WO1982003339A1 - Ceramic filter,method for manufacturing and utilizing this filter - Google Patents
Ceramic filter,method for manufacturing and utilizing this filter Download PDFInfo
- Publication number
- WO1982003339A1 WO1982003339A1 PCT/CH1982/000048 CH8200048W WO8203339A1 WO 1982003339 A1 WO1982003339 A1 WO 1982003339A1 CH 8200048 W CH8200048 W CH 8200048W WO 8203339 A1 WO8203339 A1 WO 8203339A1
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- WIPO (PCT)
- Prior art keywords
- ceramic filter
- filter
- ceramic
- gekenn
- foam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/06—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
- C04B38/0615—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances the burned-out substance being a monolitic element having approximately the same dimensions as the final article, e.g. a porous polyurethane sheet or a prepreg obtained by bonding together resin particles
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires
- B01D39/2068—Other inorganic materials, e.g. ceramics
- B01D39/2093—Ceramic foam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22C9/084—Breaker cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22C9/086—Filters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22C9/088—Feeder heads
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
- B22D1/007—Treatment of the fused masses in the supply runners
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B21/00—Obtaining aluminium
- C22B21/06—Obtaining aluminium refining
- C22B21/066—Treatment of circulating aluminium, e.g. by filtration
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/02—Refining by liquating, filtering, centrifuging, distilling, or supersonic wave action including acoustic waves
- C22B9/023—By filtering
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the invention relates to a ceramic filter with an open-cell foam structure based on Al-O or other highly refractory, in particular high-alumina materials for filtering metal melts, a process for its production and its use for cleaning molten metals and metal alloys, preferably iron .
- DE-OS 2 848 005 describes a porous ceramic filter with a relatively low permeability for filtering
- OMPI Aluminum melting known.
- the main object of the present invention is to provide a ceramic filter which also enables effective cleaning of such metal melts which have a high degree of resistance to temperatures above 1000 ° C., in particular of cast iron.
- the task is to create a ceramic filter of the aforementioned type, which has a high temperature resistance in the range of 1350 - 1650 C and allows a high potting speed.
- Another object of the present invention is to provide a method for the production of such a ceramic filter, which both guarantees compliance with the required specifications and also permits rational production for mass production.
- the invention thus relates to a ceramic filter with an open-cell foam structure based on Al 2 O_ or other highly refractory substances for filtering metal melts, characterized by a flow rate of 200 to 5000 cm 3 of melt per cm 2 of filter area per minute.
- the flow rate according to the invention can be achieved by a large number of combinations of the main parameters, number of pores per cm / porosity / thickness of the filter, and applies to a position of the pouring funnel above the filter of 15 to 30 cm.
- the filters according to the invention in particular when casting cast iron, have a significantly improved cleaning effect compared to the previously known agents and, because of their temperature resistance, also have increased operational reliability.
- the use of the filter according to the invention does not change the composition of the filtered melt.
- a ceramic filter which is preferably 0.5 to 18 per centimeter in length 0.5 - 8, has pores.
- the desired coarse toxicity results in a lower porosity compared to known filters, which extends from 0.95 down to 0.3.
- the porosity P is determined using the following formula:
- the open-cell foam structure should have a high degree of uniformity. It should be noted here that at most 5%, preferably at most 2%, blocked pores, if possible in a uniform distribution, are present in order to avoid channel formation and thus a reduction in the efficiency of the filter.
- a large number of materials can be used to manufacture the filter according to the invention.
- the main constituent is preferably Al 2 O 3 in an amount of 60-95% by weight, preferably 75-80% by weight.
- highly refractory materials in particular those containing high alumina, can also be used, e.g. Sillimannite, mullite or chamotte.
- aluminosilicates for example kaolin
- aluminosilicates for example kaolin
- Another component is the glow product of a binder, e.g. Monoaluminum phosphate, which by the setting process according to the formula:
- An open-cell foam structure of an organic material is impregnated with a slurry of a composition containing ceramic aluminum oxide and a binder. The slurry solvent and organic substance are then removed. - 6 -
- the organic material can be a reticulated.
- the slurry is preferably an aqueous e.g. with a share of 3 - 8% water.
- the composition advantageously has a viscosity in the range of 10 4 to 2-104 centipoise at 20 revolutions per minute.
- the excess slurry is removed from the foam by passing the impregnated foam through a system of pairs of rollers. The foam is then dried to remove the water.
- the organic substance and the residual water can be removed by heating, for example to above 225 ° C.
