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By C. J. Newman

In January 1999, a redesign of the Kennecott Flash Converting furnace settler was initiated to enhance furnace integrity and extend furnace life. This furnace uses Kennecott-Outokumpu Flash Converting technology to produce copper directly from copper matte. A detailed assessment was made of all technology available around the world before making a decision on the design features to be incorporated in the new design. The new design includes the following: redesign of all sidewall cooling elements to include the latest cooling element technology; redesign of the furnace hearth to include a stadium hearth at the reaction shaft end of the furnace; redesign of the furnace hearth to include a stepped hearth design adjacent to the furnace sidewalls; addition of flat settler roof cooling elements .around the reaction shaft; replacement of reaction shaft transition elements with an improved design and improvements to the furnace cooling element monitoring systems. The Flash Converting furnace was shut down on a planned basis in July 2001 to implement these improvements after 29 months of operation, converting more than 1,000,000 tonnes of matte. During the 30 day shut down, the improvements were successfully completed, with furnace start up in August 2001

Jan 1, 2002

By W. P. lmrie

The recent years have seen many copper smelting operations become uneconomic due to a combination of low metal prices, high energy and labor costs, environmental requirements and high investment costs for modernization or replacement. Since a copper commodity requirement remains, the industry will recover, but many operations will need to determine which processes can offer the best prospect for economic operation and readiness for reliable investment and implementation. Corporate investment decisions involve the judgment of many factors in addition to topical technical aspects. Consideration of plant management and operational aspects are thus included. Taking account of such proven processes as conventional, flash and continuous smelting, plus modified conventional and new unproven processes, this paper gives a systematic approach to aid optimum choice for a modernization or grassroots investment. Actual achievements in energy form alternates, conservation and cost effectiveness are highlighted, and areas of remaining potential for energy saving are discussed.

Jan 1, 1983

By Kazuhiro Asai

Hitachi Refinery of Nippon Mining & Metals Co., Ltd. installed a reverberatory type recycling fumace in 1978 in order to treat the industrial wastes which contain metal elements such as copper, gold and silver. Pyrite and industrial waste materials such as galvanizing sludge, hydroxide slime and dust are smelted. Sulfidized copper, iron and precious metals are transformed into matte and other metallic elements are oxidized into slag This copper matte is transported to Saganoseki smelter and copper and precious metals in the matte are recovered. Recently it is difficult to obtain pyrite economically because of the decrease of pyrite production. Therefore, a new treating process of the liquid waste has been investigated at Hitachi Refinery. In this process, the sulfide or sulfate from the liquid waste are smelted as a source of sulfur.

Jan 1, 1997

By Chuanfu Zhang, Jinliang Wang

"Brickless reaction shaft is the latest progress for flash smelting furnace. However, there are many factors influence the melting point of the freeze slag inside brickless reaction shaft, and their variational regularities are not obvious, thus, it is difficult for conventional methods to analyze accurately the complex data. In this research, the experiment data of slag melting point were processed based on optimal discrimination plane. For this method, two orthogonal vectors were firstly built up based on the Fisher's criterion, and then the experiment data were projected onto the two vectors, thus, two-dimensional feature vectors were extracted as criteria to determine the factors effect degree on the slag melting point. Results show that the CaO content is the greatest factor to the melting point of the freeze slag inside brickless reaction shaft, the content of Fe3O4, SiO2, Cu2 O and MgO is the second, and the FeO content is the last.IntroductionBrickless reaction shaft is the latest progress of flash smelting furnace reaction shaft. To research the influence factors on the slag melting point inside the brickless reaction shaft is significant to form freeze slag with compact structure, good heat insulation, certain intensity, appropriate thickness and reasonable distribution, to extend furnace life, to reduce energy consumption, and to promote safe production.However, due to the complex components, there are many factors influence the melting points of the freeze slag inside brickless reaction shaft, and their variational regularities are not obvious. Therefore, it is difficult for conventional methods, such as variance analysis, data fitting, etc., to analyze accurately the complex experiment data.Pattern recognition can easily classify information, even if there are many influencing factors. For pattern recognition, there are some sub-disciplines such as discriminant analysis, feature extraction, error estimation, cluster analysis (together sometimes called statistical pattern recognition), grammatical inference, parsing and matching (sometimes called syntactical and structural pattern recognition) [1, 2]."

