Thomas Prietl et al.: The Evaluation of Refractory Linings Thermo-Mechanical Properties
The Evaluation of Refractory Linings
Thermo-Mechanical Properties
Thomas Prietl, Oliver Zach, Hans Studnicka
The increasing requirements for high performance furnaces in the metal industries has resulted in an increased
use of partially water cooled furnaces that require complex
furnace linings. However, with an increasing furnace lining
complexity, the refractory material expansion becomes a
determining factor. The expansion defaults must be calculated to achieve a minimal expansion of the surrounding
furnace steel shell, whilst in parallel ensuring a leak-proof
furnace bottom lining. Foremost, the cooling sections in the
side wall or bottom furnace area must be protected against
deformation due to excessive refractory expansion. The
problems that can arise due to cooling section damage are
well established and mainly occur in cooling sections that
have their cooling circuit inside the furnace (e.g., refractory
deformation can result in cooling water leaking into the
furnace). To enable future optimal furnace lining designs
which satisfy the technical requirements, a test plant was
established at the RHI Refractories Technology Center
Leoben, Austria. This work was performed in collaboration with the Christian Doppler Laboratory for Secondary
Metallurgy of Non Ferrous-Metals, University of Leoben,
Austria. The test plant has been operational since November 2004 and should provide important information for
lining concept designs.
Keywords:
Refractory – Thermal expansion – Furnace lining – BHTP
Ermittlung thermomechanischer Eigenschaften von feuerfesten Zustellungen
Die steigende Nachfrage der metallerzeugenden Industrie
nach längeren Ofenreisen resultierte in einem verstärkten
Einsatz von Kühlelementen, verbunden mit einer komplexeren Ofenzustellung. Mit der steigenden Komplexität
der Ofenzustellungen rückt das thermische Dehnungsverhalten des feuerfesten Materials in den Mittelpunkt. Die
Dehnungsvorgaben müssen richtig berechnet werden, um
eine kompakte geschlossene Zustellung ohne übermäßige
Deformation des Ofenmantels zu gewährleisten. Vor allem
müssen die in den Seitenwänden oder im Boden eines
Ofens eingebauten Kühlelemente gegen Beschädigung
durch eine übermäßige thermische Dehnung des feuerfesten Materials geschützt werden. Probleme, die bei einer Schädigung der Kühlelemente auftreten können, sind
hinreichend bekannt (Wassereinbruch in den Ofen). Um
zukünftige Ofenzustellung hinsichtlich der Erfordernisse
optimal auslegen zu können, wurde im RHI Technologiezentrum Leoben in Zusammenarbeit mit dem Christian Doppler Laboratorium für Sekundärmetallurgie der
Nichteisenmetalle ein Versuchsstand errichtet. Die Versuchsapparatur befindet sich seit November 2004 im Einsatz und soll wichtige Informationen für die Entwicklung
von Zustellungskonzepten liefern.
Schlüsselwörter:
Feuerfest – Thermische Dehnung – Ofenzustellung –
BHTP
La détermination des qualités thermo-mécaniques de revêlements réfractaires
Evaluación de las propiedades termomecánicas de revestimientos refractarios
Paper presented on the occasion of the European Metallurgical Conference EMC 2005, September 18 to 21, 2005 in
Dresden.
1
Introduction
During refractory lining design it has been shown that the
load carrying capacity of effective in service constructions
does not equate with the results of conventional computing methods. Typically, the static calculations predict larger
demands than actually occur in practice.
This is principally due to the complex behaviour of the
different materials used in the total furnace construction.
