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By Vera Lúcia Othéro de Brito

Literature has shown that spinel Co-Mn ferrite have potential application in magneto-mechanical sensors, due to its relatively high magnetoelastic sensitivity. In this work, Co-Mn ferrite was processed by means of the ceramic method, using Fe2O3, MnO and Co3O4 as raw materials. Samples were liquid-phase sintered, using Bi2O3 additive as liquid-phase former. X-ray fluorescence analysis was carried out in the raw materials in order to evaluate their impurity content. Atomic absorption spectrometry analysis was used for quantifying the Co/Mn/Fe proportion in the ferrite. The microstructure of the sintered sample was analyzed by means of Scanning Electron Microscopy. The magnetization and magnetostrictive behavior of the ferrite were evaluated, obtaining curves for magnetic hysteresis, magnetostriction and magnetoelastic sensitivity. The impurity inclusions and the Bi-rich particles formed from the liquid phase were characterized. The sintered ferrite had a total magnetostriction of -126ppm, which is lower than the values reported in literature for a Co-Mn ferrite of similar composition. It was verified that sintering was carried out within a critical temperature range, in which the decomposition of Mn ferrites may occur when sintering in air. This decomposition affects the magnetic properties of the material, and it may be avoided by using controlled sintering atmospheres.

Aug 8, 2018

By José Roberto de Olveira, Anna Paula Littig Berger, Caio Vaccari Silva, Victor Bridi Telles, Felipe Fardin Grillo, José Roberto de Oliveira

No presente trabalho foi proposto uma análise da eficiência de desfosforação de uma mistura padrão M1 e outras cinco misturas, onde foi realizada variação da massa de mistura adicionada ao sistema (60,70 e 80g), temperatura de trabalho (1350ºC e 1350ºC ajustada) e metodologia de adição. Os testes experimentais foram realizados a uma temperatura de 1400°C, com agitação de 450 RPM, em um forno de resistência. Para a análise das propriedades da escória, foram realizadas simulações através do software de termodinâmica computacional FactSage 7.2 e análises de imagens obtidas da superfície do cadinho ao final dos experimentos no software Quantikov. A mistura M1 apresentou melhor desempenho do que as misturas em todas as situações estudadas, sendo observado que melhores condições experimentais foram a utilização de 70g de mistura, a uma temperatura de 1400ºC, com a metodologia padrão de adição de toda a massa da mistura no início do experimento.

Oct 1, 2019

By Franz Reufer

At Rogesa in Dillingen, Germany, a joint venture company of AG der Dillinger Hüttenwerke and Saarstahl AG and at Salzgitter Flachstahl GmbH in Salzgitter the sinterplants are equipped with the Paul Wurth EFA™ process for the final sinterplant off-gas cleaning. In Dillingen two and in Salzgitter one EFA™ plant are in operation at the respective sinterplants to comply with the very stringent environmental rules prevailing in Germany according to the German Clean Air Act called “TA Luft”. The main target is to eliminate or reduce emissions like dust, sulfur components, dioxins/furans and others in the sinter process off-gas. Since 2006 and 2011 the two EFA™ plant are in operation at Rogesa while the EFA™ plant in Salzgitter was also commissioned in 2011. These installations significantly contribute to the improvement of the emission situation of the Dillingen and Salzgitter Works. The EFA™ technology is the state-of-the-art process for such kind of application in terms of additive and energy consumption, reliability and availability. The report gives an overview of the EFA™ process and the performance results of the Dillingen and Salzgitter plant.

Aug 1, 2018

By Paul Riches

Today’s steel producers face the dual challenge of ensuring on-time delivery and ever demanding product requirements, while also running a lean operation. Every day the management of a long rolling plant requires continuous optimization of both operating and business practices. Imagine a long rolling facility, where individual pieces of equipment communicate with each other, where sensor information can be used not only for control purposes but to also monitor the condition of the equipment, where models are used to verify the process is within working limits and the equipment raises alerts to operators when it requires maintenance! Utilizing the ongoing evolution in technology though data collection, communication, internet of things, control techniques and smart sensors, there is now more information available than ever before. The collection and analysis of this information will both advance control and monitoring of plant performance; revolutionizing long rolling mill plants worldwide and optimizing the entire value chain, along with improved and more flexible production.

