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By H. Foster Bain

THERE has never been a great civilized nation which did not have a mining industry; civilization cannot flourish without metal mining. Without tools we can have none of the 'industries that are the foundation of civilization and without metal mining we cannot produce the material of which tools are made. Therefore, if we have no metal mining we have no metals, no tools, no civilization. An example to illustrate this may be drawn from a recent article in the Saturday Evening Post which described the run-down condition of modern Athens. Athens is nothing but a busted mining camp! In its palmy days the Greeks so applied the leasing system to the silver mines of Laurium that the royalties, paid the expenses of government and instead of a tax bill the inhabitants received a pay check. The Persians came over to capture these mines but the Greek navy was built to defend them. When the silver mines played out, Greek civilization declined.. Our mining must continue if our civilization is to continue.

Jan 1, 1921

By Brian R. Castle, James J. Scott

INTRODUCTION Referring to a ground support system as a 'band-aid' borders on getting cute, but the application of cable slings in U.S. mining is somewhat analogous. Where problems in the roof or rib require additional support, the versatile cable sling is the answer in a variety of conditions. To fully understand how and why cable slings are used today we must briefly review their development history. Much of the thrust over the last five to seven years in ground support fixtures has been the development of hybrid systems. Taking the best of two or more existing roof bolt fixtures and marrying them into a new fixture which exhibits the good characteristics without the bad of the parent systems. Resin point anchored mechanical bolts, continuous threaded rebar bolts, and others have all be- come important fixtures in rock mass stabilization. HYBRID GROUND SUPPORT SYSTEM The cable sling system is also a hybrid, both in its parentage and in its ground support characteristics. See figure 1. Cable slings combine the techniques of cement. grouting high-strength cables, Friction Rock Stabilizers, and truss-like suspension into a versatile and high- strength ground support system. 1/2" high-strength cable is cement grouted in place in a manner similar to pre-

Jan 1, 1983

By F. H. McDowell

The electro-magnetic separator of Mr. G. Conkling, Glens Falls, N. Y., described by Mr. Birkinbine* in a paper at the New York meeting of the Institute, in February, 1889, has been in successful operation at the Tilly Foster 'mine for a considerable period, under the disadvantages which seem to be the inevitable attendants of pioneer enterprises in new technical fields. The results of a run of several months, which the Superintendent, Mr. S. P. Tomkins, has taken pains to collate, are here presented by his courteous permission, and that of Mr. E. S. Moffat, the energetic and skilful General Manager of the Lackawanna Iron and Coal Company, to whom our profession is already indebted for examples of bold and ingenious practice in mine-engineering. It is believed that these figures will assist those who are planning similar operations to decide intelligently what they may, and, more important still, what they may not, expect to accomplish. The local difficulties in the way of this experiment at the Tilly Foster mine were many and great. Only about two-thirds of the waste-dump, resulting from the assorting of previous years, is ore; and this varies in content of iron from 20 to 28 per cent. The remainder is rock, some (from horses in the vein) showing particles of adhering mineral, some (from the foot- and hanging-walls) entirely barren. The expense of overhauling the dump and removing this rock is by no means the least of the numerous items which must be charged against the concentration. Associated with the lean ore are hornblende and other minerals, carrying iron in the non-magnetic state, which must necessarily be washed away with the tailings. The waste-dump was originally located without reference to future treatment, and now can only be handled by means of a locomotive,

