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By E. B. Fitch, E. C. Johnson

The operating behavior of liquid-solid cyclones is outlined, together with the nature and range of the process results obtainable, to serve as a background for engineers wishing to consider application of this new process tool. BY now most engineers are familiar with the liquid-solid or Dutch State Mines cyclone. However, it should be helpful to know exactly what it is that the equipment does and what its limits are. Without going into cyclone theory, this paper will describe the operating characteristics of Dutch State Mines cyclones. These are manufactured under license in this country and sold under the trade-marked name of DorrClone. The physical construction of the liquid-solid cyclone has been covered in many papers,'-' the DorrClone in particular being described in some detail by Weems. Fig. 1 shows the unit in cross-section. The feed enters at C. The coarse, heavy particles are thrown centrifugally to the periphery and make their way down the wall to the apex where their rate of discharge as underflow is controlled by an adjustable rubber apex valve. As the apex diameter is decreased the solids build up behind the valve, producing a denser underflow. Meanwhile the fine particles are swept into the upward flowing vortex stream which exits as overflow through the vortex finder, F. Flexibility to produce the specific result desired in a particular process is achieved by providing means for varying the areas of the entrance, vortex discharge, and apex discharge. The entrance area may be varied by insertion of special shims. Vortex discharge area may be changed by use of different-sized vortex finders which are interchangeable. Similarly, the different sizes of apex valves are interchangeable and in addition each apex valve is variable down to about 60 pct of its maximum diameter. A most significant primary distinction to make is that although liquid-solid cyclones have been sometimes called thickeners, they actually are classifiers, and very potent ones. They are almost never thickeners in the special sense that many metallurgical engineers understand the term. There would be no profit in quibbling over the definition of a word, but when the application of cyclones is considered, it will help to understand the difference be- tween two mechanisms, one of which will be called classification, and the other thickening. In what is called thickening the fine solid particles present in the feed hold together by surface attraction during the sedimentation process. The loose network of particles thus held together constrains all particles to settle at approximately the same rate, the larger ones dragging the smaller ones down. As a result, pulp settles with a sharp line of demarcation between solids and a relatively clear supernatant liquid. Essentially all the solids, regardless of their fineness, pass into the thickened underflow, and a clear overflow is separated. In classification, on the other hand, the interparti-cle forces are relatively insignificant as compared to the settling force on the individual particles, and are insufficient to prevent independent movement of the particles. The coarsest, heaviest particles settle most rapidly through the pulp, passing more slowly settling fines. Particles coarser than the mesh-of-separation essentially all settle into the underflow, but if the feed contains any particles finer than the mesh of separation, at least part of them will appear in the overflow. A clear supernatant or overflow can be obtained only if there are no undersize particles present in the feed. Thus it will be seen that classification is impossible under ideal thickening conditions. The finer particles are pulled down at essentially the same rate as coarser particles, and there is no separation on the basis of particle size. The surface attraction holding the particles together in a thickener is usually feeble. Whenever the sedimentation force on any particle is strong with respect to the interparticle forces, that particle can pass through the tenuous structure and settle independently. There are at least four ways of making the sedimentation force strong, with respect to the interparticle forces, and obtaining classification. First, and most obvious, the particles may be large and heavy. Thus coarse sands settle out in a beaker or Dorr thickener ahead of the rest of the thickening solids. Second, the interparticle forces may be altered by physicochemical means; i.e., it is often necessary to add dispersing agents to destroy the interparticle forces and permit classification to take place. Third, the interparticle forces may be reduced by dilution of pulp. It is well known that to obtain the most efficient separation of

