplacement or lack of proper measurement of his capabilities. Too much time can scarcely be spent in the study or measure of the personnel ; in fact, a manager or a superintendent of a mine never completes his work along this line. Mine or Plant Just as no two men are alike, so no two mines or plants are alike; and yet there are many similarities. Find out what the similarities are, and this will help to make clear the dissimilarities. Try to visualize details of the difficulties, not because you will have to deal with them yourself, but to consider them in later studies of general problems. To outline all the steps to be taken in familiarizing oneself with a plant or operation would be impossible, but the following points may be of interest in any investigation. The study of a mine is generally made backwards-—that is to say, one sees the finished product first-—-but this is immaterial, because each step must be considered separately in any event. As a rule, there are certain heads under which the different features of mining can be placed, as follows: Ventilation.—Ventilation is usually the most important item in power cost and safety, especially in gassy mines. Quantity of air, water gage and power consumption, and finally analysis of the return air in full return and separate splits should be considered. Type of fan and type of power unit should enter into this study because it is important to view expenditures which are going on 24 hr. a day and 36.5 days in the

Jan 1, 1931

By C. V. Millikan, C. V. Sidwell

There is nothing more important in petroleum engineering than a definite knowledge of the pressure at the bottom of an oil well at any existing operating condition, and the relation of this pressure to the pressure within the producing formation. A knowledge of bottom-hole pressures is fundamental in determining the most efficient methods of recovery and the most efficient lifting procedure, yet there is less information about these pressures than about any other part of the general problem of producing oil. Determination of Bottom-hole Pressures Bottom-hole pressure may be calculated or determined by several methods. On an inactive well it may be calculated from the fluid head or, if the well is shut in, by adding the casinghead pressure, the static head of the gas and the fluid head. In wells flowing naturally through tubing the pressure at the bottom of the tubing may be calculated by adding the pressure at the casinghead between the tubing and the casing and the pressure due to the weight of the column of gas, but there is always possibility of error caused by fluid being in the annular space above the bottom of the tubing. If a well with tubing is flowing through either the annular space or the tubing, sufficient gas may be injected through the static space to insure that it is free of fluid but not sufficient to establish an appreciable friction loss. The pressure at the bottom of the tubing can then be calculated by adding to the pressure at the tubing head the pressure due to the weight of the column of gas. This is probably the most accurate method of calculating bottom-hole pressures. In wells flowing by gas-lift, the pressure at the point the gas enters the flow may be calculated by a gas-flow formula. Several types of pressure bombs have been used to measure the pressure at the bottom of wells. One is a piece of steel tubing with a check valve in the bottom and a connection for a pressure gage at the top. It is lowered into the well to the point at which the pressure is

Jan 1, 1931

By J. N. Houser

THE industrial relations between the Tennessee Copper Co. and its employees have developed a number of interesting things and have been most, profitable to the employees and to the company. It is noteworthy that considerable has been done without a formal organization of any kind built up through the efforts of the company. From time to time there have been discussions regarding the advisability of a formal organization and the decision has always been in favor of the present method. In the year 1919, the company was dealing with its employees through union committees and, after an understanding was reached, satisfactory results began to be obtained, but as time went on the committees did not function and it came to a question of how to reach the men. For the past two years, about once a month, but at no stated time, there has been a meeting with a committee of employees consisting of 40 or 50 men out of 700. This committee is secured by notify-ing the locals. In addition, the Service Department notifies a number of men not represented in the union, so as to have a large representative committee. The meetings are on company time and the men are rotated, so that in time every employee attends , at least one meeting. All department heads and a number of foremen also are present. The operating plans and policy of the company are set out at the meetings and the market outlook for products is discussed. Explana-tions are also given of anything that has come up since the last meeting which affects the employees, and an effort is made to inform them of what will probably happen in the next month or two. Once a week there is a meeting of department heads with the manager, for discussion of all operations as a whole and such depart-mental details as seem advisable. When the depression started, it was necessary to curtail operations and the reasons were carefully explained; before the men were laid off, the employees as a whole were advised of the coming layoffs through these meetings. They were also advised generally who would be retained and given an opportunity to express their agreement or their. disapproval. In fact, an effort was and is being made to keep the employees advised in advance of matters affecting them and to give them full opportunity to express themselves.

