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By E. W. Davis

The mixing of fine ores with fuel and burning under induced draft is called sintering in iron-ore practice and either sintering or roasting in copper and lead metallurgy. The first development of sintering was the Huntington-Heberlein process, in which fine sulfide ores mixed with fuel were charged into a pot and burned under the action of an upcast current of air introduced at the bottom of the pot. Modern development has resulted in two types of machine; the continuous Dwight-Lloyd machine, which consists of heat-resisting grates and a moving beltlike type of hearth constructed of metal, in which air is drawn downward through the bed, and the stationary Greenawalt batch process, which operates in the same manner as the Dwight-Lloyd except that the hearth is stationary. The recent rapid increase in the use of sintering has been the result of two great advances in metallurgical process—flotation and the treatment of flue dust. The Dwight-Lloyd machine is used in many plants for agglomerating flotation concentrates and at the same time reducing the sulfur content to furnace requirements and it has become standard practice to treat iron blast-furnace flue dust by either the Greenawalt or Dwight-Lloyd machine, so that it can be recharged into the furnace. The mining of low-grade magnetite iron deposits and their beneficiat-ing by grinding and magnetic separation resulted in a fine concentrate extremely detrimental to blast-furnace practice. These concentrates are sintered and made into ideal material for blast-furnace use. Incidentally, coke savings of about 400 lb. per ton of pig are reported. Sintering at Evergreen Plant The application to limonitic iron ores is the most recent development of the sintering process. The first plant in the Lake Superior region was erected by the Minnesota Sintering Co., a subsidiary of the Evergreen Mining Co., at Ironton, Minn., in 1924. This plant was designed to treat Cuyuna Range iron and manganiferous ores containing low silica, high moisture and a structure objectionable because of a large proportion

Jan 1, 1930

By Amitava Gangulee

A recent investigation has shown that solid solution hardening is almost absent in the quasibinary system SnTe-pbTe.1 The lack of solid solution hardening was attributed to the small difference of only about 3 pct between the atomic sizes of lead and tin, and to the fact that the formation of these solid solutions involved changes only in the sublattice occupied by the lead and tin atoms. The investigation reported here is concerned with the quasibinary system PbSe-PbTe which, similar to the SnTe-PbTe system, forms a continuous series of solid solutions2 and has the same NaC1-type (Bl) structure. The size difference between the selenium and tellurium atoms, however, is slightly larger than 7 pct. No indication of any ordering of the lead and tin atoms at. selected compositions had been found in the system SnTe-PbTe, which had been explained by the weak second-nearest-neighbor interactions between lead and tin atoms.' The possible occurrence of an ordering transition in the system PbSe-PbTe was also investigated in the present work. Polycrystalline specinlens of PbSel-1-xTex (x = 0, 0.20, 0.25, 0.33, 0.50, 0.67, 0.75, 0.80, and 1.0) were prepared by melting appropriate amounts of 99.999 pct pure Pb, Se, and Te j.n evacuated and sealed Vycor capsules. The capsules were quenched in water. The solidified ingots were homogenized at 800°C for 14 days. Chemical analysis of the homogenized ingots showed that the deviations from the stoichiometric compositions were less than 0.1 at. pct for each component. Part of each ingot was ground to pass through a 75 g sieve and pressed into 25.4 mm by 12.7 by 2 mm briquettes. Duplicate sets of specimens, each containing at least one briquette and part of the ingot of each composition, were sealed in evacuated Vycor capsules. Both sets were annealed at 500°C for 7 days; one set was quenced in ice-water and the other was cooled to room temperature over a period of 14 days.

