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By J. F. Kemp

The death, on the 30th of May, 1896, at Paris, of the venerable Gabriel Auguste Daubrée, an honorary member of the Institute, recalls with emphasis the great value of his varied contributions to geology, mineralogy and hydrology. In fact, more and more as the years pass, and as attention is given to the obscure problems of metamorphism, of the development of joints, of slaty cleavage, of schistosity, of fault-systems, of the subterranean circulations of water, and of many other agencies which are often closely involved in the production of ore-bodies, the appreciation of his work increases, and quotations from his papers are made. Daubrde was born June 25, 1814, at Metz. After receiving

Jan 1, 1897

By Francis L. Bosqui

The following paper embodies a report which I made on the filter-press treatment of slimes at the Liberty Bell mine, Telluride, Colo. At the time this report was submitted, the management deemed it wiser to defer the installation of so costly a plant as the one required, in the hope that some of the many investigators in the field might soon evolve a cheaper and more perfect method of slimes-treatment, and one better suited to the conditions at Telluride. The Liberty Bell ore consists essentially of quartz and clay, with iron pyrites disseminated through the quartz in very fine particles. There is considerable iron and manganese stain in some of the ore, the latter especially in the clays, which are sometimes quite black. Occasionally particles of galena, zincblende, gray copper and a few other minerals are seen, but they are comparatively rare, and not in sufficient quantity to affect considerations of treatment. Free gold is occasionally seen in the quartz, and one or two instances of mire silver have been observed. The milling-plant consists of an 80-stamp amalgamating mill which crushes through 20-mesh screens; 20 Wilfley concentrating tables, taking out, in iron sulphides, about 2 per cent. of the total ore crushed; and a cyanide plant consisting of two tiers of 33 ft. vats, five in each tier, fed by revolving pipe-die tributers. The slimes overflow from the upper settling tanks through gates with adjustable outlets, and thence to a large canvas-plant, which efects only a small saving. This slimes product, of which about 100 tons escape per day (or 38 per cent. of the total ore crushed), contains about 3 per cent. of dry solids. Of this approximately 93 per cent. will pass a 200-mesh screen. The slimes range in value between $3.90 and $4.87 per ton, the values being about equally distributed between gold and silver. The actual averages for ore and slimes during the years 1900-

Jan 1, 1904

By K. P. Gupta

The Cb-rich boundary of the (Cb,Al) a phase field at 1250OC is near 41 pct Al. The Al atoms tend to occupy the C. N. 12 sites in this structure. A homologous (Ta,Al)a phase was identified. No a phase was found in the Mo-Al system at 1200°C. The first binary o-phase with a non-transition element as a major component was found1,2 in the Cb-Al system. The composition of this phase was reported2 as approximately 34 at. pct Al, based on X-ray diffraction patterns taken of alloys in the as-cast condition. Further study of the composition of this o-phase, therefore, appeared desirable. Since Si was previously found3,4 to occupy preferentially the lowest C.N. sites (I and IV) in the a phase, and preliminary resultsa indicated that Al may show similar ordering, one of the aims of the present work was to obtain more complete information on ordering in (Cb, Al) o. Among the binary systems of Al with Ti-, V-, and Cr-group elements, the Ti-Al, Zr-Al, V-Al, and Cr-Al systems are known to comprise no o-phase. In the present work a Ta-Al and a Mo-Al alloy were studied in an effort to find additional o phases with Al as a major component. EXPERIMENTAL PROCEDURES AND RESULTS An alloy with the intended composition of Ta + 40 at. pct Al was prepared by arc melting in He atmosphere. In both the as-cast condition and after annealing for 10 days at 1250°C and quenching in cold water this alloy consisted of two phases, as seen in the X-ray pattern and the microstructure. One of these phases was identified as the o-phase; the observed and calculated d-spacings are shown in Table I. The lattice parameters of this o-phase are a = 9.972 A, c = 5.214 A and c/a =0.5228, as determined from a Debye-Scherrer pattern using Fe K a radiation. The d-spacings for the unknown second phase are given in Table 11. The alloy contained approximately 25 pct of the unknown phase after annealing, as estimated on the basis of microscopic examination. A Mo-Al alloy was prepared by arc melting, with an intended Al-content of 35 at. pct. The alloy button was annealed for 7 days at 1200°C and water quenched. The X-ray pattern of the alloy in both the as-cast and the annealed state showed the reflections of Mo3Al (Cr30 type structure) and an unknown phase different from a. Six Cb-Al alloys were prepared in the composition range 30 to 50 pct Al. All alloys were arc melted in He atmosphere. After annealing for three days at 1175oC in evacuated silica capsules and quenching in water, the alloys with 30 to 40 pct Al contained three phases, namely the o-phase, Cb3Al (Cr3O-type structure) and an unknown phase. The alloys with more than 40 pct Al contained two phases, namely, what appeared metallographically, the o-phase and the same unknown phase. In the alloys containing less that 38 pct Al, the unknown phase was not present after annealing for 4 days at 1250°c,

