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By F. H. Deily

The petroleum industry has developed and utilized many aspects of rock mechanics, both in its search for petroleum and in its drilling and production operations. Geological exploration activities have been improved by knowledge of earth tectonic forces. Better understanding of seismic wave motion has contributed to a more accurate interpretation of geophysical data. Drilling activities have benefited from basic knowledge of rock strength behavior under in situ conditions. Production has been significantly increased through stimulation techniques, such as hydraulic fracturing. The ability of rock mechanics work to contribute to future petroleum activities will depend upon the development of knowledge of rock properties under greater depths and at higher pressures and temperatures.

Jan 1, 1969

By V. K. Kakaria

As you know most of the gold and silver is produced by one of the following processes: (1) Agitated Leaching - Carbon adsorption or Merrill-Crowe (2) Heap Leaching - Carbon adsorption or Merrill-Crowe The figure 1 shows a typical flowsheet for recovery of gold and silver using Agitated or Pachuca Leaching Operation. The ore is crushed and ground and then leached in cyanide tanks solution using either Pachucas with air agitation or tanks with mechanical agitation. The soluble metal values are separated from the pulp by counter-current washing. The precious metals from cyanide solution are either recovered by zinc dust (Merrill-Crowe Process) or by loading on carbon and stripping with hot caustic cyanide solution. Gold and silver are electrowon on steel wool cathodes.

Jan 1, 1981

By Karl S. Vorres

Coal my not seem like it, but it is a perishable commodity. The basic coal scientist cannot always replicate earlier experiments with a given sample because of changes that have taken place in the sample. This has led to a stated need for stable samples Coal looks like a uniform black solid to many people, but it does vary in its composition from state to state and mine to mine it also can be shown to vary significantly within a mine or seam. These variations have led to a stated need for consistent samples.

Jan 1, 1985

By C. Leal

Modern production has as goal to reach high and uniform quality in their products. To success with this, it is essential to have a good knowledge of the different variables involved in the process. Investigation or analysis of a process or system has as references the measurements of the variables. These measurements are presented normally in form of data. These data are measured in intervals over time. The aim with measurement of the data in a process is to obtain information about the state of it in order to have it under control. Other goal is to know how the results are affected by the process variables to improve upon product quality, redunding manufacturing cost, better pollution control etc.

Jan 1, 1994

By George C. Carter

It was just a little over three years ago that the "Go" button was pushed to start operations on the blending piles at Oro Grande. As is usual with any new installation, there were problems that had to be solved. This paper will concern itself with those problems directly related to quality control. To obtain a consistent outgoing quality level at the most economical level for a finished product requires two main points: 1. Measurement of variations in the process, 2. A method of making a predictable change to adjust for variations. The manufacture of cement requires a relatively high degree of accuracy if a consistent outgoing quality level is to be maintained. The blending piles were our solution to this problem.

Jan 1, 1962

By James L. Patton

Automation of mining increases the productivity of labor, thereby reducing the unit cost of labor. Such cost constitutes the largest portion of the direct or variable costs of producing coal. Therefore, any increase in productivity directly reduces variable cost. The large investment in mechanical equipment carries with it the burden of increased fixed charges. As the proportion of fixed cost to the total cost increases, the effects on the cost of production changes are amplified. Therefore, equipment must be fully utilized at all times. Averaged fixed costs rise with any decline in production. Such a situation forces coal companies to seek every means of main¬taining full production. Figure I will reflect the story on the relationship of production to cost.

Jan 1, 1962

During the past decade, international mining companies have descended on South America. Countries like Chile, Brazil and Peru have seen billions of dollars in exploration and development funding turn their once meager mineral industries into mining giants that have become the envy of the world. Part of this outpouring of foreign investment in those countries has been because each has privatized its state-owned mining companies and has liberalized its foreign investment laws. In addition, they have rewritten their mining codes to encourage minerals development and passed new tax laws that have made natural resource development more attractive. Now these same international mining companies are turning their attention to Argentina. This a country that, like Chile, Brazil and Peru, has a wealth of largely un- tapped mineral resources. And Argentina wants its share of the foreign investment that its neighbors have enjoyed. With that in mind, ministers of Argentina's natural resource agencies came to Denver, CO to meet with mining executives and pitch their country's mining industry. The meeting, attended by about 200 people, was sponsored by the US Trade and Development Agency and organized by the World Trade Center Denver. Others involved were the Colorado Mining Association, the Colorado International Trade Office and the Secretariat of Industry, Commerce and Mining of Argentina. The following is a summary of a report on Argentina's mining industry. It was prepared by Anderson & Schwab Management Consultants and distributed to attendees as part of the meeting's program.

