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By J. Convey, S. L. Gertsman

"THE EXPANSION of steel capacity is seldom spectacular. It may be for this reason that the remarkable progress made in Canada has not been generally recognized. In 1950, Canada's output of steel ingots amounted to 3,270,000 tons ( l ), which is a ll8 per cent increase over the tonnage produced in 1939. It can therefore be readily seen that Canada's growth curve for steel production is climbing at a rate paralleling her growth as a nation. It is by no means •an exaggeration of its importance to consider the steel industry as the cornerstone in the economic structure of Canada's manufacturing activities. From the humble diaper pin to the giant members of massive bridges, fortifications, and other steel structures, steel accompanies us as a necessary and inescapable companion in our journey through life. The Age of Steel has a literal meaning, and refinements in the manufacture of the products of steel are adapting it to more and more varied uses as time passes.The integrated iron and steel works of Canada fall into two natural geographical divisions. One has its base on the Great Lakes and draws its supply of •coal and some of its ore from the United States. In this division lie the works of the Algoma Steel Corporation, at Sault Ste. Marie, at the junction point of lakes Huron, Superior, and Michigan; and the works of The Steel Company of Canada, at Hamilton, on lake Ontario."

Jan 1, 1952

By J. C. Judd

The U.S. Department of the Interior, Bureau of Mines investigated solvent extraction methods for recovering gallium from filtrates produced from sulfuric acid leaching of hydrometallurgical zinc residues. These filtrates typically had pH values of 0 to 0.5, too high an acid content for effective gallium recovery by traditional extractants. Of the nine extractants studied in batch tests, 0.3M octyl phenyl acid phosphate (OPAP) in a kerosene diluent was the most effective extractant for gallium recovery, extracting up to 99.9 pct of the gallium. This high extraction was possible when the iron in solution was maintained in the reduced ferrous state. Batch tests also showed that a 1.5M-H2SO4 strip liquor recovered 98 pct of the gallium from the loaded OPAP. A continuous solvent extraction system was designed and operated based on McCabe-Thiele analyses of equilibrium loading and stripping isotherms. When 12 L of leach filtrate containing 0.32 giL Ga and 20 giL Fe were pumped through the system in 32 hr, results showed that 95 pct of the gallium was extracted in four stages at an A:O ratio of 1:1. Stripping the loaded solvent with a 1.5M-H2S04 liquor recovered 94 pct of the gallium in four stages at an A:O ratio of 1:4. A two-stage, 50-pct-phosphoric acid strip successfully removed ferric iron from the OPAP, allowing high gallium extractions to be maintained.

Jan 1, 1990

By B. Manoj

Coal is a mineral and is extensively used as a solid fuel in developing nationsand hasa sizeable share inthe global fossil fuel reserve. Utilization of this resource generates excess spoil and large volume of low grade waste to the environment. In recent years there have been serious research on enhancing its value and exploring the utility of this carbonaceous material to novel carbon materials.

Mar 1, 2018

By Sabri Ergun, Robert W. Smith, Victor H. Tiensuu

Factual geometries are considered for X- ray scattering studies of weakly absorbing materials by both reflection and transmission methods . These studies are usually made on slab specimens to obtain adequate scattered intensities ; however , the intensities are appreciably influenced by absorption of the X-rays in passing through the specimens . Conventional equations derived to account for this absorption are based on idealized geometries , but for polycrystalline carbons the use of idealized geometries leads to several percent error in the corrections to be made . Use of factual geometries substantially reduces this error .

