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By W. H. Newhouse

During the past few years the writer has been impressed by the close relation of many epigenetic orebodies with anticlinal structures. In the literature on ore deposits there is occasional mention that an oreshoot or district is on an anticline, but in most of the descriptions no weight or significance is attached to the relation, and usually the fact is concealed in a mass of structural detail. A few writers have stressed the relationship in a few districts or on a certain type of deposit. Church, Spurr, Butler, Stahl and Schuette have called attention to certain features, but the general extent of such a correlation has not been made known in any publication that the author has seen. A recent article1 on the localization of ore deposits, by well-known geologists, does not consider this common association. The author has seen in the field a number of the structural features described, and in addition has made a fairly complete review of the literature. This paper presents enough of the examples found to show the frequency of the relation to anticlines, and since only a few deposits on synclines are known, all of these of any importance of which the writer knows are mentioned. With certain qualifications which are discussed later, epigenetic ore deposits of replacement or vein type are mostly found where local upwarps of the earth's crust have taken place. Where formations antedating the ore deposits are present in the proper attitude to demonstrate vertical warping (i. e., more or less horizontal beds) the structural feature on which a mineral district, or mineralized area is located is almost always anticlinal, or domelike in nature. Some or even most of the ore deposits in a given district may be on the flanks of the upwarp, but few major districts are located definitely on downwarped areas. Synclinal basins within certain limits of size appear to be unfavorable to the type of fracturing that admits ore-bearing solutions. Replacement orebodies frequently are localized in small anticlines or domes, the size of the anticline or roll often being more or less commensurate with that of the enclosed oreshoot. This feature certainly ranks

Jan 1, 1931

By Albert Hahn

ABOUT three years ago John Hays Hammond took over the control of the Eureka Metallurgical Co., at Salt Lake City, Utah. Funds were advanced for investigating the process invented by R. V. Smith, for concentrating oxidized lead ores. A great deal of laboratory work was done and a reagent was developed by C. M. Nokes of Salt Lake, which was found to be particularly suitable for oxidized copper ores, refractory manganese silver ores, and oxidized gold ores. After sufficient laboratory work had been performed to demonstrate the fundamental principles of these inventions, a test mill, having a capacity, of 20 tons of ore daily, was erected at Murray, Utah. In this test mill approximately 1200 tons of various types of ores have been concentrated by means of the above-mentioned process and reagents, and this large-scale work as well as laboratory work is being continued at present. Details of these mill tests are given in Table 1, and a representative group of laboratory tests are shown in Table 2. The process requires no special machinery or appara-tus. Its success depends entirely, on the method of preparing the pulp and its subsequent flotation in clean water, as outlined in the Smith patent. The reasons for the success of the Nokes special reagent are not definitely known. The outstanding feature, which seems to be of extreme importance, is that when the concentrates are examined under the microscope, each particle of mineral appears to have a particle of paraffin, attached to it. This paraffin-mineral combination seems to be particularly suitable for flotation and it follows that any coating oils readily attach themselves to the paraffin-mineral combination.

Jan 9, 1923

By G. G. Sarkar

SHARPNESS of separation and washing efficiency are often confused. The sharpness index indicates the precision of a washing unit; the washing efficiency takes into account not only the unit's precision but also the washability characteristics of raw coal and the near-gravity materials at the effective density of cut. A sound basis for evaluating the sharpness index is essential in comparing the sharpness of separation attained by different cleaning units. Sharpness Index and Related Criteria: Washing plant sharpness of separation has been well represented by Hancock's efficiency chart and Tromp's curve of migrated materials. Some useful coefficients derived from Tromp's curve-the error area, probable error, and imperfection value-have been widely used to measure sharpness of separation. These are defined in a number of papers presented at the first and second International Coal Preparation Conference held in Paris (1950) and Essen (1954).1-5 In evaluating the performance of a dense medium separator at four different gravities, Yancey and Greer6 observed that even with similar operating conditions and the same size grading of feed, the imperfection value of a washing plant varies through a greater range than the probable error. The present writer also observed the same type of anomalies in comparing the imperfection values of one plant which were determined under almost identical conditions. He therefore devised a graphical method to evaluate a washing unit's sharpness of separation and define it by a single coefficient, which is substantially independent of coal characteristics under normal operation of the unit. Unlike imperfection value, the new coefficient can be expressed on a percentage basis.