Oct 30, 2017

By Marcela Gotelip Barbosa

Pellets are the main iron input to the blast furnace at ArcelorMittal Lazaro Cardenas iron and steel making facility in Mexico. Pellets are made at this facility using the concentrates generated and shipped from their captive mines viz., Las Truchas, Pena Colorada, Volcan Sonora. The concentrating plants, after grinding the ore to the liberation size, use magnetic separation and flotation to reject the silica, sulphur and phosphorous impurities. At Volcan Sonora Mines, the ore is contaminated with phosphorous minerals, and hence, after magnetic separation, the phosphate minerals are floated using anionic carboxylate collector (sodium oleate). Apart from floating the phosphate minerals, the sodium oleate also has some tendency to smear on the iron bearing mineral surfaces leaving a hydrophobic surface, which is expected to reduce the green pellet strength due to absorption of ultrafine sized air bubbles on these surfaces, and further generate higher levels of dust during the induration process. In order to alleviate this industrial problem, comparative studies were carried out on the concentrates from magnetic separation using reagents from synthetic sarcosinate and carboxylate family collectors. Results have indicated that the sarcosinate family members not only were found as replacement to carboxylate collectors, but also reduce the phosphorous content below the values achieved with oleate, thus have considerable benefits in the downstream steel making process. Based on the results, plant runs are being taken up at Volcan Sonora. In this article, the laboratory results obtained on iron grades and recoveries, and phosphorous rejection using both the reagents are presented.

Aug 1, 2018

By Paulo Masiero

Sintered titanium carbide has been extensively used since the early 1980s for demanding wear-resistant applications and, in particular, in environments characterized by high temperature and oxidation. Thanks to its physical characteristics, especially its low density, titanium carbide (TiC) has been successfully applied in the manufacture of cassette guide rollers for hot steel rolling. However, the peculiar characteristics of the sintered Ti carbides make it difficult their redressing and hence this has always represented the limit for a more extensive application. Very often iron based alloys are preferred even if, in general, they are less cost effective just because they are easier to be redressed by turning. The availability of a simple, compact, fully automatic and reasonably priced CNC machine; specialized in the grinding of guide rollers and able to operate accurately and efficiently -both in contour and in plunge- can definitively solve TiC’s redressing problems and render its use even more widespread and attractive.

Oct 30, 2017

By "Andreas Steinwandter

The demand for increasing energy efficiency and CO2 reduction is one of the global megatrends of our time. Although the steel industry suffers from a volatile economic environment, the steel plants are interested to find opportunities for sustainable cost reduction and put efforts into healthy solutions for the environmental. Integrated steel plants are trying to cut electrical power and energy costs as these are among the biggest cost factors that can be influenced and taking all the advantages they can. For the integrated iron and steel making route the interaction of waste energy utilization along with process energy demand, natural and metallurgical gases, steam and heating systems as well as power generation has to be considered. Potential energy sources, such as sinter plant, basic oxygen furnace (BOF) cooling stack or reheating furnaces are considered in order to elaborate an integrated energy concept. Especially electric power generation is an attractive option for steel plant operators since it can easily be connected to the existing power grid of the steel plant. When direct local use of waste heat is limited, the best option is to convert it to mechanical/electrical power with a Rankine Cycle. A stand-alone system, compact design with minimum operational costs in order to fit into the existing steel plant layout, are the main requirements of such units. The objective of this paper is to demonstrate economic feasible opportunities for energy recovery for sinter cooler and basic oxygen furnace with focus on electric power generation via ORC modules taking at the same time advantages of CO2 reduction by utilizing waste heat from the process. Furthermore typical arrangements and layouts of such solutions as well as basic economic calculations will be presented in the paper.

Oct 30, 2017

By Andrew Slifka, Pello Uranga, Douglas Glenn Stalheim

Structural steel final mechanical properties of strength and ductility are predominately generated by the final ferrite grain size/packet size and homogeneity of that ferrite grain size/packet size through the cross-sectional area. Forty to seventy percent of the strength components come from how fine the final cross-sectional ferrite grain size/packet size that can be produced.[1] All the ductility properties of structural steels for a given microstructure are predominately driven by how fine AND homogenous the final cross-sectional ferrite grain size/packet size can be refined.[2,3,4] One key ductility property of structural steels used in construction and energy transmission applications is fatigue. Both low and high cycle fatigue can be realized in these end applications, however, low cycle fatigue is typically the predominate mechanism. In construction applications the environment for fatigue is typically air, such as in wind towers or high-rise building construction. In energy applications, there is an interest in high pressure (5.5 – 21 MPa, 800-3000 psi) gaseous hydrogen as an alternative fuel source to fossil fuels. A project to study the effect of the cross-sectional grain size/homogeneity of a relatively pure polygonal ferrite microstructure on the fatigue performance in air and high-pressure gaseous hydrogen has been developed. This paper will discuss the project strategy, microstructure developed for the project and initial test results.

