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The Kaldo furnace smelting technique was developed for oxygen steel production by the late Prof. Bo Kalling, Domnarvet, Sweden. Development started in 1948, and production in 1956. Five million tons of steel were produced in TBRC's in 1973. Mainly due to high TBRC maintenance costs, the steel industry now prefers non-rotating converters. In non-ferrous metallurgy, however, qualified new applications of the TBRC technique have been realized or are being considered. Inco, Canada, succeeded to convert nickel matte to metal in the Domnarvet pilot plant in 1959, and have now installed a commercial plant in Copper Cliff. La Metallo-Chimique, Belgium, has pioneered secondary copper smelting and refining in the TBRC, operating plants in Beerse, since 1968, and Alton, U.S.A. Peko-Wallsend Ltd., Tennant Creek, Australia, was faced with the problem of producing saleable blister from concentrates containing 1.5-2.0% Bi. The flash smelting matte, containing 0.2% Bi, could not be refined to an acceptable limit of 0.03% Bi in the blister copper in a Peirce-Smith converter. Tests at Domnarvet indicated that a TBRC would achieve satisfactory bismuth elimina- tion. Two TBRC's were installed in Tennant Creek and operated for 14 months during 1974-75. The problems encountered and how they were over- come are described. Further TBRC applications have been studied in Sweden.

Jan 1, 1976

By Godwin Beene

During recent years, copper and acid production from Nkana Smelter has formed a significant proportion of ZCCM's total output, but a number of problems affecting the smelter over the last decade have only been recently overcome. This paper discusses recent developments in the smelting practice, highlighting some of the operational problems experienced and associated solutions. The smelter performance over the decade is discussed and the innovations in the smelting technology employed to sustain production in the wake of limited re-capitalization are dealt with in detail.

Jan 1, 1999

By Geoffrey Brooks, Mehedi Bin Mohammad, M. Akbar Rhamdhani

Molten alkali nitrates are used commercially as thermal storage fluids (HTF) for solar thermal electricity generation. Their range of operation is limited by the thermal stability and this limits the energy (steam-Rankine cycle) efficiency of these processes. In this study, the effect of atmosphere on the thermal stability of nitrates was investigated using simultaneous thermal analysis techniques (STA). The use of oxygen (O2) as a blanket gas was found to delay the decomposition point of the ternary NaNO3–KNO3–LiNO3 (13.23–57.14–29.63 weight ratio) mixture by 55 °C. By which operating range will increase 65 °C more compared to the binary solar salt. Higher heating rates increased the decomposition point but had less effect on premelting and melting properties. Nitrogen monoxide, and O2 evolution after melting indicates concurrent reversible reactions. Similar phenomena were observed for single and binary nitrates. The eutectic melting point of ternary nitrate obtained from the STA agreed well with FactSage eutectic composition prediction.

Mar 1, 2017

By J. Borlée, J. P. Birat

"ULCOS is a large European program launched by a consortium of 48 partners led by arcelor and a core group of steel producers, which was started in 2004 with the support of the European Commission (RFCS and 6FP programs) to search for breakthrough process routes that could, in the future, when fully developed, demonstrate the potential of large cuts in CO2 emissions for the production of steel from iron ore.The timescale for commercial implementation is the post-Kyoto period, i.e. 15 to 20 years from today.The present paper presents the progress made in the first 2 years of this 5 year program.Several concepts are being investigated in parallel: re-engineering of the blast furnace to incorporate CCS in the core of the process, smelting reduction with CCS capabilities, massive use of natural with more CO2-lean technologies than today, hydrogen steelmaking and electrolysis of iron ore. Biomass also offers very attractive perspectives, while raising major challenges.None of these new steelmaking routes are ""no regret"", which means that the European Steel Industry has already incorporated extensive energy saving steps in its present process technology and is working as close to thermodynamics limits as is cinematically and economically feasible, and that decreasing GHG emissions further means introducing breakthrough technologies that add significant costs to the operation of the Steel Mills.They will also require much research and development before they can be proven and implemented commercially.IntroductionThe ULCOS program (Ultra Low CO2 Steelmaking) is a large research program of the European Steel Industry and its industrial and research partners launched in September 2004 to investigate steelmaking technologies that have the potential of reducing the CO2 emission of the Industry by a large amount, typically in the order of 50%. It is supported in the European Community by the 6th Framework and the RFCS programs through 3 complementary European projects [1,2].The present paper summarizes the work carried out in the phase 1 of ULCOS and in framing the program of phase 2."

