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By F. W. H. Dean

A very sensitive sensor for the detection and measurement of hydrogen in solid steel is described. This technique is non-invasive and uses a collector to sweep the hydrogen emanating from a steel surface and feed to it sensor. This method is particularly sensitive, resolving fluxes to < 2 pI cm?2 S?I, with a linear measurement up to 1000 pI cm&apos;2 S?I, The collector is held on the steel substrate by magnets and it is shown that emanation of hydrogen from the steel is controlled by bulk diffusion of the hydrogen through the steel. The technique is demonstrated to have an excellent response time and reproducibility.

Jan 1, 2001

By Ruirui Wei, Mingrui Yang, Xuewei Lv

Copper slag is a by-product obtained during smelting of copper from copper ores. In China, for one ton of metal production about 2.2 tons of copper slag was generated, and approximately 15 million tons slag is produced in 2013. Dumping and disposal of such huge quantities of slag will cause environmental and space problems. Most importantly, copper slag cannot be made full use of to maximize its value. In this study, copper slag was used to take the place of scrap iron and part of silica in traditional process and to produce FeSi alloy as the main material. Utilizing silica and copper slag as the raw materials and coke as the reducing agent, FeSi45 was produced in the induction furnace. In addition, the effect of different n(C)/n(O) on FeSi45 has been investigated.Increasing n(C)/n(O) is beneficial to form the stable phase of FeSi. Meanwhile, n(C)/n(O) greatly affects the reduction and recovery of silicon than iron. When n(C)/n(O) equals 1.10, the recovery of silicon and iron is about 77 and 95%, respectively.

Mar 1, 2017

By John W. Ahlrichs

Microscope, electron microprobe and x-ray diffraction have been used to provide quantitative evaluation of products from the mill, smelter, refinery and other metallurgical processes. Phase compositions and their quantities are necessary for an adequate understanding of the various products obtained throughout an operation and in laboratory testing. By careful evaluation, important information can be gained in improving recoveries and increasing grades at various stages of processing. Four case histories are discussed in this paper. Quantitative microscopic counting techniques are applied to mill products to determine degrees of locking and liberation of the economic minerals. Rapid, but accurate evaluation aids the metallurgist to develop or improve the grinding and flotation circuits. In the smelter, the identification and quantification of the phases are important for predicting reaction mechanisms and kinetic trends. Mineralogic techniques have been applied to conventional smelter products, and to those obtained in laboratory tests for newly developed innovations to smelting. Small, but important, values of gold occurrences in ore are difficult to determine. Evaluation of gold usually requires special separations into various mineral concentrates, followed by assays and mineralogic determinations of the products. Numerous occurrences of solid solution constituents can be treated as by-products, but often they are deleterious to metallurgical treatment. Most solid solution problems can be unraveled by the mineralogist&apos;s tools.

Jan 1, 1981

By Marc Liebman

We present the results of a telephone survey of electric arc furnace (EAF) steel producers. This report characterizes the current status of EAF dust generation, treatment and disposal. It indicates the quantity generated, zinc content, other relevant constituents, and plans and trends that will impact on the quantity and characteristics of the dust generated. The survey covers EAF based steel producers in the United States and Canada. It identifies the processors currently employed, opinions about the use of these processors and services, as well as new technologies being considered.

Jan 1, 2000

By Xia Zhao, Yong Zhao, Wen Pan, Ze-jun Ma, Yan-juan Yang

Characteristics of the gas-solid reduction reaction between iron ore sinter and carbon monoxide (CO) gas at 1273 K were studied with thermogravimetric analyzer. The microstructure, mineral compositions and porosity of sample were investigated prior to reduction, in the 30% reduced sample, in the 70% reduced sample, and in the fully reduced sample. At the reduction degree of 30%, the hematite and calcium ferrite was reduced to 44.4 and 60.4% respectively. At the reduction degree of 70%, all the hematite, calcium ferrite and magnetite were reduced to metal iron, only 36% wustite was left in the core area. The reduction reaction began with the loose structures and spread to the nearby area. In the area of micropores, the reducing gas can easily diffuse to the reaction interface to proceed the reduction reaction effectively. So increasing the content of micro-pores is an effective way to improve the reducibility of the sinter.

