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By George B. Clark

7.1-1. Introduction. The fundamentals of blasting involve both the properties of explosives and of the rock being blasted. While the knowledge of property correlation between rocks and explosives for most effective blasting is far more complete, many quantitative evaluations have been made. Four of the most important explosive properties appear to be energy density, bulk density, rate of energy release, and the pressure-time history of the gases produced. Important rock properties are density and porosity strength, and energy absorption properties, including the effective moduli of elasticity. Rock structure also has a marked effect on its breaking properties, i.e., joints, bedding, fractures, alteration, etc. Several mechanisms enter into rock fragmentation by blasting. These include slabbing, radial fracturing, crushing, and bursting by the gas bubble. All of these factors are closely related to properties of both explosives and rock. Slabbing depends upon the character of the first generated stress wave, whose shape and magnitude are a result of the pressure generated by the explosive, its time history, and the resultant response of the rock, including its ability to sustain the stress wave. Actual slabbing, in turn, is a function of the magnitude and shape of the pressure pulse and the tensile strength of rock. Further fragmentation depends to a great extent upon the amount of gas in the bubble and its energy and pressure. Blasting rounds are best designed by taking the above factors into consideration. This is effectively accomplished by use of cratering curves which relate breakage- parameters to the explosive energy. Optimum depths from single charge cratering curves must be adjusted to changes in shot geometry and related to multiple hole blasting. Blasting damage may occur from either air blast or ground waves, and in the latter ease may be due to direct vibration or to settlement caused by vibration. Technical information indicates that blasting damage is often

Jan 1, 1968

By Vic Casaletto

"IntroductionThe Canadian mining industry is under immense pressure to compete with foreign mine operations. The very survival of the Canadian mining industry is threatened by lower ore grades, environmental pressures, high cost of labour, unfriendly tax laws toward exploration and the increasing cost of new technology. In order to compete in the world market, Canadian producers and their suppliers are rethinking age old customer-supplier relationships in favour of preferred supplier relationships which can improve the profitability and enhance the competitive position of both partners.This paper attempts to redefine partnerships with suppliers in the context of a ""win-win"" objective. It will outline the measurable benefits to both partners through a representative product which highlights the keynote structure of any successful supplier partnership The Status Quo...Mines all over North America are plagued with the same recurring questions, ""Who has the best product for my operation at the lowest price... How do we know a product will perform to a supplier's projections after the sale...What do we do if the product fails to perform as expected?"" These questions have been asked by underground mining operators for decades but rarely have long-term solutions with measurable results been achieved.The LHD industry is one example of the status quo where partnerships will provide large gains toward technological advancement, reducing mobile equipment costs. The underground mining industry is out of sync with their surface counterparts in the open pit business.Partnerships with suppliers in the open pit world are not only a standard practice but a culture which has existed for decades. Open pit operators enjoy concepts which fix their mobile equipment costs for the life of the mine and hold the equipment supplier accountable for performance and fleet economics for 60 000 service hours and longer.Manufacturers are attempting to transfer this culture into the underground mining industry. Figure I illustrates the significance of a capital driven decision."

Jan 1, 1994

THE CHAIRMAN (DR. A. R. LEDOUX).-If there ever was a question in the mind of anybody as to whether there are some mining engineers, I think if they would look in the door tonight they would decide there are. We meet here tonight not only to enjoy a smoke and other incidentals which are permitted us in these days, but with a more serious thought in our minds, because that flag, with its 540 stars, only begins to show the number of our membership that are serving the country. We are thinking of them, and when we consider how many of those men are also citizens of one or another of our allied countries, we can imagine that many are tonight thinking of us and perhaps have received, even at the front, notices of our annual meeting and are wondering what we are doing tonight; so our thought this evening will be going out to them, going out to those of our number who are serving in the khaki or in the blue, or in other activities denied to some of us for one reason or another; but, gentlemen, there is one thing we will do now, we will rise and sing together r the Star Spangled Banner. Gentlemen, not only are American citizens here tonight, not only representatives of our country on the Speakers' platform, but. there are representatives of our Allies, and we are going to have the privilege of listening to one or two of the latter, a citizen of the great British Empire and a citizen of France. We will first have the pleasure of hearing Capt. Hodder-Williams. He has been loaned to us to take charge of training Columbia University students, after two years or more in the trenches, and lie carries with him the only German thing in this room, a German bullet in his shoulder. That has not affected either his spirit or his

