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DETAILED programs for the Regional Meeting to be held at Boston, on Aug. 29, 30, 31, will be available on arrival at the Copley-Plaza Hotel, where registration will begin at 10 a. m. on Wednesday morning. The opening session will be non-technical in character and will be called to order at 11 a. m. Hector J. Hughes, Dean of the Graduate School of Engineering of Harvard University, and others will speak, and in the afternoon visits are to be made both to Harvard and Massachusetts Institute of Technology. Wednesday afternoon will be devoted mainly to the opening of an exhibit of geophysical instruments and methods at Tech. On the way back to the hotel a tour of Old Boston will permit the visitors to see many of the historic points of the city. A special meeting of the Board of Directors has been called to be preceded by the usual subscription dinner at the University Club at 6.30 p. m. Owing to limita-tions of room, invitations have been sent only to the usual list designated in the By-Laws, the Directors, past officers, chairmen of sections and of technical committees. The dinner and a brief business session of the Board will be followed by a technical session at the Copley-Plaza at 8 p. m. and this in turn by a buffet supper at the University Club at 10 p. m. Sep-arate entertainment is being provided for the women for the evening. Thursday will be devoted to technical sessions both in the morning and afternoon. If necessary to permit adequate discussion, an overflow session will be ar-ranged in the afternoon. In the evening, a subscription dinner will be given at the Copley-Plaza at which past-presidents John Hays Hammond and Robert H. Rich-ards will be guests of honor. It is promised that speeches will be short and dancing will be arranged for following. The women will be offered a luncheon and bridge party at one of the country clubs on Thursday, and Friday will be devoted to an all-day excursion for both men and, women. Members are asked to register promptly on arrival so that the various committees will know as early as possible for how many to provide. The major part of the technical program has been provided by the Committee on Geophysical Methods of Prospecting, and a series of papers of great value and interest in this new field has been brought together. Abstracts of substantially all of them are printed in this issue of MINING AND METALLURGY and the papers themselves will, with one or two exceptions, be avail-able in printed form at the meeting and later in the regular publications of the Institute.

Jan 9, 1928

By Hon. Tasker Oddie

DURING the closing days of the last Congress a resolution was passed, creating the Senate Com-mission of Gold and Silver Inquiry. The resolu-tion charges the Commission with the responsibility to investigate and report to the Congress on Jan. 1, 1924, upon the following subjects: 1. The causes of the continuing decrease in the production of gold and silver. 2. The causes of the depressed condition of the gold and silver industry in the United States. 3. The production, reduction, refining, transportation, mar-keting, sale, and uses of gold and silver in the United States and elsewhere. 4. The effect of the decreased production of gold and silver upon commerce, industry, exchange, and prices. The personnel of the Commission is as follows: Senators Pittman, Sterling, Goodling, Walsh and Oddie. At a meeting on May 8, H. N. Lawrie, a mining engi-neer and economist, was appointed as Assistant to the Commission. The present situation with respect to the gold and silver mining industries is well illustrated by the follow-ing data: The total world production of gold (in dollars) for 1915 was $468,724,918, and for 1921, $329,915,101; as shown by the reports of the U. S. Mint; and for the year 1922, $306,793,000, which is based oh a prelimi-nary estimate; this indicates a decrease of 34.5 per cent. between 1915 and 1922. The total world production of silver (in fine ounces) for 1915 was 178,850,000 oz.; for 1921, 175,268,234 oz., a decrease of 2 per cent.

Jan 6, 1923

By C. K. Leith

OTHERS here are far better qualified than I to discuss some of the specific proposals for government regulation of the oil industry. I shall make no attempt to carry oil to Oklahoma. The question of public control, however, is inherent in other branches of the mineral industry in varying degrees, and my comments will be directed mainly toward some of the trends affecting the mineral industry as a whole, as a background for your more specific consideration of oil legislation. A proud American tradition has been the insistence on freedom of competition, on equality of economic opportunity, on a policy of laissez faire. Nowhere has this principle been given wider application than in the mineral industry. The mineral field has been open to all comers, and the job of mineral exploitation has naturally attracted daring and independent spirits. The laws governing conditions of discovery and development, as well as the anti- trust laws, have been devised to foster the spirit of private initiative. The result has been the building of a mineral industry on a scale never before approximated anywhere in the world. The impetus thus gained, the methods, the technique, the financial resources, have been projected be- yond our boundaries and have made the American mineral industry the purveyor to the world for many essential commodities and first in the exploitation of the world's minerals. Our habits of individual self-reliance and success are deeply ingrained, and there is hardly an individual in the entire mineral field who does not instinctively recoil fro111 the extension of collective control, whether public or private.