Mar 1, 2018

By Katsunori Yamaguchi

A new technique for the removal of tramp-elements from steel scrap has been required from the viewpoint of saving energy and protection of environment. In order to obtain fundamental information on the removal of copper, tin and zinc from molten iron, the extraction method by using of phase separation in the liquid Fe-Pb-C system was investigated at 1453K A mixture of iron, lead and carbon melted in a carbon crucible separates into two phases of lead and iron containing carbon. The compositions on the miscibility gap in&apos; the Fe-Pb-C system are 95A%Fe-4.5%C-0.l %Pb and 99.9%Pb-0.1 %Fe. The distribution ratios of copper, tin and zinc between the lead and the iron phases, Lx=[masso/uX in molten Pb]/(masso/uX in molten Fe), are 2.2, 2.2 and lA, respectively. Seventy percent of copper and tin from iron scrap can be eliminated with comparable lead addition. Gold, silver and palladium are enriched in the lead rich phase, on the contrary platinum and rhodium are more distributed to the iron rich phase than to the lead phase.

Jan 1, 2003

By Guan-Yong SHI, Cong Wang, Zhi-he DOU, Ting-an ZHANG, Shi-gang FAN

Based on the pre-works, this paper proposed a new short stage process of the intensify aluminothermy reduction by the stage to prepare high titanium ferroalloy with low O and Al contents. We investigated the effects of Al and Ca and Si combination reduction agent, slag type and step-up reduction conditions on the Al content and distribution in the alloy. The results show that the step-up reduction can not only reduce effectively the oxygen content in the alloy, but also reduce effectively Al content. For instance, the oxygen content in high titanium ferroalloy is within 1%~4%, and the Al content is within 1%~5%. Its quality reaches the requirement of high titanium ferroalloy prepared by remelting process.

Jan 1, 2015

By David Melgaard

A significant emerging recycling, waste minimization problem stems from legacy waste from the nuclear weapons program and from production of power using nuclear fuel. Premium quality metals used in nuclear plants become contaminated, making them unsuitable for reuse. Consequently, decontamination studies were conducted to evaluate the decontamination capacity and partitioning effeetiveness of Electroslag Remelting (ESR). Eight laboratory melts were conducted to evaluate the efficacy of using ESR to transport radionuclides from the liquid metal phase to the liquid flux or slag phase. To determine the decontamination effectiveness, several surrogate compounds for uranium, plutonium and other fission products were added to the melts. During the melts, the melting rate was varied, typical slag additives were used, and two different slag compositions were evaluated. The resultant post-test ingots and slag were then analyzed to determine the partitioning of the surrogates. ESR generally proved very effective in removing contaminates from the metal with a few noted exceptions. -

Jan 1, 2003

By Yasuo Ojima

The mainstream of copper smelting processes in the world today is a combination of Outokumpu type Flash smelting and PS (Pierse Smith) converting process. Presently it can be estimated that about 50% of the worldwide copper production is produced by the Flash smelting process and 80% by the PS converting process. PS converting process due to its operational flexibility and despite its batch character of operation has been widely used in many smelters for more than 100 years. However, an environmental issue has been pointed out related to this process because of the difficulty of handling the fugitive gases. Recently several copper smelters in the world have been newly construeted and others have executed major modification and modernization. The continuous converting process has been applied in many of them instead of PS converting process. This paper compares PS to the emerging continuous converting process and makes a prospect of the future of the copper converting process.

Jan 1, 2003

By Carla Lupi

Zinc electrowinning from sulfate solutions is the traditional industrial method to produce SHG zinc. Over the past few years several efforts have been done to improve process efficiency in order to reach high productivity with low energy requirement. The latter aim can be pursued both by means of a hard purification of the electrolyte and reducing the anodic voltage. This work is a comparative study of the results obtained in several previous researches on zinc electrowinning from both sulfate and chloride solutions. Zinc electrowinning tests on industrial sulfate solution have been carried out by using Pb alloy anodes and by adding organic depolarizers such as ethanol, acetic acid or ethylene glycol. Experiments on chloride solutions, obtained by purification of zinc exhausted electrolyte, have been performed by using DSA anodes and by testing the effect of additives such as TEACI and TBAC\. Comparing the best results obtained with the two methods it can be highlighted that a high quality zinc is electrowon in both cases with comparable energy requirements.

