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By J. Gardner Brooks, Sidney Sigel, Irvin R. Kramer

In 1942 Grossmannl proposed that the hardenability of a steel may be calculated from its chemical composition by considering the base hardenability associated with its carbon content and grain size and multiplying this base by factors for each element present. Since Grossmann's original publication, several investigaton2-6 have reexamined the multiplying factors for the individual elements and in general have found that the multiplying principle is valid. However, some of the individual factor curves developed have been in poor agreement. Inasmuch as the carbon-factor curve obtained by Grossmann was dependent Lipon the factors for all the other alloying elements present in the steel, it logically followed that his results were in need of correction in the light of the new data available for manganese, silicon, and the other alloying elements. Furthermore, in order to avoid the possibility that errors in the manganese, silicon, or other curves might influence the carbon-factor curve, investigation of iron-carbon alloys containing little or no manganese and silicon was necessary. That the effect of carbon on hardenability was greater than indicated by Grossmann is shown by a comparison of the diameters of completely hardened rounds of iron-carbon alloys with the ideal critical diameter calculated from Grossmann's factors. These alloys have a greater hardenability in a finite quench than predicted by Grossmann's factors for an infinite quench (Table I). Among the other important variables that were in need of further investigation were the effect of deoxidation practice on the grain-size correction curves and the effect of stable carbide-forming elements on the depth of hardening. Most Of the work by Kramer, Hafner, and Toleman4 was done on silicon-killed steels. It was not known whether Gross-mann's grain-size correction curves, determined on aluminum-killed steels, was valid when applied to steels with different deoxidation practice. More data on the

Jan 1, 1947

The Industrial Minerals Milling Section of the Mineral Processing Division has been engaged for the past three years in a study of the separation of minerals, by means of electronic sorting equipment, on the basis of their colour. Considerable knowledge of the subject has been built up. Because the object of this study is application as a means of beneficiation, a number of examples of the separations achieved are presented. Introduction T 0 the mineral collector, the colour of a mineral may be pleasing, even fascinating; to the mineralogist, student or professional, it may also be practical. It serves, to some extent, as a distinguishing feature in many minerals, and helps to fix with reasonable accuracy the identity of a few. It may now become a useful tool of the mineral dresser. The idea of using a difference in colour as a means of separation of one mineral from another is not new. Hand sorting dates back to ancient time. However, the means by which this can be done mechanically was developed only during the past decade. As far as the Mineral Processing Division is concerned, interest dates from March, 1960, when the following item was observed in the

Jan 1, 1965

By Ajit Kumar Jaiswal

"Electric Arc Furnace (EAF) being a power-intensive equipment, EAF based industries are highly dependent on scarce electric energy. This is the reason Government of India is highly concerned about this and laid emphasis on the conservation of electric energy.This paper highlights factors contributing to reduction in specific electric energy consumption in EAF and suggests measures not only for power saving, but also for productivity improvement. To name a few, these are proper sealing of furnace, introduction of oxy-fuel burners, foamy slag practice, increased usage of hot metal/DRI, post-combustion of CO gas for preheating of scrap, improved selection & design criteria of electrics, power demand management, and process automation. Few cases also have been cited, where the above measures have helped in reaping significant benefits.IntroductionFor a long time, Government of India had focused on increase in energy supply, in particular, through electricity generation. Now the emphasis of Government of India has shifted from electricity generation to its conservation for following two reasons:??Power plants have become very cost-intensive??By saving energy, more of it can be delivered at lower cost to the consumersPower generating units, transmission & distribution agencies as well as consumers all have roles to play in the area of energy conservation. By energy conservation, we mean curtailing energy requirement by reducing energy wastages and taking up measures to improve energy efficiency of electric equipment/appliances. In almost all cases, this would be economically beneficial.India’s cost-effective energy conservation potential has been estimated by the Planning Commission at 23 per cent of total commercial energy generated ?1?. A national movement for energy conservation can significantly reduce the need for fresh investment in energy supply systems in coming years. It is imperative that we make all-out effort to realize this potential. Whether a household or a factory, a small shop or a large commercial building, a farmer or an office worker, every user can and must make this effort for his own benefit and for the nation’s benefit as well."

