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By Marcus A. Grossmann

The Institute has established this lectureship to honor the memory of a great American metallurgist, one whose fame has continued long after his passing. As one scientist recently stated it, "All metallurgical texts gradually become outdated and outmoded, except those of the great Henry Marion Howe." It seems fitting, then, that, once every year, we shouId review, in his honor, some aspects of the science in which he was such a distinguished leader, and also discuss any new data that may help to clarify our concepts. It is my privilege, for which indeed I express the deepest appreciation to this Institute, to offer for consideration a few thoughts on the toughness and fracture of hardened steels. Before proceeding to the data, I wish to express my great indebtedness to many associates whose stimulating discussions, generous contributions of data and cooperation in experiments are gratefully acknowledged. (But I wish to absolve them of any blame that may arise from the way in which their discussions and data have been used!) First, Dr. Edgar C. Bain, Vice President, Carnegie-Illinois Steel Corporation, whose amiable but merciless criticisms and always constructive and thoughtful suggestions help unfailingly to guard against pitfalls. Then to associates at Gary Steel Works, especially Mr. H. B. Wishart, Mr. W. K. Smith and Mr. V. Elliott, for great assistance in securing data. Also to Col. C. H. Greenall, Director of Laboratories, Frankford Arsenal, and his metallurgical staff, including Messrs. J. K. Desmond, H. Markus, D. F. Armiento, H. Rosenthal and Henry George, for numerous data and illustrations. Further to Dr. J. R. Low and Dr. M. Asimow, for helpful discussions of effects of states of stress during deformation and rupture, to Mr. J. M. Hodge for discussions and data, to the staff of the U. S. Steel Corporation Research Laboratory for advice and data, and to the Metallurgical Staff at Duquesne Steel Works. The individual acknowledgments will also be found under illustrations. Acknowledgment is also due to Mr. S. C. Snyder for incredibly meticulous scrutiny of manuscript. To all of these, grateful thanks. Introduction The discussion to be offered here will deal with quench-hardened steels only, and may perhaps be considered under three headings: 1. It was found that, when ferrite was precipitated in the (prior austenite) grain boundaries of hardened steel, the notch-bar toughness was much less than in pieces fully hardened. The fracture took place in the ferrite, and the loss in toughness is attributed to the lower cohesive (cleavage) strength of the ferrite, as cornpared with martensite. 2. When notch-bar impact test pieces of quenched and tempered steels were examined as to their mode of fracture, it

Jan 1, 1947

By Marcus A. Grossmann

The Institute has established this lectureship to honor the memory of a great American metallurgist, one whose fame has continued long after his passing. As one scientist recently stated it, "All metallurgical texts gradually become outdated and outmoded, except those of the great Henry Marion Howe." It seems fitting, then, that, once every year, we shouId review, in his honor, some aspects of the science in which he was such a distinguished leader, and also discuss any new data that may help to clarify our concepts. It is my privilege, for which indeed I express the deepest appreciation to this Institute, to offer for consideration a few thoughts on the toughness and fracture of hardened steels. Before proceeding to the data, I wish to express my great indebtedness to many associates whose stimulating discussions, generous contributions of data and cooperation in experiments are gratefully acknowledged. (But I wish to absolve them of any blame that may arise from the way in which their discussions and data have been used!) First, Dr. Edgar C. Bain, Vice President, Carnegie-Illinois Steel Corporation, whose amiable but merciless criticisms and always constructive and thoughtful suggestions help unfailingly to guard against pitfalls. Then to associates at Gary Steel Works, especially Mr. H. B. Wishart, Mr. W. K. Smith and Mr. V. Elliott, for great assistance in securing data. Also to Col. C. H. Greenall, Director of Laboratories, Frankford Arsenal, and his metallurgical staff, including Messrs. J. K. Desmond, H. Markus, D. F. Armiento, H. Rosenthal and Henry George, for numerous data and illustrations. Further to Dr. J. R. Low and Dr. M. Asimow, for helpful discussions of effects of states of stress during deformation and rupture, to Mr. J. M. Hodge for discussions and data, to the staff of the U. S. Steel Corporation Research Laboratory for advice and data, and to the Metallurgical Staff at Duquesne Steel Works. The individual acknowledgments will also be found under illustrations. Acknowledgment is also due to Mr. S. C. Snyder for incredibly meticulous scrutiny of manuscript. To all of these, grateful thanks. Introduction The discussion to be offered here will deal with quench-hardened steels only, and may perhaps be considered under three headings: 1. It was found that, when ferrite was precipitated in the (prior austenite) grain boundaries of hardened steel, the notch-bar toughness was much less than in pieces fully hardened. The fracture took place in the ferrite, and the loss in toughness is attributed to the lower cohesive (cleavage) strength of the ferrite, as cornpared with martensite. 2. When notch-bar impact test pieces of quenched and tempered steels were examined as to their mode of fracture, it

