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By Hongqiang Wang, Qingliang Wang, Eming Hu, Zhiwu Lei, Fang Hu, Rui Zhang, Wei Hou

Pyrite, a mineral associated with uranium ore, is closely related to uranium leaching. In this study, Ozone micro-nano bubbles (OMNBs), as an environmentally friendly advanced oxidation technology, were used for the first time to oxidize pyrite under experimental conditions to improve the leaching rate of uranium. A laboratory-scale agitation leaching experiment of pyrite was carried out with a pH of 1.0–3.0, gas flow of 1–3 L/min, ozone generation rate of 0.55–2.22 mg/s, and pyrite concentration of 0.1–5.0 g/L for 1 h. By adding three different co-oxidant: Mn(II), Mn(IV), and Fe(III), it was found that only Mn(IV) increased the oxidation rate of pyrite by 21.7%. The results of the scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) show that the formation of Fe(III)-O film on the surface of the ore suppresses the oxidation rate of pyrite to a certain extent. Pyrite can be rapidly oxidized up to 57.6% by OMNBs, which is beneficial to uranium leaching. This method is expected to be used for in situ acid leaching of uranium with OMNBs injected into the ground.

Jan 3, 2022

By J P. Sykes, T C. McCuaig, M Jessell, A Trench

The election of Donald Trump and the Brexit referendum herald a shift towards a tighter definition of economic value, at the expense of the broader value concept of sustainable development; as well as a rise of protectionism, reversing a long-term trend of globalisation. However, the situation is complex, especially over the longer term in which mine project development and exploration operates. The minerals sector should proceed with caution. A greater focus on the local impacts of mining may be strategically beneficial, not only to mitigate against a potential protectionist future, but also because sustainable development has become more ‘localist’ via the concept of ‘social licence to operate’, whilst globalisation also seems to provoke increased ‘localist’ sentiments (known as ‘glocalism’). Localist strategies, therefore, seem a good hedge against multiple political futures. By contrast, moving away from sustainable development appears strategically riskier. Not only are ‘unsustainable’ activities, such as pollution and civil rights infringements harder to reverse, but a movement towards a more sustainable global economy may already be predetermined, even if the journey there may seem oblique. It appears that the increased economic development that is coveted globally is intrinsically linked to a rise in environmental and social consciousness.CITATION:Sykes, J P, Trench, A, McCuaig, T C and Jessell, M, 2017. Charles Dickens on the (potentially) changing role of globalisation and sustainability in the long-term future of mining and exploration, in Proceedings Tenth International Mining Geology Conference 2017, pp 239–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By A. J. Monhemius

This paper reviews the history of modern iron-control processes in hydrometallurgy. Attention is paid to processes developed in the electrolytic zinc industry for removal of iron from zinc sulfate leach liquors and the problems faced by the industry in the safe disposal of the iron residues produced by these processes. Past lessons learned are projected onto current efforts to develop hydrometallurgical processes for treatment of copper sulfide concentrates. It is argued that any attempt to create a \u201chydrometallurgical copper smelter\u201d will fail, unless methods are developed that can recover iron in a form that can be directly used by the steel or pigment industries.

Jan 1, 2017

By E. A. Barrett

The U.S. Bureau of Mines (USBM) conducted experiments to determine if training using a latent-image, three-dimensional (3-D) slide simulation exercise improved miners' ability to recognize roof and rib hazards. The effectiveness of this innovative type of classroom training was investigated by measuring workers' performance on a hazard recognition task. The study was unique in that hazard recognition skills were assessed in the workplace using actual coal mine roof and rib hazards. Results showed that training with a latent-image, 3-D slide simulation exercise significantly improved each subject's performance on the in-mine hazard recognition task. Further, the USBM researchers concluded that transfer of learning from the classroom to the workplace occurred.

Jan 1, 2010

By Feridon Ghadimi, Saeed Mojeddifar, Massume Khavari

Separation of geochemical anomalies from background is an important and essential issue in the exploration of mineral deposits. Statistical methods are used to separation of anomaly from background. Fractal/multifractal and singularity methods are very suitable for the separation of weak anomalies. For interpolation, various methods could be used such as most distance-weighting methods, kriging, spline interpolation, interpolating polynomials, and finite difference methods. This paper addressed application of multifractal techniques together with finite difference procedure to detect the anomalous regions. Fractal models such as concentration–area, spectrum–area, and singularity index model were selected to identify Pb–Zn anomalies. In this research, 170 samples from 33 boreholes were taken in the Haft-Savaran area and analyzed for determination of Pb–Zn anomaly. Singularity method was a suitable method for separating Pb and Zn anomalies. Also, the results showed that the geochemical anomaly has occurred along NE–SW trend and is consistent with the sulfide mineralization process and the faults of the region.

