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By Y. Topkaya, R. E. Johnson, D. Buttinelli, B. R. Palmer, A. Geveci, L. Stoppa, C. Lupi, F. Pochetti

Representative samples of a composite mixture of three typical Cu/Zn complex sulphide ores, namely Black-, Yellow- and Altered-ore, from the Cayeli deposit in Turkey, were used for leaching tests in 2.2 M FeCl3, or 1 M CuC12-2 M NaCl solution in the temperature range from 313 K to 363 K (40O to 90O C), with and without the presence of an organic solvent for elemental sulphur, such as CCl4. The leaching rates of copper and zinc were quite high, as expected, in FeCl3 solution and complete recovery of both metals was obtained at the highest temperature when the solvent was present. However in CuC1, solution, extraction yields of the order of 95% only for Cu and Zn were achieved and the positive effect of the solvent was not clearly shown. The kinetics curves of Cu leaching by FeCl3 indicated a model of reaction rate depending on the particle surface, as in a chemically controlled reaction, in tests with the presence of CCl4. Without the solvent, or in CuCl2 media, the model of the diffusion controlled reaction seemed to prevail. Values of apparent activation energy, in both of the leaching processes, were determined and compared with those reported in literature.

Jan 1, 1993

The Pittsburgh (Pa.) and Spokane (Wash.) Research Laboratories are among the world?s foremost mining research establishments. Once a part of the former U.S. Bureau of Mines (USBM), which was abolished by the U.S. Congress in fiscal year 96, health and safety research at these laboratories was transferred to the National Institute for Occupational Safety and Health (NIOSH). NIOSH is the Federal agency responsible for conducting research and making recommendations for the prevention of work-related illness and injury. The Institute is part of the Centers for Disease Control and Prevention within the U.S. Department of Health and Human Services. Over the past two decades, the Pittsburgh and Spokane Research Laboratories have produced sustained technological achievements in mining health and safety, including? ? Development of novel respirable coal dust control technologies and more effective monitoring techniques to reduce worker exposure to hazardous mine dusts. ? Improved ground control technologies to warn and protect miners from the dangers of coal mine roof collapses and other hazardous strata conditions. ? Improved ergonomic design criteria and training methods to protect mine workers from injuries and fatalities associated with equipment and manual tasks. ? Development of enabling technologies that allow miners to control their mining equipment from a physically safe, protected work area away from respirable dust, harmful noise levels, and roof collapses. ? Improved mine fire detection and extinguishment techniques. ? Development of smaller, lighter, and safer emergency breathing devices.

Jan 1, 2007

By Klaus W. John

The geologic factor of greatest significance in rock mechanics and rock engineering is considered to be the geologic structure represented by joints, faults, and other planes of weakness. This geologic structure differentiates between the rock element and the rock system composed of these elements. Only during the last decade has the difference of the technological properties of element and system been recognized but this appears to be more in theory than in engineering practice. If rock mechanics is to achieve real significance in engineering practice, it has to provide methods of analysis which are realistic compromises between the best representation of the actual conditions and pragmatic engineering. The rock mechanics practitioner has to face the fact that many geological engineering and rock mechanics problems may be too complex to allow rigorous analysis but at the same time are deemed satisfactory for the construction of major structures. Ultimately, the geotechnical engineer or the engineering geologist has to express the effect of geologic factors in quantitative, even if approximate, terms and provide numerical data on strength and deformability of rock systems to be utilized in construction. Qualitative evaluations, quantitative descriptions of geologic features as such, and comparisons of specific test results are always of interest but may not suffice as basis for engineering decisions and designs. The present efforts of the rock mechanics group at the Karlsruhe University, Federal Republic of Germany, are based on a systematic combination of geomechanical models and numerical analyses based on the finite element approach. This group considers that at the present stage

Jan 1, 1970

By Alex Moyano

Due to very demanding environmental rules, and to the incrementing impurities contents in the processed concentrates, Codelco Norte smelter permanently faces new demands for planning the production program with the present fulfillment of the environmental regulation. Accordingly, the CN smelter along with IM2, developed an impurity distribution simulation model, M-DICE, which predicts the impurities behavior for each of the process units of the smelter under different process configurations and concentrates quality. The development of the M-DICE included the gathering of operational data for the process units of the CN smelter, including temperature, oxygen enriched air, matte grade, etc. Then based on a mass balance for each of the process units involved in the smelter a thermodynamic evaluation was done to derive the arsenic fractional distribution among the condensed (matte/white metal/copper/slag) and gas phases. Then, the validated M-DICE was able to predict the arsenic behavior in the Teniente converter processing complex concentrates with high arsenic content, among others. At present, M-DICE is in its last stage of development, and is expected to be a suitable environmental and process management?s tool for the Codelco-Chile?s smelters.