Jan 12, 1922

By Haydn H. Murray

Although alumina constitutes about 15% of the earth's crust, it is expensive to separate and purify for the production of aluminum with the exception of the alumina in bauxite. The United States has a variety of nonbazurite resources that could substitute for bauxite, including high alumina clays, alunite, dawsonite in oil shale, anorthosite, and nepheline venite. Each of these resources is discussed from the standpoint of geology, geography, processing, and potential recovery. Potential byproducts include alica from clays, potash and sulfuric acid from alunite, soda ash from dawsonite, and soda ash and potash from anorthosite and nepheline syenite.

Jan 1, 1983

New Products Equipment

Jan 6, 1950

By Thomas Read

SUMMARY THE cost of labor turnover in industry is so large as to justify the adoption of almost any means to bring about its reduction. Intensive study has shown that faulty methods of hiring and discharging men is the most important factor in labor turnover. Complete control over hiring and discharging by the foreman is a relic of outgrown industrial conditions; centralized hiring permits this work to be put on a scientific basis and also does away with many serious evils that cannot otherwise be reached. Centralized hiring does not impair the authority of the foreman; he hires his men from the employment office and discharges them back to it, instead of from and to the street. The employment manager, being a direct representative of the employer, tends to restore the former relation of direct intercourse between employee and employer that was helpful in avoiding friction between them. Being a specialist, he is able to bring special knowledge and skill to bear upon the task of selling employment in his concern to desirable workmen; lie is also able to give the foreign workman the special attention he requires. Employment managers have been used for the past few years by a number of large organizations, a few of which are engaged in the mining and metallurgical industries. They have invariably reduced labor turnover, in some cases to as little as one-tenth of what it had been. So great a reduction is due in part to other changes made in the light of the data made available by scientific study of the labor problem. In my former paper on personnel work1 I advocated the more general use of the employment manager in mining and metallurgical enterprises as a means of reducing labor turnover. The form of organization recommended seems not be to understood by all, and I have requested the privilege of explaining it at greater length, since it is perhaps the most important factor of all in personnel work, and has a vital influence on the cost sheet of every industrial enterprise.

Jan 2, 1918

Jan 1, 1942

C. H. GIBBS,* Salt Lake City, Utah (written discussion?).-The development of the coke industry in Utah had a somewhat checkered career for the first 50 years of its existence. About 1851 the iron-ore deposits of the Iron Springs and Iron Mountain mining districts, Iron County, Utah, were discovered. Obtaining of iron for any purpose at the time involved its shipment from the Mississippi River to Utah, by ox-team. The result was that the pioneers endeavored to establish an iron-ore smelting plant at what was known as Iron City, near Iron Mountain, in Iron County. Bishop Taylor, who headed this enterprise, endeavored to obtain coal suitable for coking from the Cretaceous coal measures immediately east of Cedar City. A few small bee-hive coke ovens were built and lump coal was coked in these ovens; or, more properly speaking, the volatile matter of the lump coal was driven off, leaving a carbonized material that retained the lump shape, although it was extremely, friable. This coke was promptly found to be unsuitable for iron smelting, not only clue to its extreme weakness under smelting load, but also because of the fact that it carried about 5 per cent. sulfur. Bishop Taylor made a very thorough and exhaustive effort, covering a considerable period of years, to locate suitable coking coal in Southwestern Utah. His efforts failed, and in 1902 the iron-ore property acquired by him and associates was sold to the Colorado Fuel and Iron Co. It is of interest to note in this connection that the iron-ore deposits of Iron County at present are the largest known undeveloped iron-ore fields on the North American continent. It is safe to say that there is at least one hundred million tons of 55-per cent. ore actually in sight. In 1878, coal-mining operations were begun at Connellsville, in Huntington Canyon, Emery County. Ten 8-ft. bee-hive ovens-were constructed, and lump coal was carbonized for use in the Salt Lake valley smelters. The product was somewhat better than that obtained in Iron County, but was still of very inferior quality. It had to be hauled a distance of 140 miles by wagon to the two small smelters then operating in Salt Lake valley. These ovens operated only a very short time. The next move toward obtaining a coking coal was in 1889 when the Pleasant Valley Coal Co. began operations in the Castle Gate district. In 1890, eighty 8-ft. bee-hive ovens were constructed, and the product. was used until 1900 in all the smelters in Utah. During this period, 124 additional. ovens were constructed, making a total of 204 bee-hive ovens operating at Castle Gate.

Jan 11, 1918