Jan 1, 1970

By Walter Crafts

Tests carried out at the Union Carbide and Carbon Research Laboratories, Inc., on the effects of grain-refining deoxidizers are in substantial agreement with the data presented by Mr. Comstock. Notable is the observation that, although boron and aluminum increased hardenability, the steel was of poor quality in comparison with the other boron-treated steels to which at least two grain refiners were added. The effect of zirconium in improving the ductility of the chromium-nickel steel is in agreement with our experience that zirconium is specifically beneficial to chromium steels. In order to amplify Mr. Comstock's results and to indicate some of the basic principles of special deoxidation, the primary observations of our study have been summarized. The effect of boron in increasing hardenability was described by R. Walther, U. S. Patent No. 1519388, Dec. 16, 1924, but effective amounts in incompletely deoxidized steel are sufficient to harm hot workability and room-temperature ductility. Work at the Union Carbide and Carbon Research Laboratories, Inc., has shown that in order to obtain deep hardening without using such large amounts of boron as to result in impairment of ductility, the steel must be thoroughly deoxidized. This may be accomplished by a high silicon content or a grain-refining addition of strong deoxidizers. The degree of grain refinement and hardenability are inclined to be erratic when only one grain-refining element is used, although aluminum, zirconium, titanium, and vanadium have been used singly and resulted in increased. although somewhat erratic, hardenability. The ductility likewise was inclined to be inconsisterlt when only one grain-refining deoxidizer was added. By combinations of grain-refining elements, it was found possible to combine the specific virtues and counteract some of the defects of each clement. In addition, the complex deoxidizers gave more consistent grain refinement and hardenability. When used in combinations, each element adds its own specific influence as well as modifying the character of the other elements. The function of aluminum is primarily to give consistent results and to minimize abnormalities resulting from too

Jan 1, 1943

By Arthur Knapp

Oil-well depletion curves, to be of value, should show when a well or lease may no longer be operated at a profit. The difference, at any time, between the total expenditures and the total income of a lease or well may be called the lease status. Plotting this lease status against time will give a curve subject to more accurate and different interpretations than the barrels-time curves. According to the hypothetical barrels-time curves shown in Fig. 1, well A, at the end of 16 mo., is producing twice as much oil as well B and will continue to produce for another year whereas well B will cease producing in about 6 months. Data fob Lease Status-time or Dollars-timb Curve Time Lease Months Status Lease purchased for $3000.............................. 0 — $ 3,000 No expenses chargeable to lease for 3 mo................. 2 — 3,000 Well A is started; cost of drilling for month is $16,000..... 3 — 19,000 Well is completed at additional cost of $10,000............ 4 - 29,000 Well A is brought in and flows 10,000 bbl. first month (we Fig. 1). Necessary to invest in tanks, boilers, pipe lines, etc.; difference between expenditures and receipts gives profit for month of $5,000............................ 5 — 24,000 Investment is small, cost of operating well A is small, so profits are $15,000................................... 6 — 9,000 Well ceases to flow so there is additional investment for pumping equipment and additional operating expense; net earnings from 6,000 bbl. of oil produced is $4,000. 7 ... Lease operation nor becomes normal and curve becomes smooth........................................... 8 — 500 9 2,000 10 4,500 11 6,000 12 7,700 13 8,700 14 9,000 15 9,500 16 10,000 A hypothetical lease status-time, or dollars-time, curve of this lease is shown in Fig. 2. At zero time, the lease is purchased for $3000, which is plotted below the zero dollar line, All subsequent entries are plotted

Jan 1, 1921

By Theron Wasson

Discoveries in Michigan, which at the beginning of the year 1934 indicated possible new areas, did not develop into fields of market-breaking proportions. Hart, Oceana County, developed small production from the Traverse lime. Edmore, Montcalm County, proved a small area for oil from the Traverse. West Branch, Ogemaw County, previously reported as Ogemaw, had quite a drilling campaign but was somewhat disappointing because wells were small and erratic. During the year, 30 wells were completed at West Branch, and at the end of the year 15 others in and around this field were under way. At West Branch the Traverse lime, found at 1800 ft., has thin porous streaks near the top, which make small wells; the Dundee lime at 2800 ft. produces from a porous zone of varying thickness. Over the entire field the Dundee wells average 10 to 20 bbl. per day. Acid treatment has materially increased production from some Dundee wells in this field. About 3000 acres have been proved productive from the Traverse and Dundee. At the close of the year the well in Beaverton township, Gladwin County, is probably the most discussed of any in Michigan and may be opening a new field of some proportions. It had an initial production of 70 bbl. daily from the Dundee lime at 3830, which has decreased to 25 bbl. per day. Deeper drilling into the lime may increase production. During 1935 the area around this test will probably be the most active in the state. Structural conditions in Gladwin County, as in other parts of Central Michigan, are obscured by a thick mantle of glacial drift and it will take considerable drilling to outline subsurface conditions accurately. The most important new shallow gas area of the year is around Edmore in Mecosta and Montcalm counties. Eight wells have been drilled to the Michigan stray and the upper Marshall sand, having a combined initial production of 30 million cubic feet. These gas wells are scattered over so wide an area that an estimate of proven territory cannot be made until more drilling is done. At the present time no gas is being sold from Edmore.