Jan 1, 2006

By E. T. Turkdogan

This paper deals with an analysis of the conditions leading to the formation of blowholes and surface and subsurface defects in cast low-carbon steels. The theoretical analysis of the problem is based on the concept of the occurrence of deoxidation reactions during cooling of liquid steel and during its solidification. The reaction equilibrium data are given on deoxidation of steel by carbon, silicon, and manganese. The details of the calculations are given on the simultaneous deoxidation of steel by silico-manganese additions to produce a desired level of deoxidation at certain residual concentrations. Based on an idealized model, an attempt is made to calculate the enrichment of solutes in the solidifying liquid entrapped within the interdendritic cells which are known to be less than 200 µ thick. Formulae are derived for the calculation of the change in the residual oxygen content of the enriched liquid steel, controlled by Si/Mn deoxidation. It is shown that for every particular initial silicon, manganese, and oxygen concentration in steel (as residuals in liquid solution at the beginning of solidification) there is a particular carbon concentration below which carbon monoxide, leading to blowholes or pinholes, is not expected to form. There are a number of independent variables which have a decisive influence on the formation of blowholes. For example, it is shown that the position of the curve depicting the critical relation between initial silicon and carbon content for suppression of the evolution of carbon monoxide) can be shifted to lower silicon or higher carbon levels by: increasing manganese content; decreasing oxygen, hydrogen, or nitrogen content; or increasing external pressure on the solidifying mass. FOR the production of sound castings it is essential to prevent the formation of interdendritic worm-holes or pinholes brought about by gas evolution during solidification. Another major problem encountered in solidification of ingots is the formation of surface defects. These problems are thought to be closely associated with the deoxidation reaction occurring in liquid steel during cooling and subsequent solidification. As the liquid becomes richer in impurities during dendritic solidification of steel, a series of reactions may occur in the liquid phase trapped within the branches of growing dendrite platelets. Because of the strong interaction between dissolved oxygen and impurities in liquid steel, the reactions most likely to occur are of the deoxidation type. However, inherent to the extreme complexity of the problem in question, numerous simplifying assump-

Jan 1, 1965

By H. E. Blake

An evaluation was made to determine the economics of utilizing waste fluosilicic acid for production of (1) calcium fluoride, and (2) anhydrous hydro-gen fluoride. Two versions of each process were considered and compared. The evaluation showed that both products could be produced and marketed competitively. Lowest estimated product sales prices required to yield a 25-percent return on investment before taxes (discounted cash flow basis) was $339.34 per ton of hydrogen fluoride and $48.64 per ton of calcium fluoride.

Jan 1, 1971

By Thomas L. Watson

A part of the field-seasons of 1900, 1901 and 1902 mas devoted by the writer to a study of the manganese ore-deposits of Georgia. A report embodying the results of this study is rapidly nearing completion, and when finished it will be published as a bulletin of the Geological Survey of Georgia. I believe, however, the importance of these deposits warrants a separate and earlier publication than that made possible by the Survey, in which the more important results of the study are briefly set forth. It is principally for this reason that the present paper has been prepared. Previous Work.—Some of the more important deposits of manganese occurring in the Paleozoic area of Georgia were studied to some extent previous to 1890 by Dr. Penrose;t and again in the early nineties by former State Geologist, J. W. Spencer. In a recent paper published in the Transactions, on the " Geological Relations of the Iron-Ores in the Cartersville District, Georgia," Dr. Hayes briefly mentions the manganeseores of the same district. Distribution of the Manganese-Ores.—Georgia is divisible into three geologically-distinct areas which, named in order from southeast to northwest, are (a), the Coastal Plain; (b), the Crys-

Jan 1, 1904

Jan 1, 2004

By Alex Lowson, Dan Tempelis

The Riverside Badlands Tunnel segment of the Metropolitan Water District of Southern California’s Inland Feeder Project, was lined with a segmented concrete primary lining and a welded steel final lining with the annulus filled with Low-Density Cellular Concrete (really a grout). The paper describes a numerical modeling technique that was developed to determine safe grout placement procedures to avoid pipe flotation, and shows the relationship between flotation and the rheology of the liquid grout. Design details of the steel liners are often not well suited to grout placement, and recommendations are given on how to improve this.

