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By SAM A. LEWISOHN

IT is popular today to dramatize in a journalistic spirit, some particular factor among the causes of unemployment. Naturally the time chosen for such emphasis is usually when the factor in question is temporarily a particularly active one. A few months ago, in the unemployment then current, we saw largely the results of a healthy acceleration in changes in processes, greater efficiency, a more intensified use of labor-saving devices, perhaps also a change in products. So we have been hearing a great deal about the influence of mechanization on unemployment, the so-called technological unemployment. Many talk as if this kind of unemployment were a wholly new phenomenon, for- getting that it is a constant process in a growing industrialism, though it sometimes becomes more pronounced. At other times one would think that seasonal unemployment is the only type of unemployment, and then again the fashion changes and we hear .about nothing except cyclical unemployment. Every few years there seems to be a different fashion in labelling the germ supposed to be the cause of unemployment.

Jan 1, 1929

The optimal production of the metals needed by society is best achieved by a close synergy between concentrate production and smelting. For over 75 years commencing in 1923, such a close relationship was enjoyed between the Sullivan Mine in Kimberley, British Columbia and the Trail zinc-lead complex. An effective program of continual change and improvement at the Sullivan concentrator was achieved through a strong entrepreneurial spirit. This spirit was in part maintained through a favourable location in south-eastern British Columbia that resulted in a dynamic local community that has survived the closure of the mine. Innovations to be reviewed include feed forward reagent control, the use of column flotation to zinc and lead cleaning and the application of ultrafine grinding coupled with concentrate dewatering using hyperbaric filter technology.

Jan 1, 2005

By Daniel E. Sullivan

This Bureau of Mines publication examines the potential impact on minerals of the tariff and nontariff agreements that resulted from the Tokyo Round of the Multilateral Trade Negotiations, which were conducted under the auspices of the General Agreement on Tariffs and Trade. These agreements will affect minerals by reducing tariff levels and by changing rules by which they are traded internationally.

Jan 1, 1981

By Anne Lemnitzer

Experimental data are the cornerstone of scientific research, providing empirical evidence to validate hypotheses, test theories, inform decision-making and help develop innovative design and analysis methods. However, beyond traditional empirical validations, experimental data have also become the most crucial component of AI algorithms, measuring the algorithms' effectiveness, and allowing engineers to ensure their reliability and applicability. The DFI "Rock Socket Project," awarded in the spring of 2018 allowed for the indispensable, experimental data-based validation of structural shear magnitudes, which have been hypothesized and discussed for years within the deep foundations community and cautiously approached by many design engineers. The fundamental project idea, i.e., the investi- gation of pile shear magnitudes through experimental research, was sparked during a heated discussion in the October 2016 Drilled Shaft Committee meeting in New York. Should we design for amplified shear at the rock socket of a drilled shaft or is this merely an artifact of the p-y design approach? Data were needed to provide consensus.

Nov 1, 2023

By Frank F. Aplan

Froth flotation has been used to improve the recovery of fine coal, for minimizing the sulfur and ash content of clean coal and for the removal of fine coal from recycled or discharged backwater from coal preparation plants. Though froth flotation and allied processes for ores date from the turn of the century, with the first U.S. commercial application in 1911, coal flotation has been introduced into U.S. practice much more slowly. The first European coal flotation plant was started in 1920, and by 1933 Europe had 60 operating plants while the United States had only one plant, newly commissioned. Over the years there has been a steady increase in coal flotation so that today one-third of the 345 U.S. plants employ the process. This report traces U.S. coal flotation practice and technological improvements from early laboratory experiments in 1915 up to today's extensive use of the process.