Jan 1, 1998

By Wen H. Su

Extensive investigation has been conducted to determine the causes of a series of roof falls occurring in a room-and-pillar working located in southern West Virginia. Underground observation, along with laboratory testings and finite element analyses were conducted to search for possible mechanisms for the roof falls. Results of the investigation have led to a better understanding of the mechanisms involved in the roof falls. Necessary modifications of mine layout and roof support plan are proposed for improving safety and profitability at the mine.

Jan 1, 1984

By Henry W. Brandt

What is the most practical method for storing a huge quantity of crude oil for a long period of time to assure availability if conditions curtail the source of supply? Underground storage is a logical answer. But can abandoned mines be used for this purpose? That is the proposal Fenix & Scisson International, Inc. submitted to the S.F.F. Association (acting in behalf of the Department of Industries of the Republic of South Africa), Johannesburg, South Africa, in October 1966. This engineering and contracting firm with headquarters in Tulsa, Oklahoma, specializes in underground storage; and based upon previous experiences their engineers were reasonably certain that a mine could be used for storing crude oil. The answer subsequently proved to be "yes." The result was con- version of a coal mine to provide storage for a quantity of crude oil which is the equivalent of a sizeable oil field. The total cost of purchasing, testing, and converting the mine was less than 15 percent of the cost of conventional steel tanks. Operating and maintenance costs are proving to be about 2 percent of those experienced at two large tank farms owned and operated by the Association.

Jan 1, 1973

By Darrell V. B. . McClarty

In 1996, Rio Algom, Denison Mines and the Elliot Lake Research Field Station (ELRFS) formed a consortium to implement a regional environmental information management system (REIMS) for the Elliot Lake area in Ontario, Canada. ELRFS is an affiliate of Laurentian University in Sudbury, Ontario, The discovery of uranium in the Elliot Lake region in post-World War II led to the development of 12 mines and 11 associated mills between 1955 and 1958. During the late 1980s, declining world demand for uranium, combined with the discovery of high-grade uranium ore in other areas of the world, made the Elliot Lake mines uneconomical. As a result, all area mines ceased opera¬tions by the end of 1996. The eight facilities and three tailings management areas operated by Denison Mines and Rio Algom's five mining waste management areas contain 150 Mt (165 million st) of potentially acid-generating tailings. The areas cover 13.2 km2 (3,265 acres) and receive drainage from an additional 13 km2 (3,212 acres). The primary objective of the joint initiative was to implement a personal-computer-based, regional, environmental-information management system for managing historical data and ongoing environmental programs in the Elliot Lake region. The Elliot Lake consortium decided it needed an information system with an integrated, process-oriented and requirements-driven approach to collect and manage the environmental information. Following a study of environmental information management systems currently used by the mining industry, the consortium decided to base REIMS on the "Envista" product. This is a commercially available, environmental information management system marketed by Envista Technologies of Saskatoon, Canada.

Jan 1, 1999

By D. P. Harding

Quick, inexpensive and accurate mineral-phase identification is of utmost importance to applied mineralogists. The precise relationship between the intensity of measured backscattered electrons in a scanning electron microscope and the average atomic number of the specimen is still argued. Nevertheless, much can be gained by using backscattered electron images to identify mineral phases in a specimen. An application was developed to facilitate this method and makes it a practical, inexpensive and valuable option in many mineralogical investigations. Keywords: Mineral identification, Scanning electron microscope, Backscattered electron detectors

Jan 1, 2003

By C. Klauber, H. G. Linge, W. G. Jones

The carbon-in-pulp process for gold processing depends on the adsorption of dissolved Au(CN)2- from solution onto activated carbon. Our work shows that coconut and peat based carbons have the same mechanism and kinetics of adsorption. There is no contribution to the bonding from carbon-oxygen functionalities on the carbon surface, as has been invariably supposed in all previous theories for the mechanism of the reaction. It is shown that Au(CN)2- is reversibly adsorbed intact on, and parallel to, the graphitic planes of the carbon. The physiochemical basis of the measurement of carbon reactivity for gold adsorption is discussed.

