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By Sheldon P. Wimpfen

EVERYWHERE in mining circles the talk is of this new development of hard faced or insert bits which hints of many changes to come in mining practice and rock drill equipment. In the past fifteen years new equipment has appeared in rapid succession which brought one change after another in rock breaking practice. Detachable bits were an innovation which met with wide success. Blasthole diamond drilling has proven itself. Only recently, fusion piercing was announced as a possible solution to the problem of breaking taconite ores. For several years this interest in new methods has been growing and various experimental usages of tungsten carbides in rotary type rock drilling bits have been partially successful. American experts in rock drilling have been concerned with the subject for ten years but actual commercial practice was begun by European manufacturers and mining companies. At this time nearly every manufacturer of rock drilling bits is working on some type of an insert bit. On the Rand, European manufacturers are testing out various types of insert bits. The problems relating to rock drilling in South Africa vary greatly from ours. The bulk of the drilling there is limited to the 31/2-ft holes that are drilled for breaking the gold bearing reef ore. Rock drilling in most mines is far more diversified. Both drifting and ore breaking call for holes varying in length from 4 ft up to as much as 50 ft and more.

Jan 1, 1947

By Charles L. Elliot

Data for mining applications of geophysical activity in the Free World in 1963 has been collected by the Committee for Geophysical Activity of the Society of Exploration Geophysicists. This information has been made available to the AIME and is published here in abstract form with the kind permission of the SEG. The data is based or1 244 responses (51%) to the questionnaires circulated among 475 worldwide organizations engaged in mining geophysical operations and or research. It is believed that the data is a realistic appraisal of actual world geophysical activity.

Jan 8, 1964

By Arthur Braid

THE war has caused an increasing scarcity of phosphorus and its well known alloys with copper and tin. At the same time, the production of brass and bronze, nickel-silver, cupro-nickel, and other non-ferrous alloys, has considerably increased. The manufacturers of these products had therefore to secure other materials which would serve their purpose; principally that of a deoxidizer, which could be. obtained promptly and regularly. Fortunately these materials, pure carbon-free manganese metal and manganese-copper alloy, were not hard to find-in fact, they were never lost. Manganese in various forms has been used in Europe for more than a century; in this country, however, when manganese was first used, and indeed for a long time thereafter, it was consumed mainly in the- manufacture of manganese-bronze. Many foundrymen at that time used manganese-copper with the same freedom as phosphor-copper. Although iron enters into the composition of certain- grades of bronze, it is very detrimental to non-ferrous mixtures in general; consequently ferro-manganese is not applicable, and therefore pure manganese metal, or the alloy of manganese and copper, technically free from iron and other impurities, is now being generally used. The following are the principal elements having an affinity for oxygen: 1, Sodium. 2, Potassium. 3, Calcium. 4, Strontium. 5, Barium. 6, Magnesium. 7, Aluminum, 8, Phosphorus. 9, Silicon. 10, Manganese. 11, Iron. 12, Zinc. 13, Lead. Each metal has its natural flux, or deoxidizer, in the form of a metal or non-metal which will alloy with it, and has a strong affinity for oxygen. For example, phosphorus, as is well known, acts very beneficially in copper alloys that contain tin. Within 'the last few years, and particularly since the war began, the great value of manganese in nickel alloys has been demonstrated, and one by one the manufacturers of these products have adopted its use. While manganese has not so strong an affinity for oxygen as magnesium, aluminum, or silicon, it is nevertheless sufficiently powerful to reduce any oxide of nickel, copper, or zinc that may be present in the nickel alloy to be purified.

