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By John Fulton

THE increase in the production of iron has been accompanied by a growing demand for an improved quality, and more especially at the present time, in the manufacture of Bessemer steel, which is rapidly becoming an important branch of industry. This has led the makers of pig iron to a careful investigation of the composition of the materials from which their metal is produced, the inquiry being greatly assisted by a cordial alliance of science and practice. Formerly, chemical science was held in abeyance, or admitted in a hesitating experimental way ; but now it is received as a valuable auxiliary, and its decisions are accepted as final and conclusive. It is called on to assist the iron-maker in determining the quality of his stock, and to detect the presence of injurious elements in his fuel, ores, flux, or iron. The object of this paper is to submit the method now in use at the furnaces of the Kemble Coal and Iron Company in the Broad Top coal and iron region, for removing, by a process of crushing and washing, slate and other impurities from coal, designed, when coked, for furnace fuel. It is not contemplated to claim very advanced progress in this work, believing that it is susceptible of improvement, but to show that some progress has been made in a comparatively new field, and it is hoped in the right direction, since coke is probably destined to become the principal fuel in the metallurgy of iron. The Broad Top coal region occupies an isolated geographical position, standing 25 miles east from the Alleghany field. It is associated with the latter by the structure of its coal, and more closely with the Cumberland field by a similarity in the quality of coal.

Jan 1, 1875

By Charles S. Barrett, Robert F. Mehl

It is generally understood by workers in the field of the crystal structure of metallic alloys that terminal solid solutions are of two types, the substitutional and the interstitial. In reviewing the literature, the work of Weissl on the crystal structure of the alpha copper-tin alloys was encountered, in which a new type of terminal solid solution was proposed. In brief, Weiss' findings showed that the density of the alloys calculated from the side of the unit face-centered cube on the assumption of simple substitution—that is, with four atoms to the unit face-centered cell—was much higher than the density measured directly. It was suggested that the assumption of four atoms to the unit cube is not valid for these alloys, and that each unit cube contained less than four atoms; in other words, that one tin atom replaces more than one copper atom, leaving some atomic positions unoccupied. Such a structure, if verified, would have far-reaching significance in the study of the crystal structure of metallic alloys. It would indicate a complexity in terminal solid solutions not hitherto suspected and might encourage work leading to the discovery of other alloys of the same type, and perhaps to types intermediate between it and the two recognized types. It is of importance, therefore, to reinvestigate these alloys with respect to the type of solid-solution structure obtaining therein. Materials and Experimental Method The alloys were prepared from electrolytic copper cut directly from the cathode and the high-purity tin furnished by the U. S. Bureau of Standards for the calibration of thermocouples. No analyses for impurities of these materials or of the finished alloys were made, since such impurities as might be present could have only a wholly inappreciable effect upon the data obtained and the conclusions drawn. The alloys were made by melting the weighed copper charge in a graphite crucible under a KCl-LiC1 flux with later additions of NaC1, using induction heating. When the copper was melted the weighed portions of tin were

Jan 1, 1930

By Heinrich Ries

In another place,* the writer has called attention to the modern methods of the laboratory investigation of clay, and it is desired here simply to discuss one branch of the subject, which, though of considerable importance, has heretofore received little attention in this country, viz., the rational analysis of clay. In order, however, the better to point out the bearings and advantages of this procedure, it is necessary to refer briefly to the ultimate analysis as well. The remarks in this paper refer only to the use of clay for the manufacture of clay-products. Pure clay or kaolin-f is extremely refractory, possesses little plasticity, and usually shrinks aud warps considerably in burning. Even the smallest proportion of impurities changes these properties, so that the kaolin exhibits variations in shrinkage, plasticity, tensile strength, fusibility, and often color when burned. The majority of nearly pure kaolins consist of kaolinite (A1,O2 2SiO,, 2H20), undecomposed feldspar, and quartz. The kaolinite generally forms the finest particles of the clay and is known as the clay-substance, while the rest of the clay-particles are collectively spoken of as sand. In the ordinary or ultimate analysis, the substances generally determined are silica, alumina, ferric oxide, lime, magnesia, alkalies and water. An analysis of this type simply regards the clay as a mixture of elements or oxides, but gives no clue as to the actual condition in which these substances exist, i.e., whether as silicates, oxides or carbonates, etc., a point which it is of the highest importance to know; for the individual components of the clay influence its properties not only according