Jan 4, 1918

By R. H. SWEETSERS

A Discussion of Mr. Hall's paper, read at the Washington Meeting, February, 1905. R. H. SWEETSER, Sault Ste. Marie, Ont. (communication to the Secretary*) :-The recent work of furnace No. 1 of The Algoma Steel Co., at Sault Ste. Marie, Ontario, using for fuel, first all charcoal, then a mixture of charcoal and coke, and finally all coke, upsets the estimates given by Mr. Hall in the last two paragraphs of his interesting paper. Furnace No. 1 was built for a charcoal-furnace, and it was run on charcoal fuel from March 6 until July 9, 1905; then, for a week, a mix¬ture of charcoal and coke was used, and, since then, coke alone has been the only fuel. It is to be regretted that at no time, during the run on charcoal, was there enough charcoal on hand and " in sight'" to warrant blowing the furnace as hard as it should have been blown. During April and May the supply of charcoal limited the amount of blast to about 8,000 cu. ft. of air per min.; in June, to about 8,900 cubic feet. For a few days in July about 10,000 cu. ft. were blown, and then the maximum daily output, 173 tons (2,240 1b.), was reached. At all times the quality of the charcoal was poor, having been made from wood cut from three to four years before. Doubtless this furnace could have produced .200 tons of iron per day, even with this quality of charcoal, provided the supply had been sufficient; and with good charcoal I see no reason why it could not make as much iron per day as it has made with coke. During the one week of using a mixture of charcoal and coke, the changes in quantity of blast and composition of the slag followed each other so closely that no single condition could last long on the furnace. The results were good, and the pig-iron was about the same in quality as that made during the

Jan 1, 1906

IN CHAPTER I it was shown that the approximate market value of the copper produced at the twelve big Porphyry mines from 1905 to 1931, inclusive, was $2,821,300,000. This represented the refined metal ready for shipment to the consumer. In addition, at least $50,000,000 worth of gold and silver had been produced, more than $30,000,000 coming from the Utah mine alone. Consequently, the revenues totaled about $2,871,300,000, as shown in Table 58. Society paid this sum for a given quantity of metal that it wanted for industrial use. Where did the money go? Who were the direct beneficiaries of the creation of this new wealth? These questions this chapter will answer in a general way. Because some necessary data are not available, an exact tabulation in detail can not be made, but Table 58 is believed to reflect with reasonable accuracy the disposition made of the aggregate income from the twelve operations. The word "operations" is used advisedly because the complexity of corporate relations precludes the possibility of picking out companies, as could be done if each enterprise were an independent entity such as Miami, for example. Some explanation of the table and some elaboration of the items under "Outgo" is desirable. In the first place, it is assumed that the sum of surplus current assets existing in various treasuries at the end of 1931 was substantially equivalent to the “new” money that actually was put into the enterprises as a group. Less than $20,000,000 in new capital was realized from securities sold by the Utah Copper Co., the remaining funds coming from earnings. In respect to some of the others, such as Chuquicamata, Inspiration, and Andes, the amount of new money was much greater. However, of the two items-total new capital invested and total current surpluses-the former