Jan 1, 1954

Joseph William Richards, was born in Oldbury, Worcestershire, England, on July 28, 1864, of English-Scotch parents, Joseph and Bridget (Harvey) Richards. In 1871, he came to this country with his parents. He attended the public schools of Philadelphia, Pa., where his father was a manufacturing metallurgist, and in 1882, graduated from the Central High School with the degree of A. B. The same year he entered Lehigh University, from which he received the degree of A. C. (Analytical Chemist) in 1886; M. S. in 1891, and Ph. D. in 1893. His connection with the university was continuous from 1887 until his death, and he therefore adds another to the list of names of men Prominent in the A. I. 11. E. who have helped to develop Lehigh University to the important position which it now occupies in mining and metallurgical education in respect of world-wide fame. It is fitting to recall in this connection that, Eckley B. Coxe, a fonnder of the A. I. M. E., four times its vice-president,, and president in 1878-79, was literally a pillar of the university for several years prior to his death; Thomas M. Drown, founder, vice-presi(lent, secretary for 11 years, honorary member, and president in 1897, was president of Lehigh University from 1895 to 1904; and Henry S. Drinker, founder, manager, vice-president, and honorary member, was president of the university from 1905 to 1920. Doctor Richards was no less active in both institutions. With the exception of the years 1886 to 1887, when he was superintendent of the Delaware Metal Refinery of Philadelphia, his professional life was devoted to the upbuilding of the metallurgical department of the university, in part through his continuous services as a member of the teaching staff, and in part through the international renown won for the department by his achievevements as author, investigator, expert and rerognizcd authority in metallurgy, especially the metallurgy of aluminum, metallurgical-chemical calculations, and electrometallurgy. He was assistant instructor in metallurgy and blowpiping in 1887; instructor, 1888-90; instructor in metallurgy, mineralogy and blowpiping, 1890-97; assistant professor, 1897--1903; professor of metallurgy, 1903-1921. He died at his home in Bethlehem, Pa., on Oct. 12, 1921, of heart failure. To the A. I. M. E., for a continuous period of a dozen years, his services were equally loyal and effective. He was vice-president, 1910-11, and 1916-17; councilor, 1912; dirctor, 1913-15; chairman of the Iron and Steel Clommittee, 191-1-21; he was one of the framers of the Insti-

Jan 1, 1922

Joseph William Richards, was born in Oldbury, Worcestershire, England, on July 28, 1864, of English-Scotch parents, Joseph and Bridget (Harvey) Richards. In 1871, he came to this country with his parents. He attended the public schools of Philadelphia, Pa., where his father was a manufacturing metallurgist, and in 1882, graduated from the Central High School with the degree of A. B. The same year he entered Lehigh University, from which he received the degree of A. C. (Analytical Chemist) in 1886; M. S. in 1891, and Ph. D. in 1893. His connection with the university was continuous from 1887 until his death, and he therefore adds another to the list of names of men Prominent in the A. I. 11. E. who have helped to develop Lehigh University to the important position which it now occupies in mining and metallurgical education in respect of world-wide fame. It is fitting to recall in this connection that, Eckley B. Coxe, a fonnder of the A. I. M. E., four times its vice-president,, and president in 1878-79, was literally a pillar of the university for several years prior to his death; Thomas M. Drown, founder, vice-presi(lent, secretary for 11 years, honorary member, and president in 1897, was president of Lehigh University from 1895 to 1904; and Henry S. Drinker, founder, manager, vice-president, and honorary member, was president of the university from 1905 to 1920. Doctor Richards was no less active in both institutions. With the exception of the years 1886 to 1887, when he was superintendent of the Delaware Metal Refinery of Philadelphia, his professional life was devoted to the upbuilding of the metallurgical department of the university, in part through his continuous services as a member of the teaching staff, and in part through the international renown won for the department by his achievevements as author, investigator, expert and rerognizcd authority in metallurgy, especially the metallurgy of aluminum, metallurgical-chemical calculations, and electrometallurgy. He was assistant instructor in metallurgy and blowpiping in 1887; instructor, 1888-90; instructor in metallurgy, mineralogy and blowpiping, 1890-97; assistant professor, 1897--1903; professor of metallurgy, 1903-1921. He died at his home in Bethlehem, Pa., on Oct. 12, 1921, of heart failure. To the A. I. M. E., for a continuous period of a dozen years, his services were equally loyal and effective. He was vice-president, 1910-11, and 1916-17; councilor, 1912; dirctor, 1913-15; chairman of the Iron and Steel Clommittee, 191-1-21; he was one of the framers of the Insti-

