Search Documents

By C. W. Vaupell

The Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barccnite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. Introduction The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarel1o,2 Mactear3 and Merri114 have described the geology and the early operations in the district, and Bar-cena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. Location The village of Huitzuco lies in the north central part of the State of (Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1941

By Gerald Sherman

IN the southern field of the anthracite region of Pennsylvania, many of the coal seams dip at angles of 40° to 50° from the horizontal. For transportation purposes, "tunnels" are driven across the coal measures and, occasionally, "rock gangways," beside the seams and parallel with them. The use of gangways driven in country rock appears to be increas-ing, as they avoid the maintenance' of long gangways in coal, which eventually are driven to the colliery boundaries, and permit mining from a number of intermediate blocks without interference. The rock consists of slates or sandstones of moderate hardness, which may range into very hard, highly siliceous, fine-grained conglomerates. In this distinctly bedded formation,' the direction of the heading, whether parallel with or across the structure, makes it necessary to distribute the drill holes in a different pattern to break the ground, but does not change loading conditions. In 1932, practically all the mucking was done by hand, and it was the established custom to use four men on two drills for drilling and breaking the ground, and five for loading it, out. A driver and mule was needed in addition, to assemble the rock cars at a siding or branching track in the rear, pending their final disposal. This might occupy the driver's whole time, or if the length of haul were short, he might be able to do other useful work. It was thought possible in 1932 to reduce the cost of driving such headings in rock by mechanical loading, and to investigate this subject a scraper loader was used in a section of tunnel then being driven. Opera-tions while driving 195 ft. of this tunnel using a scraper loader were care-fully observed. Time studies were made of the loading, and records made of the routine of breaking ground, but not in such detail. Tunnels or gangways in the colliery are 7 ft. high above the rails, by 10 ft. wide, which requires a minimum of 8 ft. in height, broken to allow for rails and ties. This cross section is of sufficient size to permit the use of any one of several types of power loaders, but for this demonstration if was found most convenient to use a scraper loader.

Jan 1, 1936

By F. Cadena, Fred C. Bond, Walter L. Maxon

Grinding is one of the major problems in present-day milling practice, and in many cases, it represents one of the main items of expense. It becomes necessary from time to time, to compare grinding practice in one plant with that in another plant, and in making such comparisons, it would be very desirable were there available accepted standards of grinding resistance for the materials involved. Such a set of grinding constants would also be of considerable value in planning new grinding installations. There have been some tests published, notably those of Lennox,' which have been generally cited as a basis for such comparisons. Most of the tests made have been based upon open-circuit grinding, in which a weighed sample of the ore was crushed to pass a certain mesh, and was then ground under certain conditions, either wet or dry. Grinding was continued until a certain desired fineness was attained, and the comparisons based on the grinding time, or the samples were all ground for a certain specified length of time and comparison based upon the screen analysis of the products. Such methods have been acceptable where the ore was to be ground in open circuit. However, in modern milling practice, many grinding problems involve closed circuits wherein the oversize returns to the mill and a large circulating load builds up. A method of testing that does not take the circulating load into consideration might yield results quite different from those to be expected in practice, because the minerals in the ore that offer maximum resistance to grinding will accumulate in the circulating load up to an equilibrium value. Thus the nature of the ore charge in the mill at any instant may differ greatly from that of the new feed, with a consequent error in the rate of grinding determined by such a method. For example, let it be assumed that an ore to be tested consists of equal parts of difficult grinding mineral and easy grinding mineral. This is to be compared with an ore used as a standard, and consisting of minerals which are all of about the same grindability. If a comparison

