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By D. C. Panigrahi

The paper presents the application of Object Oriented Programming approach for the development of a network simulation model based on nodal pressure method using linearised flow equations. The convergence and computational efficiency of the algorithm have been investigated. Finally the paper re- ports the validation of this algorithm in actual field conditions.

Jan 1, 1996

By H. Hejny

The objective of the project is to construct and operate a pan-European underground drainage and minewater management research centre, which would be the hub for data gathering and dissemination in real time of new data to users for analysis and interpretation, as well as serving as a model for consistency, for other centres at key water management sites throughout Europe which would feed data in real time through the hub. The data from the centre will be essential for informing River Basin Management Plans arising from the EU Water Framework Directive, which is an important driver for the project. The implementation of this Directive sets out a requirement for all Member States to develop River Basin Management Plans for all water resource systems. The facility would be a major contribution to sustainable water management in Europe.

Jan 1, 2007

By A. T. Yu

The quest for ore in an open pit is fundamentally an earth moving proposition. This thesis is vividly underscored by the rapidly increasing volume of waste to be removed in newer mines, where in some instances waste to ore ratios have reached as high as 20 to 1. Continuing depletion of high grade reserves, greater demand for raw materials, coupled with ever climbing labor costs, have made the problem still more pronounced and the need for more effective means of earth moving in an open pit even more acute. A conservative approach to the problem has been to upgrade the sizes of conventional earth moving equipment such as shovels and trucks. In many open pits, particularly in the C.S., this has been responsible for the generally down- ward trend of earth moving costs. None the less, the investment costs of these machines are high, and their gigantic engines are seldom fully utilized. Moreover, a large number of operators are required and maintenance remains relatively high. Unfortunately most people have felt that no other viable alternative was in sight within today's technological capabilities.

Jan 1, 1973

By James E. Breland

Society's growing concern over the number of deaths and serious injuries occurring in coal mines, coupled with a growing sentiment to develop and promulgate improved mandatory health or safety standards, was no doubt the basis for passage by Congress of the Federal Coal Mine Health and Safety Act of 1969, being Public Law 91-173 approved December 30, 1969. Even prior to passage of the Act, strong reaction was quick to arise concerning the effect of such legislation upon the coal mining industry. Initial response varied from mild forms of criticism to' the expressed fear of complete suspension of operations and mine closings. Primarily responsible for these early forms of skepticism were speculative or fanciful cost estimates which led operators to contemplate a less than prosperous existence. However, in spite of this unfavorable outlook, the majority of the operators have faced up to the situation and have been striving to comply with the Act and the regulations issued thereunder. While encouraging strides have been made toward implementation of the Act, it must be recognized that noticeable results have been attained only through many months of determined effort and, as anticipated, at quite heavy expense to the operator.

Jan 1, 1973

By T. R. Ellis

The author is the leader of the Extractive Industries Task Force of the International Valuation Standards Committee. The Task Force has developed an Extractive Industries section for inclusion in the International Valuation Standards (IVS). The Extractive Industries Guidance Note provides comprehensive standards for valuation of all minerals and petroleum industry property types for all valuation/appraisal purposes. The document is scheduled for release as an exposure draft for public comment by December 2003, then it will be finalized for publication in the IVS in mid-2004. This paper discusses the content and philosophy of the Extractive Industries Guidance Note within the context of the framework of the IVS. It also discusses the international implications and implementation of this IVS addition.

Jan 1, 2004

By Philomene Verlaan

The Code for Environmental Management of Marine Mining (the Code) was adopted in 2001 by the International Marine Minerals Society (IMMS) following extensive and wide-ranging consultation, and updated in 2002. The Code provides a framework and benchmarks for development and implementation of an environmental program for a marine exploration or extraction site by marine mining companies, and for stakeholders in governments, NGOs and communities in evaluating actual and proposed applications of environmental programs at marine mining sites. The Code provides for its review by IMMS after five years, with a focus toward possible modifications based on experience with its implementation and in light of developments in the field of marine mining and associated environmental practices, in consultation with the marine mining industry and with other stakeholders at marine mining operations. As the review of the Code is now due, to begin the process, this paper will present an analysis of the Code and initial suggestions for its modification. Keywords: marine mining, marine environment, sustainable development, marine environmental risk management

Jan 1, 2008

By J. G. Nalven, J. A. Sturgess

On July 1, 1999, most domestic metal mines will have to report releases of toxic chemicals into the environment for the first time as required by SARA Title 313. Some of these reportable releases will appear huge in relation to reports by other industries. The reasons for the potentially large reportable releases, special considerations for mining operations, and strategies for dealing with the reports are described. Data composited from experience with several mining companies is presented in the context of a typical goldmine.