Jan 1, 1999

By Zoë Mullard

The introduction of Web 2.0 platforms (also referred to as social media), with their architectures of participation, has ushered in a new era of technological interaction and information exchange that is changing the nature of corporate-community communications. Web 2.0 platforms give users the ability to generate data collaboratively, meaning that more stakeholders maintain the expectation of being able to contribute to online dialogue. In light of these changes, it is important for business to consider how social media can be used strategically to enhance stakeholder relationships and increase business efficiencies. This article provides three case studies of how different stakeholders in the mining industry are strategically using Web 2.0 platforms to communicate with target audiences. The case studies are based on the experience of respondents and from website observations, which were undertaken as part of a thesis research project by the first author (Mullard, 2010), focusing on the application of social media in the mining industry.

Jan 1, 2011

By Luís Marcelo Tavares, Marko Hilden, Malcolm Powell, Grant Ballantyne, Lian Liu

The t10 relationship developed by Narayanan and Whiten has underpinned a number of the JKMRC models and the characterisation of ore competence through impact testing with the drop weight tester. This usefulness is based on a consistent relationship between the t10 value and the overall size distribution that was noted for brittle rocks. However, like all characterisation tests this should be used only when the controlling conditions apply, which in this case is single impact breakage between two metal platens and within the range of sizes in which fragment sizes are normalizable. For any other mode of breakage the relationship should be confirmed before being applied. Soft ores or bimodal ores with widely different competence between dominant components have non-typical breakage signatures. Breakage via single point impact abrasion, compressed-bed breakage, low-energy surface breakage and incremental breakage, to name some of the other breakage modes, do not obey the general t10 relationship, so their outcomes cannot be used to provide a direct comparison. Inappropriate use of the t10 parameter can result in misleading conclusions about efficiency of energy use. These issues and alternative comparison techniques are presented and discussed in terms of choosing appropriate measures of efficiency of breakage, ore competence and energy required for comminution.

Jan 1, 2014

Geologists working in mountainous terrain were the first to map and interpret in three dimensions and as a result, made the first contributions to our understanding of mountain building and structural geology. However, geology during the 1900s has been dominantly a two-dimensional exercise in data gathering and interpretation. The standard output of geological surveys and university research has been the geological map and the standard methodology of the mineral explorer has been surface mapping and prospecting. The future will be concerned far more with the third dimension.

Jan 1, 1993

By E. T. White

The population balance is one of the basic relations for a:n:aIysing particulate minera1 processing operations. It is an exact relation. The principles of the population balance are reviewed and applications in the minerals industry discussed.

Jan 1, 1996

Many of the world?s largest existing mines are considering substantial step changes in production volumes, compensating for declining ore grades while trying to address increases in world demand for resources. The natural configuration of coal deposits allows for many mine development openings along the strike to access the ore body and thus increase volume. Similarly, with iron ore the nature of the deposits means that additional capacity can easily be added by opening up new mesas and providing extensions to infrastructure. On the other hand most of the non-ferrous metaliferous deposits form vertically and additional extraction volume comes from increasing depth. Underground mining from the base of the strata allows for large extraction rates, but block or panel caving operations develop at rates dictated by the geophysics of the overlying strata and the need for massive tunnelling developments to establish sufficient extraction points for high volumes. For really big mine production capacity, open cast mining still allows the easiest development of more massive mining techniques. But there remains the question of whether there are limits to how large an open cut mine can become in terms of throughput?

Feb 27, 2013

By Stanley A. Bunk, Desmond J. Bruyns

The purpose of roasting gold ores is to release for extraction, typically by cyanidation, the small particles of gold which are surrounded by refractory stone. The roasting simply opens up passages for the penetration of solution into the interior of the ore particles. This is accomplished by the removal by volatilization or formation of volatile oxides of certain constituents such as sulfur, arsenic or antimony. Temperature is an important parameter. High temperatures tend to form a dense iron particle rather than a "spongy" calcine. The dense iron particles result in lower gold recoveries. High temperature can cause melting of some components which also results in gold encapsulation. Roasting of refractory gold ore concentrates has been practiced for decades. Multiple hearth, rotary kiln and muffle reactors were first used for roasting. Fluid bed roasting provided a low capital cost, low maintenance technology with better process control and soon became the favored technology. The first fluid bed concentrate roasters were commissioned in the late 1940's. Early fluid beds were "bubbling" type. Environmental considerations did not significantly impact on the design. Feedstocks were highly exothermic and reaction rates were relatively rapid. Roasting today must compete with other technologies for treatment of refractory ores. Ore bodies which are not