Jan 1, 2000

By Fernando Aracati Botelho, Jose 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 and about 800 kg of CO2 per ton of alumina. The direct use of exhaust gases to react and neutralize the bauxite residue may allow a double gain: open a wide range of new applications for bauxite residue reducing its reactivity and sequester from 3 8 to 107 kg of CO2 per ton of alumina. This paper shows a pilot scale reaction of a suspension of bauxite residue-water with flue gas produced from direct burning oil, similar to the exhaust gases of a refinery. Two different types of reactors are used, a spray tower and a packed column. The inlet and exhaust gases are analyzed using electrochemical cells and non-dispersive infrared sensors. The pH of the suspension is monitored during the reaction and after to evaluate the buffer effect. 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 (RM) 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 reusing all the material produced at any refinery. These lakes after filled of solid material eventually have the surface revegetated [4]. In any case they will remain as an environmental passive and needs monitoring for decades. The search of a industrial process that combines the reduction of the CO2 emission and the reduction the pH of the red mud opening the possibility of large scale and economically viable ways is the main objective of this work.The use of the exhaust gases of the refmeries to neutralize the bauxite residue may allow a double gain: Open a large array of new applications for the residue with the reduction of its reactivity and sequester millions of tones ofCO2 plus other gases like SO2 [7] and NOx. This project studies the reaction of the exhaust gases from a boiler burning diesel with RM in different reactor types and conditions in order to obtain parameters to design equipment capable of process this reaction on a larger scale. With these objective compositions of red mud were processed with flue gas at concentration similar to the exhaust gases of the calcination process and boilers of the refmeries."

Jan 1, 2012

By Bruce H. Baker

Studies of used or unused refractory materials are excellent examples of applied mineralogy in industry. Refractory materials are mineral substances containing ceramic or chemical bonding systems. Knowledge of the mineral composition, bonding, and textural relationships often explains the resulting physical property values of a refractory and contributes to the interpretation of refractory wear mechanisms occurring in steel plant service.

Jan 1, 1982

By W. L. Dalmijn

Glass recycling in the Netherlands &apos;has grown fr.om 10.000 to 300.000 tonnes per annum. The various advantages and problems of the glass cycle with reference to the state of the art in the Netherlands is given. Special attention is given to new technologies for the automated sorting of cullet with detection systems. In Western Europe the recycling of glass has, become a success story. Because of this, the percentage of ,glass cullet used in ,glass furnaces has increased. To meet the quality demands of the glass industry, automated sorting for the removal of stones, non-ferrous metals and other impurities ,had to be developed and incorporated in glass recycling plants. ;In Holland, Germany and other countries, the amount of glass collected has reached a level that colour-sorting becomes necessary to avoid market saturation with mixed cullet. Recently, two systems for colour-sorting have been developed and tested for the separation of bottles and culletin the size .range of 20 -50 mm. With the increased capacity of the new glass recycling plants, 120,000 -200,000 tpy, the quality systems have also to be improved and automated. These quality control systems are based on tile automated sorting technology developed earlier. for the glass recycling plants. The data obtained are automatically processed and printed. The sampling system and its relation to the theory of Gy will be described. Results of both developments in glass, recycling plants will be described.