Jan 1, 1964

By Gustavo Henrique Bolognesi Donato

O projeto e a operação de estruturas que podem vir a conter trincas demandam estudos de integridade estrutural suportados por propriedades mecânicas à fadiga e à fratura advindas de ensaios experimentais (p. ex.: curvas J-R ou da/dN vs. ?K), sendo tais experimentos altamente dependentes da medição instantânea do tamanho da trinca. Essa medição em muitos casos é realizada com base na variação da flexibilidade com o crescimento do defeito. O objetivo do presente trabalho é validar experimentalmente soluções numéricas recentes de flexibilidade elástica que descrevem o tamanho instantâneo de uma trinca em corpos de prova de geometria C(T) e SE(B) incorporando efeitos tridimensionais. Ainda, objetiva comparar tais soluções com as disponíveis nas normas ASTM vigentes. Corpos de prova C(T) e SE(B) foram usinados conforme as referidas normas e testados em máquina universal de ensaios MTS 810.25. Na sequência, os dados obtidos foram convertidos em valores de flexibilidade normalizada (µ), determinando-se o tamanho de trinca (a) esperado com base nos referidos equacionamentos. As previsões de tamanho de trinca geradas foram comparadas com medições reais da profundidade de trinca obtidas de fractografias das amostras após separação final. No geral, tanto as soluções da ASTM como de Moreira (2014) foram consideradas acuradas e com erros máximos abaixo de ~ ±1,5%. No entanto, os resultados mostram equivalente aderência experimental das soluções disponíveis nas normas ASTM com as de Moreira (2014) para amostras C(T), mas melhor desempenho das propostas de Moreira para amostras SE(B) de variadas geometrias e profundidades de defeitos.

Aug 17, 2017

By B. Das

The processing of banded iron ore by direct anionic and reverse cationic flotation to produce pellet grade concentrate is investigated. This low-grade iron ore, known as banded hematite quartzite (BHQ) contains 41.8% Fe, 41.5% SiO2, 1.2% Al2O3, and 0.5% LOI. The flotation behavior of BHQ is studied by varying the effect of concentration of collector, frother, dispersant and pH. Oleic acid and dodecylamine are used as the anionic and cationic collectors respectively. The parameters that gave the best results in cell flotation are utilized in 100 mm diameter flotation column. All the results are compared with regard to the iron grade and recovery in concentrate. It is observed that, anionic collector with dispersant dosage of 220 g/ton, at pH ~8.5 is selective and yielded a high-grade iron concentrate with low silica as impurity. Also, it is possible to achieve an iron concentrate with 64% Fe at 30-37% weight recovery. The characterization studies of the BHQ ore using X-ray diffraction (XRD) technique and liberation analysis with QEMSCAN® are carried out. The sample contains 58.8% hematite and 37.7% quartz and the liberation of hematite particles are found to be 90.3% in -25 µm size. An alternative statistical modeling approach called response surface methodology was also undertaken to optimize the operating parameters in order to maximize the iron grade and recovery. The predicted results by the model are in agreement with the experimental values.

Sep 1, 2012

By D. Harrington, C. W. Owings

The mining industry is gradually realizing that safety education and safety inspection are economic factors that may not be overlooked as a means of reducing operating costs . Many mine operators , however , have failed to realize the benefits of safety , and the efforts of the more progressive mining companies are offset by the carelessness of neighboring companies when the accident records of a community or a State or the nation as a whole are considered . This tendency is indicated by the data collected by the safety division of the United States Bureau of Mines . During the fiscal year ended June 30, 1930 , relatively definite information: was secureä concerning 34 mine explosions , 24 mine fires , and 29 miscellaneous accidents ; these accidents are by no means all of the explosions , fires , and miscellaneous accidents which occurred in the mines of the United States during the period; but the data on the fires and explosions constitute a record of all of those types of accidents that were called specifically to the attention of the safety division , and the miscellaneous accidents include those on which definite , detailed data were obtained by the safety division .

Jan 1, 1931

By R. F. Farrell

A goal of the U.S. Department of the Interior, Bureau of Mines, is the advancement of minerals technology through the development of improved metals and minerals processing. In support of this goal, the Bureau of Mines has developed a general method for preparing solutions from a wide range of metal and mineral samples for chemical analysis. The development of the method from current knowledge of vessel material, pressure dissolution techniques, and the fluoride-boric acid reaction is given. The method uses 7 ml of a mixture of HC1-HNO3-HF acids in a ratio of 3.5:2:1.5 sealed in plastic bottles that act as pressure vessels when heated in a boiling water bath. A final volume of 100 ml is obtained by the addition of 93 ml of a 1. 5-pct H3BO3 solution to the bottles, which are reheated; precipitated fluorides as well as sample residue are dissolved by the fluoride-boric acid reaction. A copper slag and a steelmaking slag treated using this method were analyzed by atomic absorption spectroscopy yielding values for Si, Mg, Ca, AI, Fe, Mn, Na, As, Pb, Sb, and Zn very close to certified values with an average relative standard deviation of 2.13 pct. The low cost, reduction in preparation time, ease and safety of sample handling, conservation of reagents, and ability to dissolve volatile materials without loss make this method superior to traditional wet digestion techniques for many materials, and ideal for use with atomic absorption, and optical emission or X-ray emission spectroscopy.