Jan 1, 1962

By Howard N. Eavenson

In many of the bituminous-coal districts of this country, more than one seam of workable coal exists, and in most cases the lower seam is the more attractive, owing to either its greater thickness or its superior quality. Apprehension that the mining of a seam will destroy the availability of all overlying seams has hindered the development of many fields and has led to the unprofitable working of certain seams in order to save them from an expected total loss. The U. S. Coal & Coke Co., Gary, W. Va., was the first operator in the Pocahontas field to mine the No. 4 seam extensively, which occurs about 80 ft. above No. 3, the scam that was worked first. This was due to the fact that over large areas the upper seam was the only one of workable thickness, at that time. In two places, both seams were workable in the same area, the No. 4 being thinner and containing more impurities than No. 3 seam. In mining these areas, an attempt was made to keep the workings in the upper seam in advance of those in the lower one, and no pillar robbing was done in No. 3 seam until after pillars in that part of the upper seam directly over it had been mined. This resulted in an excessive development in the lower seam, with large areas of finished rooms and standing pillars. The top fell badly, and after a couple of years the falls became so heavy that pillar drawing was unduly expensive. To overcome this obstacle and allow No. 3 seam to be worked in some territory where No. 4 was thick, but too dirty for present use, a study was made of operating methods applied to superimposed seams in Pennsylvania and Maryland. This was started more than seven yean ago by the writer; his data, supplemented by more recent information gathered by his associates, and by two cases mentioned in recent foreign publications, form the basis of this paper. Central Pennsylvania In central Pennsylvania, the lower coal measures contain several seams of nearly the same thickness but of varying quality, and as mining

Jan 1, 1923

By Howard N. Eavenson

In many of the bituminous-coal districts of this country, more than one seam of workable coal exists, and in most cases the lower seam is the more attractive, owing to either its greater thickness or its superior quality. Apprehension that the mining of a seam will destroy the availability of all overlying seams has hindered the development of many fields and has led to the unprofitable working of certain seams in order to save them from an expected total loss. The U. S. Coal & Coke Co., Gary, W. Va., was the first operator in the Pocahontas field to mine the No. 4 seam extensively, which occurs about 80 ft. above No. 3, the scam that was worked first. This was due to the fact that over large areas the upper seam was the only one of workable thickness, at that time. In two places, both seams were workable in the same area, the No. 4 being thinner and containing more impurities than No. 3 seam. In mining these areas, an attempt was made to keep the workings in the upper seam in advance of those in the lower one, and no pillar robbing was done in No. 3 seam until after pillars in that part of the upper seam directly over it had been mined. This resulted in an excessive development in the lower seam, with large areas of finished rooms and standing pillars. The top fell badly, and after a couple of years the falls became so heavy that pillar drawing was unduly expensive. To overcome this obstacle and allow No. 3 seam to be worked in some territory where No. 4 was thick, but too dirty for present use, a study was made of operating methods applied to superimposed seams in Pennsylvania and Maryland. This was started more than seven yean ago by the writer; his data, supplemented by more recent information gathered by his associates, and by two cases mentioned in recent foreign publications, form the basis of this paper. Central Pennsylvania In central Pennsylvania, the lower coal measures contain several seams of nearly the same thickness but of varying quality, and as mining