Therefore, refractory lining design still remains a civil engiWorld of Metallurgy – ERZMETALL 59 (2006) No. 3
neering concern and extensive static proofs are rarely provided. The construction of a furnace lining concept cannot
be performed without in service experiences and because
the material behavioural characteristics are very difficult
to calculate, the theoretical and in service results must be
analysed in parallel. Furthermore, to perform static refractory design analysis the following issues must be taken into
consideration:
• The walls consist of several layers and each layer must
fulfil different requirements including refractoriness,
127
Michael Köffel et al.: Refractories for the Copper and Lead Industry
Refractories for the Copper and Lead Industry
Michael Köffel, Thomas Taschler
Before selecting proper refractory materials, the metal
production process parameters have to be considered in
depth. One of the main wear parameters in furnaces of the
copper and lead industry is the corrosion by acid slags. In
the following article, mainly fayalithic slags, which are the
most common slags in the non ferrous metals industry will
be discussed. – But not only the chemistry of the refractory
material should fit to the process. In general, there are three
major impacts on refractories:
• the thermal influence which can result in a weakening
of the brick structure due to thermal shocks or infiltration;
• the mechanical influence due to erosion which leads to
abrasion and lining tensions as well as
• the chemical impact like slag corrosion, redox reactions
and SO2 diffusion.
These impacts are not only influenced by the chemical
composition of the refractories, it is also decisive for the
performance of the refractories which qualities of raw material are used as well as the preparation of the raw materials and the production quality. Affected by the grain size
and the bonding systems, the properties for each refractory
material can be varied regarding thermal, mechanical and
chemical properties and so the exposure of zones in the
furnace where the material should be installed should be
known very well. – In the following article, composition
of refractory materials and main wear mechanisms in furnaces of the copper and lead industry will be discussed.
Keywords:
Refractory – Copper – Lead – Non-ferrous metals – Pyrometallurgy
Feuerfeste Materialien für die Kupfer- und Bleiindustrie
Einer der Hauptverschleißmechanismen von feuerfesten
Materialien in der Kupfer- und Bleiindustrie ist der chemische Verschleiß durch saure Schlacken. Im nachstehenden Artikel werden hauptsächlich fayalithische Schlacken,
welche am verbreitetesten sind, diskutiert. Generell spricht
man von drei Hauptverschleißursachen:
schaftswerte betrachtet werden, sondern es muss auch
großes Augenmerk auf Qualität und Aufbereitung der
Rohmaterialien gelegt werden. Beeinflusst durch u.a.
Korngrößen und Bindesysteme können die Eigenschaften des Werkstoffs hinsichtlich thermischer, mechanischer
bzw. chemischer Beständigkeit variieren, woraus folgt,
dass die Beanspruchung der verschiedenen Zonen im
Ofen bekannt sein sollte. Im folgenden Artikel wird die
Zusammensetzung verschiedener Feuerfestmaterialien
sowie die Verschleißursachen in Öfen der Kupfer- und
Bleiindustrie beschrieben.
• thermischer Verschleiß, resultierend in einer geschwächten Gefügestruktur auf Grund von Thermoschocks und
Infiltrationen,
• mechanischer Verschleiß verursacht durch Erosion und
Mauerwerksspannungen sowie
• chemischer Verschleiß wie Schlackenkorrosion, Redoxreaktionen und SO2-Diffusion.
Schlüsselwörter:
Zur Auswahl des geeigneten Feuerfestmaterials dürfen
nicht nur die chemischen und physikalischen Eigen-
Feuerfest – Kupfer – Blei – Nichteisenmetalle – Pyrometallurgie
Materiaux réfractaires pour l’industrie du cuivre et du plomb
Materiales refractarios para las industrias de cobre y plomo
Paper presented on the occasion of the European Metallurgical Conference EMC 2005, September 18 to 21, 2005
in Dresden.
1
Typical slags in the copper and lead
industry
The main wear mechanism of refractory bricks in furnaces
of the copper and lead industry is corrosion by acid slags
and therefore it is necessary to know their composition to
make a suitable refractory choice. Slags are formed by a lot
of components, which are mainly oxides and can be classified according to their chemical behaviour:
World of Metallurgy – ERZMETALL 59 (2006) No. 3
basic oxides:
acid oxides:
amphoteric oxides:
salts:
e.g. CaO, MnO, FeO, MgO, Na2O
e.g. SiO2, P2O5
e.g. Al2O3, Fe2O3, TiO2
e.g. CaF2, CaS
The main slag type for the copper and lead industry is
formed by the system FeO–CaO–SiO2, or the so called
fayalitic slag type (Fe2SiO4). Those slags are showing significant high iron contents and are preferable based in the
133
Rolf Degel et al.: 100 years of SMS Demag Submerged Arc Furnace Technology
100 Years of SMS Demag Submerged Arc
Furnace Technology
Rolf Degel, Jens Kempken
After a short summary of the historical milestones of the
submerged arc furnace, the paper will highlight general
aspects of furnace design. Different applications and their
specific furnace requirements will be emphasized. Finally
a state of the art design tool as well as a new invention to
improve slag cleaning technology will be featured.