Jan 1, 1935

By Plato Malozemoff, A. M. Gaudin

IN modern practice the major portion of an ore is reduced to flotation size by fine grinding. As the result of grinding fine enough to liberate most of the minerals, a substantial portion (generally 5 to 15 per cent) of the ore is inadvertently reduced to a size much finer than that necessary for liberation. This portion of most flotation pulps is very refractory to recovery by flotation. A reduction of one-quarter or more in recovery in this range of extremely fine particles can be observed. The loss in metals caused by overgrinding is appreciable. That this loss is characteristic of very fine particles has been suspected for some time;(l)† however, it was definitely quantified only recently.(2) Definite reduction in float-ability with reduction in particle size beyond a critical size of maximum floatability can be accepted now as an established fact. Formulating the Hypothesis In looking for the cause of the ill behavior of the finest particles it may be well to consider the essential differences between fine and coarse particles. A difference that immediately comes to mind is their intrinsic difference in size and consequently in relative extent of surface. If one agrees that attachment of mineral particles to bubbles must follow direct encounter of particles with bubbles one is forced to conclude(3) that the probability of encounter between a mineral particle and a bubble varies directly as the size of the particle, provided the particle is small compared to the bubble. In other words, the finer the particle the poorer its chance of being recovered in a given time of flotation. There is an effect, implicit in this theory, which should overcome the effect of excessive fineness of the particles; namely, flocculation of the particles. The floccules can be conceived as being simply larger particles and therefore capable of becoming attached to bubbles. And, indeed, in all the cases in which a sulfide mineral of near-colloidal size was successfully floated the mineral (but not necessarily the gangue) was flocculated. Moreover, it was shown experimentally(4) that galena previously flocculated by inorganic flocculators and then added to gangue

Jan 1, 1935

By Henry F. Heblby

HOW often has the thoughtful observer pondered the apparent contradictions experienced in the weather? One can take records of two days, one in the winter and one in the summer. The "degree days1' indicate that space heating and domestic load were present in one case and not in the other. The Business Index may be about the same, indicating that the industrial activity of the area and its concomitant use of fuel were about the same. Thus the volume of the products of combustion released to the atmosphere varied only as related to the space heating demand. Yet on one day in winter the atmosphere may be clear and bracing, while on a summer's day the air is thick and murky and the visibility sharply reduced. The situation may be reversed. What are some of the factors that contribute to the creation of these conditions? These few notes have been prepared to indicate some of the influences that are exerted on the problem. The Sources of Atmospheric PolLution The industrial area of Pittsburgh, Pa., has been a dominant center for the production of iron and steel for over one hundred years. In fact, with the growth of the numerous auxiliary processes Allegheny County which contains Pittsburgh is prob- ably the most industrialized county in the world. In addition, the type of manufacture carried out in this area is predominantly dependent on thermal energy (heat). That energy is supplied from coke and coal produced in the vicinity of Pittsburgh Indicative of the stupendous quantities of fuel that are employed in this industrial area's economy, the following (Table I) taken from the U. S. Census (1940) may be of interest. In tonnage consumed in the area, the figures are equally impressive: Annual Tons oF Coal Metallurgical Industries.... 35,000,000 to 40,000,000 Commercial Installations (Pgh.)................. 1,500,000 Domestic hand-fired) (Pgh.)................. 750,000 An influence that has never been fully appreciated by many individuals is the fact that no matter what adventures the gases of combustion experience as they pass through the various processes, uti-mately the spent gases are discharged through chimneys to the atmosphere.

Jan 1, 1949

By C. W. Vaupell

The Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barccnite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. Introduction The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarel1o,2 Mactear3 and Merri114 have described the geology and the early operations in the district, and Bar-cena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. Location The village of Huitzuco lies in the north central part of the State of (Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1941

By Charles White Merrill

Money is one of the most .pervasive elements in human life. The compensation for a workman's daily efforts is expressed as a wage and is measured in money. What an individual may consume depends largely on his income which also is expressed in terms of money. If he would start an enterprise its size would be determined in large part by the amount of money available for capitalization and its success would be measured in net income expressed in money. In short, the most widely used common denominator for comparing merchandise, real property, jobs, enterprises, gross national product, or personal success is money. Despite this use of money by almost everyone past infancy to express his appraisal of the in- numerable values he sees around himself, the complexity of the device called money makes its nature and workings a mystery to most users. Some of the difficulty in understanding money results from the fact that it has three distinct but interrelated functions: (1) a medium of exchange, (2) a unit of account, and (3) a store of value. In many statements about money the discussion moves from one function of money to another without the speaker or the listener recognizing the changes. For example, the housewife says "We took the money we had saved up to make the down payment and after twelve monthly payments the television will be ours." When this housewife spoke of "saving up the down payment" she referred to money in its function as a store of value; when she spoke of "the down payment" she was using money as a medium of exchange; and when she referred to the "monthly payments" she spoke of money as a unit of account. Another cause of confusion in understanding money is its paradoxical nature in that it represents both the power to produce and the power to consume. For example, when the rich uncle dies one nephew may regard his inheritance as an opportunity to buy a farm and leave the ranks of the wage earners to become an independent producer, whereas the other nephew may regard his portion as the means of living in complete leisure as a pure consumer.