Jan 1, 1923

By Samuel L. Hoyt

The present report represents that part of the work that has been done by the War Minerals Investigation, Manganese Section, of the Bureau of Mines, on the use of manganese alloys in open-hearth practice. The magnitude of the work and the number of people participating in one way or another make it difficult to acknowledge adequately the services of all who have contributed to the success of the work. It would be amiss, however, to pass to the body of the report without mentioning the hearty cooperation and willingness to assist of the various manufacturing interests. With such a sympathetic attitude toward this investigation, our work was assured of success. Inasmuch as the unhappy circumstances that rendered this investigation necessary have now passed, this report is made in the hope that the results may prove of some permanent value to the peace-time operation of our open-hearth industry. Broadly speaking, the purpose of the manganese investigation was to consider the most suitable means of utilizing our domestic supply of manganese and thus relieve, to the maximum extent possible, our shipping of the burden of importing manganese ores. It was not held that any decided shortage of manganese was imminent but rather that every legitimate means should be utilized for making our ship tonnage available to European service. While we have considerable metallic manganese in this country, it occurs largely as a low-grade mixture with iron or silica or with both. The open-hearth investigations, therefore, were carried on to determine the extent to which domestic or low-grade alloys could properly be substituted for high-grade alloys without materially impairing the steel production as to either quality or quantity. Also, it was held that such an investigation would yield valuable results to the steel industry as well as contribute, in no small way, toward directing future investigations in the same field. To the practical steel manufacturer, especially to him who felt no immediate concern about

Jan 1, 1920

By F. W. Glaser, W. Ivanick

A pressure-sintering method was used to produce binder-free and very dense TiC specimens. Some physical properties of these TIC bodies were determined and found to compare favorably with those of certain cemented Tic grades. It was also observed that the hot transverse rupture strength of TiC bodies remained substantially the same regardless of the amount or type of binder material used. STUDIES of the structure and physical properties of refractory materials have been intensified recently because of the urgent need for nonstrategic materials that retain their strength at high temperatures. Research aimed at determining and improving the physical properties of cemented carbides and borides has been accelerated with a view toward possible use of such materials in connection with turbine blades, rocket nozzles, and other high temperature applications. On the hypothesis that the strength requirements in connection with some of the above applications could be met only by proper choice of cementing agents for such refractory materials, the literature describing the physical properties of borides or carbides was reviewed. However, with a few exceptions,'-" references were found only to compositions containing at least one or more auxiliary binder metals. Cobalt and nickel are among the most frequently employed cementing agents. The melting point of Tic (approximately 3250°C) and therefore the sintering temperature, at which notable densification of a cold pressed Tic powder compact could be expected in the absence of a liquid binder phase, is relatively high. The present study makes use of a high temperature, pressure-sintering procedure, recently described by one of the authors in connection with the sintering of binder-free ZrB,," to produce dense bodies of sintered Tic—free of any cementing agent. During the course of this sintering study, some physical properties of dense Tic bodies produced by this method will be discussed. Materials, Preparation of Samples, Testing Methods The procedure for the forming of Tic powder consisted of mixing graphite and TiH, powders in stoi-chiometric proportions, and heating this mixture in a H, atmosphere and carbon crucible by high frequency, to temperatures ranging between 1900° and 2100°C (3452" and 3812°F). The powdered carbide was then comminuted and screened to the desired particle size. Table I shows the chemical analysis of the two grades that were employed for the production of samples during this work. Bodies of Tic, approximately 2.5xlx0.5 cm were produced in graphite molds that were heated by direct conduction. Sintering was carried out at temperatures for time intervals ranging from approximately 0 to 30 sec under a constant pressure of about 1.3 tons per sq in. An alternate method for the production of samples consisted in cold pressing the individual Tic grades at pressures ranging from 4 to 10 tons per sq in. and sintering in a hydrogen atmosphere in graphite crucibles heated by high frequency induction. Sintering temperatures ranged from 2600° to 2900°C (4715° to 5255°F). Electrical testing was done by measuring potentiometrically the voltage drop over a length of 1.5 cm for a current of 10 amp at room temperature. Cross-sectional areas as well as densi-