- Particularly effective filters can be produced by subjecting them to a re-impregnation in order to secure the exposed cell webs lying on the surface of the filter against breaking and to give the filter an increased temperature resistance.
- the dried and impregnated foam described above is subjected to a further impregnation with a ceramic slurry on the surface, dried again and heated to remove the organic substance and at temperatures between 1200 ° C and 1500 ° C, preferably between 1350 C and 1450 ° C calcined.
- the impregnated ceramic filter is dried at temperatures between 150 ° C. and 600 ° C., preferably between 250 ° C. and 350 ° C.
- a wetting agent in an amount of, for example, 0.5-2.0% by weight has proven to be advantageous.
- the thixotropic ceramic material can be produced according to the above in a variety of formulations, but particularly good results are obtained with 65% A1 2 0 3 , 3% kaolin, 1% alkylbenzenesulfonate as wetting agent, 25% monoaluminum phosphate and 6 % Water achieved.
- the filter earths are used in front of or in the sand mold or the mold, with installation to be as close as possible to the casting.
- 1 to 6 show partial sections of the cavities of a mold in a perspective view.
- Fig. 1 shows the arrangement of a ceramic filter 1 in the barrel 2 of a mold, such as a sand mold, where
- the barrel is arranged between a sprue 3 having a sprue and the mold cavity (not shown).
- the first part 2a of the barrel branching off from the sprue 3 is arranged in the lower mold part, the ceramic filter 1 being arranged at the other widened end thereof.
- the second part 2b of the barrel is then arranged in the upper part of the mold and leads from the shown extended end, which is arranged above the ceramic filter 1, to the mold cavity.
- the melt poured into the sprue 3 thus flows through the ceramic filter from bottom to top, the filtered melt passing through part 2b of the barrel into the mold cavity.
- FIG 3 shows the arrangement of a ceramic filter 1 designed as a round plate between the sprue 3 and the barrel 2 leading to the mold cavity, the filter 1 likewise being easily insertable into the mold base provided with the barrel 2 and from above is flowed through by the melt below.
- FIG. 4 shows the arrangement of the ceramic filter 1 between the barrel 2 and a closed feeder 4 - also called ingot - arranged above it in the upper part of the mold, from which the melt directly into the cavity of the mold to be produced Casting 5 arrives.
- the ceramic filter 1 is flowed through by the melt from bottom to top and can be inserted into the bottom part of the mold from above.
- the ceramic filter 1 is arranged between the closed feeder 4 and the mold cavity for the casting 5.
- the plate-shaped ceramic filter 1 is used in a vertical position in the bottom mold part and / or upper mold and also serves as a pre-recorded breaking point - also called refractive core - 'for the separation of the casting 5 from the group consisting of sprue 3, Run 2 and Suiter 4 gating system.
- FIG. 6 shows the direct use of a ceramic filter 1 between the inlet spigot 3 and the casting 5, the ceramic filter 1 also forming the predetermined breaking point here.
- the ceramic filter is flowed through by the melt from top to bottom, whereby an arrangement on the lower part of the casting 5 with a flow from bottom to top is also possible.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Manufacturing & Machinery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Structural Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Filtering Materials (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
Abstract
Un filtre en ceramique de structure poreuse a alveoles ouvertes, a base d'oxyde d'aluminium ou d'autres substances hautement refractaires, en particulier a teneur elevee en alumine, est utilise pour filtrer, respectivement pour purifier des metaux en fusion dont la temperature de coulee est superieure a 1000 C, notamment de la fonte en fusion, lors de la coulee dans des moules en sable ou dans des coquilles. La vitesse de passage a travers le filtre s'eleve a 200 - 5000 cm3 de matiere en fusion par cm2 de surface du filtre par minute. La fabrication du filtre en ceramique utilisable a la maniere d'un article a jeter est realisee a l'aide d'un liant au phosphate de monoaluminium.A ceramic filter of porous structure with open cells, based on aluminum oxide or other highly refractory substances, in particular with a high alumina content, is used to filter, respectively to purify molten metals whose temperature of casting is higher than 1000 C, in particular of molten cast iron, during casting in molds in sand or in shells. The speed of passage through the filter is 200 - 5000 cm3 of molten material per cm2 of filter surface per minute. The manufacture of the ceramic filter usable as a disposable article is carried out using a monoaluminum phosphate binder.