Jan 1, 1989

By Francis G. Stehli

Though sedimentary rocks comprise only about five percent of the volume of the continental crust, they cover about 80% of its surface, serve as important reservoirs for fluids, contain reserves of non-metallic minerals, and have in general been extensively drilled. However, most drilling has been shallow in comparison to the thickness of the crust and such deep drilling as has taken place is very strongly localized in sedimentary basins. This may be seen by reference to Figures 1 and 2 which show the location of wells that drilled deeper than 15,000' [=] 4.6 km. (Figure 1) and those that drilled below 20,000' [=] 6.15 km. (Figure 2). It is apparent that, even in regions of sedimentary cover, direct exploration below six kilometers has been very restricted. In the case of the metamorphic and igneous rocks which make up 95% of the volume of the crust, direct exploration has been much less extensive in terms of both area and depth. The present state of our knowledge of the crust below a' thin surface layer stands in marked contrast to our growing present need for raw materials and the needs of future generations. It also stands in contrast to our need for enhanced, scientific knowledge of the deeper crust, its configuration, its present state, its hydrothermal systems,-its evolution, and its materials. Lessons learned in exploring the third dimension of the sea floor, the vigorous prosecution of seismic profiling, the development of testable models for hydrothermal systems and mineral deposits, the need for better understanding of heat flow, state of stress, earthquake mechanisms, and a host of other phenomena all suggest that it is time to launch a national program for scientific exploration of the crust which uses drilling to test important hypotheses developed on the basis of indirect evidence.

Jan 1, 1985

By Benjamin K. Pocock

When considering alternative equipment choices in mill or process flowsheets, it is important to determine both capital and operating costs of such equipment as well as other possible savings related to downstream operations. This paper presents a few case studies and shows cursory guidelines for the selection of equipment for new installations or in the retrofitting of existing plants. Based upon recent plant experience, suggestions are given to improve the operation of clarifiers, thickeners and vacuum filters.

Jan 1, 1986

By A. P. Massmann

Design for economical operation, minimum operating labor and minimum maintenance for labor and supplies are virtually inseparable. Each consideration has a vital bearing on the other. Let us assume that we have the design complete for the most economical operation with a minimum of operating personnel. This means, in addition, that we have the fewest number of operating units consistent with the product requirements for a team or metallurgical coal which we are called on to produce. The number of units will vary greatly, being influenced by design, washability characteristics, tonnage and degree of quality control necessary by reason of producing a product for metallurgical, steam or domestic use. The units involved most ordinarily for any type coal preparation plant will number as a minimum the following: 1. Hoppering R.O.M. Coal 2. Feeding

Jan 1, 1959

By Matthew Spedding

The complex nature of the carboniferous measures prevailing in the U.K. has dictated the types of mining required to exploit the coal seams. Most mines in Britain are referred to as deep mines in the sense that they operate at depths of 1800 - 3000 feet. The main system of coal transport to the surface is by vertical shafts which intersect the workable seams which at times number between 4 and 5. As mining has been practiced in most of the major coalfields in the U.K. for well over 100 years, with the initial extraction of the shallower and more profitable seams, the present management have been left a legacy of indiscriminate extraction which severely hampers their efforts to maximise the mine layouts. There is no single standard design of mining layout capable of meeting the wide variety of conditions which exist in the British coalfields. Mining layouts are subject to fixed and variable parameters. In discussing multi-seam working, the main parameter must be the effect of old workings above and below the seam to be extracted. There is a distinct lack of reliable information which would enable layouts to be designed to completely avoid or control these destructive forces. The guidelines are, therefore, mostly empirical.