Keywords:
Submerged arc furnaces – Ferro alloys – FeCr – FeNi
– FeMn – Non-ferrous metals – Copper – Slag cleaning
– PGM – Rectangular furnace
100 Jahre SMS Demag Submerged Arc Furnace-Technologie
Nach einem kurzen historischen Rückblick über die Meilensteine des Elektroreduktionsofens werden Designaspekte hervorgehoben. Zahlreiche Anwendungsmöglichkeiten und damit verbundene Anforderungen an die
Technik werden beschrieben. Schließlich werden innovative Werkzeuge zur Prozessverbesserung sowie eine neue
Schlackereinigungsstufe vorgestellt.
Schlüsselwörter:
Elektroreduktionsofen – Ferrolegierung – FeCr – FeNi
– FeMn – Nichteisen-Metalle – Kupfer – Schlackereinigung
– Platin/Palladium – Rechtecköfen
100 ans de technologie du four à arc „Demag Submerged“
100 años de la tecnología del horno de arco sumergido en SMS Demag
Parts of the paper presented on the occasion of the European Metallurgical Conference EMC 2005, September 18 to
21, 2005, in Dresden.
1
History of the submerged arc furnace
100 years of submerged arc furnace technology (SAF), a
remarkable achievement by SMS Demag! We are proud
of looking back at our involvement in this technology in
which SMS Demag played a significant role in the development of this smelter.
During the last century, the submerged arc furnace has
been one of metallurgy’s most amazing diversified melting
units which has found many applications in over 20 different industrial areas, including ferro-alloys, iron, silicon
metal, copper, lead, zinc, refractory, titanium oxide, calcium
carbide, phosphorus and materials recycling, etc. [1].
SMS Demag has been developing this technology for more
than 100 years and has supplied a diverse market with about
700 furnaces and major furnace components [2]. Numerous
applications were constantly developed (Table 1) serving
various users [3].
Such an evolution was only possible because of tremendous efforts in research and development and due to the
large range of design solutions.
World of Metallurgy – ERZMETALL 59 (2006) No. 3
The increasing demand for ferroalloys and desoxidation
agents in steelmaking at the beginning of the 20th century
led to the development of the first few furnaces.
Demag, for the last two centuries a major supplier for the
iron and steel industry, started with the construction of
the first submerged arc furnace in 1906. The 1.5 MVA unit
was installed in Horst, Ruhr/Germany, for the production
of calcium carbide and was successfully commissioned
Tab. 1: Various applications of SMS Demag’s furnaces [3]
User industries
Alloys/products
Iron & steel industry
(main applications)
Ferro-nickel, ferro-chrome, ferrosilicon,
ferro-manganese, silico-manganese, ...
Iron & steel industry
(additional applications)
Ferro-tungsten, ferro-tantalum, ferro-niob,
Calcium-silicon, ferro-vanadium, ...
Non-ferrous metals
industry
Copper, lead, antimon/bismuth, zinc,
nickel/copper matte, platinum, ...
Refractory & grinding
industry
Corundum, mullite, fused magnesite, fused
oxides, mineral wool, ...
Chemical & electronic
industry
Calcium carbide, titanium slag, phosphorous, silicon metal, ...