Jan 1, 1999

By L. G. Wilson

In order to comply with time limitations imposed by this symposium, a very narrow but nonetheless interesting segment of the market has been chosen for discussion of the preparation of a tailor-made product to meet a specific need, and in view of the fact that the barite market is one of the oldest and one of the broadest non-metallic mineral markets in the world, it is necessary that we place this in perspective. Of a recent world annual production; (i.e., 1966 figures released last year in MINERALS YEARBOOK), of some four million tons, the United States consumed over 1/2 million tons, of which approximately 950,000 tons were produced domestically and approximately 700,000 tons were imported. Of this total, something approaching 90% was used for drilling-mud weighting, and of the balance, all but about 60,000 tone is consumed in the production of glass, barium chemicals, aggregates, and other minor uses; thus we are really taking a look at a very minute, however important, and very selective, portion of the total barite-market. The real meat of this paper, after eliminating all irrelevant uses of barite, and delineating the area of discussion, resolves itself into the approach to a favorable marketing area and a specific attack on that area. Cost, to the user, has been, patently, a function of distance, as the basic price of barite has varied very little over the years until recently, and freight rates have been the governing factor. Conversely, the seller of barytes must make concession in the plant price to compensate for distance, if he is to successfully compete.

Jan 1, 1969

By A. C. Burrow, R. P. King

A dynamic model that predicts the variation of carbon content with time in the argon-oxygen decarburization (AOD) process has been developed. The model recognizes three distinct zones in the AOD vessel: the tuyere region in which the blown oxygen reacts very rapidly with the metal components in the molten alloy; a region in which bubbles of inert gas and oxide drop lets rise through the molten alloy; and a zone in which the slag layer can interact with the molten alloy. The process is dynamically controlled by the rate at which dissolved oxygen, produced on the surface of rising oxide droplets, and dissolved carbon diffuse through the molten alloy to react at the surface of the rising bubbles. The rate at which carbon and oxygen react on the bubble surface is assumed to be intrinsically very fast. Predicted decarburization rates compare reasonably well with rates measured in the AOD vessel at Middleburg Steel and Alloys. The model has been developed primarily to allow development of a time-optimal blowing stategy for the AOD vessel.

Jan 1, 1990

By Peter Erlynne

Rising costs have affected the cost of operating and install­ing crushing circuits, just as they have affected every other area and there is little possibility that the cost cycle is about to be reversed - power costs, wear materials costs and labour costs continue to increase but a basically stable gold price makes little allowance for these cost increases. Additionally, lower grades of ores being worked, and harder feed materials have a significant effect on the potential for higher processing costs. There are, of course, options for size reduction - some of them newer than others - some are suitable for certain types of ores and less suitable for others and it can sometimes be difficult to ascertain the accuracy of anticipated results before plant design and con­struction are completed - by which time the capital outlayed will preclude a change to another method ofreduction. Nordberg's patented WaterFlush Technology has the potential to change the way that Ball Mill Feed production is viewed: Some of the elements that must be considered are: • Capital Cost • Operating Cost • Efficiency • Flexibility • Availability • Control • Support Efficiency • Expertise • Spares availability • Environmental considerations

