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By Robert Hunt

ONE of the most serious and important economic administrative problems facing American railway authorities to-day is that of their rails, and it is one to which much thought, is being given, not only by the executive officers of the railways and the manufacturers of the steel rails, but also by State and National commissions. It is realized by many and admitted by some that the present situation is one which cannot continue. The roadways of railways must be made more secure, or the weight of rolling stock and the speed of trains must be lessened; and the desired result must be attained with the minimum outlay of money, both in expenditure on plant and in cost of operation. If the investment per mile is too large, or through the lessening of tonnage and efficiency of equipment the cost of operation is too great, the desired and demanded cheap service cannot he rendered to the public. Therefore, the weight of equipment cannot be greatly reduced, and lessening the rapidity of service would be far from satisfactory; consequently, the safety of the roadway must be secured with the least practical outlay. It is imperative that the roadbed should be properly graded, with the fewest practically possible curves; that it should have good ballast, be well drained, have good ties properly spaced, and be laid with sound rails of suitable weight, efficiently joined together, and that the whole property be carefully and intelligently cared for. My province is to treat of the sound rails. During the last few years there has been renewed interest in and discussion of that question, and I know that many rail makers not only have been and are desirous of maintaining the highest standards of manufacture which they may have attained, but have been and are seeking to better their product, in several instances devoting much time and money to that end. At the same time, they realize that the cost of any improvement in quality which they may accomplish must be kept within certain commercial bounds; and that fact is as fully understood by their patrons as by themselves, and it should be kept in mind by all who discuss the question.

Jan 2, 1914

By R. F. Shurtz

The author proposes a method used with some success on a magnesite deposit at Gabbs, Nev. He believes this procedure to be more sound than the blind practice of assigning uniform quality to large, soinetimes vast blocks or ore on the basis of analyses made of a small number of samples. When an ore deposit is evaluated on the basis of core sampling, questions always arise as to how much weight should be given the various sample grades and how the deposit should be divided into specific volumes assigned to corresponding grades. For a tabular deposit it is customary to use the so-called zone-of-influence. This zone is usually defined as the polygon in the plane of the deposit having corners halfway between a given core drill intersection and each of the nearest neighboring intersections. The volume of the ore in this polygon is assigned the analysis obtained from the drill core taken at the intersection. In massive or irregular deposits, volumes of various shapes may be defined with respect to the locations of drill core samples. These volumes may be regarded as three-dimensional zones-of-influence; the theory involved in assigning the values of the central analyses to the ore in the volumes is the same as that used in the case of a tabular deposit. The zone-of-influence method was used in evaluating one of the magnesite deposits at Gabbs, Nev.'-"

