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By Williams ID

Ore and coke of various size fractions (1 to 11 mm) were packed in a column (146 ó) and resistance to air flow measured under a range of conditions. Results have shown that layered charging results in an interface having essentially a directional structure the thickness of which is directly proportional to the coke and ore size ratio and whose flow resistance exceeds that of the coke layer many times its thickness. Friction factor - Reynolds number plots showed large positive departure from the Ergun equation for all components investigated whilst functional analysis and that in terms of bed constants, showed a strong dependency of the pressure gradient on bed properties and the actual particle size as well as the size ratio. It is also shown that pressure gradient in mixed beds follows previously reported behaviour and that a directional interface offers higher resistance to flow than a mixed interface having the same volumetric ore/coke ratio. Significance of results to practice is discussed.

Jan 1, 1975

By James J. Bean

Although determining and controlling specific gravity of operating medium in a heavy-media plant manually presents no problem, there are advantages to automatic recording and control. The two installations discussed employ the usual method of measurement. Pneumatic control with band control and reset features is used to regulate dilution water and hence specific gravity. Difficulties have been mechanical in nature and associated with obtaining a proper sample and maintaining tight air connections in bubble-tube piping.

Jan 3, 1950

By Richard S. Watt

The Bureau of Mines is often called upon to analyze the demand for various minerals and fuels and to make projections of the future demand. Because minerals and fuels are raw materials and because the demand for raw materials [pends] on the demand for finished goods, these projections are usually [conned] with derived demand rather than final demand. In order to obtain quick [d] reasonably accurate analyses of the demand for mineral commodities, the [reau] developed a method and has used it successfully (31).4 To illustrate the [thod], this report presents a full analysis of the demand for a mineral commodity with enough general theory to permit application of the method to any mineral. Sodium chloride (common table salt) was chosen as the subject of the analysis because the demand for it is less complicated5 and permits a simple application and clear presentation of the method.

Jan 1, 1962

By Robert E. Thurmond, E. D. Spaulding, Walter E. Heinrichs

DISCOVERY of a commercial ore deposit has resulted from a program emphasizing geophysical techniques and concentrating upon exploration of alluvial-covered areas. United Geophysical Co. selected these areas as offering the best possibility of success, for here the surface evidence of ore deposits has been hidden from the eyes of prospector and geologist alike. Pima mining district, Pima County, Arizona, was selected for initial exploration. The project was successful in that a commercial ore deposit was discovered and proved through drilling and extensive underground development.

Jan 2, 1954

By George A. Snyder

The presence of moderate to high concentrations of colloidal clays in coal preparation plant waters can cause serious operating and economic problems for a coal company. Among the host of possible problems are the following: 1) Poor separation of clays in the plant thickener, resulting in: a) Increased ash in the clean coal. b) Increased specific gravity of the wash water and decreased coal recoveries at the desired quality. c) Increased thickener operating costs in trying to overcome the problem. 2) Decreased solid concentrations in the thickener underflow and increased pumping requirements to meet solids withdrawal requirements.

Jan 1, 1979

By C DahnTr-Lindqvist

The Kiruna mine produced about 19 Mt processed iron ore in 1999 using sublevel caving. General failure in the hangingwall has been widely studied and its mechanism is rather well understood. Failure in the footwall is more recent and not perfectly explained. Plane shear failure and Hoek and BrayÆs circular failure charts were successfully used to match the first surveyed failure surfaces. The footwall is not free yet but covered by a caved waste rock abutment whose exact behaviour is poorly known. Based on new field data and numerical models (FLAC), the following paper presents recent improvements in understanding the Kiruna mineÆs footwall failure process.

Jan 1, 2000

By J. -C. Sztuke, M. Cao

ABSTRACT Wash water and polyethylene oxide (PEO) were used in the flotation of quartz and coal. Wash water decreased entrainment of –15 µm quartz. The optimum superficial wash water rate was 0.05 cm/s. PEO also lowered entrainment. The combination of wash water and PEO led to a slight further reduction in entrainment. For 1:1 mixtures of –15 µm quartz and –300 µm oxidized coal, the combined use of wash water (0.05 cm/s) and PEO increased the separation efficiency from approximately 30% to > 70%, whereas wash water alone at 0.05 cm/s did not lead to a discernible increase.

