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By Irving Lipkowitz

While the light metals are recognized generally as a distinct group in technical literature, economic classifications and data usually still treat them as part of the nonferrous group of metals. However, the economic characteristics of the light metals also differ markedly from those of other nonferrous metals. The distinctiveness of the light metals, as, a group and individually, becomes evident when their growth, since World War II is compared with that of other metals, as in Table 14.3.1. The growth of light-metals production has been much sharper than that of other metals. A weighted average for the light metals shows an increase of 112% during the 1958 to 1968 period. This compares with a 62% increase in the "All Primary Metals" component of the Federal Reserve Board Index of Industrial Production. The contrast was even sharper during the next six years (1968-1974), with light metals production up another 50% as against a 21 % increase in the FRB Primary Metals production index. The most important reason, however, for considering light metals separately is the trend and pace of technological change and not their distinctive statistics. Technology both creates and demands increasingly sophisticated materials. As technology advances and as all the world makes more extensive use of advanced technology, the importance of the light metals is likely to accelerate rapidly. There may be a profound clue to the future in the fact that light metals were predominant among the materials used in the construction of the Apollo 11 spacecraft. In determining what materials to use for the spacecraft and its equipment, the National Aeronautics and Space Administration (NASA) has explained that it did not look to "some of the more exotic metals" and relied instead on "generally proven materials." Accordingly, it apparently used a wide variety of metals, including precious metals, rare earths, special steels, copper, and light metals. What seems particularly significant is that, in seeking performance, NASA relied as heavily as it did on the light metals. Materials breakdown estimates show that aluminum accounted for over 75% of the materials used, titanium for another 5%, and magnesium was also used. Thus, light metals accounted for over 80%' of the materials used for the Apollo 11 spacecraft. The light metals are also unique in their availability. They rank high in abundance among the elements in the earth's crust. Aluminum is the third most abundant element, after oxygen and silicon, with magnesium ranking eighth, and titanium ninth. Among the structural metals, aluminum is the most abundant in the earth's crust, iron is second, magnesium third, and titanium fourth. This potential availability of light metals provides strong incentives for continuing improvements in process technology, because of two major national problems: (1) there is

Jan 1, 1976

By J. C. Wynn

This paper outlines research conducted by the US Geological Survey on the geophysical signatures of chromite. Results of the chromite study highlight the importance of a laboratory research Phase (petrophysical and petrographic studies) at the beginning of work on a new commodity; a realistic ore deposition model to serve as a conceptual framework, and the necessity to continually test, refine, and modify it during the study; and indirect geologic/geochemical indicators, secondary associations, and the use of multiple physical properties. The keystone to the success of the study is frequent and substantive dialogue among geologists, geophysicists, and geochemists.

Jan 1, 1984

By F. N. Pease, C. B. Dudley

Those who have worked a good deal on the chemistry of pig-irons of which the physical properties were known, cannot fail to have been struck by the remarkable want of relation between the physical properties of different samples, and the ultimate chemical composition. It is very well known among foundrymen that irons which will give say 4 inch of chill, and are, therefore, approximately the same in chemical composition, are very far apart, many times, in their physical properties. The foundryman's tests for strength are, of

Jan 1, 1886

By Wayne Anderson

Regarding the technical paper by Thomas E. Finch and Edward L. Fidler, "Recovery of Stray (Thin) Seams in Western Coal Mining." I would like to comment on this subject. In western Canada, most strip mines encounter thin seam coal or rider seams. Although the paper addresses the problems and costs associated with the recovery of this coal, it does not take into account what the savings are. Without looking at the savings, the "Total Objective" is of course not clear. I feel that in a stripping operation the mine can spend per ton (of the thin seam) up to their dragline stripping costs per ton to recover a rider seam or thin seam. The reasoning behind this is simply that this is the price the mine will have to pay to expose an equivalent amount of coal without the recovery of these thin seams. If the mine can recover a rider seam or thin seam for less than the dragline operating costs per ton, a savings will be realized. By recovering a thin seam or rider seam, the life of an ore body is extended by that amount of coal not thrown away. In addition, the cost of land acquisition, associated permits, capital, and reclamation will be reduced as more coal is delivered for a given area. When the above points are considered, the recovery of these thin seams can be very profitable and indeed worth recovering.

