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By K. D. Weverstad, J. E. Cleveland, J. C. Franklin, J. W. Black

A mined-out stope being backfilled with classified mill tailings was continuously monitored, both upstream and downstream, to determine the radon concentration associated with the mill tailings. The radon monitoring was done before, during, and after the backfill operation. Data taken during weekends when no mining activities were influencing the radon concentration showed a 90 percent reduction in radon discharge from the stope after being backfilled. Water used to mix with the classified sands showed an increase in the heavy metals concentration immediately after seeping from the inplace sand. However, the water used in backfilling is less than ½ of 1 percent of total mine water discharged. The change in contamination is not measurable at the pumping station.

Jan 1, 1982

Kaolin deposits in Georgia lie in a belt that stretches across the central part of the state from Alabama to South Carolina. In 1977 the state's kaolin production was an estimated 4.58 million tons (5.05 million st) or 77% of US production. While mining methods vary, stripping contractor W. F. (Billy) Jackson of Wrightsville, Ga., depends on a fleet of 18 twin-engine elevating scrapers to move the hulk of overburden and clay. Owner Billy Jackson explains that the soil in this part of the state is perfect for scraper operation; overburden ranges from Georgia red clay to a sandy gumbo material. Apart from some shale, very little rock is encountered, thus eliminating any blasting re¬quirement. Most of the material can be removed with cutting edge teeth or with drop center blades.

Jan 6, 1978

By Christopher C. Barton

Each variable known to affect laboratory measurement of fracture-energy and fracture-toughness is reviewed. Specific examples are cited where each of the variables have been isolated.

Jan 1, 1982

SAFETY in open-pit mining receives a minimum of notoriety, but its significance in profitable and efficient operation is as great as in other methods of mining. Open-pit operators from Arizona, New Mexico, and Mexico, exchanging ideas on safety at a symposium during the recent annual meeting of the Arizona Section, AIME, discovered unanimity of opinion that the successful safety program depended on managerial and supervisory support with the vigorous cooperation of the employes. Safety Organization The operation of a safety program is dependent on the ability of management to project enthusiasm through the company organization. This requires a suitable method of communication to the supervisory and employee levels so as to approach them in a manner that will inspire cooperation. Safety committees comprised of various combinations of managerial, supervisory, and employe personnel are frequently used for this purpose. The open-cut mine of the Chino Division of the Kennecott Copper Corp., Santa Rita, N. Mex., operates its program through management, a full-time safety engineer, and two safety committees, the Departmental and Shops Safety Committee and the Central Safety Committee. The Departmental and Shops Committee consists of one employe from each department and shop and the safety engineer. The selected members serve for a period of one month. This committee meets once a month, the only representative of management being the safety engineer because it is believed that employes will speak more freely when their supervisors are not present. The duties of the committee are to report hazardous conditions and make recommendations, but the committee has no authority to approve or disapprove. The Central Safety Committee is comprised of supervisory personnel from all departments and shops, and one member of each of the five bargaining organizations. Members of this committee are permanent and hold meetings soon after the departmental group to take action on recommendations of the latter. The committee system insures participation of all levels of personnel in the accident-prevention program, thereby stimulating safety consciousness. The New Cornelia branch of the Phelps-Dodge Corp., uses three groups to conduct the safety program; the General Safety Committee, Division Safety Committee, and the operating-unit safety meetings. The unit safety meetings provide for active participation of employes in discussion of various phases of the program. Within these groups vigorous opinions regarding safety are often expressed and the workmen are critical if they recognize a digression from the adopted safe-practice procedures. These monthly discussions give the program vitality. The Division Safety Committee is composed of the division superintendent and the division department heads, and follows an established pattern in discussion of all phases of the safety program. The General Safety Committee, made up of the manager, division, and department heads, makes decisions on policies and procedures; it renders decisions on recommendations and suggestions. Management at the New Cornelia branch feels this system of safety committees and meetings has been active in advancing the program. Safety Codes In the open-pit mines of the Southwest, a safety code for operation or service of equipment, methods

Jan 1, 1952

By Tuncel M. Yegulalp

This article summarizes the preliminary results of continuing research at the Henry Krumb School of Mines. Columbia University, which is directed towards improving the production efficiency of mining operations. The purpose of the particular

Jan 1, 1979

The United States has never been a large coal exporting nation, and normally such shipments, aside from those to Canada, have been relatively small. Since the first railroad was built across the Allegheny Mountains, the imports have been quite small also, although fairly large tonnages of Canadian coal have moved into the extreme northeastern and northwestern states at times. In Table 21 are shown all data available about these shipments from 1790 to 1939, inclusive.