Jan 1, 1891

By Donald H. McLaughlin

THE activity and enthusiasm of pioneers still prevail among workers in applied geophysics1.- Within the year, new devices have .been tried out, instruments and technique have been improved and the methods of application to commercial problems have been increased in many ingenious ways. There is still great need for more skillful interpretation of results in terms of geology, but oil the whole geophysical prospecting is making encouraging progress toward finding its proper place and function in engineering and geological practice. Spectacular successes continue to be reported, particularly .from the Gulf Coast, where the race for salt domes has not slackened, and encouraging results have been giined elsewhere in the mapping of structures in the search for oil. In the mining field, however, it can hardly be claimed that the same measure of success has been obtained, for brilliant efforts worthy of wide recognition have been overshadowed to some eatent by the unfortunate outcome of surveys undertaken unwisely without recognition of the limitations of the work. Consequently, hopes were aroused that could not be fulfilled, and it must be admitted in an impartial survey that there are a few regions, chiefly in the far north, where the standing of geophysical prospecting is somewhat doubtful and where the course of public opinion regarding it shows a certain similarity to the history of the market during the past few months. Reliable work, however, is steadily going 011 and it can confidently be expected that the methods will eventually be regarded in many regions as an essential part of the technique of securing geologic data needed for intelligent exploration.

Jan 1, 1930

By P. F. McIntyre

Electrolytic refining of lead was first carried out on a commercial scale at Trail, B. C., in 1903. The capacity at that time was small, and cell-changing operations were managed with chain block and monorail. Development up to 1922, utilizing crane installations and cell additions, attained a production of 100 tons per day. Successive additions from 1922 to 1926 further increased the rated capacity to 396 tons per day. Other improvements in metallurgical practice have gradually increased production, until for the year 1935 it was 448 tons per day. During the first five months of 1936, an average daily production of 504 tons was maintained without increasing the size of the plant. Lead Refinery Buildings.—The tank room and the lead-melting and casting equipment are housed in two buildings, which parallel each other and which for the greater part of their lengths are joined by a connecting aisle. All basements, walls, sumps and floors are of concrete. Where exposed to the electrolyte, the concrete has a protective coating of asphalt (220" melting point) over a coat of asphalt paint as a primer. Buildings erected before 1924 are of wood. More recent additions are made of structural steel with gunite siding. A brick building, adjoining the older section of the tank room, houses the slimes-treatment plant. The power house, containing motor generators, air compressors and rectifiers, is constructed of tile. Cell Construction.—The electrolytic cells are of reinforced concrete lined with asphalt. They are cast in pairs, the outside dimensions of a double cell being 113 in. long by 73 in. wide by 48 in. deep. The bottom is 6 in. thick and the sides, ends and center wall are 4 in. thick. A ledge 3 in. wide and 2½ in. deep is left along the top of the side walls to carry the insulators and bus bars. Reinforcing consists of ½-in. round iron rods. Cell inspection and repair work is done in conjunction with the cell-changing operations. The repair work necessary is usually confined to renewing chipped asphalt, unless a tank has been accidentally broken. Minor concrete repairs can be easily made in place. The broken concrete

Jan 1, 1937

By W. H. Tuttle, H. R. Ahlquist, A. J. Carlson

Variations of the EVOP technique are accepted as the foun- dation in the development of Erie Mining Company's mining, concentrating and pelletizing complex at Hoyt Lakes, Minnesota. The basic one-variable- at-a-time technique served its purpose through the laboratory pilot plant as well as the full-scale production sized pilot plant. However, recognition by Erie Mining Company management of the potential of computer application and statistical experimentation in plant operation and testing led to acquisition of an IBM 1620 computer in 1961. Adaptation of established techniques in statistically designed experimentation and analysis of results is presented in actual case form including the following: 1. Determination and use of variance, standard deviation, standard errors; application of t-test in determining true differences between daily aver ages of product assays; formulation of quality control limits; determining sample size; and application of normality tests will be discussed. 2. Use of mathematical modeling and regression analysis for establishing mill storage conditions based on bin level indicator lights. 3. Polyvariable random balance design of a balling circuit test and resultant identification of primary control variables.