Jan 1, 1995

By Lori Bassman, Cassandra George, Cullen McMahon, Md. Zakaria Quadir, Michael Ferry

"Complete and accurate analysis of subgrain microstructural features must include three-dimensional information. Three-dimensional electron backscatter diffraction (EBSD) data can be used to characterize these features; however their boundaries first must be determined. This cannot be accomplished simply with pixel-to-pixel misorientation thresholding because many of the boundaries are gradual transitions in crystallographic orientation. Fast Multiscale Clustering (FMC) is an established image processing technique that we have combined with quaternion representation of orientation to segment this kind of data. Segmentation algorithms often have issues handling images with both distinct and subtle boundaries. Our implementation of FMC addresses this by using a novel distance function and statistical analysis to take into account the variance in orientation of each feature. Although FMC was originally a twodimensional image processing algorithm it can be generalized to analyze threedimensional data sets. As an example, a segmentation of microbands in cold-rolled aluminum is presented.IntroductionThree-dimensional electron backscatter diffraction (3D-EBSD) is a method for mapping the local crystallographic orientations of points in a volume. The technique uses a dual beam platform consisting of a focused ion beam (FIB) and SEM with EBSD, where FIB is used for serial sectioning and EBSD for orientation mapping of 2D slices. These 2D slices may then be stacked to create a 3D volumetric data set.Typical uses of such a data set include characterizing the geometries and crystallographic orientations of surfaces between structures in 3D [1-5]. This involves identifying boundaries accurately, either in 2D slices with subsequent 3D reconstruction (as illustrated in Figure 1) or in the 3D data set. All such data sets present the challenges of i) aligning data slices to correct for instrument drift, ii) identifying relevant boundaries, and iii) implementing appropriate smoothing or interpolation algorithms. The focus of this paper is boundary identification."

Jan 1, 2011

By Caisa Samuelsson, Taishi Matsushita, Hannes Holmgren, Sina Mostaghel

"Rönnskär Smelter of Boliden Mineral AB, Sweden, is a large end-processor of secondary raw materials and waste, including electronic scrap. Electronic scrap may introduce various impurities to the smelter's flow-sheet, among which alumina is a common and significant one. This article summarizes the results of an ongoing research at Luleä University of Technology, Sweden, to study the influences of alumina on different properties of slag from the zinc fuming process at Rönnskär smelter. A combination of different experimental techniques and thermodynamic calculations have been used to investigate properties such as density, surface tension, effective thermal diffusivity, viscosity, and melting/leaching behaviors. Results show that the addition of alumina to this slag increases the degree of polymerization of the melt, and physical properties vary correspondingly. Mineralogy of the semi-rapidly solidified samples is also changed due to alumina addition. A correlation between mineralogy and leaching behavior can be observed.IntroductionBoliden's Rönnskär Smelter is a base- and precious-metals producer located in north of Sweden. Its main products are copper, zinc clinker, lead, gold, and silver. Sulphuric acid, liquid sulphuric dioxide and iron sand (granulated slag) are some of its main by-products. In order to optimize the overall outcome of the process, different refining units are integrated in the smelter's flow-sheet (Figure 1). Copper concentrates and fluxing materials (mainly silica sand) are charged to the process. The produced matte is sent to the converter and the generated slag is charged to the fuming furnace, where it is treated by reducing gases to produce zinc clinker. The converter's slag is charged to the electric furnace, while the fumed slag is tapped into the settling furnace for further cleaning, where matte, slag and speiss (residual metals) are separated. The matte from the settling furnace is also sent to the converters; its speiss is sold to external customers; and its slag is water granulated and sold as construction material, which is known as iron sand."

Jan 1, 2012

By Yuri Gelfgat

"The report presents the results of theoretical and experimental investigations of the MHD method used for production of composite materials from immiscible melts, e.g., Al-Pb, Zn-Pb, Bi-Ga and others, which, when solidified, can be presumed as ""frozen emulsions""IntroductionThe searching of the methods for controlling the phase distribution in various liquid heterogeneous media is one of urgent tasks in modem material science. The studies [1-3] have revealed that in case of electrically conducting media the influence of electromagnetic body forces on the liquid can be a rather effective mean of such a control. The current paper investigates some physical conformities governing the behaviour of binary liquid metal systems with a immiscibility region under electromagnetic processing designated to produce ingots with homogeneous structure.The main idea of the proposed method rests upon a concept that the electromagnetic forces in the melt are similar to gravity forces due to buoyancy effects in space and have a selective ability to influence the melt components dependent on their conductivity. In crossed electric E and magnetic B fields (fig.I) each component of the medium is influence by the force density f = jXB, where the current density j is determined by the conductivity a of the component j = -oE. When this force is directed parallel or non-parallel to the gravity vector, the buoyancy of suspended particles can be controlled accordingly.This phenomenon allows one to create a situation in binary system, when the sums of all mass forces (gravity and electromagnetic) affecting every component are equal, and two components are under conditions of equilibrium with respect to each other. These conditions are called quasiweightlessness, which is generated in the melt by the electromagnetic forces."