Jan 1, 1983

By L. J. Erck

H EAVY-MEDIA separation continues to be the favored process for concentrating the coarser fractions by elimination of undesirable tailing and middling fractions. The first vessel used for heavy-media separation was the closed-top cone. Further developments then led to the Akins spiral separator which fulfilled the requirements for improving metallurgica1 separation as well as gaining mechanical advantages. During the last season there has been a substantial influx of separator designs for further improvements of metallurgical separation based on the heavy- media method as well as attempting to garner further mechanical advantages with reduction in power consumption to boot. The newest of these designs was the Hardinge counter-current separator which was introduced into the field last spring in two plants. Both Hardinge separators proved satisfactory in operation and substantiat-

Jan 1, 1950

By T. A. O’Hara

SINCE May 1948, when tungsten carbide bits were introduced at the Flin Flon mine, they have been popular with the miners because of their fast drilling speed and low gage loss. The high cost of commercial carbide bits and tipped drill steel, however, prevented their use except for the hardest rock. In an effort to extend the use of tungsten carbide on a basis economically competitive with detachable steel bits, experimental work was begun in 1950 to test the feasibility of making tungsten carbide tipped drill steel in the mine drill steel shop. This work showed that tipped drill steel could be made locally at less than half the cost of the commercial product. The performance of the local tipped drill steel was comparable to that obtained with commercial carbide bits and tipped drill steel and the cost per foot drilled was much lower.

Jan 3, 1954

By Norman Weiss

Most papers on xanthate have dealt with principles rather than practice. On the assumption that many millmen are interested in knowing where and in what manner the xanthates are being used in mills other than their own, this paper will summarize the results of a recent survey of North American plants. A brief background story and a description of the xanthates will be followed with the results of that survey; then a few observations will be made on storage, feeding, and ore testing. The first xanthate was made in 1822 by Zeise of the University of Copenhagen. With commendable scientific detachment (or perhaps a bad cold) Zeise ignored a more pervading quality of the substance and named it for its color, after the Greek word "xanthos," meaning yellow. During the first 80 years of its recorded existence xanthate found use only in small quantity as an insecticide; after the turn of the century there was some further demand for it in the vulcanization of rubber. It was not until 1922, by coincidence the centennial of Zeise's discovery, that C. H. Keller of San Francisco, seeking sul-phidizing agents, recalled xanthate in connection with his experience years earlier when he had seen this material used in Europe to combat grape phylloxera. His successful tests with the new flotation reagent culminated in the basic xanthate patent (U. S. 1,554,216) in 1925. In the minds of many metallurgists the introduction of xanthate as a flotation reagent is identified with the beginnings of alkaline circuits, the first use of chemical collectors, and the beginning of selective flotation. Actually, these preceded xanthate by a number of years. The alkaline circuit in lead-zinc flotation was introduced by Lyster as early as 1912. In 1922 Sheridan and Griswold made their momentous discovery (Timber Butte) that alkali cyanides and zinc sulphate effectively inhibited the flotation of pyrite and sphalerite in pulps made alkaline with sodium carbonate or bicarbonate. The use of lime to retard pyrite in copper flotation began within two years after Ralston directed attention to its possibilities in 1917. These were the beginnings of modern selective flotation, which was practiced successfully on copper-iron ores at Nacozari in 1922, and at Inspiration, Cananea, and others only shortly afterward. In the lead-zinc mills, selective flotation was of even greater economic importance at that time. The Sunnyside plant of U. S. Smelting, Refining, and Mining Co. used the process earlier than 1920, and Consolidated, Timber Butte, and others soon followed. As a chemical collector xanthate was relatively a latecomer, for the Corliss patent of 1917 covered the first of these, alpha-naphthylamine, and the Perkins patent of 1919 the second, thiocarbanilid. Both of these were in extensive use before Keller's xanthate made its commercial debut in 1923. There is general agreement, nonetheless, that the introduction of xanthate was