Jan 1, 2009

By W. E. Pittman

The Bureau of Mines, as part of its Health and Safety Technology Program, is conducting research on the use of ground penetrating radar (GPR) for mine hazard detection. GPR offers a possibility of mapping immediate below-surface geologic conditions, including faulting and other anomalies, thereby exposing potential safety hazards to miners. This report summarizes a literature review of the current status of GPR research in and outside the Bureau.

Jan 1, 1984

By H. E. Searle, Robert J. McKay, O. B. J. Fraser

The practical study of corrosion requires consideration of its economic aspects. It must be based on sound scientific principles, but it should be borne in mind that probably the most important object of a corrosion test is to determine what metal in corrosion-resisting construction will produce the greatest operating profit. Thus the corrosion test must be directly connected with money values or it is not a practical corrosion test. This, perhaps unusual, connection between corrosion and economics is partially due to the fact that corrosion deals only with the time factor or duration of equipment, and it is almost the only test which deals with this feature. In these statements a departure is made from the academic definition of the word corrosion and it is done deliberately. The use of the term corrosion is unusual. It is as though we spoke of a tensile test as a "breaking" test. We are not interested primarily in the break but in the strength of the metal. There is no English word which expresses our main interest in corrosion-testing, but let us have clearly in mind that we make corrosion tests to prevent corrosion. Our real interest is in this corrosion-prevention, not in the corrosion. Previous to 1922, it was common comment that "it is impossible to determine the course of corrosion by laboratory testing.'' This statement was true at that time in that the technique of laboratory testing for corrosion resistance was so vague that tests in the laboratory gave untrue results almost as often as true ones. This was so, even in the simple case of determining which one of two metals better resists a given solution. While this is no longer true the number of misleading "corrosion tests" still being ground out by laboratories is too large in the light of our present knowledge. There are two important features of corrosion testing whose neglect is a large contributing factor to misleading results: (1) The economic relations of the corrosion tests to other tests; (2) testing technique. Regarding economic relations J. F. Thompson l has said: "The use of any particular metal is rarely based upon the sole property of resistance to corrosion. In fact, I should like to venture the assertion

Jan 1, 1929

By Robert J. McKay, O. B. J. Fraser, H. E. Searle

The practical study of corrosion requires consideration of its economic aspects. It must be based on sound scientific principles, but it should be borne in mind that probably the most important object of a corrosion test is to determine what metal in corrosion-resisting construction will produce the greatest operating profit. Thus the corrosion test must be directly connected with money values or it is not a practical corrosion test. This, perhaps unusual, connection between corrosion and economics is partially due to the fact that corrosion deals only with the time factor or duration of equipment, and it is almost the only test which deals with this feature. In these statements a departure is made from the academic definition of the word corrosion and it is done deliberately. The use of the term corrosion is unusual. It is as though we spoke of a tensile test as a "breaking" test. We are not interested primarily in the break but in the strength of the metal. There is no English word which expresses our main interest in corrosion-testing, but let us have clearly in mind that we make corrosion tests to prevent corrosion. Our real interest is in this corrosion-prevention, not in the corrosion. Previous to 1922, it was common comment that "it is impossible to determine the course of corrosion by laboratory testing.'' This statement was true at that time in that the technique of laboratory testing for corrosion resistance was so vague that tests in the laboratory gave untrue results almost as often as true ones. This was so, even in the simple case of determining which one of two metals better resists a given solution. While this is no longer true the number of misleading "corrosion tests" still being ground out by laboratories is too large in the light of our present knowledge. There are two important features of corrosion testing whose neglect is a large contributing factor to misleading results: (1) The economic relations of the corrosion tests to other tests; (2) testing technique. Regarding economic relations J. F. Thompson l has said: "The use of any particular metal is rarely based upon the sole property of resistance to corrosion. In fact, I should like to venture the assertion