143
Christian Hagelüken: Recycling of Electronic Scrap at Umicore’s Integrated Metals Smelter and Refinery
Recycling of Electronic Scrap at Umicore’s
Integrated Metals Smelter and Refinery
Christian Hagelüken
With the new legislation for Waste Electrical and Electronic
Equipment (WEEE) coming up in Europe and similar
developments in other parts of the world, a substantial
increase of end-of-life electronic equipment to be treated
will take place on a global scale. In this context, often
much attention is placed on logistical issues, dismantling
and shredding/pre-processing of electronic-scrap, while the
final, physical metals recovery step in a smelter is often just
taken for granted. However, a state-of-the-art smelter and
refinery process has a major impact on recycling efficiency,
in terms of elements and value that are recovered as well
as in terms of overall environmental performance. Besides
copper and precious metals, modern integrated smelters
recover a large variety of other elements, and can make use
of organics such as plastics to substitute coke as a reducing
agent and fuel as an energy source. Umicore has recently
completed major investments at its Hoboken Works, com-
pletely shifting the plants focus from mining concentrates
to recyclable materials and industrial by-products. Based
on complex Cu/Pb/Ni metallurgy, the plant has been developed to the globally most advanced full-scale processor
of various precious metals containing fractions from electronic scrap, generating optimum metal yields for precious
and special metals at increased productivity and minimised
environmental impact. Especially the interface between
pre-processing (shredding/sorting) and integrated smelting
offers additional optimisation potential, which can lead to
a substantial increase in overall (precious) metals yields.
Keywords:
Electronic scrap – Integrated metals smelting – Circuit
board & mobile phone recycling – Precious metals – Interface optimisation
Recycling von Elektronikschrott in Umicores integriertem Metallhütten-Prozess
Die Einführung der europäischen Elektroaltgeräteverordnung (WEEE-directive) und ähnlicher Gesetzesinitiativen
in anderen Regionen wird weltweit zu einem signifikantem
Anstieg an zu verwertendem Elektronikschrott führen. In
diesem Kontext wird häufig großes Augenmerk auf logistische Aspekte sowie auf Zerlegung und Vorbehandlung
(Shreddern & Aufbereitung) von E-Schrott gerichtet, während der eigentlichen, physischen Metallrückgewinnung
in Hütten oft weit weniger Beachtung geschenkt wird.
Tatsächlich aber hat ein moderner, für das E-Schrott-Recycling optimierter Hütten- und Raffinationsprozess einen
siknifikanten Einfluss auf die Effizienz der gesamten Recyclingkette, sowohl in Bezug auf rückgewinnbare Metalle
und Wertinhalt als auch hinsichtlich der Ökobilanz der
Verwertung. Dem Stand der Technik entsprechende integrierte Hütten können neben Kupfer und Edelmetallen
eine breite Palette anderer Metalle zurückgewinnen. Organische Stoffe (z.B. Kunststoffe) finden dabei Verwendung
als Substitut für Koks (Reduktionsmittel) und Schweröl
(Energie). Umicore hat im Werk Hoboken in den letzten
Jahren erhebliche Investitionen getätigt, durch welche die
ehemalige Primärhütte vollständig in eine Sekundärhütte
für Recyclingmaterial und Hüttenbeiprodukte umgewandelt wurde. Basierend auf einer komplexen Cu/Pb/Ni-Metallurgie wurde die Anlage zum weltweit modernsten Endverarbeiter von edelmetallhaltigen Fraktionen entwickelt,
mit dem optimierte Metallausbeuten bei erhöhter Produktivität und minimierter Umweltbeanspruchung erzielt
werden. Eine weitere Optimierung der Recyclingkette
kann vor allem an der Schnittstelle zwischen mechanischer
Aufbereitung und integrierter Verhüttung erreicht werden,
wodurch die Gesamtausbeute an (Edel-)Metallen deutlich
verbessert würde.
Schlüsselwörter:
Elektronikschrott – Integrierte Metallhütte – Recycling
von Leiterplatten und Mobiltelefonen – Edelmetalle –
Schnittstellenoptimierung
Recyclage de déchets électroniques à la fonderie/raffinerie intégrée de métaux d’Umicore
Reciclage de residuos electrónicos en la integrada funda/refinería de metales de Umicore
Paper presented on the occasion of the European Metallurgical Conference EMC 2005, September 18 to 21, 2005,
in Dresden.
