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By A. C. Backeberg

There is no South African code for the design of reinforced concrete headframes, and all those erected have been designed on a uniform basis which, up to the present, has tended to be conservative. With certain exceptions designs have generally conformed with British Standard Code of Practice C.P. 114. In the design of reinforced concrete headframes the following loads are taken into account:

Jan 11, 1961

By R. J. Wahrer

In 1996, the Office of Surface Mining (OSM) and the U.S. Fish and Wildlife Service (FWS) completed an Endangered Species Act (ESA) programmatic Section 7 consultation. From the resultant Biological Opinion, it was found that coal mining operations conducted under federally approved state regulatory programs would not likely jeopardize the continuation of federally listed species nor result in the destruction or adverse modification of critical habitats. The requirements of the ESA and their integration into the SMCRA permitting process and the responsibilities of the regulatory agency, the FWS and the coal operator will be discussed. Guidance on the development of protection and enhancement plans will be provided and site-specific examples given.

Jan 1, 2003

By Kaby K. Kabongo

The paper is drawn from a project intended to explore a technique of prediction, control and optimization of fracture in coal induced by blasting. It evaluates the fines generated in coal submitted to dynamic loading stresses in an impact stamp mortar. The aim is to analyze a complex phenomenon of coal response to blast-generated stresses from a series of discrete simulations of shock and gas actions in controllable processes.

Jan 1, 1995

By H Jha, M C. Thomas, P Gupta, S K. Sit

The modern jig with a state-of-the-art control system is much more effective than its older version. This improved control system is used to modulate the amplitude and the frequency of the jig cycle. These two prime parameters are optimised with respect to feed characteristics for best jigging performance. Based on this understanding any jigging plant can be optimised. In addition to these established facts present study shows process efficiency improves further through optimisation of the feed quality.

Jan 1, 2007

By F. W. Jones

The perturbation of alternating electromagnetic fields by three-dimensional structures is considered. The general model is that of a semi-infinite conducting half -space which consists of regions of different conductivities. A numerical method is used to obtain the solution for the equations and boundary conditions. The effects on the fields at the surface of the half-space due to the conductivity discontinuities are shown by three-dimensional amplitude and phase plots.

Jan 1, 1973

The Crow Indian Reservation is located in the southeastern part of Montana, stretching from near Billings, in the center of the state, to the Wyoming border in the south. The Office of Surface Mining's Casper, Wyoming, Field Office is responsible for regulating mining and reclamation on Crow tribal land. Federal legislation enacted July 11, 1987, authorized the Indian tribes to implement approved Abandoned Mine Land Reclamation Programs. In early 1988 the Crow elected to develop an Abandoned Mine Land Program under the Title IV provisions of SMCRA. The tribe's plan received final approval on January 4, 1989.

Jan 1, 1992

DAVID THOMAS 1871 R. W. RAYMOND 1872-1874 A. L. HOLLEY 1875 ABRAM S. HEWITT 1876 T. STERRY HUNT 1877 ECKLEY B. COXE 1878-1879 WILLIAM P. SHINN 1880 WILLIAM METCALF 1881 RICHARD P. ROTHWELL 1852 ROBERT W. HUNT 1883 JAMES C. BAYLES 1884-1855 ROBERT H. RICHARDS 1886 THOMAS EGLESTON 1887 WILLIAM B. POTTER 1888 RICHARD PEARCE 1889 ABRAM S. HEWITT 1890 JOHN BIRKINBINE 1891-1892 H. D4. HOWE 1893 JOHN FRITZ 1894 J. D. WEEKS 1895 E. O. SPILSBURY 1896 THOMAS M. DROWN 1897 CHARLES KIRCHHOFF 1898

Jan 1, 1941

ENGINEERS AVAILABLE (Under this Beading will lie published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member,, technical graduate, aged 38, 14 years' experience in engineering, exploration, and management of copper, pyrite, and large iron mines, safety work, professor of mining in large university. Married. Open for position after June 10. No. 205. Member, graduate engineer, aged 44, with over 20 years' experience in connection with large coal and coke operations in different parts of the country, desires position as general superintendent of large coal company, or will take an interest with the management in a smaller company. No. 206.