Jan 1, 1929

By Davey Bickford, Johan Hawinkel

Blasting and the use of civil explosives are a critical step in the mining process. Good decisions provide significant downstream benefits and create a safe and sustainable working environment, while poor decision making and judgement can have catastrophic consequences on workers safety, critical infrastructure or the security of the general public. An ever-tightening regulatory framework increasingly exposes manufacturers, transport companies and mining companies to the consequences of breaches resulting from erroneous or ill-informed decisions. In this context, new capabilities are required providing all actors in the explosive supply chain with tools to make better informed decisions allowing the individual to own up to his or her decision. Additionally, the traditional risk-control approach in the explosive supply chain up until usage and waste elimination, through administrative control procedures and processes, is becoming increasingly inadequate. In this era of digitalisation and automation, technology will play a pivotal role in ensuring safety and security in storage, transport and usage of civil explosives using the latest advances in electronics, communication technology and information technology. This paper explores the journey through time of technology in the civil explosives market to provide testing, measurement, analysis and control tools. This ultimately leads to better decision-making, ensures full accountability of the decision maker and uses the same technology to review decisions for process improvement, in the settlement of disputes or for the investigation of incidents. Additionally, the paper discusses the application and integration of electronic and digital technology in explosives and initiation systems as engineering controls for blasting associated risks. Finally, this paper reviews two practical cases of technology integration for risk management and improved decision making; the use of integrated GPS technology in initiation systems as an engineering control in the blast evacuation process and the use of RFID technology in explosive tracking from cradle to grave.

By J. C. Yannopoulos

The quest for a continuous copper smelting and converting process, which has been going on for a long time, has not as yet reached its objective. The most recent efforts for the development of a continuous copper?making process started about two decades ago. Among the contending proposed processes, four have been piloted and three of them are currently in operation: the WORCRA process., the NORANDA process, the MITSUBISHI process, the OUTOKUMPU process. The WORCRA process, after some long pilot plant tests, failed to develop as an industrial process: The NORANDA process, as currently operating, is a smelting process and not a continuous copper?making reactor as initially conceived. The MITSUBISHI, although the only continuous process, has not been widely accepted. The OUTOKUMPU process can be applied only to a low iron concentrate feed and co?produces blister and high in copper slag. The thermodynamics of these "continuous" systems and the practical problems of their industrial application are reviewed and discussed. The achievement of efficient and inexpensive environmental control should' be the primary objective of any new process development. A review of the environmental problems of the copper industry indicates that the quest for a continuous smelting and converting furnace should be intensified.

Jan 1, 1983

By Warren H. Westphal

For mining and exploration, and indeed the entire mineral industry, the first century of AIME has ended with far more problems than it began. Paradoxically, most of these problems have arisen not because, the industry has been unsuccessful, but rather because it has succeeded too well. Whatever the public demand for minerals over the past 100 years, it has somehow been met-and met at a price well within the public's ability to pay for the products. But as AIME moves into its second century, the past successes of mining and exploration are beginning to levy a tax on the future. Prospectors have already found most of the rich and ready ores, and miners have dug them out. New mineral assets grow progressively harder to come by, and as they do, the need for them grows inversely more pressing. How and where and at what cost can adequate supplies be found? How and at what cost can they be mined from heretofore inaccessible recesses deep underground and under the seas-or from vast surface tonnages containing only minor values? And once they are found or won, how can these assets be husbanded for generations to come? How also can they be extracted without injury to the land, air and water on which we and our successors must depend? And what constructive use can be made of the incidental materials now treated merely as wastes-sometimes at great expense?