Jan 1, 1949

By Russell G. Wayland

This paper gives the author's personal idea of the general viewpoint of the world's largest mica consumer, the U. S. Army, toward the supply, uses, and conservation of mica. However, to cover so broad a subject in a brief paper will require the dismissal of many phases with little or no mention. For example, it will be necessary to omit further reference to phlogopite or amber mica, even though amber block and splittings for certain spark plugs and commutator segments present some supply problems. This paper will deal entirely with muscovite, or white mica. Muscovite Mica Muscovite mica is available commercially in four general forms; namely, as block mica, as splittings, as washer punch, and as scrap mica.1 No strategic importance is attached to washer punch and scrap mica, even though scrap has found some use in military construction and in electrical ceramics. The use of washer punch as such has fallen off with the non-manufacture of household electrical appliances. Some qualities of block mica are also of little or no interest, but other qualities of block mica and all splittings are considered of vital importance. Army equipment requires large amounts of muscovite mica splittings in the form of built-up mica commutator segments and coil insulation in motors and generators. Other military items using significant amounts of muscovite splittings are transformers, switchboards, and blasting apparatus. Flexible mica tape, made from bookform or loose-dusted splittings cemented to paper, linen, glass cloth, and other backing, is widely used in coil insulation in heavy electrical equipment and in aircraft generators. All muscovite mica splittings come from India, principally because of the enormous amount of hand labor required in their preparation. In this emergency, the need for them was anticipated and large industry and government stocks were on hand, while shipments have continued to come by sea in spite of wartime hazards. With the possible exception of certain bookform splittings, no trouble is anticipated in supply. Accordingly, the remainder of this paper is devoted to block (or sheet) muscovite mica, including condenser film that is split from block. The Mica Problem Block muscovite mica is commercially classified into the following general qualitie3, beginning with the best quality: 1. Clear and Slightly Stained (C & SS). 2. Fair stained (FS). 3. Good stained (GS). 4. stained (s). 5. Heavy Stained (HS). 6. Black spotted. The ratio of relative commercial abundance in the present new supply of these micas is approximately 1 C & SS to 4 FS to ro GS to 14 S to whatever the

Jan 1, 1948

By Russell G. Wayland

This paper gives the author's personal idea of the general viewpoint of the world's largest mica consumer, the U. S. Army, toward the supply, uses, and conservation of mica. However, to cover so broad a subject in a brief paper will require the dismissal of many phases with little or no mention. For example, it will be necessary to omit further reference to phlogopite or amber mica, even though amber block and splittings for certain spark plugs and commutator segments present some supply problems. This paper will deal entirely with muscovite, or white mica. Muscovite Mica Muscovite mica is available commercially in four general forms; namely, as block mica, as splittings, as washer punch, and as scrap mica.1 No strategic importance is attached to washer punch and scrap mica, even though scrap has found some use in military construction and in electrical ceramics. The use of washer punch as such has fallen off with the non-manufacture of household electrical appliances. Some qualities of block mica are also of little or no interest, but other qualities of block mica and all splittings are considered of vital importance. Army equipment requires large amounts of muscovite mica splittings in the form of built-up mica commutator segments and coil insulation in motors and generators. Other military items using significant amounts of muscovite splittings are transformers, switchboards, and blasting apparatus. Flexible mica tape, made from bookform or loose-dusted splittings cemented to paper, linen, glass cloth, and other backing, is widely used in coil insulation in heavy electrical equipment and in aircraft generators. All muscovite mica splittings come from India, principally because of the enormous amount of hand labor required in their preparation. In this emergency, the need for them was anticipated and large industry and government stocks were on hand, while shipments have continued to come by sea in spite of wartime hazards. With the possible exception of certain bookform splittings, no trouble is anticipated in supply. Accordingly, the remainder of this paper is devoted to block (or sheet) muscovite mica, including condenser film that is split from block. The Mica Problem Block muscovite mica is commercially classified into the following general qualitie3, beginning with the best quality: 1. Clear and Slightly Stained (C & SS). 2. Fair stained (FS). 3. Good stained (GS). 4. stained (s). 5. Heavy Stained (HS). 6. Black spotted. The ratio of relative commercial abundance in the present new supply of these micas is approximately 1 C & SS to 4 FS to ro GS to 14 S to whatever the

Jan 1, 1948

By O. O. Laudig

It is a well-established fact that some ores do not reduce as readily in the furnace as others, thus seriously affecting out-put, and consequently, cost of product. With the object of obtain ing some information upon this subject, the following experi ments were made in the laboratory of the Buffalo Furnace Company. Efforts were made to obtain, as nearly as possible, represent ative ores from some of the most important mining districts in the United States. The ores received were from the Mesabi, Marquette, Gogebic, Menominee and Vermilion ranges of the Lake Superior district and from Southwest Virginia. Requests

Jan 1, 1897

By C. C. Clark, J. R. Mihalisin, K. G. Carroll

OBSERVATIONS made in this paper were for the purpose of exploring the anomalous behavior of a particular heat of Type 310 stainless steel. The alloy, of nominal composition 25 pct Cr, 20 pct Ni, was observed to form a grain boundary precipitate at exceedingly high rates. A sheet of this metal, 0.060 in. thick, after cooling in air from 2000°F showed the presence of the grain boundary material, whereas none was found after water-quenching from the same temperature. X-ray techniques were applied without success and, in view of the ex-