Jan 1, 2008

By Fang Wu

The paper designs an extraction flow for the total recovery of nickel and cobalt and removing magnesium simultaneously from the cadthodic materials of the spent hydrogen-nickel and cadmium-nickel batteries. The separation of Co, Ni and Mg though P507 extraction .The extraction equilibrium pH is 4.5~5.0, ßNi/Co is 140~180, and ß Ni/Mg is 20~25; nickel and magnesium are scrubbed in two steps, in which the equilibrium pH of nickel and magnesium scrubbing is controlled at 5.0±0.1 and 4.4±0.1 respectively. The stepwise scrubbing technique is adopted to remove 94.5% of magnesium and to recover 99.45% of nickel and 95.35% of cobalt. During the integrated extraction and precipitation process the total recovery fraction of nickel and cobalt are 99.99% and 99.95%, and the recovery fraction of magnesium is 94.02%.The recovered NiSO4 and CoSO4 solution are enriched and crystallized.

Jan 1, 2009

By R. J. Mitchell

Results from investigations into impurity distributions over cathodes are presented with implications for various sampling methods, Selection of an optimum treatment procedure for the test sample is outlined. The impact of both these studies on the development of an in-house method for sampling Isa Process cathode is discussed. The economic compromise actually undertaken, satifying wants and needs to sustain confidence in high grade cathode purity is detailed.

Jan 1, 1987

By Xiang-yang Zhou

Keywords: Low-Grade Dolomite, Low CaO Content, High Specific Surface Area, MgO. A low energy consumption preparation technology of magnesium oxide with low calcium oxide content and high specific surface area from low-grade dolomite has been investigated. The optimum technical conditions for the preparation of magnesium oxide are the followings: dolomite is partially calcined at 750-800° for 2 h; the optimum solid-liquid ratio range in calcined dolomite slurry is 20-30 g?l?1; carbonation temperature, carbon dioxide pressure and end point pH value of carbonation are less than 40°, 0.4-0.6 MPa and 7 respectively during carbonation process; decomposition temperature of Mg(HCO3)2 solution is near 100°; calcination temperature of the precursor (i.e. precipitated basic magnesium carbonate) is less than 850°. More than 90% of magnesium can be extracted by the technology. The MgO product (CaO < 0.38%) with a specific surface area of near 50 m2?g?1 also can be obtained by the technology.

Jan 1, 2005

By Ralph H. Nafziger

The Bureau of Mines, in cooperation with the Idaho National Engineering Laboratory, has electroslag melted a V-5Ti-5Cr alloy using a fused CaF2, flux. The alloy is a candidate for use in future fusion reactors. One objective of this research was to evaluate the feasibility of the electroslag melting process in separating simulated radioactive isotopes from the V alloy to demonstrate recyclability. Small amounts of Ca, Y, and Mn were added as surrogates for radioactive isotopes. Results showed that this vanadium alloy can be electroslag melted satisfactorily. The impurities added intentionally were removed or decreased successfully. Among the major alloying constituents, Cr was retained but there were some Ti losses. The latter may be controlled with process refinements. This research suggests that the electroslag melting process could be a suitable method for recycling V alloys after use in future fusion reactors, or for processing other reactive metal alloys with more immediate applications.

Jan 1, 1996

By H. L. Fraser

A review of the possibilities of performing microchemical analysis in thin sections using a combination of scanning transmission electron microscopy and energy dispersive spectroscopy of x-rays is given. Particular attention is paid to the factors that limit accurate analysis at the highest spatial resolution. As an example of the use of these techniques applied to a potential problem in minerals processing, the identification of iron pyrite and pyrrhotite particles in Illinois, Herrin #6 coal is presented.

Jan 1, 1981

By James Vaughan

Australia is a major miner of ore that requires hydrometallurgical processing. According to the 2016 US Geological Survey Minerals Commodities Summaries, the country is 1st for aluminium (bauxite) and lithium, 2nd for gold, zinc and cobalt, 4th for nickel and silver, and 6th for copper mining, not to mention its wealth in coal and iron ore. In this paper, examples of recent Australian hydrometallurgical activities are summarised. Then, selected research projects from the University of Queensland hydrometallurgy research group are profiled. The projects profiled are related to fundamental aspects of processing bauxite with organics and reactive silica as well as the development of a synergistic hydro- and pyrometallurgical process for copper. The process context and motivation for the research is introduced, key results are highlighted with the associated relevant references.