Jan 1, 2012

By Benjamin Kohler, Amelinda Olson, Marc Snyderman, Chanaka De Alwis, Mike Lewis, James Cox, Matthew Call, Julia Kluck

UTRS Inc. has developed a novel two-step method to extract commercially viable titanium alloys (patent pending no. 20130164167[1]). This approach has proven its potential to produce a variety of titanium alloys (Ti-6Al-4V,Ti Al ,etc.,) x y and has demonstrated a number of advantages over the current commercial titanium production process. Additionally, the UTRS Process operates without producing CO2 and eliminates the use of TiCl. Step 1: Aluminothermic reduction makes available many types of ores that could otherwise not be used. Due to the aluminothermic reduction technique and the composition of the ore,metal extracted from this step will inherently contain non-titanium elements. Step 2: Electro-refining removes undesirable elements from the thermally extracted titanium. This refined metal has a dendritic morphology with a wool-like appearance that is referred to as “titanium wool”. This new morphology of titanium allows it to have a diversity of endproduct types from titanium powder to bulk titanium.

Mar 1, 2017

By Shinroku Matsuzaki

Data the measurement sensor installed with spatial distribution on the blast furnace were successively accumulated online from the process computer to the database system over a long period. This is a new system that accurately considers the relation with the installation position of each sensor, and picture computerization of the measurement data was developed. The overall operation state of a blast furnace, which skilled operators can see in their mind?s eye, was objectively visualized as pictorial information.

Jan 1, 2006

By Wanderson Silva Rodrigues, Paulo Adão Marinho dos Santos, José Antonio Silva Souza, Luis Alves Venancio, Emanuel Negrão Macedo

"1 AbstractThe production of alumina from bauxite using the Bayer process generates 0.7 to 2.0 ton of the residue known as red mud per ton of alumina. This material has no large scale current use and is usually stored. This paper shows that it can be used in a suspension with water as a gas effluent cleaner with high efficiency to remove SO2. It can substitute other materials currently used reducing the overall environmental impact and potentially reducing the cost of gas treatment.2 IntroductionThe production of millions of tons per year of alumina around the world generates from 0.7 to 2.0 ton of the residue known as red mud per ton of alumina. The vast majority of the red mud is stored in large sealed lakes. Due to the high reactivity this material is considered dangerous and currently there is no operating process capable of reuse all the material produced at any refinery. These lakes after filled of solid material eventually have the surface revegetated. In any cases they will remain as an environmental passive and need monitoring for decades. The search of industrial processes that combine the cleaning of gas effluents emission and reuse of these residues can contribute to the reduction of the overall impact of the alumina production process.The main objective of this work is to study the efficiency of the red mud as alternative raw material for the control of emissions of SO2 in combustion gases. Usually this is made through alkaline solutions of CaCO3 or NaOH in absorbing equipments like spray towers or packed column. This project main objective is to study the reaction of the SO2 with a suspension of red mud and water in order to obtain the basic parameters to design equipment capable of process this reaction on a pilot scale. With that goal compositions of red mud on spray were processed with flow of gas containing SO2 with concentration similar to the exhaust gases of the combustion process of the refineries."

Jan 1, 2011

By P. N. Anyalebechi

The effects of application of steady and pulsed electric current on the cast microstructures of ingots of a 7050 type aluminum alloy have been experimentally investigated over a solidification rate range of 0.1-10 K/s. This involved the application of an electric current of 465-930 mA/cm2 of melt surface area to laboratory-size ingots solidified in a unidirectional manner. Within the ranges of electric current density and solidification rate investigated, the applied electric current reduced the average dendrite, grain, and second-phase particle size. It also made the size distribution of the second-phase particles more uniform. The mechanism for the observed refinement of the cast microstructure by the applied electric current is not well understood. The potential effects of heat-induced local convections, shear stress-induced fragmentation of dendrites, increased temperature gradient due to Joule heating and the thermal and constitutional supercooling engendered by Peltier, Thompson, and Joule heating are discussed.

Jan 1, 2009

By T. Wang, R. G. Reddy

"A new eutectic of LiNO3-NaNO3-KNO3 ternary system was calculated by using thermodynamic modeling and the eutectic temperature was predicted to be 389.15K. The melting point was determined using Differential Scanning Calorimetry (DSC). On repeated measurements, it was found that the melting point of the eutectic composition showed excellent reproducibility with the predicted value. The heat capacity was also measured using DSC and the data as function of temperature were fit to polynomial functions. Subsequently, the thermodynamic properties such as enthalpy, entropy and Gibbs energies of this novel ternary eutectic salt mixture were deduced as function of temperature.IntroductionIn these days, the provision of the large amount of energy required in the peak period relies more and more on the parabolic trough solar power plant and it works by utilizing the thermal transfer fluid. Consequently, the development of inoovative thermal transfer fluid with higher energy storage density is paramount to lower the expense for generating energy [1-4]."