Jan 1, 1969

By J. E. Forciea, O. E. Palasvirta, L. G. Hendrickson

AH pilot and commercial plants working with Mesabi Range taconite employ wet magnetic separation. Progress is being made with a dry magnetic process, but this has not yet been applied to taconite except in the laboratory and pilot plants. Flowsheets in all five plants are similar, including multiple stages of grinding, each followed by magnetic separation, which rejects a finished tailing. The flowsheet in Fig. 1 is used in the preliminary and commercial plants of the Erie and Reserve mining companies and in Unit C of Oliver's Pilotac plant. At Erie the desliming operation is omitted. In the Reserve plants two ball mills are used with each rod mill. Pilotac uses flowsheet 2 in Unit A-B and has also tested flowsheet 3. Principal differences in the three flowsheets are the number of grinding stages and the type of roughing. The terms open-circuit roughing and closed-circuit roughing are best defined by the diagrams. Special Test Data Given in Table I: For the Erie and Reserve commercial plants, Table I reflects routine conditions. Pilotac, the experimental plant, has been run with several flowsheets, including those followed at Erie and Reserve's commercial operations. Pilotac data for these last two flowsheets are similar to commercial plant results and are not repeated in Table I; statistics are given, however, for special test conditions. using other flowsheets. when the objective was to 'to extra-grade concentrate, Variations Among Taconites: Although crude ore tributary to these plants is generally classified as taconite, there are important differences in mineralogy and fineness of dissemination.

Jan 1, 1959

By David Keys

APPLIED geophysics is the youngest child of that old branch of learning, that has been known from Aristotle's time as physics-the constitution and laws of nature. The mother science, with the help of mathematics, has given birth to many children, who, on becoming of age in the scientific sense, wedded more practical applications which later became known as electrical engineering, physical chemistry and acoustical engineering. Some vigorous sons still retain the family name, among which the most recent to take its place as a division of science is geophysics, which deals with the physics of the earth. Geophysics in its broad sense has many departments-meteorology, oceanography and seismology, to mention only three. Within the past 20 years, however, a special interest has arisen in the application of physical principles to, problems in geology, mining and civil engineering, with the consequent rapid growth of what has now been called "applied geophysics." Applied geophysics in this narrower sense is the application of experi-mental and theoretical physics to determine variations: and discontinuities in underground structures that cannot be ascertained from surface inspec-tion. It seems evident, then, that the physics department is the natural place in a university where the principles and methods involved should be taught and developed, for the physicist will also have had the requisite training in mathematics that the proper understanding of many methods now used will require. A knowledge of the procedure and principles, however, is not sufficient for the successful application of geophysical, methods. One may know the dynamics of flight of golf balls and of impact and yet not play a par game of golf ! The proper selection and use of the right club to suit the circumstances of the lay of the ball and an acquaintance with the possibilities and limitations of the strokes as well as the practical execution of the play is essential to a successful game. So, also, in the application of geophysical methods, it is important for the geophysicist to use the best device under the conditions presented, to know the limitations of the conclusions deduced from his physical measurements and to make the proper interpretation of the results. A knowledge of geology will be of great aid in coming to the correct con-

Jan 1, 1938

By R. B. Fuller, E. T. Casler

MANY changes were made in the methods and equipment used in the mining of pebble phosphate rock in the generation immediately preceding the present World War and it would be extremely interesting to note the improvements that will be made during the next generation. Literally, much water has gone over the dam since the days when we used local cordwood for generating steam and drying pebble phosphate rock. belt-driven centrifugal pumps operated by steam engines. and floating dipper or centrifugal dredges; when we removed overburden by small steam shovels and transported it by dinkey locomotives and six-yard cars; when washing machinery was installed on wooden structures the washers being replaced every four to six years. Those were the days when men were plentiful, and 47 different mining companies were selling their products, based on .decidedly meager information; and. like so many mining operations, little thought was given to conservation. As the importance of phosphate rock has become more prominent in the thoughts of our economists, a more intelligent approach has been made to mining problems. Vast improvements have been made in the technique and processing of the phosphate matrix and stripping of overburden, which, in turn, have brought developments in machines and equipment and a more

