Search Documents

By F. Calizaya, I. Duckworth

An ore-pass is an underground conduit used to transfer ore from one level of a mine to another. This method of transportation depends on the elevation energy only; therefore, it has very low operating cost. However, two inherent problems may hamper this process: (1) hang-ups of interlocked pieces and (2) a sudden release of trapped air from the ore-pass (belching). These events can create unsafe conditions with the potential for catastrophic consequences. This paper presents a summary of CFD modeling studies that were formulated to investigate the pressure build-up and belching of dust and rock particles from long ore-passes. The models were calibrated against field data collected from an actual ore-pass system and used to predict the airflow-pressure distributions in the mine for various ore feed rates and ore-pass geometries. P.T. Freeport Indonesia’s Grasberg ore-pass system (240,000 tpd capacity) was used for this purpose. This system comprises of four active ore-passes, with each being more than 600 m in vertical length.

Jan 1, 2004

By L. G. Austin

The data of Dunn and Martin (1978) is reanalyzed using a rigorous application of Hertzian theory to the impact process. The Young's modulus of steel required to fit their data to the theory is a factor of about 10 3, too low compared to the values quoted for steels. Thus, doubt is thrown on the validity of their experimental technique, and it is possible that their values for maximum impact force and stress are far too low.

Jan 1, 2002

By Song Jiang, Xianzhi Tan, Minjie Lian

"The ground water heat pump system lades underground hot water which can be heated or cooled by heat exchanger in water source heat pump air conditioner. This system replaces the model of heating of air-conditioning by refrigerator and boiler. In this paper, the formation conditions of hot water energy in Shan Dong are analyzed in order to achieve the purpose of energy conservation and emissions reduction by taking full advantage of water resources such as water pouring and return water of beatification during the productive process of underground metal mine. In order to analyze the issue better, the paper points out some ways and methods for geothermal water often used in underground metal mine. This paper also presents the advantages of the technology of water source heat pump that is applied into underground metal mine. Here is a case study of comprehensive utilization of water source in a certain underground metal mine in Ji Ning. This mine, according to its own actual situation, designs heat pump heat exchange system which is used for indoor heating of buildings and bath for staff. It turns out that the system can save 23% water per year, cut down 3.303 million KW electric energy, and reduce 4160t emission of carbon dioxide. It is concluded that the technology of water source heat pump has broad application prospects in underground metal mine. Therefore, the results show that it is an ideal way to change the present structure of cooling and heating source in metal mine.Introduction In recent years, overuse of fossil fuels has posed a grave threat onto the environment, which makes renewable energy a more important status in energy structure. Development and utilization of renewable energy has become an important direction. Water source heat pump technology is to use solar energy stored in water as cold/heat source to convert energy. Currently, this technology has been widely used in some advanced countries. However, due to facers of implementation technology and component costs, there is still a gap in water source heat pump technology between China and these advanced countries. According to (Blum et al 2011) that after in-depth study, water source heat pump technology has developed rapidly in China recently, and the gap is gradually reduced. Groundwater source heat pump system as a kind of high efficiency, energy-saving and environmentally friendly technology in recent years, more and more get the people's attention. At the same time, its practical application has also been rapid development. Based on (Ni et al 2015) that According to the relevant departments of the prediction, the technology will become the 21st century the most efficient heating and cooling technology."

Jan 1, 2017

By A. K. Sheik, W. G. Pariseau

A small underground mine in northern Idaho was used as an experimental facility for studying the role of water in the analysis of mine-opening stability. Laboratory test data, borehole measurements and geological mapping assisted in the construction of a coupled finite element model of the rock mass. The model was used to make quantitative estimates of rock stress, strain and displacement changes and to make estimates of the water pressure and flow velocity changes that occurred during historical mining. Stope cuts and wet fills were included in the analysis. The stability of the crown pillars between stopes was of particular interest. The relatively low effective stress and high rock-mass strength showed that water pressure changes were of no great consequence, which is in agreement with experience. The computational tools used in the analysis may be applied to other wet mines with appropriate changes to site-specific data.