Jan 1, 1993

By AIME AIME

THE 122d meeting of the Institute was held in the Lake. Superior Copper and Iron Country Aug. 20 to Sept. 3, 1920 with an approximate registration of 1100 members and guests. This is the 'first visit of, the Institute to this vicinity since 1904 although previously it held meetings there every six or, seven years. 'The eastern party assembled at Buffalo and sailed on the S. S. "Tionesta ". on Friday morning, Aug. 20, arriving at Houghton, Mich., Monday, Aug. 23. En route stops were made at Detroit, where sightseeing auto trips were taken, and at Mackinac Island, where a short stop permitted a visit to the picturesque and historic Fort Mackinac.

Jan 1, 1920

By Sam H. Patterson

Australia has led the world in bauxite production since 1976, and only the Republic of Guinea has larger bauxite resources. India has a small integrated aluminum industry, and deposits containing more than 1 Gt (billion metric tons) of bauxite were discovered in the 1970's. The Peoples Republic of China has large bauxite resources scattered in several regions, but it is a monohydrate type that is difficult to process for aluminum. Indonesia and Malaysia both have long histories of bauxite mining, and both have limited resources of high-grade bauxite. Districts containing bauxite resources in the 10 Mt to 150 Mt (million metric tons) range are scattered in countries along the eastern rim of the Pacific Ocean, on islands in this ocean, and on the western and northern rims of the Indian Ocean.

Jan 1, 1982

By Spark R. F

The copper deposits at Pernatty Lagoon are predominately djurleite-digenite bodies beneath the permanent water table, and chrysocolla-atacamite-malachite above the permanent water table. The minerals havebeen deposited as sheets, lobes, and pods in zones suggestive of permeability channels or permeability basius with respect to groundwater circulation.Pyrite is deposited in the form of framboids, which reflects its biogenic origin. Copper-iron sulphides deposit by replacement of pre-existent pyrite, and rarely by direct deposition. The latter mode of formation results in complex crustification bandings of chalcopyrite, bornite, sulphur rich bornites, digenite, and blue remaining covellites. The copper-iron sulphides appear to reequilibrate under constrained oxidation, resulting in an iron depletion and associated copper enrichment, the final product of which is a djurleite-digenite assemblage and associated with goethite. Where copper mineralization/ host rock relationships have rendered the rocks entirely impermeable to post ore groundwater movement, then the copper-iron sulphides are preserved as the ore assemblages.Minor and trace minerals observed include sphalerite, carrollite, galena, wittichenite, and possibly tetrahedrite in the primary ores. In the oxidized ores cllprite, tenorite, and trace brochantite have been found.

Jan 1, 1976

By I Gipps

Each of us has a vision of what the future mine will be and, generally, these visions have many similarities and some differences. One of the major discrepancies in visions of the future mine is not the ultimate goal but the path to achieve it. Many of the future concepts require a radical re-thinking of how things are and will be done yet. So how do we reach this visionary future mine? We need a path that satisfies both our future aspirations of a high tech gee-whiz operated from our iPads and the unfortunately mundane approach that says ‘we must know the method works, ie nothing new’.This paper explores how, within a research based organisation, we firstly set our ultimate goal and then divide the path into realistic technology development chunks that would appeal to mining companies to progress within their organisational constraints. Through examples, such as, automated LHDs, communications systems, surveying and localisation, rock cutting and geological sensing, we illustrate how this path will get us from the here and now to the out there future.This paper also demonstrates CSIRO’s short, medium and long-term research in many of the areas needed to create the Future Mine: mining methods, automation and remote control, mine communications, mapping and mission planning, geological sensing and, importantly, human-system integration, which examines how to effectively present data as information to operators and supervisors in an intelligent and useful manner.