Jan 1, 1899

By William Metcalf

ONE of the first questions that naturally occurs to one who handles steel is," Why does steel harden ?" To answer this question the chemist and physicist have devoted much thought and experiment, and while they have enriched our store of knowledge of the nature and composition of steel, it cannot be said that they have yet solved the problem involved in its hardening. In this communication I desire to direct attention to a line of investigation yet new, in the hope that it may receive the attention of those who have the time and ability to pursue it. I refer to magnetism. There are so many parallels between the action of magnetism on iron and steel and their behavior under different processes of manipulation that it would seem as if there must be some connection between the forces at work in the different cases, if, indeed, there be not an identity of force in all of these cases. Magnetism, as we know it, may be merely the visible manifestation of forces, which may serve as a guide to lead us to an exact knowledge of the structure, the strains, and the resistances with which we have to deal in iron and steel. If a magnet be brought close to a pile of iron filings, the little pieces of iron will fly to the magnet and attach themselves to it, with their longer axes lying in the direction of the force. If molten cast iron be poured into an iron mould,-a chill,-the iron upon crystallizing will form needlelike crystals, with their long axes normal to the surfaces of the mould. If the iron is at the proper temperature and the quantity small, compared to the mass of the mould, the whole of it will be chilled, or set, in' the hard needlelike crystals

Jan 1, 1881

By S. Skowronski

The melting of cathode copper, ususally containing 95.98+ per cent. • Cu, would appear to be a simple matter. Owing to the well known affinity of copper for sulfur, however, so much sulfur is absorbed by the copper during the operation that a long and expensive refining process is required to remove it, and the final product is inferior in purity and lower in electrical conductivity than the original cathode copper. The furnace operation, as now conducted, includes the following stages: 1. Charging the cathodes into the furnace. 2. Melting the cathodes. 3. Oxidizing period—saturating the copper with cuprous sub-oxide and bringing the metal to the condition known as "set copper;'' this is now done by blowing air into the molten bath of metal. 4. Reduction period, otherwise known as "poling," whereby the oxygen previously added is removed by covering the molten bath completely with coke or charcoal and introducing large poles of green wood; this reduces the cuprous sub-oxide, bringing the copper to the "tough pitch" stage ready for casting. 5. Casting Period. Many experiments have been made to obviate the long periods of oxidation and subsequent reduction, with no success. While the copper first cast will be good, as indicated by the set surface of the bars, it is impossible to hold it to the "tough pitch" condition, and long before the whole charge has been poured the copper will become "overpoled," entailing numerous difficulties. Sulfur has always been blamed by the furnace men as the reason why this refining process is necessary, yet the literature on the subject does not sufficiently emphasize how small a proportion of sulfur will ruin copper for practical purposes. The sulfur absorbed by copper during the melting period comes from two sources: (1) the sulfate left on the cathode sheets in the tank houses; (2) the fuel. The percentage of sulfates on the cathodes is variable, and depends on the care taken in washing the cathodes after removing