Jan 1, 1959

By W. H. Blauvelt

The technical and engineering problems in the manufacture of coke are today the problems of the byproduct oven. Except in a few special localitics, practically no beehive ovens have been built in the United States for the last 5 or 6 years except as renewals of old plants, and during these years the total number of beehive ovens in existence has been steadily falling. On the other hand, the number of byproduct ovens has increased from 4624 in 1911 to a total of about 7660 in operation at the end of 1917; with 2800 building, this makes a total of about 10,460 which will be in operation in 1918, or shortly thereafter. Preliminary Government estimates place the total production of coke for 1917 at 56,600,000 tons, the largest tonnage in the history of the industry. Of this 34,000,000 tons, or 60 per cent., was beehive, and 22,-600,000 tons, or 40 per cent., was byproduct coke. Some time in 1918 the production of byproduct coke should pass the beehive output, and when the byproduct ovens now building are completed the total byproduct capacity will be about 40,000,000 tons of coke per annum, which is over 70 per cent. of the record-breaking total coke production of 1917. The reasons for these changes in the coking industry are familiar to all of us, and need not be discussed here. Improvement in Oven Design Since the byproduct oven was brought to this country from Europe, in 1892, it has been radically improved, and from the point of view of American metallurgical practice it is safe to say that the American ovens arc superior to those of Europe. The points of superiority are mainly those of larger units and larger output per unit, and the greater extent to which labor-saving machinery has been introduced. The increased output is largely due to the use of silica refractory material, which permits higher heats and shorter coking time than are employed in Europe. The modern American oven will carbonize commercially more than 20 tons of coal per day, and contrary to the European idea that slower

Jan 1, 1920

By Oswald J. Heinrich

(Read at the Amenia Meeting, October, 1877.) THE deposit of rock salt along the shores of Lake Huron, in Canada, has been brought before the public during the last six months, in consequence of the developments made by the diamond drill at Goderich. It is likely to be of more than common interest in the future, since now actual operations have been commenced to exploit the deposit and work it by regular mining. The methods of mining rock salt being but little known in this country, it may be of interest to make a few general remarks in regard to them before entering, upon the description of this new mining enterprise. According to the conditions under which salt is found in nature, various methods have been resorted to, in course of time, to make it available for the human race. They consist in : A. Natural or solar evaporation. B. Artificial evaporation, either exclusively or in connection with the former. C. Mining the rock salt in its natural state, and converting it to a marketable product, if need be, by simply pulverizing it. Without going into the details of the various methods of making salt available in an economical point of view, dependent on its degree of purity, or on various local influences, we cannot refrain from. alluding to the general principles which influence the mining and manufacturing of salt in countries where they have been carried on for hundreds of years. ECONOMICAL CONDITIONS FOR SUCCESS. Salt being one of the articles of prime necessity, and one universally distributed throughout nature, it must always be sold at a comparatively low price. It would even be quoted in the market at prices far below those now ruling, if it were not for the high duties generally imposed upon it, for purposes of state revenues. But looking closer into the subject, it will be found that this duty is probably one of the least oppressive, although in some countries it exceeds sixfold the cost of profitable production. To produce the article at the lowest possible cost requires, therefore, a

Jan 1, 1878

By C. W. Vaupell

THE Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barcenite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. INTRODUCTION The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarello,2 Mactear3 and Merrill4 have described the geology and the early operations in the district, and Barcena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. LOCATION The village of Huitzuco lies in the north central part of the State of Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1937