Jan 1, 1933

To evaluate the potential for dust reduction, during blasthole drilling, of water or foam applied directly into the drill hole. Approach The Bureau of Mines tested a through-the-drill-steel water and foam injection technique in two noncoal mines to evaluate the method's potential for greater dust reduction. The tests were performed by drilling a series of blastholes for an entire face (a 90 minute time-period). For the first 45 minutes of drilling, foam or water was applied through the drill steel. Blowing ventilation was supplied to the entry about 50 feet from the face. The dust concentration measurements were made by a Real-Time Aerosol Monitor (RAM-I), and the data were read out on a strip chart recorder. The evaluation test results showed that the water or foam injection technique, when used on localized dust sources, can be an extremely effective dust control method. Small amounts of water used in this method have also allowed it flexibility to be used in water-soluble ores such as salt, gypsum, anhydrite, and trona. How The System Works Water or foam is mixed with compressed air (approximately 100-120 psi) with suitable metering systems and forced through the drill steel into the blast hole at the point of dust generation. Because the water or foam is applied at the source, minimal quantities of liquid are needed (0.2 to 0.6 gpm). These low flowrates are sufficient to just moisten the dust emerging from the blast hole, thus eliminating a major source of airborne dust. The wet drilling procedure also eliminates a second source of dust. With dry drilling, the dust from the blast hole falls to the floor. Since this can be a 15-ft drop or more, the impact can send the dust billowing up from the floor, adding to the airborne dust. With wet drilling, the moistened dust merely dribbles down the face.

Jan 1, 1982

By K. C. Carriere

INTRODUCTION The purpose of this section is to introduce the reader to the concepts of computer control of grinding circuits, and to flag some of the opportunities to be encountered, but without becoming overly involved in details of process, equipment or software. It is assumed that the reader has some familiarity with computer hardware and software, and in particular with the grinding process. The paper is organized into four parts: a general commentary of the need for computer control of grinding, a discussion of the process considerations involved, a more detailed elaboration on the current state of applicable computer technology, and a case study indicating one approach towards such a project. A brief installation survey and references for further reading are also given. This section will primarily deal with supervisory computer applications. Direct Digital Control and microprocessor systems are generally used as replacements for analog controls and thus are not considered in depth. Many configurations of grinding circuits exist, necessitating certain assumptions. Since many new concentrators use an open circuited SAG mill feeding a closed circuit ball mill, this configuration is used as a model although the principles stated can be extrapolated to any circuit. Motivation The use of computers for industrial control has been one of the dreams of control engineers and operators alike for many years. The concept of a plant running at optimal conditions with minimal operator involvement is very attractive from economic and technical standpoints. Accomplishment of this goal has been a long struggle, but today likelihood of success of such a project is very high, considering the reliability of modern hardware and the sophistication of available software. The primary motivation of any control system must be economic, i.e. it must pay for itself and make money for the owner, directly or indirectly. In grinding control the benefits which can be expected include: a) Higher through-put b) More uniform product in particle size, density and volumetric flog: c) Reduced operating costs including media consumption, power consumption and liner wear

Jan 1, 1982

By Emil Gathmann

Steel as it is poured, or teemed, into the mold for forming the ingot may be broadly separated into two divisions; i.e., effervescing or gassy steel, also termed evolution steel, and non-effervescing or killed steel, also termed solution steel. Between these primary divisions there are various types having the characteristics of both divisions but really nut belonging to either; such steels are termed semi-piping, rising, or wild, as the type may be. True effervescing steel should contain large volumes of gases, which are evolved while the metal is being teemed from the ladle nozzle into the mold, and continue to escape while the temperature of the steel is falling prior to its solidification the top of the ingot remaining liquid, due to the evolution of gases, until an ingot skin of considerable thickness has been formed. These gases consist principally of hydrogen, carbon monoxide, nitrogen, and ammonia. It is generally understood that nitrogen gases are the first evolved and these form the skin blowliolcs, troublesome at times, in the solidifying ingot. Ingots made of effervescing steel will always contain a large number of blowholes. Such blowholes are not deemed objectionable in certain products if they occur well inside the ingot where they will not be subjcct to oxidation upon cooling, reheating, and rolling or forging of the ingot. Very little top or bottom discard is taken from this type of ingot, as pipes, or large shrinkage cavities, at the upper portion of the ingot do not usually occur, the difference in volume between the liquid and the solid steel (6 to 10 per cent.) being compensated by the innumerable blowholes distributed throughout the body of the ingot. Of the 40,000,000 tons of steel made in the United States during the year 1919, at least 35,000,000 tons of ingots were made of gassy or semi-gassy steel. Killed, or solution, steel is termed true piping steel from the characteristic pipe or shrinkage cavity that usually occurs in the uppermost central portion of the ingot.