Jan 5, 1915

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during the period Aug. 10 to Sept. 10, 1914: William Huff Wagner, Milford, Del.. Stanley C.- Herold, San Jose, Cal. Charles W. Hamilton, Tampico, Mexico R. J. Grant, Denver, Colo. A. M. Van Rensselaer, New London, Conn. John Lloyd, Wilkes-Barre, Pa. . Henry C. Carr, New York, N. Y. D. M. Riordan has been appointed to act as special adviser to the Secretary of the Treasury and has sailed on the U. S. S. "Tennessee" for Europe, where he will assist in aiding Americans in returning to the United States.

Jan 10, 1914

By D. Malhotra

This paper discusses the need for periodic auditing of mineral processing flowsheets and the potential benefits a company can gain from a study of this nature. A carefully designed flowsheet audit can have a significant impact on the metallurgical performance in the plant. Several case studies illustrating the potential benefits that can be attained from flowsheet auditing of mineral processing plants are discussed.

Jan 1, 1988

By Sandy Worden

Coal mining companies in Australia are managing the high-consequence risks across their operations more effectively by using an interactive online risk management system known as Riskgate Developed by the Minerals Industry Safety and Health Centre (MISHC) at the University of Queensland, Australia, Riskgate contains detailed information about 11 high-consequence risk areas (called topics in the system) for opencut and underground coal mines (Table 1). The existing topics are: fires; strata control for underground mining; ground control for opencut mining; tires; isolation; collisions; explosions and explosives; manual tasks; and trips, slips and falls. Every Riskgate topic is focused on coal industry activities (mining, processing, transport and storage). The scope includes mine sites, lease areas and mine infrastructure (mobile, fixed plant, field equipment, buildings, road and rail transport), and all aspects of the mine life cycle from design through to decommissioning. The topics uniformly recognize that a loss of control can result in injury or fatality, equipment damage, production loss, reputation loss and environmental damage. However, the priority focus for Riskgate is the safety of mine personnel.

Jul 1, 2013

By I Canbulat, J Emery, L Yao and C Zhang

This paper documents a process of data analytics and machine learning applied to coalmine roof convergence data. It follows a publication documenting the formation of the database. For each set of analyses Python scripts were utilised to extract data from an SQL database, with subsequent analyses also executed in Python, utilising open-source tools such as scikit-learn. Preliminary analyses with classic machine learning algorithms included multiple logistic regression, K-nearest neighbours, decision tree, random forest, support vector machine, kernel support vector machine, artificial neural network (ANN), naïve Bayes and multiple linear regression. Results indicated that relationships were complex and non-linear, with the artificial neural network most suitable. An ANN model was then refined through a standard process of hyperparameter optimisation and data augmentation to arrive at a final model. Due to the black box nature of the ANN further insight into how the parameters interacted was sought and found with Shapley additive explanations (SHAP values). SHAP values utilise Game Theory, where each input parameter or feature is a ‘player’ while the data set is the ‘team’. The SHAP value is the impact of each player on the target value, essentially establishing the contribution of each input parameter. The results from all analyses are delivered in the paper, together with insights, applications, strengths, and limitations of the methodology.

Nov 29, 2022

The Broken Hill orebodies have 'traditionally been mined by cut and fill trethods. In the mid-1950's New Broken Hill Consolidated Limited experimented with sublevel longhole open stoping but did not pursue the method due to inefficient loading and poor fragmentation. The introduction of longhole open stoping in 1968 was a radical change and was necessary to enable the profitable extraction of lower grade orebodies and this method is now used for 55% of the production from The Zinc Corporation, Limited and New Broken Hill Consolidated Limited mines.

Jan 1, 1982

By J. A. L. Napier

An essential requirement for the planning of the global capacity of a mine is a knowledge of the functional relationship between the production level and the capital expenditure necessary to establish that level. An underlying mechanism connecting capital expenditure and mine production capacity is proposed in terms of a characteristic profile of the expenditure that both precedes and succeeds production expansion. By the assignment of a representative shape to this profile, the capital expenditure of individual mines can be modelled. The empirical values describing the characteristic profile are computed for a number of gold mines, and an attempt is made to explain variations in the model coefficients from mine to mine in terms of physical parameters such as shaft depth, shaft concentration, and average rate of depth increase during the life of the mine.