Jan 1, 1932

By E. A. Jones

THE Southeast Missouri division of the St. Joseph Lead Co. normally hauls and hoists over 5 million tons of lead ore each year. This ore is mined in the stopes and headings of 20 mines, hauled to a main line system, see above, and transported up to 6.4 miles to ore-hoisting shafts. Average haulage distance is 2.16 miles. A few years ago a distinguished mining engineer visiting this area for the first time remarked, "You do not have a mining problem; yours is a haulage problem." Its relative importance may be gaged by the fact that mine haulage represents about 25 pct of the total cost of mining ore, the most costly single underground operation. The Southeast Missouri lead belt is a mining district located about 65 miles south of St. Louis. This district is roughly 6 miles wide and 10 miles long. The ore horizon lies about 400 ft below the surface where most of the ore is mined from flat-lying beds of dolomitic limestone. This paper deals with the central part of the district, namely, that portion which contains a group of interconnected mines all in a central haulage system, serving four hoisting shafts. The two major hoisting operations are carried out at Federal No. 17 shaft and Leadwood No. 12 shaft. No. 17 accounted for about 70 pct of the ore hoisted in the district during 1950, averaging about 14,000 tons per operating day. The underground dumping and skip-pocket system at this shaft is similar to those of the other shafts except that it has two rotary dumps. The other ore-hoisting shafts have only one. It might be mentioned that waste rock is hoisted at still other shafts, hauled off, and dumped on the surface by trucks. The hoisting shafts are on a connected system of about 200 miles of underground 24-in. gage main line railroad. There is also the Bonne Terre system, with its own ore-hoisting shaft, which consists of 13.5 miles of 24-in. gage main line, located in the extreme north portion of the lead belt area. Smaller outlying mines such as Doe Run No. 12 and Hayden Creek operate on trackless or shuttle car haulage. In addition to the system of main line haulage, each contributing mine group has its own extensive system of stope or heading railroad. Trackless mining is making considerable headway in the Lead-wood and Desloge mines. Here the shovel loads into a shuttle car which in turn dumps into mine cars spotted on the main line track system. When the merits of underground haulage and surface transportation are compared, it must be remembered that in early days there were many individual

Jan 1, 1954

By Joseph Hyde Pratt, Douglas B. Sterrett, CHAPEL HILL

I. DESCRIPTION. MONAZITE is one of the minerals which, for a long time, was considered rather rare in its occurrence, but, upon a commercial demand arising for it, prospectors and engineers soon located large deposits of it in the Carolinas and Brazil, and the supply has always been able to meet the demand. During 1908 further sources of supply of monazite have been discovered and developed in Idaho. North and South Carolina, however, are the only States that have thus far put any monazite on the market. Monazite is essentially an anhydrous phosphate of the rare-earth metals, cerium, lanthanum, and didymium (Ce, La, Di)PO;. There is nearly always present a varying but small percentage of thoria, ThO2, and silicic acid, SiO, which are very probably united in the form of a thorium silicate, ThSiO4 Some monazites contain but a fraction of a per cent. of thoria, while others have been recorded that showed the presence of from 18 to 32 per cent. ; but the majority contain from 3 to 9 per cent. of this oxide. It is the presence of the thorium oxide that gives the monazite its commercial value. The analysis occasionally shows also the presence of other constituents, as the yttrium and erbium oxides, zirconia, alumina, magnesia, lime, iron oxides, manganese oxide, and titanium oxide. Monazite is light-yellow, honey-yellow, reddish-, brownish-, or greenish-yellow in color, with a resinous to vitreous luster, and is translucent to subtransparent. It is brittle, with a conchoidal to uneven fracture, and is from 5 to 5.5 in hardness, and from 4.64 to 5.3 in specific gravity. It crystallizes in the monoclinic system, and some crystals have been observed that were 6 in. in length. The more perfect crystals are, however,