Jan 1, 1995

By V. Rajaram

V. Rajaram's paper does not accurately reflect the status of Eastern oil shale development as it stands today. Today, there are numerous firms and research organizations pursuing development of the Eastern oil shale resource. Details of the current projects can be found in the symposium proceedings for the 1985 Eastern Oil Shale Symposium held in Lexington, KY, in November 1985. Additionally, the comparison of the Paraho and HYTORT processes is invalid because the HYTORT process design used it not an accurate representation of the HYTORT process. I will briefly address this point. It is disconcerting to see the author reference hydroretorting work conducted at the Institute of Gas Technology (IGT) (circa 1978) in the introduction, which indicates hydroretorting (the HYTORT process concept) yields of up to 250% of the Fischer Assay oil yield, and then turn around and base the remainder of the paper on the 1981 "Synthetic Fuels From Eastern Oil Shale Report," which depicts the HYTORT process as yielding only 115% of Fischer Assay. Indeed, work conducted at IGT to 1981 indicates commercial oil yields for the HYTORT process would be in the range of 200% to 210% of Fischer Assay. A more thorough literature search by the author would have yielded a 1981 publication by Schora et al., entitled "Update on the HYTORT Process" presented at the Symposium on Synthetic Fuels From Oil Shale in Nashville, TN, October 1981. This paper thoroughly discusses the shortcomings of the referenced study with respect to the HYTORT process. For the interested reader, I can also recommend a June 1984 report entitled "An Economic Comparison of Five Process Concepts for Using Eastern Oil Shale," published by Los Alomos National Laboratory (LA-10106-MS, Parkinson et al., NTIS No. DE84-015981). This study applies a realistic HYTORT design (circa 1982) and indicates that HYTORT is the most econom¬ical method of processing Eastern oil shales (about $20/bbl less than Paraho). Additionally, completion of the HYTORT feasibility study in June 1983 by Phillips Petroleum Co., Bechtel Group Inc., HYCRUDE Corp., and IGT has resulted in development of designs that will make the use of HYTORT on Eastern oil shales even more economic. HYCRUDE Corp., a second-tier subsidiary of IGT, is involved in commercialization and licensing of the HYTORT process and is active in efforts to develop the Eastern oil shale resource. As such, I am disappointed to see outdated material that has the potential for adversely affecting development of Eastern oil shale resources published in MINING ENGINEERING. I can only hope that this response will serve to mitigate any negative opinions that may have been formed. Today, activity in commercializing Eastern oil shales dominates the oil shale scene in the US and indicates a realization of the potential for these shales. Reply by V. Rajaram I appreciate the updates on the HYTORT process provided by R.C. Rex, Jr. I hope that Hycrude's work will lead to the funding of a pilot plant to demonstrate that yields of greater than 200% of Fischer Assay can be achieved in a commercial plant using eastern US oil shales.

Jan 1, 1987

By S. K. Kawatra, S. Valluri

With increased CO2 emissions from steel and coal industry, there is great opportunity to capture CO2 and utilize the captured CO2 for economic advantage. The primary goal is to develop energy-efficient processes that reductively couple CO2, an abundant and renewable carbon source, for the production of value-added chemicals such as methanol, ethanol, and oxalic acid. These chemicals can be used elsewhere in the refining process or sold as valuable by-products. Geological sequestration, in comparison, has no economic return. Current CO2 utilization research at Michigan Technological University focuses on electrochemical reduction of CO2. Electrochemical reduction of CO2 to hydrocarbons and other chemicals is a complex multistep reaction with adsorbed intermediates. The exact reaction mechanisms leading to various products are not clear from the literature to date and will likely change over the range of conditions like pH, electrode potential, electrolyte medium, catalyst, etc. This paper will present different ideas and their viability to utilize CO2 as a feedstock to produce several value-added compounds. INTRODUCTION Carbon dioxide (CO2) emissions into the atmosphere will need to be drastically reduced to curb the various undesirable effects of climate change. The large contribution in total CO2 emission originates from coal or natural gas power plants, and a considerable amount from steel plants. Average CO2 emissions in the US from steel industry is 2.9t CO2/t steel (Global CCS Institute 2013). Capturing the available CO2 from the steel and coal industries for economic advantage is a win-win situation for the industry. This technology is not only important scientifically but is also vital for a sustainable future. The various ongoing investigations can be categorized as biochemical, thermochemical, photochemical, and electrochemical approaches. Among these, the electrochemical method shows the most promise as an efficient form of CO2 conversion technology, because of its many advantages like high reactivity under ambient conditions and good extensibility from small- to large-scale processes1 BACKGROUND Extensive research has been done on the chemistry of transforming carbon dioxide into more useful products. Methods are known to convert carbon dioxide into a wide variety of substances, including methanol, isobutanol, carbohydrates, methane, carbonates, urea, formic acid, oxalic acid, carbon monoxide, epoxides, formaldehyde, and so on. Several of these (carbohydrates, formaldehyde, isobutanol etc.) are primarily results from biological processes. The rest are results of strong reduction reactions or electrolytic reduction. In short, electrolytic reduction can be used to form methane, methanol, formic acid, oxalic acid, carbon monoxide from carbon dioxide2. CO2 reduces at the cathode in an electrolysis cell. These processes have the general form of generating the carbon dioxide anion radical (2⋅−) and allowing it to react with itself or the electrolyte3. Catalysts can be added to influence the formation of the anion radical or to suppress side reactions3. The electrolyte, catalyst, voltage, electrode material and CO2 content are all known to effect the reaction pathway. Table 1 shows the overall reactions and energy requirements for electrochemical conversion of CO2 to chemicals