Jan 1, 1942

By Bruce A. Kennedy

Lufthansa flight 497 roared down the runway and climbed rapidly through the early morning mist hanging over Pudahuel airport and the city of Santiago, Chile, into the brilliant sunlight above the clouds. As the plane banked onto course for Lima, Peru, we got what was possibly our last look at the beautiful snowclad mountains that ring Santiago. To the northeast was the massive hump of Aconcagua, the highest mountain in the Southern Hemisphere, wreathed in clouds and virtually looming over Rio Blanco, the new mine put into production by Cerro de Pasco just one short year before. Almost a thousand miles to the north lay the massive open pits of Chuquicamata and Exotica, and a little closer to Santiago the El Salvador mine. Behind to the southeast, clinging to the steep slopes of the Andes, was the large and awe-inspiring El Teniente mine at Braden. These mines, once the bastions of such companies as Anaconda and Kennecott, had a new owner-the Government of Chile. On the plane were a number of people who had spent a large part of their lives in Chile operating these mines and plants, and who now were suddenly faced with the necessity of starting new lives somewhere else. To them, this was their last look at the country which not too long ago was their home, a bittersweet moment of reminiscence and a time for questioning what the future held.

Jan 1, 1971

By T. F. Witherbee

IN a paper read at the Lake Superior meeting, August, 1880, an account was given of the successful use of Rendrock and Monaky powder upon a scaffoldn and salamander in the furnace. On April 5th, 1881, the same trouble called for like treatment, which, though not so immediately. successful, was on the whole more instructive than the first trial, and points, I trust, to a reasonably sure remedy for all such difficulties. Up to December 4th, 1880, foundry and mill iron were made from Old Bed and New Bed magnetite, and Kearneyy red hematite, when a return was made to Bessemer iron, from an inferior quality of New Bed ore as compared with that used during first blast. January 18th, 1881, New Bed, Chateangay, and East-shaft, a newly-opened Bessemer deposit of Messrs. Witherbee, Sherman & Co., were first used, and continued up to February 13th, on a fuel charge of 80 per cent. anthracite and 20 per cent. coke, the product on the three ores being about 10 tons more per day than on New Bed alone. From this time until March 11th all coal was used, and New Bed, Chateangay, and East-shaft ores, up to February 22d, and from that date Chateangay and New Bed, the product falling off 9 6/10 tons per day as a result of not using coke. It is fair, however, to state that the furnace was not in good condition during' this period, being over-burdened, and the New Bed ore was, temporarily, uncommonly poor, for reasons of no particular interest here.. It required to properly flux it at least 140 per cent. of limestone; and 101 per cent was actually used. March 11th, all Chateangay ore and 80

Jan 1, 1882

By J. H. Bramwell

THE following experience in rebuilding a furnace crucible while in blast may not be wholly uninteresting to some, notwithstanding its purely practical character. Few are aware of the frequent calls made on a furnace manager's skill and ingenuity, to meet the irregularities which present themselves with kaleidoscopic variations in the operations of furnaces. Unfortunately the methods pursued in overcoming these practical difficulties are too seldom recorded, and much valuable information is lost that could not fail to be of value to many, and to none more so than the educated technical manager, with a limited practical experience, who, without a literature or record of any kind to refer to, finds himself, in times of emergency, dependent and looking for assistance from those whom it is his province to instruct and direct. With positive data, however, that like difficulties have been successfully overcome, he can confidently resort to similar expedients, with such modifications as the circumstances may demand in his particular case, and pull through seeming impossibilities in the face of ignorant prejudice. The Quinnimont Furnace (60 x 15 feet) had been in operation but two months, when it became necessary to draw the tuyeres out a distance of 18 inches, in order to give them a resting-place; the brickwork under them being completely cut away, so that after each

Jan 1, 1877

By Franklin G. Pardee

IN 1920 the Minnesota Tax Commission estimated a reserve of 1,341,674,538 long tons of iron ore in Minnesota, the Michigan State Tax Commission report showed 199,092,855 long tons in reserve in that state, and the Wisconsin Geological Survey set the Wisconsin reserves at 21,500,000 long tons. The total reserve that year for the Lake Superior District amounted to 1,562,267,393 long tons. Ten years later the reserves of iron ore in these same districts were Minnesota 1,235,227,510, Michigan 168,349,823, and Wisconsin 23,000,000, or a total of 1,426,577,333 long tons. The decrease in ore reserves in this ten-year period was 135,690,060 long tons, but the shipments were 520,746,975 long tons. In other words, the ten-year depletion in reserves was only 8.68 per cent. If similar conditions carry into the future this calculation would indicate a life for the ore reserves of the Lake Superior region of over 100 years.

