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Upgrading and Removing Phosphorus from Low-Grade and High Phosphorus Containing Iron Ores

Sep 13, 2010

Following extensive trials on a 100 000 tpa Research and Development facility at Kwinana, Western Australia, Hismelt Corporation (wholly owned by Rio Tinto) are confident of the future commercial success of this technology. The Hlsmelt process uses iron ore fines and non-coking coals to produce molten pig iron suitable for feeding to BOF and EAF steelmaking vessels. The unique process configuration combines direct injection of raw materials into the molten iron bath, high rates of metal and slag mixing, and effective post-combustion of the bath gases to achieve efficient coal utilisation. This is the key to the strong economic performance of the process.

Jan 1, 1999

By RENARDIR PEIXOTO MACIEL JUNIOR

A importância do desenvolvimento sustentável, tendo como base um ambiente saudável para as gerações futuras, leva a se pensar em como as organizações poderiam desenvolver materiais menos danosos ao ambiente com boas propriedades e pelo menor custo. A proposta de aproveitamento de fibras vegetais para utilização em desenvolvimento de compósitos de matriz polimérica reforçados pelas mesmas é a motivação da pesquisa visando obter um compósito com melhores propriedades mecânicas e químicas do que sua matéria prima. Por virtude da importância do desenvolvimento desses materiais, a caracterização mecânica da fibra, da matriz e, finalmente, do compósito através de ensaios destrutivos e não destrutivos é fundamental para estudo de sua aplicação. Após a obtenção dos dados, percebeu-se que a adição das fibras melhorou as propriedades mecânicas do compósito resultante. Mostrando, portanto, resultados promissores para o desenvolvimento desses materiais, promovendo assim um material mais barato e de melhor propriedade mecânica, além de uma alta leveza. Em suma, os resultados estão de acordo com o esperado, impulsionando assim um melhor estudo desses materiais, por exemplo, realizando outros ensaios, como ensaios de impacto.

Oct 30, 2017

By Wainer da Silveira e Silva, Marco Antonio Teixeira, Robisom Damasceno Calado, Carlos Alberto Chaves, Tone Takayama Filho

A preocupação com o adequado tratamento de resíduos industriais surgiu com o conceito de desenvolvimento sustentável criado pelo Clube de Roma e contribuiu para o uso racional dos recursos naturais ao longo dos últimos 50 anos. A preocupação com a produção responsável e uso judicioso de recursos naturais priorizou a reciclagem de materiais na agenda das empresas, tornando-se numa atividade de alta relevância, vital para a sustentabilidade econômica e ambiental. Este trabalho aborda os aspectos técnicos, econômicos e ambientais da reciclagem de resíduos contendo zinco através do estudo de caso de reciclagem de resíduos gerados no processo de fabricação de aço em Forno Elétrico, denominado pó de Aciaria Elétrica (PAE). A indústria ainda está em busca de tecnologias para redução da geração e reciclagem desse resíduo. A relevância do estudo está na utilização da Análise Hierárquica de Processo (AHP) para avaliação e seleção da melhor alternativa, entre várias, para tratamento e reciclagem do PAE. Como resultado, demonstrou-se a eficácia do uso da metodologia no empreendimento de reciclagem de resíduos contendo zinco implantado pela Votorantim, em Juiz de Fora, Minas Gerais.

Nov 12, 2019

By V. R. Spironello

The Bureau of Mines is involved in research directed toward the utilization of municipal solid waste. One of the primary objectives is the recycling of the magnetic fraction of municipal solid waste (raw refuse). This is consistent with one of the Bureau's goals, which is to minimize the requirements for mineral commodities by maximizing metals recovery from secondary domestic resources, In this investigation, cupola trials were made using combinations of refuse scrap with shredded automobile scrap under basic and acid slag practices. Furnace operating information and the behavior of alloying and tramp elements was obtained. The research showed that it is possible to utilize up to 60 percent refuse scrap in the cupola under basic practice and 30 percent under acid practice, Aluminum in refuse scrap, present in bimetallic cans, increased the recoveries of silicon and manganese charged to the cupola. Increased use of refuse scrap provided iron of lower sulfur. The alumina resulting from oxidation increased the slag volume. The aluminum and tin contents of the iron increased with increasing levels of refuse scrap in the charge. Lead was not a problem with respect to contamination of the iron. In basic practice, operation of the cupola was satisfactory since all slags were adequately fluid. In acid practice, operation became troublesome above the 45-percent level. Under both practices, the cupola iron melting rate decreased. Particulates in scrubber water and stack condensate samples contained lead, zinc, and tin, and the dust load increased. The tensile and transverse strengths of the iron produced under both practices are reported.