Jan 12, 1957

By T. A. Rickard

From time immemorial the fissure-vein has been held the simplest type of ore-deposit. The prominence given to it by Cotta and his disciples, from their study of the mines of the Erzgebirge, is impressed upon technical literature; and, in consequence, the ores which carry the valuable metals have been supposed to occur mainly in fissures, cleaving the rocks in diverse directions, and the noblest type of vein has been deemed that which cut across the country independent of its structure, whether evidenced as bedding, foliation or cleavage, and which was identified with rents produced in the rocky crust of the earth. As so conceived, the vein was a fissure filled with ore, extending through the country for a varying distance, and continued downward to a depth more or less proportionate to its longitudinal extent. The vein-material was bounded by an encasement of rock, and those immediate surfaces which limited it on either aide were called " walls." These primary conceptions have become modified by the experience of modern mining in widely separated regions. The study of lode-formations has led to the recognition of notable departures from the supposed normal structure of the veins of Saxony and Cornwall, the two classic homes of early economic geology. Typically the walls of a vein are conceived as parallel rockplanes enclosing the ore; the upper one being called the " hanging-," and the lower the "foot-wall."* Walls are rarely alike. Even where a vein traverses a homogeneons formation, such as a massive crystalline rock, it is usually found that the surface which bounds it underneath

Jan 1, 1897

Diversity is a key strength for Western Mining Corporation. An international corporation with assets of about $A10 billion, WMC is engaged in both mining and downstream processing of minerals including nickel, gold, alumina, copper and talc, as well as having interests in oil and gas production and agricultural fertiliser. The company is focusing on several core commodities that will maintain its strength in the years ahead. Although most current mineral assets are within Australia, it plans to have 25 per cent of its operations off-shore by the turn of the century, and be a major producer in at least six core commodities. WMC's strategic and management focus has shifted from a regional approach to a commodity focus so that it can more readily cater for different markets with differing sensitivities. This document is an ABSTRACT ONLY - no paper was published for this presentation

Jan 1, 1996

The purpose of this paper is to discuss briefly the problems encountered in designing and sinking No 7 shaft, and to present the methods employed in the operation.The illustrations accompanying the paper show the details of the construction of the equipment used in completing No 7 shaft, consequently the descriptions appearing in the text are brief outlines only. Mineral leases Nos 7 and 8, held by the Broken Hill South Limited, comprise an area of 69.5 acres. The length of the holding is approximately 2500 ft.The western orebodies, which are the main producing masses, enter the property at the northern bonndary. Generally, the dip of the orebody is to the west, and the pitch to the south, but local variations occur and even a reversal of pitch has been noticed. The angle of dip is approximately 70 degrees and the angle of pitch 45 degrees.

Jan 1, 1932

The earliest record of coal in Indiana is one of the earliest in the country. At the close of the French and Indian War, in 1763, the famous Indian trader, George Croghan, was sent from Pittsburgh on a mission to the western Indians. His party met that of a hostile chief on the lower Ohio and was captured, and were taken up the Wabash River; on June 22nd, he passed the mouth of the Vermilion River-probably the Big Vermilion-and on June 23rd, he made the following entry in his journal: "on the South Side of the Ouabache runs a high hank, in which are several very fine coal mines, and behind this bank, is a very large meadow, clear for several miles."' The mines, of course, were outcrops. A few days after this he met some Indian acquaintances who secured his freedom. This location was at Ouicatanon, 210 miles from "Port Vincent," which was destroyed a few years later, and in what is now Fountain County, probably near Coal Creek. Croghan was familiar with the coal already being worked at Pittsburgh. Surveyors who ran the township and section lines in the first ten years of the last century noted the presence of coal and marked its position on the maps in 1804.2 The next record is by Nicholas J. Roosevelt, who in 1809 examined the Ohio and Mississippi Rivers prior to starting building the first steamboat to navigate these rivers. "Not only did he do this, but finding coal on the banks of the Ohio, he purchased and opened mines of the mineral; and so confident was he of the success of the project on hand, that he caused supplies of the fuel to be heaped upon the shore, in anticipation of the wants of a steamboat whose keel had yet to be laid."3 It is probable that this account confused the date of seeing the coal with that of mining it, as an earlier account by another relative of Mrs. Roosevelt of the first trip of the steamboat New Orleans in 1811 is as follows:

Jan 1, 1942

By H. F. Moore

AT PRESENT, I am connected with an investigation of the so-called fatigue of metals under stress. So far we have studied the more fundamental and simple case of the repeated stress, without the additional complexity of impact, which might bring in other factors. We feel that this investigation, which has been in active progress for a little over a year, has shown more conclusively than has been shown before that steel under repeated applications of stress, reversed from positive to negative, will not fail below some fairly clearly defined limiting stress that,, so far we can see, does not bear any definite relation to the ordinary elastic limit, being as large as the elastic limit in some cases and about one-half the elastic limit in others. I might be asked, first, what is fatigue. The old view is summed up "in the word "crystallization." The idea was that under repeated stress the material changed its crystalline structure. I do not know of any evidence in favor of the theory that metals materially change their crystalline structure under repeated stress. The crystals are broken under repeated stress. The second theory, advanced by Bauschinger, the German scientist, is that under repeated stress some inherent property of the material changes its elastic limit; it is an inherent property of the material, possibly some property of the amorphous cement between the crystal. The third view is that all fatigue of metals is the result of the spread of damage from little localized overstresses. I do not feel justified in stating my positive belief in the third view as against the second, but I have yet to run across a case of failure of steel or other metal, either in the laboratory or in service, that could not be explained by the gradual spread of damage from some nucleus. We have found, for example, that it is possible to subject a homogeneous steel, like Armco iron or a 0.90 per cent. carbon steel, that hag been thoroughly annealed, to one hundred million reversals f stress as high as the elastic limit of the steel with no sign of failure. We stopped the test at one hundred million because the machines Were required for other work. Forty-five days, continuous running at 1500 revolutions a minute is required to produce one hundred million repetitions. On the other hand, a complex structured steel, like a chrome-nickel steel that

Jan 6, 1921

By E. C. W. Perryman

IN spite of the large amount of work which has been carried out on the recrystallization of aluminum and its alloys, there has been no complete investigation of the recrystallization characteristics of A1-Mg alloys. The most complete investigation is that reported by Bungardt and Osswald' who, working with commercial-purity materials, found that the temperature both of beginning and of complete recrystallization increased with magnesium content up to about 2 pct Mg, then decreased with a further increase in magnesium up to 5.0 pct, and thereafter increased again. Michaud and Segolz working with 99.93 pct A1 also found the temperature of beginning of recrystallization to decrease as the magnesium content increased from 2.13 pct to about 4.5 pct. Chossat3 using aluminum of 99.99 pct purity found that 0.12 pct Mg had no effect but that 0.4 pct Mg increased the recrystallization temperature by about 30°C. That no effect was found for 0.12 pct Mg does not agree with the later results reported by Demer and Beck4 who found that 0.025 pct Mg in 99.99 pct A1 increased the time for complete recrystallization and furthermore increased the activation energy for the recrystallization process. Kratz" using 99.997 pct A1 found that 0.5 pct Mg increased both the temperature of beginning and of complete recrystallization by 100°C. Chadwick and Hooper" working with commercial-purity material found that 1 pct Mg increased the temperature of complete recrystallization by about 40 °C for cold reductions in the range 17 to 72 pct. With smaller amounts of cold work produced by stretching (10 pct strain), they found no significant effect of magnesium. The latter result agrees with that obtained by Williams and Eborall' who found no effect of 2 pct Mg on the recrystallization temperature of commercial-purity aluminum strained 10 pct or less by stretching. Experimental Procedure Material Used: The chemical analyses of the materials used throughout this investigation are given in Table I. Fabrication: The alloys were cast in iron molds which had been washed thoroughly with alumina. After scalping, the ingots were annealed for 16 hr at 450°C, pressed, annealed at 450°C for 16 hr and hot rolled to 0.25 in. After hot rolling, the slabs were alternately annealed and cold rolled to 0.036 in. Cold-rolling reductions between intermediate anneals were kept at about 30 pct and a high intermediate annealing temperature of 450°C was used so as to obtain, as nearly as possible, similar starting grain sizes for the different materials. All intermediate anneals were done in a salt bath and were followed by cold-water quenching so as to retain all the magnesium in solid solution. The final cold reductions investigated were 20, 30, 40, 50, 60, and 80 pct. The initial grain sizes, that is, the grain size before the final cold reduction, were all very similar. Annealing Procedure: Specimens, 1 in. sq, were cut from the 0.036 in. sheet and annealed in a salt bath, the temperature of which was controlled to k2"C. Separate specimens were annealed for different times at 350°, 375", 400°, and in one or two cases at 415°C and after annealing were quenched in cold water. The time taken for a specimen to reach temperature was approximately 5 sec. Metal-lographic examination after annealing showed that no precipitation of Mg+413 occurred during cooling. Procedures Used for Determining Recrystallization Characteristics: All specimens were electrolyti-cally polished and etched by the method described previously1° and polishing was continued until about 0.002 in. had been removed from each side of the specimen. Using this technique, the smallest recrys-tallized grain which could be observed with cer-