May 18, 2020

By T. Dlokweni, M. Bester, C. Koegelenberg, I. Basson

Certain degrees of safety, economic, and financial risk are implicit in any mining operation. At Thabazimbi Mine, slope stability was one of the major sources of risk, largely due to data uncertainties. Consequently, a risk-based approach in slope design was followed. On 6 June 2015, a slope failure occurred in Thabazimbi Mine’s Kumba pit, involving approximately 65 million tonnes of rock failing into the pit and the valley below. Although the failed mass moved rapidly and resulted in a run-out distance of approximately 900 m, controls had been put in place to successfully evacuate all personnel. Risk assessment during the onset of failure supported the decision to not compromise the safety of personnel in any way, leading to unavoidable equipment loss. This contribution presents the failure as a case study in the context of a risk-based approach to slope design as well as the importance of implementing geotechnical controls to effectively manage slope instability risk. Furthermore, a comprehensive back-analysis was performed, on a fully constrained 3D model, utilising 3DEC software, to gain insights into the failure mechanism. In conclusion, lessons from the Thabazimbi slope failure are valuable as they demonstrate the importance of following a risk-based approach in slope design to effectively manage safety and financial risk in open pit mines.

Sep 1, 2025

By E Rubio, N Morales

A common practice in the mining industry is to decompose the planning process into different tasks, so the overall process and specific schedules can be constructed easily. Nevertheless, currently there are some adverse effects, such as not capturing the real value of a project by not taking into account the construction of several underground drifts and general infrastructure. Then the common practice is to compute mining sequence and cut-off grade profiles over the life of the mine without constitutively integrating the development schedule as a means to measure the constructability of a given mine design and sequence. Thus, the investigation summarised in this paper shows a novel, integrative way of treating an underground mine sequence and production schedule while considering drift development scheduling. Moreover, it is thought that, because of this original model, the whole underground production scheduling exercise must concentrate on combining the development and the production scheduling to compute a robust and a feasible production schedule.In order to quantify the effect of the conventional way of viewing the planning, the concept of the building information model (BIM) needs to be used, which was postulated by Charles Eastman and has been used extensively since the late 1970s. BIM takes other aspects of a project into account, considering at the same time the spatial relationships, quantities and properties of building components, but especially some kind of model visualisation, which is the advantage to be incorporated. This paper presents the basis for an optimisation model that allows for defining the sequence of the mining development so that the production plan can be achieved. For this, the model considers the space dimensions, time, pattern or strategy, cost or benefit, precedence and resources available. Tests were performed considering a block caving and sublevel open stoping method. Finally these tests showed the main conclusion, that production sequence changes when the building capacity is considered.

Sep 26, 2011

By Vard H. Johnson

"In contrast with the well-publicized Pittsburgh coal, and the Everglades of Florida, most coal-forming swamps of Cretaceous time in western North America occupied relatively limited areas. They formed in areas of irregular subsidence, bounded by the changing levee systems of meandering streams. Coke quality is determined by the physical and chemical behaviour of the vitrain during thermal decomposition. Vitrain is at least in part a colloidal substance, originally containing large proportions of water; its formation and survival depend on maintaining a shallow cover of stagnant water up to the time of burial. Heat from swamp fires or subaerial dyhydration could destroy it or impair its quality. Observed patterns suggest that the metamorphism is almost entirely thermal, and that there is little relation to tectonic stresses, or loading. These coals had probably achieved essentially their present rank prior to deformation. Evidence of frictional heating along the thrust planes is minimal or absent. Normally, coal beds are aquifers. Oxygen carried into the subsurface becomes available and reacts with the vitrain to destroy its natural thermoplastic properties. The tolerance of oxygen without loss of thermoplasticity is inversely related to the volatile content. Significant lateral variations of coal thickness are common and sometimes occur in short distances. In deformed areas these thickness changes are more commonly due to differential tectonic stress rather than to original thicknesses of coal. Locally, coal is known to have flowed into cavities, or fractures. These principals are discussed in relation to coal deposits of western Alberta and eastern British Columbia."