Jan 1, 1947

By AIME AIME

IN many countries the lack of liquid petroleum supplies has centered interest upon the hydrogenation of coal and coal tars for the preparation of motor fuel. In the United States, hydrogenation has been of greater interest for grading up low-value petroleum fractions to the more valuable volatile fuels and for the preparation of a variety of premium products, including aviation gasolines, solvents, Diesel fuels, and lubricating oils. Chemically, the basic reason for this process is that, as shown in Table 1, the ratio of hydrogen to carbon (H/C ratio) in available raw materials is quite different from that characterizing the products sought.

Jan 1, 1936

By George Holderer

THE Enos Coal Mining Co. owns an area underlaid by coal, of approximately 5000 acres. This property is situated 9 miles from Oakland City, in the southern part of Indiana. The mine has been in operation 5 years, during which time some 350 acres have been stripped, and stripping is now proceeding at the rate of about 100 acres per year. TOPOGRAPHY These coal lands consist of gently-rolling agricultural fields which in times past were farmed for wheat. There is no timber and but very little brush to contend with. The overburden varies from 10 to 60 ft. in depth. A thin bed of slate overlies the coal, followed by limestone, which varies from 3 to 15 ft.; this, in turn, is followed by sandstone, slate, shale and clay. There is a very wide variation in the thickness of all of these beds. The coal has an average thickness of 5 ft., and is a good grade of high-volatile bituminous. MINING OPERATIONS Briefly, the sequence of operations is: drilling holes with churn drills; blasting with L. 0. X.; stripping overburden to uncover coal and, finally taking up the coal, which is sent to a tipple for cleaning and sizing. In order to show what is being accomplished by the use of L. 0. X., results will be shown from May to November, 1926, inclusive, and compared to the same period in 1925. No work was done in No. 1 pit during May, 1925, hence all figures are unduly low for this month. Drilling There are in use 8 No. 44 Loomis clipper drills, caterpillar traction with gasoline engines; recently these were equipped with extra heavy stems, measuring 26 ft. overall and 4 ½ in. dia., to increase the speed of drilling. In addition, 4 No. 1 ½ G non-traction drills have been acquired, and are used to save the time of the larger drills when recleaning is necessary.

Jan 1, 1927

By Robert L. Dean

THE pioneer mining company in Idaho to use airplanes extensively is the Yellow Pine project at Stibnite now owned by the Bradley interests. From 1901 to 1903 the gold boom at Thunder Mountain, in central Idaho overflowed to adjacent areas, prospectors discovering cinnabar and stibnite near the present site of Stibnite in Valley County. The workings were practically abandoned by 1911 through lack of capital and high costs of transportation on pack train roads over several mountain passes open only five months each year. During the World War there was some prospecting and production, and in 1921 twelve of the original companies were merged. Small-scale mining up to 1927 proved that an expenditure of several million dollars would be necessary to operate profitably. These properties were purchased by the Bradley interests during the period of 1927 to 1930. In 1927, there was no mining equipment except hand tools, no telephones, and only one building. Two mountain