Jan 1, 1980

By S T. L Harrison, J-P Franzidis, M Becker, N Dyantyi, J L. Broadhurst

Gold mining is a major contributor to the South African economy, but is associated with several environmental issues such as acid rock drainage (ARD). ARD is due to the oxidation of sulfides in gold tailings and is characterised by low pH, high sulfate content and elevated concentrations of heavy metals that contaminates scarce water resources and subsequently limits the use of such waters without treatment. Treatment strategies can only be implemented if the acid-generating potential of mine wastes is effectively predicted using common static and kinetic acid prediction tests. The choice of test performed is usually a trade-off between the number of samples, speed of the test, cost of the analysis and level of information obtained. Often the results of these various tests are not consistent with one another. This study uses mineralogy to analyse biokinetic test results of a Witwatersrand gold sample in order to improve the understanding of behaviour of mine wastes under different ARD prediction test conditions.All ARD prediction testing methods investigated in this study showed that the gold sample is considered to be potentially acid forming with net acid generation (NAG) pH of 2.5 and net acid producing potential (NAPP) of 36 kg H2SO4/t. Results of biokinetic test showed that ANC was consumed within four days confirming acid producing potential of the sample with low neutralising potential as observed from acid base accounting (ABA) (4.7 kg H2SO4/t) and mineralogy (4.9 kg H2SO4/t). Results generated in this study demonstrated importance of mineralogy in both understanding the controlling reaction mechanisms playing key role in ARD formation and its capability as a prediction technique. Future work will focus on the application of mineralogy in interpreting the behaviour of mine waste under different static test conditions with a view to assessing their applicability and reliability in estimating potential acid generating characteristics of gold tailings.CITATION:Dyantyi, N, Becker, M, Broadhurst, J L, Harrison, S T L and Franzidis, J-P, 2013. Use of mineralogy to interpret laboratory-scale acid rock drainage prediction tests - a gold case study, in Proceedings World Gold 2013, pp 519-526 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By M I. Pownceby

High temperature roasting studies on chrome-spinel contaminated ilmenite concentrates showed that sulfur, introduced through a sulfidising roast treatment, selectively reacted with the chromium in the spinels. The roast treatments were carried out in a laboratory scale rotating drum kiln using a standard Becher-style heating profile (10 h, 1075ºC), char as the reductant, and variable amounts of added elemental sulfur (0 - 3 wt per cent).After roasting, bronze-coloured grains were visible representing chrome-spinels that had undergone selective sulfidisation. SEM imaging of the products showed that sulfur was preferentially concentrated in ~5 - 15 µm thick rims fully enclosing the chrome-spinel grains. The sulfur-rich rims became a sink for manganese (Mn) from the ilmenite resulting in the rims being rich in Cr-Mn-Fe-sulfides. Quantitative electron probe microanalysis of phases present within the rims identified two sulfide phases. The first sulfur-phase (S-phase) was low in Mn (1 - 3 wt per cent) and high in Fe, Cr and S, while the second S-phase was considerably higher in Mn (30 - 35 wt per cent Mn) and lower in Fe and Cr. The dramatic change in the composition of the chrome spinels after sulfidisation is likely to significantly alter their physical properties (eg hydrophobicity, conductivity, etc). This should make their physical separation from the ilmenite potentially easier than roasting/magnetic separation methods.

