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By D. J. Dollhopf

An overburden handling dragline operation was conducted at a strip mine near Colstrip, Montana. The objective of the demonstration was to determine the degree a dragline could mix overburden inhibitory zones during the spoiling process. In order to quantify the mixing process the overburden was: 1) scatter spoiled; 2) dump spoiled; and 3) spoiled in a normal manner. This demonstration was part of an effort to investigate means of reestablishing non-polluted hydrological systems in areas where surface mining directly impacts shallow ground-water resources. When inhibitory material constituted < 5% of the total overburden volume, such material was essentially not detectable in the resultant spoil pile. When inhibitory material exceeded 15% of the overburden volume it was always found in the resultant spoil pile, generally with a smaller extent, indicating partial dilution. Inhibitory overburden zones often reappeared at the base or top of spoil piles in the potential aquifer and root zones suggesting the need for selective placement procedures. Scatter spoiling did not appear to be significantly more effective than normal spoiling, however clump spoiling seemed to produce less mixing of inimical zones. Mining activity has reduced ground-water levels within 1600 m of the active pit. The aquifer which is developing in spoils appears to have similar confinement characteristics as those that existed in the premined aquifer. To date no definite trends have been observed concerning changes in surface or ground-water chemistry associated with mining.

Jan 1, 1978

By G. Avolio, M. Gilbert

INTRODUCTION The city of Alexandria, Egypt is located on the Mediterranean Sea at the northwestern edge of the Nile River delta. The city is approximately 26 km long and 3 km wide bounded by the sea to the north and Lake Maryut to the south. The Alexandria Project is split into 2 phases: phase one included designs to update two existing primary wastewater treatment plants, five pump stations and over 75 km of sewer pipe, 18 km o f which is tunneled, (1500mm to 2750mm ID pipe). Currently the pipeline and pump stations are under construction. Phase two of the project includes expanding both the capacity of the treatment plants and the limits of the collection system. Included in this system expansion is the 3.5 km long, 2250mm ID Central Zone Conveyance, which is the subject of this paper. The project is under the direction of The Alexandria General Organization for Sanitary Drainage (AGOSD). It is an USAID funded joint venture of two American firms, CH2M - Hill and Metcalf & Eddy who share equally the major portion of the work and two Egyptian firms, Engineering Consultants Group (ECG) and Wairth Associates who are also partners. The venture, which is both design and construction management, worked under the name Wastewater Consultants Group, WWCG. Michael Gilbert was Chief o f the Geotechnical Department and Project Engineer for the Central Zone Conveyance. Gennaro Avolio was Geotechnical Exploration Manager for the Alexandria Wastewater Project.

Jan 1, 1987

By Orlando Bernal

El presente texto aborda el aspecto termodinámico del sistema de lixiviación -en tanto predice los fenómenos que ocurren en el interior de la pila para luego continuar con el análisis del mecanismo cinético. La metodología aplicada en cuanto a los mecanismos de lixiviación, difiere de otros trabajos porque aquí se considera los tres mecanismos por separado (óxidos, sulfuros secundarios y primarios) basados en el análisis secuencial del cobre. Asímismo la cinética per se obedece las leyes de la termodinámica ergo, cuyo aspecto no puede ser ignorado en un análisis global. En este sentido, se presenta el modelo de desarrollo matemático como una herramienta óptima que controla y predice este proceso del lixiviación por medio de la simulación utilizando la ecuación de continuidad, la cual supone flujo tipo pistón de la fase líquida en el interior de la pila.

