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By D. R. Parrish, T. M. Geffen, R. A. Morse, W. W. Owens

Laboratory studies of several factors affecting measurements of relative permeability were made using the three-section plastic-covered core technique. Results show that the core assembly, properly constructed, will perform as a single unit, and that the testing technique will, under suitable conditions of pressure gradient, gas expansion, and migration of partial water saturation, permit measurement of flow characteristics not affected by technique. Wettability equilibrium is readily established in cores exhibiting strong wetting preference to water or oil when initially saturated with water. Laboratory tests must be conducted so that saturation changes represent those that occur in the reservoir. Immediate implications of saturation history are (1:) that the possibility exists of increasing the displacement efficiency of solution gas drive reservoirs over the natural process, and (2) residual gas saturations following water flooding in gas or gas condensate reservoirs will be 15 to 50 per cent pore space rather than 1 to 11 per cent as generally believed. INTRODUCTION Solutions of petroleum reservoir problems pertaining to production performance require the use of true relative permeability characteristics. 'This relationship of fluid conductivity and saturation has been obtained by reservoir engineers in four ways, namely: 1. From past gross reservoir performance and the extrapolation of this data based on experience,1,2 2. By using published fluid flow relationships obtained in laboratory studies on general type porous materials,3, 4, 5 3. By attempting a mathematical derivation of flow behavior," using some experimentally obtained characteristics of reservoir rocks, and 4. By laboratory flow tests using representative rock samples of a reservoir. The first three methods listed above have shortcomings which make their use limited or questionable. Production characteristics of only certain processes are obtained from field data and these are not available at the beginning of a reservoir's producing life, at which time they are desirable. It is fortuitous if general fluid flow characteristics obtained experimentally have accurate application to specific field problems. Also, it is felt that at this time there is not sufficient knowledge of the flow behavior of oil, water, and gas in porous materials to enable applicable analytical description of this to be made based on other measured rock characteristics. Measurement of relative permeability in the laboratory offers the only direct method subject to adequate checking for determination of flow characteristics applicable to field problems. Primarily, this paper deals with laboratory experiments to establish the effects of several factors on the measurement of relative permeability and the practical significance of this knowledge. Laboratory flow tests are essentially model studies; the gross reservoir being represented by a small rock sample. It is necessary to simulate in experiments all the factors of importance which influence flow in the reservoir, as well a.; to eliminate effects peculiar to the model studied to assure measurement of valid flow behavior. Factors which affect the measurement and behavior of fluid flow in porous materials have been studied by other investigators.3,7,8,9,10,11 This analysis is not intended to evaluate fully all factors involved, but to establish first the validity of measurements by the technique used and then study flow behavior under various conditions. The studies reported are as follows: 1. Effects of pressure gradient, 2. Effects of gas expansion in tests conducted at near atmospheric pressure, 3. Effects of migration of a partial water saturation in oil-gas-water systems, 4. Effects If wettability characteristics of the system. and 5. Effects of the fluid saturation history. The first three are important only in laboratory measure-

Jan 1, 1951

During the past 20 years the Westinghouse Electric & Manufacturing Co. and the General Electric Co. have collected a valuable library of some 9000 volumes on electricity. The collection was intended especially for use in patent searches and is particularly rich in patent material. Files of all the principal patents relating to electric light acid power issued by America, England, France and Germany, are present, together with copies of the patents owned or controlled by the two companies. Another feature, and one of unusual value, is a series of volumes containing the records of the important adjudicated patent cases of these companies and their predecessors during the past 25 years, and forming a storehouse of electrical history. There are also files of about 100 electrical periodicals. It is a pleasure to announce that this collection has now been presented by the owners to the Engineering Societies Library. This gift, which was arranged through Mr. Charles A. Terry, Vice-president, Westinghouse Electric & Manufacturing Co., and Mr. Charles Neave, Counsel,