Jan 1, 1953

By D. L. Harris, A. M. Gaudin

THE following results, presented here in condensed form,1 were obtained in a preliminary study of the adsorption of n-hexane thiol, hexyl mercaptan, on sphalerite, zincite, willemite, and quartz, from aqueous solution and from a gas. Interest in this subject was aroused by a Belgian report2 of effective use of hexyl mercaptan for flotation collection of oxidized zinc minerals. The relatively low boiling point, 149°C, of the mercaptan3 suggested the desirability of extending the usual measurements of partition of collector between aqueous solution and gas and between gas and mineral. It is believed that this paper presents the first measurements of this type on a flotation system. Attempts were made to carry out the measurements at equilibrium, but as the work progressed it became increasingly doubtful that this desirable condition had been achieved. To control composition and extent of the gas phase, the apparatus was a wholly-enclosed thermally-controlled glass system. Because of these constraints and the desirability of dealing with pure minerals, a scale of operations was chosen in which a few grams of deslimed mineral were used in each test. It was also necessary to choose a particularly sensitive method for mercaptan analysis, and in fact a method that would permit the experimenters to follow the approach to equilibrium. For these reasons mercaptan marked by radiosulphur 35 was used. An analysis was made for the radiosulphur by a modification of the method of Gaudin and Carr.4

Jan 9, 1954

By Ben L. Seegmiller

Localized open pit slope failure was avoided as an apparent result of a practical rock mechanics program conducted at the Twin Buttes copper operation. The key to the program was the application of cable bolting, a technique that artificially supports open pit slopes using properly installed post-tensioned cables. As a result of the research and testing program, extensions of the cable bolting principal became significantly apparent. • The economics of artificial stabilization appear to be overwhelmingly favorable, and • Best practical applications are "final" pit slopes, slopes beneath permanent structures and potentially slope failing areas. Success of this research is manifested by the fact that similar stabilization systems are presently under consideration for Twin Buttes as well as other open pit operations.

Jan 12, 1974

R. M. Raymond, New York, N. Y.—The filling and drawing down of the overhead material was done at considerable depth, which is not the usual method in which it starts at the surface.. R. J. Mechin.— It is a little more than 1000 ft. at El Bordo. The vein above had been caved practically to the surface and some of the ore had been excavated, using underhand and overhand square-set methods. This was far enough away from the shaft to prevent any bad effects. When the sill floor was taken out, to insure the old cave material following down well, we put chutes in the square sets for several weeks until we were sure that the material from above was moving down; on each level above, several crosscuts were driven into the old fill by which we could see the material coming down and thus be sure it was following the first. We had to dynamite it very little because it was dry and dusty. The only trouble was that timber starting from the old square sets would get across the chute and hang up. R.. M. Raymond.—HOW many floors did you operate at once? R.. J. Mechin.—We would operate one floor through the whole length and prepare for the second. F. W. SperR, Houghton, Mich.—Could you have worked it in steps? R.. J. Mechin.—Yes; but working it all on one floor was much better for ventilation. The passage between steps would tend to become heavy and blocked and, as the passages from the mining floor down are usually filled with ore, there would be no way for the air to pass up. By means of doors and fans, air was driven to the extreme end of the orebody through the stope and up the other end; but it could have been worked in steps. F. W. SpeRR.—D the following-up material ever become so heavy that you could see weight on the caps before you had to take out the posts?