Jan 1, 1935

By H. M. Woodroffe, H. K. Conn, S. J. Rice

World production of asbestos is estimated to be at a current level of almost 3.5 million tons, having more than doubled in the past ten years. A substantial part of the increase has been due to a rapid expansion in the Soviet Union. Production from that country during 1964 is estimated at 1.5 million tons and, as a consequence, Russia has displaced Canada as the leading world producer. Although traditionally the asbestos mining industry has been centered near Sverdlovsk in the Urals, two new producing areas have been under development for some time. It is expected that a new mine will be in operation in 1965 near Kiembi, Kazakhstan, some 300 miles south of Sverdlovsk, and an- other mine at Aktrovak in Tannu-Tuva, west of Lake Baikal. These developments will provide a significant increase in the production capability of Russia. Although internal consumption is expected to increase with the addition of new asbestos- cement producing facilities now under construction in Russia, there is some speculation that exports will also increase.

Jan 2, 1965

By William B Price, Ralph W. Bailey

Arsenic, antimony and phosphorus are now used in the brass industry as standard inhibitors in preventing dezincification in condenser tubes. This subject has been thoroughly covered by Barry,l who de- scribed the testing procedure by total immersion of suitable specimens in a I per cent cupric chloride solution at definite temperatures. Effects of dezincification were then determined by loss in tensile strength and elongation of the test specimens after definite periods of immersion. In the crystallography of the chemical elements as tabulated by William Hume-Rothery,2 phosphorus (metallic), arsenic, antimony and bismuth are placed in group V-B and the type of crystal lattice for arsenic, antimony and bismuth is given as rhombohedral. The Metals Handbook3 lists them as 'rhobomhedral hexagonal," with the additional notation that for arsenic this is the ordinary form at 20°C.; other modifications known or probable at other temperatures. In view of these statements and of the fact that phosphorus, arsenic and antimony are effective in increasing the resistance to dezincification, it was natural to assume that bismuth would act in the same manner. A series of tests was therefore carried out employing the methods described by Barry. Much to our surprise, bismuth did not inhibit dezincification, but rather seemed to accelerate it. Tensile-test speci-

Jan 1, 1942

By Ralph W. Bailey, William B. Price

Arsenic, antimony and phosphorus are now used in the brass industry as standard inhibitors in preventing dezincification in condenser tubes. This subject has been thoroughly covered by Barry,l who de- scribed the testing procedure by total immersion of suitable specimens in a I per cent cupric chloride solution at definite temperatures. Effects of dezincification were then determined by loss in tensile strength and elongation of the test specimens after definite periods of immersion. In the crystallography of the chemical elements as tabulated by William Hume-Rothery,2 phosphorus (metallic), arsenic, antimony and bismuth are placed in group V-B and the type of crystal lattice for arsenic, antimony and bismuth is given as rhombohedral. The Metals Handbook3 lists them as 'rhobomhedral hexagonal," with the additional notation that for arsenic this is the ordinary form at 20°C.; other modifications known or probable at other temperatures. In view of these statements and of the fact that phosphorus, arsenic and antimony are effective in increasing the resistance to dezincification, it was natural to assume that bismuth would act in the same manner. A series of tests was therefore carried out employing the methods described by Barry. Much to our surprise, bismuth did not inhibit dezincification, but rather seemed to accelerate it. Tensile-test speci-

