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By Raymond Mancha

A test of any fan requires the determination of such data as fan pressure, air volume handled by the fan, and power input to the fen shaft. When testing operating mine fans of the centrifugal type, test methods have been employed, for the sake of convenience, that permit great latitude in detail of procedure resulting in wide variance in results by different investigators. Some controversial aspects of field fan testing are the result of past failure to define clearly the various forms of fan pressure and to a lack of understanding of the accurate procedure for the measurement thereof. Also, the anemometer for air-volume measurement, although convenient, if carelessly used and maintained is subject to a wide error range with variation in method of application and in instrument accuracy. The appearance of the axial-flow type of mine fan offers the possibility of refinements in field testing that were impractical with the centrifugal fan. First of all, the fan inlet and outlet are more sharply defined, giving closer agreement as to just where the fan begins and ends; thus there is less disagreement as to the proper location for measurements of fan pressure. The area of passage into the inlet of an axial-flow mine fan usually constricts, causing high air velocities with accompanying steadiness of flow. Thus the fan inlet offers an ideal location for accurate air-volume measurements with the pitot tube, the proper use of which is well established by code. Thereby the controversial aspects of such measurements are eliminated. Use of the Pitot tube also facilitates a more accurate measure of fan pressure, since the individual pressures measured can be properly weighted, as will be explained later. Determination of power input to the axial-flow mine fan operating in the field is subject to the same inaccuracies as with the centrifugal fan if the axial-flow fan is also belt driven. However, because of the higher rates of rotation usual with axial-flow fans, direct-driven units are more numerous and it is unnecessary to assume a drive efficiency, thus eliminating one possible source of error. It is the purpose of this paper to define and explain the various types of pressure measurements involved in a field test of an axial-flow mine fan, and to further explain the proper use of the Pitot tube when measuring pressures and volumes. DefinitioN of Fan Pressures The two fan pressures most commonly discussed are fan total and fan static pressure, each of which has the same meaning regardless of whether the fan is blowing, exhausting, or blowing and exhausting, as in the case of a fan with ducts connected to both outlet and inlet. Fan total presscre is the amount by which the total pressure of the air delivered by the fan exceeds the total pressure of the air received by the fan. This pressure is a measure of the maximum amount of the work done on the air by the fan that is available for external use.

Jan 1, 1942

By Raymond Mancha

A test of any fan requires the determination of such data as fan pressure, air volume handled by the fan, and power input to the fen shaft. When testing operating mine fans of the centrifugal type, test methods have been employed, for the sake of convenience, that permit great latitude in detail of procedure resulting in wide variance in results by different investigators. Some controversial aspects of field fan testing are the result of past failure to define clearly the various forms of fan pressure and to a lack of understanding of the accurate procedure for the measurement thereof. Also, the anemometer for air-volume measurement, although convenient, if carelessly used and maintained is subject to a wide error range with variation in method of application and in instrument accuracy. The appearance of the axial-flow type of mine fan offers the possibility of refinements in field testing that were impractical with the centrifugal fan. First of all, the fan inlet and outlet are more sharply defined, giving closer agreement as to just where the fan begins and ends; thus there is less disagreement as to the proper location for measurements of fan pressure. The area of passage into the inlet of an axial-flow mine fan usually constricts, causing high air velocities with accompanying steadiness of flow. Thus the fan inlet offers an ideal location for accurate air-volume measurements with the pitot tube, the proper use of which is well established by code. Thereby the controversial aspects of such measurements are eliminated. Use of the Pitot tube also facilitates a more accurate measure of fan pressure, since the individual pressures measured can be properly weighted, as will be explained later. Determination of power input to the axial-flow mine fan operating in the field is subject to the same inaccuracies as with the centrifugal fan if the axial-flow fan is also belt driven. However, because of the higher rates of rotation usual with axial-flow fans, direct-driven units are more numerous and it is unnecessary to assume a drive efficiency, thus eliminating one possible source of error. It is the purpose of this paper to define and explain the various types of pressure measurements involved in a field test of an axial-flow mine fan, and to further explain the proper use of the Pitot tube when measuring pressures and volumes. DefinitioN of Fan Pressures The two fan pressures most commonly discussed are fan total and fan static pressure, each of which has the same meaning regardless of whether the fan is blowing, exhausting, or blowing and exhausting, as in the case of a fan with ducts connected to both outlet and inlet. Fan total presscre is the amount by which the total pressure of the air delivered by the fan exceeds the total pressure of the air received by the fan. This pressure is a measure of the maximum amount of the work done on the air by the fan that is available for external use.