Sep 9, 2007

By R. G. K. Morrison

As mines grow deeper, the problem of ground control becomes one of increasing importance. The literature on the subject has grown extensively in the past few years, but is still far from conclusive. Detailed and precise observations are on record covering most phases of the problem, and control measures have progressed to the point where, in a large measure, they are effective. The success of methods to date must be attributed to the efforts which have been exerted to reduce convergence of stope walls and to the realization that a regular progression of stope faces approaching longwall has a beneficial effect. This paper attempts to explain the relationship between these two factors and the general problem of ground control. The problem at present lacks the co-ordination of the practical with the scientific outlook, but fortunately as time goes on there are indications that our scientific friends are becoming more interested and more familiar with the practical issues involved. Opinions vary widely regarding the mechanism of the problem and there are several schools of thought, two only of which will be discussed. One associates the incidence of rock-bursts with the stresses built up by a sagging hanging-wall, while the other takes the view that stresses primarily responsible for the sagging hanging-wall are also the cause of rock-bursts. The first group starts its reasoning from the convergence of the walls, probably the most conspicuous feature of deep mining, and works back to the conclusion that rock-bursts are in sorne way due to the breaking up of the sagging layers. The second group begins with the stress zone apparent around excavations at depth and follows mathematical conceptions based on certain assumptions which, in the absolute sense, are known to be inaccurate, but which are justified by the similarity between the conclusions reached and the results obtained in practice. This reasoning is followed to the point where rock-bursts result from the failure, under stress, of rock in situ, quite independent of wall convergence.

Jan 1, 1939

By Clinton C. Knox

Attention of mine operators and engineers in the Picher zinc-lead field has been drawn increasingly in recent years to marginal ore deposits lying at greater than normal depth below surface in the marked structural depressions known as the Miami and Bendelari troughs. Not only mining but prospect and development drilling is relatively costly in the bottoms of the structural depressions known as the. Miami and Bendelari troughs which cross the center of the Picher field. Nevertheless, operations by various mining companies in recent years have shown that no insuperable problems exist, and with the gradual lowering of grade cut-offs throughout the field, certain potential deep-ore areas, previously only partly explored seemed worthy of further investigation. Some such areas were called to the attention of Bureau of Mines engineers by lease holders and operators, while others were noted in the course of Bureau&apos;s systematic investigation of Tri-State ore reserves. The writer was assigned to make a study of. those possible "trough extensions," in the course of which all available nine maps, drill logs, and prior reports were assembled. Subsequently 41 churn drill holes were bored by the Bureau in the periods October 1944 to May 1945 and October 1946 to April 1947. The general area under investigation this project is indicated on figure 1, which likewise shows its relation to nearby towns, roads, and railroads. The location of individual deposits included in the report is indicated more clearly on figure 3. Minable ore was found in only two holes, and the structural information procured by drilling was less encouraging than anticipated. This report, however, presents all factual data obtained, in the belief that they may be useful in subsequent prospecting and development projects in the areas investigated. There are also set forth some of the stratigraphic data relative to the Picher field ns a whole and the Miami and Bendelari troughs which were assembled in the preliminary investigation of this project.

Jan 1, 1949

By Patrick M. - Langevin

THIS TALK IS ABOUT : How the DBL mining camp deposits have been found and what is done to find the next one PLAN: Overview of the geological context Historical exploration perspective Deposits geology and key features Conclusion

May 1, 2006

By Kenneth H. Johnston

The Weber pool in Washington County, Okla. (fig. 1), covers an area extending from 2 miles east and slightly north of Bartlesville, Okla., to a point approximately 2-1P tiles northeast of Dewey, Okla. The pool is a part of the area designated by the Standing Committee on Oil Field Nomenclature, Kansas-Oklahoma Division, Mid-Continent Oil & Gas Association, as the Bartlesville-Dewey field. In the following discussion of the geology, development, and exploitation of the Weber pool, the writers, by means of structure maps, cross sections through various parts of the reservoir, and tabulated development data and production statistics, have recorded salient information on a field that was developed before .1910 in an Area that has been repressured since 1926. The total oil production to January 1, 19.0., from the 2,639 developed acres considered in this report, was approximately 14 million barrels, or a recovery of about 5,3;2 barrels per acre, or 227 barrels per acre-foot. The production of the estimated 18 million barrels of recoverable oil remaining in the Bartlesville sand reservoir will require the initiation of additional secondary-recovery practices on some of the leases and the application of a more systematic repressuring program on others.