Jan 1, 1981

By K McCaffery, R P. Halomoan

Two column flotation cells have been installed as single-stage rougher cleaners at Batu Hijau. The objective was to provide additional residence time in the cleaner circuit to maintain maximum recovery during high mill throughput and high feed grade periods. Installation of the columns has allowed the relatively coarse, well-liberated rougher concentrate and the relatively fine, low-grade scavenger concentrate to be treated separately, improving metallurgical performance in the cleaner circuit. Plant results show that the columns produce a high-grade concentrate at an average stage copper recovery of approximately 80 per cent. There is also indication of increases in both overall plant copper recovery and final concentrate copper grade. In addition, the operability and stability of the cleaner circuit has greatly improved.

Jan 1, 2007

By Liang Ruilu, Guo Lihua

In light of the properties on process mineralogy of the old tailings in a certain copper mine in the People's Republic of China, a new process of combined reagent and stepwise flotation is applied in which the flotation of copper sulfides is followed by the flotation of copper oxides. Recoveries of copper and associated gold and silver have been greatly increased. The tailings obtained were subjected to the gravitational separation-magnetic separation process to recover iron minerals. Tailings from iron separation are taken as fillers and sent to the pit underground. Thus, the secondary resources are comprehensively utilized.

Jan 1, 1995

By R. L. Watts

Successful mining of taconite has required the solution of a series of difficult problems, including more efficient magnetic separation. Progress in this field is evidenced by reductions in operating and capital costs made possible by the advances in permanent magnetic materials and in new circuits for better utilization of these materials. The advent of the flux control circuit appears to be one of the more important breakthroughs in permanent magnet drum design circuitry and has contributed greatly to the economics and metallurgical requirements of the modern day taconite concentrators. High strength permanent magnetic separators are now replacing electro types in many applications requiring field strengths of 900 - 1000 gauss measured at 2 in. This is made possible by the new circuits having gauss readings at 2 in. previously attained only by electromagnets.

Jan 12, 1967

Meeting, of Jan. 22, 1915.-Dr. Albert R. Ledoux was unanimously nominated-by the Board as one of the representatives of this Institute upon the Engineering Foundation Board. The following Tellers to count the votes for officers and directors on Feb. 16, 1915, were appointed: David H. Browne; Arthur S. Dwight, and Bradley Stoughton; and the following Tellers to count the ballots, on the amendments to the Constitution: Arthur L. Walker, Max Roesler, and Burr A. Robinson. Karl Eilers was appointed a member of the Library Board of the United, Engineering Society, representing this Institute in place of C. R. Corning, ;resigned. The Pick and Hammer Club of the University of Oklahoma was established as an Affiliated Student Society. The sum of $150 was appropriated to the Columbia Local Section. The sum of $29.50 was appropriated to the Chicago Local Section.

Jan 3, 1915

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members who registered at Institute headquarters during September: William B. Phillips, Austin, Texas. Will L. Clark, Jerome, Ariz. Olof Wenstrom, Boston, Mass. Robert H. Richards, Boston, Mass. Anthony F. Lucas, Washington, D. C. Hennen Jennings, Washington, D. C. P. H. Griffin, New York, N. Y. Waldemar Lindgren, Boston, Mass. H. N. Lawrie, Portland, Ore. C. Snelling Robinson, Youngstown, 0. Clarence P. Linville, Everett, Pa. E. P. Ross, Johnson, Tenn. Members of the XII International Geological Congress who made the Institute Office their headquarters while in New York A. Bigot, Caen, France. E. Gentil, Paris, France. J. Caillebotte, Paris, France. H. Saint-Clivier, Paris, France. John Ashworth, Manchester, England. Tadasu Hiki, Kioto, Japan. T. Dahlblom, Falun, Sweden. L. Milch, Greifswald, Germany.

Jan 10, 1913

71 BROADWAY, NEW YORK, Sept. 22, 1913. CHARLES W. GOODALE, Chairman, . DARSIE C. BARD, ESQ., Secretary. Committee on Precious and Base Metals, Butte, Montana. Gentlemen The wonderful success of the meeting of the Institute held in Montana makes it necessary that some public acknowledgment should be made to those to whom this success is due. We are conscious that the securing of the great number of technical papers of lasting value and the carrying to success of most complete detailed arrangements for holding the meeting have called for several months of skilled effort on your part. The benefit of the meeting is very great and extends not only to those who were fortunate enough to be present, but to our four thousand absent members and their friends as well. To you and your associates on the Committee whose efforts have made this never-to-be-forgotten meeting possible we owe far more than can be expressed in votes of thanks. Very respectfully, CHARLES F. RAND, President.

Jan 10, 1913