By John B. Hastings

The occurrellce of such a large amount of gold in the Hart-eel granite, even though the surmised existence of similar areas is not new, brings freshly to mind the pegmatite type of mag-matic differentiation lately brought again to attention by occurrences at Silver Peak, Nev., described by Spurr; and in Alaska, described by both Spurr and Brooks. In both localities granitic rocks or dikes are thought to pass into metalliferous quartz-veins. An interesting association in this connection is the occurrence of diamonds in residual pegmatitic clay of Sail Juao de Chapado, Brazil, described by Derby :' (P. 142) "Bodies of pegmatite are quite common in the older rocks of Brazil, both in the diamond regions and elsewhere, occurring not only in the gneiss and granite, but in the schistose series as well. Those that have been examined are dike-like in their mode of occurrence and granitic in composition.'' (P. 143) '" The question of the eruptive or secretionary origin of pegmatites has long been a subject of discussion among geologists.... The recent studies .. seen] to have clearly established that most if not all of them are essentially eruptive masses, though possibly modified in some way by aqueous agencies. Even before becoming acquainted with the literature of the subject this view had seemed to me to be the only acceptable one as regards the typical pegmatites of Brazil." What is pegmatite ? J. F. Kemp says :2 "... veins or dikes—it is an open question which is the more correct term— are met formed of very coarsely crystalline aggregates of the same minerals that constitute granite. These are called pegmatite and in them is the home of graphic granite, the curious intergrowth of quartz and feldspar, such that a cross fracture of the blades of quartz suggests cuneiform characters.... In regard to the larger veins or dikes it seems improbable that true igneous fusion could have afforded such coarsely crystalline aggregates, and so we are forced to assume such abundance of steam and other vapors, i.e, mineralizers, as to almost, if not quite, imply solution."

Jan 1, 1909

By W. J. Carlson, I. lwasaki

Manganese and silica in nonmagnetic tailings from the direct reduction-magnetic separation step were so closely associated that no physical concentration methods were effective. Dilute sulfuric acid dissolved manganese and iron rapidly; manganese in the form of silicates was virtually insoluble in sulfuric acid solutions, thereby governing the maximum extraction attained by leaching. Autoclave leaching at elevated temperatures and at high oxygen pressures reduced the iron extraction to less than one tenth without affecting the manganese extraction. There was an indication that autoclaving solubilized the manganese silicates appreciably. Elimination of iron from leach solutions was carried out by aerating the solution in the pH range of 6.5-7; a platinum-calomel electrode pair provided a reliable indicator for the end point of iron removal. The purified leach solutions were free of interfering impurities for the recovery of manganese as metal, dioxide, or carbonate. Manganiferous iron ores of the Cuyuna Range, Minn., are too low in iron content to be directly useful as iron ores, and too low in manganese content to be termed manganese ores. Common methods of physical beneficiation such as gravity concentration and flotation have not been successful in upgrading this material. The R-N process, when applied to manganiferous iron ores,1'2 produces sponge iron by direct reduction of iron oxides, while leaving manganese as manganous oxide. From fine grinding and magnetic separation of the reduced ore, a tailing is produced which is relatively rich in manganese and low in iron content. The nonmagnetic tailing can readily be leached with acids and then further processed to recover manganese in various forms. In this way, two processes, neither of which would be an economic solution to the Cuyuna ore problem by itself, may be combined to produce two marketable products, thereby rendering the over-all process economically more attractive. This article reports on the results of a leaching study on the nonmagnetic tailings, both in a batch agitation vessel and in an autoclave; on the problems involved in the purification of leach liquors by aeration; and on the recovery techniques used to produce manganese metal by electrolysis, manganese dioxide either by electrolysis or by autoclaving, and

Jan 1, 1968

By James Herbert Bartlett

I desire, very briefly, to call the attention of the Institute to the iron trade of the Dominion of Canada. A wonderful development is now going on in Canada. The completion of the Canadian Pacific Railway, and the numerous extensions of the various railways all over the country, combined with the progress made in nearly every kind of manufacture, is drawing attention to the field offered in Canada for the profitable employment of capital, and specially to the opportunity there is for the manufacture of iron. In a paper presented to the Institute at the Halifax meeting,* the writer gave a review of the varions attempts to manufacture iron in Canada. The facts then presented were not such as to offer much encouragement to any one to embark in similar enterprises under the conditions then existing, but, happily, these conditions are now changed, and an early development may be anticipated. There are two reasons which make the present time an appropriate one to direct attention to the field offered for enterprise in this direction, the first being the very favorable reports of the experts who examined and reported on the exhibit of minerals at the Colonial and Indian exhibition, held in London, England, last year. The exhibits there of coal and iron attracted so much attention that at the request of the Iron and Steel Institute a paper on the " Ironmaking resources of our Colonies as illustrated by the Colonial and Indian Exhibition," was prepared and read at the last meeting of the Institute.? This report of 135 pages is very exhaustive, and the conclusion arrived at, so far as Canada is concerned, is, that she has in many parts of the country every natural facility for the manufacture of iron. The second and more important reason is the recent change in the Canadian customs tariff inaugurated in May last. The tariff is now generally two-thirds of the American tariff, in addition to which the Government, in order to encourage the manufacture of iron, grants a bounty upon pig-iron made in Canada out of Canadian ore.