Jan 1, 1922

By Richard Henry Lee

Since the economies in the blast furnace resulting from enriching iron ores are so great, much attention has been paid during the past few years to the various methods of concentrating lean ores, and, as the concentrated ore is usually of extreme fineness, various methods of agglomeration and sintering, of more or less value, have been put into operation. The resulting agglomerated concentrates are generally obtained in the form of briquettes or nodules. The briquettes naturally divide themselves into two classes: (1) those made by the mixture of some binding agent, and then formed into briquettes under great pressure; and (2) those made by sintering the concentrates, the latter either being formed into bricks before exposure to heat or the sintered mass broken into fragments afterward. Of the first class I will not speak, as they are not used on an extensive scale in this country. The second class of briquettes, or those made by sintering, are simply masses of melted or fused silicate and oxide of iron mingled with more or less silicates of aluminum, lime, and magnesia. The fact that the material in a briquette is sintered is proof positive that there are no pores in the material. There are, however, quite a number of holes of greater or less diameter through the gubstance of the briquette. They are not pores in the common acceptance of that term as applied to ores by furnacemen, as the ides of the holes and channels are fused. In reality the material is simply mill cinder. It is practically untouched by the gases in the upper part of the furnace, and the iron has to be reduced by solid carbon in the boshes and hearth. Briquettes sometimes show a little saving in fuel in the furnace over an ore mixture of large lumps, but that saving is made simply because, owing to the numerous holes and channels through the mass, the briquette is practically composed of numerous small or fine lumps, and, as is well known, the finer the

Jan 1, 1914

By Emil Gathmann

Steel as it is poured, or teemed, into the mold for forming the ingot may be broadly separated into two divisions; i.e., effervescing or gassy steel, also termed evolution steel, and non-effervescing or killed steel, also termed solution steel. Between these primary divisions there are various types having the characteristics of both divisions but really nut belonging to either; such steels are termed semi-piping, rising, or wild, as the type may be. True effervescing steel should contain large volumes of gases, which are evolved while the metal is being teemed from the ladle nozzle into the mold, and continue to escape while the temperature of the steel is falling prior to its solidification the top of the ingot remaining liquid, due to the evolution of gases, until an ingot skin of considerable thickness has been formed. These gases consist principally of hydrogen, carbon monoxide, nitrogen, and ammonia. It is generally understood that nitrogen gases are the first evolved and these form the skin blowliolcs, troublesome at times, in the solidifying ingot. Ingots made of effervescing steel will always contain a large number of blowholes. Such blowholes are not deemed objectionable in certain products if they occur well inside the ingot where they will not be subjcct to oxidation upon cooling, reheating, and rolling or forging of the ingot. Very little top or bottom discard is taken from this type of ingot, as pipes, or large shrinkage cavities, at the upper portion of the ingot do not usually occur, the difference in volume between the liquid and the solid steel (6 to 10 per cent.) being compensated by the innumerable blowholes distributed throughout the body of the ingot. Of the 40,000,000 tons of steel made in the United States during the year 1919, at least 35,000,000 tons of ingots were made of gassy or semi-gassy steel. Killed, or solution, steel is termed true piping steel from the characteristic pipe or shrinkage cavity that usually occurs in the uppermost central portion of the ingot.