Jan 1, 1971

By E. Fiset, T. Hennebel, F. Verbruggen, A. Prévoteau, K. Rabaey

Arsenic (As), bismuth (Bi) and antimony (Sb) are known to affect the quality of copper deposits in copper electrowinning operations. The codeposition of As was previously believed to occur only at current densities far exceeding the range of typical current densities for copper electrowinning. In this study, we investigate the copper electrodeposition on different pretreated stainless steel (SS) substrates from bleed electrolyte in galvanostatic mode at –45 mA/cm². Scanning electron microscopy (SEM) micrographs illustrate that during the initial phases of copper nucleation and growth, the current density was locally increased due to the pretreatments. It was reasoned that the codepostion of As could possibly occur in normal electrowinning conditions, but the risk can be substantially reduced by good SS substrate handling and maintenance practices. INTRODUCTION The presence of As, Bi and Sb is known to have a deleterious effect on the copper cathode quality in copper electrowinnings (Hiskey & Maeda, 2003; Hoffmann, 2004; Xiao, Cao, Shen, & Volinsky, 2012; Xiao, Cao, Mao, Shen, & Ren, 2014; Jafari et al., 2017). They are known to influence both the chemical and physical quality of the copper as they can contaminate the copper (Jafari et al., 2017) and affect the copper deposit structure (Hiskey & Maeda, 2003; Kim, Kim, & Chung, 2009), which contributes to a degraded market value of the copper (Tuddenham, 1984). The incorporation mechanisms of these impurities are believed to occur mainly through slime inclusion (F. Xiao et al, 2012) and electrolyte inclusion (Hiskey & Maeda, 2003). Other studies suggested that codeposition of these impurities is possible by their standard reduction potential being close to the one of copper (Xiao et al, 2014). Hiskey and Maeda (2003) investigated the copper electrodeposition on a copper electrode substrate in Cu electrolytes with a Cu, H2SO4, As, Bi, Sb composition representative for commercial copper tankhouses. The combination of voltammographic techniques and Auger electron spectroscopy showed that As was the first impurity to be electrodeposited from this electrolyte, yet at potentials where the limiting current density of the copper electrodeposition reaction is exceeded. The copper tankhouses usually operate at a current density ratio of 0.3 to the limiting current density in order to achieve tolerable copper quality deposits. The codeposition of As could be considered impossible in this current density condition. However, it is known that during the initial phases of electrodeposition on foreign substrates, a substantial part of the reaction proceeds by growth of individual nuclei where the current density is locally high and diffusion limited (Radisic, Ross, & Searson, 2006). Furthermore, it was observed that copper nucleation on TiO substrates occurred preferentially in the scratched oxide free areas which could serve as parts with high localized current densities (Chang, Choe, & Lee, 2005).

Jan 1, 2019

By R. C. Dunne

As ore grades of existing and new ore deposits continue to decrease there is ever increasing pressure to decrease operating costs to maintain profitabitabitiy at existing mine sites and for new projects. The accepted solution to this dilemma in most cases is to increase treatment rate, leading to a coarser grind, at the expense of marginal decreases in recovery. The recovery loss is usually associated with losses of liberated and composite coarse material. This paper will review the practice of coarse particle flotation, including the reagent chemistry, cell hydrodynamics, froth stability, entrainment and flotation cell design, all parameters important to the recovery of coarse liberated and composite particles. This will provide a better understanding of opportunities to improve the recovery of coarse particles. Some examples will be provided.

Sep 1, 2012

By Braithwaite J. C

A brief summary is given of the applications of geochemistry on two areas in North West Nelson. It has been found to be an effective method for reconnaissance prospecting. Its particular advantage lies in areas which due to thick bush cover or ru

Jan 1, 1980

By L. A. Jordan, D. van Vuuren

A two-dimensional finite difference model has been developed to describe the reduction of kilogram quantities of dehydrated phosphogypsum. The model’s scope has been limited to focus on the heat transfer and reactions that occur within a mass of material contained in a vessel inside a furnace rather than also including the effects of heat transfer to the vessel. Changes in the heat transfer properties (k, ρ, and Cp) are incorporated as the composition of the mass changes as the chemical reactions progress. The model is validated against experimental data, with samples heated to 1000°C at 3°C min−1 while purging with nitrogen gas. A sensitivity analysis of model predictions to the pre-exponential factor of the reaction rate constant of the main chemical reaction and the thermal conductivity of the powder bed indicated that, at the envisaged process conditions, the behaviour of the system depends much more on the rate of heat transfer than on the rate of the chemical reaction. The model demonstrated a significant increase in accuracy when the thermal conductivity was modelled to increase linearly with temperature compared to assuming a constant value.