Jan 1, 1935

By John Jermain Porter

In taking up this subject it is first necessary to define our terms. Efficiency, in its engineering usage, means the ratio between actual and theoretical results, and efficiency-records thus involve the use of scientifically determined standards with which all results are compared. Scientific management is the methods used in increasing efficiency, and includes the use of efficiency-records. Efficiencj-records do not alone constitute scientific management, but they are necessary to it, and any so-called system of management which is not based upon standards and standardization is fundamentally wrong. An efficient management and efficiency-methods in management are not the same thing. There are some people who have an instinctive genius for management and accomplish results without exactly knowing how they do it. Such a manager may obtain a very high efficiency without the aid of scientifically determined standards. On the other hand, it sometimes happens that poor results will accompany the use of efficiency-recorcis, due to a weak or indifferent management, which fails to make use of the information acquired. Efficiency-records are only a tool, and like other tools are worthless unless used. The ordinary cost-sheet and production-statement do not go far enough. They tell what has been done, but give no information as to how well it has been done. It is true that the man who is familiar with the industry and the plant in question may draw inferences and form a general idea of good work or bad work, but it can only be a very general and hazy idea. Comparisons with previous records or records of other plants are unsatisfactory, since there is nothing to show the cause of the differences. Efficiency-records supply this need. They compare actual

Jan 1, 1913

An Outline Classification of Mining Systems for Ore and Coal. See COAL Progress at the Homestake Mine. By Guy N. BJORGE. (Min. & Met., June, 247. 4400 words.) Homestake's mining methods today are controlled to a con¬siderable extent by that which has been done in the past. The two main operating shafts were begun m 1878 and 1896 respectively, so that the location of shafts, loca¬tions of all the drifts on the upper levels, and a great deal of stoping was done before any of those now connected with the mine had anything to do with it In this paper is described the general plan of development. A table shows percentage of total production mined by the different methods in recent years. Average daily produc¬tion for several years now has been about 3850 tons milled. With the present schedule of 6-day operation of the mine, that means about 4450 tons a day mined This ore is treated at three plants, with respective capacities of 2000, 1200 and 600 tons The principal novelty in milling is at the largest mill where the stamps are used as crushers only, and where in the last two years a notable increase has occurred in the size of screens used A unit has been added to cyanide plant No 3 The construc¬tion of a new shaft is described, as is also the hoist building The company operates its own lumber and timber department It has a well equipped hospital Housing at Lead is an individual matter. Rejuvenating the Golden Chariot Property in Idaho. By R. S. MCCLELLAN (Min. & Met, November, 443. 2300 words) An effort to rejuvenate the Golden Chariot group of properties near Silver City is now being carried on by the John Hays

Jan 1, 1935

By Foster J. Witthauer

First mining operations in the Tyrone District, located just north of the Burro Mountains in Grant County, New Mexico, commenced in the 1870's. A major operation was undertaken by Phelps Dodge Corporation in the early 1900's when a 2,000 ton per day underground mine was developed and a gravity concentrator was built east of the mine and across the Continental Divide. It was during this time that the picturesque Tyrone townsite was built and occupied. In 1921, however, the underground operation was closed because of high operating costs and low demand for copper. The area was drilled extensively during the 1950's and in October 1966 Phelps Dodge announced the pending development of the new Tyrone with a large open-pit mine, a modern concentrator, suitable support facilities, and a new townsite to be located between the mine and Silver City. Stripping for the pit and construction of shop and milling facilities began in 1967. By the spring of 1969, ore was being stockpiled near the primary crusher. Operation of the concentrator on a 3-shift per day basis commenced on July 17, 1969. The concentrator as initially built had one primary, two secondary, and five tertiary cone crushers, two grinding sections of six ball mills each, two flotation sections, four filters, and four tailing thickeners. The capacity was about 30,000 tons per day. In 1971 and 1972, the capacity was increased to 48,000 tons per day by the addition of one secondary and two tertiary crushers, one section of eight ball mills, one flotation section, two filters, and four more tailing thickeners. Centralized automatic control was built into the original and expanded facilities to the greatest extent possible, considering the state of the art at that time. Installation of additional control