152
World of Metallurgy – ERZMETALL 59 (2006) No. 3
Mahin Rameshni et al.: Production of Elemental Sulphur from SO2 (RSR)
Production of Elemental Sulphur from SO2 (RSR)
Mahin Rameshni, Stephen Santo
WorleyParsons innovative SO2 reduction process efficiently recovers sulphur from SO2 streams. Effluent gases from
ore roasters and smelters and coal-fired power plants can
be treated to reduce sulphur emissions. This exciting new
process is an innovative combination of well-established
processes of reaction of CH4 and sulphur vapor to produce
CS2, followed by catalytic hydrolysis of CS2 to H2S, and
Claus reaction of H2S and SO2 to sulphur. Key advan-
tages are lower fuel consumption, reduced emissions, better product sulphur quality and better operational stability. The production of elemental sulfur from SO2 is being
called Rameshni SO2 Reduction (RSR) and it is patent
pending.
Keywords:
SO2 reduction – off gas – Claus reaction – sulphur – RSR
Herstellung von elementarem Schwefel aus SO2 (RSR)
WorleyParsons innnovativer SO2-Reduktionsprozess dient
der wirtschaftlichen Gewinnung von Schwefel aus SO2haltigen Abgasströmen. Den Röstgasen von Metallhütten, die sulfidische Erze verarbeiten, sowie den Abgasen
von Kohlekraftwerken wird der darin enthaltene Schwefel entzogen. Dieser neue Prozess stellt eine innovative
Kombination des etablierten Verfahrens der Reaktion von
CH4 und Schwefeldampf zu CS2 und der darauf folgenden katalytischen Hydrolyse von CS2 zu H2S sowie der
Claus-Reaktion von H2S und SO2 zu Schwefel dar. Vorteile
des Prozesses sind niedrigerer Energieeinsatz, reduzierte
Emissionen, verbesserte Qualität des Produkts Schwefel
und große Betriebsstabilität. Die Gewinnung von elementarem Schwefel aus SO2 wurde als Rameshni-SO2-Reduktion (RSR) zum Patent angemeldet.
Schlüsselwörter:
SO2-Reduktion – Abgas – Claus-Reaktion – Schwefel
– RSR
Production de soufre élémentaire à partir de SO2 (RSR)
Producción de azufre elemental del SO2 (RSR)
1
Introduction
Environmental regulatory agencies of many countries continue to promulgate more stringent standards for sulphur
emissions from Industrial sources. Many plants around the
world, ore smelters, in particular, are still allowed to emit
large quantities of SO2 because of their remote locations
and the high cost of mitigation, but those exemptions are
running out as governments become more environmentally responsible. With the renewed interest in high sulphur
coal for power production and increased activity in the
mining and metals sectors, it is necessary to develop and
implement reliable and cost-effective technologies to cope
with the changing requirements.
Sulphur dioxide is found in a many industrial gases emanating from plants involved in roasting, smelting and sintering sulfide ores, or gases from power plants burning
high sulphur coal or fuel oils or other sulfurous ores or
other industrial operations involved in the combustion of
sulfur-bearing fuels, such as fuel oil. One of the more difficult environmental problems facing industry is how to
economically control SO2 emissions from these sources.
162
In general, smelter gases contain about 2 % to 16 % SO2 by
volume while gases from other sources may vary from 1 %
to 100 % SO2 with the other components usually comprising oxygen, nitrogen, carbon dioxide and water vapor.
Few commercially feasible processes for the reduction of
SO2 to elemental sulfur have been developed. The reduction
of SO2 to elemental sulfur has been investigated extensively
over a period of nearly 100 years, and the basic SO2 reduction process using a hydrocarbon reducing agent is discussed
in many articles and patents. Thermal and catalytic reduction processes have both been investigated over the years.
The general problems using hydrocarbon as a reducing
agent are listed below.