Jan 1, 2019

By L. B. Kirk, A. R. Kirk

At New World, Au-Cu-Ag mineralization occurs in stratiform car-bonate-hosted, massive sulfide-iron oxide, and skarn-replacement deposits. Regional pyritic-alteration, local massive sulfide mineralization and mine wastes generate acid drainage within the district. Water quality improves down gradient through dilution and mixing of acid and metal-rich mine water with bicarbonate-rich, low-metal surface and groundwater, and precipitation of metal-rich ferrihydroxide phases. Natural deposits of ferricrete indicate that pre-mining ARD has occurred, providing important clues to pre-mining water quality. The geoenvironmental model identifies the Cu-skarn mineralization as the primary target for ARD management. Closure success will be limited by the geoenvironmental nature of the natural mineralization.

Jan 1, 2004

By D. H. Davidson

In situ leaching (ISL) of copper has the potential of reducing both capital and operating costs for copper production. The ISL process combines surface facility (SX/EW) and wellfield operations, each of which must process the same total flow rate and pregnant liquor copper concentration. Commercial cost data are only available for SX/EW facilities. This paper discusses: the interaction between the principal wellfield costs associated with well modules, and wellfield start?up with SX/EW costs; how to estimate what the level of wellfield costs must be to optimize DCF/ROR; and how to relate these wellfield costs to orebody geologic and mineralogic characteristics.

Jan 1, 1988

By Robert Y. Lamarche

INTRODUCTION Production of chrysotile asbestos from the northern Appalachians has been going on for 100 years and, on the basis of known reserves and the present rates of mining, appears assured of continued production for at least another 25 to 30 years. In spite of this, mining companies and government agencies are showing an increasing interest in exploring for chrysotile asbestos throughout this region and elsewhere in the world, implying that increases in the rate of consumption are envisioned. This chapter describes the geologic and tectonic settings surrounding these important chrysotile deposits, with emphasis on those in southern Quebec that yield about 90% of the total production from the northern Appala- chians. Detailed descriptions of a few individual deposits are also given, along with exploration guidelines aimed at facilitating the discovery of additional chrysotile deposits. One section of this chapter deals with the origin and mode of formation of the chrysotile deposits in the light of modern day concepts of plate tectonics. The objectives of this chapter are to give a brief description of the geologic and tectonic settings of the ultramafic rocks in which the numerous chrysotile deposits of the northern Appalachians are found; to describe a few of the individual deposits; to give a few exploration guidelines for those interested in exploring for new asbestos deposits in similar geologic environments; and to propose a new model for asbestos genesis in light of the recently developed theories of global tectonics. As this chapter is based almost entirely on field and laboratory observations, rather than on the study of experimental laboratory models, most of our deductions and suggestions are empirical in nature and may be interpreted in more than one way. The interpretations we have selected seem to offer, we feel, the best explanation of observed geological phenomena (Lamarche and Wicks, 1975). This region had a production capability in 1979 of close to p.5 Mt of chrysotile asbestos with 92% of this tonnage being derived from the deposits of the Eastern Townships of Quebec. With known resources, which now stand at between 36 and 40 Mt of fibers, this production capability seems assured for the next few decades. In spite of all known reserves of chrysotile asbestos, which now stand at between 36 and 40 Mt of fiber in this region alone, mining companies and government agencies are still showing a good deal of interest in exploring for new sources throughout the world. GEOLOGICAL SETTING The asbestos deposits at Baie Verte in eastern Newfoundland, Thetford Mines, Black Lake, Asbestos in southern Quebec, and Belvidere Mountain in Vermont, all occur in partly serpentinized ultramafic rocks that are part of the Lower Paleozoic ophiolite complexes of the northern Appalachians [Cady, Albee, Chidester, 1963, Chidester, Albee, Cady, 1978, Lamarche, 1972,1973, Laurent, 1973,1975, Williams, Hibbard, Bursnall, 1977, Norman and Strong, 1975). The deposits to the northeast of Thetford Mines, on the other hand, are found in a more highly serpentinized ultramafic body known as the Pennington dike, whose spatial, genetic, and chronological links with the ophiolite masses proper have not as yet been adequately resolved. The Appalachian ophiolites are part of an ultramafic belt (or belts), that extends from northwestern Newfoundland, through Quebec and Vermont. Fig. 1, and southwestward as far as the

Jan 1, 1986

By Barry R. Doyle, Ilsley Roger C., John Ramage

It was anticipated that settlement would occur when tunnels were excavated in weak organic soils with high groundwater levels in downtown Milwaukee. Because of the potential for damage to adjacent buildings, an approach was devised during the design to address this issue. In order to do so effectively, estimates of settlement trough geometry were made; buildings identified which were potentially at risk; the means of settlement measurement designed; and threshold limits of settlement and courses of action specified. Bid items were provided for underpinning the critical structures. The approach addresses the design issues and delineates the sharing of risk between the owner and contractor. The predicted and actual performance experienced are also discussed.