Jan 1, 1960

By S. C. Jones, J. A. Davis

This paper describes displacement mechanisms of micel-lur solution slugs, displuced by a thickened water "mobility buffer", in a glass micromodel and in consolidated Berea sandstone cores. Colored motion pictures, taken through a microscope, recorded interactions on a pore-to-pore bash in the micromodel. Production and differential pressure data from consolidated cores previously waterflooded to residua1 oil saturation revealed displacement mechani.sm.s macroscopically. Oil is displaced miscibly, while interstitia1 water is displaced immiscibly by the injected micellar. solution slug. Part of this water is dispersed and carried near the lead ing edge of the .slug, and some may remain as a residual saturation. Thickened water displaces any residual water. It also emulsifies with the. slug material, thereby displacing it. The displacement sequence forms banks of oil and water with relatively constant fractional flows, saturations, and mobilities. The mobility of oil and water flowing ahead of the .slug defines .slug viscosity required for stable displacement. Equations are presented that describe. several aspecis of the displacement flow behavior: oil breakthrough, oil cut during production of the stabilized bank, breakthrough of banked water and the resulting decreased fractional flow of oil, fluid mobilities, etc. Breakthroughs, calculated from the equations, are compared with experimental data. Slugs of micellar sollution, ranging from 1 to 5 percent PV, produced unusually high oil recoveries (up to 100 percent) in previously waterflooded consolidated cores. Investigation of the effect of mobility buffer size on oil recovery indicated that recovery is reduced in 3-in. X 4-ft cores for mobility buffer sizes .smaller than 50 percent of the pore volume. Introduction A new oil recovery process,* conceived in 1962, utilizes a slug of micellar solution' that has sufficient viscosity to avoid an unfavorable mobility ratio with respect to the oil and water it displaces. These micellar solutions are composed of hydrocarbons, water, and surfactants, and may contain electrolytes and co-surfactants. The micellar solution is displaced by a "mobility buffer". The mobility buffer is a bank of reduced-mobility fluid, preferably an aqueous polymer solution. The entire system is displaced by unthickened water. This paper describes some of the microscopic and macroscopic displacement mechanisms observed during laboratory development of the fluids for a potential field test. Microscopic phenomena were observed photographically in a specially constructed glass flow model and macroscopic data were taken from constant rate, tertiary displacements conducted in Berea sandstone cores. Qualitative Description of Micellar Solution Flooding This section qualitatively describes displacement mechanisms that occur when a slug of micellar solution is injected into a previously waterflooded core. The slug completely removes oil from the portion of core it contacts, and banks oil in the process. The oil saturation in this bank and the flowing WOR reach definite, fixed values that are determined by water and oil mobilities and slug characteristics. This zone of constant WOR and oil saturation will be called "stabilized oil bank" in the following discussion. When this stabilized bank reaches the outlet end of the core, the oil cut jumps from zero to a constant value equal to the fractional flow of oil. Saline water has little or no solubility in the slug. Because of this. the slug displaces in-place brine immiscibly. During slug injection, most of the brine is displaced ahead of the slug, some is carried along in the leading portion of the slug, and part of the brine may become immobile. The immobile, residual brine is later miscibly displaced by thickened water. Displacement of all the oil and only part of the water during slug injection results in a higher fractional flow of oil ahead of the slug than occurs when all the water is displaced after injection of thickened water is begun. The slug spontaneously emulsifies fresh (low-salt content) water. By emulsification, the slug can become infinitely diluted, and hence totally displaced, by thickened water. Fluid saturations in the core are shown schematically in Fig. 1. Parts A and B show conditions before and after the start of the thickened-water injection, respectively. Since thickened water displaces any residual brine by-

Jan 1, 1969

AT the meeting of the Board of Directors held on June 25, 1926, and in response to numerous in-dividual suggestions for changes, a committee on Re-vision of the Constitution and By-Laws of the Insti-tute was appointed, consisting of C. F. Rand, Archi-bald Douglas and H. Foster Bain. Various confer-ences were held, much correspondence conducted and a preliminary draft was prepared. It proved imprac-ticable to complete the work in time to submit the matter to the membership for approval or disapproval at the annual meeting in 1927, and the Committee was continued with instructions to prepare a report as a basis of action in 1928. After Mr. Rand's death George Otis Smith was appointed in his place and the tentative draft herewith submitted has been pre-pared in its present form by Messrs. Smith, Douglas and Bain, though not differing in any material mat-ter from an earlier draft approved by Mr. Rand. In preparing this the Committee has kept in mind primarily the desirability of simplification and of making the By-Laws conform to the actual practice of the Institute as worked out through experience. The Constitution and By-Laws adopted in 1912, and which with minor amendments only still govern the Insti-tute, are full of specific provisions regarding pro-cedure; such as that laid down for guidance of the Papers and Publications Committee. Many of these have proved unworkable and in practice have not been always strictly followed. It now seems wise to write into the Constitution and By-Laws only the general fun-damental principles to he followed and to provide for such easy change in methods of following them out as will permit efficient conduct of the business. It is this thought that has guided the Committee in rewrit-ing many of the sections. With this in view also the Constitution, as such, has been shortened to the brief-est feasible statement of fundamentals. All matters relating to means of making these principles effec-tive have been put into the By-Laws or in the hands of committees whose work is subject to control and whose rules are subject to approval or disapproval by the Board of Directors. Many suggestions for changes have come to the Committee that have not been incorporated in this draft. Some of these are in themselves excellent but have not been incorporated here because the Commit-tee discovered no sentiment for them such as would be likely to secure their approval, or found them out of harmony with the general plan followed herein.