Jan 11, 1918

By Fredrick C. Kruger

Introduction This surprisingly little-known group of minerals, the nonmetallics, so-called for their lack of metallic luster, is the largest group of the mineral kingdom, and cinstitutes perhaps 75 percent of all mineral species. For the most part, these minerals are compounds of the common acids, oxides, hydroxides, and two elements, carbon and sulfur. The list of the non- metallic minerals, therefore, is very long. It includes the borates, carbonates, chlorides, fluorides, nitrates, phosphates, silicates, sulfates, and less commonly, arsenates, chromates, molybdates, suliides, tungstates, and vanadates, the latter groups, and many of the oxides, being sought principally for their metal content. Those nonmetallics used commercially are generally called the industrial minerals, although in addition this term also includes a considerable group of rocks. The list of industrial minerals and rocks is continually growing as new uses are found, and it now numbers over 300 commodities. The industrial minerals industry has developed since about 1920. There- fore, the development has been fast, and it has been more or less parallel with the development of the art of minerals beneficiation. General Discussion of the Group This group is so heterogeneous that it has defied logical, or widely accepted, classification, whether by origin, composition, or end use, and perhaps for this reason the industrial minerals generally have received short shrift in both teaching and research. Except for those involved with asbestos, cement, fertilizers, gypsum, salt, sand and gravel, few large companies have deigned to enter the field, and consequently most industrial minerals have been developed for the most part by the small operators or entrepreneurs. Yet surprisingly, except for one war year, the nonmetallics have always surpassed the metals in value and tonnage (Fig. 1). One main characteristic that most of the nonmetallics have in common is direct sensitivity to labor and transportation. In other words they are characterized by large bulk and low-unit value, and hence have what might be termed a "place value".

Jan 1, 1971

Jan 1, 1933

By B. G. Klugh

In a paper before the Institute at Wilkes-Barre, Pa., June, 1911,' Mr. James Gayley discussed the application of this process to iron-bearing materials. The same author² described the results of operations at the plant at Birdsboro, Pa. The purpose of the present paper is to present further discussion of some techuical details involved in the operation of this plant, and of the theoretical and practical relations of this product to blast-furnace practice. Since Oct. 1, 1911, the Birdsboro plant has been in operation at the blast-furnace of the E. & G. Brooke Iron Co. The results have been highly satisfactory, although the material treated, being chiefly the flue-dust currently made by the furnace or taker] from the accumulated stock-pile, was excessively high, and yet not uniform, in carbon, so that the desirable control or regularity of the amount of fuel in the mixture treated could not be maintained. Nothing could more forcibly demonstrate the flexibility of the process than the fact that, under these conditions, the sinter produced was, in all cases, of excellent quality. The Dwight & Lloyd process, as such, slid its present highly-developed mechanical appliances were described by Mr. Gayley in the paper above mentioned. While the repetition of some particulars will be unavoidable in this paper, it will be confined to features bearing upon the metallurgical principles involved. According to the principle of the process, the finely-divided iron-bearing material to be sinterecl is intimately nlixed with

Jan 1, 1913

By HAROLD VINTON COES

MANAGEMENT has been tersely defined as getting things done through the efforts of other people; but before we proceed further, let us distinguish between administration, management, and organization. Oliver Sheldon in his book, "The Philosophy of Management," offers the following definitions: Administration is the function in industry concerned in the determination of the corporate policy, the co-ordination of finance, production, and distribution, the settlement of the compass of the organization, and the ultimate control of the executive.

Jan 1, 1943

By SAM YOUR

PROCESSING, technology and application of non- ferrous metals-copper, lead, zinc, aluminum, nickel, precious metals, foundry metallurgy, less common metals, secondary metals-are the special field of the Institute of Metals Division. New developments in this field during 1930 are more or less briefly out- lined in this review prepared by the papers and publications committee of the Institute of Metals Division as follows:

Jan 1, 1931

By Michael Bradbury

INTRODUCTION A major change in financing exports in recent years has been the decreased importance of subsidized export credits, following the commitment of the OECD countries to eliminate the subsidy element. Subsidized export credit rates are now often more expensive than market rates as the financing for exporters has decreased in volume and importance. The forfait market, in recognition of this decreasing importance, provides a rapidly expanding source of nonrecource finance for exporters. The following is a step by step guide to what it is, how it works, its benefits and problems. WHAT IS FORFAITING? Forfaiting is not new. It has been used in Europe for about 25 years to provide export finance for both capital goods and commodities without recourse to the exporter. Although long the preserve of exporters in Germany, and more lately Italy, forfaiting is now used increasingly by exporters in Great Britain, the United States, Canada and Scandinavia. It is a fairly simple operation with easy straight-forward documentation. The transaction involves the purchase by the forfaiting bank of a bill of exchange or a series of bills without recourse to the exporter. These bills will have been drawn by the exporter, accepted by the importer, and will usually bear the unconditional guarantee of the importer's bank. They are normally drawn payable at intervals during the credit period agreed between importer and exporter and are purchased at a discount by the forfaiter. The exporter thus obtains his cash payment and the importer receives his credit period. The forfaiter collects the amount of the bills as they mature directly from the importer. Credit periods vary, depending upon the type of goods and the country and commercial risk of the importer. The period is generally between one and five years with six monthly maturities. The usual forfait currencies are US dollars. Deutschmarks and Swiss francs and others, such as sterling, French francs, and the Scandinavian currencies are being used more frequently. CHOOSING FORFAITING Most types of financing require the continued involvement of the exporter in the financial side of the transaction during the credit period. Forfaiting has certain comparative advantages. In particular, it is possible to forfait 100 percent of the risk without recourse to the exporter, unlike government sponsored export finance schemes, where some retention of the risk by the exporter is required. In addition, exports from country sources do not present problems and forfaiting can also cover trade within the EEC. Other benefits for the exporter are: (a) The exporter's balance sheet is improved; debts are turned into cash thus improving the liquidity of the company and enhancing its cash flow. And there are no contingent liabilities for bills of exchange. (b) If the sales contract is in a foreign currency forfaiting removes the risk to the exporter of adverse movements in foreign exchange during the credit period. (c) Fluctuations in interest rates during the credit period can be ignored since in forfaiting the transaction is usually done on fixed interest rate terms on a discount basis. (d) The political and transfer risks are taken by the forfaiter. (e) The commercial risk is taken by the forfaiter. (f) The costs of administration and collection etc. during the credit period are removed.

Jan 1, 1985

By Thomas H. Leggett

The conditions surrounding this mine are, perhaps, not sufficiently rare or significant to warrant special attention. A certain interest, however, attaches to the locality through the recent discovery of fossil cycads made there by Mr. Charles M. Rolker, of New York, who has repeatedly visited this district, fixing the geological horizon

Jan 1, 1889

[ ] TUNNELS TO BINS. Originally designed for tunnel work, the strong lightweight liner plates used to construct this 30-ft diameter, 31-ft high, aggregate storage bin have several advantages. Bins and conveyor to tunnels can be quickly erected in any season, for permanent service, or to be salvaged and reused. Armco Steel Corp. (16) ROLLER CHAIN: Engineering Data Book No. 2457 published by Link-Belt Co. is a comprehensive 148-page volume on roller chain and its application. Detailed engineering information covers installation, maintenance and lubrication of chains for drives, conveyors, and sprocket wheels. The book covers selection of drives to meet both standard and special installations. (17) LABORATORIES: The Fisher Scientific Co's. line of 21 basic units of standardized steel laboratory furniture is described in catalog no. 25. The Unitized line was designed to combine the advantages of custom installation with the convenience of selection, delivery and continued flexibility that goes with ready-made units. (18) PUMPS: Two similar, but functionally different types of vertical centrifugal wet-pit pumps; a heavy duty bilge pump for handling solids-free liquids and drainage; and a screenless sewage ejector, constructed to handle sewage and solids carrying liquid; are illustrated in a bulletin from Yeomans Bros. Co.