Jan 1, 1922

By Peter W. Harben

Once considered the dowdy country cousins of the glamorous metallics, industrial minerals are shedding their old image. They are neither common nor easy and their time has come in an age of increasing specialization. Consider that of the 45 or so industrial minerals and rocks listed in [Table 1], almost three-quarters have ten or fewer significant suppliers (i.e., those individual countries contributing 2% or more of total world production); in more than half the cases, 85% of world production is accounted for by only five countries or fewer. Curiously, even materials that appear to be virtually ubiquitous like crushed rock and common salt have significant production vacuums. For example, there is a severe lack of sound aggregates along the US Gulf Coast and common salt production on a large scale is virtually absent in central Africa. These examples all underline the obvious, but acute truism that "The single most important fact about mineral resources is that they are not distributed equally over the world" (Flawn, 1966). Just as significant today is that human resources are not distributed equally over the world, and so arise some interesting commercial incongruities. In certain regions raw materials are plentiful but consumers are not, and without a market a mineral deposit is merely a geological curiosity. Elsewhere, there may be a market but no local raw material supply. For example, despite a huge market there is no or virtually no commercial production of chromite, diamonds, and manganese in the United States and Canada, nor phosphate rock, diamonds, rutile, and zirconium minerals in western Europe. In contrast, Australia with its small domestic market is the world's largest supplier of bauxite, diamonds, ilmenite, natural and synthetic rutile, and zircon; the same is true for South Africa which is a leading producer of chromite, manganese, diamonds, andalusite, ilmenite, rutile, and zircon (Table 2). In the commercial world, Nature's uneven distribution is counterbalanced by deep sea international trade.

Jan 1, 1994

By E du Plessis, M Rowley, M Fallon, F Golenya, R Swanson, I Robertson

"Check sampling programs were undertaken at Barrick Australia Pacific LimitedÆs Lawlers and Plutonic mine sites in Western Australia. The programs identified that the sampling, sample preparation and assaying protocols required modification to ensure acceptable precision (reproducibility) for each gold mineralisation type. These case studies describe the processes used to identify the: inconsistent precision different types of test work programs that were conducted to quantify the appropriateness for each mineralisation type steps used to modify the protocols.The type of test work conducted included: a duplicate series heterogeneity test for particulate gold mineralisation in the Lawlers gold deposit screen fire assay test work on duplicate subsamples for arsenopyrite associated mineralisation at the Plutonic gold deposit.Each test work program required a detailed scope specifying the sample selection criteria, sample preparation and assaying steps. The aim of the test work flow chart design was to ensure the assay precision between the different particle sizes or duplicate sample pairs could be measured and calculated. In the screen fire test work the true grade of the primary sample was calculated and compared against each subsample.A high quality assay laboratory was utilised for the test work. All samples were fire assayed and the gold grade determined using a gravimetric finish. The assay results were validated and the data was analysed using tables and graphs in spreadsheets. Following data analysis a modified sample preparation and assaying protocol for each mineralisation type was designed for use by the principal assay laboratories. Following implementation of the new protocols, routine check samples were collected during the sample preparation and assaying stages to monitor the performance of the new protocol.CITATION:Fallon, M, Rowley, M, Du Plessis, E, Golenya, F, Robertson, I and Swanson, R, 2012. Confirming the sampling, sample preparation and assaying protocols used at two Yilgarn gold deposits, in Proceedings Sampling 2012, pp 47-62 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

By Noah Fields Drake

This paper is devoted chiefly to the coal-fields of the western part of the province of Chili and the eastern part of the province of Shansi; but the outline of this belt will give some idea of the extension of the coal-fields over northeastern China. This part of China is topographically divided into: (1) the mountainous peninsula of eastern Shantung; (2) the coastal plains, extending W. and SW. from the gulf of Pechili; and (3) the mountains and table-lands N. and W. of the coastal plains. The plains extend N. and W. from the gulf to within from 10 to 25 miles of the Great Wall, while their SW. extension covers western Shantung and reaches W. along the Yellow river almost to the southern boundary of Shansi. A line joining the mapped coal-fields, shown in Fig. 1, almost gives the western boundary of the plains; since these areas lie on the border of the plains—except the Tsê Chou field, which is on the table-land, 20 to 25 miles from that border. The coal-fields which have been mapped and investigated by the author are shown in Fig. 1. The one at and around Tongshan is known as the K'ai-p'ing coal-field; the one W. of Peking has been called the Wang-p'ing coal-basin; the one SW. of Pao-ting and N. of Chêng-ting may be called the Lingshan coal-field; and the one at and around Tsê Chou is known as the Tsê Chou coal-field. I. The K'ai-p'ing Coal-Field. As is shown in Fig. 2, most of this field lies in the coastal plains, and is therefore covered by alluvium and loess, which have buried the older rock-beds, and the more gentle and older topographic outlines, to such an extent that most of the re-