Oct 1, 2019

By Norbert Asamer, Stefan Purrer

Depending on the product or the material grade, conventional deburring machines, such as e.g. with rotating hammers, are in many cases not capable to reliably or completely remove burrs from the edges of a continuously cast product. Burr, however, is generated at the front and/or tail ends of a slab, bloom or billet as a result from torch cutting. Likewise, traversal grinding of the slab’s rolling surfaces can also cause burr at the long side edges of the slab whereby such burr can even be more difficult to remove. Based on their experience and know-how with abrasive machining processes (abrasive cutting, high-pressure grinding) over a period of more than 50 years up to now, BRAUN has developed a highly flexible deburring grinding machine for applications which are too difficult for conventional deburring techniques. BRAUN’s deburring grinding machines were successfully introduced to the steel industry and have proven their worth under normal production conditions already. The subject paper describes the key features and advantages of BRAUN’s machine design and the operational results from the first already completed projects.

Oct 1, 2019

By Johanna Alegría-Ortega

Cr/CrN bilayer coating was deposited on AISI 440C by Cathodic Arc. The composition and structure of the Cr/CrN coating were investigated by scanning Electron Microscope, X-Ray Diffraction and X-ray Photoelectron Spectroscopy. The results show that crystal structure obtained was CrN phase with preferred [220] orientation. The hardness and adhesion of coating also were studied. The evaluation of erosion-corrosion (EC) on 440C bare and coated with Cr/CrN was performed by carrying out wear tests using a slurry jet with impingement angle 90° at 4 and 8 m/s. Corrosion, erosion and synergism wear rate were evaluated following the procedure described in ASTM G-119-09. This study presents that the synergism wear rate exceeds 40% of the total mass loss for coating and 60% of mass loss for the 440C, being the most aggressive wear component. The increase in impact velocity generated a rise in mass loss for both 440C bare and coated. The Cr/CrN coating offers better corrosion and erosion–corrosion resistance under all the tested conditions.

Aug 8, 2018

In today’s competitive steelmaking environment, the optimization and continuous supervision of the blast furnace process is of major importance. Modern probes and process measurement systems can assess the specific operation of the blast furnace. They provide a better and detailed process understanding and control. The benefits are even more important when they are combined with process models and expert systems. Everyday operation, productivity and even the lifetime of a blast furnace can be significantly improved by collecting, interpreting and acting upon such process data correctly. Only a comprehensive knowledge of the various process phenomena together with measurement of process variables inside the blast furnace enables the operators to optimize coke and fuel rates, to run the blast furnace smooth, reliable, and safe, and to make best use of the available raw materials. While the improvement of the blast furnace process with respect to productivity remains the main task, also, the timely identification of abnormalities and the assessment of process variations is an objective. This paper describes the blast furnace measurement systems that are available for everyday automatic use and provides an understanding for the possibilities of modern probes. The different applications are daily blast furnace supervision, charging process optimization, and observation of the internal state. Finally, the paper gives recommendations on probe configurations for different blast furnaces sizes, considering both a technical and an economical point of view.

Aug 2, 2018

By Antonio Esposito

Saving energy and reducing pollution by minimizing emissions are today great challenges in the coking industry worldwide. In order to achieve satisfying results, equipment as well as technology should be continuously improved and updated. The most modern design tools should be adopted to maximize the coke production rate also ensuring the best coke quality. In this scenario, Paul Wurth is realizing the new coke making plant of CSPecem, Ceara - Brazil. These batteries are based on Paul Wurth “jumbo oven concept”. This solution incorporates all most modern features and design upgrading, in the aim of an easy and long-lasting operation putting a particular attention to environmental performances: the reduced number of ovens and the low number of pushing per day have the main effect of reducing pollution sources. Finally the paper will highlight Paul Wurth SOPRECO® System, which is foreseen to be installed in CSPecem batteries. SOPRECO®, which is capable of controlling the pressure for each individual oven in a coke oven battery, is thus able to reduce volatile emissions through doors, roofs and stand pipes up to 90%. The coke oven gas (COG) produced during the carbonization process is cleaned in a coke oven gas treatment plant to the level stipulated by applying the Best Available Technology (BAT).

Aug 1, 2018

By Rudolf Hubmer

In October 2013 JSW Steel decided to place an order to Primetals Technologies Austria (former Siemens VAI Metals Technologies) for the installation of a comprehensive Level 2 process optimization system for more than 20 existing production facilities of various suppliers. For SMS-I new L2 systems are provided for two hot metal pretreatment stations, three hot metal desulphurization stations, three ladle furnaces, two 1-strand slab casters, a ladle tracking system as well as a shop supervisory system. Additionally the existing L2 system for one 1-strand slab caster is being upgraded in the course of the project. In SMS-II new L2 systems for the 7 hot metal desulphurization stations, 4 ladle furnaces, 1 new RH vacuum degasser, ladle tracking system and a shop supervisory system are supplied. Despite of the challenging time schedule the commissioning of the single facilities started within less than 12 month after contract effectiveness. The installed Level 2 process optimization systems together with the achieved results are described in this paper.