Jan 1, 1922

By D. R. Packard, J. D. Verhoeven

The resistivity us atom fraction relationships for dilute solutions of cadmium, mercury, and tin in molten sodium have been determined. With these data and the resistivity capillary-reservoir technique, the electro-transport mobilities, effective valences, and the diflusion coefficients of the three solutes have been determined. The mobilities are found to be higher than in other molten alloys by a factor of around 20. The results are compared to the Mmgelsdorf model for electrotrmtsport. The high values found for the mobility to diffusion coefficient ratio indicate that small quantities of the alkali metals should be susceptible to purification from many solutes by means of electrotransport. PASSAGE of a direct electric current through a liquid metal containing a solute will usually cause a relative motion between the solute and solvent atoms of the alloy. This electrotransport phenomenon may be described experimentally in terms of the mobility of the solute atoms, i.e., the drift velocity of the solute relative to the solvent per unit electric field. In dilute solutions of liquid alloys this relative mobility becomes a measure of the velocity of the solute with respect to the observer since the motion of the solvent is negligible. The mobility is a significant parameter in evaluating the potential usefulness of electrotransport for such things as purification or solute control upon solidification. Prior to around 1958, quantitative data for the mobility of solutes in liquid metals were restricted to some solutes in liquid mercury. Since that time ad- ditional data have been reported for the mobility of solutes in liquid mercury, bismuth, tin, and lead, as shown in Table I. In 1963 Drakin et al.11 reported some values of a transport number for mercury and thallium in molten sodium and potassium. When these values were converted to mobilities, it was found that the mobilities were higher than any of the previously reported values by a factor of around 20, as shown in Table I. Drakin's experimental technique did not eliminate the presence of back-diffusion and consequently his data were expected to be lower than the true values. The purpose of the present investigation was to determine the mobility of a number of solutes in molten sodium with an experimental technique which eliminates back-diffusion errors. EXPERIMENTAL The technique used to determine the mobility was a resistivity capillary-reservoir technique which had previously been used with a high degree of precision on Sn-Bi alloys.4 This technique consists of dipping the vertical Pyrex capillary cell shown in Fig. 1 into a molten bath of alloy while the bath and capillary are under vacuum. The capillary is then filled by intro-