Jan 1, 2014

By David White

THE environmental conditions under which coals are deposited are revealed by the stratigraphy of the coal basins and coal beds and by the details of the structure and the physical constitution of the coals themselves. THE LAND SURFACE Generally Low Relief or Base Level In the Paleozoic coal fields, which have longest been worked, are most important, and are best known, we find relations, in general, as follows A post-Mississippian uplift with, in most cases, very moderate deformation, followed by erosion by which the uplifted regions, especially the bolder of the new topography, were largely worn down, while the older and less deformed regions were more or less extensively base leveled. Base leveling of most of the region continued as the deposition of coal measures proceeded. Consequently, in most coal fields the Pennsylvanian, or upper Carboniferous, lies unconformably on the Mississippian or on older formations. There are but few regions in which sedimentation is seen to have been apparently continuous from the Mississippian into the Pennsylvanian ("Coal Measures").

Jan 1, 1925

By L. S. Castleman, R. Resnick

The self-diffusion coefficient of columbium has been measured over the temperature range 1535o to 2120°C, using the radioactive isotope Nb95 as the tracer. The data for the temperature dependence of the self-diffusion coefficient are best fitted by the equation D = (12.4 ± 0.8) exp [(-105,000 ± 3000)/RT] cm2/sec. THE increasing need for high-temperature structural materials has stimulated considerable interest in the properties of columbium, since it is a strong, ductile metal with a high melting point—in the vicin- ity of 2450oc.l One fundamental property which has not heretofore been measured is the self-diffusion coefficient. The self-diffusion coefficient plays an important role in theories of oxidatioq2 creep,' sintering4 and other phenomena. Accordingly, the investigation reported in this paper was undertaken to determine the value of the self-diffusion coefficient and its temperature dependence by the use of Mb95.

Jan 1, 1961

By Afranio Marcio Costa

No lingotamento contínuo a busca pelo aumento de produtividade tem sido realizada com sequências longas, ou seja, várias corridas e muitas vezes com aços de diferentes composições químicas. Isso resulta na geração de placas de mistura e vários trabalhos buscam entender este processo. Este estudo tem como objetivo validar o modelo matemático de mistura existe no lingotamento da Gerdau Ouro Branco para garantir a correta aplicação da região de mistura, visando atender às especificações dos produtos, norma ASTM A36. Os resultados encontrados nas placas amostradas confirmaram a eficiência do modelo para estimar a zona de mistura. Além disso, para garantir a aplicação dessas placas na norma estudada foi utilizado o modelo de previsibilidade de propriedades mecânicas existente na laminação de chapas grossas. Finalmente, os resultados reais de composição química, limite de escoamento e resistência encontrados nas chapas avaliadas confirmaram as previsões dos modelos e atenderam às especificações do aço.

Oct 30, 2017

By M. Adnan Göksel

Pyrite cinder is generated by roasting pyrite for sulfur dioxide production. It contains up to 62% iron, but also may contain other hazardous or toxic materials such as Zn, Pb, As, T1, Cd, Cu, Sn and S. Furthermore, the physical characteristics are not properly suited for conventional sintering. As a result pyrite cinder is considered to be unsuitable for iron and steelmaking or for outside storage because of its potential for causing environmental problems. In recent years industrialized nations have put increasing pressure on the manufacturers to either use such waste products or properly dispose of them. In this study, solutions to both the iron recovery and disposal problem were attempted by pelletizing the pyrite fines with internal carbon. The pellets, after hydrothermal hardening, were reduced and melted in a furnace for hot metal production. Hot metal of usuable quality was produced and the hazardous materials were either collected with the fumes or in the slag.

Jan 1, 1984

By Wayne W. Murdy

Since 1993, Newmont Mining has been growing through the development 'q of three major foreign mining operations with a fourth under construction. The first project, Yanacocha in Peru, began operating in October 1993. This occurred at a time when political and business risk in that country was considered high. In 1995, Newmont began operating the Muruntau joint venture in Uzbekistan. It is the first mining project of its kind in the Confederation of Independent States (CIS). In early 1996, Newmont started operating the Minahasa Mine in Indonesia. In early 1997, Newmont began construction of a $1.9-billion project in Indonesia. The company is also completing a feasibility study with its partner for the development of a gold operation in Mexico. All of these projects have been considered "risky" by most standards. Newmont has been successful in all of them through risk mitigation programs. These programs include using strong and successful in-country partners, concentrating on developing a strong national workforce with minimal expatriate employees, using World Bank, European Bank for Reconstruction and Development (EBRD) and International Finance Corp. (IFC) financing and building and maintaining strong ties with host governments.

Jan 1, 1997

By Jim Rozek, Robert A. Gee

The Epping to Chatswood Rail Line project is the largest publicly funded infrastructure project in New South Wales. Construction commenced in November2002 with opening scheduled for 2008. The work includes 13 route km of twin TBM driven 7.2 m diameter lined running tunnel, three cross-overs and three new underground stations. The new stations have platform caverns of 20m span with similarly proportioned concourse caverns alongside. The ground is bedded sand stone and shale with high horizontal stresses. Predicted stress-relief induced ground movements during staged excavation led to innovative use of rock anchors for permanent support.