Jan 1, 2002

By Gerald M. Ellis

Introduction Gold exploration in the Dominican Republic has not received much publicity. The fact is, however, that a continuous program has been underway for some time. For the past two years, the Restauracion area of the western Dominican Republic, near the Haitian border, has been the scene of mineral exploration by the Dominican Department of Mines geologists, and later by geologists of Rosario Dominicana. The latter is a state-owned gold mining company and operator of the Pueblo Viejo open-pit gold mine. The exploration is for mineral deposits with the goal of finding another Pueblo Viejo-type deposit. Geology Exploration is being carried out in the western central Cordillera, the backbone of the Island of Hispaniola. Geology consists of quartz veins and veinlets and ramifying stringers carrying pyrite, barite, minor amounts of copper, and significant amounts of gold in places. They are associated with regional faulting in a complex of Cretaceous beds of andesites, dacites, argillites, siltstones, and shales. They are intruded by tonalites, diorites, and gabbros. Lesser amounts of zinc-lead mineralization occur in some locations. The showings appear as disseminations along the faults. To date, the work has been mostly geologic mapping - 1 to 50,000 with details on a scale of 1 to 20,000 and 1 to 10,000-stream and soil lithogeochemistry, and geophysics. Trenching and sampling were used to follow possible vein extensions. Particular emphasis has been placed on the Los Candelones district that was taken over by Rosario Dominicana. Here is where drilling has been initiated in the past months. The first hole drilled showed assays of 21 g/t (0.6 oz per st). The second hole intersected an interesting oxidized zone that reminded observers of the original Pueblo Viejo oxidized zone. A third drill hole went deeper than 75 m (246 ft), the depth to which the first two holes had been scheduled. An assay of 50 g/t (1.46 oz per st) was cut during drilling. The presence of an oxidized zone of any vertical and horizontal extent is important. This gives rise to continued exploration, as the

Jan 2, 1986

By R. V. Ramani

This paper is based on the thesis that the demand for computer-oriented mining engineers will continue to sharply increase in coming years. It presents the philosophy behind the development of a mine systems engineering program at The Pennsylvania State University. The paper discusses the current status of mining engineering education and the problems encountered in integrating extensive computer background and education into a traditional mining engineering program. The paper analyzes the interrelated roles of research, graduate studies, and continuing education in developing a comprehensive program of study. It is hoped that this program philosophy will be useful to other institutions which are contemplating new programs and courses in emerging technologies.

Jan 1, 1982

By F. Michael Wahl

With the exception of reports on commercial deposits of kaolin, fuller's earth, and other specialty type clays, there is little published information on the extent, properties, and potential uses of the clay resources of Florida. Recent studies by the Florida Bureau of Geology in cooperation with the University of Florida and the U.S. Bureau of Mines have proven the existence of two extensive Miocene clay deposits, one in peninsular Pinellas County and the other in southeastern Charlotte County. Drilling and subsequent testing of the clays from these deposits indicate their potential for economic development. Both deposits consist of montmorillonite type clays, have an average thickness of 25 to 35 feet, and are overlain by unconsolidated Pleistocene sediments. Preliminary firing tests indicate that the clays from Pinellas County are a potential raw material for lightweight aggregate production. The clay has good bloating characteristics across an acceptable temperature range with a resultant aggregate density of less than 1.00 specific gravity. The clays from Charlotte County have poorer natural bloating characteristics but might well be used after treatment or with additives. The economic potential and locations of both deposits emphasize the need for locating similar clay resources in the state that might have economic potential so that land use planning and subsequent urbanization will not prohibit their development.

Jan 1, 1972

By M. Jawed

Coking coal reserves in India are distributed geographically in Giridih, Raniganj, East Bokaro & Jharia Coalfields (J.C.F.). 97% of prime coking coal in JCF coming through underground mines is credited to Bord & Pillar mining systems inspite of the fact that it results in heavy mining losses. The cost of mining in B & P mines has been much higher due to various factors. In this paper, O.R. model has been discussed with case study for optimizing the cost of production in operational underground mines. Also, a computer algorithm has been discussed using a schematic flowchart, which provides the trend of mining-losses 'in different mining, systems with changing design parameters and finally selects, the optimum mining system for undeveloped seams based on economic appraisal criteria.

Jan 1, 1989

By L. Wade, D. R. Pearce

A detailed account is given of the spectral ratio laboratory method for the determination of seismic velocity and attenuation through rock cores under simulated in-situ stress conditions. An account of a computer program called AUTOQ is described for automatic processing of a complete set of laboratory results. Some of these results are shown and discussion is directed to- wards the suitability of in-situ velocity or attenuation measurements in determining rockmass condition or stress regime.

Jan 1, 1996

By Vanessa M. Torres, Lafayette C. L. Freitas, Evandeo C. Silva

This paper shows two applications of artificial intelligence models in process development. In the first application, a heuristic fuzzy correlation can predict flotation behavior in bench scale based on feed characteristics for a high variability copper ore, as well as to predict plant performance for a feasibility project evaluation, minimizing its risk. The second case study shows the use of neural networks to model the iron ore sintering, correlating ore characteristics and operational parameters with sinter properties. With this application, CVRD aims to establish a new step on iron ore product evaluation and customer support.