Jan 1, 1969

By David C. Russell

The Department of the Interior used to be a quiet, noncontroversial, almost boring agency. It, after all is the fifth oldest of the Departments, and as an old line Federal agency it has studiously performed its preservation and resource management functions in a caretaker mode--though some would say more "undertaker" than "caretaker"--locking up the body and soul of America piece-by-piece. Yes, quiet, serene. That is until Jim Watt showed up. And we have all seen that version of Mt. Vesuvius which resulted--only it was the environmentalists who blew their tops. Ronald Reagan chose Jim Watt as Secretary of this fine old agency to prove that one-third of our Nation's land and over a billion acres on the Outer Continental Shelf can work for this Nation. At the foundation of President Reagan's charge to Secretary Watt is a belief in the tenets of the free enterprise system, and in the individual freedoms upon which this country was founded. There are those who don't share this belief in democracy and free enterprise, and those who believe this 205 year experiment called the United States of America will fail. Nikita Krushchev said "we will bury you"--obviously he didn't agree with our system. An Italian sociologist, Franco Ferrorotti, said bureaucratic stagnation will kill capitalism. Certainly we have all felt the ravages of bloated bureaucracies. Perhaps one indicator in the United States is the Federal Register, that daily compilation of Government's largesse. In 1970, 20,000 pages of the Federal Register were published. A decade later, in 1980, that volume had quadrupled to 80,000 pages. The Federal bureaucracy can stagnate from excessive budgets as well. The Interior Department spent $60 million on administering Federal coal leasing in 1981. That's nearly two bits a ton for every ton of coal leased in 1981. You wouldn't stay in business very long if your administrative overhead on inventory was that outrageous. But the pessimism of our critics is apparent from more than red tape and bloated budgets. For decades America has been fasting--consuming too little of America's wealth of minerals, subsisting instead on a diet heavily reliant upon mid-east oil, with little emphasis or concern for inventorying and developing domestic energy and mineral resources. Economics--yes. But short-term, short-sighted economics. Excessively dependent upon foreign imports, of oil, cobalt, chrome and other strategic minerals, the U.S. measures its time before another embargo--or fallen Shah, or Soviet manipulation, or Saudi shift, or, as we witnessed in Egypt, assassination--an untimely loss to mankind and efforts to bring peace to the troubled mid-east. These disruptions, in addition to their tragic human tolls, impair the free world's security. Huge chunks of the United States have been locked away in dozens of single land use categories in the name of conservation, with only the foggiest idea of what resources might be denied the American people-and this at a time of unacceptable levels of energy and strategic mineral imports. More than half and perhaps two-thirds of all Government-owned lands are totally withdrawn from or severely restricted to development under the mining and leasing laws. We must continue to rid Government of the overly zealous restraints which have been keeping us from drawing upon that which can help restore our economy and national security. When we assumed responsibility, the United States was dependent on foreign sources for about 40 percent of its oil. In 1981, our oil import bill was approximately $83 billion--nearly 17 times what it was in 1972. Our reliance on foreign sources for essential minerals is even more disturbing. We must look to other countries--some unfriendly, some unstable--for 22 of 36 strategically critical minerals. Yet the energy resources on federal lands which are owned by the American people could meet our needs for centuries if properly managed. Eighty-five percent of the crude oil yet to be discovered in America is likely to come from public lands, as will 40 percent of the natural gas, 35 percent of the coal, 80 percent of the oil shale, nearly all of the tar sands, and substantial portions of uranium and geothermal energy. Our vast hardrock-mineral wealth includes untapped deposits of essential elements we now import, such as chromium, copper, platinum, and cobalt. The obvious question is, if these abundant resources can help to revitalize our economic strength and to preserve our national security, why aren't we using them to better advantage? To a large extent, the answer can be found in past decisions to restrict public access to the federal estate, thus deferring to us or our successors the tough decisions that flow from Congress' mandate to provide for environmentally responsible development of America's energy and mineral treasures. Here is the legacy this Administration inherited: In January 1981, 7 years after the onset of the Mideast oil embargo: ---Less than 15 percent of federal onshore lands were under lease for oil and gas development; ---No oil and gas leases had been issued in Alaska for 15 years;

Jan 1, 1982

OPEN-HEARTH refractories are not merely an accessory to the furnace. They are the furnace, to all intents and purposes. The steel work of the main structure is merely an open frame which helps to support the refractories ; and the regenerators, a necessary part of the furnace system, consist almost entirely of refractories. Not only do refractories constitute the essential part of the furnace, but they also carry the liquid steel all the way to the point where it begins to solidify. On leaving the furnace the liquid passes through a refractory runner into a refractory-lined ladle, then through a refractory nozzle closed by a refractory stopper on the end of a rod protected by refractory sleeve bricks. The liquid is sometimes sent through an additional refractory- lined tundish, a supplementary ladle, or a refractory runner for bottom pouring, until it finally enters the iron mold in which it solidifies. Even in the mold, refractory materials are sometimes used to provide a nonconducting "hot top." This series, from runner and ladle to hot top, inclusive, is often referred to collectively as the "pouring-pit refractories." REFRACTORY RAW MATERIALS The raw materials available are best classified into basic and acid types. The principal basic raw materials are magnesite, dolomite, and chrome ore. The principal acid materials are silica in various natural forms, and fireclay. Magnesite. Austria was the principal source of magnesite (MgCO3) until recent years, when the Province of Quebec, in Canada, and the states of Nevada and Washington became important sources for the American steel industry. More recently these natural sources have been supplemented by the so-called "sea-water magnesite"-which is the name somewhat incorrectly given to magnesium hydroxide obtained as one of the products