Jan 1, 1942

CONTENTS PAGE FOGLER, M. F., and QUINN, E. J.-Scratch and Brinell Hardness of Severely Cold-rolled Metals. Discussed by H. S. Rawdon, Carl Benedicks, M. F. Fogler, A. L.Davis 1 GREEN, C. H. Eutectic Patterns in Metallic Alloys. Discussed by Carl Benedicks, Carle R. Hayward, G. E. Dalbey, George F. Comstock, C. H. Green. 3 ARCHER, ROBERT S., and JEFFRIES, ZAY.-New Developments in High-strength Aluminum Alloys. - Discussed by F. B. Coyle, M. F. Fogler, Zay. Jeffries, D. J. McAdam, Jr., Horace C. Knerr, Ernest Schweizer 6 FLICK, FULTON B.-Etching Aluminum and Its Alloys for Macroscopic and Microscopic Examination. Discussed by Samuel Daniels 22. MERICA, PAUL D., and WALTENBERG, R. G.-The Malleability of Nickel. Discussed by H. W. Gillett, Ancel St. John. L. W. McKeehan, A. L. Feild, A. L. Davis 23 ANDERSON, ROBERT J., and NORTON, JOHN T.-X-ray Evidence Versus the Amorphous-metal Hypothesis. Discussed by Zay Jeffries, Chu Phay Yap, Francis B. Foley, H. H. Lester, Edgar C. Bain, Ancel St. John, L. W. McKeehan, Carle R. Hayward, R. P: Heuer, Jerome Alexander, Carl Benedicks 26 COOK, MAURICE, and EVANS, ULICK R.-Recrystallization and Grain Growth in Soft Metals. Discussed by M. F. Fogler 36 POLUSHKIN, E. P.-Determination of Structural Composition of Alloys by a . Metallographic Planimeter. Discussed by H. S. Rawdon 36 BASSETT, WILLIAM H., and DAVIS, C. H.-Corrosion of Copper Alloys in Sea Water. Discussed by W. B. Price, W.. R. Webster, George A. Orrok, A. E. White, William H. Bassett, D. K. Crampton 38, Scratch and Brinell Hardness of Severely Cold-rolled Metals Discussion of the paper of M. F. FOGLER and E. J. QUINN, presented at the New York Meeting, February, 1925, and issued as Paper No. 1395-E with MINING AND METALLURGY, January, 1925. H. S. RAWDON, * Washington, D. C.-We had the privilege of looking over the data just given before they were published and we were not able to suggest any convincing reason for the differences that were secured

Jan 6, 1925

By H. E. Mussey

WHEN the American Institute of Mining Engineers visited the Birmingham district in May, 1888, the four Ensley furnaces (Fig. 1) then FIG. 1.-BLAST-FURNACE DEVELOPMENT IN ALABAMA. completed were referred to as monumental.1 Their dimensions are given in Table 1. Mr. Gordon stated, with considerable satisfaction, that on the preceding day one furnace had produced 165 tons. The blast was

Jan 10, 1924

By Clement K. Chase, F. Milton Lewis, Roshan B. Bhappu

In this paper an attempt has been made to review the cost trends in producing copper by conventional milling, smelting and hydrometallurgical means during the last five years. The primary objectives of this cost analysis are to provide a base for future projections as well as to indicate which cost items are more volatile in their influence on overall cost of producing copper.

Jan 1, 1979

By Luis Salazar

Internal improvements are the great seals; stamping upon the history of nations their epochs of peace, in which notable enterprises are conceived, and fresh impulses given along the path of progress. Such forerunners of national benefits have never been so notable in Mexico as in the last four decades of the nineteenth century, during which the national faith in the consolidation of peace has been a guaranty of the development of all the elements of national prosperity. Among all the improvements which have been realized with the unanimous approbation of the people, the railroads occupy a preferred place, for upon them depends the expansion of commerce, of agriculture and of mining, the three great factors of the wealth of Mexico. In a country so extensive as the Mexican Republic, where the inhabitants are greatly scattered, and great distances separate the producer from the consumer, the only way to encourage home industry, and the development of commerce, agriculture and mining, is to construct railroads, which shorten distance, facilitate transportation and minimize its costs. The mountainous character of the country makes the navigation of its rivers practically impossible, except very near to

