Search Documents

By Giannini M

Of the optimization techniques proposed in determining the optimum open pit limits, dynamic programming and graph theory have proved most successful. However, publications on these two methods lack a certain amount of rigour and clarity in exposition. Certain ideas in the methods have been clarified and additional features introduced in order to make them more sensitive to practical applications. A case study in the form of an application of these ideas on data from a producing mine is presented and discussed.

Jan 1, 1986

[ ]

Jan 1, 1997

By Bengt H. Fellenius

The design of pile foundations is much more commonly verified by means of a full-scale test, than is the design of other foundation units. The reason is not that our knowledge of pile behavior is more uncertain than our knowledge of other foundation types making the verification necessary, but more that the loads in a structure are more concentrated to single foundations in a structure founded on piles as opposed to structures on footings or mats. Therefore, should a pile cap fail or move, the adverse consequence of this is often drastic, as the piled structure has little freedom to transfer its need for support to other foundation units. Consequently, it becomes important to assure the design of piled foundations. In many, maybe in most instances, the static pile loading test is routine and geared toward determining an at least capacity, only. However, in these times there is an ever increasing liability of the professional, demands for increased economy of the foundation, and frequent lack of the involvement in the test of the experienced old-timer exercising good judgment. Furthermore, modern pile design is leaving the single, simple concept of capacity and requires more information from the test to assist in determining aspects of long-term behavior and settlement. Therefore, even the straight forward, routine static loading test requires improved planning, execution, and analysis.

Jan 1, 1990

By Jacob Petersen, Jon J. Kellar, Samuel Kessinger, Kiran Green

Belle Fourche Shale was processed and characterized for use as a clay-based ceramic. The shale was wet sieved to produce particles that were ± 150 μm. X-ray diffraction (XRD) revealed that the -150 μm material was enriched in clay content compared to the unprocessed materials, whereas the oversize material was enriched in quartz compared to the undersize sample. Particle size analysis was performed on the—150 μm sample, which showed that the median particle size was around 10 μm. Scanning electron microscopic (SEM) analysis further confirmed the small plate size, which appeared to be primarily layered clay particles. Next, the -150 μm particles were rolled into a green body, dried at room temperature, and fired at 998°C. The fired piece was analyzed by XRD and contained 6 wt% hematite, 55% quartz, 19% microcline, and various other minor amounts of minerals. When fired at 1152 ℃, mullite was found with increasing hematite compared to the 998 ℃ firing. A multi-spectral analyzer was used to quantify the color change of the 998 ℃ fired (orange) to the 1152 ℃ fired (red) samples. Micro-computed tomography (Micro-CT) of the unfired body exhibited very few large pores, while the piece fired at 998°C also exhibited few and small pores, the overall porosity of the fired body increased. Microhardness data, obtained from the aforementioned samples, resulted in Vickers Hardness (HV1.0) values of 70.8 HV1.0 (998 ℃) and 485.7 HV1.0 (1152 ℃). Three-point bend testing was performed, giving an average strength of 23 MPa on pieces fired at 998 ℃. The average bending strength of the samples fired at 1152 ℃, was 55 MPa.

Sep 26, 2023

By H. Boghosian

This paper presents the design and construction of a deep basement in a steeply sloping site in glacial till in Glasgow city centre. Existing foundations, adjacent structures and services, in tandem with asymmetric loading, presented particular challenges in the planning, execution and design of the project. The construction methods and temporary works, analysis by the Finite Element method and monitoring carried out are all described.

Jan 1, 2006

Thomas Haight Leggett, London, Eng. (communication to the Secretary): Mr. Hammond has given us a concise yet complete description of the Witwatersrand gold-fields, and the character of the operations which have resulted in their remarkable development.