Jan 1, 1942

By -1ng. B. Stampa

Introduction The author investigates the technology available for mine flow reversibility by reversing the operation of the main fans. Air bypassing, reversed sense of impeller rotation, and blade angle overturning are indentified as the most important means of achieving the flow reversibility. The axial flow fan is studied in some detail and the important variables of fan capacity, pressure, and efficiency are compared. Although some references to rotor velocity vectors are made (Fig. 1) the subject is not presented in detail in order to stay within the paper's intent. Background Where applicable, the requirements of mine air reversibility are an important part of the overall mining operation and should be given proper attention during mine ventilation design. The need for preventing mine fires in intake shafts is the reason that, for a long time, it has been a requirement in the Eastern European countries to have the feature of flow reversibility built into all main mine ventilators. In West German coal mines, this requirement does not apply since higher priority is given to safety precautions. Some metal and mineral mines in the United States are required to have ventilation currents readily reversible in order to fight underground fires as stipulated by the Title 30, Mineral Resources, and by the mining laws of some states. From an equipment performance standpoint, assuming the validity of other flow technical data, the question of the ventilator flow reversibility is of ten related to the actual scenario of the begining of an emergency. Most of the time, the system operates within half of the design capacity only and assuming that the equivalent mine orifice is stable only a quarter of the design pressure must be produced by the fan in any event. For such an operating point, the effective gradient and energy losses can be disregarded since fire emergencies usually last for only a short period of time. Equipment Comparison Fig. 2 depicts a ventilation arrangement wherein the flow can be reversed through changing the functional position of the dampers (slideplate or blade type). Both axial or radial fans can be applied in this case. For the mine exhaust operation, slide plates (guillotines) I and I11 are opened while plates I1 and IV are closed. The flow thus encounters two reroutings, which due to the reverse ventilation flow cannot be equipped with proper sheet metal deflectors, and therefore large pressure losses result during the air reroute operation. When the intake operation is considered, the dampers I and I11 are closed and the pair I1 and IV is opened. For this arrangement, almost the same flow conditions exist as for the foregoing exhaust mode; however, one additional corner must be applied. Even if a highly efficient ventilator is used in one of the previously described systems, the additional pressure losses resulting from air rerouting plus those encountered between the planes "0" and "00" significantly affect the overall energy requirements. Illustrated in Table 1 are the relative component losses of even flows for evaluation of various detour arrangements. From the aerodynamics standpoint, when these components are being designed, serious consideration must be given to the individual levels of the pressure loss coefficient, 5. Should there be an increase in the sum of the loss coefficients due to the particular component selection such that, for example, the net change is 1.2; the resulting pressure to be produced by the fan can be calculated from:

Jan 1, 1981

By C. E. Brukl, E. Rudy, St. Windisch

The ternary-alloy system Nb-Mo-C was investigated by means of X-ray, melting point, DTA, and metallo-graphic techniques; a complete phase diagram for temperatures above 1500°C was established. Above 1960°C, niobium monocarbide and the cubic (Bl) high-tenzperature phase in the Mo-C system form an uninterrupted series of solid solutions. The ternary range of the pseudocubic q MoCl-, is very restricted. Dimolyb-denum carbide dissolves up to 44 mol pct Nb2C (2240°C), whereas the maximum solid solubility of MO2C in Nb2C does not exceed 5 mol pct. The order-disorder transformation temperatures in Mo2C and Nb2C are lowered by the mutual metal exchanges. Six invariant (p = const) reactzons occur in the ternary system; three correspond to class 11-type four-phase reactions involving a liquid phase, one to a class I (eutectoid)-type, and two further isotherms are associated with limiting tie lines. The results of the Phase diagram investigation are discussed, and the thermodynamic interpretation identifies the low relative stability of the binary sub-carbides in conjunction with the large stability diflerences between niobium and molybdenum carbides as the cause for the formation of a stable equilibrium between the monocarbide and the metal phase in the ternary reson. Due to their refractoriness, the carbides of the high-melting transition metals have received increased interest in recent years as base materials in composite structures for aerospace applications at high temperatures and for the development of self-bonded cutting tool materials; other novel fields of application include power reactors, where operation at high temperatures becomes essential for attaining high power efficiencies. In these applications, the increased reaction rates at high temperatures require a close consideration of the chemical interactions between the alloy constituents. As a consequence, a detailed knowledge of the phase relationships in the alloy systems is required in order to provide a sound basis for developmental -type work. Partly as a result of the considerable experimental difficulties associated with the investigation of this high-melting alloy class, no complete studies of ternary metal-carbon systems have been performed until recently. Even the high-temperature phase relationships in the binary transition metal-carbon systems have been delineated only during the past few years to a degree of accuracy required for a more detailed study of ternary or higher-order alloys. In recent investigations of binary and ternary systems of refractory transition metals with carbon, boron, and silicon,&apos; alloys from the ternary systems Nb-Mo-C became of interest because of the demonstrated possibility2,3 of obtaining compatible composites based on metal + monocarbide combinations. In the meantime, however, studies in other, but related, ternary metal-carbon systems, such as Ta-W-C, have shown that the solid-state equilibria may change significantly toward higher temperatures (>2000°C), and that extrapolations based on low-temperature equilibrium data are, in general, not very reliable. Although the lower-temperature (<2000°C) phase relationships in the Nb-Mo-C system are similar to those found in Ta-W-C, a cursory thermodynamic analysis of the equilibria indicated4 that complete solid-solution formation between Mo2C and Nb2C should not occur at higher temperatures. The present work was conducted in order to experimentally verify these expectations and, in addition, to provide phase equilibrium data in the melting range of the alloys. In the boundary systems, niobium and molybdenum are known to form a continuous series of solid solutions.576 The continuous solubility was also confirmed by Kornilov and Polyakova,7,8 who also observed a minimum melting point at 22 at. pct Mo and 2345°C. The phase diagram investigations of the Nb-C system by Storms and Krikorian9 and Kimura and Sasaki10 were recently supplemented by Rudy et al.11,12 The system contains a high-melting monocarbide with the B1 structure, Table I, and a subcarbide, Nb2C, which exists in at least two different states of sublattice order at low temperatures47"-&apos;3 and a disordered state above approximately 2500°C.11,12 The melting-point measurements by Rudy et al .11,14 are in close confirmation of the data by Kimura and Sasaki.10 The rather complex phase relationships in the Mo-C system were only recently Clarified.15,18 The system is characterized by three congruently melting, intermediate phases, MozC, ? MoC1-x and a Mol-,, Table I, of which only Mo2C is stable at temperatures below 1650°C. Substoichiometric MozC exists in several states of sublattice order which interconvert in homogeneous phase transitions. Hyperstoichiometric compositions cannot exist in the ordered state. Upon cooling through a critical temperature range, the

Jan 1, 1968

By H. M. Faust

THERE are a number of different types of power plants. Some use coal to generate steam, others use oil or gas either in the form of steam or internal combustion equipment, while still others avail themselves of water power as a source of energy. A general comparison of the relative power production with different sources of energy in the United States, for several different years is set up in Table 1. This table shows that coal was used to generate 85.6 per cent of the total heat power requirements of 1909, and only 59.2 per cent of the 1930 requirements. The increasing proportion of modern heat energy generated by the use of fuel other than coal is apparent. If coal is to maintain its importance as a source of heat energy, the necessity for its improved perform-ance, in which preparation plays an -important part, cannot be stressed too strongly.