Jan 1, 2003

In spite of our deep conviction that it would be wrong for the United States to enter World War II, when, after Pearl Harbor, we were actually in it, I felt that I must do all I could to help. The country had been so good to me that I could not decently stay on the sidelines. My first thought was that I might help with supply and administration in the Air Force, as in World War I. So on the evening of Pearl Harbor I wired the chief of our Air Force in Washington saying that I had been on Gen. William Mitchell's staff in World War I and was offering my services again. I received a noncommital answer, but after a couple of weeks was told to take my physical examination. I passed it, but nothing further happened. After helping to make plans for the wartime operations of Summit King and Desert Silver, Dorothy and I went to New York to spend Christmas with Molly and Peter, both of whom were in college in the East. I had to complete a report on the Argonaut mine in California first, though the war made my recommendations of dubious validity. Before Christmas I received wires from Temple Bridgeman, Phil Wilson, and other friends who had taken positions with government agencies responsible for securing mineral products needed for war use. They urged me to join them. It was evidently a case of not whether but how I could be most useful. After six uncertain days with the family in New York I took the night train to Washington on the 28th of December. I had a hectic day there. First I saw Arthur Bunker and Phil Wilson at what became the Aluminum and Magnesium Division of the War Production Board. Their office was in an old converted barracks. They asked me to examine magnesium deposits in Nevada at once, and then to look at other magnesium and aluminum properties. After leaving

Jan 1, 1976

By H. W. Smith, A. K. Bjerring

A nonlinear dynamic model for a flotation cell is developed, using a number of simplifying assumptions, the most important of which is that of essentially complete liberation in the feed material. Using this model, a complete dynamic model for a flotation circuit is developed and calibrated against steady- state process data. The dynamic response of the circuit to disturbances in input feed rate and composition is simulated, as is the response of a linearized and simplified model on which control design might be more easily based. Preliminary results indicate the practicability of the modeling technique. However, difficulties in matching steady-state operating conditions in one process stream, and the apparent importance of recycle streams as indicators of process operation, indicate that inclusion of at least one species of middling particle in the model should be considered.

Jan 1, 1969

The first Mine Rescue Performance Evaluation for mine rescue teams was held just prior to the 1992 RMCMI convention meeting schedule on June 27 and 28. Six teams took part in this year's evaluation; Decker Coal, Decker, Montana; BHP Minerals' White Team and BHP Minerals' Purple Team, both of Aztec, New Mexico; Kerr McGee Coal Corporation, Jacob's Ranch Mine, Gillette, Wyoming; The Coteau Properties Company, Freedom Mine, Beulah, North Dakota and The Falkirk Mining Company, Falkirk Mine, Underwood, North Dakota. This was the first mine rescue evaluation program developed to measure a unit's proficiency in their skills rather than emphasis on a ranking order of teams. The objectives for the evaluation were to promote learning and to evaluate the current level of experience of the attending rescue units. The priority goal for this evaluation was to recognize current rescue skills, knowledge and abilities of each team participating. In doing this, each team is provided with individual evaluations and a path for improvement as needed. [ ] Realistic industrial related scenarios, closely simulating the stress of actual rescue incidents, was provided by members of the Hermosa Cliffs Colorado Fire Department under the direction of Dan Noonan, Fire Chief. On Saturday, June 27, five rescue scenarios were presented for each team to complete and on Sunday three of a more difficult nature were encountered by each team. On the final day of the RMCMI convention two of the teams performed rescue demonstra¬tions. Onlookers were afforded the opportunity to view the teams in action as they simulated actual rescue operations. The value and importance of mine rescue teams such as those participating in this year's Rescue Team Performance Evaluation are very evident as in many cases they are the only rescue personnel and medical staff on the work site in case of an emergency. Most of these persons are volunteers who spend many hours studying, practicing and perfecting their expertise in the lifesaving techniques needed in the event of a mine emergency. At the same time, they are very qualified coal miners who perform their respective duties at their mine locations, Their dedication to gaining the most knowledge they can get to handle these life and death situations is evident in their participation in evaluations such as this one. [ ] If a highly educational, informative, sharing of knowledge and expertise, while at the same time providing a very enjoyable experience, deems this evaluation a success ... the Rescue Team Performance Evaluation held during the RMCMI Convention at Tamarron this year was certainly a SUCCESS!! It is hoped that you can all enjoy this same experience with us next year! Linda G. Ash The Falkirk Mining Company [ ]