Jan 1, 1919

By E. S. Bardwell

Each of the three refining furnaces in use at Great Falls is provided with a waste-heat boiler. The general arrangement of furnace and boiler is as shown in Fig. 1. Two of the furnaces have hearths 45 ft. 7 in. by 14 ft. 6 in.; the third has a hearth 46 ft. 101/2 in. long and of the same width as the other two. The furnaces at present are equipped for firing with natural gas. As originally constructed two of the furnaces had hearths 36 by 14 ft., and were designed to use coal on grates, but these furnaces were lengthened and fired successively with pulverized coal and oil. The third furnace was added in 1926 and was oil-fired until 1928. Since that year natural gas has been in use on all of the furnaces. The changes that have occurred in connection with furnace design and the comparative performance of the furnaces with various fuels were described1 by the author in 1932. Two of the furnaces are provided with Stirling class A-30 boiler. rated at 400 hp. and having 4008 sq. ft. of heating surface. The thir furnace has a class A-21 Stirling waste-heat boiler rated at 300 hp. with 2805 sq. ft. of heating surface. The boilers are not baffled. The waste-heat boilers are placed on a platform 17 ft. 3 in. above the level of the furnace charge floor. The waste gases from the furnace pass by a vertical uptake flue, 4 by 3 ft. inside at the point where it enters the chamber, to a brick chamber from which the gases pass over a bridge wall and into the boiler setting. The uptake flue and chamber are constructed of silica brick. Each furnace has a steel stack 125 ft. high, measured from the boiler floor. The stacks have a 41/2-in. firebrick lining and are 5 ft. in diameter

Jan 1, 1934

[ ] Utilizing tendencies for low grade ores in the Sudbury District of Ontario to cave after higher grade ore has been mined, International Nickel Co., of Canada, Ltd., is recovering millions of tons of nickel-copper ore once regarded as submarginal. Inco is working lower grade ore than ever mined before from its underground operations because of the caving method and metallurgical practices. In the caving method, blocks containing as much as 1.5 million tons of ore are undercut. As ore from the undercut block is withdrawn, the block to be mined breaks away and starts to disintegrate as it moves downward. Inco is also using the blasthole method, using explosives to break slices of harder, tougher ore from solid material. Inco has built a new concentrator at one of its most recent shafts for handling the increased tonnages of low grade ore. The concentrator presently has a 10,000-ton per day capacity, and is scheduled to be increased to 12,000 tons. Hoisting from the mine is by push-button control and the ore is milled on the spot. A 7 ½ -mile pipeline carries bulk concentrate to reduction plants at Copper Cliff. Giant crushers, weighing 165 tons each, have been installed underground. Twenty-ton electric locomotives haul ore to the crushers. The expansion program is expected to lift total annual production of nickel in the free world to 375 million pounds annually, an increase of 150 million pounds. Inco is presently mining more than 1 million tons of ore per month from combined surface and underground operations.

Jan 1, 1952

By Thomas V. Falkie, Robert Stefanko

Much has been said and written recently about the manpower problem in the mining industry. The coal segment of the industry has been scrambling to staff and man its companies and operations in order to accommodate the current boom, and there are some interesting side- lights and developments which deserve further attention from coal mining people. This column will deal with the manpower problem in general and the plight of the professional-the mining engineer-in particular. At this point in the game, it is desirable and perhaps necessary to ask ourselves if there really is a manpower problem and, if so, how serious it is. Suprisingly, there are varying and conflicting answers to this question. If we are talking about warm bodies, then in most mining areas there is no problem. If, however, we are talking about skilled or trained people-at all levels-there are apparently serious shortages, especially in the coal industry and in the U. S. Bureau of Mines. To define quantitatively the present and future need for mining professionals is a formidable task, to say the least. Without pretending that these figures are anything but an educated guess, we feel there is an immediate need for about 1000 mining engineers right now and a continuing need for about 300 mining school graduates per year (double last year's number) for the next ten years in order to take up the slack, provide for attrition and maintain a normal growth rate. Mining companies, large and small, are just now beginning to realize that the industry is undergoing a revolution, It is no longer possible to design, build and operate coal mines by the "seat of the pants." Production demands, the new health and safety law and the inevitable new legislation on surface mining will require more engineering, more planning and new technology. There are mine operators who need mining engineers and don't even know that they need them. This could mean rough going for the small operator. It surely means that there will be a trend toward increasing the ratio of technical to nontechnical employees and the ratio of technical employees to dollars of capital towards levels comparable with other highly mechanized industries.