Jan 1, 1964

By T. S. Spicer, C. C. Wright, R. G. Bowman

IN recent years considerable publicity has been given to the problem of atmospheric pollution by fuel-burning equipment. Legislation has been stimulated and smoke ordinances have been enacted, the provisions of which show a definite trend toward stricter control of the emissions not only from the stacks of industrial fuel users but also from the chimneys of domestic consumers. As a result of war conditions, some slackening in the enforcement of these ordinances may be noted, but this is only a temporary expediency caused by the changes necessary in the distribution of the nation's fuel supplies and difficulties in securing the necessary equipment. Previous trends may be expected to continue in the postwar period. Largely because of the consumer demand for automatic heat, but partly because of the legislation against smoke emission, there has been a marked increase in the use of domestic underfeed stokers with the past decade. When correctly adjusted and operated, these units reduce the smoke emission materially, so that even the high-volatile bituminous coals may be burned with little or no emission of objectionable smoke. Unfortunately, however, the use of the domestic underfeed stoker introduces another problem; namely, fly-ash. PRODUCTION OF FLY-ASH The term "fly-ash" is a misnomer, since the fly material is generally a mixture of small carbonaceous particles varying from green coal to coke, and inorganic particles ranging from fluffy ash to small particles of fused clinker. For want of a more comprehensive name, however, the term fly-ash is used throughout this paper to include all the fly material. Even with hand-fired furnaces a certain amount of fly-ash is produced, which necessitates periodic cleaning of the boiler flues or furnace radiator, the smoke pipe, and occasionally the chimney itself. With stoker operations the amount of fly-ash is increased many fold, because of the higher velocity of air travel through the fuel bed. Frequently the amount of this fly-ash attains such proportions as to constitute a definite nuisance to the householder and his neighbors and distracts very materially from the otherwise automatic or semi-automatic performance of the stoker. Virtually all the boilers and hot-air furnaces marketed in the domestic field

Jan 1, 1944

Within the last century, and largely during the latter half of it, the increase of our knowledge of the development of man, both in his search for a livelihood and for power, and in the growth of his reason and conscience, has been greater than all we had known before. The great interest in all kinds of archaeological work and the many excavations made of buried and long forgotten places has put at our disposal historical records not available, and in many cases not known before, and a study of these and other records of human progress from paleontological and geological sources has given us a much broader view of what we call "civilization" than was possible even a short time ago. The old idea that men were created with fully developed minds, speech and reason has yielded to the view that in the upward progress of the human race the development of the mind and reason has been a comparatively recent occurrence, as we think of the half million, and probably more, years that have passed since our earliest records of man were made. The traits that come to us without effort

