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Jan 1, 1957

Coal - Surface Mining Coal Preparation Coal Utilization Research and Development Health and Safety

Jan 3, 1976

By Hal T. Morris

The main Tintic mining district in central Utah has produced approximately 13,500,000 tons of ore, containing silver, lead, gold, copper, zinc, and other metals, valued at more than $315,000,000. More than 90 per cent of this ore has come from large, irregular ore bodies that have replaced folded and faulted limestone and dolomite strata. Of lesser importance are replacement veins that chiefly cut contact-pyrometasomatized carbonate rocks and fissure veins that cut altered intrμsive bodies and volcanic rocks. The district is in the west-central part of the East Tintic Mountains, a north-trending fault-block range near the eastern margin of the Great Basin. The consolidated sedimentary rocks exposed at the surface and in mine workings are miogeosynclinal deposits more than 10,000 feet thick that range in age from late Precambrian to Late Mississippian. They are folded and strongly faulted and are partly overlain by volcanic tuffs and agglomerates and by extensive flows of porphyritic and vitrophyric quartz latite, latite, and trachyandesite of Eocene age. All of these rocks are locally concealed beneath thick alluvial deposits of Pliocene and Quaternary age. The Eocene and older rocks are cut by dikes, sills, and small stocks of porphyritic quartz monzonite, monzonite, and latite, which are genetically related to the ore deposits. The district is inactive except for the production of halloysite clay and for minor leasing activity and exploration ventures. Several exploration targets remain untested.

Jan 1, 1968

Charles Catlett, Staunton, Va. (communication to the Secretary*):—Mr. Chance's suggestions that the brown hematite-ores of the Potsdam formation are due to the alteration in place of iron sulphide, and that their extension may reasonably he expected to contain valuable deposits of unaltered sulphide, are interesting; hut the facts marshaled by him are too limited

Jan 1, 1909

By John V. Beall

The forecast of continued growing demand for phosphate, chiefly for fertilizer, has caused a world-wide rush for deposits by a variety of companies many of which have never before mined phosphate rock. The newcomers are diversifying into this growth industry on the strength of certain capabilities. Among these are the availability of investment capital, mining or processing know-how and marketing experience. Product tie-ins have motivated some into the search. Companies with excess sulfuric acid or potential for making it are in this category. This acid is the most commonly used for dissolving phosphate rock to make phosphoric acid. Base metal smelting companies are prime candidates in this field with by-product acid from roasting processes. Producers of "sweet" natural gas, such as those in Louisiana and Texas, have a potential for recovering low cost hydrogen from excess gas production for the manufacture of ammonia, the main source of nitrogen for fertilizer. "Sour" gas producers, such as those in the Canadian fields, are making sulfuric acid that is combined with western U.S. phosphate to make fertilizer materials. The presence of one or two steel companies in the look-see for phosphate deposits is based on by-product ammonia from coke-oven gas.

Jan 10, 1966

By Alfred James

Some months since, in the Johannesburg gold-fields of South Africa, the attention of the author was directed to certain statements to the effect that the gold-contents of foul or extremely dilute cyanide-solutions could not be effectively precipitated in practice by the usual zinc-method. Such statements caused all the greater surprise, because it is well known that this difficulty is not encountered in other wellknown districts, as, for example, in New Zealand, where solutions containing less than 0.05 per cent. of KCy are regularly reduced in practice to below 1 grain of gold per ton, while in Mexico and the United States almost equally satisfactory precipitations are not uncommon. As a result of these representations, however, the author visited several plants at work in the Transvaal, and noted that while at some few mines the precipitation was really excellent, at others the effluent, after treatment, was much too high in bullion-contents. An investigation into the causes of these unsatisfactory results disclosed the fact that more attention to the close packing of the zinc-shavings in the extractor-compartments tended to improve the results, even with the most dilute solutions. The function of the zinc being one of surface, it stands to reason that a compartment well filled with zinc would be more effective than a half-filled one. Moreover, the quality of the zinc was inferior. This should be in long, tough, thin, light threads; light enough to ignite readily, and tough enough not to disintegrate easily into a slime. The coarse shavings too frequently employed appear to give the reverse of the best practice ; they are brittle, contain less surface, and take up more room. It is almost impossible to pack a compartment properly