Jan 1, 1950

By Wayne A. Charlie

An experimental test program being conducted at Colorado State University and involves the study of the behavior of water saturated sands under shock and explosive loadings. The study is being conducted to evaluate potential blast induced changes in dynamic soil properties, soil shear strength loss (liquefaction) and densification of water saturated sands under single and multishock loadings. This paper presents testing and measurement objectives, and the equipment and instrumentation developed to load, measure, record and analyze the transient and long term soil behavior. The laboratory shock facility is capable of generating multi-shock pulses with milli-second rise time, peak stress amplitudes of up to 35,000 KPa (5000 psi), peak particle velocity of 5000 cm/set and peak acceleration of 10,000 g. The field explosive facility subjects saturated soil to controlled explosive loadings. Of major interest is the soil strain and water pressure, both during and after the passage of the stress wave, as a function of peak particle velocity, peak strain, loading rate, soil density, initial confining stress and the number of loadings. Based on data obtained to date, soil densification is due to consolidation following liquefaction.

Jan 1, 1991

By Esher Hsu

In Taiwan, around 8,000 tons of batteries are consumed per year but only 17% of which were collected and transported to oversea for recovery. The dumping used batteries have become a potential environment problem. How to increase the collection efficiency of used batteries is an important issue for EPA in Taiwan. Besides, some treatment plants are on process to get permission for recovering used batteries. The objective of this study is to estimate the recycling cost of spent consumer battery and explore the feasibility of recovering used consumer batteries in Taiwan based upon the principle of cost-efficiency. The recycling cost including collection cost and recovery is estimated based on a survey. Results would provide some suggestions to Taiwan EPA regarding feasibility of recovering used batteries in Taiwan.

Jan 1, 2006

By Peter Cain

The paper presents previously unpublished results derived from an unique interaction moitoring program conducted in the Sydney Coalfield of Nova Scotia. An abandoned, sealed longwall gateroad was re-entered and instrumented prior to extracting a longwall face 140 m below it. Instrumentation included piezometers connected to a constant head tank to monitor subsidence, and horizontally mounted extensometers to measure strains associated with subsidence. Survey levelling data was also collected. The monitoring results have allowed a number of significant conclusions to be drawn, all of which were either unanticipated or contradict current mainstream thinking. Firstly, interaction subsidence was less than anticipated. Secondly, the effects of rate of face advance on the development of the subsidence profile are evident. Thirdly, compressive strains are shown to remain in the subsided strata. Finally, strata response to undermining was almost immediate. The impact of these findings on the extraction of longwall panels beneath flooded workings in the Sydney Coalfield are discussed.

Jan 1, 1996

The Bibliographic Data Base is the result of a literature search con-ducted as one task of the technology assessment of current and advanced logging techniques, sponsored by the United States Bureau of Mines. After compilation, the bibliography was converted to an automated form for ease of utilization, and to allow for maintaining and updating the data base. The data base covers articles, symposia, books, patents, corporate and government reports, and other literature concerned with some aspect of borehole logging from January 1969 through December 1975. Periodic up-dating will be necessary to keep the data base contents in step with developments in the rapidly advancing field of application of borehole logging to mining. Many bibliographic indexes were scanned for entries relating to the subject of interest, and those entries which were included in our data base contain a reference to the bibliographic index in which they were listed (see Section 2.4.7). With the aid of these indexes, a vast number of publications, including foreign reports and publications, have been scanned for works relevant to borehole logging technology.