Jan 1, 1935

By J. D. Lindner, Gene E. Roark

Waterflooding operations in the Langston-Kleiner field. Young County, Tex., are described. Widespread application of formation fracturing has been practiced in both producing and injection wells. Field performance data arc cited which indicate than no detrimental effect on sweep efficiencies and that probable benefits in imectivily have resulted from the fracture treatments. I N T R O D U C I O N This paper is a report on a waterflood operation which is being carried out in the Lanpston-Kleiner field located in Young County, Tex. The oil reservoir aflected by this flood operation occurs in a Strawn sand member at an approximate depth of 3.550 ft subsurl'ace. The operators of' the project are Kleiner Estate. Turncr. Fiske. and West who are hereinafter collectively referred to as the Operators. Although the operation is unusual in several respects, the distinctive feature of this flood has been the widespread application of hydraulic formation fracturing treatments as a means to improve productivity and injectivity of the wells. It shall he the purpose of this paper to present basic information regarding the reservoir characteristics. op- craling practices, and waterflood behavior so that conclusions may be drawn concerning the effects which the fracture treatments have had on the performance of this water flood to datc. DEVELOP MENT Development of the 3,550 ft Strawn sand reservoir occurred during 1951 and 1952. The early development occurred on the Langston and Davis leases which arc in the northern region of the Operators' holdings and the wells were drilled on 20-acre proration units according to the field rules. However, studies of the economics of this program. coupled with the decision to proceed with pressure maintenance by water injection. resulted in the adoption of wider spacing in the later stages of development. This variation in spacing is apparent upon inspection of Fig. I upon which only the 3,550-ft Strawn sand producing and injection wells have been located on the Operators' properties. The development to the north of the operators leases is Ihe Garvey Strawn field and that to the south is the Taylor Strawn field. It wits determined that unitization of the leases to he involved in the waterflood program was not feasihle. Consequently. a system of offset injection wells, or lease line injection wells, was adopted from place to place as required to protect correlative rights in the program. This resulted in a dispersed array of injection and producing wells with relatively close proximity of wells along lease line areas and wider spacing toward

Jan 1, 1956

By Wilson Lundy

THE history of the production of sulfur from salt domes in Louisiana and Texas originated with the operations of the Union Sulphur Co. at Sulphur, La., followed by the Freeport Sulphur Co. at Bryanmound, Tex. Including the present development of Grande Ecaille by the Free-port Sulphur Co., which constitutes the tenth dome to be equipped for the production of sulfur in the Gulf Coast, less than 10 per cent of all the known domes have proved to contain sulfur in commercial quantities. The Grande Ecaille salt dome is in the tidal marsh of the Mississippi River delta in Plaquemines Parish, Louisiana. It is 10 miles southwest of the right descending bank of the river approximately 45 miles below the city of New Orleans and is within 4 miles of the shore line of the Gulf of Mexico.

Jan 1, 1934

By AIME AIME

THE papers on geophysics were roughly divided into two groups*, those presented Monday morning being of a more technical and theoretical nature, whereas the afternoon session was principally taken up with discussions of a predominantly geological flavor. Thus it was made possible for those of a mathematical turn of mind to indulge their penchant for formula and differentials before lunch, leaving the field comparatively free, after lunch, for the geologists to learn of practical applications. The advantage of this classification is evident, and it is to be hoped that in some future meetings it will be possible to hold joint sessions of the geophysicists and mining geologists, to consider the overlap of the two fields.

Jan 1, 1931

By R. W. Raymond

CLARENCE King born January 6,1842, at Newport, R. I. His ancestors on both sides mere New Englanders, of English blood, and among them not a few distinguished themselves in art, science, politics or commerce. His grandfather, Samuel Vernon King (partner in 1803 in the house of Talbot, O1yphant & King, later known as King $ Co.), was a pioneer in the China trade, and four of his sons succeeded him in the business. Three of the four died in the far East; and one of

Jan 1, 1903

By Emery C. Olsen

Most coal mining areas of the Western United States are characterized either by thick beds, steep pitches or heavy cover. Individually, each of these may present inherent safety hazards that influence mining. When all are met at one location, the combined effect is to make the safe operation of the mining property a challenge to management. These combined conditions are met in the coal mines of the Columbia-Geneva Steel Div. of the United States Steel Corp., in southeastern Utah. This coal bed measures up to 16 ft in thickness, the pitch is as much as 25 % and mining is under a cover approaching 3000 ft. The Sunnyside coal bed is found in the Book Cliff Mountains, a great escarpment extending from west of Castle Gate, Utah, some 180 miles to Grand Junction, Colo. West of Green River, Utah, the Book Cliffs swing sharply to the north because of the domelike uplift of the San Rafael Swell to the south- west. It is in this northerly extension of the Book Cliffs that the Sunnyside coal in the Blackhawk Formation of the Mesa Verde Group, Upper Cretaceous Age is found. The strata are transected by numerous faults with from a few inches to as much as a hundred feet of displacement. All of these faults have had some effect on the mining operation, either in roof control or, in the case of major faulting, the pattern of mine development.