Jan 1, 1977

By T. W. Newell

Small tonnage ore bodies can be developed at a profit on a short life basis. Such is the case of the Bardon Mine in. the Big Indian Mining District in San Juan County. Utah. Faced with a small initial tonnage of high grade uranium ore, the Shattuck Denn Mining Corporation Engineers developed some new ideas for sinking the shaft and planned extraction to warrant the capital risk to mine a limited reserve. The Bardon Mine is located fifty miles southeast of Moab, Utah in the south end of the Big Indian Mining -district. Shattuck Denn Company, a wholly owned subsidiary of the Shattuck Denn Mining Corporation, manages and operates the property under an operating agreement with Kerr-McGee Oil Industries, Inc. of. Oklahoma City. Oklahoma, and Anderson Development Corporation of Albuquerque, New Mexico. Based. on Kerr-McGee drilling., a tabular ore body about 350 feet long by 250 feet wide with an average thickness in excess of seven feet was indicated.- The ore body strikes easterly-westerly and dips from nine to twelve degrees to the south. Uraninite is the dominant uranium ore mineral associated with vanadium. The ore occurs in an arkosic conglomeratic sandstone with some interfingering of mudstone and shale in the Mossback member of the Chinle formation in contact with the underlying Cutler formation. The ore horizon is overlain with 40 to 60 feet of mudstone and shale. Fortunately, the back. immediately over the ore is a reasonable competent shaley sandstone which has made a fairly good. environment for roof bolting.

Jan 1, 1960

By M. Polat, G. Ahuja, S. Chander, M. S. Klima

A study was conducted to investigate the use of flotation in combination with dense-medium cycloning utilizing ultrafine (-10 um) magnetite, as an integrated process for high-efficiency cleaning of fine coal. The objective was to produce a high-quality (low-ash, low-sulfur) coal, while reducing the amount of non-magnetic material that would need to be removed by magnetic separation. Three dense-medium cyclone tests were performed using different underflow diameters to produce feed material for the flotation separations The use of different underflow configurations caused a variation in the pulp and solids splits, which changed the clean-coal yield and the magnetite-to-coal ratio of the cyclone products, and hence, the composition of the flotation feed. Flotation was used to separate the clean coal and to recover the magnetite contained in the cyclone overflow stream. Any ultrafine refuse material, which may have reported to the cyclone overflow stream, was also removed in this step, further upgrading the product. In addition, flotation was used to improve the overall yield by recovering a middlings fraction from the cyclone underflow stream. It was found that flotation was very effective in separating the coal (or middlings) from the ultrafine magnetite, even under variable feed conditions. Magnetite recoveries approaching 99% were possible using rougher-cleaner separations in a laboratory flotation cell. This paper presents the results from this study.

Jan 1, 1995

By J. W. Oberholzer, C. F. Meyer

The increased use of continuous miners to extract thicker coal seams has necessitated the use of enhanced ventilation systems in the headings. Due to the increased face size, more ventilation is required to effectively dilute the liberated methane down to acceptable levels. If more air is directed to the face an increase in the entrainment of dust creates an increased potential for workers to be exposed to dust. To enable the ventilation systems to reduce the methane levels and the levels of the airborne dust the ventilation systems in the heading have to be carefully designed. The matter is made more complicated through the use of other ventilation methods like jet fans, air-moving sprayfans on the continuous miners and high capacity scrubbers on the continuous miners. To enable the design of a balanced ventilation system in seam heights of over five metres requires methods that consider the system in a three- dimensional manner rather than in a two-dimensional fashion. Through the use of computational fluid dynamics (CFD) coupled with appropriate methods of taking underground face ventilation readings these problems can be solved in a cost effective way. Using computer modelling, ventilation methods can be designed and assessed instead of using costly underground trials to test the alternatives. Use of this system has led to a higher level of ventilation design as well as a more effective method to combat the health and safety hazards in coal mine headings.

Jan 1, 1995

By Tzou-Shin Ueng

Rock reinforcement of rock anchors and rock bolts are commonly used for the support of large rock caverns. The rocks at the location of most large underground openings are usually under very high initial stresses prior to excavation. Hence, the stress redistribution caused by excavation will induce considerable rebound deformations of rocks surrounding the caverns. Since the pressures exerted by the reinforcement are generally far below the initial rock stresses, the reinforcement will be stretched along with the rock deformations, and the stresses in the reinforcement increase accordingly. It is not uncommon for the stress in the reinforcement to reach the yield strength, and in some cases the reinforcement may even have failed. Therefore, the increase of stresses caused by the rebound deformations of rocks should be taken into account in addition to the force required to stabilize the caverns. It was found that the measured stress increases of the prestressed tendons after installation were in good agreement with those computed based on the measured rock deformations between surface and the anchoring point of the reinforcement. The rebound rock deformations and the stress increases in the reinforcement can be estimated based on the results of the finite element analysis and experiences in previous field measurements incorporated with considerations of the geologic conditions, rock properties, rock reinforcement and construction procedures.

Jan 1, 1986