Jan 1, 1992

By J. B. Heslop, D. S. Bubar

"The Gondor Zn-Ag-Pb-Cu deposit is a stratabound massive sulphide lens occurring within Archean volcaniclastic rocks of the Yellowknife Supergroup. The deposit is located in the west-central portion of the Slave Structural Province, approximately 350 km north of Yellowknife.Initial diamond drilling at Gondor has outlined a steeply dipping, L-shaped, folded, massive sulphide body, which may be traced over a strike length of approximately 800 m, and to a depth of 350 m. True widths of up to 40 m have been intersected in the thickest part of the deposit. Preliminary estimates suggest that the deposit contains a minimum of 7.5 million tonnes grading 6% Zn, 50 g/tonne Ag and less than I% combined Cu and Pb. In addition, significant gold, grading up to 2.8 g/tonne, occurs in some parts of the deposit. The mineralization is open both down-dip and along strike.The Gondor deposit lies conformably within a predominantly east-west striking, north-facing sequence of felsic to intermediate volcaniclastic rocks. Coarse fragmental rocks are abundant in the hanging wall, whereas ash and lapilli-tuffs predominate in the footwall. The main structural feature in the area is a large-scale, steeply northeast-plunging, Z-shaped fold. The sulphide mineralization lies within the synformal portion of this fold, with the thickest part of the deposit coinciding with its hinge zone. Several episodes of faulting have also affected the local stratigraphy.The wallrocks of the Gondor deposit were hydrothermally altered prior to the onset of medium-grade regional metamorphism. A halo of altered rocks surrounds the massive sulphide lens, with no apparent difference in the degree of alteration between the hanging wall and footwall strata. The alteration zone is characterized by the addition of MgO and K20 and by the depletion of Na20 and CaO. These changes are reflected in the mineralogy of the altered wallrocks by local enrichment in chlorite, biotite, muscovite and cordierite.The mineralized zone is medium- to coarse-grained, well-banded and is composed largely of pyrite, quartz, and sphalerite with subordinate galena and chalcopyrite. Preliminary studies of metal distribution indicate that a lateral zonation is present, with lead enrichment in the central part of the deposit, and copper enrichment toward both ends. Stringer-type copper mineralization has not yet been discovered in the footwall of the Gondor deposit."

Jan 1, 1985

By Gilles A. Tremblay

Acidic drainage has been long recognized to be the largest environmental liability facing the Canadian mining industry and to a lesser extent the public through abandoned mines. The Mine Environment Neutral Drainage (MEND) Program was the first initiative formed in 1989 to develop scientifically-based technologies to combat acidic drainage. This 9-year volunteer program reduced the liability by several hundreds of million dollars and established Canada as the recognized leader in research and development on acidic drainage for metal mines. MEND 2000 is a three-year program that started in 1998. The key to MEND 2000 is technology transfer- providing state-of-the-art information and technology developments to users. MEND-developed technologies are being verified by long-term monitoring of large-scale field tests. Maintaining linkages with a number of foreign government and industry-driven programs is also important to the successful completion of the program. Through these efforts a further reduction of the environmental liability associated with acidic drainage will be realized.

Jan 1, 2000

HAVING already shown you the methods of making the moulds for casting and how they are to be prepared so that they may receive the melted metals well, it is now necessary, in order to complete the casting with perfection, that I show you not only the operations and instruments by which metals are softened, but also how metals can be made as liquid and fluid as water so they may easily enter into all the hollows of the moulds that you have made. Of these, besides the fire which is the prime agent, there is a very powerful furnace, which is called a reverberator.* I believe this is chosen not only for convenience but also because it is necessary in large casts. This is made of baked bricks, or of crude ones if desired or of suitable fire-resistant stones. Although all masters have the same objective, each one proceeds to make this kind of furnace according to his own ideas so that it can be said that there are almost as many different shapes of such furnaces as there are masters. This can be seen in the place that contains the metal, which is of such a shape that the force of the fire may operate better. Thus some masters are called good who, seeing no farther than what has been shown them, make them circular like a bread oven. Some others make them oval across the fire en- trance, while others extend them lengthwise. Also, there are some who make a single outlet for the flames, some two, and some three. Some make the entrance for the fire high and narrow and others, wide and low. The same is true of the place where the flames are generated, which is called the firebox. Some put the wood in from the side, some lengthwise in the same direction as the entrance for the flames, and some from above by means of a little hole. Also, one makes the vault low, and another makes it high. And while one puts an entrance for air underneath so that the