Jan 1, 1958

By AIME AIME

WITH a membership in the Institute of 32 years behind him, Chester Alan Fulton became an A.I.M.E. Director last month. In 1937 he served as Chairman of the Industrial Minerals Division. Mr. Fulton was born in Brooklyn on Dec. 18, 1853, and at the age of 22 graduated from the Columbia School of Mines. His first job was as assayer for the Standard Smelting Co., Rapid City, S. D., but he soon left to become shift boss in the cyanide plant of the Peregrina Mining & Milling Co., Guanajuato, Mexico. From 1908 to 1912 he was mine superintendent of the Guanajuato Mining & Milling Co., leaving there for two years of varied professional work. From 1914 to 1916 he was

Jan 1, 1939

By F. W. McNair

WITHIN the last twenty-five or thirty years the actual operations of the great mining industry have passed almost wholly under the charge of men trained in the technical colleges. It follows that the industry is profoundly influenced for good or ill by the character of the training which the college graduate receives, and the relations existing between the industry and the colleges. This fact seems to be generally recognized, as evidenced, for example, by the existence of a Committee on Technical Education created some two or three years ago by the Mining and Metallurgical Society of America. In 1921 this committee rendered a very able and. extremely well poised reports of technical education as applied to the prospective mining engineer. It deserves the attention of every one interested in the effectiveness of engineering training. That the importance of the relation between the mining industry and the engineering colleges is recog-nized is evidenced also by the mass of criticism, usually adverse, which is proffered to and often hurled at the colleges by those in the industry. The man inn the field sometimes goes so far as to say that engineering educa-tion is hopelessly inefficient and its product worthless, while the college worker sometimes complains that the demands of the industrialist are too numerous and conflicting to be met, and adds that they would' best be ignored. Between these extremes, there seems to be a general consensus of opinion that the training of the would-be engineer can be, and. ought to be, made much better than it now is.

Jan 4, 1923

By Lewis Stockett

During the year 1903, a building having machinery corresponding to ail anthracite-coal breaker was erected at the town of Stockett, Cascade county, Mont., for the purpose of breaking-up and cleaning bituminous coal. The coal is mined from a vein of the Kootenai group of the Lower Cretaceous measures having the following section: The vein is nearly horizontal in position, and each bench differs in quality as shown in Table I.

Jan 1, 1905

By C. L. Siebenthal

C. E. SIEBENTHAL, ? Washington, D. C.-From being one of the most maligned of metals-a veritable bugaboo-cadmium has almost overnight become respectable, though its slender claim to respectability rests almost wholly on the possibility of its substitution for tin. Preliminary to any campaign for such substitution, particularly for enforced substitution, the possible supply of cadmium should he determined as closely as possible; for that reason the statistical inquiry of which this paper embodies the results was undertaken. Production Cadmium is marketed in two forms, as metallic cadmium, in sticks or bars, and as cadmium sulfide, the pigment. The metal has found its greatest field of use in this country as a component of an easily fusible alloy that is used in automatic fire extinguishers. The sulfide is .used to some extent in paints but chiefly to give color and luster to glass and porcelain. The metal was first made in this country by the Grasselli Chemical

Jan 12, 1918

By R. H. Frank

IN the investigation of the effect of the time of heat on slag volume, no attempt was made to vary the usual practice at the Bonney-Floyd Co., such as selecting special-purchase scrap or cleaning foundry returns. The data were collected from seven normal heats, including four medium carbon, two medium manganese-molybdenum and one nickel-chrome-molybdenum. These heats were made with our normal practice and no special instructions were given the melters except to make sure that all slag-making materials were weighed and that no slag was lost during the melting, refining or tapping. After the stopper was set in the ladle, it was carefully weighed and the heat was tapped. As soon as the heat was slagged on the pouring floor, the nozzle was plugged with mud, to preclude the possibility of losing any slag while the ladle was being conveyed to the scales. The ladle, containing all of the slag, was weighed and the difference between this weight and the original weight was taken as the slag weight.