Jan 1, 1952

Jan 1, 1887

By L. W. Rowe, S. S. Cole

A laboratory bench scale unit is described whereby finely divided chlorinatable residues are held for a short period by a restraining bed of a coarse-grained ore of comparable composition to permit 'flash' chlorination of the high surface area powder. Results on chlorinating a finely divicled titania residue using rutile sand as the restraining bed showed that 92 pct utilization of chlorine and equivalent conversion of TiO2 in the fine residue to Ticl4 were attained with a dust loss of about 3 to 4 pct and an equivalent amount of ch1om'nation of the titanium values in the restraining bed. THE chlorination of coarse grain titaniferous ores; i.e., 20 to 150 mesh sizes in fluidized beds is practiced commercially.' One effective method found for the chlorination of a very fine material in a fluidized bed is the "flash" chlorination technique.' By charging the finely divided charge material into the bottom of an established bed of optimum sized rutile, ilmenite, titanium beneficiate, or even an inert material such as sand, chlorination occurs before the dust can pass through the bed. The major requirement is that the bed be less chlorinatable than the charge. In this process, the charge consists of a finely divided (between one and 50 µ) titania residue obtained from a titaniferous ore beneficiation process. The charge is blended with a 20 pct wt basis addition of 20 to 60 .mesh size low volatile coke (to minimize hydrogen chloride formation) and fed to the bottom of the bed with the chlorine gas stream. A ball check device is used to permit entry of the charge and prevent the bed from discharging when the gas flow is cut off. The coarse pieces of coke serve to reduce compaction in the charge mixture and permit sat]sfactory feeding without plugging or jamming. Feed and gas rates are adjusted to provide for complete reaction of the charge material, with 90 to 95 pct chlorine efficiency, and maintain a gas flow in the range of 0.4 to 0.6 ft per sec. The equipment consisted of a 3-in. diam mullite tube enclosed in an electric furnace. A bow-shaped 3/4 in. Saran tube fed the charge from an air lock type of feed hopper (to prevent the escape of the chlorine gas into feed bin) to the bottom of the bed. The charge rate was set by providing a small awiliary hopper below the feed hopper where a weighed portion of the charge could be discharged in a specified time interval into the main chlorine stream. The chlorine rate was measured by a flowmeter. The reaction tube was filled with a bed of Australian rutile ore, this restraining bed serving two purposes; i.e., it rapidly heated the fresh charge to the reaction temperature and retained the particles in the bed for a sufficient time for selective chlorination to proceed. Due to the fine particle size and open, porous structure of the charge, this reaction was almost instantaneous, and, with proper adjustment of feed and gas rates, very little fine material passed through the bed without reacting and only a very small fraction of the restraining bed was chlorinated. A typical reaction procedure was to fill the bench scale fluidized bed unit with a 1 kg charge of Australian rutile ore analyzing 95.5 pct TiO2, 0.6 pct FeO, a beach sand deposit 40 to 150 mesh size. When fluidized, the bed was approximately 2 ft in depth. The ore was fluidized with a 1:l mixture of chlorine and nitrogen at a rate of 0.40 ft per sec. This gas mixture was necessitated by the comparatively short bed depth; a larger unit, with a deeper bed, could be fluidized with chlorine alone without significant free chlorine loss. Feed rate was 8.0 g per min of beneficiated ilmenite analyzing 85.0 pct TiO2, 2.6 pct FeO plus 1.6 g per min of 20 to 60 mesh petroleum coke. The

Jan 1, 1962

[ ] (17) WORTHINGTON: Cartoonist-author Don Herold recently took a look at the Worthington Corp., putting the results into a compact booklet called "A lot of things beside pumps." The story is aimed to better acquaint you with Worthington and how they came to produce a diversified industrial equipment. (18) SPEED REDUCERS: Now available is Cleveland Worm & Gear Co.'s new general catalog. In its 180 pages are the illustrations and description of the complete Cleveland line, together with full engineering data, dimensions, weights and horsepower capacities of the various drives. (19) METAL PRODUCTS: Armco Drainage and Metal Products, Inc. has just published a condensed 6-page catalog of its products designed for mining use. It describes and illustrates such products as Flex-Beam guardrails, corrugated metal pipe, liner plates, retaining walls, Steelox buildings, and welded pipe. (20) RECORDS: Pre-scheduled, controlled, preventive maintenance reduces costly downtime to a minimum and eliminates the need for large emergency crews. A new folder describes how such a program can be accomplished by using Remington Rand Inc., Kardex visible records. Another Remington Rand Inc. bulletin is the certified case history of how Kardex visible purchasing records help maintain a smooth running purchasing department.