Jan 1, 1976

By Basil B. Zavoico

Production of crude oil in the U. S. S. R. during 1939 is estimated at, 226,111,000 bbl., as compared with 219,778,000 bbl. in 1938, an irlcreasc of 2.88 per cent but some 6.00 per cent under the planned output. During the past year a major readjustment took place in Russian oil fields, with the Grozny district falling into the third place, its former place having been taken by the fields of the Maikop-Kuban area of northwestern Caucasus. Production continued to grow in the Ural-Volg:t district and further large increases in this province in the coming years are certain. The drilling operations continued to be most unsatisfactory, falling far behind the plan, possibly as much as 25 per cent undvr the set objectives, and thereby interfering with the production plans, mora particularly since the Soviet oil industry is still based primarily upon the production from the naturally flowing wells without any proration whatsoever rather than upon stabilized production from either prorated oil wells or those operated with various mechanical lifts. The year 1939 started with the fulfillment of the drilling programs to the extent of about 90 per cent, but the situation rapidly deteriorated arid by the second half drilling programs were being fulfilled only to the extent of 60 per cent or less. Such breakdown in drilling operations was possibly due to poor equipment, which has not been able to stand increasing demands upon it, and this is substantiated by the rccent orders plaeed in the United States by the Soviet Government for some 60 drilling rigs of the latest design. Production Baku District.—-The fields of the Apshcbron Peninsula (Baku district) made a notable progrress during the past year and were able slightly to increase their production, to 166,000,000 bbt. as compared with 164,692,-000 bbl. during 1938. The c.rnphasis of production in the Baku district remained on the flowing wells, about 20 per cent of the total number of wells flowing about 70 per cent of production. During 1939 some 550 wells were complr.tcd in the Baku district with active rigs averaging

Jan 1, 1940

By F. R. Hewitt

The methods of mining talc are simple, and in western North Carolina are almost entirely by open cut and quarry. The larger part of the talc of this section lies in various-sized "veins''. inclosed in quartzitic walls, the majority of which have by folding been thrown into a perpendicular position, or nearly so, and the exposed edges of which have been covered by debris from erosion of the mountain above. This covering of loose rocks and earth is from 5 to 25 ft. thick, and in most cases has to be removed because it is difficult to support. Sometimes the covering is heavy enough to "catch" and timber successfully, and in this case the talc can be worked out by the usual method of following the "vein," using stulls for holding up the walk until the vein is worked out, and then allowing the cut or drift to fall in. In some cases it proves more convenient to sink shafts and run drifts, following the talc "veins" until exhausted. The talc deposits of this section are badly broken and faulted both laterally and perpendicularly, and in some cases are found many feet below the level of drainage, necessitating pumping at considerable expense. My own experience in mining talc has been that the chief point is to get a reliable "vein," and that then the mining is not as difficult, or any more so at least, than that of any common ore. If the "veins" are pure talc it is simple; if the talc is admixed with foreign matter, such as tre-molite in excess, or stains of iron or manganese, as is often the case, one had better abandon the deposit. Methods of Manufacture Talc, being a soft mineral, is not difficult to reduce to the condition desired by the trade. Powdered talc is admitted under low duty from France, Italy and Austria, and some is being imported from Asiatic points. Talc is usually ground and bolted in any simple reduction mill. That mined in this section is hand-sorted and the quality that will make good powdered talc is ground for use in the manufacture of talcum powder, cosmetics, etc., while all that is hard enough and has sufficient strength is used for crayons and blanks for gas burners and electrical work, being sawed into the shapes desired. The rest that is clean and pure is ground