Jan 1, 1902

Editor?s note: Each year, Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue, all the while doing their own jobs. Thank you to the industrial minerals annual review editor, to the Industrial Minerals and Aggregates Division technical committee chair and vice-chairs, and to the authors of the individual commodity profiles. Jim Norman, member SME, of Tetra Tech, is the industrial minerals annual review editor. Rajesh Raitani, member SME, of Cytec Industries Inc., is chair of the Industrial Minerals and Aggregates Division?s Technical Committee. The technical Committee vice chairs include: ? Vishal Gupta, member SME, of FlSmidth, Agricultural Materials. ? Candace Trimble, member SME, of Oil- Dri Corporation of America, and Bradley Van Gosen, of the U.S. Geological Survey, ceramics and refractory materials. ? Stanley Krukowski, member SME, of the Oklahoma Geological Survey, chemical raw materials. ? Russell Winn, member SME, of R.E. James Gravel Co., chemical raw materials. ? Justin Zdunczyk, member SME, of Plum Creek, construction materials. ? Jerry Gauntt, member SME, of Golder Associates, fillers and pigments. ? Michael Cheshire, member SME, of Los Alamos National Laboratory, sorbents, filters and process aids. ? Rajesh Raitani, member SME, of Cytec, Industries Inc., specialty minerals. Their help makes possible this June industrial minerals issue. On behalf of ME readers, the editors thank them.

Jul 1, 2013

The introduction of cement into underground backfilling at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited mines to improve mining efficiencies gave rise to several major problems, the magnitude of which had not been anticipated. These problems were 1. A loss of recovery in the milling circuit due to the presence of cement 2. The presence of cement-rich slime layers on the surface of the fills 3. The introduction of a safety hazard due to the slippery nature of the surface of cemented fills 4. The deposition of cemented slimes on the levels and in underground sumps and dams. The loss of revenue due to decreased metal recoveries considerably offset the gains from increased stoping efficiencies and the use of cement was substantially reduced while, (a) the Metallurgical. Department attempted to identify the chemical nature of the problem and overcome it, and (b) the Mining Department investigated methods of reducing cement contamination of the ore stream. As a part of this investigation the Mining Department added polymeric flocculants to the cemented fill pulp. Testwork was carried out in the following steps 1. The available Alfloc polymers were screened to determine which was the most effective and what was its optimum dosage rate. 2. This polymer was used in the laboratory to determine the reduction of surface slime, clarity of water, and effects on strength and percolation of fill. 3. Fills were placed underground to substan- tiate the laboratory work. /+. The polymer was then added to all cemented fills going underground to study its effect over a long term. The use of flocculants not only improved the distribution of cement in the body of the fill, but also the distribution of the fines fraction of the filling material, practically eliminated slippery surfaces and improved the clarity of the drainage water. Flocculant is now added to all cemented fills and restrictions on the use of cement are gradually being lifted.

Jan 1, 1973

By E. Haug, Quamrul Ahsan, R. Norcross

Cyanide leaching is the most common process employed in the majority of the gold extraction plants. These gold extraction plants naturally generate tailings and/or effluents that contain highly toxic cyanides, In geographic locations with excess precipitation and therefore net positive water balance, a portion of these tailings must be discharged. Before these highly toxic cyanide-containing effluents can be discharged to the waterways, cyanide and any other toxic substance must be destroyed. Geographic locations with high evaporation and low precipitation, as in the western USA, result in net negative water balance and therefore these plants can operate with a zero discharge option. However, with the current stringent environ­mental regulations and concerns for bird and wildlife mortality, even these operations may be required to partially treat their tailings to preclude potential harm to wildlife. Furthermore, heap leach opera­tions are now generally required to detoxify the heaps before abandonment. It is, there­fore, apparent that all gold extraction plants may be required to install some form of effluent treatment in order to achieve the above objectives,.

Jan 1, 1990

By J. R. Long

The Federal Bureau of Mines has pioneered the work of preparing ductile titanium on a large scale and has also determined the basic properties of this new and most interesting metal. A number of reports (1, 2, 3: 4, 5) have al-ready been published, and considerable interest has been aroused in a number of industrial and research laboratories. Some of these laboratories have also published results of their work on the pure metal. Although the properties of titanium itself are quite promising, it is apparent that considerable improvement may be expected by alloying titanium with other metals. That is, pure metals in general have shown relatively large improvements in properties when alloyed with other metals and titanium is not considered to be an exception to the rule. Therefore, the emphasis of the investigations now under way in the Federal Bureau of Mines Laboratories has been placed on the study of the alloys of titanium, particularly the titanium-rich alloys. While the main interest is in the properties of such alloys, proper direction and evaluation of the work require at least a rough outline of the phase boundaries of the alloy systems involved.