Jan 1, 2013

By Martin Fischer

A new method for the quantitative image analysis of complex microstructures in steel is presented. Microstructures in modern steel grades on the one hand become more and more complex while on the other hand the size of the constituents is scaled down ever further. For these reasons it is increasingly difficult or even impossible to access reliable quantitative information on ratios, shapes and spatial distributions of individual phases and constituents by utilising traditional metallographic analysis methods. The presented new analysis approach is object-based. Its basic processing units are so-called ?image objects? which reflect the pictured structures by merged groups of likely related pixels. By the use of image objects, information on shape, graphical texture and spatial distribution of the microstructural constituents can be processed. With these additional data available, it is possible to quantitatively analyse complex microstructures. This is demonstrated by the application of the method to SEM images of different multiphase steel grades. Because the analysis routine is fully automated, the analysis of large amounts of image data is possible and thereby the investigation of statistically relevant areas of microstructures.

Jan 1, 2009

By J. L. Johnson

The U.S. Department of the Interior, Bureau of Mines, investigated recovery of concentrates containing tin, tantalum, and niobium from the Kougarok deposit on the Seward Peninsula, AK. To date, 25 million lb of tin has been delineated in occurrences containing 0.36 to 1.32 pct Sn, and the resource potential is estimated to be as high as 25 million short tons at average grades of 0.75 pct Sn, 0.025 pct Ta, and 0,025 pct Nb. Deslimed ore was concentrated to 54 pct Sn, 0.3 pct Ta, and 0.3 pct Nb, with recoveries of 74 pct Sn and 44 pct Ta/Nb using a Humphrey's* spiral followed by a Deister shaking table. Tin values in the slimes were upgraded to a 5-pct-Sn concentrate using a Bartles-Mozley separator followed by flotation. The 5- pct-Sn was further upgraded by fuming to give a concentrate containing approximately 60 pct Sn. The recovery of the two products combined was 80 pct Sn and 46 pct Ta/Nb, A flowsheet with mill-design parameters resulted from the metallurgical testing. An economic analysis was made based on the proposed process.

Jan 1, 1990

By E. F. Vegman, Ndabezinhle Dube

"In the practice of conventional sintering, production is always afflicted with the problem of being unable to get a uniform quality of produced sinter in the bed. Invariably the top layer of the sinter cake is composed of weak but highly sinter, while the bottom layer is over-fused, forming a sinter that is very strong but less reducible. These symptoms point to a variable distribution of the heat balance in the process of sintering which results in a deficit of heat in the top layers of the sinter bed and an excess of heat in the bottom layers, due to an increasing input of regenerated heat in the heat balance down the bed. This causes losses in the productivities of the sinter machine and the blast furnace.The current work was designed to improve on the solution to the above problem through the establishment of a more accurate combustion zone heat balance of the sintering process. This development is mostly on the method of determining the regenerated heat input in the overall heat balance. Previous methods were based on the assumption that the width and the velocity of the combustion zone remain constant through out its whole life, which is not the case since tests have shown that both its width and velocity increase as the combustion zone moves down the bed. In this work, these factors have been taken into account. Tests and calculations using the model were carried out for haematite and limonitic ores. The high sensitivity of the model to changes in the sinter mix composition and sintering conditions was demonstrated.The results present the following prospects:• The minimum theoretically possible coke breeze consumption during the sintering of any type of iron ore fines, under any sintering conditions, can be established.• The model can be used to control the metallurgical quality of the sinter in any point in the sinter bed since calculation data includes desired basicity, combustion zone temperature and FeO content in the sinter produced."

Jan 1, 2001

By N. Menad

Thermal treatments of five different types of non-ferrous metallurgical wastes, under controlled atmosphere, were carried out at temperatures lower than 800 °C. The aim of these treatments was to reduce the toxic elements content and to increase that of valuable metals in the residue. <Best results were obtained by their treatments in air or hydrogen or successively both of them. Simple treatments using air or hydrogen of three samples allowed the elimination of more than? 95 % of their toxic elements and&apos; almost doubled their valuable metals&apos; concentration. For the rest two samples, combined treatment was necessary for their efficient decontamination and the concentration of valuable metals, in the treatments residue, to a reasonable value. Most of the solids issued from these treatments can be recycled in .the current non-ferrous metallurgical processes.