Jan 1, 1956

At the meeting of the Board of Directors of this Institute on Feb. 16, 1915, the 14 members of the Board present unanimously elected Professor Kemp an Honorary Member. The nomination of Professor Kemp was signed by 21 members of the Institute, none of whom are members of the Board of Directors, and recited his qualifications for Honorary Membership in the following terms: Professor Kemp graduated from Amherst College in the class of 1881, and from the School of Mines, Columbia University, in the class of 1884. After serving as instructor in geology in Cornell University for a few years he was called back to Columbia as adjunct professor in 1891, was made full professor the following year, and has since filled that office with dignity and honor. Among the first to recognize they importance of igneous rocks in the formation of orebodies, his studies have contributed greatly to that increase of knowledge of economic geology in which the Transactions of the Institute has had an influential part, and he is recognized both abroad and in this country as one of the most distinguished scholars in geology which America has produced. This recognition is evident in the honorary degrees of Sc. D. conferred on him by Amherst College in 1906, and LL. D. conferred by McGill University in 1913, as well as by election to membership in the National Academy of Sciences, and a corresponding member of the Academy of Sciences of. Christiania, and the Geological Society of. Stockholm. Professor Kemp was a Manager of the American Institute of Mining Engineers from 1896 to 1898, Vice-President from 1903 to 1904, a Director from 1905 to 1912, President and President of the Board of Directors in 1912, and Past President since that time. During these years he has labored loyally for the upbuilding of the Institute, serving on many committees, as well as in the offices enumerated. He has also served as President of the American Association for the Advancement of Science, the New York Academy of Sciences, and on the governing board of the Geological Society of America and the New York Botanical Gardens. His service is not confined, however, to these labors for the good of the profession and his contributions to exact knowledge of geology. In his almost 25 years as a professor in Columbia University there have come under his influence a great group of young men in whom he has inspired unflagging zeal in the search for truth, and to whom he has set an example of unselfish service. The value of such a service cannot be overestimated and in electing him to Honorary Membership the Institute would officially recognize the measure of appreciation which his professional colleagues have long accorded to him.

Jan 4, 1915

By B. Talbot

How this simple plant generates a large revenue stream. The concept behind the Tailings Scavenging Plant (TSP) is simple: it is a non-complicated modular plant which is designed to be more stable than upstream plants. This, plus the use of ?high energy?, enables the plant to recover any metal missed by the upstream operation. Impala Platinum?Mineral process started pilot plant exercises in June 2003. The pilot plant ran for one year before the capital for the full-scale plant was approved. This year was used to motivate, design and cost a full-scale plant. The metal produced during the pilot and feasibility study enabled this part of the project to run at a small profit. The scale-up to full-scale was relatively simple as the pilot plant had a capacity of 180 m3/hrand the full-scale plant was designed for a capacity of 550 m3/h. The design for the full scale plant was completed in May 2003, with ground breaking taking place on 19 May 2003. The construction phase of the project went well with the commissioning of the first two modules taking place on 22 October 2003. The remaining two modules were commissioned two weeks later. The plant was at full capacity by the 20 November 2003. A review of the plants performance for the first 5 production months is as follows: the plant has required only a few minor modifications and additions, it has run well in excess of 95%availability with no major wear apparent. In addition to this, the plant has produced 3 times the metal forecast.