Jan 1, 1949

By F. C. Harris, S. J. Gaab, J. Sattarvand, S. Duzgun

Underground mines are inherently dangerous due to potential hazards such as fires, explosions, and caving of rock. Although these events are rare, once they occur a speedy and safe egress of mineworkers is critical to survival. Static evacuation systems use exit signs or directional lines but can get obstructed or be hardly visible in smoky or dusty conditions. This paper presents the investigation of the effectiveness of a smart evacuation technology in underground mining, where a real-time guidance system leads individuals on an optimised path to the egress while avoiding danger zones, compared to conventional practices. Participants simulated an evacuation from a virtual reality mine, using the conventional system and the smart evacuation system with real-time guidance. The highest reduction in evacuation time using the smart method amounted to nearly 40% on average. Moreover, 83% of participants preferred the smart guidance system, and agreed that it could enhance safety.

Sep 1, 2021

By R G. Moreby, S Bluhm, FávonáGlehn, C Pascoe

Resolution Copper Mine in Arizona, USA, is planned to be a 2000 m deep panel cave mine with virgin rock temperatures exceeding 80¦C in rock with high crystalline silica content, resulting in a very challenging ventilation and cooling system design. This is one of the largest copper orebodies ever found and, with a planned rock production rate of 120 kton/day. The project is currently in its prefeasibility phase and the paper discusses features of the ventilation and cooling system design which includes multiple ventilation shafts with total primary ventilation flow of about 3000 m3/s and both surface and underground refrigeration plants producing more than 140 MW refrigeration capacity. The cooling system features large surface bulk air coolers chilling all downcast air supplemented by an underground secondary air cooler system and a chilled service water system. This will be a very challenging mine to ventilate and cool but this work has demonstrated that it will be technically achievable with the application of existing technology.CITATION:Bluhm, S, Moreby, R G, von Glehn, F and Pascoe, C, 2013. Life-of-mine ventilation and refrigeration planning for Resolution Copper Mine, in Proceedings The Australian Mine Ventilation Conference , pp 125-138 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By Ralph M. Foecking

The disposal of the phosphate slimes produced by Florida beneficiation operations is perhaps the biggest single problem of the phosphate mining industry. This is an old problem which has not been solved and which is becoming increasingly severe. In a typical phosphate mining operation, the phosphate rock mined is initmately mixed with sand and clay, constituting what is known as matrix. During the beneficiation, the clay and other fine materials are separated usually at -150 mesh, and washed from the phosphate rock in a form of diluted slurry known as phosphate slimes. The quantity of slimes solids and their composition vary considerably with the location but usually represent from 25 to 35% of the ore mined. Because of the affinity that clays have for water, large volumes of water are required to separate the granular material in the matrix forming a dilute slime suspension (1.5 to 3% solids) of colloidal material, which settles very slowly, and thus requires immense impounding areas, which never becomes totally usable land. These ponds also contain about 25 to 35% of the total P205 values mined. The magnitude of the problem represented by the slimes can be appreciated better if we realize that there are around

Jan 1, 1971

The effects of process variables such as solution chemistry, flocculent type and dosage, intensity and duration of mixing, and solids type and concentration, on the performance of flocculation/clarification/thickening processes are described. System response is evaluated in terms of the specific effects on floc settling, supernatant clarity and sediment compressibility. The implications of these results with respect to industrial practice are discussed and general guidelines for direct application to plant design and operation are suggested.

Jan 1, 1993

By Branch of Editorial Services

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mineral substances; to promote health and safety in the mineral industries; to conserve material resources and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau of Mines to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue of the Bureau of Mines List of Publications and Articles describes reports and articles published during the period January 1, 1980, to December 31, 1984. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960;1 the 50-year list of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960;2 the 5-year lists of publications and articles from January 1, 1960, to December 31, 1964,3 from January 1, 1965, to December 31, 1969,4 from January 1, 1970, to December 31, 1974,5 and from January 1, 1975, to December 31, 1979;6 and the annual lists of Bureau publications and articles from January 1 to December 31, 1980,7 from January 1 to December 31, 1981,8 from January 1 to December 31, 1982,9 and from January 1 to December 31, 1983. 10"

