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By A. Gronningsater

Introduction As is well known, the fight between the blast furnace and the reverberatory furnace in copper smelting during the second decade of the century ended with a victory for the latter, a result which must largely be attributed to the introduction of flotation methods. To my knowledge, no new blast furnace has been blown-in at any American copper smelter since the War. As the metallurgy of nickel, up to and including matte smelting, is generally considered a close parallel to that of copper, the introduction of reverberatory smelting in the big new smelter of the International Nickel Company at Copper Cliff, built in 1928-30, seemed a logical adherence to a well established trend. In view of these facts, considerable comment was made when Falconbridge Nickel Mines decided to retain the blast furnace in their smelter built about the same time, in 1929. A presentation of the reasons governing this choice should therefore be of interest. The basic principles underlying the Falconbridge practice, and the considerations guiding the successive steps in the operations, will be discussed in the following. To understand the problems involved, the character and mode of occurrence of Sudbury ore must be kept in mind. Large amounts of disseminated ore are generally present. Although the gangue usually runs only about 50 per cent Si02, the ore hoisted as a rule contains more silica than needed in the smelting operation; until recently this excess was removed entirely by hand picking (in later years supplemented by magnetic sorting methods), a difficult and not very satisfactory method, in which 'the border line between ore and waste is entirely arbitrary, and therefore too much depends on the judgment of the picker.

Jan 1, 1934

By Creasey J. W, Huntington J. F

Faults cutting the Lithgow and Katoomba seams in some collieries of the Western Coalfield can be classified, on the basis of spatial pattern, into three principal groups: meridional swarms of closely spaced minor faults and associated joints, with throws of less than 0.5 m and with exceptional faults of up to 5 m; isolated interswarm strike-slip faults in the Lithgow seam and widely spaced strike-slip faults in swarms in the Katoomba seam; and low-angle normal faults associated with the Lidsdale-Lithgow seam split.Orientations of faults and coal cleats in the coalfield are presented on stereoplots and histograms, as a basis for an analysis of fault dynamics. The low-angle normal faults were found to have been formed only along the Lidsdale-Lithgow seam split, and before the high-angle faults. The origin of the high-angle normal faults in the meridional swarms is discussed and it is suggested that basementcover interactions must have occurred. This suggestion is supported by geophysical evidence. Low-amplitude monoclines in the coal seam, and the spacing of swarms 0.9 to 4.5 km apart, may be due to the underlying basement structure.It is clear that postextensional compressive deformation of swarms in the coalfield gave rise to shortening by minor thrust development, and probably also caused the synchronous strike-slip movement on pre-existing normal faults. There is evidence to show that isolated interswarm strike-slip faults in the Lithgow seam, and widely spaced strike-slip faults in the Katoomba seam, may have originated synchronously with such thrusts. The axis of maximum principal compression ('71) for the thrust event was inferred to be near horizontal and aligned approximately E-W. Recent rock mechanics measurements of the present day stress field indicate a similar stress configuration.

Jan 1, 1981

The widely accepted kinetic model for the gaseous reduction of hematite is critically examined. The formation of the wustite layer during internal reduction cannot be explained in terms of solid-state diffusion. Present evidence indicates the existence of a micropore system in the wustite adjacent to the magnetite with the gas/solid type of reaction occurring not only at the iron/wustite interface but also at the wustite/magnetite interface. During the partial reduction of dense hematite pellets, in a controlled atmosphere, porous magnetite and wustite are formed as products. The mean pore size, as measured by mercury injection, increases with time at constant temperature and with temperature increase over the range 6500C to 950°C. The sizes of the pores indicate that Knudsen diffusion is the principal gaseous transport mechanism across thick layers of magnetite or wustite.The kinetics of the gaseous reduction to iron are consistent with a mixed control mechanism involving the interaction of gaseous diffusion effects with a first order reversible chemical reaction at the iron/wustite interface. Because of the larger pore sizes in the iron layers, ordinary molecular gaseous diffusion must be the principal transport mechanism. The usual experimental methods used for establishing the validity of chemical rate ~ontrol are incapable of differentiating between the mixed control- mechanism and exclusive chemical control.Some implications of mixed control kinetics are developed, including a predicted independence of rate on reducing gas pressure at higher pressures.INTRODUCTIONAn extensive literature review of the reduction of iron oxides has been compiled recently by Themelis and Gauvin (1962). From the large number of papers published and the widely divergent opinions of workers in this field, it appears that a simple unified quantitative analysis of reduction kinetics is not possible. The aim of the present paper is to show that a major cause of confusion is due to the attempts of many workers to interpret experimentally observed reaction rates in terms of a single rate controlling mechanism without due regard to other rate processes which must occur simultaneously.Some of the differences in behaviour reported for particles...