Jan 7, 1918

By E. H. Rose

The question is often pondered whether the flotation process is still an art or has become a science. The fact is that flotation is a science in so many variables that only art can blend them. It is demonstrable that no less than one hundred variables are involved in any flotation operation, most of them immeasurable on a routine basis. The behavior of every one of them is always governed by orderly and unchanging law, as no man can doubt. There is nothing truly indefinite about that behavior; the only indefiniteness is in our knowledge of it, either in general or from hour to hour in the circuit. In dealing with a simultaneous equation in, say, one hundred variables, all not only affecting the outcome to some degree but many influencing each other as well, it is small wonder that the mineral-dressing profession presents a case history of debate and controversial opinion. The statement of the subject of this symposium—a symposium on flotation machines—seems to delimit and define the matters to be considered and at least the general nature of the conclusions sought. Nevertheless, in such a meeting it is not possible to meditate upon all the variables that do in one way or another affect performance of flotation machines. To attempt it would be much like trying to operate a hundred-ring circus. Perverse variables being what they are, one could expect the elephant in ring 36 to squirt a trunkful of water at the tightrope performer in ring 37 to ruin that artist's act, just as our learning to depress pyrite in the early 1920's ruined the act of the formerly faithful old Callows. Honest Disagreements Selective flotation dates from 1922 or 1923, when several plants established their regular flotation operations on a selective basis. Since then, two decades of efforr have gone into the development of better and better flotation machines. Many have come and gone. The competition has simmered down to perhaps a dozen machines, each one of which is staunchly defended by some operators as being the best for their particular jobs, and as scornfully dismissed by at least a few others elsewhere as being positively the poorest for theirs. These disagreements are honest disagreements, honestly arrived at after plenty of sweat. In many a flotation plant, one machine has been tried out against another under conditions as fair as they could possibly be made. Sometimes the results are on a par but more often one machine shows a consistent and unmistakable margin of superiority over the other. In equally honest and enlightened tests, machine A may win over machine B in one place, and machine B over machine A by as great a margin in another. This paper purposes to identify some of the more prominent reasons why this is so,

Jan 1, 1947

By E. H. Rose

The question is often pondered whether the flotation process is still an art or has become a science. The fact is that flotation is a science in so many variables that only art can blend them. It is demonstrable that no less than one hundred variables are involved in any flotation operation, most of them immeasurable on a routine basis. The behavior of every one of them is always governed by orderly and unchanging law, as no man can doubt. There is nothing truly indefinite about that behavior; the only indefiniteness is in our knowledge of it, either in general or from hour to hour in the circuit. In dealing with a simultaneous equation in, say, one hundred variables, all not only affecting the outcome to some degree but many influencing each other as well, it is small wonder that the mineral-dressing profession presents a case history of debate and controversial opinion. The statement of the subject of this symposium—a symposium on flotation machines—seems to delimit and define the matters to be considered and at least the general nature of the conclusions sought. Nevertheless, in such a meeting it is not possible to meditate upon all the variables that do in one way or another affect performance of flotation machines. To attempt it would be much like trying to operate a hundred-ring circus. Perverse variables being what they are, one could expect the elephant in ring 36 to squirt a trunkful of water at the tightrope performer in ring 37 to ruin that artist's act, just as our learning to depress pyrite in the early 1920's ruined the act of the formerly faithful old Callows. Honest Disagreements Selective flotation dates from 1922 or 1923, when several plants established their regular flotation operations on a selective basis. Since then, two decades of efforr have gone into the development of better and better flotation machines. Many have come and gone. The competition has simmered down to perhaps a dozen machines, each one of which is staunchly defended by some operators as being the best for their particular jobs, and as scornfully dismissed by at least a few others elsewhere as being positively the poorest for theirs. These disagreements are honest disagreements, honestly arrived at after plenty of sweat. In many a flotation plant, one machine has been tried out against another under conditions as fair as they could possibly be made. Sometimes the results are on a par but more often one machine shows a consistent and unmistakable margin of superiority over the other. In equally honest and enlightened tests, machine A may win over machine B in one place, and machine B over machine A by as great a margin in another. This paper purposes to identify some of the more prominent reasons why this is so,