Jan 9, 1927

By H. J. Gluiskoter

The chlorine content of the coals in the Illinois Basin ranges from 0.00% to more than 0.60%. The chlorine content of the Herrin (No. 6) Coal has been mapped on a regional scale and, in general, increases with the depth of the coal. The depth-chlorine correlation exists because the coal is in apparent equilibrium with the composition of the ground water associated with it, and the salinity of the ground water generally increases with depth. At least part of the chlorine can be easily removed from the coal in the laboratory. In a natural weathering experiment, chlorine values decreased markedly during an 8-week period. Results to date indicate that none of the coals studied has a sufficiently high chlorine content to make it unusable in high-temperature steam boilers, although special steps may be necessary in the preparation or utilization of some of the highest chlorine coals. Investigations into the occurrence and distribution of chlorine in Illinois coals have been in progress at the Illinois State Geological Survey for over 35 years. Since 1948, chlorine analyses of face channel samples and of drill core samples of coal have been made routinely. The increased interest in chlorine and alkalies in coal in the U.S. followed that in Europe, where power plants during World War II were called upon to produce at higher levels than previously and with less down time for maintenance. Higher steam temperatures were reached, resulting in increases in the amount of fouling of external heating surfaces and in corrosion of boiler tubes when high chlorine coals were used. Early studies of the problem showed that coals with high chlorine content were more likely than those low in chlorine to cause difficulties in installations fired with powdered fuel. Crossleyl reported that the first rule of thumb developed for British coals was that coals considered to be high in chlorine (more than 0.30%) caused the most trouble, those intermediate in chlorine content (0.15% to 0.30%) were less likely to cause difficulties and those low in chlorine (less than 0.15%) generally were not associated with alkali bonded deposits and corrosion. However, this relatively simple picture was not adequate to characterize the difficulties that could be expected during the utilization of a large number of coals and Crossley1 developed another scheme for assessing the chances of superheater corrosion. This scheme took into consideration the observation that coals high in sulfur as well as chlorine are more likely to cause corrosion and fouling than coals low in sulfur and high in chlorine. Crossley also considered the ash content. When two coals had the same chlorine and sulfur contents, the one with the greater amount of ash would be the less likely to cause difficulties. Knowing only the amount of chlorine in a coal obviously will not give all the answers. Indeed, the significance of the chlorine content has been much discussed and it has been suggested that perhaps the total alkalies are a better indicator of possible troubles. The observation that the deposits that form

Jan 1, 1968

Sec. 1. The membership of the Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that no member of any class whom residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the claw of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1944

By J. C. Marquardt L., J. A. Bratt, J. P. Hunt

The Quebrada Blanca copper/molybdenum prospect lies on a dissected plateau in the high Andes of Northern Chile. The Superior Oil-Falconbridge Group began exploration of the Property in 1977 under a joint venture foreign investment agreement with the Chilean government. Quebrada Blanca is a relatively high grade secondarily enriched porphry copper deposit. Primary mineralization occurred 38 million years ago and accompanied quartz monzonite intrusive. Early disseminated Primary mineralization was followed by hydrothermal mineralization, mineralized breccia, and post-mineral faulting. After supergene enrichment Quebrada Blanca was buried under late Tertiary gravels and then partially re-exposed in Quaternary time. During the past five years, a successful exploration program has developed an open-pit mining reserve, provided samples for bulk metallurgical testing, and located more than adequate supplies of water for future operations. The main orebody is amenable to conventional metallurgical treatment and contains more than 400 Mt (441 million st) of recoverable open-pit ore at about a 1:1 overall stripping ratio. The average millhead grade during the first six years of operations will exceed 1.5% Cu, plus recoverable molybdenum values. Several hundred million tons of additional reserves are available in the surrounding districts

Jan 1, 1984

By Gloyd M. Wilkes

The eastern section of the Park City district is drained to an elevation of 6300 ft, by means of the Ontario drain tunnel owned and maintained by Park Utah Consolidated Mines Co. This elevation represents a depth of 920 ft, in Park City Consolidated Mines Company's property. When development below the 900-ft. level was commenced, sinking was attempted through an incline winze in the fissure. The intensely fractured quartzite forming the walls of the vein could not be held after water was encountered, so it was decided that further sinking should be done in a vertical winze far enough in the foot-wall to be in the more solid quartzite outside the fractured zone containing the vein. Progress was good until a depth of 200 ft. below water table was reached, where the flow of water became serious. Sinking progressed 300 ft., to the 1200-ft. level, and there approximately 750 gal. of water per minute was being pumped. The last 20 ft. of sinking cost more than $200 per foot direct charges, whereas the over-all cost for the 300 ft. was $100 per foot. This high last cost was caused by excessive lost time in pumping. Crosscutting to the vein disclosed the fact that the 1050-ft. level had been developed only after drainage had been effected from the 1200-ft. level, but that the 1200-ft. level could not be opened because of the great amount of water encountered when the fractured zone was intersected. The ground in the fractured zone is so finely crushed that it precludes any possibility of economic support when it is wet. Furthermore, mining costs were found to be prohibitive after caving of vein walls had taken place as a result of an attempt to drive drifts before complete drainage had been effected. More than 3000 gal. per minute was pumped from the 1200-ft. level and the water table remained 75 ft. above this plane even after five crosscuts were driven to the fractured zone at 50-ft. intervals along the strike of the fissure from a footwall drainage drift. It was evident, therefore, that complete drainage must be effected before the fractured zone could be opened in any future development. After extensive investigations in this connection, a well-drilling campaign was decided upon to effect drainage of the fissure in advance of sinking and level development, so that all mining operations would be carried on in dry ground. Drilling Procedure A crosscut was driven through the hanging wall of the fissure on the 1050-ft. level, which was the deepest dry level at the time, to a predetermined location from which a vertical hole should reach the fractured zone at about 400 ft. below this level. A drill station was made and a raise was driven over the location for the hole, to act in lieu of a derrick or drill tower. This raise