Jan 1, 1972

By Sathit Tandanand

This Bureau of Mines report describes the method of obtaining a strength index for rock drillability, particularly for percussion drills. The original Protodyakonov method has been slightly modified, essentially to eliminate uncertainties in the measurement of the volume of fines, and to avoid conjecture in selecting the representative value as the strength coefficient. A theoretical consideration of the relevant parameters in the method was extended from a comminution theory, and hence the meaningful value was obtained experimentally by plotting the ratio of the number of drops and the volume of fines against the number of drops. The minimum ratio of the number of drops to the volume of fines in the plot was selected as the coefficient of rock strength. The modified method of obtaining the strength coefficient preserves the original Protodyakonov test apparatus and the merit of simplicity of the test procedure. The modified coefficient of rock strength shows its usefulness in predicting penetration rates with greater reliability than other mechanical properties. Consequently, the drillability curves were drawn using the modified coefficient of rock strength as the parameter for penetration rate prediction in the field.

Jan 1, 1975

By Marcus A. Grossmann

The Institute has established this lectureship to honor the memory of a great American metallurgist, one whose fame has continued long after his passing. As one scientist recently stated it, "All metallurgical texts gradually become outdated and outmoded, except those of the great Henry Marion Howe." It seems fitting, then, that, once every year, we shouId review, in his honor, some aspects of the science in which he was such a distinguished leader, and also discuss any new data that may help to clarify our concepts. It is my privilege, for which indeed I express the deepest appreciation to this Institute, to offer for consideration a few thoughts on the toughness and fracture of hardened steels. Before proceeding to the data, I wish to express my great indebtedness to many associates whose stimulating discussions, generous contributions of data and cooperation in experiments are gratefully acknowledged. (But I wish to absolve them of any blame that may arise from the way in which their discussions and data have been used!) First, Dr. Edgar C. Bain, Vice President, Carnegie-Illinois Steel Corporation, whose amiable but merciless criticisms and always constructive and thoughtful suggestions help unfailingly to guard against pitfalls. Then to associates at Gary Steel Works, especially Mr. H. B. Wishart, Mr. W. K. Smith and Mr. V. Elliott, for great assistance in securing data. Also to Col. C. H. Greenall, Director of Laboratories, Frankford Arsenal, and his metallurgical staff, including Messrs. J. K. Desmond, H. Markus, D. F. Armiento, H. Rosenthal and Henry George, for numerous data and illustrations. Further to Dr. J. R. Low and Dr. M. Asimow, for helpful discussions of effects of states of stress during deformation and rupture, to Mr. J. M. Hodge for discussions and data, to the staff of the U. S. Steel Corporation Research Laboratory for advice and data, and to the Metallurgical Staff at Duquesne Steel Works. The individual acknowledgments will also be found under illustrations. Acknowledgment is also due to Mr. S. C. Snyder for incredibly meticulous scrutiny of manuscript. To all of these, grateful thanks. Introduction The discussion to be offered here will deal with quench-hardened steels only, and may perhaps be considered under three headings: 1. It was found that, when ferrite was precipitated in the (prior austenite) grain boundaries of hardened steel, the notch-bar toughness was much less than in pieces fully hardened. The fracture took place in the ferrite, and the loss in toughness is attributed to the lower cohesive (cleavage) strength of the ferrite, as cornpared with martensite. 2. When notch-bar impact test pieces of quenched and tempered steels were examined as to their mode of fracture, it