Jan 1, 1952

By E. A. Gulbransen, J. W. Hickman

ONE of the important factors that determine the resistance of a metal or alloy to further chemical reaction is the structure of the superficial oxide film A thorough understanding of the physical and chemical structure as well as the stability of the oxide film formed on the surface as a function of time and temperature of the chemical reaction might furnish clues as to the nature of the reaction process and the protective nature of the film A comprehensive program has been undertaken to study these phenomena This paper summarizes the structure of the oxide films formed on the metals iron, cobalt, nickel, chromium and copper at temperatures up to 700°C Before the introduction of the electron diffraction technique, it «as necessary to use either direct chemical analyses or X-ray diffraction analyses to determine the nature of the oxide film formed on the metal or alloy Chemical analyses yields information on the percentages of the several atomic species present in the film while X-ray diffraction analyses yield information on the atomic geometry In special cases the information obtained may be identical, but in general both view-points are necessary Much of, the early work was carried out on the oxidation of bulk samples where thick films were obtained The products were identified after cooling to room temperature by X-ray diffraction and chemical analyses Although much useful information has been obtained in this manner, little could be learned about the character of the protective oxides during the period when the films were actually protective Evidence concerning the chemical structure of thin oxide films has been made possible by the development of the electron diffraction reflection technique In this method the most fruitful investigations have been made by carrying out the reaction in situ at the temperature at which the film is actually protective LITERATURE The oxidation of iron has been extensively investigated by X-ray and electron diffraction Jackson and Quarrell1 found that oxide films formed and examined at the same temperature differed considerably from those allowed to cool to room temperature The results showed that below 400°C the oxide that was stable in intimate contact with iron was Fe304, between 515° and 900°C the stable film was FeO Above the upper change point of iron the oxide was found to be Fe304 prom 400° to 515°C , FeO, Fe304 or a mixture of the two oxides was found Recrystallization of the air-formed film below 400° and above 900°C led to the formation of Fe304 In the range where thicker films consisted of FeO, the air-formed film was converted to a new hexagonal oxide not previously described

Jan 1, 1946

By H. C. George

The Wisconsin Zinc District, or the Upper Mississippi Lead and Zinc District as it is often called, lies in the southwestern corner of Wisconsin, in Grant, Iowa and Lafayette Counties, and it includes adjoining parts of Illinois and Iowa. The district is about 70 miles long, north and south, and about 40 miles wide, east and west. It lies wholly within what is geologically known as the non-glaciated area of the Upper Mississippi Valley. HISTORY OF THE DISTRICT The district was first opened up as a lead producer in 1822. From this time until 1860, about 205,000 tons of cog lead (galena) and washed lead (galena) was produced from shallow crevices and openings. From 1860 to 1900, about 74,500 tons was produced, and since that time, from 5000 to 7000 tons has been produced annually. Since 1900, most of the lead concentrate produced has been as a byproduct of the zinc mines. The first zinc ores were mined about 1862. These were the carbonate ores, locally known as "drybone." Very little zinc blende was mined in the district, previous to 1875. The zinc blende ores mined from 1875 to 1900 were mostly of the high-grade, hand-cobbed, sheet-ore class, which usually contained from 45 to 60 per cent. metallic zinc Such mines as the "Sallie Waters," "Quinlin," 'Lead Mine," "Benton Blende," and "Ida Blende," located near Benton, Wis., were mines which produced ores of this type, during this period. The mines located at Highland, the "Coker Mine" located at Livingston, Wis., and the "Opencut Mine" located at Shullsburg, Wis., were mines that were heavy zinc carbonate producers, previous to 1900. The production of zinc ores in the district from 1862 to 1890 was about 283,500 tons, mostly zinc carbonate, with a probable average metallic zinc content of 30 per cent. From 1890 to 1903, the production