Jan 1, 1985

By P Mesquita, A Nolan

Using a scientific-principled definition of global socio-ecological sustainability can be a useful basis for planning precious and base metal mining projects. The mining industry faces key challenges of; viability of the minerals industry; the control, use and management of land; national and local socio-economic development; environmental management; materials stewardship; and access to information. Using a framework for strategic sustainable development to assess the current reality of mine project development has resulted in identifying areas of strength and opportunities for improvement between current best practices and a desired vision of sustainability constrained by science based principles. These gaps indicate opportunities to strengthen current strategies, tools, and actions with a deeper understanding of socio-ecologic systems and a first-order, principled definition of sustainability, enabling success in moving towards achieving a sustainable society, ie sustainability. Evaluation of mine project development and their impacts on ecological and social systems using a systems perspective which recognises the underlying principles of operation, delays, feedback loops and response to change highlight specific opportunities to create value for social, economic and ecologic systems. Envisioning this future for mining projects within a sustainable society can be done by evaluating their development and operations guided by the sustainability principles. Performance indicators play a key role in measuring progress towards achieving sustainability goals yet it is necessary to consider whether indicators capture the whole systems perspective. Connected to this broader view, indicators can contribute much value to the mining industryÆs sustainability journey. This paper examines how current processes for mining projects can be developed using a whole systems perspective and measured using holistically designed performance indicators.

Jan 1, 2009

By Edward W. Parker

THE agreement of September, 1922, between the anthracite operators and the United Mine Workers of America, which followed the 54.5 months strike during the summer of that year, contained the following provision : The parties unite in a recommendation to Congress that legislation be forthwith enacted creating a separate anthracite coal commission with authority to investigate and report promptly on every phase of the industry and the parties hereby ask the President to request the enactment by Congress of the recommended legislation. The continuance of production after Aug. 31, 1923, shall be upon such terms as the parties may agree-upon in the light of the report of the Commission.

Jan 1, 1924

By R. C. Emmett

Waste treatment in the mining industry is by no means a new problem to this field. In a sense, the entire process from ore to finished product is one of waste treatment - the separation of a relatively minor quantity of desired component from valueless material. Where it has been necess-ary or economical to practice conventional waste treatment or pollution control methods, such as dust collection, water recovery from tailings, or impounding of residues for future treatment, this has been done. Generally the containment of hazardous pollutants such as arsenic and cyanide also has been followed in modern times. But it is only recently, with the public outcry for the elimination of all forms of pollution, "that the industry has been forced to solve what often appears to be a myriad of difficult and costly waste treatment problems, or be faced with the alternative of closing down the operation. It is the objective of this paper to describe new as well as conventional approaches to these problems, specifically as might be applicable to liquid-solids separation methods. Host wastes in the industry are present either as solutions or slurries, or can be most advantageously handled by conversion to this form, such as in scrubbing noxious gases and dusts with water. Separation of the solids and purification of the aqueous effluents are, therefore, often the principle problems.

Jan 1, 1971

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By T McLeod, B Catto

AngloGold Ashanti Australia’s (AGAA) Tropicana gold mine (TGM) geology department seized the rare opportunity of building a new geology department for a new operation: the philosophy, the people and the processes. Not satisfied with the status quo, or simply repeating what was familiar and already known, the vision was for an innovative, agile, multidiscipline, high performance team, capable of delivering on expectations.To achieve this, the geology department has operationalised key components of human resource management (HRM).This paper describes the operational design and implementation of key HRM components: job analysis, organisational design and organisational development. The benefits of this approach are presented in terms of engagement and autonomy in roles, opportunity for role variety and flexibility of the organisational structure. The result is a geology department that provides the functions of mine geology, resource development, regional exploration, survey, data management, geographic information systems (GIS), resource modelling, scheduling, sample preparation, resource coordination and hydrogeology, and even geotechnical engineering for a year!Considerations for application in other geology departments are presented in terms of fundamental requirements and lessons learnt. Fundamental requirements for success have been the sustained support of the general manager, valuing the scrutiny that comes with continuous improvement, high quality HRM systems and tools within the organisation, and a committed leadership group within the department. One of the most important lessons learnt is that a robust process of ‘induction to role’ is critical – the process of familiarising new starters with who we are and the way we work.CITATION:Catto, B and McLeod, T, 2017. Rewriting the rule book – geology organisational design, in Proceedings Tenth International Mining Geology Conference 2017, pp 137–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017