Jan 1, 1898

By George B. Langford

ON THE QUESTION of postwar controls there are today three schools of though ; some advocate state control of everything the socialists ; second are those who advocate the removal of all governmental control over industry - the freedom of enterprise ideal ; and third are those who advocate a middle course - sufficient control to stabilize economic and industrial life, and to prevent violent fluctuations such as we saw in the interwar years. I advocate this third course. I firmly believe un free enterprise, but not in freedom of enterprise, or laissez faire, and there is a great and significant difference between these two.

Jan 1, 1944

On the following pages are abstracts of papers published by the Institute during the year 1934 as TECHNICAL PWLICATIONB, CONTRIBUTIONS, m bound volumes and in MINING AND METALLURGY. For abstracts of papers that appear In bound volumes in 1934 but that were published as TECHNICAL PWLICATIONS m 1932 or 1933, see the TRANSACTIONS for 1932 and the YEAR BOOK dated January, 1934. Many of the TECHNICAL PWLICATIONS have been reprinted In bound volumes Information regarding this disposition, and number of pages in each paper, may be found m the list beginning on page 92 Volume numbers are given as listed at the beginning of the index, page 99 The abstracts are grouped as follows:

Jan 1, 1935

By C. Norman Cochran, James L. Brandt

ALTHOUGH gas in aluminum and its effect on aluminum products have been the subject of a number of papers, not many quantitative determinations of the hydrogen content of solid aluminum and its alloys have been recorded in the literature. For solid aluminum samples, four investigators have reported hydrogen contents which appear reasonable compared with the hydrogen solubility of 0.7 ml per 100 g, STP, in molten aluminum at 660°C established by Ransley and Neufeld' and verified by Opie and Grant' and Ransley and Talbot. Sloman," who used a vacuum fusion procedure, reported the hydrogen content of some high purity aluminum as 0.66 ml per 100 g, STP. Griffith and Mallett, employing the tin fusion method, reported the internal hydrogen content of six different aluminum alloys as ranging from less than 0.1 ml per 100 g, STP, for 1100 alloy to 0.7 ml per 100 g, STP, for 4043 alloy (previously 43S, a 5 pct Si alloy). Eborall and Ransley," using a solid extraction of the gases at 600°C, reported hydrogen contents ranging from 0.1 ml per 100 g, STP, to 1 ml per 100 g, STP. Ransley and Talbot reported that several thousand analyses on 99.2 pct and higher purity aluminum as well as Duralumin type alloys indicated hydrogen contents ranging from 0.1 ml per 100 g, STP, to 0.5 ml per 100 g, STP.

Jan 1, 1957

By Robert F. Mehl, Dana W. Smith

It has been shown that quenched iron of high purity exhibits a Wid-manstiitten figure much resembling martensite in appearance.1 This figure exhibits a maximum of four directions of the surface traces that characterize it, suggesting that a Fc forms from y Fe in plates parallel to the (III), octahedral, planes in the y lattice. Because of this, and also beqause of the general similarity to the structural appearance of martensite and to the Widmanstatten figure obtaining in slowly cooled hypoeutectoid steels it has been suggested2 that the orientation relationships obtaining between the y and a phases in pure iron are identical with those demonstrated in martensite3 and in slowly cooled hypoeutectoid steels,4 and indeed that the crystallographic mechanism of formation of a Fe from y Fe is the basic mechanism determining the orientation relationships found in both martensite and in slowly cooled hypoeutectoid steels. This paper will present experimental evidence in support of this view. Experimental Technique The analysis of the crystallographic mechanism of transformation in pure metals is beset with special difficulties, though some information