Jan 1, 1917

By George Smith

Introduction THAT an oil-land law is the most needed item in the proposed program of mineral-land legislation follows from the fact that Congress has never enacted a law really applicable to petroleum and natural gas. The action of Congress in 1597 in authorizing entry of oil-lands under the placer law, enacted 27 years before for the mining of gold in surface gravels, was plainly only makeshift legislation. Naturally the provisions of this placer law with its requirement of discovery as a prerequisite to location are nothing less than absurd when applied to petroleum deposits hundreds or thousands of feet beneath the surface. Other reasons which render oil-land legislation an urgent necessity arise first from the large acreage of lands believed to be valuable for their deposits of oil and gas and therefore withdrawn by Executive order from all entry pending the enactment of an appropriate law for their disposition-a withdrawal that has been specially ratified by Congress in the case of one State, Utah-and second from the exceptional importance of this resource to the nation, the large industrial worth of petroleum, and indeed its paramount value to the navy, not being suspected 17 years ago when Congress last legislated upon this subject. Mineral land of this type is also well adapted to serve for purposes of illustration in discussing the general principles that demand recognition in legislative reform. Most of the issues involved in the consideration of oil-land legislation are clean-cut, and essential differences of opinion will be seen to be based upon radical divergence in economic theory rather than upon conflicting views concerning unimportant details. For the last five years or more the geologists of the Federal Survey have discussed this subject and prepared memorandums and reports on .the various bills introduced in Congress. Most of the provisions suggested in the present outline have been under consideration at one time or another during that period, and many of the statements which follow can be said to represent the consensus of opinion among those of us who, both in the field and in the office, have given special attention to the public oil-lands.

Jan 6, 1914

By F. A. Howard, R. T. Haslam

In a broad sense automotive fuel is simply fuel in general and includes coal, coke, wood, charcoal and gas, in addition to the full range of liquid combustibles. All of these are actually used, or have been used, commercially to some extent as fuel for automotive vehicles. The steam lorry burning coal and coke is a common sight on the roads of England. The fact that these coal-fired steam lorries have a distinct advantage in taxes over the conventional gasoline-driven lorry probably explains the survival of this vehicle. The omnibus, or charabanc, operated by city gas carried in a balloon container on the roof, was also at one time a common sight in England, although not as common as the ubiquitous steam lorry. These gas-operated vehicles have, however, disappeared from the streets in recent years, and probably owed their existence entirely to war conditions. In France one of the largest motor vehicle manufacturers had last year more than 30 trucks equipped with regular gasoline engines in service in the Parisian area operating on producer gas obtained from a small gas producer mounted on the running board of the truck. Both wood and charcoal have been used in these gas producers. The authors were interested enough in this unique commercial development to spend some time examining the apparatus used and inquiring into the success which it had met. The picture is by no means an impossible one purely from the standpoint of practicability, but there is no doubt of the soundness of the conclusion that this is not a development which has any present important significance. Powdered carbonaceous matter, coal, coke or lignite, has been used experimentally in special forms of internal combustion engines, but so far as is known, these have never been applied to automotive practice. Range of Liquid Combustibles In the field of liquid combustibles the full range has been exploited to some extent. Heavy residual fuel oils from petroleum have been