Jan 1, 1943

By Gloyd M. Wilkes

The eastern section of the Park City district is drained to an elevation of 6300 ft, by means of the Ontario drain tunnel owned and maintained by Park Utah Consolidated Mines Co. This elevation represents a depth of 920 ft, in Park City Consolidated Mines Company's property. When development below the 900-ft. level was commenced, sinking was attempted through an incline winze in the fissure. The intensely fractured quartzite forming the walls of the vein could not be held after water was encountered, so it was decided that further sinking should be done in a vertical winze far enough in the foot-wall to be in the more solid quartzite outside the fractured zone containing the vein. Progress was good until a depth of 200 ft. below water table was reached, where the flow of water became serious. Sinking progressed 300 ft., to the 1200-ft. level, and there approximately 750 gal. of water per minute was being pumped. The last 20 ft. of sinking cost more than $200 per foot direct charges, whereas the over-all cost for the 300 ft. was $100 per foot. This high last cost was caused by excessive lost time in pumping. Crosscutting to the vein disclosed the fact that the 1050-ft. level had been developed only after drainage had been effected from the 1200-ft. level, but that the 1200-ft. level could not be opened because of the great amount of water encountered when the fractured zone was intersected. The ground in the fractured zone is so finely crushed that it precludes any possibility of economic support when it is wet. Furthermore, mining costs were found to be prohibitive after caving of vein walls had taken place as a result of an attempt to drive drifts before complete drainage had been effected. More than 3000 gal. per minute was pumped from the 1200-ft. level and the water table remained 75 ft. above this plane even after five crosscuts were driven to the fractured zone at 50-ft. intervals along the strike of the fissure from a footwall drainage drift. It was evident, therefore, that complete drainage must be effected before the fractured zone could be opened in any future development. After extensive investigations in this connection, a well-drilling campaign was decided upon to effect drainage of the fissure in advance of sinking and level development, so that all mining operations would be carried on in dry ground. Drilling Procedure A crosscut was driven through the hanging wall of the fissure on the 1050-ft. level, which was the deepest dry level at the time, to a predetermined location from which a vertical hole should reach the fractured zone at about 400 ft. below this level. A drill station was made and a raise was driven over the location for the hole, to act in lieu of a derrick or drill tower. This raise

Jan 1, 1943

By William Phillips

THE earliest mention of the sulphur deposits in what is now Culberson County, Texas, seems to be contained in "Explorations and Surveys for a Railroad Route from the Mississippi River to the Pacific Ocean, United States War Department, 1853-54." Captain John Pope (he was not commissioned Captain until 1856) had charge of one of the divisions of the Survey. In his report on the geology of the route, William P. Blake noted the analysis of a greenish earthy powder from the bed of Delaware Creek, at the springs, which contained 18.28 per cent. of free sulphur. The report states: "From the chemical examination of the waters of the spring, by Dr. Booth, it appears that chloride of sodium is the principal solid ingredient, but considerable quantities of sulphide of sodium are present. * * * * * The waters from the springs examined by Dr. Booth were alkaline, but it is possible that some of the springs are acid; and in this case the precipitation of sulphur would ensue on the mixture of the acid waters with those charged with alkaline sulphurets and the origin of the deposits of sulphur would he thus explained." This is the first reference to the existence of sulphur in that region, the first mention of the character of the water found there and the first suggestion as to the' origin of the deposits. The possibility of the existence of acid waters was confirmed by E. M. Skeats, nearly 50 years later.1 In this publication, Skeats says that the water from the sulphur deposits in Section 11, Block 114,, Township 5, contains 79.08 grains of free sulphuric acid per gallon. This locality is about 13 miles (21 km.) south of Delaware Creek and about 35-miles (56 km.) east of the Delaware Springs. The next published reference to the existence of sulphur in Trans-Pecos Texas is in the First. Annual Report of the Geological Survey of Texas, 1889, page 226, where W. H. von Streeruwitz mentions that sulphur is found in that region, but gives no further information. In the

