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By Will Mitchell

There are in this country some 20 or 30 societies for engineers and engineering scientists. Most of these organizations are autonomous, and there is little or no cooperation among them. Many do not touch the lives of our Institute members. However, during the course of the years several societies closely associated with the AIME have banded together to handle specific situations where cooperation was necessary. It is believed by many engineers that the functions of these cooperative societies should be analyzed and a plan set up to unify the engineering profession into an organization similar to the American Medical Association and the American Bar Association. The preliminary study of the AIME Committee for Inter-Engineering Society Cooperation has indicated that the following organizations bear upon the professional lives of our members. Some of these are federated groups, such as EJC and ECPD; others are individual-member participation groups, such as the Founder Societies and NSPE.

Jan 10, 1960

The role played by lawyers in business has, in the course of the last 15 to 20 years, changed perceptively. This development has coincided with, and indeed has been a reflection of, the changing nature of Australian business, especially as the mining industry established its predominance in the Australian economy. The nature and extent of governmental regulation of business, too, has changed markedly. As a consequence, there has been a qualitative'change in the nature of commercial law practice. For the needs of business to be met, lawyers have had to develop specialist skills in new areas. Furthermore, there has been the emergence of the "in-house" lawyer, who increasingly plays a primary rather than a subordinate role in corporate law practice. There is no evidence to suggest that this trend, which is by now so well established, will prove to be ephemeral. Instead, with all indications pointing towards even greater governmental regulation of business activities, the intimate role of the lawyer in business seems entrenched.

Jan 1, 1980

By G. C. Mudd, E. J. Myers

Within the last 15 years David Brown Gear Industries has manufactured approximately 200 large mill gears over 6m diam., 58 of them over 9 m and up to 12 m diam. The experience has not been without problems, due to a lack of clear understanding of the loads and stresses imposed on large gear wheels. American Gear Manufacturers Association (AGMA) practices suggest that a service factor be used for mill gears. But what is meant by "service factor"? The layman might be forgiven for believing that the term is synonymous with "safety factor," but this is certainly not true. The service factor is an aggregate of the following in some proportion: -An application factor, i.e., an allowance for the fact that systems do not run smoothly with uniform torque. -An ignorance factor covering the imperfections in the basic gear calculation. -Possibly a safety factor. In the following sections some of the ways in which the limits of applicability can be overstepped are discussed.

Jan 1, 1983

By Gemei Yang, Yihui Zhao

In caved goaf, the friction loss of fluid head is: [h = (R'+ R/Q/ )] Q (for one-dimensional transition flow). The R' and R, which are the functions of two dimensional spaces, are calculated through an empirical formula. Then, the bulking factor and permeability are determined. It is supposed that the airflow in porous media are similar to those in tiny tubes crossing each other. Therefore, the network calculation technique can be used to tackle the field transition flow problem. A lot of case studies showed that the emission of methane in mines mainly depends on the air velocity and has little relation to air pressure. Summing up our experience and experiments, we provide an empirical formula to calculate the gas emission rate per unit area. By means of mass conservation and network calculation, the methane content distribution in steady-state is worked out. Then the dynamic change in airflows and gas content can be analyzed by the characteristic-difference method.

Jan 1, 1987

By J. D. Miller, J. Hupka

Important aspects of kerosene penetration into tar sand have been investigated. The natural tar sand porosity was measured and used to analyze the performance of the hot water process. Subsequently, pretreatment experiments, using 20-kg tar sand samples (Asphalt Ridge and Whiterocks, Utah) and kerosene as a diluent were carried out at the expected summer temperature (26°C) and the expected winter temperature (-14°C). The natural tar sand porosity accessible by diluent has a crucial impact on the reduction of bitumen viscosity and influences the penetration time required for successful bitumen separation from tar sand by hot water processing. Thus, the tar sand porosity is a critical variable that determines appropriate operating conditions. Experimental results indicate that diluent penetration into the Asphalt Ridge tar sand (high porosity) is almost complete after 30 min, whereas for the Whiterocks tar sand (low porosity) the penetration process is much slower, being still incomplete after 15 hours regardless of the ambient temperature.