Jan 1, 1998

By Z. Kowalski

Landfilling of waste causes the degradation of natural environment, not only due to land occupation, but also due to pollution of air, water and soil. The flotation waste from zinc-lead industry also poses such problem. There is a need to find the way to utilise substantial amount of these wastes and backfilling seems to be a good solution. Recently, in Poland only sand was used for backfilling. However, it will be more beneficial to substitute the sand with the industrial solid waste, especially flotation waste. The tests were performed in the laboratory to examine the use of flotation waste as a main ingredient for backfilling. The use of flotation waste is possible only when it is combined with other waste with specific bonding properties, especially regarding the prevention of leakage. The outcome of tests shows that flotation waste combined with cement and fly ashes can be used as a backfilling material. This paper presents the preparation of flotation waste for using it for backfilling.

Jan 1, 2006

By Steven G. Vick

Not too long ago a mill superintendent, when asked where his tailings were being disposed, could simply shrug his shoulders and point to the open end of the thickener discharge pipe. This “out of sight, out of mind” approach to tailings disposal is a practice of the past. Today there are very few planned hardrock or energy-related mining facilities where tailings disposal has not been identified as the major area of impact and controversy. In fact, development of some ore bodies has been stymied altogether by lack of suitable sites or methods for tailings disposal. The bottom- Iine result is that tailings disposal often controls the permitting lead time and has a significant influence on construction cost (up to 2070 in some cases) of new minemill complexes. The following article, the first in a series of three, explores technical background and historical perspectives on siting and design of tailings impoundment facilities.

Jan 6, 1981

By Alden B. Carpenter

The Dead Sea is the only relatively large body of surface water having bromide concentrations comparable to those in the brines of the Smackover Formation in Arkansas. The Dead Sea, like the Smackover brines, contains a great deal of calcium and is very low in sulfate and iodide. The relationships between potassium, divalent cations, and chloride indicate that over 20 percent of the bromide in the Dead Sea is derived from some source other than by the evaporation of sea water. A similar type of study of the Smackover brines in Arkansas indicates that approximately 60 percent of the bromide has been derived from some source other than sea water. Both the Dead Sea and Smackover brines are very low in iodide suggesting that the excess bromide has not been derived from organic matter. The origin of the excess bromide is probably the same for both of these brines, but the source of this bromide remains unknown.

Jan 1, 1978

By F. H. Muge

The problem of how to handle heterogeneous populations in an ore reserve global estimation arises in many geostatistical studies. In some cases it is possible to split data into different significant types of ore in such way that non-overlapping subpopulations are obtained, and a separate study is possible. In other cases the subpopulations are intermingled and a set of nested structures may model the spatial variability of the ore. Finally, one of the populations, consisting of a small proportion of high grade values of economical meaning, may disturb the structural analysis. In this paper, some methods are proposed to cope with these kind of problems and typical case studies are presented.

Jan 1, 1986

By James L. Vanderbeek

The Chino concentrator commenced operation in 1982 as a SAG-ball mill circuit which could process 37,500 stpd of ore. Since 1982, a series of process improvements such as the addition of two stages of SAG recycle crushing, allowed throughputs to increase to more than 48,000 stpd, at the expense of significantly coarser flotation feed sizing and reduced recovery. To compensate a third (tertiary) stage of grinding consisting of four 1250 hp Vertimills was installed which has allowed the flotation feed size and recovery to return to historical levels. The design and operational characteristics of the Tertiary Grinding Circuit are described.