Jan 1, 2004

By Lyman Fearn

Men and institutions are what they are largely because of inheritance. Out of the past comes experience that enables men to build more wisely than did preceding generations. The field of possibilities has widened as the horizon of men's vision has been extended. The realization of these possibilities has depended largely on the application of men's natural endowments, brain and brawn, to the problems at hand. In the field of mechanized mining, Wyoming has a greater percentage of men with vision, who have a realization of the possibilities of mechanized mining, than any other state in proportion to tonnage production. With the introduction of mechanized mining systems have come problems that have caused the men who are connected with the safety work much thought. Discussions on mechanical drilling, cutting, loading, conveying, haulage, etc., have come in for their share of the debate. There have been a few attempts made to show that mechanical mining is safer than are the more primitive ways of doing underground work by man power. We also have a number of places in the coal producing States of the United States, where the mechanized systems have been abandoned chiefly on account of the safety element involved bringing about condemnation of the system by State inspection forces. Certain types of scraper systems have been condemned, and some have voiced opposition to long faces. This would lead us to believe that the question is still a debatable one as far as the safety element is concerned. It is only fair that we discuss the operations of mechanical systems and from the results obtained take analysis of conditions as they exist, basing our conclusions from the results obtained.

Jan 1, 1928

By Virgil Miller, F. B. Petermann, S. F. Ravitz

The Cle Elum nickeliferous iron deposit is in Kittitas County, Washington, in a rugged, mountainous region about 23 miles north of the town of Cle Elum. The Biewett Pass deposit, which is similar in character and occurrence, is in Chelan County, about 18 miles east of the Cle Elum deposit. A more or less continuous ore zone may extend between the two deposits, since iron ore is reported to have been discovered at Iron Mountain, which lies directly between them. The ore probably was formed by meta-morphism of laterite resulting from Ieach-ing of serpentine derived from peridotite. It consists largely of magnetite grains distributed through a matrix of limonitic material containing a small amount of hematite and chromite. Many of the chromite grains have shells and inclusions of magnetite. The magnetite grains range in size from 1200-mesh to 1/4-in., the average size being 48 to 65-mesh; the chromite grains range from 20 to 150-mesh. The gangue minerals are olivine and serpentine with a small, amount of chlorite, and appear both as very thin bands in the ore and 's minute fragments in the limonitic matrix. The nickel is present as minUte inclusions of a nickel silicate mineral within the magnetite and gangue par- ticles, varying in size from 1500 to about 280-mesh. Detailed analyses of 3000-lb. lots of Cle Elum and Blewett Pass ore are given in Table I. TABLE i.—Analyses of Ore Samples Per Cent Ore from Constituent cle Elum' Blewett Pass Cr....................... 2.23 2-12 Ni...................... 1.43 0.9s Fe...................... 52.9 41.4 SiOz.................... 5.6 13.4 CaO.................... 0.3 0.8 MgO................... 4-1 7-5 AI2O3................... 7.0 2.g P...................... 0.022 0.034 S....................... O.O1 o.oa Mn..................... I.I 0.4 Ba..................... nil co..................... o.oa 0.02 CU..................... 0.02 0.03 As...................... 0.03 Au..................... nil Ag°..................... O.58 Pt...................... ml Fe++.................... 8.9 5-9 Fe+++.................. 44-0 35-5 « Ounces per ton, 1 sr,cte,so,","&&$ally absent: B, W, M~, T~, V, ~i, Bi, Pb. Sb. Sn. Be, In, Hg. Zn, Zr. Cd. Preliminary Tests Attempts to beneficiate the ore by ore-dressing methods, including various 'cornbinations of sink and float, tabling, jigging, flotation, and magnetic separation, were consistently unsuccessful. A wide variety of roasting and leaching tests were made on both raw and reduced ore, but in most of the tests little or no nickel was extracted, and in none did the extraction exceed 50 Per cent. No nickel could be volatilized as the carbonyl. by treating reduced ore with carbon monoxide. Fairly good sepa-

Jan 1, 1944

By G. Heinrich

Size by size recoveries and pentlandite liberation data from image analysis were used to evaluate plant tests of pentlandite flotation and pentlandite/pyrrhotite middlings flotation from pyrrhotite in a circuit treating low grade magnetic intermediates at the Strathcona Mill. Raising the pH with lime gave improved selectivity for liberated pentlandite but there were major losses of middlings unless the circuit was pulled hard indicating the need for finer regrinding. However, size by size recoveries at the normal regrind showed that, while the pentlandite recovery improved in the finer ranges, the pyrrhotite recovery also increased leading to little selectivity in any size range. A much finer regrind gave greatly improved selectivity in all size classes suggesting that 'surface polishing' as well as liberation effects were being seen. Using liberation data from image analysis of the products, surface polishing accounted for over 99 % of the improvement in selectivity. Unreasonable recoveries of more highly liberated particles were observed for liberation analysis by volume fraction but showed the expected trend in recovery when the analysis was based on surface liberation. The surface liberation data showed that the improved pentlandite recoveries after finer regrinding were to more than 90 % caused by improved liberation with the remainder contributed by surface polishing effects. The practical implications of this work are that i) the comparison of particle grades with product grades allows to estimate the effect of regrinding on co-flotation/entrainment, ii) surface liberation models should be used for evaluating recoverabilities by flotation and iii) regrind circuits may be set up to ensure that all particles go through the mill or that only the coarse fraction is reground depending on the surface scrubbing found to be required.