Jun 1, 1909

By W. M. Peirce

COMMENCING in 1922, each year a lecture has been presented to the Institute of Metals Division at this February meeting. The range of subjects has been very broad. Some speakers have dealt with the most advanced work in the very heart of the science of physical metallurgy. Others have stimulated our imaginations by discussing the most recent progress in related fields of science. Others have told us of the latest art, which is at any moment of greater practical importance than the latest science, of metals. I feel that this broad precedent in the choice of subjects will justify my choosing to talk about some of the prosaic details of how, during the last generation, industry has effectively organized research to accelerate progress in our own and all other fields of science and related art. A number of years ago I visited one of this country's well-known research laboratories and had the pleasure of chatting for a few minutes with its equally well-known director. Being particularly interested at the time in the organization problems connected with industrial research, I broached that subject. My host stated in effect that he didn't believe in organized research. He was, of course, resorting to a rhetorical hyperbole to point out the danger of overorganization which can so easily drift into regimentation and destroy individual initiative. Actually nearly all of us, much as we cherish our personal freedom of action, believe in organization because the history of progress in every field of human activity has been a history of men learning to work together, to cooperate, to create an efficient division of labor. We use organization to achieve this coordination. At the same time our form of organization must not stifle individual initiative or it will prove a deterrent rather than an aid to accomplishment. Research, too, must be organized for greatest achievement but especial skill and care are perhaps needed to avoid stifling the initiative of the individual workers. I have, of course, followed with keen interest and much benefit the vast amount that has been said and written on this subject in the past twenty years but I still find new stimulation in discussions with my good friends working in this field. It is my hope that this discussion may serve a like purpose. It would be ungracious not to make due acknowledgment to the many able contributors to this particular phase of human progress, but their very number and the great volume of their writing makes it impossible to trace to any one individual a particular significant and valuable idea. I shall content myself therefore with this general acknowledgment and with acknowledgment of the specific debt that every research man owes to those who have so ably kept before the public, and in particular before industrial executives, the place of research in the modern scheme of things. Because of the legitimate publicity thus given to research, the day is past when any

Jan 1, 1944

By Robert A. Jankowski, Charles D. Taylor

The objective of this program was to conduct dust surveys at six longwall sections having double-drum shearers, that were regularly in compliance, and to identify the dust control techniques that were the most effective. As each of the mines selected had a record of regular compliance with the Federal Dust Standard, all sampling was "short-term" (often less than 30 minutes) and no attempt was made to relate the survey results to dust-sampling results obtained by the companies for compliance purposes. The sampling procedures (1) used during this survey were developed jointly by the Bureau of Mines and Foster-Miller Associates, Inc. In addition to monitoring dust levels, measurements were also taken throughout the shift to monitor airflow along the face and water usage on the shearer. This program was a cooperative effort of the Bureau of Mines and the Mine Safety and Health Administration (MSHA). The following MSHA health specialists contributed to its successful completion: Paul Lenyo, CMS&H, Dist. 2; Ellis Mitchell, CMS&H, Dist. 3; Carl Jenkins, CMS&H, Dist. 4; David Stritzel, CMS&H, Dist. 8; and John Prelc, CMS&H, Dist. 9. RESULTS CUTTING SEQUENCE - WORK LOCATION At all mines surveyed, an important factor in controlling dust exposure at the shearer is the design of the cutting sequence so as to allow the shearer operator to work most of the time on the intake-air side of the lead drum. It is generally accepted that most of the dust generated by a double-drum shearer comes from the lead drum, which in the raised position normally takes a full sump. Because the position of the drum that is in the raised position determines the horizon control, the operator must be close enough to carefully monitor its operation. Therefore, his position relative to the lead drum has a significant effect on his dust exposure. Dust profiles, such as those constructed from data collected at Mines A and B (Figure 1), show the large gradient in dust concentrations that can exist between the intake and return air side of the lead drum. When the primary cut is taken head to tail, the lead drum is downwind and dust levels can be maintained at a low level until air has passed the shearer (Mine A). Thus, shearer operators can stay in relatively uncontaminated air. When the primary cut is taken tail to head, the lead drum is upwind of the shearer controls, resulting in higher dust concentrations at the shearer operator's work location (Mine B). At the mines where this cutting sequence was used, it was company policy for the shearer operators to walk on the intake side of the lead drum, returning to the controls only to adjust the height of the lead drum. DIRECTED WATER SPRAYS AND PASSIVE BARRIERS It is not always possible to keep the shearer operator on the intake air side of the lead drum. Various techniques have been tried to keep the dust generated by the shearer away from the machine operators when they work adjacent to the shearer. At all mines visited, the external water spray nozzles were directed so that dust from the shearer was directed downwind and toward the face, and away from the shearer operators. The effectiveness of using external water sprays to keep dusty air close to the face was noted during Bureau of Mines efforts to develop improved water spray systems (2). Laboratory and underground tests showed that water sprays located properly and directed downwind can create aiflow patterns that move dust generated by the shearer toward the face and away from the shearer operators. Sprays directed upwind, into the airflow, can actually move dust away from the face