By T. T. Chen

Kidd Creek continuously-cast copper anodes are characterized by high levels of Se, Pb and Ag; the anode slimes constituents and their morphologies are controlled by both the anode composition and the casting process. Hollow Cu2Se spheroids and tube-like structures, enveloping Cu-Pb-As oxide and/or Cu2O, are present in the as-cast copper. During electrolysis, the selenides are liberated from the copper and accumulate in the slimes layer; the Cu2O and Cu-Pb-As oxide react rapidly with the electrolyte to form soluble species and PbSO4. Silver, which is present mostly as a solid solution in the anode copper, is also liberated during electrolysis and reacts with the Cu2Se to form (Cu,Ag)2Se. The ultimate composition of the selenides in the slimes layer depends mostly on the Ag and Se contents, but various other elements, including Au and Te, are also structurally incorporated. Although the selenides are the major Ag carrier, metallic silver also is present. A thin layer of Cu2O crystals sometimes forms at the copper surface, and may affect anode passivation. Copper sulphate is a common constituent and serves to agglomerate the slimes. Copper sulphate is present on both passivated and non-passivated anodes, but that observed on the passivated metal is present as a thick compact layer. Copper powder is associated with CuSO4.5H2O only on passivated surfaces.

Jan 1, 1987

By S. Yabe

The reinforcement of the annual copper production capacity to 330,000 metric tons has been attained at Saganoseki Smelter & Refinery in 1991, which is one of the largest and most efficient custom smelters in the world. Many operational improvements and technology developments have realized the increase of smelting and refining capacity without adding main facilities to the existing process. The blister copper refining and anode casting process is composed of two 400 tonnes anode furnaces and one double-wheeled casting machine with the capacity of 80 tonnes per hour. The great innovations in this process such as the finding of essential issue on the extending of anode-mould life and the development of a new anode-mould casting machine have raised the operation efficiency by 14% Now, the process is producing 38,500 tonnes per month of best quality anode in well- controlled working condition, and anode productivity per worker increased by 52%. The progress in extending anode-mould life, the mechanism of the new anode-mould casting machine and the increase of efficiency in butane reduction, that were the principal parts of many technological improvements, are described in the present paper, including some operation results.

Jan 1, 1993

By Hector Carreon

This paper presents experimental data for the magnetic field produced by thermoelectric currents around uncracked hard-alpha inclusions in a Ti?6Al?4V specimen under external thermal excitation for different nitrogen content ranging from 1.6% to 5.9%. According to our preliminary results, the magnetic flux density measurements were found to be rather sensitive to changes in nitrogen content with the exception of the intrinsic material background magnetic signal that affected deeply the detectability of inclusions and imperfections in non-contacting thermoelectric measurements. Hopefully, these preliminary results can help identify a non-destructive test method that can detect material inclusions with a level of nitrogen that could be detrimental to Ti?6Al?4V alloy components.

Jan 1, 2009

By Matthew John M. Krane, Christopher J. Vreeman, J. David Schloz

"A continuum mixture model of the direct chill casting process is used to model the transport phenomena and solidification behavior in the Direct Chill casting of an Al - 6 wt% Cu billet using Wagstaffs AirslipTM process. The model, which includes the transport of free-floating solid particles, can simulate the effect of a grain refiner on macrosegregation and fluid flow. Numerical predictions of sump profiles and composition and temperature fields are presented. Two 45 cm diameter billets were cast under production conditions with and without grain refiner. Temperature and composition measurements and sump profiles are compared to the numerical results. The comparison shows excellent agreement for the grain refined case. It is believed that an incorrect model assumption prevents good agreement in the non-grain refined billet. IntroductionDirect chill casting is a semi-continuous process in which molten aluminum enters the top of a water-cooled mold, is cooled, and forms a solid ingot drawn out below (Figure l(b)). The molten aluminum begins to solidify due to the cooling effect of the mold wall. As the ingot is withdrawn from the bottom of the mold, water jets impinge on the surface, directly cooling the billet and forming a solid layer around a liquid melt, commonly referred to as the sump.A particular defect that occurs in a wide range of casting processes, including the direct chill (DC) casting of aluminum alloys, is macrosegregation, the uncontrolled redistribution of alloying elements on the scale of the ingot during solidification. Macrosegregation in DC cast ingots can produce non-uniform mechanical properties [l], which affects the behavior of the metal during downstream forming and heat treat operations."