Jan 9, 1917

By I. Lowthian Bell

THERE has been probably no improvement introduced into the manufacture of iron which created more surprise in the minds of practical smelters and of scientific men than Neilson's discovery of the hot blast. In 1829, Messrs. Dunlop & Co. consumed at the Clyde Works, near Glasgow, nearly 7 3/4 tons of coal to make a ton of pig iron, of which about 20 cwts. was employed under the boilers of the blowing engines, leaving nearly 7 tons for the consumption of the furnace itself. In the year 1833, by heating the air to 612° F. (322° C.), they reduced the 7 3/4 tons to 3 tons by the mere burning of 8 cwts. of coal in the apparatus for raising the blast to this temperature. The statement just given is strictly true in a commercial sense, but when we come to consider the question as one of physical science, it is necessary to eliminate some of the conditions which conduced to so extraordinary a result. Anterior to Neilson's time the fuel employed in smelting iron was coke, and it was supposed at that period, erroneously, however, that coal in its raw state, when burned with cold air, was totally unfit for the purpose in question. This mineral, as it was obtained from the Lanarkshire coal-field, contained about 35 per cent. of volatile matter, but the process of charring it was performed in so unskilful a manner that instead of receiving 88 cwts. of coke from 135 cwts. of coal, 60 cwts. only was the product of the operation. Again, the reduced consumption of carbon in the furnace itself was accompanied by a corresponding diminution of blast, and this was followed by an economy of half a ton in engine coal. After making a proper allowance, however, for all these collateral circumstances, we are within the mark when we admit that in actual coke, which is really the form the fuel has to assume before it is burnt in the blast-furnace, not less than 30 cwts. was saved by heating the blast to 615° F. (322° C.). This unexpected economy, be it remembered, was obtained by the combustion of the 8 cwts. of coal, somewhat wastefully applied in the hot-air apparatus. Numerous have been the opinions advanced by different authorities in the scientific world to account for the apparent anomaly, but none,

Jan 1, 1877

By I. Lowthian Bell

THERE has been probably no improvement introduced into the manufacture of iron which created more surprise in the minds of practical smelters and of scientific men than Neilson's discovery of the hot blast. In 1829, Messrs. Dunlop & Co. consumed at the Clyde Works, near Glasgow, nearly 79 tons of coal to make a ton of pig iron, of which about 20 cwts. was employed under the boilers of the blowing engines, leaving nearly 7 tons for the consumption of the furnace itself. In the year 1833, by heating the air to 612' F. (322' C.), they redoccd the 79 tons to 3 tons by the mere burning of 8 cwts. of coal in the apparatus for raising the blast to this temperature. The statenlent just given is strictly true in a commercial sense, but when we come to consider the question as one of physical science, it is necessary to eliminate some of the conditions which conduced to so extraordinary a result. Anterior to Neilson's time the fuel employed in smelting iron was coke, and it was supposed at that period, erroneously, however, that coal in its raw state, when burned with cold air, was totsally unfit for the purpose in question. This mineral, as it was obtained from the Lanarkshire coal-field, contained about 35 per cent. of volatile matter, but the process of charring it was performed in so unskilful a manner that instead of receiving 88 cwts. of coke from 135 cwts. of coal, 60 cwts. only was the product of the operation. Again, the reduced colisumption of carbon in the furnace itself was accompanied by a corresponding diminution of blast, and this was followed by an economy of half a ton in engine coal. After making a proper allowance, however, for all these collateral circumstances, we are within the mark when we admit that in actual coke, which is really the form the fuel has to assume before it is burnt in the blast-furnace, not less than 30 cwts. was saved by heating the blast to 615° F. (322° C.). This unexpected economy, be it remembered, was obtained by the combustion of the 8 cwts. of coal, somewhat wastefully applied in the hot-air apparatus. Numerous have been the opirlions advanced by different authorities in the scientific world to account for the apparent anomaly, bat none,