Oct 5, 2011

By Frank H. Skelding

A new, large mine is about to be born. Many years and millions of dollars have been invested in exploration. An orebody has been found and proven. All necessary political and legal work to establish rights and conditions for development are complete. The feasibility studies are favorable. Financing has been arranged. Board approval has been given to proceed. The time has come to engage a contractor to design and build the new facilities in a location, as is the common case today, far re¬moved from the centers of advanced technologic development where the minerals will ultimately be used. A select list of Engineering and Construction (E&C) companies is asked to prepare proposals. At this point the common viewpoint among mining companies is that the company's sole remaining problem, a major one to be sure, is to select qualified contractors to design and build the project at the lowest cost and shortest time possible so that production can start generating a return on investment. The purpose of this discussion is to explore the viewpoint of the large E&C contractor toward such projects. It differs in important ways from that of the client mining company and it is these differences and the reasons for them that must be understood by the client if severe difficulties and misunderstandings with the contractor, starting at the beginning of contract negotiation and continuing through design and construction to final startup are to be avoided or minimized. Often enough, the difference is in degree, not kind, which only serves to obscure the fact that a difference exists.

Jan 1, 1975

By Thomas M. Barczak

Wood cribs are used extensively by the mining industry to stabilize mine openings. While the cost per crib is relatively low, their extensive use can result in annual mine costs of over $1 million. In an effort to improve the utilization of these supports and to reduce ground control hazards, the U.S. Bureau of Mines has developed engineering methods to assist mine operators in wood-crib design and employment. Design and employment criteria are established based on the strength, stiffness, and stability of the crib structure in relation to the load conditions imposed by the mine environment. Models have been developed based on full-scale tests in the USBM's Mine Roof Simulator that compute the capacity of wood cribs of various configurations and material constructions as a function of displacement of the crib structure due to roof-and-floor convergence. These models permit the comparison of the loading characteristics and costs of employment of different crib designs, and in conjunction with roof behavior models, provide a means to determine the optimum design and employment strategy.

Jan 1, 1993

By Arcelor Mittal

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Jan 26, 2018

By J. L. Shultz

Mass spectrometric analyses were obtained for naphthalene and anthracene oils, heavy creosote, and three fractions of a pitch. The average molecular weight, aromaticity, and mean structural unit were determined for each fraction. The investigation of these fractions of coal tar has resulted in semiquantitative data for 38 structural types and carbon number distribution data for their alkyl derivatives. The molecular weights of 10 of these structural types indicate ring systems not previously reported in products from high-temperature carbonization of coal. Two of these structures are poly-nuclear aromatic hydrocarbons, two are oxygen-containing compounds, one contains sulfur, and five are nitrogen-containing compounds.

Jan 1, 1967

By Isauro Rivera Landero, Martín Reyes Pérez, Eduardo Cerecedo Sáenz, Javier Flores Badillo, Mauricio Guerrero Rodríguez, Juan Hernández Ávila, Eleazar Salinas Rodríguez, María Isabel Reyes Valderrama

During column flotation of mining tailings of the Dos Carlos dam, it was observed that the effect of surface liquid flow (JL) is a variable that determines the rate of rise of packing bubbles and therefore, causes the generation of gas retained within the columnar system. Also overall more stable laminar flows were observed, in a range of superficial flow of liquid in the bottoms stream (JLT) from 0.446 to 0.68 cm/s, showing the stability in the range of superficial gas flow (Jg) from 0.1 to 0.5 cm/s. Observing a uniform bubble size for the three JLT evaluated, with a diameter between 0.05475 and 0.2525 cm, at all the range evaluated of Jg. Furthermore, an uniform performance was obtained, and with the same rate of rise of packing bubbles, showing a greater packing bubbles at JLT = 0.446 cm/s, due to the lesser bubble size observed, in comparison with the values of JLT of 0.68 and 1.017 cm/s.

Mar 1, 2017

By R Whittering, C Greet

High chrome grinding media has been used in the mining industry for quite some time, as it often proves economical on a wear basis. However, it is unusual for an operation to change to high chrome solely due to its metallurgical benefits. KagaraÆs Mount Garnet operation made the change from forged steel to high chrome media after laboratory testwork indicated that copper grades and recoveries would improve. The outcome was remarkable with positive changes in pulp chemistry throughout the circuit accompanied by marked improvements in copper, lead and zinc grades and recoveries. Reagent dosage rates were reduced, often by more than half, and the grinding media wear rate dropped to less than a third of the wear rate of the forged steel media. The economic analysis showed that out of the total increase of revenue and savings from metallurgical improvements and reagent and media consumption reductions the metallurgical improvements made up approximately 73 per cent, the reduced reagents saved 25 per cent and the savings through reduced media wear contributing by just over one per cent. This indicates that the popular view of high chrome media only being trialled in the plant for wear economics is outdated and the focus of operations should be shifted to using high chrome media for the metallurgical benefits.