Aug 16, 2017

By Juergen Meisel

The paper will explain how to successfully implement a robotic solution from the initial idea to a working industrial solution. Primetals Technologies can call upon 10 years of experience in installation of Robot solutions in the harsh environment of steelmaking plants - the so-called LiquiRob. To enhance an existing shroud manipulation system, the idea to connect the shroud with a bayonet mechanism to the ladle nozzle was born in accordance with the requirements of a well-known steel producer. The paper will describe the development steps from the first simulations and prototype testing in the laboratory, it will show the intensive system testing under workshop conditions and will finally depict the successful integration into the plant. Furthermore, operational experience will be shown as well as the advantages of such an installation compared to other shroud manipulation systems.

Oct 30, 2017

By Gilberto Álvares da Silva

New elements have been inserted in NiTi lately, resulting in ternary alloys with specific characteristics beyond Shape Memory Effect and Superelasticity. Among all others alloying elements, the Ag additions itself gives potential antibacterial activity to that smart material. So on, the elaboration procedures of ternary NiTiAg alloys was studied in order to obtain a melting procedure to ensure further studies on this alloy. Microstructural and thermal analyses were used to evaluate the VAR-remelting production of NiTiAg with 4.0% wt silver content. The microstructure is composed by a NiTi matrix, pure Ag precipitates, and, scarcely, TiC inclusions. Heat treatments at high temperature could not dilute those Ag particles, but could lead to the precipitation of new ones. The silver element reduces the temperature of the martensitic transformation, yielding a material with superelastic behavior, beyond induces the R-phase on cooling stage of this alloy.

Aug 8, 2018

By Wen Xuan

Oolitic iron ores have significant economical importance because of their extensive resources in the world. However, their utilisation is often quite limited due to the high content of phosphorus inside. The phosphorus is often finely disseminated in the oolite structure and generally not liberated in the form of free particles. The iron ore used in this work is a typical oolitic goethitic iron ore with high phosphorus. The process of phosphorus removal from this ore is difficult because the phosphorus is not present as distinct minerals. As a result, no physical beneficiation process is able to separate the phosphorus from the iron bearing phases. The current concentrate contains low iron grade (Fe ~49%) and high phosphorus content (P 0.7~0.8%). The acid leaching is a potential way to dissolve phosphorus. Previous studies have shown that the thermal treatment makes the phosphorus more accessible for the acids and enables more efficient phosphorus dissolution. Some chemical additives are reported to enhance this phenomenon. A series of tests have been carried out using roasting - grinding - magnetic separation - leaching technologies to remove the phosphorus from this current concentrate. In the first stage, several tests were performed at pilot scale under the same conditions as described in some publications. The achieved results were similar to those from previous tests at laboratory scale. In the second stage, new test conditions were investigated in laboratory scale in order to achieve better result and to reduce the operational cost.

Aug 1, 2018

By Uwe König

Traditionally quality control of iron ore sinter, its raw materials and raw mixtures has relied on time-consuming wet chemistry. The mineralogical composition that defines the properties is often not monitored. XRD analysis in combination with Rietveld quantification and statistical data evaluation using Partial Least-Square Regression (PLSR) has been successfully established to determine the mineralogical composition and process parameters such as the FeO (Fe2+) content and basicity of iron sinter within an analysis time of less than 8 minutes per sample. Both methods take the full XRD pattern into account and can be simultaneously applied on the same measurement. In addition the Rietveld method was used to quantify the phase content of raw mixtures to monitor the composition of blending beds.

Aug 16, 2017

By Simon Chiartano

A global reflection on the design of blast furnace main runner was investigated in this paper. TRB Company used its skills and expertise to understand what the best option for this sensitive component is, including some innovative tools: intelligent block design for safety lining, thermal & thermomechanical numerical simulation, immersive measurement by thermocouples, IR thermal camera, 3D laser scanner.

Oct 1, 2019

By Raúl Daniel López

Ternium-Siderar steelmaking has been focused in permanent improvements and process optimization. At present the Slab Continuous Caster N°1 has been totally transformed after 20 years of uninterrupted work. The authors of this paper summarize and comment on aspects which were the main changes and place emphasis largely on those technological developments in which they have been active during that period. Productivity and quality have been our goals during the last 20 years; it has led us to improve process and to achieve better control tools. In the development of this presentation, the authors will put special emphasis on the explanation of those works that were made following their own experiences through the technical personnel who belong to the staff of the company.

Jul 30, 2018

By Paul Pugsley

The need for dimensional measurement of products has always been there, now with the industry 4 push to further understand measure and to record process parameters is more important than ever. This applies to both flat and long products, camera systems have always provided the method to measure, stereo Linescan cameras for flat products and innovative applications using 2D and Linescan cameras for long products. Instrumentation will become more important to producers enabling processes to be better controlled and understood, that aim being to make the production process understandable more repeatable and less reliant on operator influence. Primetals Technologies Ltd offer solutions for all types of products.

Oct 30, 2017