Description
Keramikfilter, Verfahren zu dessen Herstellung und seine Verwendung Ceramic filter, process for its production and its use
Die Erfindung betrifft einen Keramikfilter mit offen- zelliger Schaumstruktur auf der Basis von Al-O oder sonstigen hochfeuerfesten, insbesondere hochtonerdehaltigen Stoffen zum Filtrieren von Metallschmelzen, ein Verfahren zu dessen Herstellung und seine Verwendung zur Reinigung von geschmolzenen Metallen und Metalllegierungen, vorzugs¬ weise von Eisen.The invention relates to a ceramic filter with an open-cell foam structure based on Al-O or other highly refractory, in particular high-alumina materials for filtering metal melts, a process for its production and its use for cleaning molten metals and metal alloys, preferably iron .
Beim Vergiessen von Metallen, welche Schmelztemperaturen über 1000 C erfordern, wie z.B. Gusseisen, Stahlguss bzw. Stahlgusslegierungen ist es bekannt, für die Filterung Siebkerne aus gebrannten Schamotten oder Kernsand zu ver¬ wenden. Nachteilig ist hierbei die unzureichende Filter¬ wirkung aufgrund der relativ grossen Löcher der Siebkerne. Auch hochfeuerfeste Glasfasersiebe haben sich in der Praxis nicht bewährt.When casting metals that require melting temperatures above 1000 C, e.g. Cast iron, cast steel or cast steel alloys, it is known to use sieve cores from fired chamottes or core sand for filtering. The disadvantage here is the insufficient filter action due to the relatively large holes in the screen cores. Even highly refractory glass fiber screens have not proven themselves in practice.
Aus der DE-OS 2 848 005 ist ein poröser Keramikfilter relativ geringer Durchlässigkeit zum Filtrieren vonDE-OS 2 848 005 describes a porous ceramic filter with a relatively low permeability for filtering
OMPI Aluminiumschmelzen bekannt. Die geringe Durchlässigkeit von 12,7 - 127 cm 3 flüssigen Metalls pro cm2 Filterober¬ fläche und Minute (bei einer Höhe des Eingusstrichters über dem Filter von 15 bis 30 cm) und die beschränkte Temperaturbeständigkeit des für Aluminiumschmelzen mit einer Vergiesstemperatur von ca. 750 C ausgelegten vorbe¬ kannten Keramikfilters macht diesen allerdings ungeeignet für den Einsatz beim Vergiessen von Metallen mit einer deutlich höheren Vergiesstemperatur, wie beispielsweise Eisen und dessen Legierungen.OMPI Aluminum melting known. The low permeability of 12.7 - 127 cm 3 of liquid metal per cm 2 of filter surface and minute (at a height of the pouring funnel above the filter of 15 to 30 cm) and the limited temperature resistance of aluminum melts with a casting temperature of approx. 750 C designed known ceramic filters make them unsuitable for use when casting metals with a significantly higher casting temperature, such as iron and its alloys.
Hauptaufgabe der vorliegenden Erfindung ist es einen Keramikfilter zu schaffen, der eine wirkungsvolle Reini¬ gung auch von solchen Metallschmelzen ermöglicht, die eeiinnee VVeerrggiieesssstteemmppeerraattuurr *von über 1000 C aufweisen, ins- besondere von Gusseisen.The main object of the present invention is to provide a ceramic filter which also enables effective cleaning of such metal melts which have a high degree of resistance to temperatures above 1000 ° C., in particular of cast iron.
Im speziellen liegt die Aufgabe in der Schaffung eines Keramikfilters der vorgenannten Art, welcher eine hohe Temperaturbeständigkeit im Bereich von 1350 - 1650 C aufweist und eine hohe Vergiessgeschwindigkeit erlaubt.In particular, the task is to create a ceramic filter of the aforementioned type, which has a high temperature resistance in the range of 1350 - 1650 C and allows a high potting speed.
Eine weitere Aufgabe bei vorliegender Erfindung besteht in der ZurverfügungsStellung eines Verfahrens zur Her¬ stellung eines solchen Keramikfilters, das sowohl die Einhaltung der erforderlichen Spezifikationen garantiert als auch eine rationelle Fertigung für die Massenproduk¬ tion erlaubt.Another object of the present invention is to provide a method for the production of such a ceramic filter, which both guarantees compliance with the required specifications and also permits rational production for mass production.
"Weitere Aufgaben und Vorteile sind aus der nachstehenden Beschreibung ersichtlich. Erfindungsgemäss werden die Aufgaben nach einem Produkt gemäss Anspruch 1, vorzugsweise gemäss Anspruch 2 und nach einem Verfahren gemäss Anspruch 12 gelöst."Other tasks and advantages are apparent from the description below. According to the invention, the objects are achieved according to a product according to claim 1, preferably according to claim 2 and according to a method according to claim 12.