Jan 1, 1902

By C. S. Harloff, Frank R. Corwin

THE Nichols Copper Co., associated with the Phelps Dodge Corp. and the Calumet & Arizona Mining Co., has constructed at El Paso, Tex., and is now operating a copper refinery with a yearly capacity of 100,000 tons of anodes. Transportation facilities were perhaps the most important of the considerations that led to the selection of this site. The rapid industrial development of the Middle and Far West has increased the consumption of copper there. The advantage of local refining as against shipping the copper to the Atlantic sea- board is apparent. Copper refined in the Southwest is equally competitive for export shipment, either from the Gulf or the Pacific Coast ports. The tonnage of copper produced in the Southwest not only justifies the construction of this plant, but may warrant considerable expansion in years to come.

Jan 1, 1930

By M. H. Merriss

In the last few years, there have been developed at the plant of the Nichols Copper Co., Laurel Hill, 'Borough of Queens, New York City, improvements in electrolytic copper refining by the series system that have materially increased the flexibility and economy of that system. The purpose of this paper is to discuss, as of interest to refiners and to those who have copper to refine, as well as to the engineering profession in general, the changes' that have taken place resulting in wider application and increased efficiency of the series system. Copper is electrolytically refined in two ways, which are spoken of as the "multiple system" and the "series system." In both systems, the electrolytic tanks are in series electrically. In the multiple system the electrodes in a single tank are in multiple or in parallel, thus: There are two important adaptations of the series process, one represented by the series electrolytic tank room at the Baltimore Copper, Smelting & Rolling Co., Baltimore, Md., and the other by that of the Nichols Copper Co.'s plant. At Baltimore, the anode is rolled to perfect

Jan 1, 1926

By Arthur W. Sheafer

MR. ECKLEY B. COXE, in his able and interesting paper on " The Preparation of Small Sizes of Anthracite,"* read and discussed at the Glen Summit Meeting, October, 1891, refers to the reputed immense amount of coal contained in the culm-banks, which are the unsightly accompaniment of every mining operation in the anthracite coal-regions. Mr. Coxe thinks the available amount and value greatly exaggerated, giving among his reasons (1) the spoiling of the culm by mixing with other refuse; (2) its deterioration; (3) its destruction by fire ; and (4) frequent failures to realize expectations as to the size of the banks. These points are undoubtedly important factors in determining the advisability of working any individual bank, but they have a varying influence in the several regions, some prevailing more in one than in another. Although the amount of fuel lying waste in these banks is still an uncertain and undetermined quantity, yet no one can visit the Schuylkill region without being impressed with the fact that a considerable amount of culm, too valuable to be left merely to the mercy of the elements, surrounds and encumbers each site of an old or present colliery operation. The rapid increase in the number of washeries, and the demand for leases on old culm-banks, shows that, in the Schuylkill region at least, the question of deterioration doès not play an important part. The proportion of coal to refuse, the relative percentage of the sev-

Jan 1, 1895

By William E. Ford, Edward Salisbury Dana

The NATIVE ELEMENTS are divided into the two distinct sections of the Metals and the Non-metals, and these are connected by the transition class of the Semi-metals. The distinction between them as regards physical characters and chemical relations has already been given (Art. 453). The only non-metals present among minerals are carbon, sulphur, and selenium; the last, in one of its allotropic forms, is closely related to the semi-metal tellurium. The native semi-metals form a distinct group by themselves, since all crystallize in the rhombohedra1 class of the hexagonal system with a fundamental angle differing only a few degrees from 90°, as shown in the following list :