By Fulton B. Flick

The micrography and macrography of aluminum and its alloys present certain difficulties. Many of the difficulties attendant on the micrography have been removed by methods developed during the past few years, notably those of E. H. Dix, Jr.1 The development of grain size in aluminum and its alloys may be equally troublesome, yet comparatively little detailed attention appears to have been given to it. Satisfactory reagents are available for the development of such structurcs in ferrous and most non-ferrous metals, but those applied to aluminum and its alloys, i. e., alcoholic or aqueous solutions of sodium hydroxide or hydrofluoric acid are not entirely satisfactory. Hanson and Arch-butt,2 in speaking of these two reagents, state that "These two reagents give fairly satisfactory results, but they sometimes produce badly tarnished surfaces from which the surface deposit is difficult to remove." It has been our experience that neither of these reagents is to be entirely relied on for developing structures suitable for study or photography. This means that when the etch fails to produce satisfactory results the specimen must be repolished, through the 000-paper at least, and then etched with another reagent. This procedure entails a considerable loss of time, and the final results may not be all that might be desired. However, the reagent to be described, although not a panacea for all etching troubles, has improved results so markedly that it is felt that it & worth offering as a grain-size etch generally applicable to aluminum and aluminum alloys. Czochralski3 in 1915 mentioned the application of a solution of 10 to 20 c. c. concentrated hydrofluoric acid in 100 c. c. absolute alcohol, etching in this reagent being followed by dipping in concentrated hydrochloric acid soliltion.

Jan 1, 1925

By T. S. Mohibatsela, R. V. Ramani, C. V. Manula

The Mineral Engineering Department of The Pennsylvania State University has developed a suite of computer models for anthracite open pit mining (Fig. 1)1 Individual sub-systems have been developed to (a) interpolate geologic field data to obtain coal tonnages, waste volumes, and strip ratios; (b) simulate equipment performance on selected pit profiles to generate data required to choose coal and waste removal equipment; and (c) evaluate selected cost factors to determine either a rate of return for a specified selling price or vice-versa. This paper describes the application of two of these subsystems, namely, the Reserves Model (GEOL) and the Open Pit Materials Handling Simulator (OPMHS), and how these may be applied for the selection of equipment for a prime anthracite mining site.2

Jan 1, 1981

By Guillermo Zuloaga

The iron deposits of the Imataca Range of Venezuela, which occur along the Orinoco River, in the northern border of the Guayana Highlands, have lately attracted attention on account of their economic possibilities. Many deposits occur in this area; some of slight economic importance and others that may rank with the largest masses of high-grade iron ore of the world. The geology and the character of the ores seem to be remarkably similar to those of the large iron deposits of Brazil. In the investigation of the Venezuelan deposits a definite relationship has been found between the mineralization of the large orebodies and igneous intrusions, especially norites and granites. The following paper is the result of a field and laboratory investigation of the ore deposits. The field work was done during the months of February and March of the year 1929, partly in the company of Prof. W. H. Newhouse. The laboratory studies have been made in the Massachusetts Institute of Technology, under the supervision of Professor Lindgren and Professor Newhouse. GENERAL GEOLOGY OF GUAYANA HIGHLANDS General Geography and Physiography The Sierra de Imataca proper occupies a narrow belt along the south bank of the Orinoco River, in the northeastern part of the State of Bolivar and in the western part of the Delta Amacuro Territory of Venezuela. The State of Bolivar is generally known as the Venezuelan Guayana, as it forms part of the same physiographic province of the Guianas and northeast Brazil. In general the Venezuelan Guayana is an extensive plateau, sloping gently towards the Orinoco River to the north and towards the Atlantic Ocean to the east. In the northern part mountains are rare, and consist mainly of elongated low hills. Towards the British Guiana-Brazil boundary, table mountains with vertical cliffs are found forming the ranges of Parima, Roraima and Pacaraima. General Geology The Guayana Highlands are the northern extension of the Brazilian Archean shield. Only a few scattered masses of sediments remain on its