Jan 1, 1947

By Marcus A. Grossmann

The Institute has established this lectureship to honor the memory of a great American metallurgist, one whose fame has continued long after his passing. As one scientist recently stated it, "All metallurgical texts gradually become outdated and outmoded, except those of the great Henry Marion Howe." It seems fitting, then, that, once every year, we shouId review, in his honor, some aspects of the science in which he was such a distinguished leader, and also discuss any new data that may help to clarify our concepts. It is my privilege, for which indeed I express the deepest appreciation to this Institute, to offer for consideration a few thoughts on the toughness and fracture of hardened steels. Before proceeding to the data, I wish to express my great indebtedness to many associates whose stimulating discussions, generous contributions of data and cooperation in experiments are gratefully acknowledged. (But I wish to absolve them of any blame that may arise from the way in which their discussions and data have been used!) First, Dr. Edgar C. Bain, Vice President, Carnegie-Illinois Steel Corporation, whose amiable but merciless criticisms and always constructive and thoughtful suggestions help unfailingly to guard against pitfalls. Then to associates at Gary Steel Works, especially Mr. H. B. Wishart, Mr. W. K. Smith and Mr. V. Elliott, for great assistance in securing data. Also to Col. C. H. Greenall, Director of Laboratories, Frankford Arsenal, and his metallurgical staff, including Messrs. J. K. Desmond, H. Markus, D. F. Armiento, H. Rosenthal and Henry George, for numerous data and illustrations. Further to Dr. J. R. Low and Dr. M. Asimow, for helpful discussions of effects of states of stress during deformation and rupture, to Mr. J. M. Hodge for discussions and data, to the staff of the U. S. Steel Corporation Research Laboratory for advice and data, and to the Metallurgical Staff at Duquesne Steel Works. The individual acknowledgments will also be found under illustrations. Acknowledgment is also due to Mr. S. C. Snyder for incredibly meticulous scrutiny of manuscript. To all of these, grateful thanks. Introduction The discussion to be offered here will deal with quench-hardened steels only, and may perhaps be considered under three headings: 1. It was found that, when ferrite was precipitated in the (prior austenite) grain boundaries of hardened steel, the notch-bar toughness was much less than in pieces fully hardened. The fracture took place in the ferrite, and the loss in toughness is attributed to the lower cohesive (cleavage) strength of the ferrite, as cornpared with martensite. 2. When notch-bar impact test pieces of quenched and tempered steels were examined as to their mode of fracture, it

Jan 1, 1947

By A. J. Kraemer

The twenty-fourth of a series of semiannual surveys pertaining to motor gasoline marketed in the United States was made by the Bureau of Mines in August, 1931. The first part of a report giving the results of that survey as they pertain to specification data is given in this paper. A companion report, Part II, is in preparation and will discuss the results of other determinations made on the samples, including octane number ratings on the individual samples (to be made by the Bureau of Standards) and results of the determination of gravity, color, doctor test, and "gum" content by the copper dish method and the Bureau of Mines steam-oven method. The retail price and the tax at the time each sample was taken will also be reported.

Jan 1, 1932

By Jorge Agramonte Bermejo

Dado que el Perú es un pais rico en carbón antracítico y con limitados yacimientos de carbones semicoquizables, la tecnología que predominará para una producción mayoritaria será en relación con el consumo de la antracita en la industria de acero y de otras que le signifiquen ahorro de divisas y petróleo. En ese sentido, el objetivo del texto radica en hacer conocer la potencialidad de los yacimientos, cantidad, calidad de recursos y reservas de los mismos.

Nov 8, 1982

By O. C. Wheeler

In order that the series of reports on oil and gas in Colombia may be complete, the report for the year 1941, which was not available for Volume 160 of the TRANSACTIONS, is given here. The report for 1945 begins on page 4o6.

Jan 1, 1946

By M. J. Sapko

The pressure and flame development of the methane-air-nitrogen system was investigated in the Bureau's l2-foot-diameter sphere to define buoyancy effects and to develop relationships for predicting venting requirements. Pressure rise (?P) is defined as a function of time (t) and nitrogen dilution and is shown to deviate noticeably from the cubic law (?P = kt3), depending upon the period of combustion and the mixture composition. Corresponding flame speed (Sf) and burning velocity (Su) data are given which show that Sf is time dependent and that Na dilution has a greater effect than air dilution in inhibiting the flame propagation. The Su data agree with "accepted" values and are unique in that they are based on much larger flames than those used in other investigations. Downward propagation limits are shown to depend mainly upon buoyant forces, which can affect the burning of even stoichiometric CH4-air systems. Theoretical expressions, based on the mixture burning velocity and expansion ratio, are given for predicting the venting requirements for ignitions of hydrocarbon-air-nitrogen mixtures in spherical or cubical enclosures.