Jan 1, 1971

By Enrique Touceda, Henry M. Howe

This paper gives the composition of the iron and slag at different stages in the " air-furnace" process of preparing " hard metal," or white castriron, for conversion into malleable cast-iron by annealing. The details of the process are given in an appendix. One of us had been trying for years to work some chemist of some of our malleable-iron plants up to a degree of enthusiasm which would lead him to make such an investigation. It would have had the advantage of the greater familiarity with the conditions which one habitually on the spot must have. Failing in this, he made use of an opportunity which presented itself of taking samples here represented, with such fairness as the conditions permitted, holding firmly that a rough approximation to the truth is better than the complete lack of data, or that a bird in the hand is worth two in the bush. We hope that this attempt may stimulate others effectively to duplicate this work, and thus correct or confirm it. Our results are shown in Table I. and graphically in Figs. 1 arid 2. Discussion.—At the time when the first two samples were taken, the metal and slag were still too sluggish to permit fair sampling, and not until sample 6 were the conditions really favorable, because at the time of the fourth sample the metal was not fully melted, and even at the time of sample 5 it was still sluggish. Indeed, the slag was probably very heterogeneous throughout, because it took up silica and alumina rapidly from the bottom, and because it was so siliceous as to be sluggish at this relatively low temperature. This hetero-geneousness is exaggerated in the two samples of slag 8, apparently by the great viscosity due to its extraordinary acidity. Note that the manganous oxide of one sample is about two and

Jan 1, 1909

By V. W. Buys, R. E. Havener

11.3-1. Basic Principles. Communications systems available for application to surface mining operations can be divided into basic categories. These are: 1. Wired systems requiring some type of metallic conductor 2. Nonwired systems, or those commonly referred to as space-radio systems. Under the heading of wired systems, telephones of the ringer type utilizing magnetos were used in the early pit operations. These are still being used in underground mining operations where calling is accomplished by ringing a code made up of short and long rings. While the standard Bell Telephone Systems have not been applied extensively in underground mining, they have been used in open pit operations but have the disadvantage of using multiple pair cables which must be installed and maintained as the mining operations proceed. They have the advantage however, that when a Bell System is installed in a surface mining operation, communication is available not only within the operation but to any point in the world through the facilities of the world-wide Bell Systems. A second type of communication available is the audio system or public address system requiring the use of a special audio cable made up of shielded pairs for the loudspeaker and microphone circuits. Audio systems have one outstanding advantage over most telephone systems in that, with a high-powered amplifier, a paging call can be heard over and above the high ambient noise conditions usually found at a surface mining operation. However, they have the disadvantage of requiring special cable which must be installed and maintained. Another type of wired communication system available for surface mining is that of carrier frequency equipment similar to that used in underground mining operations. In this system, transmission is accomplished by means of a frequency modulated carrier that travels over the underground trolley wire, the rail on which locomotives travel, and adjacent telephone wires.