Jan 1, 1888

By W. S. Landis

In brief, this is the story of an attempt to Americanize a process originally developed in Europe. The story will be recited in two sections, the first dealing with the process as developed by the European engineers; the second containing the improvements and modifications of American origin, together with some details of the operating results of the unit as finally assembled. Developments in other directions in this same field have not, up to the present, pointed out an economic future for the process, therefore our record here is largely a report of development progress. Whether some particularly favorable location will be found at some future time for a commercial installation cannot as yet be foretold. The project is now at a standstill. The peculiar tools of the electrometallurgist should be of great interest to the zinc smelter. The low thermal efficiency of the zinc retort, its comparatively small-scale unit and its intermittent cycle as it stood in 1925, should make this art a particularly fertile field for the electric furnace. Yet in spite of years of work recorded in volumes of literature, and an expenditure of large sums of money, there is not a single electrothermic zinc smelter operating anywhere in the world. In this industry the electric furnace plays only a secondary part today. Historical The first serious proposal to use the electric furnace for the smelting of zinc ores was made by the Cowles Brothers in 1885, but their experimental work did not advance the art to any extent. The next investigator of this field was Dr. Gustav DeLaval, a Swedish engineer well known to the industrial world through his development of the centrifugal and the steam turbine. The DeLaval cream separator is a familiar household appliance in most parts of the world. Although Dr. DeLaval commenced his experiments in the field of electric zinc smelting in 1893, it was not until 1898 that he had a practicable furnace, even then operating but intermittently. His work was done at Trollhättan, Sweden. He continued to improve this early fur-

Jan 1, 1937

By C. P. Watson, R. E. Collom

Various chapters already written in the history of development of the North Dome of Kettleman Hills are monotonoysly identical in the one underlying' theme of conservation of oil and gas. Discovered on Oct. 4, 1928, by Milham Exploration Co. with its wildcat Elliot No. 1, the field has been subjected to practically every modern form of production restraint in the name of conservation. The record thus far developed shows that conservation was had for a time, at a price; and that unitiza-tion must be blessed by single ownership or 100 per cent participation to be effective. In fact, incomplete unitization places a heavy handicap upon its participants in the competitive development that follows. Shut-in Agreement of July 25, 1929 Not long after discovery at Kettleman but after the Continental Oil Co. and the Standard Oil Co. had completed several producing wells in the discovery group, came the so-called Shut-in Agreement negotiated at the instance of the Department of the Interior. This agreement became effective July 25, 1929. The fundamental purpose of the agreement was to prevent bringing on production of some 30 wells then being drilled and forestall a flood of Kettleman oil on the market. A cooperative scheme was developed whereby wells in the discovery group would continue to produce. Two of them could not be shut in. Drilling wells would be completed to a water shutoff in top of Temblor and operations suspended. Producing wells would contribute the value of 10 to 25 per cent of their production to the owners of suspended qualifying wells. The percentage rate of drainage contribution was left to a committee or umpire. Some acreage was not placed under the agreement. This same acreage later did not come into the Kettleman Unit Agreement. Several wells on this acreage did not contribute to the drainage fund. The total amount of oil produced during the 17 months of the shut-in agreement, by Milham, Continental and Standard from wells in the discovery group, was 5,297,262.22 bbl. The total amount paid out in "drainage" contributions was $2,046,048.18, representing sales value of 1,266,044.06 bbl. of oil.