Jan 1, 1947

By E. H. Rose

THE question is often pondered whether the flotation process is still an art or has become a science. The fact is that flotation is a science in so many variables that only art can blend them. It is demonstrable that no less than one hundred variables are involved in any flotation operation, most of them immeasurable on a routine basis. The behavior of every one of them is always governed by orderly and unchanging law, as no man can doubt. There is nothing truly indefinite about that behavior; the only indefiniteness is in our knowledge of it, either in general or from hour to hour in the circuit. In dealing with a simultaneous equation in, say, one hundred variables, all not only affecting the outcome to some degree but many influencing each other as well, it is small wonder that the mineral-dressing profession presents a case history of debate and controversial opinion. The statement of the subject of this symposium-a symposium on flotation machines-seems to delimit and define the matters to be considered and at least the general nature of the conclusions sought. Nevertheless, in such a meeting it is not possible to meditate upon all the variables that do in one way or another affect performance of flotation machines. To attempt it would be much like trying to operate a hundred-ring circus. Perverse variables being what they are, one could expect the elephant in ring 36 to squirt a trunkful of water at the tightrope performer in ring 37 to ruin that artist's act, just as our learning to depress pyrite in the early 1920's ruined the act of the formerly faithful old Callows. HONEST DISAGREEMENTS Selective flotation dates from 1922 or 1923, when several plants established their regular flotation operations on a selective basis. Since then, two decades of efforr have gone into the development of better and better flotation machines. Many have come and gone. The competition has simmered down to perhaps a dozen machines, each one of which is staunchly defended by some operators as being the best for their particular jobs, and as scornfully dismissed by at least a few others elsewhere as being positively the poorest for theirs. These disagreements are honest disagreements, honestly arrived at after plenty of sweat. In many a flotation plant, one machine has been tried out against another under conditions as fair as they could possibly be made. Sometimes the results are on a par but more often one machine shows a consistent and unmistakable margin of superiority over the other. In equally honest and enlightened tests, machine A may win over machine B in one place, and machine B over machine A by as great a margin in another. This paper purposes to identify some of the more prominent reasons why this is so,

Jan 1, 1944

The Wheeler Condenser & Engineering Co., of Carteret, N. J., is now building a line of horizontal and vertical shaft centrifugal pumps for general services, as well as for condenser work.. This company has been building centrifugal pumps for over 20 years, most of them being used, however, in connection with condensers. The new line of pumps is suited for all services. A small motor-driven unit for tank or stand pipe operation is shown in Fig. 1. Referring to the sectional illustration (Fig. 2), it will be seen that this pump conforms to the most recent advances in centrifugal pump construction, having a two-part divided casing, with the suction and discharge nozzles in the lower half. The impeller is of the closed double-suction type, protected by labyrinth wearing rings. The shaft is protected from the water by bronze sleeves, which screw on to the shaft and extend clear through into the bearing bracket boxes. Bearings are of the ring-oiled type, and in the outboard bracket, is a ring-oiled thrust bearing, which is a refinement not usually found in double-suction

Jan 4, 1916

By Henry Knox

AMIDST the tumult and the shouting of the times, there are perceptible certain tendencies, quiet though serious, to take stock of the situation with a view to putting our house in order, and of these none is more encouraging than the awakening, interest in the higher education, and especially in technical education. Various committees of the professional organizations have cast much light on the matter and have pointed the way to progress and reform, but their scope is necessarily restricted by the requirements of precision and any excursion beyond these bounds must be undertaken by the unfettered individual who is free to rush in where responsible committees fear to tread. A discussion of the bearing of the higher education on character scarcely lends itself to objective treatment and yet, fraught as it is with imponderables and abstractions, the theme cannot be escaped in any com-prehensive scheme of education. The question is being pressed with growing insist-ence, why these United States, relatively to Europe, are deficient in intellectual output, and the ready reply, "Because America is a new country and Americans are too intent on developing their natural resources," is too facile and too false to carry conviction.

Jan 12, 1922

Joseph G. Butler, Jr., who represented this Institute on the American Industrial Commission to France, has presented a report to the Chairman of the Commission regarding the steel industry of France in war time. In this report Mr. Butler calls attention to the fact that only a few steel works were visited and that he thinks it probable that there are many plants in France more up-to-date than these. He noticed especially in the plants visited a dearth of labor-saving devices and not very great attention to the safety of the employees. He also noticed that the whole of the iron and steel interests in France are being used at the present time by the Government for war purposes, and he was told on good authority that the production has doubled since May, 1915. When the war is over, it is thought that France can send large quantities of iron ore from Algeria to the United States and take in return American coal to France, an interchange which would doubtless be of mutual advantage. In Mr. Butler's opinion the shortage of coal in France may be overcome to some extent by the use of water-power and by electrical processes for steel manufacture, and lie believes when the war ends France will be able to compete with other countries in exports of general iron and steel products, this trade being facilitated by the port improvements at Bordeaux and Marseilles. The French labor situation is much better than that in the United States from the standpoint of labor unions, but the wages are less and many women are now being employed to do men's work. This has a tendency to keep wages low, but is probably a war expedient only. The cooperation among manufacturers in France is at a high level and both local and national organizations exist for the discussion and voicing of trade problems. The national body which is a combination of the individual organizations is the Comite des Forges de France and it is an interesting fact that many of the members of this body are office holders under the Government, or heads of Government Committees which are organized to look after the very business in, which the individuals are engaged.