Jan 1, 1989

By Patricia O. Milley

Two years ago, AlliedSignal embarked on a journey to improve QUALITY. However, the focus of this endeavor was on the CUSTOMER and not the traditional product focus. It wasn't that a focus to improve product quality wasn't fruitful in the past. We've practiced it in the chemical industry for many years with significant results. But our industry today is in a survival mode and yesterday's way of doing business is simply not good enough. In the mining industry, we have to make lug strides in how we do business or face losing our customer base. As you are well aware, other parts of the world are importing our technology at a rapid rate. We must work smarter to stay ahead of our customers ever more demanding need for higher quality at lower prices. With this as a driver, throughout the Corporation we reviewed in depth how we support our customers to keep them competitive and sought to eliminate work which did not help them reach this goal. Our first year of emphasis was on tools: how to hold meetings, gather data, and how to make decisions. This sounds very basic, I know, but you can't begin to imagine how productive meetings can become when you start with an agenda and prework delivered days in advance, and agree at the start of the meeting what should get accomplished. In the second year, we applied these tools to our work processes. We mapped how we do our work, scrutinized each step for value to the customer, and then set to work on how we could do things better. The areas we concentrated on were customer linked commercialization of new products, manufacturing and materials management. Our discussion today will focus on the commercialization of new products.

Jan 1, 1994

By Gregory Owen Lewis, Wendy Bouwer

Various processing strategies have been implemented in an effort to limit the loss of gold, during leaching, to the naturally-occurring carbonaceous 'preg-robbing' constituents present within certain gold bearing ore sources. Certain processing routes include complex and costly pre­treatment steps to reduce the negative effects of the preg­robber prior to dissolution, while others adopt a simpler direct leach/recovery approach. Process selection is largely dependent upon the gold deportment and the nature of the preg-robbing constituents within the particular ore. In the case of carbonaceous ores in which the bulk of the contained gold is available to direct cyanidation, carbon-in­leach (CIL) technology is generally applied with varying degrees of success. The effectiveness of the CIL route is governed by the competitiveness of the preg-robbing constituents in relation to activated carbon for the preferential adsorption of the solubilized gold. Trials have shown that the DOWEX MINIX strong-base gold-selective ion exchange resin has gold loading characteristics superior to those of activated carbon. The faster gold loading kinetics, together with the higher capacity of this resin, favour its use in an in-leach application as a more effective adsorbent for complex ores. This paper introduces the alternative resin-in-leach (RIL) technology, compares the metallurgical responses to RIL processing of different problematic ore sources, and discusses the interaction between various process conditions. Selected results from laboratory and pilot-scale testwork are presented to highlight the discussion.

Jan 1, 2000

By A. Ferreira Morgado, P. de Souza Santos

The sodium smectitic clays (bentonites), have more industrial applications in that class of mineral, a driving force to obtain this mineral. In Brazil, there are several occurrences of smectitic clays, unfortunately they are polycationic, with a distribution of several exchangeable cations, where the cation sodium occurs in minor quantity. In this work, the original polycationic smectitic clay was firstly proper characterized and then treated with sodium carbonate obtaining homoionic sodium smectitic clay. The rheological tests in the optimized sodium smectitic clay showed good results for drilling fluids, typical of a sodium bentonite ones.

Jan 1, 1999

By O. Fernandez, M. Vesely

Abrasive grinding, leading to ultrafine product and "critical size" material buildup inside the mill, is proposed as the cause of high power consumption and low capacity in many fully autogenous grinding processes. Addition of steel balls (hence, semiautogenous grinding) or pebble removal and separate crushing have been used, with different efficiencies, to overcome the problem. Information and data for the conceptual analysis, basic design, and operation of a pebble crusher at the Los Bronces semiautogenous grinding plant is presented along with data showing a production increase of 1000 t/d (1100 stpd) and significant operating costs savings.

Jan 1, 1987