Jan 1, 1964

By G. G. Oberfell

THOUGH the largest volume use of natural gas has been, is. and in all probability will continue to be as a fuel for domestic and industrial heating, it has various market outlets, both as a fuel and as a raw material for the chemical industry. Natural gas is a preferred type of fuel where ease of control, fuel uniformity, and freedom from ash are of primary importance. Other industrially important uses are as a source of carbon black and as a fuel in various low-cost heating operations. Many other uses are of varying importance and new potential uses are continually being uncovered, some being of economic importance to the gas indus¬try as a whole, but most of them involve such small volumes of gas that they are only of passing interest. Since various products extracted from natural gas and recovered as by-products from petroleum refining, such as liquefied petroleum gas and fuel oil, are being utilized in many industrial and domestic heating applications, some consideration will have to be given such materials in order to present a reasonably complete story of the importance of natural gas. Some of these materials may prove to be transient competitors and will not be available when more profitable uses are found for them. Meanwhile, however, the potential volumes of such materials available, the current volumes being marketed, and the nature of the utilization are considered as constituting an essential part of the over-all fuel picture.

Jan 1, 1946

By Sean Gallagher, Gene Wilson, Christopher Mark, Craig S. Compton, Gregory M. Molinda

Falls of small pieces of rock from between roof bolts continue to cause fatalities and to injure hundreds of coal miners each year. Roof screen is the most effective way to prevent these incidents, but some mines are reluctant to use it because they believe installing screen can be awkward, expensive and time-consuming. The most common type of roof bolting machine used in mines today is the dual boom, outside-controlled roof bolter. Mines who install roof screen using these machines have developed some machine modifications and techniques to ease roof screen installation. This paper describes some successful techniques and machine modifications that are being used in productive mines to assist with roof screen installation. Since the material handling involved with roof screen installation can expose miners to an increased risk of musculoskeletal injuries, the National Institute for Occupational Safety and Health (NIOSH) ergonomists, designed machine modifications and implemented a series of tests to evaluate roof screen handling procedures for outside-controlled, dual boom roof bolting machines. Roof screen installation can also have a positive economic impact on a mine by reducing the cost of injuries, workers’ compensation, required spot or re-bolting, and clean-up of long term travel and belt entries.

By A Palynchuk

The development of welded pipe has paralleled the general industrial development and, in particular, that of the petroleum industry. The petroleum industry's need for high-grade, economical pipeline material to make many 'of its projects feasible has been a significant factor in the development of light-wall, high-grade welded pipe. The modern welding processes, such as high-frequency, electric resistance, flash, submerged arc, etc., have some basically different characteristics. The modern high-frequency weld mill is a complex of specialized equipment that is integrated into a production unit. Each component in the unit performs a specific function in the production process. Quality control must be built into the process on an operating basis and, to maintain the quality required for pipeline standards, must be more than a policing operation. The further development of the welded pipe industry will be determined by changing and increasing demands. The technical and economic views and requirements that will influence the development have to be resolved.