Jan 1, 1934

THE Annual Fall Meeting held in Chicago in conjunction with the celebration of a Centennial of Engineering brought forth a round of field trips and symposiums which did much to add to the store of information of the 240 who registered for the gathering. Instead of a scattered program, technical papers were grouped together in organized symposiums, where the particular importance of each report was enhanced by presentation in context. Despite the heavy accent on technical papers and informative field trips, those attending the meeting had ample time to enjoy the benefits of a visit to Chicago. The AIME dinner dance was held at the Palmer House, in the Red Lacquer Room. The Chicago Section played host Friday evening at dinner. The MBD held four sessions at the meeting headquarters, the Palmer House, September 4 and 5. Featuring the meetings was a review of taconite concentration and new theories on comminution. The first session opened with a paper on the Structural Features Which Effect the Concentration of Iron Formations, presented by F. J. Tolonen. The paper was centered upon the various members of the low grade iron formations of the separate Michigan districts. The study correlated macrostructure, microstructure, and concentration tests. [ ] Beneficiation Characteristics of Michigan Low Grade Iron Ores, presented by F. X. Tartaron, cochairman of the session, reviewed the work of his laboratory on the beneficiation of low grade ore taken from various strata of a deep shaft on the Marquette Range. The paper included data on flotation, gravity separation, magnetic separation, and combinations of these processes. The economics of low grade ore treatment generated great interest. Ty. Maki offered a compilation and correlation of field results with magnetic separators in ferrosilicon and magnetite medium recovery circuits. Following the morning session, 130 persons attended a luncheon, followed by a brief business meeting. Later, a film illustrating the grinding, separation, and pelletizing steps investigated by the Mines Experiment Bureau, was presented by H. H. Wade. T. E. Ban, and L. J. Erck gave a report on pelletizing which evoked much discussion. R. A. Limons presented a paper on the Mineralogy of Blast Furnace Sinter, for its author, H. M. Kraner. Friday sessions featured a new hypothesis for high speed drill rod milling and a new technical approach to comminution. Jack Myers commented that Consolidated's large rod mill was a hammer mill turned inside out. Steve Erickson described the use of Cyclones for Heavy Media Concentration of Iron Ore Fines. Bob Meaders gave a Progress Report on the Aerofall Mill. Shiou-Chuan Sun described an improved high frequency analyzer for studying the conductivity of suspensions of various minerals. L. A. Roe discussed a magnetic reflux condensor which enabled him to determine the degree of liberation of magnetic iron ores. Roy A. Johnson described a function of the hydroscilator in which the fan rake was eliminated in favor of a conical bottom. The Industrial Minerals Division sessions held September 5 and 6 and were well attended. The Friday morning session was particularly concerned with developments and advances in industrial minerals with special emphasis on the Chicago area. The first two papers dealt with transportation on the Great Lakes and fuel movement into the Chicago area. The third paper proved to be of great interest, turning the spotlight on the fairly new hydraulic mining methods introduced by a silica company in the Ottawa, Ill. field.