Jan 1, 1927

By E. P. Barrett

THE high-frequency laboratory induction furnace with a rotating liquid crucible enables research workers to conduct certain investigations heretofore very difficult or impossible to realize because vessels are not obtainable that are capable of resisting the physical conditions or the chemical actions to which they are subjected. Applications for patents covering commercial uses of centrifugal liquid crucibles were filed in the United States in 1919,1 in France in 1925, in the United States and Germany in 1926,2 and in France in 1927.3 In 1928, Schuette and Maier,4 of the Bureau of Mines, reported the construction of a whirling table beneath a high-frequency induction furnace. SHAPE AND SIZE OF CENTRIFUGAL LIQUID CRUCIBLES When a vessel containing a liquid is rotated, the inner surface of the liquid takes the shape f a paraboloid under the simultaneous action of centrifugal force and gravity. The internal dimensions of the paraboloid rotating liquid crucible are governed by the diameter of the container and its speed of rotation. Melted Wood's metal was poured into cylinders 2 ½ in. in diameter, which were rotated at 180, 300, and 468 r.p.m. When the metal was solid, a slurry of plaster of Paris was added, and rotation continued until the plaster had set. Fig. 1, a photograph of sections f the cylinders, shows the effect f speed f rotation of the containers upon the shape f the inner surface f the rotating liquid crucibles.

Jan 1, 1938

By G. Broughton

For the past few years a great amount of work has been done on the viscosity characteristics and gelation of clay suspensions, much of which has been reported in papers published by the Institute.7,12,18,19,24 Impor-tant reviews have been made elsewhere by Evans and Reid,10 Marshall20 and Clews, Macey and Rigby,8 the last two on the general properties of clay. It is unnecessary, therefore, to recapitulate past work beyond recalling that three explanations for the high viscosity and gelation of clay suspensions have been put forward. For lack of more exact nomencla-ture, these may be called the water hull,16 mechanical interference" and attraction-repulsion" theories. The first pictures the clay particles as surrounded by relatively rigid water envelopes, which increase effective volume; the second emphasizes the mechanical interference of platy particles or their agglomerates; while in the third the particles are assumed to be held relatively rigidly at a distance from each other determined by the balance between the attractive (van der Waal's) forces and the elec-trical repulsions of the charges. 13,14 This article presents fresh data on clay suspensions, particularly on the influence of previous flow history of the suspensions, specific contra-ions, temperature, solvation and particle size, in an attempt to contribute to the solution of the problem.

Jan 1, 1938

By V. Runolinna, R. T. Hukki

Preliminary separation of precious metals by flotation can offer a simplification of the conventional method of treatment of anode slimes. Laboratory flotation experiments show that rich gold and silver concentrate can be obtained with excellent recoveries. THE purpose of this paper is to present the results of an investigation into the possibilities of separating precious metals from anode slimes by selective flotation. The work was carried out at the State Research Institute in Helsinki, Finland. The sample of anode slimes tested was submitted by the Outo-kumpu Co. in Finland. In 1947 the average assay of filtered and dried anode slimes in the Outokumpu refinery in Pori was as follows: Au, 0.50 pct; Ag, 9.38 pct; Cu, 11.02 pct; Ni, 45.21 pct; Pb, 2.62 pct; Fe, 0.60 pct; Sn, 1.00 pct; Sb, 0.04 pct; As, 0.70 pct; Se, 4.33 pct; S, 2.32 pct; SO,, 2.17 pct; SiO2, 2.25 pct. The daily assay naturally varies considerably from the figures presented above. The present conventional method of treatment of anode slimes consists of the steps shown in the flowsheet in fig. 1. As seen from this simplified flowsheet, the present method of treatment involves many steps by which the components of the anode slimes are removed one after another until the main products, gold and silver, may be separated. Due to the small scale of operations, the above procedure is carried out in small batches requiring considerable amount of manual labor. If, however, the anode slimes could be treated in