Jan 1, 1935

By Guillermo Zuloaga

The iron deposits of the Imataca Range of Venezuela, which occur along the Orinoco River, in the northern border of the Guayana Highlands, have lately attracted attention on account of their economic possibilities. Many deposits occur in this area; some of slight economic importance and others that may rank with the largest masses of high-grade iron ore of the world. The geology and the character of the ores seem to be remarkably similar to those of the large iron deposits of Brazil. In the investigation of the Venezuelan deposits a definite relationship has been found between the mineralization of the large orebodies and igneous intrusions, especially norites and granites. The following paper is the result of a field and laboratory investigation of the ore deposits. The field work was done during the months of February and March of the year 1929, partly in the company of Prof. W. H. Newhouse. The laboratory studies have been made in the Massachusetts Institute of Technology, under the supervision of Professor Lindgren and Professor Newhouse. GENERAL GEOLOGY OF GUAYANA HIGHLANDS General Geography and Physiography The Sierra de Imataca proper occupies a narrow belt along the south bank of the Orinoco River, in the northeastern part of the State of Bolivar and in the western part of the Delta Amacuro Territory of Venezuela. The State of Bolivar is generally known as the Venezuelan Guayana, as it forms part of the same physiographic province of the Guianas and northeast Brazil. In general the Venezuelan Guayana is an extensive plateau, sloping gently towards the Orinoco River to the north and towards the Atlantic Ocean to the east. In the northern part mountains are rare, and consist mainly of elongated low hills. Towards the British Guiana-Brazil boundary, table mountains with vertical cliffs are found forming the ranges of Parima, Roraima and Pacaraima. General Geology The Guayana Highlands are the northern extension of the Brazilian Archean shield. Only a few scattered masses of sediments remain on its

Jan 1, 1935

THE book covers principally the assaying of silver and gold and the determination of these values in ores, sweepings, and base metal. It seems to have been written more for the goldsmith and jeweler than for the primary producer of metals. There were approximately sixty different substances needed in the operations described and not over a dozen different types of raw material (ore, matte, crude or alloyed metal) are mentioned. The methods of separation used were essentially simple and reasonably reliable, though the processes were not sufficiently understood to permit the selection of the simplest effective ingredients, and there was a great tendency to employ complicated fluxes, with unnecessary repetition of long-continued heatings indicative of a leisurely pace of life. Practically all the processes described are based on a few chemical facts: the inability of gold to combine with sulphur, while silver and the base metals form easily fusible sulphides; the ready oxidation of base metals; and the ii- solubility of gold in nitric acid. Fluxes serve to make earthy impurities fusible, and to carry oxidizing or sulphurizing ingredients. Many of the processes of assaying had changed little up to the beginning of the present century. Even as late as 1924, when the writer took a University course in fire assaying, the crucibles, cupels, scorifiers, molds, and tongs were identical with those of the sixteenth century, though the wind furnace had a stack on it and the muffle for cupelling was gas-fired.* The fluxes were purer, but of the same essential composition. That this branch- or twig-of metallurgy had not advanced in any funda-