Jan 1, 1976

By Ralph P. Hackl

Ore at the Congress gold property, located near Goldbridge, British Columbia, is extremely refractory with most of the gold disseminated in fine-grained arsenopyrite. Metallurgical testwork conducted by Giant Bay Biotech Inc. indicated that biooxidation pretreatment was capable of increasing cyanide gold recovery from the ore to greater than 90%. To determine if the bioleach process could be successfully scaled up, a 225m&apos; (7950-cu ft) commercial size bioleach reactor was built and tested at the mine site in 1989. At that time, the tank was the largest bioleach reactor ever operated. The objectives of the program were: • to ascertain if the biooxidation rates obtained in lab and pilot-scale reactors could be duplicated in a commercial scale tank; • to identify agitation conditions under which the process will function optimally; and • to demonstrate the bioleach process on a scale sufficient to satisfy the owners and potential investors.

Jan 1, 1990

By Rob Thomas

Strata management is a critical and now necessary requirement in the New South Wales underground coal mining industry. As a formal and structured process, strata management allows ground support and mining methods to be tailored to the anticipated and encountered geotechnical environment in a controlled manner. In its application, strata management therefore enables operators to identify and control geotechnical hazards and the risks they pose to the mining operation, including risks to personnel safety and mine production. The paper considers recent developments in strata management in the New South Wales underground coal mining industry. Points covered include the statutory requirements stipulated in the Coal Mine Health and Safety Regulations, Geotechnical Hazard Plans, tiered support plans, the Authority to Mine concept, Trigger Action Response Plans and monitoring. Several successful and unsuccessful case studies are included which make specific reference to roadway development and longwall retreat and in doing so, the unique demands imposed by these two different aspects of the mining operation on strata management.

Jan 1, 2007

By K. T. Lee, M. U. Ozbay, M. D. G. Salamon

Design of yielding chain pillars in deep coal longwall mines is not as well established due mainly to the lack of knowledge in the behavior of coal pillars in the post-peak regime. This study shows that two of the existing strain-softening models have the potential to provide an improved understanding of yielding and, therefore, could form a rational basis for yielding coal pillar design. Analytic and numerical modelings of a row of chain pillars in a two-entry development at a depth of nearly 700 m suggests that yielding pillars are feasible, but the design is very sensitive to the coal’s post-peak behavior.

Jan 1, 2001

Keywords: Pyrometallurgy, Wits University, research Wits Metallurgy celebrated its centenary in 2004. The department has been at the forefront of education and research and has contributed greatly to the metals and minerals industry, both in South Africa and abroad, in terms of human resources and knowledge generation. A significant number of industry and academic leaders worldwide are Wits Metallurgy graduates. Since its early beginnings, pyrometallurgy has always been part of the curricula and research offered by the department. Pyrometallurgical activities started to expand tremendously from the middle of the 1960s, especially by the formation - together with Mintek - of the Pyrometallurgy Research Group, which continues its internationally recognised research activities today. The research efforts have been concentrated on problems associated particularly with ferroalloy, steel, stainless steel production, and PGM/Cu-Ni sulphide smelting. In recent years, research has been further expanded to physical modelling of pyrometallurgical reactors. Almost all of the specific research projects were handled from a fundamental point of view, and hence a large number of MSc(Eng) and PhD degrees were achieved by candidates under the supervision of the Pyrometallurgy Research Leaders. Moreover, a significant portion of the research results were published in internationally recognized journals and conference proceedings. Among these, Infacon and the Molten Slags, Fluxes and Salts Conference series are worth mentioning. The studies from a fundamental point of view include thermodynamics, phase equilibria, transport phenomena, kinetics, and process dynamic aspects of high temperature processes and systems, both in the solid and liquid states.