Oct 1, 2022

By A. U. Christensen

THERMODYNAMIC data for many of the common interoxidic compounds are seriously lacking, and appraisal of possible ceramic or metallurgical applications depends upon dubious estimates. In particular, high-temperature heat-content estimates may be invalid because of unknown phase-transformations. This paper reports experimental heat-content values above 298.15° K. for five interoxidic compounds-the aluminates of lithium and sodium (LiAlO2 and NaAlO2), the ferrites of lithium and sodium (LiFeO2 and NaFeO2), and lithium titanate (Li2TiO3), as obtained by the Bureau of Mines. Sodium aluminate, sodium ferrite, and lithium titanate were found to have previously unknown transformations in the crystalline state. The heats and temperatures of these transformations were evaluated as were also the heats and temperatures of fusion of sodium ferrite and lithium titanate. The heat-content results are assembled in both tabular and algebraic-equation form for use in conducting thermodynamic calculations at temperatures in the range 298°-2,000° K.

Jan 1, 1960

By J. H. Gasper

A cost analysis for two alternative contour mining methods is performed to compare their results. The methods evaluated are: 1) Front-End Loader/Truck Haulback and 2) Scraper Haulback. Before performing these analyses, output requirements and equipment needs are found based on integrating geometric limitations with material properties. The final geometric design establishes limits on clearances, congestion problems and grades (with associated running surface materials). All calculations are kept practical, with assumptions clearly stated. The cost analysis is a unique, easily utilized compilation of several different approaches incorporating cost engineering principles. The strengths of each are welded into a cohesive entity once again aimed at practical application. The results are presented in tabular form.

Jan 1, 1992

Morning Star Gold aims to enter the ranks of Australia's gold producers, revitalising the Eastern Victorian Goldfi elds in the second half of 2010 - the fi rst gold production in around 50 years from the Morning Star Gold mine, which was once Australia's largest under WMC. This presentation will outline the redevelopment of the Morning Star Gold Mine from exploration to production. Morning Star Gold NL's (MCO) key project area is centred at the historic mining town of Woods Point and nearby Matlock (to the southeast) and Gaffney's Creek (to the northwest), all of which are located in the lower part of the Victorian Alps roughly 60 kms south of Mansfield. Morning Star has literally numerous historic mines and gold bearing 'dykes' on its tenements, many with a rich production history of high-grade gold from quartz reefs and alluvial sources. The area encompassing the Woods Point goldfi eld and the multiple high-grade gold bearing dyke structures located north towards Jamieson and south towards Walhalla formed one of the most significant mining fields in Australian history. Historical gold production was at least 155 t or around six million ounces of over a century of mining with an average production grade exceeding 27 g per tonne. The bulk of this recorded production came from just a handful of mines and of those only three were mined to any great depth. One of the key historical production hubs in this area was the famous 'Morning Star' mine, which is situated adjacent to Woods Point township. The Morning Star mine produced almost one million ounces at 27 grams per tonne, operating fairly continuously between 1861 and 1959 with a break after Jan 1939 due to the devastating 'Black Friday' bush fi res across eastern Victoria. During the early 1940s, the Morning Star was Australia's biggest gold mine. The Morning Star mine along with Walhalla ensured that this goldfield was third behind Bendigo and Ballarat as Victoria's biggest hardrock gold production centre. Morning Star Gold has rebuilt its 100 per cent owned 'Morning Star' mine with a view to producing gold in the second half of 2010. Morning Star is exploring its regional dykes in order to estimate an overall gold endowment and rank local production sources to feed its proposed mill at the Morning Star mine site. Key initial targets (all within 11 kms of the Morning Star mine) are the Waverly, All Nations, Rose of Denmark, Hunts, Wallaby and Loch Fyne dykes, all of which historically produced high grade gold, much of it gained from only shallow workings above the water table in the weathered zone of rocks. Historically the Morning Star mine was developed over 24 levels to a depth of 940 m via one large vertical shaft and a smaller, deeper inclined shaft at the 1900 feet level underground. At present MCO has dewatered and completely refurbished all infrastructure to the ten level (~310 m below surface). MCO knows there are a number of substantially under-explored and undeveloped or partially developed but not stoped areas within the Morning Star mine. As a result, MCO has been carrying out extensive channel sampling and an underground diamond drilling program targeting areas of the mine that were largely unexplored and undeveloped by the last operators of the mine - Western Mining Corp Ltd (Gold Mines of Australia). Four thousand, fi ve hundred pages of archival WMC records have helped the cause significantly. The shaft refurbishment and reconstruction stage is complete. This has been a program that originally commenced back in 1993 and has cost around $22 M. This refurbishment paved the way for the extensive underground resource focused diamond drilling program, which MCO completed in 2008 with two company-owned and operated drill rigs from drill cuddies on level 9 (900 feet underground) of the mine. This drilling, which encountered some stunning grades intersections and multiple visible gold hits, has outlined further production opportunities including 0.4 m @ 1392 g/t Au (MS 410). Metallurgical testing conducted by Gekko Systems of samples obtained from the exploration program found gravity concentration and a leach circuit gave recoveries of ~95 per cent to 99 per cent, or ~92 per cent from gravity alone at a coarse crush (300 ¦m). Currently, the plan is to use gravity to fi rstly produce dore bars on-site from the free milling gold and secondly a saleable concentrate for CIL processing off-site. A purpose built 10 t/h (~80 000 t/a) gravity treatment plant was subsequently ordered from Gekko and is expected to be installed onsite and commissioned in the Q3 2010. The plant features fi ne crushing with a vertical shaft impactor, followed by gold concentration by inline pressure jig, inline spinner and Wilfley table. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Aug 1, 2010