Jan 1, 1928

By David B. Reger

The year 1935 was mostly quiet in West Virginia, and devoted to routine drilling in old pools and extensions. A notable exception to this general rule, however, was the further development and proving of a field of gas discovered in 1930 in the deep Oriskany sand (L. Dev.) in Kanawha County, as later discussed. No new pools of oil were found and little or no attempt was made to search for them. No new pools of gas were recorded but various extensions of old pools were made. There were no new pipe line extensions of consequence, either for oil or gas. Operating technology was much the same as in recent years, there having been some further advances in repressuring oil wells and in the use of acid for treating small wells in calcareous formations, and some change in the technique of shooting gas wells. Financially, there has been a full market for all crude oil produced and a fair market for gas. There have been occasional transfers of producing oil or gas properties, mainly between established companies. Most of the attempts made to finance mergers and new developments have failed largely because of difficulties encountered under the Federal securities act. This situation has prevented the normal turnover of properties by small operators who frequently desire to sell partly developed interests and then step out into new ventures. New Development In 1935 the State issued 569 permits for drilling and records the same number of completions. One trade journal records 533 completions and another 483. A running record kept by the writer accounts for 713 completions, with 156 oil wells, 417 gas wells and 140 dry holes (Table 3). Some of these completions may be old wells drilled to deeper sands. Some, apparently, have been drilled without legal permit. Extensions of Producing Areas Ritchie County has again led all others in new drilling, with 137 completions as compared to 74 in Calhoun and 61 in Cabell. This Ritchie County drilling was done mainly to extend or further develop old pools

Jan 1, 1936

THERE was presented for discussion at the February (1924) meeting of the American Institute of Mining and Metallurgical Engineers a report of a committee named by the United States Bureau of Mines on the Use of Oxygen or Oxygenated Air in Metallurgy and Allied Processes. An extensive discussion followed the presentation of the papers, which dealt with the matter entirely from a theoretical standpoint. The results of only a limited, amount of research work were presented and discussion centered around the question: "Is it worth while to carry on research and expend money in determining what can be done in metallurgical operations if cheap oxygen can be produced?" More experimental work on this subject has not been done because metallurgists have not thought that cheap oxygen could be produced, thinking "Why waste time experimenting. with a reagent that cannot be procurable in commercial quantities?" While the producers of oxygen have said " Why waste money on the development of a process to make cheap oxygen unless we know that there will be a market for it when produced?" The discussion brought out two facts: First, many metallurgists believe that their operations can be conducted more economically if they can add oxygen to the air used in various smelting operations; second, a number of chemists believe that relatively pure oxygen can be produced in metallurgical quantities at very small cost. Negative views were expressed to both propositions, but so overwhelming was the view that if cheap oxygen could be produced, many metallurgical operations would benefit that it was voted to recommend that the Bureau of Mines continue its research work, pending the production of the cheap oxygen hoped for. Few experimental data being available, and the attitude of disputants being based largely on theoretical considerations or on reactions and temperatures incapable of positive proof, it has been decided to publish only a summary of the papers and discussions arising from their presentations. It is believed, however, that this will be sufficient to show the lines of reasoning that have been adopted, and be a guide to others who are to make their own calculations or engage in experimental work.

Jan 11, 1924

By AIME AIME

ONE of the few students to enter the world's first department of ceramic engineering a few years after its establishment at Ohio State University, A. F. Greaves-Walker has since established an international reputation in that field. Before accepting his present position as professor and head of the department of ceramic engineering at the State College unit of the University of North Carolina, Dr. Greaves-Walker spent twenty years in the ceramic and mining industries in Kentucky, Utah, Ohio, Alabama, Ontario, Pennsylvania, and Georgia successively, holding the positions of chief chemist, mining engineer, chief engineer, sales engineer, chief of research, production manager, and finally vice-president. This industrial experience resulted in his building up one of the outstanding departments of its kind in the country.