Jan 1, 2005

By L Köresaar, J Moilanen

With lower and increasingly variable Fe grades in iron ore resources, the monitoring of Si, Al, Mg and other light elements to meet quality requirements is gaining importance in the iron ore beneficiation industry. The high cost per manual assay and associated manpower requirements often limit the frequency of shift composite samples and laboratory assays. Furthermore, the shift composite assays represent past performance of a plant but are not useful for immediate reactions to feed variations, detection of equipment malfunctions or process control. Automated online analysis of light elements radically reduces the cost per assay and provides repeatable, timely data for process analysis, control and optimisation.A light element online slurry analyser, based on laser-induced breakdown spectroscopy (LIBS) optical emission technique, will be presented. This paper discusses the analyser design for the iron ore industry and also reviews the performance of the analyser against the manual laboratory. Additionally operator safety, user friendliness and maintenance requirements are discussed.A case study will also be discussed in this paper. The sophisticated measurement technique has been implemented in an industrial automated analyser and sampling system to allow for slurry measurement for up to 12 sampling points. However, careful selection of the sampling points and implementation of the sampling system is required for smooth operation.CITATION:Köresaar, L, Timperi, J and Moilanen, J, 2015. Optimised process control in iron ore via online analysis of light elements, in Proceedings Iron Ore 2015, pp 511–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Alessandro Blasi, Massimo Morgana, Corradino Sposato, Pietro Garzone, Giuseppe Devincenzis

The rare earth elements are essential for a diverse and expanding array of high-technology applications, which constitute an important part of the industrial economy of the 21st century. As a matter of fact, rare earth has been listed in the category of strategic elements in many countries becoming a core business for international research. Experimental tests have been carried out on a bench scale battery of mixer settler composed of 24 stages, each one with a volume of 150 ml. These trials have been performed at room temperature checked by a micro-climatic control system. The battery was setted in two sections: extraction and scrubbing section. Rare earths concentrations were obtained by ICP-OES analysis made on aqueous phase and on the stripped from organic phase. We obtained a complete separation of light rare earth (La, Ce, Pr, Nd) in two sub-groups: La/Ce and Pr/Nd.

Jan 1, 2014

By W. Burger

For the development of deep hard rock mines fast access to the orebody is critical. In some cases the mineralized area is more than 1500 m (5000 ft) below surface. Excavation of shafts or declines is typically on the critical path of the project schedule. Saving time on those activities can significantly increase the net present value of the mining project. Mechanical excavation methods are a step-change in excavation performance and labor safety compared to drill and blast operations. In hard rock conditions roadheaders can not be used effectively, so disc cutting is the first choice. For excavation of declines tunnel boring machines (TBM) can be used in many cases. These provide in certain rock conditions considerably higher production rates compared to drill and blast excavation.

Jan 1, 2010

Before presenting this address I desire to express my appreciation of the honour which has been conferred on me by my election as iPresident of The Australasian Institute of Mining and Metallurgy. At this stage it might not be out of place to recall that Broken Hill was the birthplace of The Australasian Institute of Mining and Metallurgy, originally formed as the Australasian Institute of Mining Engineers in 1893.In selecting for my address the topic of "The Broken Hill Mining Industry and its Contribution to the Economy of Australia" I realise it is impossible to cover fully every aspect of the nation's economy which owes all or part of its origin to the Broken Hill field. Nevertheless, I feel that some attempt should be made to give credit to the Broken Hill mining industry for its part in the progress which Australia has made over the past seventy years.. If we care to reflect for a moment it soon becomes apparent that, not only is the Broken Hill mining industry an important producer of base metals for domestic and overseas consumption, but its profits have provided the means whereby many of Australia's leading secondary industries have been established or built up. Examples which come to mind are the founding of the iron and steel industry by the Broken Hill Proprietary Company; the establishment of plants at Port Pirie in South Australia, and at Risdon in Tasmania, for the production of metallic lead and zinc; and also at Port Kembla for the smelting of copper ores. From profits derived from operations at Broken Hill, capital has also been provided to assist other new essential...