Jan 10, 1963

THE compiler, or author, of the Probierbücblein is not known, and the date of its first printing is uncertain. It was obviously not written by an assayer who wished to give a coherent description of his craft for the instruction of others; this was left for Biringuccio first to do. It is easy to believe that originally the Probierbücblein was a random collection from various sources of information useful to an assayer, probably gathered by one of the profession for his own use. It must remain a matter of speculation whether this was shown to a printer, who recognized the opportunity to turn an honest penny and made an inept attempt to give the manuscript the appearance of a coherent account by writing a preface and arranging the various items in somewhat logical sequence, or whether the assayer him- self started this job and was prevented from finishing it. That some sections of the book, especially near the be ginning, present an almost continuous story, while others are chaotic in their arrangement; that several paragraphs are printed more than once in different places; that there are paragraph headings, for which the text was never written, or lost, followed by irrelevant information-all this seems evidence of a job unfinished and points to a publisher's offering for the public's quick money. The demand must have been brisk, for metal working was a profitable profession, and the jeweler who was working with metals but did not care to become completely trained in assay methods would jump at the chance of acquiring easy knowledge. Even the great Agricola has whole sections obviously plagiarized from the Probierbücblein. Neither Biringuccio nor Ercker shows any direct influence, though they and all subsequent metallurgists will in some degree be affected by

Jan 1, 1949

By H. A. Wheeler

It may surprise some of our members to learn, that, among the industries based on the mineral resources of the United . States, clay now ranks third, being exceeded in value of product only by pig-iron and coal. The present annual value of clay-products exceeds the value of the outputs of gold or silver, and also exceeds the combined values of copper, leacl, zinc, aluminum, mercury, antimony and nickel. These facts are shown in Table I. which gives the statistics for the year 1902 :

Jan 1, 1905

By M. W. Strong

THE technique of handling drilling muds varies somewhat, partly because of personal factors but mainly because of differences in forma-tion, the type of problems met with, and the general drilling conditions in different localities. The much greater depths to which bore holes are now carried have made necessary closer attention to and great modifications of all aspects of drilling-mud technique. Increased depth means smaller hole, smaller drill pipe, smaller clearances, higher pumping pressures, higher differen-tial pressures between shows and the mud column, less accurate control of the weight of the mud column, delayed receipt of formation data, and poorer samples. It means longer delays and greater hazards in rectifying mistakes or dealing with accidental occurrences. Equipment on a larger scale is necessary and more pains must be taken with layout. Lastly, the budget costs of raw materials have risen to high figures and economy of time and of direct monetary expenditure have come to mean much more than formerly. A mud laboratory is now part of the essential establishment of a modern oil field and to it current problems can be submitted for the most thorough investigation. The detailed chemical properties of all mate-rials purchased or quarried have to be investigated. Detailed data on the physical properties have to be ascertained and research on improve-ment of material and its most efficient use has to be carried out. In this paper we propose to discuss the main mud problems with which we have to deal in Iran, some of which are peculiar to our local conditions while others are of the general type common to all workers in this subject.