Jan 1, 1952

By A. A. Burr, D. G. Ebeling

The effects of casting texture, grain orientation and grain size upon the performance of Alnico permanent magnets is described. Single-crystal specimens were produced by special sintering and grain coarsening techniques to study the effect of crystal orientation. In addition to texture and orientation effects, an analysis of the results indicates that the permanent magnet performance is impaired by a refinement of the grain size. AN excellent historical review of the development of Alnico permanent magnets has been prepared by Bozorth.1 The desirable permanent magnet characteristics of Fe-Ni-A1 alloys were discovered in 1932 by Mishima.2,3 The work of Ruder' showed that the alloys were age-hardenable, and Betteridge5 defined the best composition and heat treatment for the magnetically isotropic alloy known as "Alnico 3." Horsburgh and Tetley0 increased the energy product by the addition of cobalt and copper, "Alnico 2," and Oliver and Sheddon7 demonstrated that cooling in a magnetic field improved the residual induction of this alloy. Jonas8,9 then disclosed the great practical benefits of heat treating an alloy of higher cobalt content in a magnetic field and the resulting alloy, "Alnico 5," has become the standard of the industry. This paper describes the fundamental aspects of a procedure which can be used to further improve the properties of these anisotropic permanent magnet alloys. A study of the casting techniques used in the production of anisotropic Alnico permanent magnets indicated that the magnetic quality was affected by the as-cast macrostructure. Improved performance was observed in magnets containing a high percentage of columnar grains whose long axes were parallel to the magnetic axis of the casting. McCaig10 studied the effect of such columnar grain structures upon the magnetostriction characteristics of similar alloys, however no data was presented showing the effects on other magnetic properties. The following paragraphs describe two experiments which were conducted to determine the effect of various grain orientations upon the energy product. Special composite molds were prepared of highly conductive and highly refractive components to remove the heat of solidification from the casting in a controlled manner. Representative macrostructures produced by these techniques are shown in Fig. 1, along with the relative volumes of favorably oriented columnar grains. The alloy, Alnico 5, has the highest permanent magnet performance of any commercial magnet material. It has the nominal weight composition of 8 pct Al, 14 pct Ni, 24 pct Co, 3 pct Cu, and 51 pct Fe. A heat of this material was cast into molds producing the type A and B grain structures shown in Fig. 1 and pairs of the resulting magnets were placed in heat-treating boats so as to eliminate any biasing effects of boat position. After a standard heat treatment the type A magnets, with 16 pct of the volume composed of favorably aligned grains, had a maximum energy value of 3,940,000 gauss-oersteds, while the type B magnets with 73 pct aligned grains averaged 5,090,000. This large im-

Jan 1, 1954

By J. Greenspan

The anisotropy of fracture and slip, that is, the brittleness and ductility of the beryllium single crystal, is characteristic also of po1ycrystalline beryllium in which the grains are oriented in a preferred manner. Beryllium with grain orientations resulting from hot working either unidirectionally or bidirectionally is ductile or brittle in directions given by the anisotropy and orientation of the grains. Textures developed from various hot-working sequences are given, and tensile results are correlated with textures. Not only texture, but fine grain size is necessary for obtaining high tensile elongation. Ultimate tensile strength and elongation are both correlated with grain diameter. Of particular interest is the case in which unusually high tensile elongations of 30 to 40 pct are obtained when basal planes are oriented to carry THE beryllium crystal (of nominal purity) is probably unique among metals with respect to its unusually acute anisotropy of slip and fracture. While extensive slip can occur on the system (1010) [ll20] starting at about 19,000 psi, the (0001) plane is particularly vulnerable to fracture at 4500 psi or less. Fracture occurs also on the (11zo) plane at about 26,000 psi.1"3 Further, there seems to be no other slip System which contributes significantly to

Jan 1, 1960

Jan 1, 1951

By Howard N. Eavenson

TWO months ago, just after the coal code hearing in Washington, one of our leading liberal weeklies printed a study of the coal industry made by an economist in the Administration, and on the outside cover bad it featured as "Coal-A Dying Industry." There are, of course, different opinions as to the accuracy of this characterization and I want to present some of the facts about the outlook for the bituminous industry for a short time ahead. In view of what has happened in the industry within the recent past it would be futile to attempt to make any prophecy about what is likely to occur in the future. We all know that a prophet is not without honor save in his own country, but it is likely that anyone undertaking this role about this industry would soon find himself in no man's land. One can, with some slight degree of safety perhaps, outline present conditions and tendencies and draw some inferences as to what the future may hold.