Jan 1, 2006

By Alexander Schultz Rizek

O trabalho que será apresentado irá descrever o projeto realizado de atualização tecnológica do sistema de controle com controladores Automax instalado em um laminador de fio máquina de dois veios, a Acerías Paz del Río, da Votorantim Siderurgia na Colômbia. Este projeto consistiu na substituição do antigo sistema de controle com PLC’s Automax do laminador fio máquina de dois veios, mantendo-se parte do sistema antigo Automax convivendo com o novo sistema Contollogix. O novo PLC instalado para o controle do laminador foi o Rockwell ControlLogix, através do qual foi desenvolvido o controle principal do laminador, como: cascata de velocidade utilizando o fator R, que poderia ser ajustado do IHM (antes os ajustes eram feitos diretamente no rpm dos motores), controle de laços, controle das mesas de laço, as primeiras da Russula, produzidas e programadas em companhia com a Russula Itália exclusivamente para esse projeto, controle de tração, ciclos de posicionamentos manuais e automáticos, intertravamentos, etc.

Jul 30, 2018

By C. A. Pearson, W. D. Dietzman, M. E. Hawkins

Results of chemical analyses and electrical resistivity measurements of 422 samples of oilfield brines from 120 east Texas fields in Railroad Commission of Texas Districts 5 and 6 are presented in tabular form . These samples represent water from all of the major petroleum- productive formations in the area . Water analyses and electrical resistivity data , when fully utilized by proper study techniques , are useful tools in the solution of many engineering problems such as detection of well leaks , identification of water sources , and interpretation of electrical well logs . In the area included in this study , these representative data should facilitate the solution of problems in which water analysis and water resistivity are factors .

Jan 1, 1964

By Jarinson Ribeiro Rodrigues

Os aços resistentes à abrasão da classe 450 HB foram desenvolvidos para operações em ambientes onde ocorre desgaste excessivo, sendo estes aços martensiticos de elevada dureza e uma difícil soldabilidade. Este trabalho propôs-se a otimizar os parâmetros de soldagem do processo FCAW (Flux Cored Arc Welding) através da análise do projeto de experimentos (Design of Experiments - DOE) utilizando a Metodologia de Superfície de Resposta (Response Surface Methodology – RSM). Após a determinação dos parâmetros de soldagem ideais, foi realizado a caracterização mecânica e metalúrgica de uma junta soldada com estes parâmetros a fim de certificar-se das propriedades da junta com parâmetros de soldagem otimizados.

Aug 16, 2017

By Mirko Martini, Marcelo Benaglia, Andrea Codalli

Riachuelo Lot 3 forms part of a sanitation programme being implemented in Argentina to relieve the Riachuelo river basin from its current contamination. The programme, by far the most important in its kind in the country during the last decades, will expand the sewage capacity of Buenos Aires and will benefit an area of 4.3 millions inhabitants by intercepting a number of waste water discharges and conveying them to a new treatment plant prior to final discharge into the Rio de la Plata. The project foresees amongst other works the construction of an onshore 48 m deep shaft at the outlet of the treatment plant plus a 4,3 m inner diameter outfall tunnel of 12 km length. The last 1.5 km of the alignment is fitted with 34 vertical risers jacked from inside the tunnel to allow the discharge and dilution of the treated effluent into the Rio de la Plata. This paper describes the peculiarities and challenges, both in terms of design and in terms of construction, of the outfall tunnel, which was entirely bored under the Rio de la Plata using a 5.2 m cut diameter Tunnel Boring Machine (TBM). On one hand, the tunnel segmental lining was designed to work in tension during the system flow rate peaks while on the other the tunnel excavation faced a variety of complex conditions, such as crossing water bearing permeable soft ground formations and advancing at face pressures in excess of 3,5 bars for the entire route.

Jun 13, 2021