Jan 1, 1933

By William E. Horst, John H. Bassarear

A technique is described which simplifies the standard procedure for measuring the Bond work index of a specific ore and illustrates how to overcome the strict requirements regarding feed size distribution normally encountered in operating plants. Actual results obtained from various process streams in a copper concentrator are presented and the grindability data are discussed in relation to the observed plant performance. This type of information can be used to gain a better understanding of plant behavior and to assist in the evaluation of plant modifications and process control studies.

Jan 1, 1977

By Peter Stubbs

Mr. Agelopas is to be congratulated on a fine paper. Although the presentation was simple and concise, you will all appreciate that a great deal of hard work went into the development of this highly successful repair method. Earlier this year Bethlehem invited a group of our people to witness lug repairs at their Sparrow&apos;s Point plant. We have since made lug replacements on a trial basis using their method. The repaired moulds are now back in service. We will compare their performance with regular moulds and with moulds repaired by a technique developed by Dofasco weld shop personnel. I would like to explain briefly some of the various types of ingot mould repairs presently undertaken at Dofasco. The first problem will be familiar to most of you. The lower inside edge of a mould wall may be damaged by spalling, a runout or by the washing action of steel deflected from a badly worn stool cavity. We repair this type of damage by welding.

Jan 1, 1972

By John Sasadi, Karl Heinz Zepter, Leonard Sugin, Roger L. Hulette

Mt. Newman Mining Co. is now completing an expansion program, begun even before initial construction was complete, which will result in the ability to ship up to 35 million tpy of iron ore by early 1973. Located in the Pilbara region of Western Australia, the mine at Mt. Whaleback is about 700 road miles north of Perth and 265 railroad miles south of the port facilities at Port Hedland. Development of the tertiary crushing and screening facilities best illustrates the orderly, but rapid, sequence through which the capacity of the port loading terminal has been expanded. When the present program is completed, crushing and shiploading capability will reach - - 35 million tpy. Operations commenced in 1969 with 3 crusher lines in service; and despite the 5-million annual ton rating, 6.46 million tons of ore were shipped during the first full year of operation. With continuing increase in ore sales, expansion to an annual capacity of 12 million tons was authorized, and installation of two more crusher lines was begun. As a part of this program, provision for installation of a sixth crusher at some future date was included in the planning; but before construction was completed, new ore sales contracts demanded further expansion to an annual rate of 20 million tons, and the sixth crusher line was authorized. The distributing and collecting conveyors had been designed for extension in length and increase in capacity, therefore, conveyor service was provided for the additional crushers with additional belting and hardware only.

Jan 6, 1972

By A. C. Milner

In a gold standard world which possesses insufficient metal to meet the every-day needs of all, confidence becomes the vital factor, the very foundation upon which the machinery for the expansion of gold into currency, and credit, rests. The gold supply, affected by many influences, moves constantly from one point to another, but not always to that point where it is most needed. In the period 1928-1930, the combined gold holdings of the United States and France increased $1,370,936,-000, and this with new gold adding only $600,000,000 to the monetary gold stock.Theref ore, the gold stocks of other countries must have been depleted during the period by $770,936,000. This uncontrolled shifting throws the delicately adjusted instrumentalities of both credit and commerce out of equilibrium. If a given nation&apos;s gold stock shifts so as to bring it substantially below the legal reserve ratio set up against it for currency issues, the effect can easily extend to the currency issues and banking credit volume of one or more nations which may have based their gold exchange standards upon the gold stock of such nation. Thus the substitution of paper based on gold in place of the actual gold is an inflation of the currency, which carries through into an uncontrolled pyramiding upon the entire machinery of credit based on gold. In 1929 Europe, South America, Africa and Asia had overissued currency based on gold. America, Oceanica and Japan, which have not overissued their gold currencies, would in normal times require their entire present gold stocks and, as Continental Asia is largely upon a silver credit basis, from a domestic standpoint, it would appear that the gold problem is not so much one of maldistribution, as it is one of inadequate supply. It would appear that some method of increasing greatly the velocity of gold, within the safe reserve point, should be devised, or that silver, of which estimates indicate that 7,000,000,000 oz. are available for