Jan 1, 1933

By C. E. Lesher

Two processes for agglomerating fine sized ores with low temperature coke are described. One process (Orcarb) agglomerates ores with limited amounts of carbon; the other (ore-carbon pellets) pelletizes fine sized ores, using low temperature cokes as the binder. Data are presented on the products obtained when taconite, magnetite, and hematite concentrates and several titanium oxide ores were used. REDUCTION of finely divided oxide ores has long been a major metallurgical problem. Various methods of agglomerating, notably briquetting, sintering, nodulizing, and pelletizing, have been developed and are in industrial use. Carbon is the usual reducing agent for oxide ores and attempts have been made to agglomerate fine ores with coking coal in order to get the metallurgical advantages of intimate contact and increased particle sizes suitable for subsequent smelting or reduction.1-3 For the past three years, research has been in progress on two processes for combining fine sized ores with reactive carbon in the form of low temperature coke. By one process, designated Orcarb, the ore is coated with coke carbon in amounts limited to that required for reduction and the result is an appreciable but limited increase in product particle size over that of the original ore. The second process, called ore-carbon pellets, produces pellets of fine ore bound by low temperature coke. The first objective was to develop a process for combining an oxide ore with only enough carbon for its reduction, the amount being that derived from the simple reduction equations. The carbon (that amount theoretically required for the reduction of the oxides in an agglomerate with ore), calculated to CO, ranges from 10 pct for zinc calcines or phosphate ores to 21 pct for rutile and 26 pct for silica. The carbon required for reducing iron oxides falls between the extremes—10 and 26 pct. When the carbon in the agglomerate is low temperature coke, reduction by hydrogen may be expected to take place, thus modifying the calculated carbon require- ment. On the other hand, in practice, an excess of reducing agent over that required in theory is normally used. Screen sizes of three iron ores on which the greater part of the experimental work was performed are given in Table I. Most of the testing was done with Freeport (Renton Mine) coal, but Pittsburgh and Elkhorn bed coals were also used. The first objective was to agglomerate the ore with sufficient low temperature coke to provide carbon for reduction, i.e., in the range from 10 to 25 pct. This was accomplished by preheating the ore, mixing with pulverized coking coal, and completing the coal carbonization in a plain steel rotating retort. The pilot retort, as it is now constituted, is shown by diagram in Fig. 1 and photograph, Fig. 2. Ore is fed into the upper kiln by a screw; it is heated to 900" to 1100°F by direct flame and it is then discharged into an insulating hopper from which it goes

Jan 1, 1956

R. F. McELVENNY.- Mr. Oldright has just given me a letter to read to you, which I think it may be of interest. It is headed, "Silver Meeting Dinner". The letter is as follows: "To Members of the A. I. M. & M E.: The annual business meeting and election of officers will take place at the University Club, Wednesday, May 28th, 1930 at 7 p.m., at the Silver Meeting Dinner. The Nominating. Committee for next year's officers have proposed the following names: Chairman, Robert Wallace; Vice-Chairman, G. W. Crane; secretary, C. T. Van Winkle, Other nominations can be made at the meeting. Utah being the leading silver producer of the United States, constructive suggestions regarding the silver situation will be made at this meeting which are new and of general interest to the members. The speak¬ers will be followed by a Round Table discussion of the silver situation and proposed remedies. Speakers will be - W. M. Ferry, President of the Silver Producers' Association, 'Recent developments in the Silver Question'.. Senator Frank J. Cannon, 'The Cannon Plan'. George W. Snyder, 'The Manufacture of Sterling Silver.' Discussion by J. J. Beason, G. W. Crane, J. 0. Elton, J. W. Wade and others. Members of the Conference on Copper Reverberatory Smelting are invited to be present. Chairman J. A. Norden will preside. C. T. Van Winkle, Secretary. Dinner will be $1.50 per plate." The next subject is "Boilers: Proper construction of, so as to secure best utilization of heat from gases, and facility in removing dust and clinker with minimum losses in operation." Who is particularly interested in that subject? The type of boilers is practically a standard practice now. I do not know of anybody that is using the tandem system now. No one is building a plant with a tandem system in it.