Jan 1, 1980

By Thomas Kuhn, Carsten Ruehlemann, Christina Heller, Anna Wegorzewski

The commercial extraction of metals from manganese nodules on an industrial scale requires more than 50% of the investment necessary to realize manganese nodule mining. This is mainly due to the fact that a completely new metallurgical processing scheme for the extraction of both base metals (Ni, Cu, Co) and high-tech metals (Mo, Li, Ga) has to be developed and upgraded to industrial scale. There are a number of conventional processing technologies that combine hydro- and pyro-metallurgical approaches such as the INCO and CUPRION processes which have been developed in the 1970s and 1980s. Today, new approaches based on selective leaching with chelating agents and bioleaching try to minimize energy consumption and waste production. All of these extraction methods require knowledge how the metals are structurally bound in the manganese oxides. In this contribution we will review the current knowledge about the mineralogy of iron and manganese minerals in the different marine oxide deposits, present our results, and discuss the possible consequences for metal extraction.

Sep 1, 2014

When we are beset with the economic problems the world faces today, we are always inclined to look at the shorter term future. Today I would like to take a long-term view of our industry, project historical demands for our products into the future and discuss opportunities for our members. Perhaps we could firstly look at the long-term demand trends for our metals. If I tend to use non ferrous metals as a basis for my figures it is because this data is more readily available to me. I am sure that most other products of our industry show similar trends.

Jan 1, 1992

By Adriana Amaro Diacenco

Neste trabalho, os procedimentos para modelagem de estruturas de compósitos do tipo sanduíche que incorporam materiais viscoelásticos são apresentados. A análise numérica foi desenvolvida utilizando a Teoria de Deformação Cisalhante de Primeira Ordem (FSDT), que é implementada em um elemento Serendipity retangular contendo oito nós e cinco graus de liberdade. A incorporação do amortecimento para os modelos de elementos finitos em compósitos de placas laminadas é feita usando a abordagem de módulo complexo e a resolução numérica das equações resultantes do movimento são aspectos particularmente relevantes dos procedimentos de modelagem. Após as discussões de vários aspectos teóricos, as funções de resposta em frequências (FRF's) são calculadas para placas laminadas de compósitos com camada viscoelástica.

Aug 17, 2017

By J. Y. Liu

The comminution in a high-pressure roller mill is modeled by an energy-based population balance approach considering three aspects of breakage taking place in the active zones of the mill: the interparticle breakage in the high-compression zone, the breakage at the edges of the rolls, and the pre-breakage in the acceleration zone. Together with an appropriate model of classification, this model can be used to simulate steady-state performance of closed-circuit grindings with high-pressure roller mill. After a brief description of the basic modeling approach, the algorithm of the steady-state calculation for a generalized grinding-classification circuit is presented, from which the circuit configurations commonly met in industrial practice can be derived. With an iron ore as feed material for example, simulation results are shown and discussed in respect of circulating load, specific energy consumption and product fineness for closed-circuit grindings under various operating conditions. The effects of stressing intensity, working gap, classifier parameters as well as circuit configuration on the overall circuit performance are investigated systematically by means of computer simulation.

Jan 1, 2014

By James P. Roe

I. INTRODUCTION. THOSE who deem the subject of this paper an old and super¬seded one may recall with advantage the words of the great proverb-maker, bidding us to seek the new in the ashes of the old. The manufacture of wrought-iron began with the small hearth built upon an eminence, and relying on the wind for blast. Next came, either the hearth about 12 in. in diameter by 2 ft. in height, blown by a man operating two goat-skins for bellows, or, a hearth of greatly varying diameter and about 10 ft. high, depending for its blast upon natural draft. The former appeared in India, the latter in Burmah; and both were in operation until quite recently, though their origin is lost in prehistoric times. The Catalan forge was the evolutionary descendant of the foregoing, and the parent of the Blase-ofen, which in turn led to the high bloomary or " Stückofen," the father of the blast-furnace, as a producer of cast-iron. The production of cast-iron checked the growth of the direct processes; and led to the introduction of various hearths, such as the Walloon, for low-silicon irons; and the South Wales process, combining the run-out fire with the finery, for higher-silicon irons. Some of these are still in operation in localities possessing the necessary raw materials; and their product is used for purposes requiring wrought-iron of exceptional quality, the supply of which is still smaller than the demand. We have to look back but a century and a quarter to see the introduction of the puddling process by Henry Cort; a process which, reinforced by the iron-oxide bottoms and fettling of Hall, was not less revolutionary in character, and more revo-