Jan 1, 1968

By G. Czupryna, S. Natansohn

Electrowinning is the prevalent technique for recovering silver from wastes generated in silver-tungsten electrical contact fabrication. Such scrap is placed in a permeable plastic basket, which constitutes the anode compartment, and is suspended in a larger cell where the cathode is mounted. A silver nitrate solution is used as the electrolyte and, upon application of an electric field, the silver migrates to the cathode where it deposits. At times, there is tungsten migration to the cathode compartment and consequent co-deposition with the silver. This W contamination, which may amount to several thousand mg/L (oz per gal), necessitates additional purification of the deposited Ag and its removal would, therefore, be advantageous. Eliminating the W impurity also extends the operating period of the cell with corresponding increases in the Ag output and savings in labor costs. The solution to this problem lies in the selective removal of the W from the AgNO3 electrolyte either by liquid-liquid or liquid-solid extraction. Although W extraction in the liquid-liquid mode with a quaternary amine or other reagents as extractants appears feasible, particularly in view of the low pH (about 1.5) of the system, this approach was not considered because it is essentially a batch-type process. It is a more elaborate industrial operation than extraction by ion exchange resins. Implementing the latter process consists of passing the electrolyte from the electrowinning cell through an ion exchange column which would extract the tungsten selectively and returning the tungsten-free stream to the cathode compartment. This process continues until the W extraction efficiency decreases (as a result of resin loading) below an acceptable value. The electrolyte is then directed through another, similar column while the W values are eluted off the first one and the resin is regenerated for another cycle. Thus, two columns in a parallel flow pattern provide the means for continuous processing of the electrolyte feedstock.

Jan 1, 1984

By H. De Cizancourt

Peche1bronn.—So far Pechelbronn is the only producing district. Figures are given in Table 2 covering the main features of the field, but these figures call for the following remarks: First, Pechelbronn should not' be considered as a single unit, it appears, but as a succession of small oil fields, each of which is affected by very variable conditions. Consequently, certain figures concerning production per acre, production per acre-foot, pressure conditions and thicknesses of oil sands would be so misleading that they have been omitted here. Second, as regards production methods, attention is drawn especially to the fact that 42 per cent of the oil is extracted by the use of shafts and galleries and the remainder by pumping wells. Exploitation, formerly confined to Oligocene sands, has been extended recently to Jurassic and Triassic oil-bearing formations. Gabian.—This small oil field, discovered in 1924, is almost exhausted. Exploitation to date is restricted to three wells. There were no drilling activities in 1933. Exploration.—During 1933, two exploration holes have been started in France. The first, in the vicinity of Lavelanet (Ariége) on the Dreuille anticline, has reached the depth of 2400 ft,.; the second, in the Autun Permian Basin, is drilling at 1300 feet. Northern Africa Morocco.—Drilling operations have been on a large scale in Morocco. In the Gharb district (Souk el Arba area), the deepest well was abandoned in 1933 at 7014 ft. Small irregular productive horizons were encountered in the Miocene at shallow depth, oil and gas showing in the Eocene, but no commercial oil field has been discovered. In the Djebel Tselfat, near Petitjean, a small production of oil was obtained from a Jurassic horizon. In the meantime deeper formations are being explored and a new structure in the vicinity is being tested. In Eastern Morocco, a well is drilling near Taza. Production in Morocco, about 2400 bbl., has not been listed on Table 2, owing to its origin—exploration wells.

Jan 1, 1934

By Ernest Robinson

SINCE the early nineties, there has been a persistent belief in some minds that petroleum in commercial quantities exists in Montana. It is, however, only comparatively recently that commercial produc-tion has been secured. . The earliest deep boring in the plains region of Montana was made in what is now Blaine County, in 1890, by the town of Chinook in an effort to secure artesian water. The well reached a depth of 956 ft. without developing an adequate supply of fresh water, but the drillers reported shows of oil and gas. In 1892, the Quartermaster's Depart-ment of the U. S. Army drilled a hole at Fort Assini-boine, northwest of the Bearpaw Mountains, in essentially flat-lying sediments to secure water for the military establishment. This well reached a depth of 1500 ft. and shows of oil and gas were reported. In 1903 and 1904, two wells were drilled within what is now the Glacier National Park in an effort to develop oil production. Shows of oil and gas were encountered at several horizons but no commercial production was brought in. The extraordinary geological conditions in the area where these wells were drilled should be mentioned. The thrusts from the southwest which, in other places along the Rocky Mountain front, resulted in folding, here developed the great Lewis overthrust fault. It is in fact largely to this fault that the magnificent scenery of the Glacier Park is due. A great thickness of Algonkian strata belonging to the Belt series was thrust northeastward over the upper Cretaceous sediments. The derricks under which the wells referred to were drilled were in moun-tains composed of very old rocks but the holes were drilled through Cretaceous sediments.