Jan 1, 1944

George Edward WebbeR, a member of the Institute since 1906, died in San Francisco, May 29,1922. Born in Dixmont, Me., in 1852, he went to California in 1857 where he lived until 1883 and received a thorough training in precious metal mining in the employ of his father and J. B. Haggin. In 1883, he went to the Black Hills, South Dakota, as superintendent of the Father DeSmit mine; later the Deadwood Terra also came under his management. These mines are now part of the Homestake Mining Co. In 1889, the Rothchilds asked Hamilton Smith to recommend an engineer to take the place of the late Henning Jennings, who had resigned from the El Calloo Mining Co., of El Calloo, Venezuela, in order that he might proceed to South Africa. Mr. Webber accepted the position, remaining there until 1893 when he returned to the United States on his way to Johannesburg, South Africa, where he had been appointed manager of the Crown Reef Mining Co., Ltd. Early in 1896, he became general manager of the Rand Mines, Ltd., and served in this capacity until 1911. During the latter part of this period, Mr. Webber was active in the greater amalgamations of H. Eckstein & Co., and it was largely on his advice that H. Eckstein & Co. carried out the negotiations preceding the formation of the Crown Mines, Ltd. On his retirement from South Africa, he returned to live in Ross Valley, near San Francisco, Cal. The Rand Mines, Ltd., of which Mr. Webber was general manager, was the largest company controlled by Wernher Beit, the leading London house interested in South Africa mining, whose local agents in Johannesburg were H. Eckstein & Co. This firm is now known as the Central Mining & Investment Corpn., and after the departure of Henning Jennings, Mr. Webber was the firm's most valued and confidential advisor and was very highly thought of in mining circles in South Africa. He was a ma of most upright and straightforward high character, plain spoken and sincere; and his recognized high character was one more qualification which aided his great success.

Jan 1, 1923

George Edward WebbeR, a member of the Institute since 1906, died in San Francisco, May 29,1922. Born in Dixmont, Me., in 1852, he went to California in 1857 where he lived until 1883 and received a thorough training in precious metal mining in the employ of his father and J. B. Haggin. In 1883, he went to the Black Hills, South Dakota, as superintendent of the Father DeSmit mine; later the Deadwood Terra also came under his management. These mines are now part of the Homestake Mining Co. In 1889, the Rothchilds asked Hamilton Smith to recommend an engineer to take the place of the late Henning Jennings, who had resigned from the El Calloo Mining Co., of El Calloo, Venezuela, in order that he might proceed to South Africa. Mr. Webber accepted the position, remaining there until 1893 when he returned to the United States on his way to Johannesburg, South Africa, where he had been appointed manager of the Crown Reef Mining Co., Ltd. Early in 1896, he became general manager of the Rand Mines, Ltd., and served in this capacity until 1911. During the latter part of this period, Mr. Webber was active in the greater amalgamations of H. Eckstein & Co., and it was largely on his advice that H. Eckstein & Co. carried out the negotiations preceding the formation of the Crown Mines, Ltd. On his retirement from South Africa, he returned to live in Ross Valley, near San Francisco, Cal. The Rand Mines, Ltd., of which Mr. Webber was general manager, was the largest company controlled by Wernher Beit, the leading London house interested in South Africa mining, whose local agents in Johannesburg were H. Eckstein & Co. This firm is now known as the Central Mining & Investment Corpn., and after the departure of Henning Jennings, Mr. Webber was the firm's most valued and confidential advisor and was very highly thought of in mining circles in South Africa. He was a ma of most upright and straightforward high character, plain spoken and sincere; and his recognized high character was one more qualification which aided his great success.

Jan 1, 1923

By Roman Y. Poderny, Vladimir V. Rjevskii

In the USSR, the Moscow Institute of Radio Electronics tronics and Mining Electro-Mechanics (MIRGEM) has started what it hopes will become a nationwide movement to educate mining students in the precise specialties that industry has come to require. Courses for mining engineers, the MIRGEM faculty proposes, should dovetail as exactly as possible with specific jobs available in the mining profession. Acting upon this thesis, MIRGEM revised its own curriculum in 1962 and has since presented an over-all plan for Soviet mining education before two mining school conferences as well as the Ministry of Higher Education and a number of major Soviet industrial ministries. The plan was universally approved with some suggested revisions. SOVIET MINING EDUCATION TODAY At present, mining education in the Soviet Union covers the exploitation of solid minerals and raw materials, including coal as well as ferrous and nonferrous metals. The extraction, storage, and refining of oil and gas is treated as a separate discipline. In all, there are 33 Soviet universities and institutes that train mining engineers for careers in the industrial, research and educational fields.