Jan 1, 1951

By V. Runolinna, R. T. Hukki

Preliminary separation of precious metals by flotation can offer a simplification of the conventional method of treatment of anode slimes. Laboratory flotation experiments show that rich gold and silver concentrate can be obtained with excellent recoveries. THE purpose of this paper is to present the results of an investigation into the possibilities of separating precious metals from anode slimes by selective flotation. The work was carried out at the State Research Institute in Helsinki, Finland. The sample of anode slimes tested was submitted by the Outo-kumpu Co. in Finland. In 1947 the average assay of filtered and dried anode slimes in the Outokumpu refinery in Pori was as follows: Au, 0.50 pct; Ag, 9.38 pct; Cu, 11.02 pct; Ni, 45.21 pct; Pb, 2.62 pct; Fe, 0.60 pct; Sn, 1.00 pct; Sb, 0.04 pct; As, 0.70 pct; Se, 4.33 pct; S, 2.32 pct; SO,, 2.17 pct; SiO2, 2.25 pct. The daily assay naturally varies considerably from the figures presented above. The present conventional method of treatment of anode slimes consists of the steps shown in the flowsheet in fig. 1. As seen from this simplified flowsheet, the present method of treatment involves many steps by which the components of the anode slimes are removed one after another until the main products, gold and silver, may be separated. Due to the small scale of operations, the above procedure is carried out in small batches requiring considerable amount of manual labor. If, however, the anode slimes could be treated in

Jan 1, 1951

By D. E. Hilts, R. P. Miller

A large coal-fired power plant is to be built jointly by Pacific Power & Light Co. of Portland, Ore., and by The Washington Water Power Co. of Spokane, Wash., at a site about six miles northeast of Centralia, Wash. (Fig. 1 inset). Coal will be mined from nearby open-pit strip mines that will require cut slopes up to 250 ft in height. Coal will be removed from a seam approximately 50 ft thick, located at the bottom of the mine slopes. The coal fields are located in a geologically complex area that has been subjected to intense folding and faulting. As a result, the soils and rock comprising the overburden are highly fractured, jointed, and faulted. Classical approaches to slope stability based solely on the physical proper- ties of the overburden appeared to offer little assurance that theoretically stable slopes would remain stable. Further, the scope of the exploration program that would be required to provide a reasonable evaluation of the primary and secondary structural features from which a statistical evaluation could be developed was considered impractical. As part of the development of an overall mining plan, an experimental Pilot mine excavation, about 225 ft high and about 400 ft long at the base, was made within the coal field. This experimental cut was to provide firsthand knowledge of cut slope behavior. Our purpose at the Pilot mine was to observe the cut slopes as the excavation proceeded. To accomplish this purpose, the highwall of the experimental cut was instrumented to measure face movements and movement at depth behind the face. In addition, a detailed geologic map of the soil and rock conditions exposed in the highwall was prepared, and continual visual observations of the mine were made, noting significant events as they occurred.

Jan 1, 1970

By Harry V. Warren

During the past few years the author has had an opportunity to examine a number of base-metal mines in the western United States, France and Spain. Nearly all of these mines produced some silver, and laboratory studies of the relationship between the silver and the various base-metal minerals in the ore have given some interesting and, it is to be hoped, enlightening facts. As this work was undertaken primarily to ascertain the amount of silver chemically associated with, not controlled by, the various base-metal minerals, the laborious and not always satisfactory method of picking out "pure" samples of each mineral from many localities was employed. However, the results obtained have justified the time that has been spent. Not only have the conclusions arrived at in different mining areas been in accordance with one another but in many instances they have afforded scientific support or explanations for much of the knowledge that operators in the various camps have acquired by practical experience. Although many of the conclusions are not new, many of the facts are, and the results, if they do nothing else, serve to confirm the findings of some of the other workers in this field, particularly the work of Nissen and Hoyt1 and of F. N. Guild2. Dr. S. G. Lasky3 has suggested a novel method for determining from a series of algebraic equations the amount of silver controlled by each of the base-metal minerals but I doubt very much whether his method can be justified, chiefly because there appear to be more variables to be considered than the few that appear in his equations. Typical Examples of Irregular Silver Distribution Combination Mine, New Mexico, U.S.A.—In this mine an examination of the assay plans either of the mine or of the average mill feed or products