Jan 12, 1916

By Frank Firmstone

The piece of spiegeleisen, the analysis of which is given below, was collected by my father, together with various other specimens, while he was manager of the Glendon Iron Works. It bears a label stating that it was taken from a building in the town of Newton, New Jersey, erected in 1765 and torn down in 1863. The building belonged, in 1863, to T. N. McCarter, Esq. The label is in the hand-writing of Mr. McCarter, now deceased, well known as a member of the bar of northern New Jersey. The specimen was, no doubt, given by him to illy father, with whom he had business in 1863 and 1864. It is now in the metallurgical collection of Lehigh University. I know nothing further as to the history of the specimen, but there is no reasonable doubt that it was made from ore from the Andover mine, at the old charcoal-furnace which once stood at the village of Andover, about 5 miles south of Newton, on the Sussex railroad. It was probably broken from one end of a bearer over an open fire-place, is about 6 in. wide by 2.5 in. thick, has been cast in open sand and shows the charcteristic fracture of spiegeleisen rather low in manganese, as shown in Table I. One edge has been white-washed. Table I.—Analyses of Spiegeleisen Made from Andover Ore. 1. 11. Per Cent. Per Cent Graphite,.0.101 0.005 Combined carbon,... 4.529 4.212 Silicon,..0.037 0.294 Manganese,..... 5.760 3.750 Sulphur,.0.003 0.031 Phosphorus,.0.060 0.072 Iron,........ 89.440 91.570 99.920 99.934 I. Spiegeleisen made at Andorer (charcoal) furnace not later than 1765. IT. Spiegeleisen made from Andover ore at Phillipsburg, N. J., anthracire-furnwe, 185-. Both analyses were made by Dr. P. W. Shimer.

Jan 1, 1907

By Valentin R. Garfias

The world's petroleum production in 1929 is estimated at 1,479,335,-000 bbl., which represents an increase of about 157,000,000 over 1928, as compared with an increase of 61,000,000 bbl. in the previous year. During the present year a more definite policy of conservation has been seriously considered by the foremost executives of the companies controlling the bulk of domestic and foreign production, and the United States Government has taken an active interest in the development of this program. Definite steps have already been taken and the industry is gradually establishing a foundation for closer and more intelligent cooperation. The entire program, however, is still in a formative or experimental stage. Among other salient constructive steps may be mentioned the establishing of tentative agreements of unification in the price of oil products exported from the United States, the putting into effect of a gas conservation law in California, and the marked tendency towards consolidatlions of the various branches of the industry into larger units. The publication of the draft of the proposed petroleum law in Colombia and of the Mexican Labor Law, on the other hand, has created papre-hension and uncertainty. It is confidently expected, however, that these perliminary drafts will be materially modified before the laws arc promulgated, or otherwise they may destroy the interest they are intended to protect. United States Production in the United States, which remained stationary during 1927 and 1928, increased about 105,000,000 bbl., or 11.6 per cent. This increase is due primarily to deeper drilling in the California fields and to the discovery of new pools in Texas and Oklahoma. The progress of the conservation program was marked by the action of the Government in stopping further permits to drill on Government lands; by putting into effect early in September the California Gas Conservation Law, and by