Jan 1, 1942

By M. E. Straumanis, S. M. Riad

The lattice parameter of 99.999 pct pure Ag rtlas redetevnzined and found to be az5 = 4.08626 5 0.000041 with the vefnzctiotz correction included); the expatzsion coejjicient between 10° and 65°C was 18.73 X10-6°C-1. The lattice paratneter increased upon solution indium in silver in good agrement with other authors. The solid-solubility limit around room temperature was at 20.4 wt pct of in, which suggests that the high-temperature solubility (at about 689°C) determined by other authors is too low. The expansion coejficient of si1ver increases with the itzcrease of indium content between 10° and 65° C from, 18.73 (In = 0) to 20.9 x 10-6°C-1 (In = 20.4 pct), being only very slightly influenced by small amounts of indium. The expansion coefficents of all solid solutions increarsed strongly with temperature, reaching values > 27 x 10- 6 800°C. ACCORDING to the Ag-In diagram,' the solubility of indium in silver (the a phase) extends to about 18 pct by weight at room temperature. However, there has been only one investigation of the solubility limit by X-ray methods—that of Weibke and Eggers.2 Hume-Rothery, Lewin, and Reynolds measured only the lattice parameters of Ag-In solid solutions3 as did Owen and Roberts4 and Adler and Wagner.' The thermal expansivity of four solid solutions was determined by Owen and Roberts4 in a temperature range between 25" and 300°C. In view of the limited amount of work on Ag-In solid solutions, it seemed appropriate to redeter-mine the lattice parameters and the room-temperature solid-solubility limit, to find the exact expansion coefficients of the solid solutions at about room temperature (between 10° and 60°C) and the expansivity up to 800°C, and finally to derive the thermal-expansion coefficients for any alloy within the solid-solubility region. THE ALLOYS AND THE DETERMINATION OF LATTICE CONSTANTS The metals used were 99.9991 pet pure, supplied by the ASARCO company. Both silver and indium were weighed accurately on an analytical balance in

Jan 1, 1965

By C. A. Hartnagel, D. H. Newland

The market for Pennsylvania grade showed a drop both in demand and in prices, which reacted unfavorably on New York oil production, all of which comes under that classification. The output for the year in New York amounted to 5,045,200 bbl. The production in 1937 was 5,478,000 bbl., the largest in any year for the last half century or more. Falling prices, of course, affected new drilling. They declined from $2.20 a barrel, which was posted at the start, to $1.68 in the final months of 1938. With this came a reduction in the amount of oil that would be accepted by the refineries operating in the New York fields. Conditions therefore have combined to halt, at least temporarily, the growth of oil production in the state, which had experienced a steady gain for the last 15 years or more, the yield having risen from less than 1,000,000 bbl. to the round total of 5,500,000 bbl. in 1937. Practically all the oil now obtained is from old, developed fields. No new pools have been found in the last quarter of a century or more. The larger share comes from flooding the sands. Although there are many wells that still produce without the aid of the water drive, they are small and for the most part are pumped periodically. Of late, new drilling has been restricted mainly to that required to maintain existing flood projects. Because of the high initial cost and time required to put a flood into production, the depressed condition of the market has been a serious handicap financially, and, further, has been an unfavorable influence on the planning of operations to secure the maximum recovery of the oil. Unless market conditions improve, it is certain that the effects will be shown in the yield for some time to come. Gas Developments Drilling was active in the southwestern area, chiefly in Allegany and Steuben Counties, and some notable wells were brought in that tapped the Oriskany sandstone. Altogether 42 holes were put down in the two counties, of which 31 were listed as producers and 11 were dry. The new wells gave an initial daily flow of 239,000 M cu. ft. At the close of

Jan 1, 1939

By Richard S. McCaffery

This paper considers certain aspects of the acid bessemer process, particularly in its relations to the duplex process—that combination in which the pig iron is first desiliconized and decarburized in acid bessemer converters and then dephosphorized in basic open-hearth furnaces. The acid bessemer process employs an acid-lined converter and produces an acid slag. The blow is usually thought to eliminate the silicon and manganese as oxides and then to burn off the carbon as carbon monoxide On account, however, of the relatively large amount of metallic iron present in the converter, compared with the relatively small amount of the impurities it is desired to oxidize, the first reaction in the converter probably is the formation of iron oxide, which dissolves in the bath and acts as an oxygen carrier for the silicon and carbon. As soon as iron oxide is dissolved throughout the bath, the oxidation of silicon commences; but in the early stages of the blow the mass law would indicate that iron oxide must form first, and this oxide probably increases up to some saturation point. The molten metal in the converter from the early stages of the blow right through to its completion remains basic, while the slag produced is siliceous. This fact is shown by the corrosion of the acid bottom and the tuyeres, which is greatest at the tuyere orifice where oxidation is most active and where there is the most iron oxide. Why does this acid bottom corrode? Because it is attacked by a base. The thought, therefore, suggests itself, why not. make the bottoms of basic or neutral material?' As the converter slag is acid, those parts of the converter coming in contact with the slag should be acid; but those parts of the converter that are in contact with the molten metal saturated with metallic oxides should be basic. or neutral. Bessemer operators have for some time tacitly admitted this condition, for the blast pressures have steadily increased with the object of keeping the metal in suspension, and so preventing bottom corrosion; if the molten metal were not basic, it would not attack an acid bottom. In addition, the tuyeres are bunched together at the middle of the bottom and a clear space is left around the outside of the bottom; if tuyeres are placed too near the side walls the