Jan 1, 2001

By Leonardo Gonçalves Pedroti, Fernando de Paula Cardoso, Beatryz Cardoso Mendes, Afonso Ramos Garcez de Azevedo

This work aims to produce paints using granite waste, as a pigment, and compare their performance to soil pigments based paints, in terms of hiding power and abrasion resistance. Initially, the residue and soils were physically, mineralogically and morphologically characterized. For the production of the paint samples, an experimental model was defined, based on the variation of the proportions of pigment and resin. The proportion of water varied in each sample, in order to maintain the viscosity within a range considered ideal for application. Sequentially, tests were done to determine the hiding power and abrasion resistance of inks. It was found that, in comparison to soil paints, the granite residue paints presented greater hiding power. This result can be explained by the characteristics of the granite residue, which allowed a high nonvolatile content in the mixtures. With respect to abrasion resistance, granite residue paints showed less resistance than soil paints, possibly due to the granulometry of the residue that resulted in a greater roughness of film. In addition, none ink sample satisfied the minimum specifications prescribed in the Brazilian standards for hiding power and abrasion resistance, at the same time. This means that these inks, when used, will require more repair and repainting over time than conventional paints.

Mar 1, 2018

By Dong Liang, Honggang Zhong, Zhenxing Yin, Qijie Zhai

"2507 super duplex stainless steel (SDSS) has been widely applied in a marine environment, attributing to its excellent pitting corrosion resistance and mechanical properties which are particularly determined by the nitrogen precipitation behaviors and volume fraction of ferrite. In this paper, various cooling rates were obtained by applying four different moulds with the common gating system. By which the influence of cooling rates on nitrogen precipitation behaviors and the ferrite fraction in cast 2507 SDSS was comparatively investigated. The results showed that nitrogen porosity could easily precipitate in cast 2507 SDSS under standard atmospheric pressure. The number of nitrogen holes increased with decreasing the cooling rates, and the holes mainly distributed in three zones, i.e. the interface between the horizontal and vertical columnar grains, top vertical columnar grains and the final solidification region. Additionally, higher ferrite fraction was obtained with lower cooling rates.IntroductionDuplex stainless steels (DSS) have a dual-phase microstructure consisting of ferrite (d) and aus-tenite (?). Due to the combined advantageous properties of d and ? phase, their application rapid-ly increased in industry [1, 2]. Super duplex Stainless Steel (SDSS) is the third generation of du-plex stainless steels, of which the alloy elements Cr, Ni and N content are higher than the stand-ard 2205 DSS. Because it has high contents of alloy elements, the SDSS has better mechanical properties, and its pitting resistance equivalent number (PREN) reached a point 43. Hence SDSS has been used in petroleum chemical industry, the marine equipment and harsh corrosion environments [3]. SDSS contains ferrite stabilizing elements, such as Cr, Mo and Si, and austenite stabilizing elements like Ni, Mn and N [4]. Many researchers have studied the effects of these elements on the stabilization of d and ? phase and the ratio of the two phases. High nitrogen con-tent is another prominent feature of SDSS. Nitrogen addition to SDSS is very effective for improving its mechanical properties [5] and corrosion resistance [6], such as pitting resistance in NOx environment. To increase the nitrogen content in steels, a lot of work had been done. N. Nakamura and S. Takaki [7] examined the behavior of nitrogen absorption in Fe-23Cr alloy powder by sintering in nitrogen gas atmosphere, they found nitrogen content easily up to 1.0 wt. %. Using devised NH3 gas injection system, W. Park et al. [8] successfully produced austenitic Fe–23.5Cr alloys containing over 3 wt. % of nitrogen. Further-more, W.P. Tong et al. [9] stated that nitrogen percent was extraordinary high (about 10 wt. %) in pure iron plate. However, the above methods are difficult to be applied to large-scale industrial production."

Jan 1, 2012

By Sven Reutzel

Investigations show that Co-based melts embedded by glass flux in a crucible can be under- cooled nearly as strong as samples processed containerlessly by electromagnetic levitation. This allows to measure magnetic susceptibility on undercooled melts while combining the use of a Faraday-balance and undercooling technique. The magnetic susceptibility of Co and Co-based alloys (such as Co-Pd and Co-Cu) is investigated as a function of temperature from superheated to undercooled state. This is done by measuring the change of magnetic force F, on a sample in a constant magnetic field Bo and an additional gradient field by means of a Faraday-balance. When liquid Co-based alloys are undercooled the magnetisation steeply rises if temperature approaches the Curie temperature. The magnetisation is measured for some Co-based alloys in liquid state as a function of alloy system and its concentration. The results show that the magnetic susceptibility of the liquid undercooled samples follows a Curie-Weiss behaviour, from which Curie temperature and magnetic moments for the liquid state are inferred.