Jan 1, 1964

By H. Ikeda

INTRODUCTION [Slide 1] The Role of the MMAJ Ladies & Gentlemen, it is a pleasure for me to be able to make a speech at this SME annual meeting, representing the Metal Mining Agency of Japan. [Slide 2] Today’s Topics In my presentation today, I would like to divide my topics into four parts. First of all, I would like to describe the current situation of Japanese non-ferrous metal mining and mineral processing industries in Japan. Secondly, the supply and demand of non-ferrous metals in Japan. Thirdly, I would like to spare some minutes on the overview of overseas development by Japanese mining companies. Finally, since some people may not be sure what the Metal Mining Agency is or what this Agency, I would like to briefly introduce the Metal Mining Agency of Japan.

Jan 1, 2001

By J. M. Garcia

This paper highlights several management practices from the oil and gas industry to support the proposition that financial performance in the finite, non-renewable resource business relates more to upstream rather than downstream activities. Based on the analysis of nine oil and gas companies, this study supports a previous study involving fourteen mining companies that showed reserves growth is one of the main levers of value creation in mining. Interestingly, this study also finds that the oil and gas industry has been historically more profitable than mining. The reason, it is argued, is that oil and gas companies count on management practices that focus primarily on the upstream segments of the business, compared to the traditional downstream focus of mining. This paper delves into these ideas to conclude that what mining may need to improve its competitive advantage is a new organizational framework. Another conclusion is that the upstream management focus is vital not only for strategy formulation in the resource business, but also for policy formulation in economies based on the export of finite, non-renewable resources.

Jan 1, 2011

By J. A. Kost

A survey of 80 coal producers was conducted to determine the extent and scope of respirable dust control research for underground coal mines and the current methods employed to control respirable dust. Results of the survey showed that proper face ventilation and an adequate water spray system are sufficient to comply with mandatory standards in room and pillar mining. Difficulties still exist with longwall equipment, auger miners and buring machines. In these cases, known dust control techniques are not sufficient to obtain compliance. Present state-of-the-art face ventilation and water systems were discussed in addition to the sampling program.

Jan 1, 1980

By Jonathan Baggett, Nino Ripepi, Amin Abbasi, Richard Bishop, Juan Monsalve, John Hole

This work focuses on the operational and safety issues associated with karst voids in large opening underground mines. Issues include water inrush, structural instability, and engineering uncertainty in these environments. Coupled with the fracturing prevalent in folded sedimentary rocks, karst voids are complex and challenging ground-control risks. Traditional methods of predicting karst void locations, such as probe drilling, are impeded by the inconsistent spatial distribution and variable sizes of the features as reported by Li et al. (J Rock Mechan Geotech Eng:232–242, 2010) and Hassan et al. (Procedia Chem 19:737–742, 2016). Ground-penetrating radar (GPR) is a geophysical technique that transmits radio waves into a medium and subsequently detects reflected waves via a receiver. The travel time and energy of received signals are then processed and interpreted. The difference in conductivity and dielectric permittivity between limestone and open karst cavities causes strong reflections. GPR is frequently used as a geophysical surveying technique in several industries; however, there is a lack of published research on underground mining GPR applications as reported by Zhao et al. (2015a; Geophys J Int:62–71, 2015b) and Eskelinen and Pellinen (Constr Build Mater:888–898, 2018). The purpose of this work is to demonstrate the use of GPR in an underground stone mine and to discuss the importance of karst void detection ahead of mining.

By Lee W. Abramson, William H. Hansmire

The H-3 Project is planning, design, and construction of a 10-mile (16 km)-long final segment of new highway that traverses the Koolau mountain range in Oahu. Interstate H-3 traverses North Halawa Valley on one side of the Koolau Mountains and Haiku Valley on the other side. The project includes a tunnel through the mountain range. The one-mile (1.6 km)-long twin-bore Trans-Koolau Tunnel will have two lanes in each direction. The total roadway width including shoulders in each bore will be 38 ft (11.6 m). The geologic and geohydrologic conditions along the alignment present a variety of tunneling problems. Geologic conditions consist of volcanic materials deposited generally in fairly thin basaltic layers. These volcanic materials generally weather down to "MH" soils which are compressible but relatively strong. Perched ground water that is recharged by heavy rainfall is present in the mountains. The paper presents results of initial geologic surveys and exploratory boring, and plans for exploratory tunneling and testing programs. A site specific classification method developed to characterize the weathered profile is presented.