Jan 1, 1930

BEFORE an audience which included many notable members of the engineering profession, the John Fritz Medal was presented to Senator Guglielmo Marconi on July 6, 1922, in the auditorium of the Engineering Societies Building, in New York. The medal was awarded for achievements in the development of wireless telegraphy, but all of the speakers emphasized the inventor's service to mankind, in saving life at sea, especially, as well as his remarkable scientific attainments. SIGNIFICANCE OF THE JOHN FRITZ MEDAL The John Fritz Medal is presented from time to time for notable achievements in applied science, as a memorial to the engineer and metallurgist whose name it bears, one of the charter members of the American Institute of Mining and Metallurgical Engineers. The medal fund, contributed by friends of Mr. Fritz, is administered by representatives of the four national engineering societies. Seventeen awards have been made to men of eminent distinction in the various branches of the profession of engineering, whose names are more familiar to the civilized world than are the names of most of the presidents of the United States. Four of the medallists were present on the evening of July 6: Dr. Elihu Thomson, the dean of the electrical engineers, General Goethals, Orville Wright, and J: Waldo Smith, who developed the New York City water supply, system. In opening the meeting, Dr. Comfort A. Adams, president of the Board of Award, said in part: The profession of engineering knows no national boundaries. That the engineers of this country sense this fact deeply is evi-denced by the absence of any limitations as to nationality in the award of the John Fritz Medal. The engineer is seeking for the truth wherever it may be found, and it frequently happens that the most helpful sugges-tions for the solution of a particular problem are the results of the work of men of other nationalities on the other side of the world, whom we have never seen. Thus through this long range interchange of information and of ideas, there has grown up a feeling of real kinship among the engineers of the civilized world, a sense of interdependence and of the need and value of cooperation, in wide contrast with the all too prevalent sense of conflicting interests, of racial and national antagonisms of bitterness and misunderstanding. We often think of the nations of the earth as separated by walls or barriers, of various kinds and of various heights. Some of these are the natural results of evolution, for example, differences of language, customs and traditions; while others are more artificial, being maintained by law and dictated by fear, greed, and shortsightedness or ignorance. There is deep conviction that the degree in which we can abolish these barriers is a true measure of our progress towards real civilization, and that the destruction of these barriers is the only method of attaining that world-wide peace for which every

Jan 8, 1922

By Dudley Homer

MINAS DE MATAHAMBRE, S.A. is a Cuban mining corporation with mines located in the Matahambre district about 100 miles westerly from Havana in the Province of Pinar del Rio. The port of entry is the subport of Santa Lucia on the north coast of Cuba. The mines are located six miles inland at the town of Minas de Matahambre. Minas de Matahambre and Santa Lucia are connected by a 9-mile automobile road, and a 30,000-ft. Leschen aerial tramway. At the subport of Santa Lucia the company maintains docks, concentrate bins, tugs, lighters, and miscellaneous shipping equipment. The power plant of the company is also located at Santa Lucia. Connection between the power plant and the mine is effected by a 30,000-ft. transmission line. In the town of Minas de Matahambre are located the mines, concentrator, shops, and warehouses. The con-centrates are transported to Santa Lucia by the Leschen aerial tramway. The mines are equipped with three shafts, viz., Nos. 1, 2, and 3. (Fig. 1.) No. 1 Shaft is a three-compartment vertical tim-bered shaft and has reached a depth of 1825 ft. This is the present main hoisting shaft. No. 2 Shaft is a four-compartment vertical shaft lined with steel sets and native hardwood lagging. Certain portions where the ground is heavy have been lined with re-inforced concrete. Practically all production will be hoisted eventually through this shaft. No. 3 Shaft is a three-compartment vertical timbered shaft. It has reached a depth of 1090 ft. Its purpose is for prospecting, ventilation, and handling men and sup-plies through the north section of the mine.

Jan 1, 1933

By Shosei Serata

Serious floor heave of up to 2.4 m in a 2.4-m high mine entry was eliminated by applying the stress control method of mining, as a last resort, at the No. 5 coal mine of Jim Walter Resources, Inc., in the Black Warrior coal basin near Birmingham, Alabama. Underground observation of the first 3-room entry created using the stress control method is discussed here. The behavior of the test entry, which eliminated the heave problem, is analyzed in relation to similar studies conducted in a salt mine under similar ground conditions by utilizing finite element analysis.