Jan 1, 1922

By W. F. Boericke

The character of the Wisconsin orebodies must be clearly understood to appreciate the difficulties encountered in sampling and estimating them. Unlike the western vein deposits, they do not lie between regular walls, but form large, often highly irregular bodies, on a single floor in the so-called Galena limestone. The bottom of the ore is nearly always on the clay bed (a flat generally well-defined clay seam a few inches thick) which marks the junction of the base of the Galena lime and the top of the next formation, the Trenton lime. Above the clay bed, the orebodies make the unique pitch and flat formation described by Chamberlin.' Theoretically, we should find two pitches, one on either side of the top crevice, diverging as they go down, with the final flats a considerable distance apart on the clay bed. The area between, known locally as core ground, should thus constitute a single defined orebody, with the richer portions near the pitches and the leaner portion in the center of the core. Practically, we find few examples of this perfect orebody. Almost invariably one pitch is better defined than the other, and often the opposite pitch is marked only by a faint line of fracture showing stronger mineralization than the wall rock, or it may be totally lacking. But with an orebody of any size or richness, at least one strong pitch usually tends to follow an east-west trend, or a quartering course. Late mining developments in the rich New Diggings field indicate that these pitches often assume a horseshoe or crescent shape, the richer ore being in the heart of the crescent and the pitches showing less mineralization as they extend outwards. In the northern end of the field, on the contrary, the pitches maintain generally a consistent direction, and have been mined for thousands of feet from the shaft. The length of the orebody may be several thousand feet, the height varying from 10 to 60 ft. and the width from 60 to 250 ft. In fact, on the core side, there is no definite end to the ore. The mineralization simply gets thinner and thinner, and the limit of working depends on the cost sheet and the profit from the recovery.

Jan 1, 1923

By J. Parke Channing

The Miami orebody occurs in an altered Pinal schist. It is popularly known as one of the '(porphyry " deposits but, as at Inspiration and Ray, the ore is an altered mincralized Pinal schist. The orebody mined is the zone of secondary enrichment. Speaking in general terms, the area of the orebody at Miami may be considered as 1000 ft. long and 800 ft. wide. The vertical thickness varies from 200 to 400 ft., so that it is an extremely irregular mass. The study of the ground movement and resulting subsidence at Miami is complicated by the fact that the formation is not homogeneous throughout the mining area, the orebody terminating on its eastern extremity at a fault plane adjoining the Gila conglomerate. This conglomerate is a recent sedimentary deposit somewhat analogous to glacial drift and consists of boulders of granite, schist, and other material cemented with clay, and at times is quite hard. The fault dips eastward at an angle of 45". The original method of mining was top slicing, the slices being 10 ft. thick. At first, there was a good deal of experimenting with mining methods. Some undercut rooms were tried, and the stopes were filled with broken ore with the idea of removing intervening pillars by top slicing. The adoption of the top-slicing method in itself involved considerable experimenting, including some experiments with a long-wall system. The method finally adopted involved the operation of top slicing areas 250 ft. square, each with a central supply raise and ore-gathering raises, each block being worked as a unit. Mining operations in the Captain orebody, which connects with the boundary of the Inspiration property, were started by the room-and-pillar system, the rooms extending across the orebody, with widths of 10 to 15 ft., with 15- to 10-ft. pillars between. The intent was to operate the rooms as shrinkage stopes, permitting the pillars to crush when the ore was drawn from the rooms. It was found that the shrinkage stoping was unnecessary, so a system of block caving was adopted. This system was so successful in the Captain orebody that, about three years ago, the method of mining in the orebody was changed from top slicing to block caving, the method now in use. The block caving system, as practiced

Jan 1, 1923