Jul 1, 1905

By David Hake, David Salisbury

The Drainage Services Department (DSD) of the Hong Kong SAR Government commissioned the design and construction of the West Kowloon Drainage Improvement, Stage 2, Phase 2, Kai Tak Transfer Scheme (KTTS) project in 2000 to relieve potential flooding in Mong Kok caused by the insufficient capacity of the existing storm water drainage system. The KTTS involves construction of a 1.5km,4.4m drainage tunnel and a 450m long box culvert, running from Waterloo Road near Hereford Road to the existing Kai Tak Nullah in San Po Kong. This paper describes the design and construction of; the bored tunnel through both hard rock and soft ground using a slurry Tunnel Boring Machine (TBM), six associated access shafts, a connection structure at Waterloo Road and the box culvert connecting the bored tunnel to the outfall at Kai Tak nullah. Details will be provided on the contractor’s alternative designs adopted during the contract including the use of fibre reinforced shotcrete as one-pass temporary and permanent support for three of the shafts and modifications to the Engineer’s design for the box culvert structure.

Jan 1, 2005

By AIME AIME

LAST month we published (p. 440) the first half of the L discussion by O. E. Kiessling of the paper on copper by Mr. Vogelstein that appeared in the same-issue, but lack of space made it necessary to hold the remainder for this number. Mr. Kiessling now asks to have the last " sentence of the part already published revised to the form given in the first sentence which follows, and also asks that the two parts, though necessarily published separately, be read together, as a mistaken impression may be derived from the first Dart unless it is read in connection with the statement of the Bureau of Mines policy respecting secondary metals which is here published. .

Jan 1, 1931

By Thomas M. Barczak

The intent of this paper is to make mine operators and engineers aware of parameters which affect the loading behavior of passive roof support systems. The strength of a passive roof support element alone is not a meaningful measure of support performance. Passive roof support elements and the surrounding strata act as a system, responding to changes in the physical mine environment due to the extraction of coal and associated redistribution of stresses. The load- ing of a passive roof support element is a function of the stiffness of the roof support structure; a stiffer structure will react a higher load to a converging mine roof than will a more flexible structure. If the stiffness if the support structure is not properly designed, excessive loading will result due to the displacement of the mine roof, causing premature failure of the support. Ideally, the yield strength of a passive support needs to be no greater than that required to support the dead weight of the immediate mine roof, providing the post yield characteristics of the support are compatible with the irresistible convergence of the overburden strata and the support system continues to provide this resistance after reaching its yield load. Idealized design considerations for passive roof support systems in terms load-displacement characteristics discussed. The stiffness and yield characteristics of wood concrete cribbing, as determined controlled tests in the Bureau's Roof Simulator, are compared preliminary recommendations passive roof support utilization also provided.

Jan 1, 1987

By Rong Lu, Hao Wu, Bing Dai, Guoyan Zhao, Li Cheng, Weizhang Liang

Affected by the disturbance of blasting activities, deformation instability and rock dynamic disasters are prone to occur in deep hard rock roadways. Thus, it is particularly necessary to understand the failure behavior of rocks and roadways under dynamic loads. In this study, a series of impact loading tests were carried out on sandstone samples with and without a circular cavity by a modified split Hopkinson pressure bar (SHPB) test system. The mechanical properties and energy evolution of the samples were systematically investigated, and the effect of cavity size was analyzed. The results showed that the presence of the cavity in the samples weakens the dynamic compressive strength by more than 10%, and the peak strain and brittleness are also reduced to varying degrees. Under dynamic loading, spalling cracks occur first on the roof and floor of the cavity, and then different numbers of shear cracks are formed on the sample diagonals. The eventual shear failure mode is the result of the connection of the shear cracks and the cavity. As the cavity radius increases, the dissipated energy density and fractal dimension both grow accordingly, leading to smaller and smaller rock fragments. The dynamic failure behavior of the circular cavity can be well explained based on the dynamic stress distribution law. Overall, this study can provide a reference for the study of the mechanism of rock burst in deep roadways.

Feb 18, 2021

By Hans Chr Andersen

Almost every form of iron ore and carbon material has been used as a raw material in the production of pig iron in electric reduction furnaces. Experience derived from the operation of the large 33,000-kva. Tysland-Hole furnaces, however, indicates that production results are very much influenced by the raw material conditions. The author presents the principle pattern of the metallurgical structure of the interior of an electric pig iron furnace. On the basis of this, he discusses the variations of electrical and metallurgical conditions for the process which will take place with changing raw materials. The formation of a coke bed underneath the electrodes, and its influence on the furnace operation, is illustrated. Quality and grain size of the coke added to the charge will influence the build-up of the coke bed and will thereby also affect the electrical re-''Elektrokemisk A/S, Oslo, Norway. resistance and reduction potential in the furnace.