•
•
•
•
•
Low sulphur recovery efficiency
High fuel consumption
High cost
Difficult operation
Soot formation produces off-color sulphur and fouls
catalyst beds
• By products, such as hydrogen and CO, increase the gas
volume requiring larger plants
World of Metallurgy – ERZMETALL 59 (2006) No. 3
Reinhard Schwaiger et al.: Porous Plugs – A New Generation of Degassing Technology in Aluminium Foundry Ladles
Porous Plugs – A New Generation of Degassing
Technology in Aluminium Foundry Ladles
Report by Reinhard Schwaiger, Klaus Gamweger
The quality requirements for alloys increase continuously,
also in the field of the aluminum industry. In this case the
reduction of the hydrogen content is of decisive importance. The degassing can be carried out directly in the holding furnace, or in the foundry transport ladles, with the help
of a stationary degassing device. In the AL KIN System
introduced here, porous plugs are installed in the bottom
of these ladles. With these, the hydrogen content can be reduced in the metal bath quickly and very efficiently. Mostly,
the step of degassing is the bottleneck in the production,
so that the time saved directly affects the productivity of
the facility. A further advantage of this system is that no
moving parts are used, contrary to the system with rotating
lances. These have to be changed frequently and represent
high costs and maintenance work. This article shows the
operation of this system and the results achieved by the
example of a 1.2 t foundry transport ladle.
Keywords:
Aluminum – Porous plugs – Ladle – Degassing – Hydrogen
Poröse Spülsteine – Eine neue Generation der Entgasungstechnologie für Gießereipfannen in der Aluminiumindustrie
Die Qualitätsanforderungen bei Legierungen steigen auch
im Bereich der Aluminiumindustrie ständig an. Dabei ist
die Reduzierung des Wasserstoffgehaltes von entscheidender Bedeutung. Die Entgasung kann direkt im Halteofen
durchgeführt werden, oder in den Überführungspfannen
mit Hilfe von Entgasungsstationen. In dem hier vorgestellten AL KIN-System werden poröse Spülsteine im Boden
dieser Pfannen installiert. Mit diesen kann der Wasserstoffgehalt im Metallbad schnell und effizient reduziert werden.
Meist stellt der Entgasungsschritt den Bottleneck in der
Produktionskette dar, so dass die eingesparte Zeit sich
direkt auf die Produktivität der Anlage auswirkt. Dass hier
keine beweglichen Teile eingesetzt werden, ist ein weiterer
Vorteil dieses Systems gegenüber dem der rotierenden
Lanzen. Diese verschleißen schnell und stellen einen hohen Kosten- und Arbeitsaufwand für die Instandhaltung
dar. Dieser Artikel zeigt die Arbeitsweise dieses Systems
und die erzielten Ergebnisse anhand einer 1,2-TonnenPfanne.
Schlüsselwörter:
Aluminium – Spülsteine – Pfanne – Entgasen – Wasserstoff
Bouchons poreux – une technologie de dégazage de la nouvelle génération dans les poches de transfer
Tapones porosos – una nueva generación de tecnología de desgasificación para cucharas usados en la industria del
aluminio
1
Introduction
The treatment of molten metals with purging gases is a
well established practice in non-ferrous metallurgy. In the
aluminium industry, inert or reaction gases are blown into
the melt using porous plugs at multiple steps in the process, including in melting and holding furnaces, and more
recently in ladles. To enable effective gas purging during
aluminium production RHI Refractories developed the
AL KIN system, a complete package that includes porous
plugs, refractory expertise, gas supply technology, and gas
control equipment.
The main role of gas purging in aluminium melting furnaces is to increase the melting rate and homogenization of
the alloying elements. By contrast, in holding furnaces the
principal focus is the removal of inclusions and a decrease
World of Metallurgy – ERZMETALL 59 (2006) No. 3
in the hydrogen content, in addition to temperature and
chemical homogenization of the melt. Subsequently, when
the high quality aluminium is transferred from the holding
furnace to the caster or dosing furnace using transport ladles, an additional degassing step is necessary to reduce the
hydrogen content to the required minimum. Whilst rotary
lances can be employed at this stage, the ladle must be fully
charged and moved to the degassing station prior to the
purging step. In contrast, the transport distance and degassing time can be significantly reduced using porous plugs
installed in ladles because the plugs are an integral part of
the ladle and purging can begin as the ladle is charged. At
RHI Refractories, the AP4 porous plug has been optimized
for ladle purging requirements, and by providing a rapid
degassing method aluminium cooling during the transport
step is decreased.
169