Jan 1, 1993

By K. Mulukhov

Introduction The depth of open-pit mines continues to increase. The typical designed depth for large quarries is now in the 300 to 600 m (1,000 to 2,000 ft) range, with some quarries even reaching depths of 700 to 800 m (2,300 to 2,600 ft). The cost of handling material from such deep mines can be 60% to 70% of the total cost. The capacity of using a cyclic means of transport, such as trucks or skip hoists, continues to drop as the depth of the mine increases. In addition to the problem of maintaining relatively low slope angles for haul roads, increases in environment pollution and increased fuel consumption make the use of trucks ineffective below 100 to 150 m (300 to 500 ft). In handling large quantities of bulky materials, i.e., more than 15 to 20 Mt/a (16 to 22 million stpy), under fixed terminal points, belt conveyors are preferable in almost in all cases. An exception is when the lump size of the load is too high for the conveyor to handle. Belt conveyors in mines can handle loads having a maximum lump size of no more than 250 to 300 mm (10 to 12 in.). The use of a movable crusher prior to the belt conveyor in an open-pit mine would make the process very expensive. Such an operation could not compete with truck haulage on a cost basis. Belt-car conveyor The main factor that restricts the lump size for conventional belt conveyors is collision impacts between the load-carrying belt and idlers. These impacts are completely eliminated in the belt-car conveyor, which was previously described by Mulukhov (1977). The unique feature of the conveyor is that the load-carrying belt is supported by moving cars. Each car consists of a troughed cross strap that supports the belt with the load and two rollers, on which the cars move along upper and lower rails. Cars are connected by two endless chains revolving over sprockets. The system uses conventional drive pulleys, tail pulleys and return idlers. There are no fasteners between the carrying belt and the car cross straps. The conveyor belt simply drives the cars along by the force of friction between the belt and the straps. A belt-car conveyor was first installed in 1970 at the Karatau mining operation in Kazakhstan. The system was an elevating conveyor with an inclination of 20° and was located on the final part of the truck haul road. The conveyor transferred blasting phosphate ore from the quarry to the crushing plant. A bunker was mounted between the trucks and the conveyor. The maximum lump size was typically 1,200 mm (48 in.). However, there were some lumps as large as 1,500mm (60 in.), which was greater than even the belt width (Fig. 1). Because the prototype belt-car conveyor was intended only for industrial trails, it had a relatively short length of about 50 m (160 ft). Nevertheless, the conveyor yielded a substantial profit over the cost of truck haulage. Naturally, the first question one might ask is why such a system is not now widely used. The reason was the further development of a huge transporting complex for the whole quarry at the base of the belt-car conveyor. After successful industrial trials from 1971 through 1973, which demonstrated the systems engineering feasibility, the State Planning Committee of the USSR included the development of the belt-car conveyor in its plan for the development of the national economy. However, mistakes were made. First, a single organization was not in charge of the development. Second, a plant that was not specialized in belt conveyors was put in charge of the design and manufacturing of the conveyor system. In addition, the crusher was installed before the stacker, which negated the major advantages of the belt-car conveyor. For loading the conveyor, a special blade feeder with pendulum suspension was developed, but it was found unreliable. The main conclusion was that, in-

Jan 1, 2003

By W. E. C. Eustis

1st. THE fine iron ore is mixed with a sufficient proportion of fine coking coal, and is coked in any of the ordinary methods for making coke. The effect of this is to convert the iron oxide into sponge in such a shape that the usual trouble of oxidation is avoided. 2d. The resulting mixture of coke and sponge is melted down in an ordinary cupola, the coke furnishing more than sufficient fuel for that purpose. I may briefly point out here that in the first place the iron is sponged, and this sponge, as is well known, contain-, no phosphorus or silicon when the reduction takes place at a low temperature; and in the second place this sponge is melted down in a cupola in which there is no zone of reduction for phosphorus or silicon, and that con¬sequently the resulting iron should be free from both of these impu¬rities. 3d. The liquid sponge, now carburized, is run into an open-hearth furnace, where the requisite degree of hardness or softness is obtained by adding some of the fine ore, and the usual dose of ferronmanganose. I have merely given above the rough outlines of the process, but it is my intention, as early as possible, to bring the process more fully before the Institute.