Jan 1, 1935

By Stefan S. Kapusniak, Nichol Riggott, Stephen F. Smith

Stability investigations have been carried out in a number of major coal mining tunnels in the U.K. using various instrumentatcon techniques. The paper describes these instrumentation methods and presents results from studies in several tunnels. Both long and short term stability aspects are discussed. Prediction of tunnel stability is examined in relation to tunnel support requirements. Computer simulation techniques are used along with actual underground measurements to identify tunnel design parameters for influencing choice of support and prediction of long term stability.

Jan 1, 1984

"Copper was first made in Butte by the use of iron for its precipitation from mine water in 1890. In consequence of a fire breaking out in the St. Lawrence mine of the Anaconda Copper Mining Company in November, 1889, a large quantity of water was poured into the workings, with the intention of flooding the mine and extinguishing the fire. This proved to be impracticable, but this water, on being pumped to the surface, was found to be high in copper sulphate,—tradition says 75/100 of 1 per cent. The Anaconda Copper Mining Company gave Wm. Ledford a lease on this water. He first (lug holes into the ground, filled them with scrap iron and allowed the water to flow through them. Later he built an open-top flume which he partially filled with iron and passed the water through the by the iron precipitation method. An assay in- the year 1890 from Gagnon mine water, showed .0016 per cent or 28 lbs. copper per day. The mine was then opened to the 1,000 level.None of the mine waters encountered in the solid rock in the mines of Butte contained copper in sufficient quantity to produce the metal profitably by the iron precipitation method. An assay in the year 1890 from Gagnon mine water, showed .0016 per cent or 28 lbs. copper per day. The mine was then opened to the 1,000 level."

Jan 1, 1913

By Lyon F. Terry

INCREASING domestic demand for products, a sharp reduction in exports to Europe, and a rise in imports from South America were the chief features of the economic side of the industry in 1940. As the war progressed it became evident that exports to former European customers were being cut off or drastically reduced, leaving heavy inventories of products in the hands of many American refiners who had anticipated larger demands from the belligerents. Stocks of motor fuel reached burden-some proportions early in the year for the added reason that refining operations were stimulated by heavy demand for heating oils. Excessive tanker rates for Gulf to Eastern Seaboard movements during the first part of 1940 contributed to the accumulation of products on the Gulf Coast, where refinery gasoline prices were forced to extremely low levels by midyear. Tanker rates receded to normal during the summer but have since risen again to the approximate equivalent of pipe-line tariffs from the Mid-Continent.

Jan 1, 1941

By Leo Dana

INTRODUCTION THE object of this paper is to discuss the factors and conditions that affect the observed values of the melting points of refractory materials and to describe practical methods for the determination of these points. While it appeared to be necessary to discuss some of the general properties of silicates and refractories, these subjects have been entered into only in so far as they relate to the melting point and its determination. Refractory materials such as fireclays, firebricks, and minerals generally, may be considered to be composed of compounds of metallic oxides, solid solutions of the oxides, the pure oxides, or mixtures of the three classes together with small amounts of a variety of chemical compounds. The oxides of silica and alumina occur most commonly in refractory materials; in combination with. these, oxides of the alkali earth, the alkali, the iron group, and the rare earth metals are frequently found.

Jan 9, 1919