Jan 1, 1998

By Ender Keskinkilic

Continuous casting of slabs is conducted with two successive steel flows: first from ladle to tundish, then from tundish to mold. There are certain process abnormalities related to ladle, tundish and mold. For example, change of submerged entry nozzle (SEN) is the one encountered during steel flow from tundish to mold. Tundish exchange is the abnormality taking place due to replacement of processed tundish with the new one at rest. Another example is the flow of steel from ladle to tundish without a ladle shroud. In this study, a statistical analysis was conducted related to the process abnormalities in slab casters of a steel plant. Slab surface defects observed in slab yard was incorporated in this analysis.

Mar 1, 2018

By D. P. Cook, Jr. Jones, J. W. Evans

"It is well understood that the flow of liquid metal in the mold region of the caster can have a notable effect on the overall solidification behavior in aluminum casting. Previously our group has characterized the flow in this region in a water model, using particle imaging velocimetry. The flow is significantly effected by the specifics of the metal delivery system, i.e. size, geometry, used during the cast. Recently, a time-averaged 3D numerical model of the nozzle, combo bag and sump region has been developed and its validity has been tested against experimental data. Cases were run for different sized combo bags as well as bags that have been blocked. The results show satisfactory agreement between the physical and mathematical models.IntroductionFluid flow in the head of an electromagnetic (EM) and direct chill (DC) ingots has been shown to effect many important operational parameters in casting such as superheat removal, macrosegregation, and hot cracking. In most cases, the momentum from the nozzle is diverted through a delivery system, termed a bag, before entering the mold region. The specific geometries of the bags vary widely from operator to operator suggesting that there is still some question as to the optimum design. Several studies [1-4] have been carried out to understand the influence of the bag design on the solidification behavior in aluminum casters. However, few studies have included numerical prediction with experimental verification. Unfortunately, many simulations performed today still do not accurately account for flow in such devices.Recently, a significant amount of research into the flow resulting from the metal delivery systems has been performed [5-8]. The thrust of this research has been characterizing the flow patterns by a measurement technique called particle imaging velocimetry. The data suggest that the method of delivering the liquid metal into the mold region has a significant effect on the nature of the flow. With a detailed set of quantitative data from a water model, a numerical model can be built and tested to ensure a proper description of the flow field. The computational model used in these simulations is designed to represent a laboratory scale model of a caster in which ""combo"" bags were simulated. Such bags are mostly of a densely woven glass fiber material with low permeability to aluminum. ""Windows"", of a more open weave, permit aluminum to flow from the bag, see Fig. I. Two different sized combo bags were modeled, each subject to two different outflow window configurations. Furthermore, experimental measurements [9] were used to validate the model results."

Jan 1, 1999

By Mark Kramer

This paper is limited to treatment of bottom and fly ash waste resulting from WTE and RTE Cogeneration plants, commonly known as trash burners. The body of the paper defines waste generation and conventional treatment schemes. This paper does not identify a best treatment, however, it does offer a general perspective of the treatments to lead the reader to further investigation. Advantages and disadvantages of the ash treatments Is discussed in each treatment section.

Jan 1, 1996

By Susanne Pignolet-Brandom

QEM*SEM is an automated scanning electron microscope/computer system that characterizes samples with regard to mineral modal abundances, mineral grain and particle sizes, mineral associations, and particle surface areas. Additional information, based on the classification of particles according to the area percentage of a mineral of interest, can be obtained for samples of particulates. QEM*SEM is capable of analyzing a wide variety of materials although it was originally developed for applications to the minerals industry.

Jan 1, 1988