Jan 1, 1982

By George C. Gibbons

ALMOST everyone in any of the five counties embracing the great East Texas field depends heavily upon oil for his living whether or not he actually owns a well or piece of royalty himself. Oil is a natural resource that, when utilized, spreads its benefits over a vast area and into many channels. Depending then almost entirely upon agriculture: what is now known as the East Texas oil field a decade ago had a scattered farming population. For many of its people, tomatoes and other vegetable crops coupled with the old southern stand-by of cotton, furnished an adequate living and a small cash surplus. Some farm families on the red hills, however, were not far re- moved from the sowbelly and black- eyed peas, or cornpone and potlikker, standard of living. Kilgore of that day, was a village of less than 850 per- sons. Longview, with just over 5000, apparently had reached the limit of its growth. Tyler was an overgrown farming town of around 17,000 persons, de- pending largely upon the agricultural income of Smith County and surrounding territory for which it was a trading center.

Jan 1, 1941

By Benjamin Gi ldersleeve

Uniquely colored, thin-bedded quartzite is quarried between Crossville and Crab Orchard in Cumberland County, Tenn. It is produced in all sizes up to the limits of transportation from beds usually ranging in thickness from less than 1/2 in. to 6 in. The stone is very resistant to wear and weathering and is marketed throughout the country for many different purposes in exterior and interior construction. The annual production exceeds 36,000 tons, valued at nearly $1,000,000.

Jan 1, 1950

By L. J. Ingvalson, Roy H. Miller

IN 1948, as part of a program to expand the copper tube mill facilities of the American Brass Co. plant at Kenosha, Wisconsin, plans were formulated to convert the 100 ton capacity anode casting furnace at the Great Falls, Montana plant of the Anaconda Co. to the production of 3 in. phosphor -ized billets. The furnace was rebuilt completely and construction was started on an addition to the building. Members of the Great Falls staff visited various billet casting plants to draw upon the experience of other producers of this type of casting. Many features of other plants were incorporated into the Great Falls plant but, in addition, many new designs were made and perfected to make the plant the most advanced of its type. Construction was begun in 1949, with the intention of having the plant in production in the early part of 1951. In January 1951, as the plant was being rushed to completion, the government placed restrictions on the production of copper tubing. As a result, work was halted and the plant lay idle for two years. Interest was reactivated in May 1953 with the lifting of restrictions on copper. Plans were laid to go into production in July and the first charge was taken out July 1, 1953. Basically the plant is designed to produce from cathode copper a 3 in. diam billet, 50 in. long. weighing 110 lb, and containing 0.013 to 0.036 pct P, at a rate of 150,000 Ib per operating day. These billets are to be pierced and drawn into tubing. Furnace The furnace is a 100 ton capacity reverberatory type, gas fired furnace; 21 ft long and 9 ft wide. Gas is introduced to the furnace through two 38 hole Mettler gas burners. These burners are of chrome nickel alloy with four jets per hole. The furnace is charged with cathodes from the Electrolytic Copper Refinery plus return scrap from the casting operation by means of a Wellman Seaver Morgan Co. 7,000 lb capacity charging machine. The charge crane has a 20 ft boom and fork peel provided with an air ram to push material off the peel. The machine travels on overhead tracks and can be moved in any direction. The boom can be raised and lowered and swung through an arc of 180". With well stacked units of 6,000 lb, an experienced operator can put the first charge into the furnace in 40 min. After charging, the steel framed silica brick charge door is put in place and sealed with clay. After melting and skimming off the slag, the copper is blown until an oxygen content of 0.40 pct is reached. The metal is then heated to 2180°F, covered with coke, and poled. Poling is continued until a 3 in. diam test billet, 8 in. long, shows a flat set. The oxygen content is usually 0.030 pct at this time. At the end of poling, a temperature of 2160" to 2180°F is desired. In the side of the furnace opposite the charging door is the taphole slot, extending 36 in. upward from the bottom of the furnace. It is 4½ in. wide at the outside face and widens to 9 in. at the inside face of the furnace. It is filled with a wet mixture of sand, fireclay, and crushed coal. Flow of metal