Jan 1, 1989

A Study on Main and Interaction Effects of Operating Variables of Column Flotation

Sep 13, 2010

By Wilson Blake

Rock preconditioning in advance of mining was shown to be an effective means of rock-burst control based on the results of a field demonstration carried out on the 7700 level of the Hecla Mining Company's Star mine. Mining through the preconditioned zone was characterized by greatly reduced rates of released seismic energy and no bumping or rock bursting occurred within the preconditioned zone. Mining above the preconditioned zone was characterized by greatly increased rates of released seismic energy and rock bursting, particularly where the vein became very narrow in waste zones. This increased incidence of rock bursting points out the need for stope preconditioning to be carried out on an entire stope block basis. The data obtained from the monitoring of the mining above the preconditioned zone on the 7700 level will be extremely useful in evaluating any future stope block preconditioning experiments on the lower levels or the Star mine.

Jan 1, 1980

By M. Dobbins

The advent of the more efficient and effective rare-earth roll (RER) separator in the early 1980?s began a new era of dry magnetic separation. The RER units quickly became the separator of choice within the materials processing industry. Though RER separators are now commonplace throughout the world, only modest advancements have been made to the original design. This paper details recent, more significant, rare-earth magnetic separation developments. These developments maintain the best features of existing technology while minimizing shortcomings. The discussion includes discerning features that aid in better metallurgical performance. Also discussed are improved mechanical aspects that allow for both easier operation and maintenance. Performance details from various test programs are included.

Jan 1, 2009

Two events during the past decade have combined to effectively alter the role of the geologist working in Papua New Guinea. The gold boom of the 1980s resulted in a substantial increase in the general awareness at village level of mining companies, gold and landowner issues, and as a consequence of the Bougainville tragedy, landowners are also very much aware of the potential problems of a mining operation in their area. Landowners know they have the power to remove a company from a project area, and government has shown itself to be virtually powerless and unable to help the company effectively. During a considerable proportion of a project's development time, the project geologist is viewed in the eyes of the local community as the 'company'. Good landowner relationships are nurtured over a reasonable time period and the input of the geologist is significant in determining the eventual fate of company-landowner relationships. The initial impressions of the company, gathered by the local community, will have a far reaching impact on the nature and direction of their future exchanges with the company.

Jan 1, 1991

By G. J. Ackland, K. Saksl, F. Brunke, M. Kohnke, B. Tegner, C. Siemers

The application of titanium alloys is limited to 550°C due to their poor oxidation resistance. It is known that the addition of niobium decelerates the oxidation of titanium alloys whereas elements like vanadium do not improve titanium’s oxidation resistance. The underlying mechanisms are not yet well understood. In the present study, different binary titanium-niobium and titanium-vanadium alloys as well as commercially pure titanium were investigated. Oxidation experiments were carried out at 800°C up to 288 hours followed by metallographic analyses to study the oxide layer morphology as well as the microstructure at the interface. Energy-dispersive X-ray spectroscopy mappings were used to identify possible changes in the distribution of the alloying elements. In addition, micro-focused hard X-ray experiments were performed to layer-wise analyse the phase composition in selected samples. As expected, the niobium containing alloys show a better oxidation performance compared to commercially pure titanium and the titanium-vanadium alloys. The oxide layer consisted of TiO2 and Ti2O3. Depending of the niobium content, a niobium-rich layer developed below the metal-oxide-interface minimising oxygen diffusion into the titanium matrix. Based on these results, the minimal niobium content needed for improved oxidation resistance was identified so that alloys of technical relevance can now be developed.