Jan 7, 1923

By L. S. Panyity

THE State of Ohio is among the pioneers in the production of oil and gas. Numerous anticlinals, such as the Macksburg, Cow Run and Newport, have been thoroughly developed, and the pools found in connection with them are quite in accord with the structural theory. Numerous oil and gas pools found in the Berea sand, however, demand a different explanation. The study of these pools belongs to the sub-surface geologist, as it is possible to understand the factors controlling "off-structure" accumulations only after a careful study of well records. By carefully analyzing the various 'conditions over a large territory, it is possible to understand the otherwise meaningless mass of data that one may have at hand, and put it into tangible shape, from which various conclusions may be drawn. The territory here discussed includes Belmont, Guernsey, Muskingum, Noble, Monroe, Morgan, Washington, Athens and Meigs counties, containing the majority of the prolific oil and gas pools of the Carboniferous system in southeastern Ohio. The general dip of the strata is to the southeast, the entire territory lying on the northwestern flank of the Appalachian geosyncline. The best known oil- and gas-producing horizon in the territory is the Berea sand, which lies near the lower part of the Mississippian, with the Sunburry shales (the coffee-shales of the driller) above, and the Bedford shales below it. The Bedford is underlain by the thick Ohio shales. The Ohio and Bedford contact is considered to be the dividing line between the Carboniferous and Devonian systems. The Berea is one of the most persistent of recognizable oil and gas horizons; its outcrop has always been found in its expected place, and it has always been penetrated whenever the drill went deep enough. It is not expected, however, even of the most uniform formations, that no lithological variations should occur, and the Berea is no exception. Nevertheless, there appears to be a certain regularity in its variation, the main features of which directly affect the accumulation of petroleum.

Jan 8, 1918

By E. M. Frizzell

Introduction In 1956, the first mobile crusher was installed in a limestone quarry in Hover, Germany. These early mobile crushers solved the problem of wet and soft ground conditions that did not permit the use of haulage trucks due to the high cost of building and maintaining the haulage roads. Quarry operators also wanted to take advantage of continuous belt conveyor haulage systems and the resulting cost savings. European mines, particularly the coalfields, are in soft materials that allow use of bucket wheel excavators and their following continuous haulage system of belt conveyors. Quarry operators, with this background knowledge of belt conveyors in mining, easily accepted the conveyor concept, once in-pit mobile crushing solved the problem of size reduction of mine-run-rock required for conveyor application. Four years after the initial mobile crusher installation, the first report published on the subject appeared in the December 1960 issue of Mining Engineer (Kochanowsky, 1960). With this early background and basis for direction, mobile in-pit crushing and conveying have increased to more than 74 installations. The capacity, type of crusher, and material being processed appear in Table 1. These data in Table 1 indicate that experience to data has been heavily influenced by limestone installations of less than 1 kt/h (1102 stph). Most of these installations were directly fed by a mine face excavator because of the limestone quarry ground conditions. Crusher Configurations Crushers systems developed to date have varying mobility capabilities. These range from fully mobile units that are used continuously in this mode to fixed, permanently located in-pit crushers. The following terms are presented to help distinguish the range of mobility within the configurations of "mobile" crusher systems planned or now in use. Mobile Crusher The crusher works at the mine face, is directly fed by an excavator, and moves in unison with the excavator on its own transport mechanism as the mining progresses. An example is the unit delivered in 1976 to Yamama Cement Co. in Reyadh, Saudi Arabia.