Jan 1, 1994

By Charles Catlett

The rapid development of the Portland-cement industry implies that the country is being very carefully searched for material suitable for its manufacture. Such material can be found at a great many places; but deposits thoroughly satisfactory in chemical composition, and at the same time meeting all the other requirements connected with the economic production and profitable marketing of the product, are exceedingly few, if I may judge from the investigations which I have had to make in a number of States. The raw mixture which by its clinkering and grinding forms Portland cement contains approximately 75 per cent. of carbonate of lime. This is found in nature as limestone or marl. The natural rock commonly carries either more than the required percentage of carbonate of lime (in which case it has to be reduced by suitable admixture of clayey ingredients) or less—in which case purer lime carbonate has to be added. The controlling ingredient, therefore, is carbonate of lime, or limestone of the right composition.

Jan 1, 1908

By Jesse Jones

1. BRINELL tests at progressively increasing temperatures are given for a representative lead-base and a representative tin-base babbitt, showing that the former has superior resistance to deformation at the working temperatures of bearings. 2. Small squares of bearing bronze, tinned and then babbitted with a representative lead-base babbitt and a representative tin-base. babbitt were subjected to compressive loading. The lead-base babbitt showed less average compression than the tin-base babbitt. Compression did not materially increase the Brinell hardness of the babbitts. 3. A process and a tool are described for giving smoother and more accurate surfaces to bearings than has heretofore been possible. The following experiments have recently been carried out in the chemical laboratory of the Westinghouse Electric and Manufacturing Co., Pittsburgh, Pa. While the work is incomplete, it is described at the present time because data on the comparative merits of lead-base and tin-base babbitts are of interest in connection with the present shortage of tin.

Jan 8, 1918

By Reinhard Fischer

The consumption of lead for batteries in some western countries and Japan amounts to 870,000 T. annually. Battery life is 2-3 years. Therefore after a short time a considerable quantity of lead flows back to smelters. The production of lead from scrap batteries is discussed from the following points of view: 1. Separation of the acid contained in the batteries. 2. Separation of the components which are free of lead from the components containing lead, e.g. cases, separators. 3. Separation of metallic lead from lead compounds. 4. Avoidance of manual-work. A process has been developed and perfected at a plant, which began operation in 1965. The procedure consists essentially of the following steps: 1. Breaking the cases and removing the acid. 2. Crushing the batteries in an impact mill. 3. Screening off separators. 4. Separation of slurry. 5. Gravity separation of metal and organic material. The plant has a one-shift capacity of -24,000 T. batteries/year.

Jan 1, 1970

By P. R. Khangaonkar, G. Bhaskar Raju

Three types of flotation columns were developed with a column dia of 8.0 cm and a length of 160 cm. The first type consists of an ordinary column fitted with a porous plate at the bottom. The second type consists of two electrodes at the bottom to obtain very fine and uniform bubbles generated electrolytically and the third is a combination of first and second types, i.e. to get both electrolytic bubbles and air from the compressor through porous plate. Three different ores were tested-gold tailings for recovery of scheelite, copper tailings (chalcopyrite) and oxide copper ore. In the case of scheelite and copper oxides, good results were obtained with the first type of column itself, whereas the third type column was found fairly effective in the recovery of chalcopyrite. The variables like the effect of reagent concentration, column height above the feed point, feed flow rate, current density, air flow rate, particle size etc. were examined.

Jan 1, 1988

By E. D. Dainty, B. E. Enga, D. L. McKinnon

Following considerable laboratory studies concerning particulate control systems for underground use, a program was commenced to develop practical real life implementation systems. This program covers the implementation in seven mines of particulate filter systems to 10 engine models from three engine manufacturers in 12 different vehicle types, a total of 24 vehicles. As the program ran, one mine had to drop out and a mutually agreed upon system could not be arrived at for another. Hence, the program included five Canadian mining companies. Several of the vehicles trialed at Brunswick Mining were trialed by Brunswick themselves. Nonetheless, the data is presented. This paper covers the work performed from the beginning to the end of the demonstration program. Data collected to properly select and design filter systems along with technical conclusions of the demonstration are presented. Also presented are the results of a survey that highlights the participating mines' acceptance of the technology.