Jan 1, 2014

By G. A. Bezuidenhout, J. P. T. Kapusta, D. K. Chibwe

"Peirce-Smith converters (PSCs) are extensively used in the copper, nickel, and platinum group metals industries. The typical converting operation involves lateral purging of air into molten matte through a bank of tuyeres. This blowing operation occurs at low pressure from the blowers, resulting in a bubbling regime that is considered inefficient from both a process and an energy utilization perspective. Inherent drawbacks also include recurrent tuyere blockage, tuyere punching, and low oxygen efficiency.Western Platinum embarked on a full-scale industrial evaluation of generating a jetting regime by using sonic injection. Prior to industrialscale tests, a numerical assessment to ascertain the feasibility of implementing sonic injection into a PSC was conducted. The work included flow characterization at high-pressure injection achieving sonic velocity at the tuyere exit. The 2D and 3D simulations of the three-phase system were carried out using the volume of fluid method together with the RKE turbulence model to account for the multiphase and turbulent nature of the flow.This paper discusses the key findings in understanding plume extension, velocity distribution, shear wall stress analysis, and phase distribution characteristics in the system. Plant trials are also discussed with reference to the commercial aspects of a full-scale implementation of sonic injection in the smelter."

Jan 1, 2015

By A. Vien, B. C. Flintoff, R. P. Edwards

"This paper provides a critical review of the development and application of advanced controls in mineral processing at the industrial level. These algorithms can be sub-divided into four broad categories: Kalman filter, self-tuning, extended horizon, and knowledge based or expert systems. Applications from each category are described outlining the benefits derived, the relative advantages of that particular controller, and potential limitations of the controller which may inhibit their more widespread application. The paper will conclude with a description of control algorithms which are currently in the rudimentary design stage, but may hold tremendous potential for mineral processing control systems in the next decade. INTRODUCTIONThe Canadian mining industry has a large installed milling base and many plants are run with manual or low level automatic process control. The competitive pressures imposed by the market will not allow these operations to ignore the significant increase in efficiency that can be achieved through the effective application of advanced process control. These improvements will come in the form of better quality, higher productivity and reduced costs.There have been quite a number of reports of successful applications of advanced control in mineral processing applications. As this trend continues, and more of the work is documented, the technology will be more effectively transferred to process and control engineers. It is the authors' opinion that the most difficult problems facing process control are not really technical in nature. Rather, they lie more in process control education. This extends from management, through engineering to the operators.The purpose of this paper is to provide a tutorial type overview of some of the more frequently encountered advanced control algorithms. The assumption is that the reader has a superficial knowledge of this technology. In the discussions which follow, several techniques are explored within the framework of simple process examples. Industrial examples are cited for each and an evaluation of the expected longer term potential is given."

Jan 1, 1992

By Salinger, Herbert

WITH the large amount of metallurgical re- search work now being done and the constant effort of the engineer to effect economies of operation, I think it is a safe prediction that the next few years will see a great change in the handling of mine products. The well-managed mine, with sufficient ore reserves to warrant the necessary plants, will increasingly call upon the metallurgist and chemist for the solution of its problems. Shipping sorted ore or concentrate to the nearest smelter will not be the course followed. From ore to metal, or at least to a product directly salable to the consumer, will be the practice followed. As a consequence, mine managers will be increasingly interested in metal trade problems. By metal trade I mean the buying, selling, shipping, handling, and all the practices, forms and customs that go to make up the trade.

Jan 1, 1928

By Fred D. Fox

Introduction Abandoned mill tailings deposits can be found throughout the northern Black Hills of South Dakota, indicative of mining activities that originated during the great gold rush days of 1875. The Refuse Act of 1899 attempted to regulate the deposit of debris from mines and stamp works. But, in most cases, huge volumes of mine and milling wastes were disposed of in ways no longer considered environmentally acceptable. Restoration of gold mill tailings deposits is a relatively new practice to the Black Hills area. This discussion will present an overview of the environmental setting, environmental problems associated with past tailings disposal practices, practices being implemented to solve these problems, and prospects related to present the future tailings disposal practices. Environmental Setting An understanding of climatic characteristics, geology, surface and ground water hydrology conditions, and the physical and chemical characteristics of selected mill tailings deposits will aid in understanding environmental problems associated with tailings disposal and restoration. Climate The Black Hills region is in the middle latitudes, which have a

Jan 11, 1984