Jan 1, 1931

By Raymond Mancha

A TEST of any fan requires the determination of such data as fan pressure, air volume handled by the fan, and power input to the fan shaft. When testing operating mine fans of the centrifugal type, test methods have been employed, for the sake of convenience, that permit great latitude in detail of procedure resulting in wide variance in results by different investigators. Some controversial aspects of field fan testing are the result of past failure to define dearly the various forms of fan pressure and to a lack of understanding of the accurate procedure for the measurement thereof. Also, the anemometer for air-volume measurement, although convenient, if carelessly used and maintained is subject to a wide error range with variation in method of application and in instrument accuracy. The appearance of the axial-flow type of mine fan offers the possibility of refinements in field testing that were impractical with the centrifugal fan. First of all, the fan inlet and outlet are more sharply defined, giving loser agreement as to just where the fan begins and ends; thus there is less disagreement as to the proper location for measurements of fan pressure. The area of passage into the inlet of an axial-flow mine fan usually constricts, causing high air velocities with accompanying steadiness of flow. Thus the fan inlet offers an ideal location for accurate air-volume measurements with the Pitot tube, the proper use of which is well established by code. Thereby the controversial aspects of such measurements are eliminated. Use of the Pitot tube also facilitates a more accurate measure of fan pressure, since the individual pressures measured can be properly weighted, as will be explained later. Determination of power input to the axial-flow mine fan operating in the field is subject to the same inaccuracies as with the centrifugal fan if the axial-flow fan is also belt driven. However, because of the higher rates of rotation usual with axial-flow fans, direct-driven units are more numerous and it is unnecessary to assume a drive efficiency, thus eliminating one possible source of error. It is the purpose of this paper to define and explain the various types of pressure measurements involved in a field test of an axial-flow mine fan, and to further explain the proper use of the Pitot tube when measuring pressures and volumes. DEFINITION OF FAN PRESSURES The two fan pressures most commonly discussed are fan total and fan static pressure, each of which has the same meaning regardless of whether the fan is blowing, exhausting, or blowing and exhausting, as in the case of a fan with ducts connected to both outlet and inlet. Fan total pressure is the amount by which the total pressure of the air delivered by the fan exceeds the total pressure of the air received by the fan. This pressure is a measure of the maximum amount of the work done on the air by the fan that is available for external use.

Jan 1, 1942

By William E. Schoeneck

This paper presents the problem of oil-well abandonment as a group of studies involving the compilation of physical well data, the use of special curves, maps, and interpretative Procedures, in order that operations can be analyzed and means for reducing costs can be effected. Methods for the calculation of the economic limit of production and resultant oil reserves are suggested in order that profitable production may be continued and premature abandonment prevented. INTRODUCTION Purpose Extensive studies have been made and much has been written on the procedures for prospecting, drilling, completion, production and repair of oil wells, but the writer has long felt the need for a study of the procedure that should be followed when considering the abandonment of a well. The production from numerous well bores of a fluid material (a circumstance peculiar to the oil industry) that is continually decreasing in quantity leads to an increasing ratio of operating cost to production. It is for this reason that oil fields are not abandoned as a whole and detailed consideration of each well is required before it can be determined whether more is being expended than will be returned On any well or lease in question. It is the purpose of this paper, therefore, to compile, correlate, and present all matters worthy of consideration in the problem of oil-well abandonment; to suggest interpretative procedures based on such compilations, to the end that reliable estimates of reserves and life may be obtained; to show, as a result of such interpretative procedures, the possibilities for corrective measures conducive to economical production, thereby extending both profitable reserves and length of life. Scope and Approach Compiling data and outlining a study having the complexity of the problem at hand are naturally subject to the personal experiences of one who undertakes the study; however, the chosen approach and grouping of the subject material may be helpful in the consideration of abandonment problems. Consideration has been given to wells that make gas and water incident with the production of oil; but consideration has not been given to either gas wells or condensate-producing wells, for wells of the latter type have sufficient problems to warrant separate investigation. The major subdivisions of this paper-— physical considerations and economic considerations—do not imply that either of these phases can be considered independently, but rather that the two are mutually dependent and are the component parts of an engineering study.