Jan 1, 1984

By W. A. Griffith

The fundamental principles and modern techniques of experimental planning and data analysis, applicable to any type of research, are particularly important in flotation experimentation. Since they constitute the modern science of experimentation, they should be among the working tools of any scientist, research engineer, or plant operator engaged in flotation investigates. This chapter is a review of these principles and techniques. Equipment and procedures for the actual conduct of experiments will not be discussed here since these subjects are well covered elsewhere in this volume. Neither will any attempt be made to impart a working knowledge of statistical methods of data analysis since this would be impossible in the space allotted, and many excellent texts are available to the diligent inestigator.1-4 The objective here is simply to interest the reader in the application of statistical techniques to flotation experimentation by illustrating their utility in situations frequently encountered, and to point out the principles of experimental planning necessary for their proper use. Any conscientious metallurgist engaged in flotation experimentation or operations is well aware of the inherent complexity of the flotation process, and of the often frustrating difficulties this introduces into experimentation. The raw materials normally treated by the process are complex both physi- cally and chemically, and often highly variable even when from the same source. The flotation process itself is characterized by a very large number of potentially important process variables. Many of these are beyond the con- trol of the metallurgist, and some cannot even be measured quantitatively with available instruments. Those which can be measured and controlled with reasonable precision often produce effects which are intricately interrelated. Not only are the variables many, but the physical and chemical mechanisms by which they function are imperfectly under stood. To compound the difficulty, experimental techniques are relatively crude. Controls are not very precise, and the human factor looms large in most flotation experiments. These situations lead inevitably to experimental data of a relatively low degree of precision or reproducibility. Some are inclined to think that these conditions are unique to flotation experimentation. They are not. The experimental problems met by the agronomist, the biologist, the social scientist, and others are equally complex. Investigators in these fields pioneered in the development of methods for handling just such situations by proper experimental planning and the application of statistical methods in the analysis of data. Their pioneering work has grown into a well established modern science of experimentation which has spread into every field of science. This science is based upon statistical

Jan 1, 1962

By Ronald F. Ayers

The basic research for this study was conducted by Battelle's Columbus Laboratories in 1974. The high-sulfur content of coal threatens to erode its competitive position in the future. The impact of sulfur removal on final costs of eastern interior coal lies at the very heart of this market analysis. An extensive market survey was conducted that considered both traditional coal markets as well as anticipated future markets. Competition for coal from this province considers low-sulfur Western coal, nu- clear power, international oil and coal trade, as well as Appalachian coal producers. Based on projections of future energy consumption under several scenarios, a comprehensive market forecast for eastern interior coal was made to 2040. The study upon which this paper is based was completed by Battelle's Columbus Laboratories for the U.S. Army Corps of Engineers in 1974. It is but part of an overall effort by the Corps to evaluate the costs and benefits to the nation of waterway improvements. This study is primarily concerned with future coal markets for production from those counties near the Wabash River in the heart of the Eastern Interior Province. An objective here is to consider a most pessimistic energy (and hence, coal) demand for planning purposes.

Jan 1, 1978

By H. A. J. Wilkens, H. B. C. Nitze

At the Atlanta meeting of the Institute in October,' 1895, some brief remarks were made by Mr. Wilkens on the above subject. It is the object of this paper to set forth the substance of these previous statements, embodying therewith additional information gained since that time, and a brief illustrated description of the method and means of the separation.* Lack of time will unfortunately not allow as complete a resume of the subject in all its phases, especially those relating to the scientific side of the question, as its novelty and importance would warrant, so that even this paper must be considered a preliminary one. It is hoped that at some future meeting of the Institute we may find an opportunity of presenting supplementary data of interest. The paradoxical title above used requires some explanation. The term " non-magnetic material " is applied to such substances as have heretofore been considered non-magnetic in the arts, more especially in the practice of ore-concentration. Scientifically, it has been shown by Faraday, Plucker, Wiedemann and other physicists that magnetism is an inherent property common to all substances, solid, liquid and gaseous, i.e., all suhstances are either attracted or repelled by the poles of a magnet, although ill the great majority of cases the manifestation of this