Jan 1, 1963

By Kerry Lahti, Bryan Ulrich

On Feb. 11, 2005, more than 20 mining professionals gathered in Elko, NV for a day-long round-table discussion on heap leaching. Attendees included project managers, operators and environmental professionals. They represented 10 mining organizations. Knight Piésold sponsored the special event. Its seven representatives included three staff members from the company’s Elko Operation, and one each from its Denver, Cajamarca (Peru) and Vancouver offices. The roundtable format was chosen to allow people from the mining industry to share ideas and experiences in an open forum. Rather than presenting prepared talks, spontaneity was encouraged. This resulted in a lively and enjoyable discussion.

Jan 1, 2005

By Scott Turner

MY YEAR OF SERVICE as president of the A.I.M.E. came at a time when the mineral industry had suffered severely because of disturbed economic conditions throughout the world. The Institute, an integral part of this industry, had been similarly affected. Its membership and revenues decreased; it was confronted by problems of retrenchment at a time when its vigorous operation was especially important to its members, of some moment to the mining industry, and of value to the nation. Throughout the last year, the recession of activity in our industry continued with slight abatement. Your Board accordingly exercised such economy within the Institute as was possible without impairment of essential functions. It endeavored to aid in sustaining the morale of members, their sense of professional unity, and their interest in maintaining research and the interchange of scientific and technologic data upon which the progress of our industry depends. Effort was made to assist in the difficult task of finding employment for needy members; our endeavors have met with some success.

Jan 1, 1933

E. P. Pfleider, University of Minnesota I would like to ask Bob Merrill whether he considers that horizontal concave curvature of a slope has any stabilizing effect, such as Jenike 1 suggested several years ago. R. H. Merrill, U. S. Bureau of Mines, Denver Federal Center The stabilizing effect is due to the restraint offered to radial movement by the curvature. We found in laboratory tests that if we constrained the rock with the same stresses as those measured in the pit then it would sustain a maximum stress about two or four times greater than when the same rock type was unconstrained. We are therefore definitely of the opinion that a constrained situation in a slope is favorable towards stability. G. A. Leonards, Purdue University I was interested in Mr. Lane's observations concerning the correspondence between rate of slide movement with rise of reservoir. Perhaps the most interesting feature is that the rate of movement at the time the rock slope failed was less than the rate at an earlier time when it did not fail. This is difficult to explain from current slope stability theory. K. S. Lane, U. S. Army Corps of Engineers I believe that reduced rate of movement is the result of the progressive type of failure, such as described by Patton and Deere. which occurs along the sliding surfaces. It is difficult to analytically define the progressive failure condition for inclusion in slope stability conditions, but its existence should be recognized in design. We should also realize that many apparently stable slopes undoubtedly contain overstressed regions. To design a slope with no overstressed region would be uneconomical and conservative. D. H. Deere I would pose the question-"What is the meaning of a factor of safety of one?" We were involved in the design of a large, irregularly shaped, underground cavity with an unsupported span of several hundreds of feet. Tests on rock specimens indicated a strength of 1300 lb per sq in. The RQD would have been between 90 to 100 percent indicating excellent structural continuity. In-situ stress determinations indicated an approximately hydrostatic state of stress at a level of 1400 lb per sq in. Calculation of stress concentrations at the walls indicated that the stresses there would be about 3000 to 4000 lb per sq in. Admittedly the rock is in a confined condition everywhere except at the very skin of the wall and the rock walls would thus on the average be somewhat stronger. Allowing for the effect of restraint the factor of safety was found to be less than 0.5 over a region several feet into the wall. Construction was started, using rockbolts only to support the walls. Failure around the immediate skin occurred after each

Jan 1, 1967

By Bill Stormes

This paper will discuss implementation of the Hilti OneStep rock anchor technology to improve face bolting operations during the May 2008 longwall move; increase rock anchor installation capacity; and improve safety by reducing employee exposure periods by utilizing the Hilti OneStep rock anchors.

Jan 1, 2008

By P. Kluge

Mining engineers frequently encounter complex design problems for which the critical components of the design are difficult to quantify or compare. Teams of people typically work on these designs and human perceptions and judgments play a strong role. To assist with this process, the analytical hierarchical process (AHP) as a decisionmaking tool is described in this paper. Although the technique is used in many other disciplines, it is currently not widely used in mining engineering in South Africa. To use the AHP process, the problem should be treated as a hierarchy that defines the goal, the alternatives to reach it, and the criteria for evaluation of these alternatives. Pair wise comparisons are conducted on the criteria of the hierarchy to establish priorities. The value of the technique is that it is simple to test for consistency amongst the pair wise comparisons to ensure that the answer obtained is better than that provided by a random selection. To illustrate the technique, the use of a backfill support system in a platinum mining project was investigated. Ten design parameters, which will be impacted by the use of backfill, were identified and weighted according to their relative importance. The result of the AHP evaluation was that the use of a backfill support system should be preferred to a conventional support system at the mine.

Jan 1, 2011