Jan 1, 1946

By William E. Schoeneck

This paper presents the problem of oil-well abandonment as a group of studies involving the compilation of physical well data, the use of special curves, maps, and interpretative Procedures, in order that operations can be analyzed and means for reducing costs can be effected. Methods for the calculation of the economic limit of production and resultant oil reserves are suggested in order that profitable production may be continued and premature abandonment prevented. INTRODUCTION Purpose Extensive studies have been made and much has been written on the procedures for prospecting, drilling, completion, production and repair of oil wells, but the writer has long felt the need for a study of the procedure that should be followed when considering the abandonment of a well. The production from numerous well bores of a fluid material (a circumstance peculiar to the oil industry) that is continually decreasing in quantity leads to an increasing ratio of operating cost to production. It is for this reason that oil fields are not abandoned as a whole and detailed consideration of each well is required before it can be determined whether more is being expended than will be returned On any well or lease in question. It is the purpose of this paper, therefore, to compile, correlate, and present all matters worthy of consideration in the problem of oil-well abandonment; to suggest interpretative procedures based on such compilations, to the end that reliable estimates of reserves and life may be obtained; to show, as a result of such interpretative procedures, the possibilities for corrective measures conducive to economical production, thereby extending both profitable reserves and length of life. Scope and Approach Compiling data and outlining a study having the complexity of the problem at hand are naturally subject to the personal experiences of one who undertakes the study; however, the chosen approach and grouping of the subject material may be helpful in the consideration of abandonment problems. Consideration has been given to wells that make gas and water incident with the production of oil; but consideration has not been given to either gas wells or condensate-producing wells, for wells of the latter type have sufficient problems to warrant separate investigation. The major subdivisions of this paper-— physical considerations and economic considerations—do not imply that either of these phases can be considered independently, but rather that the two are mutually dependent and are the component parts of an engineering study.

Jan 1, 1946

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members) Graduate mining and metallurgical engineer now open for engagement. Member, 38 years old, married, 19 years&apos; experience in United States, Europe, South America, Africa, in exploration work, surveying, assaying, mining, milling, ore-dressing, construction and management. Four languages mastered. No. 355. Member, aged 35, technical graduate, desires position -as superintendent or assistant superintendent of spelter or zinc oxide furnaces, or both. Gas producer experience, zinc metallurgical and laboratory experience. Can handle men. No. 356. Member, also Assoc. Mem. Am. Soc. of C. E.; excellent technical education, and best of references covering twelve years in responsible charge of work; experienced in surveys, construction, prospecting, mine examination and development and irrigation work; speak Spanish fluently, and can write a good report. Good executive. Available during June. Age 34; married. No. 357.