Jan 1, 1976

By R. R. Sayers

Under compuision of the present urgency to implement the President's promise to make the United States the arsenal for the democracies there is a tendency to demand a relaxation of restrictions on hours of labor and to speed up all industrial processes. The pressure is the more insistent with growing realization of the importance of the time factor in the success- ful prosecution of the war effort and the lack of skilled workers due to (2) operation of the draft, lack of an apprentice system in industry, and loss of skill by workers unemployed for long periods during the depression. With "total" war such as it is today the probabilities are that everyone will be required to exert greater effort (in many instances in activities to which they are unaccustomed) for longer periods than ever before has been necessary. The question arises, "What will be the aftereffects as well as the immediate effects on health, safety, and efficiency?" A review of the literature leaves the impression that this question has not been an- swered completely, especially as regards the ultimate effects. Mechanization, speeding up of industrial processes, mass produc- tion, and the small industrial concerns present many problems to indus- trial medicine. Does the tendency to expect the worker to produce at full speed all the time he is on the job decrease the effectiveness of the shorter working hours and cause undue fatigue, loss of efficiency, and increased accident proneness? The answer is important as this condition is likely to be intensified by the exigencies of the present emergency. According to Viteles (1)3, The increased tension under such conditions of work appears to offset the savings in muscular force made pos- sible by the machine. The tension, the speed, the subject- tion to specialization of work and a rhythm uncontrolled by the individual promote fatigue, characterized by a "decrease in the power to work, a decrease in pleasure taken in work, and a decrease in the enjoyment of the hours spent away from work."' The crowding of workers in temporary structures without proper provision for comfort and health may add greatly to the general fatigue factors already present in many industrial establishments. In 1932 Lockhart (2) stated that the production and maintenance of a healthy, satisfied industrial population is the most urgent necessity, involving problems so serious as to constitute a national task too great economically to be relegated to industrial concerns. If this was true in 1932, it must be doubly so today.

Jun 1, 1942

By Haotian Xue

A new process to extracted antimony directly from stibnite concentrate by reductive sulfur-fixation smelting in sodium molten salt has been presented. The influences of sodium salt content and composition, ferric oxide addition, temperature and time was investigated, respectively. The optimum conditions was determined as follows: W????: ??concentrate=40%, W??alt: ????concentrate =88.75%, WFe2O3 :Wconcentrate =55.13%, W??aCl: ????alt=40%, 1123K, 1h. Under above-mentioned optimum conditions, the average direct recovery ratio of antimony can reach 91.48%, and the main chemical composition of obtained crude antimony is Sb 94.31%, Fe 4.436%, Pb 0.502%, Au 0.0236%. In comparison to traditional antimony pyrometallurgical process, the smelting temperature of present process is reduced from 1423~1473K to 1123~1173K. During the smelting operation, SO2 emision can be avoided completely due to sulfur-fixation as FeS. Furthermore , S0 can be obtained when the molten slag is handled by water leaching with conditions of 323K, L/S=5/1, 2h.

Jan 1, 2014

By Alvin Kaufman

Following the gold discoveries of the late 1800's much was written regarding the vast mineral resources of Alaska, and much interest was aroused, and yet over the years little has been done to exploit those resources. Between 1906 and 1935 the Kennecott copper mines of the Copper River region were the keystone of the mineral economy (fig, 1). After the depletion of the Kennecott ore reserves and aided by the statutory rise in the price of gold, the yellow metal became the major mineral commodity. In recent years it has shared the honors with coal and sand and gravel. Although this trend should indicate the development of a stable, diversified mineral industry, yet the trend of production is downward. This report results from a study by the Federal Bureau of Mines to delineate the problems and to forecast the growth of the mineral industries in Alaska. The need for such a blueprint for the future was enhanced by the population explosion in the United States and the consequent eventual need for additional living space, as well as the current interest in new areas, and the necessity to develop reserves of strategic minerals.

Jan 1, 1961

By John H. Nicholls

In this paper, Imperial Oil Limited reports briefly on the drilling by contract rigs of twenty-nine slim holes in the Virden, Smiley, and Souris Valley areas. The investigations showed that slim-hole penetration rates, as a result of careful control of drilling variables, can approach those achieved with 7 7/8-inch bits. It is concluded that slim-hole drilling is acceptable for development or exploratory work. Imperial also reports on the completion techniques and equipment that have been developed on twenty-seven tubingless 2 1/2-inch casing completions. Indications are that the method is economically desirable where excessive gas or water production is not anticipated.

Jan 1, 1958

By AIME AIME

SIR HENRY CORT HAROLD CARPENTER, F. R. S. professor of metallurgy at the Royal School of Mines, was presented with his Honorary Membership certificate in the A.I.M.E. on Oct. 18, at a luncheon in his honor in the Abraham Lincoln room of the Savoy Hotel in London. The presentation luncheon was attended by some thirty distinguished representatives of the academic and industrial British metallurgical world, all friends and acquaintances of Sir Harold. Frank W. Harbord and

Jan 1, 1938