Jan 1, 1933

By R. W. Raymond

THE specimen of anthracite which I exhibit is from the Ortiz Mine Grant, about fifteen miles southwest of Santa Fe. The beds belong to the lignitic formation of the Galisteo, which Hayden and

Jan 1, 1874

By A. J. Griest, J. C. Danko

IN the course of vacuum evaporation experiments, sublimation figures were observed on the surface of a pure nickel specimen. A cubic figure, typical of those observed on this specimen, is illustrated

Jan 1, 1957

By William J. Millard

The Island of Trinidad has much the same geological history as the continent of South America. There are present in this area Cretaceous, Tertiary and Quaternary rocks, which were deposited in a basin covering eastern Venezuela and Trinidad, very much as rocks of the same age were deposited in the Maracaibo Basin in western Venezuela. Along the north coast there are metamorphosed and semimetamorphosed Cretaceous rocks which are found as semicrystalline limestone, schists and quartzites, etc. Both the Cretaceous and Tertiary rocks are petroliferous and are responsible for the production of oil in Trinidad and eastern Venezuela. The geological column in the oil-bearing region of Trinidad is shown below.

Jan 1, 1931

By F. G. Miller, J. M. Podgursky

Laboratory and pilot plant work on tabling of 14-mesh X 0 hydrocyclone under flow are summarized. Included are: operating principles of hydrocyclones and tables; performance of these two devices, separately as well as in combination; comparison of the combination hydrocyclone-table system with other fine-coal processing systems; and application of the hydrocyclone-table system in fine-coal circuits. The data show that the table actually compensates for the shortcomings of hydrocyclone and makes a combination table-hydrocyclone system attractive, particularly in those cases where fine pyrite is one of the major contaminants.

Jan 1, 1973

By L. E. Garner

Aggregate resources should be considered primary factors in urban development. Resource planning is essential because land values, previous construction, or zoning restrictions often preempt exploitation of aggregate deposits within an urban area. Sequential land use practices allow development of area prior to urban development population and aggregate consumption trends in Austin, TX, indicate that substantial quantities of reserves will be lost to future development. Aggregate materials are present in nearby areas. However, a comparison of transportation and reclamation costs indicates that reclaiming land after mineral extraction can be significantly cheaper than transporting materials longer distances.

Jan 1, 1982

The meeting of the Institute at St. Louis brought together many members of the Women's Auxiliary, and Mrs. Philip N. Moore, who was nominated as the Director for the St. Louis Section, took the occasion formally to inaugurate the organization in that district. A meeting was held at the Planters Hotel, anti after discussion as to, the aims and objects of the. Auxiliary, officers were nominated for the' Section; the meeting then adjourned for two days, to he resumed in Joplin.. Here a very successful meeting was held, at which the Vice-Chairman, Secretary, and Treasurer were elected. A great deal of interest was arouse under the able directorship of Mrs. Moore the St. Louis Section is likely to become a large and active organization. The president of the Women's Auxiliary, in opening the meetings, told the ladies present of the inauguration of-the-Society in February, 1917, and of the work which had been accomplished up to date. She told how the Society devotes itself to patriotic and humanitarian work along lines acceptable and interesting to the Mining Engineer, standing always alongside and behind the men of the profession. The Central Welfare Committee of the organization has three Sub-Committees: Foreign Relief, Emergency, and Americanization, and under one or other of those heads most of the work of the' Society has been done. Mr. Hoover was responsible for the inception of the Foreign Relief Committee, as its first work was the collection of funds for the supplementary meals for the Belgian Children. Under the energetic administration of Mrs. H. Knox, this sub-committee raised $12,100 in the period between the February meeting and the Declaration of war by the United States, when our government took over the entire duty of feeding starving Belgium. The organization of the Belgian Relief Committee, as it was styled, still remains, but the members are now asked to take up the question of relief in France. The President, Mrs. S. J. Jennings suggested at the St. Louis meetings that one way of working for the foreign relief alight be that all the members of the Auxiliary should, during the period of the war, forego all giving' and receiving of Christmas presents, except those they have been accustomed to give to the poor or in charity, and those they would give to the men in the services of the United States; that the money usually spent on the Christmas gifts should be put into a fund to be sent abroad for the fatherless children of France, as a gift from the families of the Institute. A good deal of discussion followed this proposal, as some of the ladies felt that children should have their Christmas gifts as usual. The Director of the Section emphasized the truth that the Christmas spirit was the .spirit of giving and sacrifice, and that no sacri-