By Jr. Frost

Helium used as a tracer gas in petroleum reservoirs continues to show great promise as a new tool for the oil and gas industry, according to tests conducted jointly by the Bureau of Nines and The Pure Oil Co. in-the Cabin Creek field, Boone and Kanawha Counties, W. Va. Helium, when used as a, tracer gas, is mixed with natural gas being injected into a reservoir for secondary recovery of oil, recycling, pressure-maintenance, or other purposes. Three separate experimental helium tracer-gas tests were run in the Cabin Creek, W. Va., field, wherein helium was added as a tracer to the natural gas that was being injected into the oil-bearing Berea sandstone. The results obtained in each test permitted determining the direction and rate of travel of the injected gas, calculating the volume of injected gas in the gas produced at the various wells, and determining the nature of the transition from natural gas to injected gas during a gas-injection program. Data were obtained on the effects obtained from waves of injected gab containing 1 percent and containing 5 percent helium and from a wave of essentially pure helium injected into the formation.

Jan 1, 1950

By A. W. Deurbrouck

The Bureau of Mines analyzed 13 samples collected from three Randolph County coalbeds. The Peerless and Sewell bed samples were generally of metallurgical quality as received from the mines or could be easily upgraded. How-ever, the Lower Kittanning coa1bed samples proved to be quite inimical to upgrading to metallurgical quality.

Jan 1, 1966

By David Penswick

Despite anecdotal evidence to the contrary, the mining industry is not in decline. Rather, the world?s largest mining companies are among the most consistently profitable companies in any industry. In many cases, profitable mining companies have been built around a few large scale, long life mines. These criteria for success ? size and long life ? have led to the current preference for deposits that can be exploited using open pit methods. However, developments in the science of block caving have resulted in this mining method achieving costs and productivities that are competitive with the largest open pits, while achieving widespread applicability. One implication of the low costs and widespread applicability of block caving is that some current open pits are possibly too deep.

May 1, 2003

By Magnus Ek

After the installation of three new converters as part of the recent expansion of the Rönnskär smelter completed in 2000 work continues to further improve the converter operation. The converter upgrade led to an increase in blister copper taps from 150 tons per batch to more than 300 tons. The total cathode copper production increased from 130,000 tons in 1999 to 230,000 tons in 2001, the first year in full production. In recent years focus has been to improve operating practise, maximize the blowing time, extend the converter campaigns hence to reduce the specific brick consumption and improve the converter slag composition.

Jan 1, 2005