Jan 1, 2006

By J. H. Adkins

The purpose of this research is to identify hazards associated with roof bolting and to make recommendations for procedural and equipment design changes to reduce those hazards. To that end, the project reviewed Literature on related research, collected and analyzed roof bolting injury data, normalized the injury data be exposure time to each activity and identified problem areas within the root bolting tasks. In addition, field data collection forms were prepared and mines selected for field work. In the field, observations were made of eighty (80) different roof bolting crews bolting one hundred fifty-five (155) place;, on forty (40) sections spread among nine (9) mines. Task analysis forms were used to record unsafe behavior or conditions for each crew and each place. Informal discussions were held with the mine&apos;s safety and training officer, the maintenance officer, one section foremen and, when possible, the observed crew, concerning the training and experience of the miners. Unsafe acts were categorized and related to the "Activity While Injured" categories developed during the accident analysis. For each of these categories one or more recommendations for corrective measure, machine modification, procedural change or job training were developed. The study produced over fifty (50) specific recommendations involving machine design, procedural, safety training and supervisional issues that would lead to reduced roof bolter injuries in the near term. The authors concluded, however, that only the development of truly hands off/remote bolting can eliminate or reduce to an absolute minimum the hazards to which the roof bolter is subjected.

Jan 1, 1977

By Diane Jones, Jeremy Spearman, Tom Matthewson

Requirements for minerals are on the increase globally and the deep sea offers a potential source of essential materials. Extracting these minerals from what is considered an environmentally sensitive area, and one about which little is still known, is a challenging activity, which needs careful consideration and an appropriate environmental impact assessment to be carried out. Extraction of material from the deep sea beds can cause disturbance or damage to benthic communities; impact on mobile marine species such as fish, mammals and reptiles; cause increases in suspended sediment and sediment deposition onto potentially sensitive areas or potentially release contaminants which were previously bound to the sediment. This paper discusses the potential environmental issues surrounding extraction of deep-sea deposits using aggregate dredging techniques and how those issues can be appropriately assessed. In particular issues of suspended sediments, plume transport, water and sediment quality and underwater noise impacts on potentially sensitive species and habitats will be explored.

Sep 1, 2014

By Marreros D. Oscar

La perforación y la voladura son mecanismos que suministran material adecuadamente roto al equipo de carguío. La efectividad de ambos depende de la evaluación de la perforadora y de los explosivos a utilizar. En esta perspectiva, el presente trabajo describe los parámetros necesarios para evaluar los requerimientos de perforadoras en una mina nueva. El proceso de selección y evaluación conlleva una optimización económica del equipo de perforación para cumplir el plan de minado, asegurando la producción t reduciendo los riesgos financieros. Asimismo, se presenta el análisis de inversión con la técnica de flujo de caja descontado.

Aug 26, 1988

By Ian R. Firth

For the majority of open pit precious metal mines in the western United States, grade control practices have evolved as a direct result of the variable geology of the ore body and the lack of a clear visual or geologic distinction between ore and waste material. These practices often include the extensive use of buffer or choke blasting, in an attempt to minimize lateral movement of the muckpile. The Mackay School of Mines is conducting ongoing research, which aims to develop a practical method of measuring the movement of discrete “targets” placed within the body of the blast. The movement experienced by these targets can then be used to interpolate the movement of the blast as a whole. Typically, the boundaries between different material types are known as digging limits or polygons and are marked using colored flagging on the muckpile. If material movement can be measured using targets placed in the blast, these digging limits can be altered to reflect the blast-induced rock movement, reducing dilution and improving value recovery.

Jan 1, 2002

By Peter Cain

In response to the appearance of excessive convergence of bolted gateroads in the front abutment zone of retreating coal faces at Phalen Colliery, staff from the CANMET Cape Breton Coal Research Laboratory in Sydney, N.S. initiated a programme of roof profile measurements in the front abutment zone of longwall headgates. The results of these measurements allowed a characteristic deformation curve to be determined for each headgate, and the early identification of areas showing an unstable deformation trend. These areas were then reinforced with supplementary support. The monitoring programme was adopted and enlarged by the rock mechanics staff of the Cape Breton Development Corporation, and has been continuing for a period of approximately two years. A sufficient quantity of data now exists to be able to make an assessment of the effects of a number of mining parameters on the performance of the gateroad in the front abutment zone. The following paper describes the method of measurement, illustrated by typical results, and goes on to relate variations in rate and patterns of movement to geology, interaction, method of support and pre-mining stresses.

Jan 1, 1996