Gegenstand der Erfindung ist somit ein Keramikfilter mit offenzelliger Schaumstruktur auf der Basis von Al20_ oder sonstigen hochfeuerfesten Stoffen zum Filtrieren von Me¬ tallschmelzen, gekennzeichnet durch eine Durchflussge¬ sscchhwwiinnddiiggkkeeiitt vvoonn .200 - 5000 cm 3 Schmelze pro cm2 Filter- fläche pro Minute.The invention thus relates to a ceramic filter with an open-cell foam structure based on Al 2 O_ or other highly refractory substances for filtering metal melts, characterized by a flow rate of 200 to 5000 cm 3 of melt per cm 2 of filter area per minute.
Die erfindungsgemässe Durchflussgeschwindigkeit lässt sich durch eine Vielzahl von Kombinationen der Hauptparameter Porenanzahl pro cm / Porosität / Dicke des Filters er¬ reichen und gilt für eine Lage des Eingusstrichters über dem Filter von 15 bis 30 cm.The flow rate according to the invention can be achieved by a large number of combinations of the main parameters, number of pores per cm / porosity / thickness of the filter, and applies to a position of the pouring funnel above the filter of 15 to 30 cm.
Es ist gefunden worden, dass die erfindungsgemässen Filter, insbesondere beim Vergiessen von Gusseisen, gegenüber den bisher bekannten Mitteln eine deutlich verbesserte Reini¬ gungswirkung und wegen ihrer Temperaturbeständigkeit auch eine erhöhte Betriebssicherheit aufweisen. Zudem bewirkt die Verwendung des erfindungsgemässen Filters keine Ver¬ änderung der Zusammensetzung der filtrierten Schmelze.It has been found that the filters according to the invention, in particular when casting cast iron, have a significantly improved cleaning effect compared to the previously known agents and, because of their temperature resistance, also have increased operational reliability. In addition, the use of the filter according to the invention does not change the composition of the filtered melt.
Zahlreiche Vorteile werden bei der Verwendung des erfin¬ dungsgemässen Filters erreicht, von denen eine Anzahl vorstehend erwähnt sind und nachstehend ausführlicher besprochen werden.Numerous advantages are achieved when using the filter according to the invention, a number of which are mentioned above and are discussed in more detail below.
Vorteilhafterweise wird ein Keramikfilter verwendet, welcher pro Zentimeter Längenausdehnung 0,5 - 18, vorzugsweise 0,5 - 8, Poren aufweist. Die relative Grobporigkeit des erfindungsgemässen Filters zusammen mit einer möglichst geringen Dicke des Filters z.B. 1 cm bewirken eine hohe Durchflussgeschwindigkeit, was eine Schonung des Form¬ stoffes bedeutet.Advantageously, a ceramic filter is used, which is preferably 0.5 to 18 per centimeter in length 0.5 - 8, has pores. The relative coarse pores of the filter according to the invention together with the smallest possible thickness of the filter, for example 1 cm, result in a high flow rate, which means protecting the molding material.
Durch die gewünschte Grobpoxigkeit ergibt sich gegenüber bekannten Filtern eine geringere Porosität, die sich von 0,95 bis hinunter zu 0,3 erstreckt. Die Porosität P wird dabei nach folgender Formel bestimmt:The desired coarse toxicity results in a lower porosity compared to known filters, which extends from 0.95 down to 0.3. The porosity P is determined using the following formula:
*κ " ds* κ "d s
K in der d_ die Dichte der festen keramischen Masse und d_ die Dichte des keramischen Schaumes ist.K in which d_ is the density of the solid ceramic mass and d_ the density of the ceramic foam.
um ein wirksames Filter zu erhalten sollte die offen- zellige Schaumstruktur einen hohen Gleichförmigkeitsgrad aufweisen. Dabei ist zu beachten, dass höchstens 5 %, vorzugsweise höchstens 2 % blockierte Poren, möglichst in gleichmässiger Verteilung, vorhanden sind um eine Kanal¬ bildung und damit eine Herabsetzung des Wirkungsgrades des Filters zu vermeiden.In order to obtain an effective filter, the open-cell foam structure should have a high degree of uniformity. It should be noted here that at most 5%, preferably at most 2%, blocked pores, if possible in a uniform distribution, are present in order to avoid channel formation and thus a reduction in the efficiency of the filter.
Eine grosse Anzahl von Materialien kann zur Herstellung des erfindungsgemässen Filters verwendet werden.A large number of materials can be used to manufacture the filter according to the invention.