Jan 1, 1902

By W. C. Ferguson

"This paper could be more appropriately titled ""The Application of Vacuum Filters to Underground Minewater Treatment. in a previous paper co-authored by the writer (1) the history and development of minewater treatment at the Sudbury District Operations of the International Nickel Company was outlined. It is the intention of this paper to dwell more specifically WIth the the application of the vacuum filter to a problem found in most, if not all, underground mining operations. In the preparation of this paper the writer has made liberal use of the illustrations and text of the paper previously noted.Last year we heard Mr. Nemeth discuss the basic mechanisms involved in vacuum filtration (2), and today Yr. Cunliff has exposed us to the selection of the filter media (3). I will now briefly review the various vacuum filter designs that generally lend themselves to metallurgical dewatering applications.DRUM FILTERSThe revolving drum-type which filters on its outside periphery is illustrated in Fig. 1. This is the Oliver or Drum filter and represents the first commercially available continuous vacuum filter. The original design dates back more than 50 years, but with the exception of the method of discharge, is identical to the units being marketed today. This filter is generally applied to slow filtering slurries. The cake may be discharged in several ways; strings, scraper blades, rolls or by passing the filter cloth over a small diameter discharge roller (belt discharge).THE DORRCO FILTERThe revolving drum type which filters on its inside periphery is illustrated in Fig. 2. Here the slurry lies in the drum and the cake discharges through a chute or conveyor. This type of filter is most often applied to fast-filtering slurries.THE DISC FILTERThe revolving filter which filters on the vertical plane of the disc is referred to as the Disc or American-type filter. This represents the most inexpensive design in terms of cost per square foot of filter area. This filter is widely applied, but is probably more suitable for slower draining pulps."

Jan 1, 1971

By Richard A. Andre, R. Larry Grayson, Thomas Simonyi

"INTRODCICTIONThe search for the cause(s) of coal workers' Pneunoconiosis continues despite the vast amount of research that has been undertaken over the past forty to fifty years. Good correlation between the mass of dust inhaled over workers' lifetimes and the incidence of the disease has led to the development of effective environmental standards and implementation of good procedures for the control of dust generation and dispersion in the working place. Research has only begun, however, to uncover the biochemical mechanisms involved in initiating the disease.Correlation between the rank of the coal seam in which miners worked and disease incidence and severity is acknowledged worldwide, but the agents in the higher rank coal seams which cause CWP arc still not defined. The basic components of the coal seams, i.e., the elements and minerals, are generally known, but the way in which they interact with human pulmonary cells is largely still a mystery.The process of disease development is a biochemical one which depends on the characteristics of the pulmonary cells within their immediate biochemical environment and the characteristics of invading respirable coal mine dust particles, probably both chemical and physical ones. The cell-particle relationship, therefore, must be defined, and both cells and particles must be characterized according to properties which potentially are involved in the disease process.Following such characterization, specific respirable dusts from different coal seams, which appear to have different effects on coal workers, must be obtained or constructed and then used in experiments designed to determine dust toxicity or the response of animals exposed to the dusts.The results presented here focus on characterizing properties of respirable coal mine dust particles collected from operating longwalls in West Virginia and Virginia Longwall panels were selected for analysis because the respirable dust in the coal face areas is largely uncontaminated by rock dust and analysis of the dust yields results unconfounded by rock dust."