Nov 22, 2011

The copper deposits at Pernatty Lagoon are predominately djurleite-digenite bodies beneath the permanent water table, and chrysocolla-atacamite-malachite above the permanent water table. The minerals havebeen deposited as sheets, lobes, and pods in zones suggestive of permeability channels or permeability basius with respect to groundwater circulation.Pyrite is deposited in the form of framboids, which reflects its biogenic origin. Copper-iron sulphides deposit by replacement of pre-existent pyrite, and rarely by direct deposition. The latter mode of formation results in complex crustification bandings of chalcopyrite, bornite, sulphur rich bornites, digenite, and blue remaining covellites. The copper-iron sulphides appear to reequilibrate under constrained oxidation, resulting in an iron depletion and associated copper enrichment, the final product of which is a djurleite-digenite assemblage and associated with goethite. Where copper mineralization/ host rock relationships have rendered the rocks entirely impermeable to post ore groundwater movement, then the copper-iron sulphides are preserved as the ore assemblages.Minor and trace minerals observed include sphalerite, carrollite, galena, wittichenite, and possibly tetrahedrite in the primary ores. In the oxidized ores cllprite, tenorite, and trace brochantite have been found.

Jan 1, 1976

By Raja V. Ramani

As the new millennium approaches, it is appropriate to assess the progress that has been made in mine health and safety, a matter of concern to management, labor and government. One can hardly look at the major events of the last century — from the birth of the US Bureau of Mines through the enactment of the modern health and safety laws — without realizing that the march has been relentless toward eradication of health and safety threats in mining. The progress is spectacular in mine safety and significant in mine health. In looking at the future, it is safe to assume that societal demands will increase for improved health and safety conditions in the workplace. So will the demands for greater technological leaps. The standards will for measuring success and the expectations of progress in creating a safer and healthier mine environment will grow. The possibilities are enormous of meeting these exacting requirements in the 21st century.

Jan 1, 1999

By Lonie W. M

The rapid development of the Australian steel industry over the past twenty years has greatly increased the demand for coking coal from the collieries owned by the Broken Hill Proprietary Co. Ltd. and Australian Iron & Steel Ltd. This in turn has called for an intensive and continuous programme of colliery expansion and new colliery development, along with the reorganization and modernization of existing collieries.This paper presents a general description of the factors involved and the techniques used in planning modern colliery development for the steel industry.PRELIMINARY GEOLOGICAL INVESTIGATIONSIn any colliery development, preliminary geological investigations require a detailed and practical knowledge of the geology and characteristics of the coal-field as a whole. In the early stages of the investigations, probably the most valuable information is obtained from outside the particular area under review, rather than within it, and unless the geology of the coal-field is understood, the projection of the known information into the unknown area cannot be carried out with certainty.Because development of the coal seams from the outcrops has been an apparently simple matter and not subject to the risks involved in deep mine development, the geology of the New South Wales. coal-fields has not received the attention that major mineral resources warrant.Only the most accessible regions of the coal measures have been generally prospected, while the potential areas remain...

Jan 1, 1957

By P J. Grobler

The current commodity boom is depleting the ore bodies at a rate not seen in the past. As the existing ore bodies get depleted, only the more inferior bodies are left for exploitation. This places an emphasis on beneficiation to upgrade the lower grade ore to high-grade feedstock for downstream processes. This paper discusses the role of dense medium separation in this quest for high-grade feedstock for the future. It covers the production and utilization of ferrosilicon and gives a future perspective of the technology. It concludes about the way ahead and the challenges facing the processing fraternity and mining industry.

Jan 1, 2006

The Australasian Institute of Mining and Metallurgy and the Australian Mining Industry Council are concerned that a sufficient number of able young people receive an adequate level of professional training for the mineral industry. A Joint Committee on Education has been formed to pursue these objectives. At a time of strong growth in the industry it is most important to forecast the demand for people, so that the educational authorities will be able to provide adequate facilities. The factors to be considered in fore- casting the demand for professional staff are set out, and the proposed method of assessment is outlined.

Jan 1, 1981