Jan 9, 1966

By Michel David

One of the most important questions that arises in ore estimation can be stated as follows: What is the error when one extends the grade of a sample to a certain volume? The theory of regionalized variables, with the concept of extension variance, provides a response to that crucial question for any kind of sample extended to any volume. For the usual "extensions" encountered in current mining practice, some simple results can be derived from that theory which was initiated by Dr. G. Matheron. These results have been applied to a stratiform lead-zinc deposit for which several estimations of grade, tonnage and related precision have been made for a series of grid sizes such as might be used in a progressive exploration program.

Jan 1, 1969

By C. H. Curtis

The valuable mineral content of the current feed to the Miami concentrator is as follows: copper, 0.7 pct total; molybdenum, 0.01. Flotation of this ore yields a sulphide concentrate containing: chalcocite, 44 pct; molybdenite, 0.5; pyrite, 50.0; insol, 5.5. A combination of potassium ethyl xanthate and pentasol amyl xanthate as collectors, and pine oil as frother, are used in this flotation. Rejection of pyrite is encouraged by holding the amount of collectors used to the minimum consistent with copper recovery and by operating at high alkalinity (equivalent to 0.35-0.40 lb CaO per ton solution of pH 11.0).

Jan 4, 1950

By CHRIS A. HARTNAGEL

For the second consecutive year, the production of crude petroleum in New York has fallen below the 5,000,000-bbl. Mark that had prevailed previously since 1937. In 1945, the output totaled 4,658,000 bbl., a decrease of slightly more, than one per cent from the 1944 production. This total represents 2 per cent of the stripper-well production of the United States, which in turn is I 3 per cent of the total annual yield of the nation's petroleum.

Jan 1, 1946

By R. Dawson Hall

Discussion of the paper of R. DAWSON HALL, presented at the San Francisco meeting, September, 1915, and at the New York meeting, February, 1916, and printed in Bulletin No. 105, September, 1915, pp. 2013 to 2021. R. DAWSON HALL, New York, N. Y.-The general practice in the past has been to view the roof as being somewhat subject only to shear. In fact the action of the roof under the stress of its own weight has been but little considered, not because the matter is unimportant but because it is so complicated that it has been felt that an analysis of it would not result in any conclusions definite enough to justify the inquiry. The result has been that the consideration of the subject has fallen into the hands of persons who are not experts in the study of beam and plate stress. They have been disposed naturally to view the destruction of the roof as the outcome of the simplest of stresses-vertical shear. In the lack of a careful consideration of the conditions of roof fracture it was thought that the roof consisted of a number of horizontal layers, which were each of them weak, because, no matter how strong they might be they usually lacked sufficient depth. This view of the condition of the roof would naturally lead one to expect that it would yield to bending moment, the various layers succumbing one by one to their lack of the necessary radius of gyration to meet such severe stresses. But,

Jan 5, 1916

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 Dan A. Permenter

This paper assesses some of the critical factors that must be considered and addressed in the implementation of small computer systems for technical applications within a coal company. Aspects of hardware selection that are somewhat specific to the coal industry are discussed, and a table of potential areas of application is presented. The dilemma of internal software development is presented and a software development program based on a users group approach is outlined and discussed in detail.