Jan 1, 1881

By M S. Sandhu

Singrauli area of Madhya Pradesh in India has been developed as the power capital expected to produce around 11000 MW in near future requiring 65 million tonnes of Coal per annum. Thermal power plants were installed considering the vicinity of coal reserves which are minable by open cast mining methods. Crisis of oil in seventies further expedited the process of planning big open-cast projects in the area varying from capacity of 3 million tonnes of coal to 14 million tonnes per annum. A separate company - Northern Coalfields Ltd. was formed to ensure meeting the rising demand of coal required for energy production. Northern Coalfields at present is producing 35 million tonnes of coal and will reach the capacity of peak demand of 65 million tonnes by the turn of the century.

Jan 1, 1998

By Joseph J. Poveromo

The blast furnace today continues as the primary production method of hot metal in large-scale steel production. The blast furnace process has been the target of repeated attempts to replace it with various process options, including direct reduction and coke-free smelting reduction. While these new technologies are being adopted in appropriate niches, the blast furnace has responded to the challenge by being amenable to continuous improvement. I will review the role of the blast furnace, major developmental and improvement trends, and then list the current important issues in ironmaking. I will outline the challenges to be faced by the blast furnace to maintain its position as the primary hot metal production process. The material presented here is an update of earlier presentations made in Stockholm, Sweden, 1996, Duluth, 1998 and Chicago, 2000.

May 1, 2003

The authors are looking at the behaviour of the mineral processing circuits by means of the simulators operating under random disturbance. The present paper deals with the fuzzy control systems in comparison with PID controllers. A series of tests are conducted on simplified prototype processes with (1) dead time plus first-order lag model and (2) diffusive model. In the next series of tests the self-sustained process model was introduced to improve control against dead time. In both cases fuzzy and PID controllers are optimised by EVOP method. Particular attention is paid to the effect of observation noise to analyse for the problems which can be fatal to practical applications in mineral processing. Finally the methods developed are applied to a closed-circuit wet grinding system simulator operating under random disturbance.

Jan 1, 1993

By A. B. Parsons

This YEAR BOOK, which is sent to every member, contains the roster of officers and the principal standing committees, brief summaries of the proceedings of the Annual Meeting and of the Regional and Divisional meetings, and the necrology for the year 1934. Also are included abstracts of papers published during the year and a classified list of TECHNICAL PUBLICATIONS and CONTRIBUTIONS, as well as an index of all material published by the Institute in 1934 in TRANSACTIONS, in TECHNICAL PUBLICATIONS and CONTRIBGTIONS and in MINING AND METALLURGY, the monthly magazine, the twelve issues' of which contained 98 technical papers Thus 111 small space are gathered together references to all papers, magazines and books printed by the Institute during the year. The papers for the Iron and Steel and Institute of Metals Divisions have been issued as TECHNICAL PUBLICATIONS distributed under the binding of METALS TECHNOLOGY in the months of January, February, April, June, August, September, October, December This plan of distribution will be continued in 1935 for these two groups The publications for the year 1934 include two sponsored by the Institute's special funds. A Manual for Student Associates and Affiliated Student Societies, prepared by the Committee on Student Relations, of which Jay A. Carpenter was Chairman, was published through the courtesy of the Seeley W. Mudd Memorial Fund, and Volume 112 of the TRANSACTIONS, on Milling Methods, assembled by the Committee on Milling Methods, of which Charles E. Locke was Chairman, was financed by the Rocky Mountain Fund The remaining volumes were all TRANSACTIONS, Volumes 107, Petroleum Development and Technology; 108, Coal Division; 109, Metal Mining and Nonmetallic Minerals; 110, Geophysical Prospecting; 111, Institute of Metals Division and 113, Iron and Steel Division

Jan 1, 1935