Jan 1, 1991

By S. Ersayin, I. Iwasaki

Laboratory- and pilot-scale tests were carried out to study the effects of a magnetically enhanced hydroseparator on a magnetic taconite sample. The test parameters included feed flow rate, percent solids and magnetic field strength. Laboratory tests showed that magnetic iron losses could be effectively prevented by applying a magnetic field strength of 0.003 T (30 gauss) to a hydroseparator. A relatively uniform magnetic field within a pilot-scale hydroseparator was obtained by installing a magnetic grid within the device. The test parameters for the pilot-scale study also included the effects of magnetizing/demagnetizing the feed and magnetizing current. Magnetic iron losses were substantially reduced, even when the hydroseparator was operated at very high upward velocities. Results also show that increasing the field strength decreased the losses, but magnetic enhancement was successful even at the lowest field strengths, and the results show that magnetic iron losses were lower when the feed was magnetized. Key words: Hydroseparator, Magnetic field, Magnetic grid, Taconite processing, Magnetizing, Demagnetizing.

Jan 1, 2003

By L. Piga, P. Cipriani, F. Pochetti

High-temperature roasting of alunite in the presence of K2CO3 gives rise to a reaction that results in up to an 80% recovery of its potassium content as K2SO4 by leaching of the roasted mixture. K2SO4 is also generated from the reaction between the added K2CO3 and the SO3 driven off during roasting of the alunite. This limits the environmental and corrosive problems involved in the thermal treatment of this mineral. A solid residue containing mainly aluminum oxide is also obtained. This could be used as raw material for the production of aluminum, as the use of K2CO3 does not introduce different cations than are in the ore. A statistical study was performed on the factors assumed to affect the recovery of potassium, namely, roasting temperature, K2CO3- alunite stoichiometric ratio and leaching temperature.

Jan 1, 2000

By Orville A. Derby

In view of the recent important discussions before this Institute on the genesis of metalliferous deposits, certain features in the occurrence of gold which seem to be more clearly developed in Brazil than elsewhere can hardly fail to be of interest. As the observations here recorded have necessarily been of a somewhat cursory character, they will be presented in the form of brief notes, without any attempt to draw conclusions as to their genetic significance. Gold in Gneiss.—The statement made by me many years ago† that in the districts of Campanha and S?o Gongalo, in southern Minas Geraes, gold occurs in gneiss, can now be reaffirmed in the most positive manner, on the strength of a recent examination of fresh material, confirmed by the testimony of an experienced mining captain from the Morro Velho mine, who, being skeptical on this point, made a prospectingtour in the district. The specimens examined, though so far decomposed as to be readily disaggregated, were clearly of

Jan 1, 1903

By Raymond S. Shrode

Limestone and dolomite production is of significant importance to the Baltimore and Ohio Railroad. Except for coal, more tons of limestone and dolomite are moved by the Railroad than any other mineral raw material. In the territory served by the Railroad, these materials are produced from every geologic system from Cambrian through Pennsylvanian. Some of the operations produce premium stone acceptable for high-specification steel and chemical use; at others, the stone finds application as aggregate materials and for cement manufacture. The Railroad is interested in seeing continued production from the operations it now serves, and in serving operations in a way mutually beneficial to the Railroad and to the producer. In working with producers, the importance of geologic knowledge in prospecting and development of deposits has been clearly recognized. In turn, knowledge of the economic and technological facets of production and consumption is needed for the geologists to participate with maximum efficiency.

Jan 1, 1966

By B. R. Reddy, Y. V. Swamy, B. V. R. Murthy

Chromitiferous overburden containing nickel in oxide form is reduced with CO-CO2-N2 gas mixtures. This converts the nickel oxide to metallic nickel and restricts the iron oxide to the magnetite state to extract the nickel. Reduction experiments were carried out on 500-g samples in a bench-scale vertical reactor. The tests were run to establish the process parameters, including the optimum partial pressure of CO, the reducing gas flow rate, granule size and roasting time. The reduced calcine is then subjected to an ammonia-ammoniacal carbonate leach to extract nickel selectively as its amine complex. More than 90% of the nickel could be extracted with a volumetric CO/(CO+CO2) ratio of 0.57 at 750°C and a roasting time of 90 min. The addition of 2.5% (by weight) charcoal to the granules improved nickel extraction by 11 % to 19%. Nickel leaching efficiency with ammoniacal solution is compared to the bromine-methanol method.