Jan 1, 1998

By Boris K. Krstev

INTRODUCTION The flotation process, in the real industrial complexes, is characterized by the existence of the significant number of the close reciprocal interrelationship between the input and output Darameters. Traditional complexity is appeared with regard to absence of the suitable a priori information for the physico-chemical characteristics of the flotation process. It’s led to needful of taking of consideration about the undefinition which have got the place in the real conditions and application of the statistical methods. The identification of the flotation process through statistical methods is conception of the more-stages procedure, including the collection and previous analysis, the choice of the model structure and valuation method, the estimation of the model un- known parameters and the results interpretation. The essential concept for the subject of this paper belongs to the empirical models ("black-box") and deals with optimizing in constant industrial plant process. The offered method envisages the application of process operation data in order to improve the work process or constant accomplishment of better results for the target function in relation to the former achievement. The optimum process solution isn't afixed value under the influence of various factors, but "a moving point" along the response surface and deviates from the scheme solutions. The evolutive planning method constantly "investigates and approaches" the optimum solution for the selected target function. As a matter of fact the expert operates the plant without interrupting the normal work process. The essential concept of method is to attain changes in the standard conditions, but so limited that they will not effect either production or the product. This method is based on statistical concepts and availability of following the risk of error. The possible influental factors for the flotation process (m=l, 2, 3) is following: the metal content in the feed ore; production level (t/h); grinding fineness in the flotation pulp; pH-values; the consumption of collectors and modifiers The possible target functions are: the recovery of plant capacity, metal recovery in the concentration process and concentration quality. The application of the evolutive operativity method in the chalcopyrite flotation- Bucim concentrator, combines the statistical data and the operator's experience in the interpretation and making a decision which adds up to the precise automatic performance of the process. The advantages of this method in relation to the existing procedure for the flotation process are the following: • The method is unexpensive and losses are reduced to the time necessary to collect the data and record them in the computer. This method provides a constant process control and a quality decision which is better than those brought by an ex- pert with great experience ("hit-and-miss method"). • The method also provides incidental data about the effects. • The method should not be considered as a procedure for solving an incidental problem ("crash program"). • The obtained results must be interpreted by an appropriate expert in order to be considered instructive. MATHEMATICAL STATISTICS Taking into consideration the complexity of the enrichment processes it's necessary the application of "black-box" and mathematical modelling. The presence of the indefinite elements compel us towards the both theory of the probability and mathematical statistics. The mathematical statistics by the mineral processing investigation of the valuable raw materials in the last years has had greater signifance and widely spread application. The application of the mathematical statistics methods for the technological pro- cess analysis and the construction of the mathematical models is bound up by the task putting of the automatic control system de- sign (Fisher R. A. 1941, 1949). The statistical analysis in the enrichment processes is applied formerly, especially in the sampling estimation. Contemporary, in the last years is imposed the tendency of mathematical statistics application for the obtaining of quantity characteristics and quantity valuation from the individual influental factors. Above mentioned tendency in the significant level is based by the mathematical statistics development as a mathematical discipline close connected with the technical cybernetics general joining to the investigated object as a "black-box". Another essential factor in the mathematical statistics development is appeared the created mathematical theory of experiments as a new, to some extent, autonomous statistical domain. The theory of experiments has demonstrated exclusively importance for the investigation of the complex more-factorial processes in the chemistry, mineral processing, metallurgy etc. The investigation by the enrichment processes of the valuable raw materials and their management is possible by the statistical method application. In the same time, it's possible to use the wide-spread traditional methods of the statistical analysis, such as the methods of the dispersion, correlation, regression etc. Also, it may be mentioned above all the methods of the statistical planning of the extreme experiments. The more perspective are representatived some cybernetic methods which are based by the probability as an approach in the process analysis, for example, the identify of the ways and forms, the graph application as an additional instrument in the correlation analysis, the dynamic programming etc. The mathematical statistics application in the laboratory investigation scale is connected above all by the experimented material analysis and the compact representation of the obtained results. The mathematical statistics methods are more varrying and may be applied in the investigations of the wide circle of problems

Jan 1, 1996

By Chen Ziming, A. Burkert, A. L. Mular

A mechanism has been proposed for autogenous grinding that involves three distinct types of breakage: self impact breakage, media breakage and abrasion. Based on this analysis a mathematical model and an autogenous grinding simulator have been developed. Using pilot plant data fitted to the model, the simulator was tested and employed to examine both the scale-up problem and the effect of feed size distribution on performance.

Jan 1, 1995

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

The mining industry has indeed gone global. International minerals producers are spending big money to move into countries that were off limits a few years ago. Due mostly to political reasons, these countries' huge mineral deposits - worth billions of dollars - were locked up and mining companies could only sit on the side and wonder "what if." Now much of the world is going the free market route. Once closed countries and developing nations are rewriting their mining and tax laws hoping to attract foreign investment to develop their natural resources. And big businesses - mining companies included - are lining up to get their share. But with new opportunities come new risks. While emerging nations are slowly accepting the free market concept and the privatization that goes along with it, many remain plagued with political instability and violence. Even developed nations carry their unique risks. Some of these include inadequate or contradictory legal and regulatory infrastructures, political patronage and outright corruption. So companies hoping to expand into new regions of the world must do more than examine the market. They must study the political stability and structure of a country, as well as its tax and environmental laws. And they must guarantee the safety of their employees. Control Risks Group is an international management consulting company that assists companies preparing to move into a new country. It employs about 225 people in 14 offices throughout the world. Control Risks personnel include lawyers, bankers and former law enforcement officers and intelligence people. The company held a one-day seminar in Washington, DC to update some of its clients on the state of affairs in various regions of the world. The seminar also covered extortion, corruption and product diversion. About 175 people attended the seminar. Speakers included Control Risks' operators, analysts and investigators. Here is a summary of what some of those people had to say.

Jan 1, 1998

By Matias Pentinnen, Wayne Dickinson

Electrowinning is a key process for copper production contributing roughly twenty percent globally and thirty to forty percent of production in the Americas1. Copper grade is assessed largely on deposit smoothness and on level of impurities in the metal. Smoothing aids are essential to create dense, low porosity deposits and guar has long been the material of choice for this purpose. Guar is, however, poorly stable under the strongly acidic electrowinning conditions, underlying ongoing research to identify an effective, acid-tolerant replacement. Current efficiency is also a critical factor in controlling copper production costs and chemical additives should ideally improve current efficiency as well as improving deposit smoothness.

Feb 1, 2025