Jan 1, 1957

By Dennis H. Laubscher

INTRODUCTION The selection of mass mining methods is the situation facing not only planners of new operations, but also those involved with cur- rent operations, including the eventual change from open-pit to underground. Increasing ground control problems on many mines, plus a better understanding of dilution and ore loss problems have meant a review of current mining methods and support techniques. Experiments are only successful if conducted in the right mining environment and on the right scale. Mining personnel have been known for their conservatism and will tend to persevere with an established method rather than change; often, hidden costs will obscure the correct economic assessment. An established mining sequence is not necessarily correct in the long term. However, recommendations to change are usually met with opposition because of inconvenience, temporary production problems and the desire for a trouble-free guarantee. In any planning exercise, care must be taken that time and money are not wasted in trying to achieve the unattainable. During the decision-making period, production personnel must be involved, and, if possible, they should visit similar omrations to that proposed. Co-operative production personnel will help ensure success. Descriptions of mining methods are available in technical papers and books, and it is not intended to discuss this aspect, but, rather, the various factors which must be recognised before arriving at a final selection. In another paper presented at this Conference (Heslop and Laubscher, 1981) factors affecting ore recovery and dilution are discussed in greater detail for various cave mining methods. PRELIMINARY CONSIDERATIONS Comprehensive Geological Data. Geological information is available during the exploration stage, but, often, core from exploration drilling is not analysed with the selection of a mining method in mind. Drilling costs are high, therefore the maximum benefits must be derived from this operation. Holes which have not intersected ore may provide data on possible shaft sites, and 35 mm colour slides of core, sound logging and geomechanics classification, will provide a record which can be used with confidence at a later date. Intersections of the various rock types should be kept for future study; for example, is weathering likely to be a problem, bearing in mind that this can be accelerated in the warm, humid atmosphere of an underground mine. The accumulation of data required to select a mining method starts with initial geological work in the target area, whether this be surface mapping or a diamond drill hole. Publications. As technical papers, reports and books are used in the selection of mining methods, an appeal is made to authors to describe the geological environment so that readers can relate to their own conditions. Not enough emphasis is given to the problems experienced and the techniques employed to overcome them. Follow-up papers are seldom written and we should be prepared to discuss our failures. Diagrams are often misleading, as the ideal and not actual situations are depicted. The caved ore/waste interface is not a straight line, and whereas this may not be significant in a diagram of a 200-117 draw height, it certainly is in sub-level caving with draw zones only 1 - 2 m width but up to 20 m high. SUMMARY OF FACTORS AFFECTING THE SELECTION OF UNDERGROUND MASS MINING METHODS (a) Regional rock stresses and mining geometry. (b) The geomechanics rock mass classification of the orebody and surrounding rock mass. (c) Ratio of the surface area of the ore/unpay interface to the contained ore which determines ore losses and dilution. (d) The cavability and fragmentation data of the ore and hangingwall. (e) The mineral distribution in the orebody and its dilution zone.