Jan 1, 1983

By G. M. Schwartz, G. A. Thiel

THE first record of the quarrying of dimension stone in Minnesota dates back to 1820 when limestone was quarried locally for part of old Fort Snelling. Limestone quarries were operated at Stillwater, Mankato, and Winona as early as 1854. Granite was quarried first at St. Cloud in 1868, and within a few years thousands of tons were shipped to widespread points. Rough dimension stone for large buildings furnished the first important market, but beginning in 1886 paving blocks were in demand. The largest shipment was in 1888, when 1925 cars were shipped from the St. Cloud area. Quartzite was quarried first at New Ulm in 1859 and somewhat later at Pipestone and elsewhere in southwestern Minnesota: The productive dolomite quarries at Kasota were opened first in 1868 and have continued as large producers of a variety of stone to the present time. At present, the industry is controlled by relatively few operators, and for that reason detailed figures on dimension stone are not released for publication. A general idea may be obtained from the data in the Minerals Yearbook for 1948. The figures for total stone produced in Minnesota are 1,804,000 tons valued at $5,090,652. Probably the largest item in the latter figure is received from dimension stone. A better idea of the situation, in relation to the country as a whole may be gained by using the data for 1930 when more companies were operating in Minnesota, and complete figures were published. In that year Minnesota produced granite valued at $2,668,119 and ranked third among the states in value. Minnesota's production of granite was almost exclusively for dimension stone. In the same year Minnesota produced 300,000 tons of limestone (dolomite) valued at $840,860, and this likewise was mainly dimension stone. In finished limestone Minnesota ranked second among the states in 1930. Sandstone and minor amounts of quartzite are the only other dimension stones that have been produced in Minnesota, but the quarries are now inactive. The commercial stones of Minnesota have been described in two reports by Bowled and by Thiel and Dutton.2 The early history of quarrying in Minnesota and extensive notes on the various rocks are given by N. H. Winchell.3 Small limestone and dolomite quarries were numerous throughout the area of Paleozoic rocks in southeastern Minnesota. Early production was largely dimension stone. With the increased use of Portland cement, most of these ceased production, and today only those at Kasota and Winona remain in operation. In recent years many quarries have reopened and new ones started, but these are devoted to the production of crushed rock and agricultural lime. As the application of modern quarrying and finishing methods increased, small companies in the granite business have dropped out, and the remaining companies have modernized their plants, purchased old quarries, and opened up new ones, thus furnishing a wide variety of granites suitable for most of the customary uses. It is the purpose of this review to present notes on' the geology and operations of each of the quarries now operating within the state. Granites and Related Igneous Rocks The term granite as used in this report includes granites, gneisses, diorites, gabbros, and other igneous rocks. The granites of greatest economic importance are found in three widely separated regions, see Fig. 1. 1-Central Minnesota in the region of the city of St. Cloud, 2-the upper Minnesota River valley region, 3-the northeastern portion of the state, commonly referred to as the Arrowhead region. The St. Cloud Region: The rocks of the St. Cloud region are mainly granites and related rock types such as monzonites and quartz diorites. The stones may be grouped into three major types, namely, pink granite, red granite and gray granite. Most of the pink granite occurs in the area to the southwest of St. Cloud. The rock is best described as stone with large pink crystals set in a finer grained black and white background. The minerals of the matrix occur in remarkably uniform sizes, and the pink crystals are sufficiently uniform in. their dis-

Jan 1, 1952

By AIME AIME

ON Thursday a most interesting symposium on "Gases in Metals" was held, with both morning and afternoon sessions. The morning was devoted principally to the considerations of the steel maker, the nonferrous field being taken up in the afternoon period. Dr. John Johnston, as chairman, introduced the subject with "A Short Analysis of the Gas-metal Problem and Its Practical Importance." He then introduced P. H. Brace who explained in considerable detail the various vacuum fusion and other methods in use at present, both here and abroad, in the study of "gases" in metals. He was fol¬lowed immediately by H. W. Graham on "The Effect of Oxygen in Steel." The papers elicited considerable discussion, the point being particularly noted by both Dr. Rawdon and Dr. Sauveur that a knowledge of "total oxygen" alone is not sufficient information for the metallurgist, distribution of oxygen being probably the more important. Dr. Johnston, in commenting on the lack of agreement among many of the methods now in use, such as the Ledebur and vacuum fusion, spoke of the contemplated plan of the Iron and Steel Division to have a number of standard samples analyzed by many laboratories by the various methods, the Bureau of Standards acting as a clearing house, so that more definite information may be obtained on the comparative accuracy of the method.

Jan 1, 1933