Jan 1, 1937

By Heinrich Freyn

THE American iron and steel manufacturer finds himself to-clay barely at the threshold of enormous possibilities for practicing rational economy in the use of fuels. The fuel cost is by no means the smallest of items which enter into the cost of manufacture of iron and steel products, but the great wealth of this country in high-grade fuels, together with a protective tariff, has heretofore made fuel economy relatively unimportant. In Germany, the use of raw coal for the purposes of iron and steel manufacture has been all but abandoned and large sums of money, formerly irrevocably wasted, are now being saved. When scanning the literature of this country devoted to the application of gas power, but little information will be found on a subject which, however, is destined to become of considerable importance in the United States, namely, the use of coke-oven gas for the generation of power in gas engines. This lack of information can be traced to the fact that the regenerative by-product coke oven with its large amount of surplus gas is still far from having attained in this country the universal application which it has found in Europe. This statement needs hardy any corroboration other than the evidence of statistical investigations made by E. W. Parker of the United States Geological Survey, according to which only approximately 25 per cent. of the total coke produced in this country in 1912 was made in by-product coke ovens, whereas 75 per cent. was produced in bee-hive ovens. This entailed the enormous loss of over $80,000,000 in non-recovered by-products, such as gas, tar, and ammonia, without considering the substantial loss due to the non-recovery of benzol from the coal. There are two more or less distinct fields of application of the by-product coke oven: one, to furnish as the main product metallurgical coke of specified quality, and surplus coke-oven gas as the by-product, and the other, to carbonize high-volatile coals, and thus produce as the main product large quantities of gas, high in heat value and rich in illuminants, adapted primarily for domestic heating and lighting, while domestic coke becomes the by-product.

Jan 4, 1914

By R. L. Rickett, N. C. Fick

Despite the large volume of literature on alloys of iron and silicon,' there is little published information dealing specifically with the constitution, at various temperatures, of the alloys containing less than 0.10 per cent carl~on and from 0.5 to 4.5 per cent silicon that are used extensively in the electrical industry. Because such information was needed by those engaged in the production of these alloys in sheet and strip form, the constitution nas determined of a series of commercial silicon steels containing 0.05 to 0.08 per cent carbon and 0.20 to 4.1 per cent silicon, over the temperature range 1300° to 1500°F. These alloys were all from regular production heats and of commercial quality. The results of the tests are given in Fig. I and for comparison the constitution diagram of iron-silicon alloys with 0.01 to 0.02 per cent carbon, taken from the literature, is also presented Material and Procedure All steels were hot-rolled to a thickness of 0.060 to 0.080 in. and used in this condition. Their chemical compositions, including over-all check analysis, and "center" analysis for carbon and silicon, are given in Table I. The so-called center analysis was determined on samples pickled to remove the outer surface and leave only the center third of the gauge thickness—the portion of the sample on which metallographic ratings were based. In most, but not all, of the alloys, slightly higher carbon was found at the center than when the whole strip was sampled; the two methods of sampling show relatively little difference in silicon. Two of the steels, A and E, contain relatively high phosphorus, while I and K are somewhat higher in manganese than the others. The procedure consisted essentially of heating specimens (about 1/16 by 3/8 by 3/4 in.), protected from oxidation or change in carbon content, at a temperature in the desired range and for a selected period, after which they were quenched in iced brine; the degree of transformation that had then occurred was determined by metallographic examination. The soaking periods were selected after preliminary investigation had shown that a con-

Jan 1, 1947

By N. C. Fick, R. L. Rickett

Despite the large volume of literature on alloys of iron and silicon,' there is little published information dealing specifically with the constitution, at various temperatures, of the alloys containing less than 0.10 per cent carl~on and from 0.5 to 4.5 per cent silicon that are used extensively in the electrical industry. Because such information was needed by those engaged in the production of these alloys in sheet and strip form, the constitution nas determined of a series of commercial silicon steels containing 0.05 to 0.08 per cent carbon and 0.20 to 4.1 per cent silicon, over the temperature range 1300° to 1500°F. These alloys were all from regular production heats and of commercial quality. The results of the tests are given in Fig. I and for comparison the constitution diagram of iron-silicon alloys with 0.01 to 0.02 per cent carbon, taken from the literature, is also presented Material and Procedure All steels were hot-rolled to a thickness of 0.060 to 0.080 in. and used in this condition. Their chemical compositions, including over-all check analysis, and "center" analysis for carbon and silicon, are given in Table I. The so-called center analysis was determined on samples pickled to remove the outer surface and leave only the center third of the gauge thickness—the portion of the sample on which metallographic ratings were based. In most, but not all, of the alloys, slightly higher carbon was found at the center than when the whole strip was sampled; the two methods of sampling show relatively little difference in silicon. Two of the steels, A and E, contain relatively high phosphorus, while I and K are somewhat higher in manganese than the others. The procedure consisted essentially of heating specimens (about 1/16 by 3/8 by 3/4 in.), protected from oxidation or change in carbon content, at a temperature in the desired range and for a selected period, after which they were quenched in iced brine; the degree of transformation that had then occurred was determined by metallographic examination. The soaking periods were selected after preliminary investigation had shown that a con-