Jan 1, 1897

By G. L. Craig

In order to meet the unprecedented demand for copper it has proven necessary not only to develop every primary source, but also thoroughly to exploit the vast reservoir of metal in use that is not directly serving the war effort. To accomplish this, industry has been called upon to use its resourcefulness for developing methods of recovery that have not been previously utilized. It is in this connection that we have been asked to review the methods suggested for recovering the basic constituents of various types of the so-called clad or composite steels. As a background for a discussion of recovery processes, it seems appropriate to consider clad materials in general and their processes of manufacture. A composite steel has been defined as one consisting of two or more component parts of which the smallest shall comprise at least 3 per cent of the total mass. Clad materials or composites are produced commercially by several different methods of which the most important may be classified as: I. The Blacksmith or Forge Weld Method. This method is limited to carbon steels or low-alloy steels as the presence of even small amounts of common alloying metals prevent the formation of a satisfactory weld. The principle is the application of pressure to sections in contact at elevated temperatures. Because of the tendency of the iron to oxidize, borax is generally used as a flux to absorb the iron oxide. 2. Casting Process-In this method a composite ingot, billet or cake is produced by pouring one metal onto or about another. The bond may be accomplished by the action of the molten metal against a solid, in which case the bond may be referred to as mechanical; while in other instances alloying occurs at the interface producing an anchor by the formation of component parts of the two materials. 3. Cementation Process.-In this process any number of combinations of metallic and nonmetallic constituents which are mixed together may be used as a bonding agent. The combinations, whatever they may be, are placed between the materials to be joined and subjected to pressures at elevated temperatures to produce the desired bond. 4. Fusion Welding Processes.-Gas and electric joining for direct use or subsequent fabrication. 5. The, Assembly Process.-This method involves the joining together of prefabricated bars or plates followed by hot and/or cold working the assembly to the desired finished form. This method is advantageous in many cases because of its flexibility on small quantities as compared to the casting method. It is also possible to control the relative proportion of components more accurately. In this discussion we are concerned only with the scrap resulting from the manufacture of clad materials and our interest,

Jan 1, 1943

By W. H. Reck

Increasing use of flotation in modern beneficiation has resulted in a variety of froth handling methods. Froth must be handled mechanically to maintain common floor elevation, because pure gravity flow, stage to stage, makes for multiple level machine installations with higher first cost and less convenient operation. Bucket Elevator--Froth is collected by launder and goes to the feed entry of the elevator, below the floor. The bucket goes to the next treatment stage by gravity flow. The outstanding advantage is high efficiency of conveyance.

Jan 5, 1955

By W. Joseph Schlitt, Kenneth J. Richards, John D. Prater

Kennecott Minerals Company has developed a leach-hydrolysis route for treating flue dusts from copper smelters The flue dusts are acid leached in an oxygen atmosphere to solubilize copper and fix the arsenic, antimony, and bismuth as stable compounds Copper is recovered by cementation with Iron and the barren solution is recycled Molybdenum and other values may be recovered by modification of the basic flow sheet Results of bench scale and pilot plant tests are discussed in terms of the effect of operating parameters.

Jan 1, 1981

By C. D. Gilpin, Franklin Moeller

The application of electric power for driving mine hoists handling heavy loads at high speeds has recently been extended by the installation of what is probably the largest electrically driven hoist in this country at the Granite Mountain shaft of the North Butte Mining Co., Butte, Mont. While the weight of rock which is hoisted by this machine is not the largest now being handled by electric mine hoists, the speed of hoisting is so, and the combination of the high speed with the heavy load has resulted in a machine of considerable interest to all those actively engaged in mining. Aside from mere considcration of size, this installation deserves attention because of the careful attention given, not only to the question of economy of operation, but to the details of construction and installation of the entire equipment. The conditions to be met in this installation were as follows: Weight of rock to be raised per trip, 7 gross tons........... 15,680 1b. Weight of skip.......................................... 8,000 1b. Weight of cage.......................................... 1,800 1b. Maximum depth of hoisting.............................. 4,000 ft. Diameter of rope.......................................... 15/8 Total weight suspended on one rope from drum............. 42,000 1b. Normal hoisting speed.................................... 2,700 ft. per minute. Maximum hoisting speed.................................. 3,000 ft. per minute. Desired capacity-200 tons per hour from 4,000 ft. depth. The ore is mined in several levels and hoisting is carried on from the 800-ft. level down to the 2,700-ft., which is at present the maximum depth from which the ore is raised regularly. Development is proceeding and a depth of 2,900 ft. has already been reached. The rock is handled underground in cars holding % ton, and about 10 cars are the usual load for a skip. All of the ore is dumped into underground bins, which are of diffcrent capacities varying up to 250 tons. From the bins the ore is fed into the skips without passing into measuring pockets. At the surface the

Jan 1, 1916