Jan 1, 1930

By C. E. Lesher

Two processes for agglomerating fine sized ores with low temperature coke are described. One process (Orcarb) agglomerates ores with limited amounts of carbon; the other (ore-carbon pellets) pelletizes fine sized ores, using low temperature cokes as the binder. Data are presented on the products obtained when taconite, magnetite, and hematite concentrates and several titanium oxide ores were used. REDUCTION of finely divided oxide ores has long been a major metallurgical problem. Various methods of agglomerating, notably briquetting, sintering, nodulizing, and pelletizing, have been developed and are in industrial use. Carbon is the usual reducing agent for oxide ores and attempts have been made to agglomerate fine ores with coking coal in order to get the metallurgical advantages of intimate contact and increased particle sizes suitable for subsequent smelting or reduction.1-3 For the past three years, research has been in progress on two processes for combining fine sized ores with reactive carbon in the form of low temperature coke. By one process, designated Orcarb, the ore is coated with coke carbon in amounts limited to that required for reduction and the result is an appreciable but limited increase in product particle size over that of the original ore. The second process, called ore-carbon pellets, produces pellets of fine ore bound by low temperature coke. The first objective was to develop a process for combining an oxide ore with only enough carbon for its reduction, the amount being that derived from the simple reduction equations. The carbon (that amount theoretically required for the reduction of the oxides in an agglomerate with ore), calculated to CO, ranges from 10 pct for zinc calcines Or phosphate Ores to 21 pct for rutile and 26 pct for silica. The carbon required for reducing iron oxides falls between the extremes—10 and 26 pet' When the carbon in the agglomerate is low temperature coke, reduction by hydrogen may be expected to take place, thus modifying the calculated carbon require- ment. On the other hand, in practice, an excess of reducing agent over that required in theory is normally used. Screen sizes of three iron ores on which the greater part of the experimental work was performed are given in Table I. Most of the testing was done with Freeport (Renton Mine) coal, but Pittsburgh and Elkhorn bed coals were also used. The first objective was to agglomerate the ore with sufficient low temperature coke to provide carbon for reduction, i.e., in the range from 10 to 25 pct. This was accomplished by preheating the ore, mixing with pulverized coking coal, and completing the coal carbonization in a plain steel rotating retort. The pilot retort, as it is now constituted, is shown by diagram in Fig. 1 and photograph, Fig. 2. Ore is fed into the upper kiln by a screw; it is heated to 900° to 1100°F by direct flame and it is then discharged into an insulating hopper from which it goes

Jan 1, 1956

By J. Burns Read

IT IS the purpose of this paper to summarize, as far as possible, the metallurgical information and experience gained by the Ordnance Department, during the War, in the manufacture of artillery cartridge cases, to describe the tests to which artillery cartridge cases were put, and to summarize the knowledge and experience gained in this testing. The authors wish to acknowledge the aid given by manufacturers, army officers, and civilian employees of the Ordnance Department in obtaining these data. Artillery cartridge cases are cold drawn from circular disks punched from strips of rolled brass. The manufacture involves from 25 to 30 main operations, which are done almost entirely on a punch press. Descriptions of the operations have appeared in various periodicals and, therefore, will not be given here. After each cupping, or drawing, operation, except the last, the cases are annealed at from 540° to 650° C. (1000° to 1200°F.), to remove all the hardening stresses set up in the metal and to allow complete recrystallization. After each annealing, the cases are pickled in niter cake or sulfuric-acid solution and then washed in water to remove all traces of acid. In some instances, the cases are then immersed in a cyanide-salt solution, and afterwards rinsed in water, to remove the thin layer of copper that forms on the surface of the cases during the acid pickle. The last cold-drawing operation is followed, by the heading operation which, by flattening the head of the case on the outside, causes the metal to flow on the inside to approximately the proper finished dimensions. The mouth, or open end, is then annealed at 430° to 480° C. (800° to 900° F.) by immersion in a salt bath or by gas flames. After being washed, the cases are tapered, when they are ready for machining, inspection, and testing.

Jan 4, 1922

By John V. Beall

During the last quarter of 1948, two new machines, which may revolutionize the coal mining industry, made their first public appearance within two months of each other. Both are designed to mine and load coal continuously. On Oct. 27, the "Colmol," invented by C. H. Snyder and A. E. Lamm, president and executive vice-president, respectively, of the Sunnyhill Coal Co., was demonstrated at the No. 8 mine of that Company at New Lexington, Ohio. The "Joy Continuous Miner," invented by H. F. Silver, president of the Silver Engineering Works, Denver, and developed and manufactured by the Joy Manufacturing Co., was demonstrated at the Mathies mine, near Finleyville, Pa., in the Pittsburgh coal seam.

Jan 1, 1949