Jan 1, 1922

By R. M. Sellwood

The No. 4 I.S.F. Smelter Complex at the Avonmouth Works of Imperial Smelting Corporation (N.S.C.) Limited commenced operation at the beginning of 1968. The furnace rating is 120,000 tons zinc and 40,000 tons lead per annum. Zinc and lead concentrates are unloaded onto a 1,000 tons per hour capacity conveyor belt and automatically weighed and sampled before receipt into a 48,000 ton capacity raw material store. Distribution is by a reversible boom stacker into 16 x 3,000 ton bays and recovery is by a front end loader. Materials are fed to 16 proportioning bins for feeding via continuous weigh feeders to a 132 square metre effective updraught area sinter machine with a material flow rate of 240 tons per hour over the machine. The required quantity of output lump sinter at up to 800ºC is fed to 2 x 600 ton storage bins on the I.S.F. plant. By-product SO2 rich gas is fed to a conventional wet gas single stream acid plant rated at 600 tons per day utilizing a dry N.T.P. gas volume of 100,000 cubic metres per hour. The hot sinter and preheated coke (800ºC) are automatically neighed and charged to a 27.3m2 shaft area I.S.F. fitted with 2 x 5.5 m. wide lead splash condensers. Grade 4 zinc is tapped and transferred to the zinc refinery. Conventional type lead bullion and slag are tapped from the bottom of the furnace through a separation forehearth. The refinery consists of 6 lead and 3 cadmium columns to produce some 52,000 tons per annum of S.H.G. metal. S.H.G. metal and Grade 4 metal is cast into various shapes as required.

Jan 1, 1970

By Victor G. Hills

CONTRARY to what seems to be the general impression, the island of Cyprus was not named for the metal copper, but the reverse was the case. The origin of the name is entirely lost. The ancient city Kition, the birthplace of Zeno, is supposed to be the same as Kittim mentioned in Gen. x, 4; Jeremiah ii, 10 and Ezekiel xxvii, 6, and Josephus states that this name seems to have been applied to the city and also to the island itself. Cyprus is 50 miles off the coast of Asia Minor. The mountains on the mainland are plainly visible across the sea from where I write six miles from the shore of Morphou bay. It is 200 miles from Joppa the port of Jerusalem, and 250 from Port Said. The shape of the island is like a lizard, the tail pointing directly toward the old city of Antioch near the northeastern corner of the Mediterranean. The island was once heavily timbered. Among the great trees the cedars were said to even excel the famous cedars of Lebanon. The Odyssey refers to it as the "sweet smelling island" and makes other references. But the continual wars of every race and age completely stripped it of its timber, and for centuries it has been woefully barren. There are two ranges of mountains. One borders the north coast and runs out in a slim rocky ridge forming the "tail." The other occupies the southwestern part of the island, the highest point being Mt. Troodes 6600 ft. high, sometimes called Mt. Olympus. Whether or not it be the Mt. Olympus, anyway right around there the ancient gods and godesses frequently "started things." These peaks are in plain sight 10 miles south from where I live.