Jan 1, 1947

By A. L. Holley

THERE is a growing demand for pure and cheap material for fine open-hearth steel ; a material not only very free from phosphorus, but from carbon and silicon; so that it may he rapidly converted into steel. Iron and steel scrap are not trustworthy as to quality, and they are often dear. There are three methods of purifying cheap materials for the open hearth. 1. Mechanical puddling, as done at Creusot, which removes 90' per cent. of the phosphorus from the pig iron. 2. Krupp's washing process (the conduct and results of which I fully described in a former paper*), which eliminates 70 to 80 per cent. of the phosphorus and most of the sulphur and silicon from pig iron. Neither of these processes would sufficiently purify, for very fine steel, those very impure pigs which are cheapest in many parts of the United States: 3. The process of producing directly from the ore an iron which is practically pure chemically, although mechanically mixed with the impurities of the ore. This is the oldest of iron processes ; one form of it, the Catalan forge, employed to produce charcoal blooms, is still in use, but its great cost is rapidly throwing it out of competition. Among the modern attempts to produce iron direct from the one, on a large scale and at a cheap rate, several have been in various respects successful. Dr. Siemens's process of treating a ton and a half or more of ore and the coal to deoxidize it, in a rotating gas furnace, and bringing out, in some four hours, a ball of chemically pure iron so soft that the fluid and impure slag may be squeezed out of it, is the most attractive and the most highly developed of all the modern direct processes. I have watched it, from time to time, since 1874, and have noted a steady improvement. It may now be said to have passed the experimental stage, although, like older processes, it must be adapted by practice to special materials. The cause which has been more potent than all others, including the defects of the best direct processes, to bring these processes into disrepute, is the waste-ful treatment of the direct product. With one or two exceptions (when failure was due to other and obvious causes), the direct product has been made into wrought iron (weld iron). Even Dr. Siemens has, at Towcester, in England, and at Park, Bro. & Co.'s, in Pittsburg, set up his apparatus for this purpose. Is it likely that

Jan 1, 1880

The President was authorized to appoint. a liaison committee to cooperate with the American Mining Congress in respect to the establishment of a Secretary of Mines and Mining in the President's Cabinet. He appointed Edwin Ludlow, Chairman; Mark L. Requa, and J. E. Johnson, Jr. It was resolved to accept the invitation from the Chicago Section to hold the. 120th meeting of the Institute in Chicago during the week of Sept. 15, 1919. The action of the Executive Committee in appointing Past President E. Gybbon Spilsbury as representative of this Institute to visit France upon the invitation of the Société des Ingénieurs Civils de France was approved. The final budget for 1918 was approved. Tile President was authorized to appoint a committee, of three members, on the Development of Activities of the Institute. The committee was requested to report at the February meeting of the Institute, and the Secretary was requested to invite each local section to have a member present to discuss the subject. The President appointed J. W. Richards, Chairman; P. N. Moore, and Allen H. Rogers. Thirty-six members, ten associates, and five junior associates were elected; one change of status from associate to member was granted; two members were reinstated; and eight resignations were accepted. An extension of time was granted to nine members. The dues of eight members were suspended on account of their being in active service.

Jan 2, 1919

By AIME AIME

DURING the morning session," on Feb. 17, papers were presented and discussed regarding a recent wire saw installation, cement rock quarry operations, hydration factors in gypsum deposits and the status of the phosphate industry of the West. Oliver Bolvles presided and there were about twenty-five members present. W. M. Weigel's paper (T. P. 262), "The Application of the Wire Saw in Marble Quarrying," was read by the author. He described the recent installation of the St. Clair Marble Co., near Guion, Ark. Since the use of the wire saw for quarrying is comparatively new and the fact that it has been almost entirely limited to slate quarries heretofore, ?he description and data given in this paper were of much interest.

Jan 1, 1930

By H. M. Howe

One of the little electric-resistance magnesia crucible-furnaces which I designed for the metallurgical laboratory of the School of Mines of Columbia University is shown, in vertical section, of full natural size, in Fig. 1. The furnace itself consists of two semi-cylinders of magnesia, A A, with a cover of magnesia, B B, and a stopper, C, also of magnesia, which is perforated to admit the leads x, y, of a thermo-electric couple. The furnace is heated by the spiral of platinum wire, D D (entering and departing by the openings I and K), through which a current of any desired strength is passed, bringing it to incandescence, and to ally temperature, not above the melting-point of platinum, which may be desired. The crucible E, actually used in this furnace, is also of magnesia. I have heard of some unsuccessful attempts with furuaces of this general class, and have attributed these failures to the use of siliceous materials for the furnace-walls. Of course such a result is what we should expect, since the silica mould readily be electrolysed by the current, and the resultant silicon would alloy with platinum ; but the little magnesia furnace here clescribed seems to be wholly free from this objection. It has been used in my laboratory for some months, and temperatures, up to 1100° C, hare been developed in it over considerable periods of time—indeed, it has been held near 1400" C. for about two hours—without indication, thus far, of any deterioration of the platinum. In the section shown, F F are a pair of steel disks, bound together, but separated by the inverted thermo-junction, N, of the thermo-electric pyrometer. This arrangement permits the observation and record of retardations in the heating and cooling of F F—in other words, the determinations of the cooling curves of steel—a purpose for which the furnace has been used, thus far, more frequently than in the determination of meltingpoints. For the latter operation, however, it is also suitable.

Jan 1, 1902