Jan 1, 1981

By GILBERT C. DAVIS

ANY thought of Morenci naturally includes its sister town of Clifton, its gateway to the outside world. Clifton, the country seat of Greenlee County, is the terminus of a branch line of the Southern Pacific railroad from Lordsburg, N.M. Carload freight incident to the Morenci operation moves from Clifton over Phelps Dodge?s standard-gauge industrial railroad. Private freight must be hauled by truck. These two communities fell far short of supplying adequate housing for the personnel concerned with the new operations so a new townsite, Stargo, was developed adjacent to Morenci. Here 234 housing units with garages have been built and twenty similar units have been erected near the reduction works.

Jan 1, 1942

Although the meeting of the Institute in St. Louis Will not occur until September, 1917, the committee in charge is already making attractive plans, and we append hereto a tentative skeleton program which will give some notion of the opportunities that will be offered: St. Louis is situated in the midst of. a district which contains not only a great many interesting examples of mining, but also all types of industrial manufacture of interest to members of the Institute, and it affords abundant opportunities to visit and see these plants. Further announcement will be made from time to time as the committee's plans take more permanent shape. .

Jan 2, 1917

By Frederick M. Becket

AFTER all the chronology that has been given, what is the present status of chromium steels? For the purpose of this discussion the different types of chromium steels can be divided into three classifications-those containing relatively low , percentages of chromium, say 5 per cent or less; the medium-chromium steels containing up to about 18 or 19 per cent chromium; and the steels containing still higher percentages of chromium, and some of the special alloys. Chromium has some unique effects in steel, so it is well to make a few generalizations. The affinity of chromium for carbon is great and the metal is unique in the manger in which it supplements and enhances the effects of carbon. Chromium retards -considerably the thermal transformations on cooling and exerts an opposing influence both on the absorption and precipitation of the carbides in steel. These statements make it easy to understand the fact that chromium .steels are capable of producing a hardened product at a much slower rate of cooling than is, true of plain carbon steel, and that chromium carbide or -the mixed carbides of iron and chromium do not contribute to brittleness to as great a degree as does iron carbide.

Jan 1, 1929

By AIME AIME

THOUGH the dust-control systems in the crushing plants and other buildings at Morenci do not differ materially from similar installations in other large copper reduction works, it is probable that in few other plants has as much attention been paid to the dust problem. Possibly the most striking feature of the Morenci installation is the manner in which the necessary equipment has been built into the various structures, and the absence of unsightly pipes, ducts, and fan houses. That this result has been attained is due, in no small part, to the basic conception that the control of the dust in a milling plant should be an essential part of the process itself and not something to be tacked on later after the plant is in operation. The control systems were designed and developed along with the general plant construction program and when the first car of ore was dumped into the crusher the dust-control equipment was ready.

Jan 1, 1942

By J. S. Owens, R. W. Marsden, J. W. Emanuelson, R. F. Werner, N. E. Walker

The iron ores of the Mesabi Range occur in a 340 to 750-foot thick, Precambrian cherty iron formation termed "taconite." For about 65 years, extensive natural iron ore bodies were mined, and the ores either shipped as a direct ore or processed by gravity methods to a shipping grade iron ore. Since 1956, magnetite taconite ores, occurring in magnetite-rich horizons in the Biwabik iron formation, have been commercially concentrated and agglomerated. The transition from natural ores to concentrating-grade ores is progressing rapidly so that, in the near future, a major percentage of the iron ore shipped from the Mesabi Range will be as iron ore pellets produced from taconite. Natural iron ores of the Mesabi Range occur in the Biwabik formation as trough ore bodies in elongated channels and as irregular and tabular deposits in fractured areas associated with faults and folds. Ore bodies range in size from a few thousand tons to hundreds of millions of tons and may occur in any part of the iron formation. In some areas of strong ore development, ore was formed from the hanging-wall argillite to the footwall quartzite. The natural ores and beneficiating-grade natural crude ores were formed by the oxidation of the iron minerals, magnetite, greenalite, stilpnomelane, minnesotaite, and siderite, to hematite and goethite and by the removal of much of the silica in the cherty quartz and in the associated silicates by leaching. The ores are believed to have formed by the oxidizing and leaching action of surface waters. Magnetite taconite ores occur as stratigraphic zones in the Biwabik formation where it contains sufficient magnetite to be concentrated profitably, by magnetic methods, to give a magnetite concentrate that is agglomerated into a high quality product. Unoxidized taconite has an extensive distribution away from and between channels of oxidation and leaching but only a part of the unoxidized taconite is of ore grade. Two general types of magnetite taconite ore occur: ( 1) magnetite taconite of the Main Mesabi Range, generally west of Mesaba, which is composed of magnetite associated with cherty quartz, greenalite, stilpnomelane, minnesotaite, and carbonates and (2) magnetite taconite of the Eastern Mesabi, generally east of Mesaba, composed of magnetite associated with quartz, cummingtonite, actinolite, ferrohypersthene, hedenbergite, fayalite, hornblende, pyroxene, garnet, and biotite. The Mesabi taconite is a metasediment derived from an iron- and silica-rich chemical sediment that has been regionally metamorphosed and, on the eastern end, additionally metamorphosed by the Duluth Gabbro Complex.