Jan 1, 1918

By R. W. Raymond

After the publication of the Atlanta paper of Mr. Robert W. Hunt on " Specifications for Steel Rails of Heavy Sections Manufactured West of the Alleghenies,"* I received from Mr. B. F. Fackenthal, Jr., the following comments: "I note that, in giving the chemical composition of rails, Mr. Hunt does not consider the question of copper. Yet we all know very well that its presence is more or less injurious, as it tends to red-shortness. Bessemer pig-iron carrying

Jan 1, 1897

By T. V. Falkie, Robert Stefanko

Coal Mine Health and Safety Act in December 1969, the most comprehensive law in the history of the coal mining industry went into effect. Hardly anyone will quarrel with the philosophy that all miners in the United States should be afforded equal protection under the law irrespective of the state in which they reside. Furthermore, it appears contrary to any sound judgment that a competitive advantage should appear to accrue to a mine operator because his operations are located in a state with less stringent (and costly) health and safety laws Yet it is recognized that the quality of state mine laws and inspection agencies has been extremely variable. Why, then, should there be such resentments over the passage of the Act? The Act was written In the highly emotionally charged atmosphere following the Consol No. 9 disaster: the technical expertise within the industry was discredited and largely ignored; and those directly involved in the writing of the Act were non- technical and largely nonmining people. The result was that the law incorporated certain requirements that were impossible to meet (automatic brakes are the classical example) and certain parts that were too ambiguous and consequently open to interpretation.

Jan 1, 1971

By A. C. Dorenfeld

CHANGES in circuits are often made in milling operations. At the same time that these changes are being evaluated the ores are changing. Even from the same mine, the ore is usually variable as to amount and type of mineral content, degree of association of valuable and gangue minerals, amount and types of soluble salts, hardness, etc. The question then arises whether any small differences in results, after changes have been made in the various circuits, are really due to these changes or whether the variability of the ore can account for those differences. Statistical evaluation provides one method of answering the question that arises so often in beneficiation studies: Did changed results come about because of changed process, or did ore variation cause the change? In this case, data were available for statistical analysis from an operating period of 42 months, representing treatment of approximately 1 million tons of ore. During this period there had been two flowsheet changes: 1) regrind of the zinc circuit middlings was introduced, and 2) alcohol- pine oil frother mixture was substituted for cresylic acid-pine oil frother mixture. Findings are in Table I.

Jan 10, 1954

Masjid-i-Su1aiman.—There have been no new developments in the Masjid-i-Sulaiman oil fields during the year 1938. In spite of the age of this field, the fall in dome pressure shows no appreciable variation from the low rate of about 0.3 lb. per sq. in. per million tons net production. Drilling has been limited to deepening old wells and to new wells required for maintenance of production and general reservoir control. The rate of offtake has been reduced over the past few years, partly because of depletion of the oil column, and it is expected that future offtake from the Masjid-i-Sulaiman field will be stabilized for some years at around the present figure of 3,000,000 tons per annum. Haft Ke1.—An exploratory well to test deeper formations in the Haft Kel field has proved the existence of productive conditions in the Eocene, which underlies the Asmari limestone (the main producing horizon). Drilling to the northwest in the white-oil springs area has revealed the presence of a separate structure with productive potentialities. One well with a satisfactory production rate has been completed. Offtake from the Haft Kel field has steadily increased since it first came on to production in 1929. Naft-i-Shah.—Production from this field has continued to supply market requirements in northwest Iran. The policy of returning surplus products to the reservoir, which was adopted at the beginning of 1936, has been continued.

Jan 1, 1939