Jan 1, 1990

TO THE BOARD OF DIRECTORS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS Gentlemen: - I herewith present a report of some. of the more important activities of the Institute for the year of 1922. The outstanding feature of the year is the optimism felt by our members despite the continued depression in the mining industry. January 1, 1921, found many of our members out of employment or drifting into other industries to tide them over the depression, but almost universally the feeling has been that this was but a temporary condition and that sooner or later the necessary production of raw materials would enable these members to return to their former activities and renew their participation in Institute affairs. As the year passed conditions improved and, before it ended, many had found employment in their previous occupations. Bearing in mind that this depression has been very real, we have reason to be well satisfied with the work that the Institute has been able to do. The loss of members through inability to pay, dues has been large, and income has been correspondingly reduced, but it proved to be materially in excess of that anticipated early in the year, so that a substantial and unanticipated balance was carried forward toward the activities of 1923. PUBLICATIONS Following the example of other technical societies, and to conserve our resources, no Year Book was published in 1922. The lack of an up-to-date membership list for the use of our members was regrettable, but the saving of $5000 proved to be worth while. During the year, Volumes LXV, LXVI, and LXVII were printed and sent to members. These volumes were composed largely of the papers of 1920 and 1921, publication of which had been delayed partly through lack of funds and partly for the purpose of segregating into volumes those papers dealing with the same general subject. The segregation of papers had been suggested by a number of members who had advised that they were not primarily interested in all subjects

Jan 1, 1925

By Julian Avery

IN its dual role of pig-iron smelter and gas producer, the blast furnace is a remarkably satisfactory and efficient apparatus. Many metallurgists and engineers have pointed out, however, that since the primary function of the blast furnace is to produce pig iron at the lowest possible cost, its function as a gas producer should be subordinated to this primary pur-pose. During the past 10 years or more, improvements in blast-furnace technique and economy have, in fact, been directed primarily to increasing efficiency in the use of the reducing power of the gases produced by com-bustion of coke at the tuyeres, to reduce iron ore within the furnace. The net over-all result is a decrease in the fuel value of the top gas per unit of volume, and per ton of pig iron, which is evidently more than offset in value by the corollary saving in coke and the possibility of increased furnace capacity, for otherwise there would be no point in making such improvements. The purpose of the present paper is to suggest that, while progress has been made in this direction, there is another approach to the problem of increasing the chemical and thermal efficiency of the blast furnace in its primary role as a pig-iron smelter, which appears to offer possibilities of improvement in over-all economy of a different order of magnitude than results thus far obtained by the use of other expedients. The present argument is based in large part upon the hypothesis that the effi-ciency and economics of pig-iron smelting are seriously and adversely affected by the phenomenon known as "solution loss," and that the problem of solution loss can be successfully attacked by increasing the over-all pressure; i.e., the "top pressure" under which the furnace is operated. It is indicated that pressure operation may also be expected to result in concomitant benefits, which may be summed up as generally improved operating conditions, together with a substantial saving in fuel and/or a substantial increase in furnace capacity.

Jan 1, 1938

By Sidney Powers

SINCE the opening of the Wheeler oil and gas field in Carter County and the discovery of oil near Lawton, Comanche County, Okla., in 1904, interest has been aroused regarding the origin of the oil in the Permian "Red Bed" region which lies between the Wichita and Arbuckle Mountains on the north and the Red River on. the south. . The later development of the Healdton, Loco, Duncan, Fox, and Graham fields south and west of the Arbuckle Mountains has brought the region into prominence. Recent discoveries of Ordovician and of Pennsylvanian fossils in wells in the Healdton field and of Pennsylvanian fossils in the Fox and Graham fields are of such importance from a scientific and a commercial standpoint that the occurrences and the problems arising therefrom are here briefly described. Producing oil and gas sands in the southern Oklahoma fields, with the exception -of those in the Cretaceous and underlying rocks in the vicinity of Madill, Marshall. County, are associated with the Permian "Red Beds" or with the underlying Paleozoic strata. I n the two fields farthest south of the Arbuckle Mountains, Healdton and Loco, production has been entirely confined to sands at depths of 700 to 1400 ft. (213 to 416 m.) and only recently has a producing sand as deep as 1860. ft. (567 m.) L been encountered. These sands are found near and below the base of the red rocks and were supposed by Wegemann and Heald 2 to belong in large part to the basal Permian,. Wichita formation, or to the immediately underlying formations. Fossils in the blue shales and in the limestones associated with the deeper sands' now prove them to be Pennsylvanian and all-the producing sands at Healdton are found to be of this age. In the fields nearest the Arbuckle Mountains, the Wheeler sands at a depth of about 700 ft. (213 m.) appear to be of Permian age,