Jan 1, 2002

By Bing Ji Yan, Cui Wang, Ya Peng Zhang, Chuan Hui Li, Hong Wei Guo, Jian Liang Zhang

There are a lot of research of the chlorine element’s influence on blast furnace, and mainly pay close attention to the harm to gas pipes and equipment. There are three kinds of chloride in the blast furnace gas, including HCl, NH4Cl, and NaCl (or KCl, ZnCl, etc.). This paper mainly analyzes all kinds of phenomenon of the chlorine element overflowing blast furnaces in Jinan Steel, and puts forward some different viewpoints, which are that the chloride overflowing out of blast furnace in the types of HCl, NH4Cl, or NaCl (KCl) not only has much to do with raw materials of chlorine load level, at the same time with the blast furnace burden distribution. On this basis, comes up with countermeasures for the different situation, such as adjusting the burden distribution matrix to guarantee the central gas flow smooth and changing the kind of raw materials to reduce the chlorine quantity, which will be helpful to prevent the harmful influence of chlorine element.

Mar 1, 2017

By Zeyun Cai, Gaoyang Song, Bo Song, Yuhou Yang

In this research, super gravity field was introduced in the solidification process of high carbon steel. The experimental results show that the solidification structure of Fe–1 wt% C steel can be largely refined by applying super gravity at the cooling rate of 10 °C/min. Both the primary and secondary dendrite length was markedly reduced. In addition, the eutectic structure in the inter-dendrite was also refined with the obvious reduce of eutectic space. However, the macro-segregation of C along the direction of super gravity was caused with higher weight percent at the upper area than that at the bottom of the sample. The mechanism of solidification structure refinement and the C macro-segregation of Fe–1 wt% C steel in super gravity field were also discussed in this paper.

Mar 1, 2017

By Norbert Hort, Karl Ulrich Kainer, Carsten Blawert, Daniel Fechner

"With the development of new heat resistant magnesium alloys, the automotive industry has introduced several parts to the drive train. The rising number of large magnesium components will result in a higher quantity of automotive post consumer scrap and the changing legislation will force car manufacturers to take magnesium recycling into consideration. So far post consumer scrap has not been used for magnesium alloy production. Quite a reasonable amount of automotive scrap is likely to end up in a mixed light metal shredder fraction. The separation of mixed magnesium scrap according to several alloys is complex. Therefore secondary magnesium alloys made from blended post consumer scrap would be useful. For this work a matrix of potential recycling alloys was prepared by chill casting and high pressure die casting. The materials were investigated for their microstructure, mechanical properties, heat resistance and corrosion properties. The results will be presented in this paper.IntroductionWithin the last ten to fifteen years several heavy magnesium parts have been assembled in passenger cars, such as gear box housings and crank cases [1, 2]. Reasons are the lately developed new heat resistant alloys and the increasing responsibility of automotive manufacturers to reduce the vehicles weight and thereby CO2 emissions. The latter is pushed by international legislation [3, 4]. The rising quantity of magnesium in automobiles will result in an increasing amount of so called post consumer scrap at the end of the vehicles life.So far magnesium recycling was done only for clean scrap that is free from impurities, contaminations and sorted according to a chemical composition or a single alloy respectively [5- 15]. The latter is also called class 1 scrap and mainly consists of sprues and runners from magnesium die casters [15, 16]. For the upcoming automotive post consumer scrap the materials quality strongly depends on the way end of life vehicles are treated. By proper dismantling of old cars, the bigger magnesium components could be collected and possibly treated similar to class 1 scrap [15]. Up to date automotive manufacturers have no uniform recycling system for end of live vehicles. Most probably a considerable quantity of old cars will be shredded. The resulting light metal shredder fraction will contain aluminium and magnesium scrap, both from several alloys. A separation of mixed magnesium and aluminium scrap is feasible according to [17]. Other authors claimed that the grade of separation of magnesium from aluminium is still not sufficient for a proper industrial recycling process of magnesium post consumer scrap [15, 16]. If an automatic sorting is possible it will probably be very expensive [18]. Therefore, so far the main use of post consumer scrap has been the steel desulphurisation and aluminium production [15]. The use of post consumer scrap for magnesium alloy production has been considered already by [15] and [16] but some problems have to be approached."

Jan 1, 2008