Jan 1, 1986

By N. Cabrera

IN a recent paper Kuczynski' studied the rate at which the crack between a metallic plane and a spherical particle of the same material is filled up gradually when heated at temperatures near the melting point. If x is the radius of contact between plane and sphere (fig. I), Kuczynski shows experimentally that x5 = At [1] where t is the time. Assuming that the mechanism of transport of matter is the volume diffusion of vacant lattice sites, he is also able to prove Eq 1 theoretically. The constant A contains as a factor the self-diffusion coefficient of the metal and he shows that the values for this coefficient deduced from his experiments yield the same activation energy as that calculated by other methods, which is a confirmation of this point of view. Kuczynski has also considered theoretically the law of growth of x which would be expected if surface diffusion were the important mechanism. He suggests that x should then obey a law of the form x7 = At, and claims to be able to decide the mechanism involved from the observed law of growth., The purpose of this note is to prove this incorrect. On the contrary, when the mechanism is surface diffusion Eq 1 is also obeyed, but with a different constant A. Following Kuczynski, we suppose the bottom of the crack (surface A A) to have an average radius of curvature p. As a result of this curvature the concentration of adsorbed atoms in this surface, n(p) per cm2, will be smaller, and the concentration of vacant lattice sites in the neighborhood, N(p) per cm3, will be larger than the corresponding concentrations, n(w) and N(w), for a flat surface. For all practical cases we can write Thomson's formula in the form n(co)— n(P) N(P)—N(cc) _ 2a-a" n(oo) JV(co) kTp [2] where u is the surface energy of the metal and a the interatomic distance. 1. Let us now consider the mechanism of surface diffusion. We suppose the concentration of ad-

Jan 1, 1951

By Andrew A. Blair

It is now well known that certain pig-irons give a considerably smaller percentage of sulphur when determined by evolution-methods than when determined by oxidation-methods. The most striking examplcs of such irons are those made either wholly or in large part from New Jersey magnetites containing more or less titanium. It is never safe to use an evolution-method on such iron; for it is quite common that the sulphur result by evolution is only one-half or even one-third as great as that obtained by oxidation. For this reason, evolution-methods should be discarded, except in the analysis of pig-irons known to contain the sulphur in a state of combination from which it is evolved as sulphuretted hydrogen on treatment with hydrochloric acid. A good example of an iron containing, in the residue, sulphur insoluble in hydrochloric acid having come to our attention, it was determined to try to isolate a suspected insoluble sulphide. A large piece of high-silicon gray-forge iron was accordingly selected as the most promising material to work on. This piece was dissolved slowly, through several months, in dilute hydrochloric acid, aided by the electric current, yielding a soft graphitic residue. The object of dissolving a mass of iron, instead of drillings, was to prevent the crushing, by the drill, of any insoluble crystalline compound that might be present. The first step in the preparation was to break up the graphitic material and put it through bolting-cloth of 157 meshes to the linear inch. This was done by crushing the mass under the fingers on the bolting-cloth fastened over the top of a beaker, while a stream of water from a wash-bottle washed the finer portions through the cloth. The suspended matter was allowed to settle. It was then transferred to a platinum

Jan 1, 1902

By W. G. Woolnough

There has been no noteworthy increase in production during 1935; but, on the other hand, there have been ample manifestations of a considerable increase in interest and activity in connection with petroleum prospecting. The Lakes Entrance field, in the State of Victoria, on the coast some 120 miles east of Melbourne, remains the only actual producer; and this production, consisting of lubricating stock devoid of light fractions, is very small in amount. Arrangements have been completed under which a series of "scout bores" for structure testing in the region of Lakes Entrance will be sunk by the Government of the State of Victoria, assisted by a subsidy from the Federal Government. Prospecting In the State of New South Wales, brilliant geological research in very difficult country, carried out by geologists of Oil Search Ltd., has revealed several previously unsuspected domal structures in the Sydney-Newcastle coal basin. These have been mapped in detail, and a test well is being sunk at Kulnura, 10 miles west of Wyong and 40 miles north of Sydney. At the date of writing this well has reached a depth of 1250 ft., 10-in. casing having been set at 1248 feet. Superficial formations consist of the Hawkesbury sandstone and Narrabeen beds of the Hawkes-bury system (fresh-water Triassic). It is anticipated that the upper coal measures of the Kamilaroi (Permo-Carboniferous) will be entered almost immediately. The objectives of the drilling are the upper and lower marine beds of the Kamilaroi system, which are regarded as promising as potential source—and reservoir—beds for oil. At Mulgoa, 30 miles west of Sydney, a bore is being sunk by the same company, Oil Search Ltd., to test for natural gas on a well defined structure located by the company's geologists. Noteworthy flows of gas have been encountered, but nothing approaching a commercial supply has been struck. It is considered probable that the gas has been derived