Jan 11, 1917

By A. E. Harnsberger

I is obvious that details such as the physical and chemical properties and methods of heat-treating of the materials mentioned must be omitted in a paper on the subject of materials used in oil-refinery pumps1. Only sufficient identification is given to enable the reader to find additional information from already published data. Also, the subject covers many operating conditions, but only the most important services can be discussed here. To the oil refiner, the pumping equipment is of vital interest. Practically every refinery operation, from the charging of crude oil to a distillation unit to the shipping of refined products, involves some form of pumping machinery. Intermediate refining stages involve a great variety of pumping machinery to carry out successfully the aims of the refinery technologist. Temperatures at which oils are handled vary from — 50" F. to 900" F. Pressure may vary from subatmospheric to 2000 1b. per sq. inch. The selection of the proper materials involves a careful consideration of the conditions under which the particular pump must operate. The four most important considerations are temperature, pressure, corrosion, and abrasion or wear. Consideration of temperature may be divided into three parts: (1) extremely low temperatures of the order of —50" F.; (2) temperatures at atmospheric or slightly above; (3) temperatures from 200" to 900" F. Pressures fall into two groups: (1) pressures reached by ordinary trade pumps of the order of 200 lb. per sq. in., (2) extreme pressure conditions involving pressures as high as 2000 lb. Noncorrosive and corrosive oils can be treated differently. Under the latter falls corrosion in the presence of water, which will occur up to 250" F. The second type of corrosion occurs in high-temperature pumping equipment, with temperatures from 450" to 900" F., largely caused by sulfur compounds. There are also other corrosive conditions met with in refinery operations, particularly in the handling of acids, acid sludges and other specialized processes. These problems, although difficult to

Jan 1, 1935

By A. E. Harnsberger

I is obvious that details such as the physical and chemical properties and methods of heat-treating of the materials mentioned must be omitted in a paper on the subject of materials used in oil-refinery pumps1. Only sufficient identification is given to enable the reader to find additional information from already published data. Also, the subject covers many operating conditions, but only the most important services can be discussed here. To the oil refiner, the pumping equipment is of vital interest. Practically every refinery operation, from the charging of crude oil to a distillation unit to the shipping of refined products, involves some form of pumping machinery. Intermediate refining stages involve a great variety of pumping machinery to carry out successfully the aims of the refinery technologist. Temperatures at which oils are handled vary from — 50" F. to 900" F. Pressure may vary from subatmospheric to 2000 1b. per sq. inch. The selection of the proper materials involves a careful consideration of the conditions under which the particular pump must operate. The four most important considerations are temperature, pressure, corrosion, and abrasion or wear. Consideration of temperature may be divided into three parts: (1) extremely low temperatures of the order of —50" F.; (2) temperatures at atmospheric or slightly above; (3) temperatures from 200" to 900" F. Pressures fall into two groups: (1) pressures reached by ordinary trade pumps of the order of 200 lb. per sq. in., (2) extreme pressure conditions involving pressures as high as 2000 lb. Noncorrosive and corrosive oils can be treated differently. Under the latter falls corrosion in the presence of water, which will occur up to 250" F. The second type of corrosion occurs in high-temperature pumping equipment, with temperatures from 450" to 900" F., largely caused by sulfur compounds. There are also other corrosive conditions met with in refinery operations, particularly in the handling of acids, acid sludges and other specialized processes. These problems, although difficult to

Jan 1, 1935