Jan 1, 1926

By Jim F. Lemons

INTRODUCTION A nickel doesn't buy much anymore. That's even true in the cost of recovering nickel -- the commodity. A 5[C] per pound (11 [c] per kilogram) increase in the nickel price won't cover a 10-percent increase in fuel costs for processing laterite ores, nor will it cover a 10- percent increase in wages for recovering nickel from a sulphide ore. It won't even cover a 5- percent increase in the capital cost necessary to mine and process ocean nodules. The basis for this statement and a quantitative analysis of the variations in costs to recover nickel from different types of nickel ores will be discussed in this paper. During the early part of the 1970's, the interest in nickel and its potential development was shifting from Canada to the Pacific Basin area. Canadian growth rate was slowing and each additional increase in nickel capacity was very expensive (Argall, G.O., 1970). Laterite ores were attractive to developers since they were easy to mine at a low labor cost, and technologies were being developed that would allow the recovery of nickel in marketable forms (Mohide, T.P., Warden, C.L., Mason, J.D., 1977). During the last decade, new laterite production was achieved in the Philippines and Botswana, and a significant increase in production from Indonesia and New Caledonia occurred. However, recent reports on nickel identify numerous problems plaguing the industry, i.e., high energy costs that are forcing shutdowns (INCO, 1980), (Mohide, T.P., Warden, C.L., Mason, J.D., 1977), high Canadian sulphide mining labor costs (Anon., 1976), and rapid inflation of nickel capital costs (Anon., 1981b). No definitive study has been made to determine how sensitive the total cost of production is to rising energy, labor, or capital costs, or to identify to what extent increased byproduct revenues could be used to offset these production costs. The purpose of this paper is to quantify the effects of increases in energy, labor, capital costs, and by-product credits on the future cost of production from nickel reserves and/or resources. METHODOLOGY OF ANALYSIS In order to evaluate the sensitivity of nickel production costs to changes in energy, labor, and capital costs, and in byproduct revenues, an analysis was made of existing and proposed nickel operations, their costs, and their sensitivity to change. The data for these analyses were obtained from numerous sources including international govern¬ment and university publications, professional journals, company reports, private communications, U.S. Bureau of Mines contracts, and estimates by Bureau of Mines personnel. These data were collected, in part, as an ongoing effort of the U.S. Bureau of Mines Minerals Availability System (MAS) to systematically measure and classify identified mineral resources according to their respective extraction technologies, economics, and commercial availability. The MAS Program is currently evaluating the present and potential availability of nickel to the United States in relation to mining, beneficiation, smelting, refining, leaching, transportation, infrastructure, environment, land use, labor, productivity, technology efficiencies, operating capacities, deposit life, and political factors. As a summary of this data, the following briefly describes nickel ore types as each relates to energy, labor, capital, and byproducts. Sulphide Operations Nickel is currently available from sulphide deposits. Roughly 55 percent of the current world nickel production in market economy countries is from sulphide ores, although only about 20 percent of the known land-based nickel reserves and/or resources are sulphides (INCO, 1981). In 1979, the Western World sulphide reserves were estimated at about 9.2 million metric tons of nickel (Little, A.D., 1979). Sulphide ores are typically mined underground, thus resulting in high mining costs; however, these ores can often be upgraded by flotation prior to final nickel recovery and require about one-third of the energy required to recover nickel from laterites (Anon., 1981c). In addition, nickel in sulphide ores may be associated with economically recoverable byproducts, which include copper, cobalt, gold, silver, and other precious metals. Laterite Operations Forty-five percent of current nickel production is from laterite deposits. Laterite deposits account for 80 percent of the known land-based nickel reserves and/or resources (INCO, 1981). In 1979, the Western World laterite reserves were estimated at over 35 million metric tons of nickel (Little, A.D., 1979). Nickeliferrous laterites are residual soils formed by weathering, typically under tropical or near tropical conditions. They can be easily mined by open-cut methods, but generally cannot be beneficiated; thus, recovery of nickel must entail processing of the total mined ore. Usually, these ores have high moisture content (20 to 30 percent by weight) that result in additional fuel costs to dry the ore. Nickel silicates, garnierites, are, processed by pyrometallurgical methods; limonite nickel oxides are normally leached. Byproduct cobalt is not recovered from most ferronickel operations, and is only recovered to a limited extent from many leach operations.

Jan 1, 1982

By H. H. Waller, C. H. Brehaut

At the Jeffrey mine of Canadian Johns-Manville Co. in Asbestos, Que., automatic batched concrete from surface is placed underground pneumatically for distances of 2500 ft directly into forms or to a second placer for greater distances, through 6-in. pipe of high carbon steel. The use of Celite C-4-C in addition to the usual aggregates achieves greater compressive strengths, lowers cost, reduces segregation, and improves workability and placeability results. Each year 25,000 cu yd of concrete are placed without interrupting production and development work in the mine, making possible a cheaper concrete that can be poured wherever and whenever it is needed. In about 90 pct of the underground openings in the Jeffrey mine concrete is necessary to preserve them in their original sizes and shapes for production. In the remaining 5 pct, the greater portion is united with or without steel support. When large quantities of concrete were forecast for underground use at the Jeffrey mine, preliminary and first hand information regarding pneumatic placing was acquired from articles by Bernhardt and Swanson and visits to their respective mines.

Apr 1, 1956