Jan 1, 1936

D. J. DEMOREST,* Washington, D. C. (written discussion ?).-This paper is a real contribution to technical science; it will make it' easier to think accurately about the inner workings of a blast furnace. I was rather surprised to read that the authors regarded as a new discovery the idea that a molten mixture of CaO, A1203, and Si02 is a molten solution of the compounds of these oxides rather than of the oxides in each other. Surely no. chemist with an active respect for the known facts of chemical affinity could believe that these oxides could be melted together without forming compounds, and that these compounds would then dissolve in one another. This work does, however, help to establish what it was supposed must be true. I think it is worth while, in the light of the work of the Geophysics Laboratory, this work of the Bureau of Mines, and that of previous investigators, to visualize what happens as a charge passes down through a blast furnace, thinking especially of the slag-forming materials. These are chiefly kaolin (Al203.2SiO2.2H2O), quartz, and limestone. These substances do not undergo much change until the limestone decomposes at about the middle of the furnace, whereupon the chemical affinities of CaO and SiO2 must begin to he active; especially if there is any amorphous Si02 present. This forms CaSiO3, and the SiO2, CaSi02 and Al2-032SiO2 then come together to form the binary and ternary eutectics so well located by the work of the Geophysics Laboratory. No matter how much lime has been charged into the furnace, the formation of this eutectic will start it about the same height in the furnace and the gangue will start to get pasty at the same height. If the charge is such that the

Jan 4, 1918

By J. A. Bartnik, Gerald D. Rose, William H. Benson

New techniques in the magnetite and heavy media beneficiation industries demand more efficient magnetic dispersion and flocculation of the finely ground particles. Demagnetizing coils must produce several major effects, such as improving classification and screening efficiency, decreasing moisture content in filter cake and improving separation selectivity and green pellet properties. Likewise, magnetic flocculators must increase filtering rates and the settling rates of solids, improve magnetite recovery and produce cleaner water. To improve the design of equipment and to conduct tests leading to the optimization of such dispersion and flocculation, a program was initiated at Eriez Magnetics. The major conclusions reached are: 1. Laboratory and plant scale tests conducted on magnetite products show that a demagnetizing force of 450 rms oersteds at 60 cycles for 1/20- second duration will depolarize natural magnetite particles coarser than approximately 10 microns. This has been found satisfactory for most applications. 2. Effective flocculation of magnetite was obtained when a slurry with more than one percent magnetite was exposed for a period of approximately 1/15 second to a 600-gauss field. 3. The cost of demagnetizers (or flocculators) increases rapidly for larger diameter pipes. In order to reduce the cost, narrow rectangular sections are recommended for magnetic flocculators. 4. For minimum operating cost, permanent magnetic flocculators are ideal, chiefly because they do not require any maintenance and have no operating cost. 5. A newly designed electro-demagnetizing coil with high heat dissipation and a nonmetallic core provides high efficiency and long life. 6. To select the correct magnetic flocculator (or demagnetizing coil) the following information is necessary: a. Magnetic product susceptibility b. Magnetic product coercive force c. Percent of magnetic product d. Flow rate e. Viscosity f. Structure of magnetic product

Jan 8, 1968