Jan 1, 2000

The increasing introduction of high capacity mechanical equipment into the coal mines of New South Wales following. tforld War II brought with it problems of roof support. Rapidly advancing headings in difficult country could not be supported with heavy, close,timbering due to the time involved in installation and the reduction of available' space for the movement of machines. _ The installation of low cost, space saving, rapidly installed roof supports became a necessity if the new mechanical equipment wa-s to be allowed to operate at maximum efficiency. As, a result of experience in the United States of America, the system of roof support using steel reinforcing bolts began to find increasing, popularity in the mechanised mines in this State. From the somewhat'crude methods of in- stallation adopted in some of the, early trials, the practice of roof bolting has advanced into a-highly technical operation, requiring care and skill to ensure optimum results.

Jan 1, 1971

By Jiun-Yih Chen

Pile load tests are regularly used to verify pile capacities. Sometimes, they are used to optimize pile designs. This paper presents a case study based on a real project, in which the information obtained from load tests during construction was used to shorten the design pile lengths without a formal decision analysis. In this study, a simple probabilistic model was used to assess the probabilities of failure based on design information. The Bayesian approach was used to update the probabilities given the additional information from load tests. These probabilities were then used in a formal decision analysis to determine the optimal pile lengths based on design information and based on the additional information from load tests. The optimal pile lengths are different from those implemented in the project without a formal decision analysis. The value of the formal decision analysis is illustrated by its ability to optimize the pile length in a transparent and defendable way.

Jan 1, 2009

By Francisco Cadena

THE construction of Norris Dam, built by the Tennessee Valley Authority on the Clinch River, a tributary of the Tennessee River, involved the production of coarse and fine aggregate for approximately 1,000,000 cu. yd. of concrete; A hammer-mill plant for the manufacture of sand from quarried rock was indicated as the most economical method of providing this material. The abrasive character of the feed as compared to the average hammer-mill feed made it necessary to control operations rather closely, and this resulted in the accumulation of many data bearing on production and maintenance. This paper will deal only with three specific sets of data, accompanied by such general infor-mation as miry be necessary to explain the conditions under which they were obtained and followed by discussions on the relation of silica content to hammer wear, comparative costs of slugger and stirrup hammers, and comparative costs of tool-steel and n manganese-steel grate bars.

Jan 1, 1937

By H Durrant, P I. Corke, J Cunningham

This paper reviews the state-of-the-art in the automation of underground mining vehicles and reports on the development of an autonomous navigation system under development through the CMTE with sponsorship arranged by AMIRA. Past attempts at automating LHDs and haul trucks are described and their particular strengths and weaknesses are discussed. The auto-guidance system being developed overcomes some of the limitations of state-of-the-art prototype æcommercialÆ systems. It can be retrofitted to existing remote controlled vehicles, uses minimum installed infrastructure and is flexible enough for rapid relocation to alternate routes. The navigation techniques use data fusion of two separate sets of sensors combining natural feature recognition, nodal maps and inertial navigation techniques. Collision detection is incorporated and people and other traffic are excluded from the tramming area. This paper describes the work being done by the group with regard to auto-tramming and also outlines the future goals.

Jan 1, 1998

By Nexhmedin Lohja

The production of high-carbon ferrochromium in a submerged electric furnace based on double-level technology has some advantages compared to close-type furnaces with one tap hole. These advantages include the reduction of the specific energy consumption for the overall process, good separation of ferrochromium from slag, an effective treatment of raw materials including lean chrome ores (low percentage of Cr2O3) etc. An outline of the operation of this furnace along with the production line of briquettes from fines of chrome ore by using organic and inorganic binders, will be followed by a description of the recent work carried out to improve the energy consumption in this furnace through a pre reduction process of Cr2O3 ores by the off-gas energy recuperated from the furnace and the use of SiC in the feed. A short theoretical analysis of the new work will also be given.

Jan 1, 2006