Jan 1, 1995

By Gregor Kücher

Lack of basic knowledge on the semi-direct recycling methods for hard metals hinders the application on an industrial scale. However, advantages like reduced expenses and lower environmental impact draw interest at future potentials. Consequently, this report aims to offer insight into the influence of varying bulky hard metal substrates during their lixiviation in acidic media with an oxidant. The statistical software Modde 11 assisted in the development of a design of experiments (DOE) for evaluation of the impact of average grain size, binder and tantalum carbide (TaC) content on the leaching characteristics. The other experimental parameters were constant. Among them were temperature, solution concentration and quantity, duration and substrate surface exposed to liquid volume. Eventually, prediction plots and factors of the computed model equation describe the effects of varying substrate qualities on leached binder metal and selectivity.

By Mansoor Barati

The present paper is based on a term project for final year undergraduate students, requiring them to evaluate a process for producing silicon from rice husk. The traditional method for production of silicon involves carbothermal reduction of quartz in electric arc furnaces at temperatures exceeding 2000 °C. The technology consumes a considerable amount of electrical energy as well as fossil fuels, resulting in significant CO2 emissions. A flowsheet for production of silicon metal from rice husk is laid out in this paper. The technology will consist of combustors, which will generate steam using the rice husk biomass, power generator, and electric furnace for reduction of the rice husk. Materials and energy balance calculations presented here indicate that such process can be operated independent of external electricity.

Jan 1, 2014

By Ian Buterbaugh, Calvin Lo, Tomoko Sano, Brendan Koch, James Catalano, Timothy Walter

In this research, two grades of alumina, one at nominally 85% composition and the other at 99.5% were characterized. Microstructural and phase characterization was conducted using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray Diffraction, and micro-computed X-ray tomography. It was determined that the Knoop hardness values were influenced by the porosity in the 85% composition. Quasi-static compressive tests and high strain rate compression experiments were conducted to determine the influence of the microstructure to the compressive properties. It was observed that the overall compressive strengths increased with strain rate. Although the Knoop hardness values were much lower in the 85% alumina due to the porosity, the compressive strength at both quasi-static and dynamic strain rates were not significantl lower than those of the 99.5% composition.

Mar 1, 2018

By M. Sakamoto, S. Karaswa, Y. Yoneoka, Y. Ohmizo

"The Annaka Refinery has been processing leach residue by Waelz process for 17 years. Recently, the quantity of the leach residue has increased due to a decline in the quality ~f zinc concentrate. Meanwhile, negative factors (e.g. deterioration of water balance due to improved electrolytic power consumption rate) have increased· in the processing of the leach residue.We have implemented various measures in responses to this situation, while striving to increase ·processing capacity and achieve stable operation. AS we have largely completed our assessment of the efficacy of these measures, we report on our recent process improvements.IntroductionWe have been treating leach residue by the Waelz kiln process since 1981. At that time, treatment of only 50,000 tons of leach residue per year was anticipated. However, subsequent process improvements have revised this figure up to 75,000 to 80,000 tons per year.However, today's increased Fe zinc concentrate grade has resulted in increased amounts of leach residue. In addition, improvements have reduced electrolytic power consumption rate of zinc electrolysis, limiting the amount of water that can be used in ·the zinc refining processes and for deaning leach residue. Consequently, we encounter an increasing number of problems and factors adversely affecting leach residue treatment, including increases in water-soluble Zn (WsZn) and. S (S04) in leach residue.To solve these problems, we have taken several measures to ensure long-term continuous operation and treatment of this increased · amount of leach residue. This paper discusses these measures."

Jan 1, 2000

By Kimiaki Utsunomiya, Yasumasa Hattori, Yoshiaki Mori, Toyokazu Okubo

"The effect of various operating conditions on splashing behavior in a Peirce-Smith converter has been investigated with a 1/5.7 scale cold model. Dynamic similarity between the model and a commercial converter was attained by setting the modified Froude number in the model experiments in· the range for normal converter operation. It is known that for a given modified Froude number the dimensionless penetration length of gas into the liquid phase increases as the liquid density decreases. Moreover, penetration· length has a large effect on splashing behavior. Therefore, a heavy liquid, a mixture of water and lead concentrate was used as the liquid phase. It was concluded that the amount of splash dramatically decreases with a reduction in the buoyancy energy per, unit liquid mass and an increase in the horizontal distance between the tuyere tip and the edge of the mouth.IntroductionSubmerged gas injection is widely used in practice in ferrous and nonferrous pyrometallurgical operations to achieve large gas-liquid contact areas and good agitation of liquid for rapid chemical reaction. The common application in ·nonferrous industry is the Peirce-Smith converter with multi-tuyere for copper and nickel matte converting. This process has been used for over 100 years because of its effectiveness in mixing of the molten bath, as well as its merits of the engineering simplicity. However, the mechanisms which · determine the blowing performance is poorly understood, and the design and operating conditions of the Peirce-Smith converter varies widely from plant to plant, such as by diameter, length, mouth angle, tuyere position and level of molten matte. Smelters have continuously made an effort to increase converter productivity, implying maximum tuyere blowing rate. Above a certain critical blowing rate, splash of molten matte from the converter mouth becomes unacceptable because of dangerous ejection and accretion buildup around the converter mouth, which results in interference with effective hood sealing. In fact, a 1993 converter survey[!] reported that splash was a major limiting factor for blowing rate and 54% of responding plants from around the world regard it as a limiting condition[2]. In order to increase tuyere blowing rate a study of the effect of various operating conditions on splashing behavior is expected."