Jan 1, 1968

By J. W. R. Rayner

THE conventional method of making water gas involves individual plants for the separate carbonization of coal to coke and the subsequent gasification of coke with steam. The process demands lump coke, preferably made from the best quality of coking coals. The ash in the coke should have a high melting point and the gasification process suffers a loss of efficiency when cokes with low ash-melting points are used. In Britain, these coals are generally the most expensive and they are readily available only in certain localities. The coals not suitable for making lump coke, or yielding only poor quality coke, are much more widely available and are generally cheaper. DEVELOPMENT OF ALTERNATIVE PROCESSES In Germany, processes have been developed and operated commercially for the production of water gas from very low-rank coals such as brown coal and lignites, but much less effort has been spent on processes to use coals of intermediate rank, which are widely available in Britain. The brown-coal processes use coal in the form of either dust or briquettes. The most successful of the dust-gasification methods is the Winkler process, which made a substantial contribution to German oil production during the war. It uses coal in the size range 0 to 8 mm and the fuel bed is blown with a mixture of oxygen and steam at a rate high enough to give it a characteristic boiling motion or, in present-day phraseology, at a rate more than sufficient to fluidize it (Fig. 1). Air cannot be used to provide the heat required for gasification, for vari¬ous reasons. In the first place, to make the process continuous by mixing air and steam would involve the production of a lean gas containing much nitrogen. If a separate blow were used, a large amount of potential heat would be lost because the blow gas in such a process would contain a very high percentage of carbon monoxide. Oxygen is necessary therefore and oxygen remains relatively expensive for use in gasification. In the Winkler generator, formation of clinker caused by local overheating does not occur, because of the mobility and high heat transfer of a fluidized bed. These properties of fluidized dusts have been used most successfully.

Jan 1, 1953

By Eugene McAuliffe

AS anthracite is no longer used to a marked extent by the rail- ways of the United States (1,513,000 tons in 1933), that portion of the mining industry engaged in the production of bituminous coal is, and will continue to be, the one chiefly concerned with the future use of its product by the railways. In a period such as the present, when all enter- prise is unsettled, when fundamental principles of industrial management and control are being swept aside or else changed overnight, it is difficult to predict what will happen. The relation between the total production of bituminous coal and the volume consumed by the steam rail- ways of the United States, Classes I,

Jan 1, 1936

By CHARLERS R. FETTEE

A slight decrease in drilling activity occurred in the oil fields of western Pennsylvania during 1945 and a considerable decrease in the shallow-gas territory (Upper Devonian or higher). The number of deep tests (Middle Devonian or deeper) completed was two less than in 1944 and these did not open any new reserves of natural gas. Thus far, no commercial oil has been encountered in sands below the Upper Devonian in Pennsylvania. Oil production declined 8 per cent.

Jan 1, 1946

By John D. Sullivan

MAJOR technical advances seldom occur in a single year, and this is especially true with aluminum and magnesium where marked improvements in metallurgical processes and products took place during the war years. Nevertheless, the light metals and alloys, particularly aluminum, are advancing in commercial importance and are finding their niche in industry. New applications during the year have resulted from a better over-all knowledge of properties, handling, etc., rather than from revolutionary new developments.

Jan 1, 1948