Jan 1, 1918

By Charles A. Thomson

RECENTLY a prominent Brazilian' doctor wrote to an American friend: "I feel that cultural relations between the American and Brazilian people could be promoted in a very speedy and effective way by establishing contacts between men of the same professions. . . . A Brazilian mechanical engineer could be immediately interested in relations with American colleagues, even if he had never heard of Longfellow and was not interested in Stokowski's orchestra. . . . A large number of cultural ties could be established between specific groups of men who have already some common interest, and who, whenever they meet, can do something that naturally brings them closer, that is, `talk shop."' In appointing a committee on Inter-American Engineering Relations to cooperate with the Department of State in its program of fostering cultural relations with the other republics of this hemisphere, the American Engineering Council has taken a step which should lead to a greater sense of unity and fraternity among engineers of the Americas. That such unity and fraternity are part and parcel of the moral defense of the hemisphere is obvious. For years engineers of the United States have been traveling South and South-east to construct roads and bridges, dam rivers, harness waterfalls, build ports, install and operate mining equipment, and erect buildings and plants, often at the risk of life. Those in the teaching profession in this country have had as pupils a growing number of students from our neighboring republics whom they have sent back home trained in the most efficient engineering methods. In a sense, however, these relations with the other nations on this side of the globe have been haphazard and left to chance. Personal acquaintance among engineers has played its role but no organized attempt appears to have been made to take advantage of the natural relationship which geographical and historical factors should encourage.

Jan 1, 1940

By John S. Crandall

Occurrence: small crystals in alluvial sands from the eroding Belt Series mica schists. Flowsheet: dragline, trommel screen, jigs, drier, crusher, screens. Value: ground, $2.50 per cu yd, garnet sand gross $60. per ton. Costs: production and sales $48. per ton. Uses: blasting sand in aircraft plants, monumental works, foundries. Efficiency comparison: superior to silica sand. Future: possibilities only touched upon, research continuing.

Jan 1, 1950

By Charles L. Elliot

Worldwide manpower utilization reached a new high at 10,482 professional man-months and expenditures increased to $19.9 million for mining geophysical activity during 1965. This is up from 9323 man-months and $14.5 million in 1964. Worldwide geophysical activity measured in percent distribution of the total manpower utilization and expenditures is presented in the accompanying Figs. 1 and 2. In terms of the total manpower utilization, ground surveys accounted for 61%, airborne surveys 18%, and mining geophysical research activity 21%. For expenditures, the breakdown was ground surveys, 49%; airborne surveys, 3901o; and research, 12%. Industry was responsible in general for 74% of the manpower utilization and 80% of the expenditures. Manpower costs in 1965 averaged $1900 per professional man-month.

Jan 11, 1966

By W. M. Brown

SEQUACHEE Valley includes portions of the counties of Marion, Sequachee, Bledsoe and Cumberland. It extends in a general direction parallel with the Great Valley of East Tennessee, some 75 miles northward from the Alabama state line. It is separated from the Valley of East Tennessee by a mountain arm about a dozen miles wide, known as Wallen's or Walden's Ridge. The genesis of the valley, geologically speaking, is simple. It is an erosion-valley along the axis of an anticlinal. The point of the wedge remains in a row of low "saw-tooth" hills, running up the center of the valley. These hills are of Lower Silurian age, and consist of Trenton limestone, covered and protected in some measure by chert. Walls of Carboniferous age form the inclosing mountains on either side; whilst a magnificent arch of Hudson River, Niagara, Hamilton and Subcarboniferous strata closes the valley at the

Jan 1, 1886