Jan 1, 2000

By WenCai Li, Yong Ren, Shuai Niu, Xin Hong

"Temperature measurement is very important in metal smelting process. Many devices are used to realize non-contact temperature measurements. Compared to conventional thermocouple, infrared temperature measurement has it's unique advantages. However, using an infrared temperature measurement at the top of the furnace can not obtain the desired optical signal because of disturbance from slag layer, high-temperature gases and other effects. A real time thermometry system with dual-wavelength radiation was presented to get optical signal emitted from molten metal through bottom-blowing nozzle. Taking into account the advantages and disadvantages of bottom-blowing devices, a MHP (Multiple Hole Plug) bottom-blowing device was used, through which the optical signal was transferred to the infrared thermometer by use of optical fiber. After conversion and analysis in real-time, the result was displayed and recorded in computer. After calibration, it could be a good predictor of temperature trend in a metallurgical process. IntroductionAt the refining stage of steelmaking, in order to achieve predetermined chemical composition and temperature, high-temperature molten steel is refined in a furnace such as converter. Because the refining process involved with chemical components and reaction velocities in the furnace rely on the temperature of steel, it is necessary to know the temperature accurately in real time during the process. And temperature measurement is also helpful for the end-point judgment. The temperature in the refining process changes quickly, for instance, in a converter, 300t molten steel is processed in only about half an hour.At present, traditional way of temperature measurement is using a thermocouple probe mounted on a lifter called a sub-lance. The thermocouple is immersed in molten steel and its temperature is measured during the short period until the thermocouple is fused. Accurate and reliable temperature can be obtained by this method, but in consideration of the discontinuous measurement and the costs, missing the end-point temperature may sometimes occur.According to the above background, a method in which a temperature-sensing element such as a thermocouple is immersed directly in molten steel is not suitable for the continuous temperature measurement because materials having such stability are not available. Therefore, radiation thermometry is promising. There have been some reports on radiation thermometry through an observation nozzle through the bottom or side of a refining furnace [1, 2]."

Jan 1, 2014

By Takayuki Watanabe, Yoshiki Shimizu, Yusuke Moriyoshi

"B-C-N nanotubes prepared by a flush evaporation method using a de arc plasma were mainly characterized by transmission electron microscopy (TEM) and electron energy· loss spectroscopy (EELS). The nanotubes obtained· were divided into three types such as carbon boron nitride and carbon or carbon nanotubes surrounded with boron nitride nanotubes. These types of nanotubes were obtained at higher temperatures than about 3000 K, however, these were not formed at lower temperatures than about 3000K. On the other hand, 11anocapsules were· formed at all the experimental temperatures and nanocapsules with a homogeneous phase were obtained at lower temperatures than about 3000 K. The effect of additives on the formation of B-C-N nanotubes was not clear. Based on these experimental data depending on temperatures and corresponding microstructures, the formation mechanisms of both nanotubes and nanocapsules were briefly .discussed 1 Introduction As reported previously, nano tubes have unique electrical properties1, 3) The preparations of nallotupes have been usually carried out by flush evaporation methods using either a de arc plasma or a laser4 -5) By these methods the reaction rate is so rarid that we have no data of intermediate products between initial raw materials and. final products of nanotubes 6-9). So, the formation mechanisms of nanotubes have been mainly speculated only from the microstructures of resultant nanoiubes. In order to have more reliable formation mechanisms, it is particularly important to have the information of intermediate products at the corresponding temperatures. From the viewpoints, we have studied about the effects of temperatures on the preparation of nanolubes. Here we report mi firstly some problems on the preparation of B-C-N nanotubes 10), secondly the effects of temperatures on the preparation of B-C-N nanotubes, and finally the formation mechanisms of nanotubes."

Jan 1, 2000