Jan 1, 1938

By Alden Greninger

THAT metallographic structures analogous to the martensite of steel may be found in certain copper-aluminum and copper-tin alloys has been known for many years; similar structures recently were found in certain copper-zinc alloys.1 In all three of these alloy systems the martensite structures result from transformation of the metastable ß phase when the speed of cooling from the ß range is sufficiently high to suppress decomposition into equilibrium phases. ? In the normal decomposition of solid solutions into equilibrium phases, diffusion is needed to bring about the necessary changes in concentration, and the rate of reaction falls almost to zero at temperatures slightly above room temperature. The rates of reaction for martensite processes, however, are not dependent upon temperature; the transformation does not require readjustments of concentration. For example, the marten-site transformation in 60:40 (ß) copper-zinc does not begin until the temperature has dropped to about minus 30° C., and then continues down to minus 130° C. and probably even at lower temperatures.1 Further-more, martensite processes apparently proceed only while the tempera-ture is falling, within the proper range, and cease completely while the temperature is held constant; ? and they cannot be suppressed by extremely rapid cooling although the rate of cooling for some alloys may be increased to over 10,000 times the critical cooling velocity. Isaitschew, Kaminsky and Kurdjumow2 account for these observed behaviors of martensite processes by postulating that the mechanism " . . . consists in a regular rearrangement of the lattice in such a way

Jan 1, 1939

By David R. Maneval, W. E. Foreman, J. Richard Lucas

INTRODUCTION The objective of this chapter is to inform the industry, as well as the public, of the challenges in dealing with problems associated with air and water contamination by coal preparation plants. The need for an informed industry is most important. It is hoped that some contribution may be given to a more efficient and economical approach to the problems of plant waste contaminants at individual plants. The problem has many facets, and consideration should be given to specific areas before any significant problems develop at a given plant. It is then possible to have a reasoned approach before the pressures of an emergency environment force hasty and incomplete solutions. It will be necessary to anticipate these problems in the design of new preparation plants, and advance consideration should be given to all problems concerned with contaminants.

Jan 1, 1979

By G. Ostberg

OXYGEN has frequently been considered responsible for phenomena in the metallurgy of cast iron which are not sufficiently explained by the presence of other elements. Oxygen and oxides have been regarded as critical factors, particularly for the solidification process, and specifically in the formation of graphite. However, the evidence for an influence of oxygen has mostly only been indirect or qualitative. Furthermore, quantitative data on the oxygen content of cast iron presented in the literature have often been less conclusive as being apparently determined with insufficient regard for the difficulties associated with the sampling and analysis. These problems, experimental and theoretical, have been studied in this investigation. An attempt is made to bring the views on the soluble amount of oxygen in cast iron on a level with the present understanding of the thermodynamics of these types of alloys. Although there are no experimental data on the complete multicomponent cast-iron alloys some conclusions have been drawn from investigations on simpler systems. The order of magnitude of the solubility of oxygen in cast iron is considered in the first part of the paper. The second part deals with the oxygen content actually present under practical conditions. First the possible sources of errors in sampling and analyzing methods are examined. Finally some observations on the oxygen and oxide content of malleable iron during the production process are made. THERMODYNAMICS OF OXYGEN SOLUBILITY When cast iron is saturated with oxygen the saturation phase is essentially carbon monoxide or silicon dioxide depending upon the composition of the iron, the temperature, and the rates of formation of the oxides.* The latter occurs accordiw to the O + C = CO, Kc0 - a COa J 20 + Si = SiO2, Activities are used here instead of weight pct concentrations, since activities are believed to show more sensitively the effects of the interaction of all the alloying elements. Calculations involving activities are, however, seriously hampered by lack of experimental data on the interactions between the components encountered in the multi component cast-iron system Fe-O-C-Si-Mn-P-S- and so on. In order to make an estimate of the oxygen solubility reason-

Jan 1, 1959

By William M. Brewer

Since writing the paper on this subject,* which was presented at the Atlanta meeting in October, 1895, I have had opportunity for more thorough investigations in several localities, and venture, therefore, to offer some additional facts and opinions. The literature of the subject is not very abundant. Dr. George F. Becker's " Reconnaissance of the Gold-Fields of the Southern Appalachians "† contains some brief notes relating to Georgia, but does not include Alabama. The paper of Messrs. Nitze and Wilkens on " Gold-Mining in the Southern Appala-

Jan 1, 1897