Jan 1, 1949

By A. S. Michaels, R. S. Timmins

A study of the effect upon oil recovery from an un-consolidated porous medium of chromatographic transport of selected reverse-wetting additives during water displacement is described. Flow tests were performed on hydrocarbon oil-saturated sand columns (containing connate water) into which small volumes of short-chain aliphatic amine solutions were introduced during water flooding. Concurrently, meusurements of oil-silica contact angles, oil-water interfacial tensions and oil-water distribution coefficients were measured us a function of additive concentration. Certain treatments were found to cause a slight reduction in oil recovery, while others produced a significant increase (up to 50 per cent of the normtzl irreducible rninimum oil saturation). Recovery eficiency was correlated most satisfactorily with the maximum degree of reverse wetting produced during additive transport; conditions which resulted in only mild oil wettability of the sand reduced recovery, while those favoring strong oil wetting increased recovery. A mechanism of reverse-wetting additive action during chromatographic transport is developed which ascribes the results to transient changes in oil-solid contact angle during flow, with consequent release of oil trapped by capillary forces. Implications of these observations with regard to improved waterflood efficiencies are discussed. INTRODUCTION The need for finding improved methods of oil production is amply illustrated by the large volume of oil considered economically unrecoverable by existing production practice. Water flooding has long been an excellent method of secondary recovery. However, even in those areas of a formation which are well swept by a water flood, 20 per cent or more of the oil remains trapped within the formation and is not recovered. This trapping of oil within the pores of the rock structure results primarily from interfacial forces. If these interfacial forces were altered, it is possible that the trapped oil could be released and recovered. The addition of surface-active agents to a water flood to alter the interfacial properties of the oil-water-solid system has received considerable attention as a method of increasing oil recovery. Studies of surfactant treatment have yielded varied and, in some cases, apparently conflicting results. Increased oil recovery using surface-active agents has been reported by a number of investigators. Others have found that use of surfactants in a water flood either has no effect upon oil recovery or decreases it. Since surface-active agents tend to alter the formation wettability and oil-water interfacial tension simultaneously, several investigators have tried to determine the role these two factors play in oil recovery. Data have been presented which indicate that the most desirable condition for the solid surface is strongly water-wet. Other results indicate that, although breakthrough recovery may be less, the greatest ultimate recovery is obtained when neutral wettability prevails.", " The desirability of low interfacial tension seems to depend upon the wettability of the formation. Reports of higher recoveries, when the interfacial tension is high in a water-wet system and low in an oil-wet system, are at odds with reports of increased recovery in water-wet systems when surfactants which decrease the interfacial tension are added to the water flood. A review of previous work studying the effects of using surface-active agents in a water flood shows that these agents produce widely different effects and that opinions as to the role of the various interfacial properties are diverse. The consensus, however, is that the interfacial properties are quite important in the displacement of oil from a porous medium by water. Even in those investigations where appreciable increases in oil recovery resulted from treatment with a surface-active agent, economic considerations generally made practical application of the treatment unattractive because surfactants tend to be adsorbed within the formation. This adsorption would necessitate using large quantities of surfactant if all of the flood water were treated to contain a given surfactant concentration, even if this concentration were quite low. Preston and Calhoun suggested that the principles of chromatography could be applied to the use of surface-active agents as a means of increasing oil recovery. A small volume of surface-active material is injec-

By R. A. Falconer, H. L. Lovell

With increasing requirements for fine coal cleaning and the many advantages of the cyclone operating on a coal-water slurry, a series of studies designed to achieve an enhanced understanding of the cyclone parameters has been pursued. The purpose of this investigation has been to vary a series of dimensional parameters with an experimental 15-in. diam hydro-cyclone, and to determine the relative effects of parameter variations upon ash and sulfur removal. This study of the hydrocyclone is a continuation of a series of investigations, conducted in the Dept. of Mineral preparation at The Pennsylvania State University, which are directed toward the removal of ash and sulfur constituents from fine bituminous coal by size-density separations in cyclones, and toward a fuller understanding of the complex mechanisms involved in such separations. The purpose of this investigation has been to vary a series of dimensional parameters with an experimental 15-in. diam hydrocyclone, and to determine the relative effects of parameter variations upon ash and sulfur removal. Of special interest was the response to cone angle variation, since it is the high included cone angle that generally distinguishes the hydrocyclone as a gravity separator rather than a classifier. DESCRIPTION OF THE HYDROCYCLONE Fig. 1 is a dimensional drawing of the hydrocyclone used in the investigation. The unit was designed and fabricated by Heyl and Patterson, Inc., for experimental use. The dimensional parameters considered were: 1) Three cone sections having included angles of 45, 60, and 95,degrees, 2) Three 3 1/8 in. diam vortex finders having lengths of 15, 17, and 19 1/2 in., 3) Three 4 1/16 in. diam vortex finders having lengths of 15, 17, and 19 1/2 in. 4) Two apex sections having diameters of 2 and 2 1/4 in. The feed inlet orifice had a fixed diameter of 3 in. The hydrocyclone test installation was made at The Pennsylvania State University pilot plant at Barnes-boro, Pa., which operated at 50 tph. During the period that the hydrocyclone was tested, research was in progress at the Barnesboro site to reprocess refuse material from a near-by coal preparation plant in

Jan 1, 1968

By T. Egleston

ALTHOUGH the success of metallurgical operations depends so largely on the possibility of finding proper refractory materials, which enter so prominently into the cost of their operations, it can hardly be said that our knowledge of them is in a very satisfactory condition, or even that we know very much about them, beyond a few facts which have been gathered through their use. Experience, as a general thing, is an excellent master, but the requirements of * This article was written at the suggestion of the Committee of the Institute on Refractory Materials, with a view of calling attention to the anomalies and difficulties of the subject. It was hoped that its discussion would eventually lead to the appointment of a Commission, by the great metallurgical interests of the United States, to investigate the whole subject, since it is believed that a better and cheaper artificial product can be made than any now in use, and that many other important incidental results would be accomplished by such an investigation.

Jan 1, 1876