Jan 6, 1917

No. 347.-A South African development company will shortly require the services-of a mill superintendent, who has a general knowledge of concentration, particularly of flotation, and is able to take charge of a copper concentrator treating 15,000 tons per month and employing 200 natives and a small number of white men. Salary is £60 per month to start, and the company supplies furnished room or house, including free light, free water and free sanitary service, together with one native house servant. A contract will be made for 6 months, and notice of 3 months by &apos;either party will be required to terminate the engagement after 6 months. An allowance of £75 for-traveling expenses will be paid on arrival in South Africa to a single man, or £125 to a man who brings his family. Salary begins upon arrival in South Africa, and no allowance will be made for return traveling expenses. No. 349.-A Canadian university wishes to engage a man to teach non-ferrous metallurgy and ore-dressing as well as to direct research work. The instruction work covers 7 months but the research work is continued throughout the year. To a suitable man the rank of professor will be granted. Applicants are requested to state education, experience, salary desired and any other particulars that might assist in selecting a man for this position. No. 350.-Wanted, 60 engineers for ordnance training school, month&apos;s training. Salary for first three months $1200 to $1500. After 3 months, up to $2400.

Jan 11, 1918

By P. B. Liebermann

The resistance to motion offered by mine cars is caused principally by: Rolling friction, flange friction, bending rails, bearing friction and wind resistance. With proper construction and with a fair amount of attention and care, that is, under favorable conditions, the first three items cannot be greatly improved. The wind resistance ordinarily is negligible on account of the slow speeds commonly used. The bearing friction, however, is a variable item, depending upon the design, the bearing material, the lubrication, the location (whether in wheel-hub or on car-body) and the alignment. Under the most favorable conditions the bearing friction will reach a lowest possible value. By the development of a successful anti-friction mine-car bearing this lowest value has been improved to such an extent as to affect the whole system of mine haulage. After being satisfied of their durability and certainty of operation, any investigation into the advantages of anti-friction bearings for mine cars will have to be based upon reliable information as to the saving in power of such bearings. While numerous tests have been made in this direction, the results have not always been convincing, principally because of the rather crude methods that were employed. These crude methods are the main cause of the wide variations existing in regard to the exact amount of the frictional resistance. Frequently an ordinary spring balance is used and the pull necessary to move a certain car or train of cars is obtained by a number of readings. Such spring balances necessarily have a coarse graduation and the continuous vibration and fluctuations to which they are subjected make them highly dependent upon the individual observer. Further, they must be frequently calibrated. Sometimes these tests were made without regard to acceleration, speed or even grade. The method of using an electric locomotive as a testing device is perhaps more open to criticism than the spring-balance method, because it introduces additional sources of error: The varying electrical and mechanical losses in the locomotive. Also, such a measurement always includes the power necessary to move the locomotive itself. This means a considerable amount of figuring, and the results due to the various multiplications and corrections may be of little value, for obvious reasons. When figuring the drawbar pull from the electrical

Jan 1, 1917

By Owen W. Ellis, Telfer E. Norman

The use of cadmium as a base for bearing metals is one of the most interesting recent developments in this field. It has caused a strong demand for cadmium and a marked rise in its price. It appeared to the authors, therefore, that the situation might be relieved for users if acceptable substitutes could be developed. A preliminary investigation has revealed that to some extent mercury may be substituted for cadmium. Whether its use is justified cannot be stated at this time. Most of the authors&apos; work has indicated that the addition of mercury to alloys of cadmium and nickel detracts from their desirable physical properties; but this work has not been extended to cover service tests, which might reveal that the addition of low percentages of mercury to the cadmium-base alloys would improve their performance. The results of tests made by the authors are therefore briefly summarized for this paper. Table 1 gives the proportions of the metals used in preparing the alloys. After preparation of these alloys, th composition was checked by chemical analysis. Particular care taken to ensure that the nickel content did not vary appreciably from 1 per cent.

Jan 1, 1938

By Owen W. Ellis, Telfer E. Norman

The use of cadmium as a base for bearing metals is one of the most interesting recent developments in this field. It has caused a strong demand for cadmium and a marked rise in its price. It appeared to the authors, therefore, that the situation might be relieved for users if acceptable substitutes could be developed. A preliminary investigation has revealed that to some extent mercury may be substituted for cadmium. Whether its use is justified cannot be stated at this time. Most of the authors&apos; work has indicated that the addition of mercury to alloys of cadmium and nickel detracts from their desirable physical properties; but this work has not been extended to cover service tests, which might reveal that the addition of low percentages of mercury to the cadmium-base alloys would improve their performance. The results of tests made by the authors are therefore briefly summarized for this paper. Table 1 gives the proportions of the metals used in preparing the alloys. After preparation of these alloys, th composition was checked by chemical analysis. Particular care taken to ensure that the nickel content did not vary appreciably from 1 per cent.