Jan 1, 1942

By David K. Denton

Results of the mineral resource study of the Upper Priest Lake RARE II study area indicate a low potential for the discovery and economic recovery of silver and lead in the Prichard Formation near contacts with the Kaniksu Batholith in the vicinity of the Mountain Chief Mine (fig. 1). Silver and lead minerals locally occur disseminated and in irregular quartz fissure-fillings in the Prichard Formation. Between 18^6 and 1967, 105 lode raining claims were located in the study area. The area was designated for "further planning" in the Final Environmental statement but was later changed to "nonwilderness" by President Carter after work was scheduled for the area.

Jan 1, 1981

By J. M. West

Expanded war in Viet-Nam overshadowed activities in the Far East in 1965, diverting capital and materials from potential regional development projects. Japan with-stood a period of business recession that was particularly felt by its coal mining and iron and steel industries. Toward yearend signs of improvement began to show. Despite the recession with attendant credit restrictions and forced cutbacks in areas of overproduction, Japan's overall industrial output rose nearly 5 percent during the year. Foreign trade, liberalized in 1964, was a strong point in the Japanese economy and took the place of lagging domestic demand. Japan maintained its third place in world production of iron and steel ahead of West Germany and in 1965 was the world's fore-most exporter of iron and steel in primary and semimanufactured forms. Economic setbacks in mainland China caused by its "Great Leap" failures and subsequent withdrawal of Soviet technical assistance were difficulties relegated to the past. However, a newly formed "Red Guard" political group, part of a so-called cultural revolution, was due to cause new disruptions in 1966. Nevertheless, significant gains were claimed in Chinese industry, and the country approached self-sufficiency in petroleum in 1965 by virtue of its Tach'ing oilfield. Restoration of friendly relations was achieved between South Korea and Japan accompanied by Japanese offers of industrial aid and increased trade. Indonesia's economy was deteriorating; the country withdrew from regional development organizations and continued its stubborn confrontation policy against Malaysia throughout 1965. Late in the year after a Communist uprising had been quelled, there was a period of political retrenchme t and it was hoped that economic improvements would follow. Petroleum remained a strong area in Indonesia's varied resources, and its production was increasing. Tin output declined, however, because of operating difficulties.

Jan 1, 1967

By C Adams

Reports of delays and cost blowouts in major study and construction projects are becoming increasingly prevalent in the resources industry. This is mainly being attributed to an escalating cost environment associated with the increased number of projects in the development to construction pipeline and a scarcity of competent skilled resources to deliver these projects. However, not all this effect can be directly attributed to the current environment. Historically the mining industry has not performed well in its ability to deliver projects according to the financial and physical parameters forecast in the feasibility study process. To manage the risks associated with delivery of major projects, resource companies need to ensure they use a standardised approach to management of their project development to satisfy project objectives and enable more efficient use of the increasingly limited available resources. Each discrete step in advancing the project from scoping study to operations needs to be integrated, reducing the amount of rework and duplication. This paper is primarily a consolidation of existing ideas on project management systems but also introduces new concepts to solve current issues. It describes the basic components of a typical mining project, the issues that commonly arise, the key attributes, and critical steps required for an effective integrated project management system covering projects from initial scoping studies through to project commissioning and operation. This paper focuses on technical study components of the mine development project with allowance for transitioning to design and construction and operation phases.

Jan 1, 2006

By Thomas P. Mahoney

Phelps Dodge Corporation's Tyrone Mine is a large open pit copper operation located in the southwestern corner of New Mexico. The Tyrone concentrator processes approximately 50,000 tons per day of copper ore. The waste ratio for this operation is 3:1; e.g., for every one ton of ore mined, three tons of waste material are also removed. This results in a mining rate of about 200,000 tons per day.

Jan 1, 1986

By Oleg N. Tikhonov

Control of ball mill grinding circuits is important due to the enormous consumption of electrical energy in mineral processing and other industries. Optimal control requires preliminary detailed studies of static and dynamic characteristics of the process. In this paper a study of nonlinear dynamics is presented with a view toward application to automatic control and the achievement of maximum grinding rate at minimal energy consumption. The study begins with Zagustin's equation (1935) of grinding kinetics [ ]

Jan 1, 1984