Jan 1, 1956

By W. W. Adams

[The s1xteeilth an.nual National Safety C mpeti t1on, concluc ted "by the Bureau of t4ine g, Un+ ~ed st tag' DepartIilent 0:1' the Interior, has jast been closed, and the results reveal t:'W.t. t_!e co~)eting comps.nies had fewer a.ccidents in proportion to the number. of !\1a..."1-h(J1J.l'~ :orkcd than in a:ny other yeex in the record of the contest. These annUk~l contestn are thus achieving the r purpose of promoting safety in tho minin induC'tr:r. ]

Jan 1, 1941

By E. C. Houston, H. S. Rankin

Olivine is considered a valuable potential source of metallic magnesium in the chloride electrolytic process. Treatment of olivine with hydrochloric acid can be carried out under conditions that prevent the formation of gelatinous silicic acid, which would inhibit the reaction by forming a covering around the ore particles. It is our hypothesis that the formation of gelatinous silicic acid is avoided by the dehydrating action of the magnesium chloride, which takes up water to form a series of hydrates and leaves the silicic acid in granular condition. Leaching serves to separate the magnesium chloride from the silicic acid and unattacked ore, which can be treated with fresh acid in successive steps until extraction is essentially complete. The leach solution can be i purified by the addition of caustic magnesia and the precipitated impurities removed by decantation or filtration. The resulting magnesium chloride contains: Fe, less than 0.001 Per cent; Mn, 0.012 ; per cent; Ni, none. Chlorination† of olivine has two major defects: (1) a large part of the chlorine goes to form silicon and iron chlorides, (2) the anhydrous magnesium chloride is held by absorption in the finely divided silica. SupplY It is well known that olivine, a silicate of magnesium and iron, is present in large amounts in several localities in the United States. The largest deposits occur in the southeast and on the Pacific Coast.' The southeastern deposits were surveyed by Lewis2 in 1896 and by Hunter3 in the period 1933-1940 It is estimated that high-grade olivine, conveniently located with regard to transportation and power, is present in excess of 230 million tons above local drainage level in western North Carolina and north Georgia. Previous Technical Work In the past few years, olivine has attracted considerable attention in the refractory field. In the chemical processing industry, however, it has long been thought axiomatic that the cost of processing silicates is an economic barrier to their utilization, especially where more reactive minerals, such as carbonates, oxides or salts, are available. This attitude is not entirely justified in connection with olivine. unlike most silicates, olivine is readily attacked by acids, chlorine and other reagents without resorting to fusion to break down the silicate structure. Olivine has been suggested as a raw material for making epsom salt by roasting with pyrites.4 Other processes include acid treatment6 and digestion with calcium chloride.6 Recently a small plant was built near Webster, N. C., for making epsom salt from olivine by treatment with sulphuric acid. This plant is now in commercial operation, producing approximately two tons per day. Olivine is also receiving attention from the fertilizer industry as an inexpensive source of soluble magnesium.

Jan 1, 1942

By H. S. Rankin, E. C. Houston

Olivine is considered a valuable potential source of metallic magnesium in the chloride electrolytic process. Treatment of olivine with hydrochloric acid can be carried out under conditions that prevent the formation of gelatinous silicic acid, which would inhibit the reaction by forming a covering around the ore particles. It is our hypothesis that the formation of gelatinous silicic acid is avoided by the dehydrating action of the magnesium chloride, which takes up water to form a series of hydrates and leaves the silicic acid in granular condition. Leaching serves to separate the magnesium chloride from the silicic acid and unattacked ore, which can be treated with fresh acid in successive steps until extraction is essentially complete. The leach solution can be i purified by the addition of caustic magnesia and the precipitated impurities removed by decantation or filtration. The resulting magnesium chloride contains: Fe, less than 0.001 Per cent; Mn, 0.012 ; per cent; Ni, none. Chlorination† of olivine has two major defects: (1) a large part of the chlorine goes to form silicon and iron chlorides, (2) the anhydrous magnesium chloride is held by absorption in the finely divided silica. SupplY It is well known that olivine, a silicate of magnesium and iron, is present in large amounts in several localities in the United States. The largest deposits occur in the southeast and on the Pacific Coast.' The southeastern deposits were surveyed by Lewis2 in 1896 and by Hunter3 in the period 1933-1940 It is estimated that high-grade olivine, conveniently located with regard to transportation and power, is present in excess of 230 million tons above local drainage level in western North Carolina and north Georgia. Previous Technical Work In the past few years, olivine has attracted considerable attention in the refractory field. In the chemical processing industry, however, it has long been thought axiomatic that the cost of processing silicates is an economic barrier to their utilization, especially where more reactive minerals, such as carbonates, oxides or salts, are available. This attitude is not entirely justified in connection with olivine. unlike most silicates, olivine is readily attacked by acids, chlorine and other reagents without resorting to fusion to break down the silicate structure. Olivine has been suggested as a raw material for making epsom salt by roasting with pyrites.4 Other processes include acid treatment6 and digestion with calcium chloride.6 Recently a small plant was built near Webster, N. C., for making epsom salt from olivine by treatment with sulphuric acid. This plant is now in commercial operation, producing approximately two tons per day. Olivine is also receiving attention from the fertilizer industry as an inexpensive source of soluble magnesium.

Jan 1, 1942