Jan 1, 1947

By W. H. Bassett

ALTHOUGH brasses and bronzes have been made for ages, a systematic study of their physical properties has been carried out only during the years of the present century. Among these properties may be included those which are to be detected by means of microscopic examination; in other words by the science of metallography. The earlier workers in this field, both in this country and abroad, gave their attention to steel. When the senior author explored the situation in 1902, there was little encouragement to be found in undertaking the study of the non-ferrous alloys. A start was made, and the metallography of the brasses and bronzes, as well as of the copper-nickel- zinc alloys developed materially under his direction. Annealing experiments were begun in 1902, and in the succeeding years the effect of temperature, and the influence of previous working, on the grain size of brass were studied. The conclusions so well known and widely published today were largely reached during those earlier years. In 1905 the first complete annealing series were made. By this it is meant that brass and copper sheet, 5 B & S Nos. hard, was machined into tensile test specimens, then annealed under accurate control for 30 min. at temperatures up to the melting point of the material. Various determinations were made, including tensile strength and elongation in 2 in. There rapidly followed similar series on all of the copper-zinc alloys from 100 to 60 per cent. copper, on the bronzes, cupronickels, and on copper-zinc-nickel alloys. At this point there was published by Grard, in October, 1909,1 the very comprehensive and complete work on the tensile properties of cartridge brass, 90-10 copper-zinc, and electrolytic copper. The excellent photomicrographs in that paper illustrated the changes in structure produced by cold rolling as well as by annealing at different temperatures, but where Grard's work was confined to copper and to two alloys, the investigations in this laboratory have been over the entire fields of the commercial copper-zinc alloys, copper-tin alloys, representative copper-nickel and copper-nickel-zinc alloys as well as aluminum bronzes and others of a more special nature.

Jan 1, 1927

By H. F. Hebley

In recent years, especially in the last decade, great interest has been shown and many advances have been made in the preparation and cleaning of coal. In the major coal-producing countries, the percentage of tonnage cleaned has been increasing ever since 1924. As separating media, both liquids and gases are used, these generally being water and air respectively. Some systems, instead of obtaining separation by the velocity of the medium in which the coal is cleaned, depend on the density of water mixed with sand, or coal dust and shale, or with chemicals such as calcium chloride. In studying the results of coal-cleaning equipment, it will be observed that the efficiency of the cleaning apparatus lowers as the size of the coal decreases. This inability to obtain any marked improvement in the fines has been partly responsible for the installation of dedusting equipment, to remove the fine sizes from the raw coal prior to cleaning. When considering the possibility of installing dedusting equipment, many factors must be taken into account. Very often, but not always, both the ash and sulfur content of the coal increase as the coal size decreases. When bituminous coal, containing soft powdery fusain, is subjected to a wet washing process, the porous fines of the fusain remain in the small coal or in the wash water and delay the dewatering of the washed coal and increase the difficulty of clarification in settling tanks or thickeners. When a dedusted coal is cleaned by a wet process, the sludge recovered from the settling tank often runs so high in ash that the sludge can be discarded without further treatment and still the loss is small. Where treatment of the sludge is desired, however, froth flotation may be used to advantage if the size of the feed is below 1/10 in. Dust from the deduster can be treated in a similar manner. Fusain, which is usually found in the fine sizes, has often a much larger ash content than other coal. Illustrative of this condition is a table of ash contents for the various petrographic constituents of Illinois coal (No. 5 bed) as given by Mitchell' (Table 1).

Jan 1, 1934