Jan 1, 1938

By AIME AIME

NO other man now on the Institute&apos;s Board has a record of long service to his professional society comparable with that of Karl Eilers. He joined in 1888; he was a Councilor as far back as 1909, a Vice-President as early as 1912, and for the last ten years has been continuously a Director and Treasurer. It seems fitting, therefore, that he is the only member of the present Board that is also an Honorary Member of the Institute. Karl Emrich Eilers was born near Marietta, Ohio, Nov. 20,,1865, which makes him 71 years old. Columbia School of Mines gave him his E.M. in 1889, after which

Jan 1, 1937

By William L. Saunders

Many members of the Institute, who participated in the visit made, during the Bethlehem meeting of February, 1906, to the shops of the Ingersoll-Rand Company, at Phillipsburg, N. J., inspected with interest the new Electric-Air drill, which the company had set up for the purpose of showing it in actual operation to American mining engineers. At the request of the Secretary of the Institute, I promised at that time to prepare a paper for our Transactions, describing the construction and advantages of the machine. But such a paper would then necessarily have contained much that was only expected or claimed by the designers and manufacturers of the drill, and not yet incontrovertibly proved by varied and long-continued practice. However moderate such statements might have been, they would have given inevitably to the paper, to some extent at least, the air of a prospectus, rather than of a technical contribution. I therefore decided, with the Secretary&apos;s approval, to postpone the writing of the promised paper until it could set forth the results of adequate actual practice, as well as the latest details of construction, etc., based upon practical experience. That period has now arrived. The Electric-Air drill has been exhaustively tested in the field, under varied and arduous conditions and upon the hardest rocks. It is now fairly in the field; its merits and performances are matters of unimpeachable record, and its place among established competitors can be definitely determined. As a representative of the Ingersoll-Rand Co., as well as a member of the Institute, I may be permitted to add that my company, being largely interested in the manufacture of air-coxpressors and machinery driven by compressed air, has no desire to injure its own business by claiming for this new machine that it should immediately supersede all existing applications of pneumatic transmission of power for drilling. On the

Jan 1, 1908

By G. J. Borbely, E. A. Devuyst, V. A. Ettel

Introduction Of the techniques reported for cyanide removal from effluents, alkaline chlorination is the most common (Fisher and Wasser, 1969; Reidt, 1969). Shortcomings with this technique are the high reagent costs, chlorine contamination, and potential formation of cyanogen chloride. Chemical oxidation methods are also not suitable to remove cyanide from effluents containing sulphides in suspension, such as flotation tailings. An inexpensive method for removing cyanide, combined cyanide and related species from waste waters has been developed in Inco laboratories. The method is based on the use of sulfur dioxide (or a sulfite), lime, and air as the reagents. The decomposition reactions of cyanide, combined cyanide, and related species are catalyzed by copper in solution. Complete removal of cyanide species, most of which are oxidized to cyanate, is obtained by treating copper containing cyanide effluents with sulfur dioxide-air mistures while maintaining the pH between 6 and 10 with addition of lime. The new approach can also be applied to selective destruction of cyanide and combined cyanide in effluents containing sulphides in suspension, such as pyrrhotite. Again, a sufficient amount of dissolved copper must be present or added. Metals and precious metals present in the effluents are recovered as hydroxides by adjusting the pH of the treated effluents to about 9-10. Using the new method, the anionic species are removed in the following order: Free CN- > Complex CN- > Thiocyanate The above removal sequence is unusual as oxidants such as chlorine and ozone oxidize thiocyanate preferentially over the combined cyanide.

Jan 1, 1985