Hauptbestandteil ist dabei vorzugsweise Al2O3 in einer Menge von 60 - 95 Gew. %, vorzugsweise von 75 - 80 Gew. %.The main constituent is preferably Al 2 O 3 in an amount of 60-95% by weight, preferably 75-80% by weight.
Es können aber auch andere hochfeuerfeste, insbesondere hochtonerdehaltige Stoffe verwendet werden, wie z.B. Silli- mannit, Mullit oder Schamotte.However, other highly refractory materials, in particular those containing high alumina, can also be used, e.g. Sillimannite, mullite or chamotte.
'BUREΛ Als besonders vorteilhaft hat sich die Verwendung von Aluminiumoxidpulver erwiesen bei dem mindestens 90 % der Partikel eine maximale Ausdehnung von 4*10 m, vor¬ zugsweise l-lθ" m und eine plättchenförmige Struktur aufweisen.'BUREΛ The use of aluminum oxide powder has proven to be particularly advantageous in which at least 90% of the particles have a maximum extent of 4 * 10 m, preferably l-l0 " m and a plate-like structure.
Weitere Bestandteile des erfindungsgemässen Filters sind Glühprodukte von Alumosilikaten, beispielsweise Kaolin, in einer Menge von 2 - 10 Gew. %, vorzugsweise von 3 - 5 Gew. %.Further constituents of the filter according to the invention are annealed products of aluminosilicates, for example kaolin, in an amount of 2 to 10% by weight, preferably 3 to 5% by weight.
Ein weiterer Bestandteil ist das Glühprodukt eines Binders, z.B. Monoaluminiumphosphat, der durch den Abbindeprozess nach der Formel:Another component is the glow product of a binder, e.g. Monoaluminum phosphate, which by the setting process according to the formula:
Al203 + A1(H2P04)3 ^3A1P04 + 3H20Al 2 0 3 + A1 (H 2 P0 4 ) 3 ^ 3A1P0 4 + 3H 2 0
zu Alu iniumorthophosphat umgewandelt wird.is converted to aluminum orthophosphate.
Die Verwendung von Cr20-, wie sie bei bekannten Filtern zur Hochtemperaturbeständigkeit notwendig ist, erübrigt sich beim erfindungsgemässen Filter.The use of Cr 2 0-, as is necessary in known filters for high temperature resistance, is not necessary in the filter according to the invention.
Nach vorliegender Erfindung werden die vorstehenden Auf¬ gaben und die Vorteile in einfacher Weise nach dem folgen¬ den Herstellungsverfahren erhalten.According to the present invention, the above tasks and the advantages are obtained in a simple manner by the following manufacturing process.
Eine offenzellige Schaumstruktur eines organischen Mate¬ rials wird mit einer Aufschlämmung einer keramischen Aluminiumoxid enthaltenden Zusammensetzung und einem Binder imprägniert. Anschliessend wird das Lösungsmittel der Aufschlämmung und die organische Substanz entfernt. - 6 -An open-cell foam structure of an organic material is impregnated with a slurry of a composition containing ceramic aluminum oxide and a binder. The slurry solvent and organic substance are then removed. - 6 -
Das organische Material kann ein retikulierter. Polyurethan¬ schaum auf Polyester- oder Polyätherbasis mit einem εkelettartigen Netz von Zellstegen dreidimensionaler Struktur sein.The organic material can be a reticulated. Polyurethane foam based on polyester or polyether with a skeleton-like network of cell webs of three-dimensional structure.
Die Aufschlämmung ist vorzugsweise eine wässerige z.B. mit einem Anteil von 3 - 8 % Wasser.The slurry is preferably an aqueous e.g. with a share of 3 - 8% water.
Die wässerige Aufschlämmung der hochthixotropen keramischenThe aqueous slurry of the highly thixotropic ceramic
Zusammensetzung weist vorteilhafterweise eine Viskosität im Bereich von 10 4 bis 2-104 Zentipoise bei 20 Umdrehungen pro Minute auf.The composition advantageously has a viscosity in the range of 10 4 to 2-104 centipoise at 20 revolutions per minute.
Nach der vollständigen Durchtränkung des Schaumstoffes wird die überschüssige Aufschlämmung vom Schaumstoff entfernt, indem der imprägnierte Schaumstoff durch ein System von Walzenpaaren geführt wird. Danach wird der Schaumstoff getrocknet um das Wasser zu entfernen. DieAfter the foam has been completely saturated, the excess slurry is removed from the foam by passing the impregnated foam through a system of pairs of rollers. The foam is then dried to remove the water. The
Entfernung der organischen Substanz und des Restwassers kkaannnn dduurr<ch Erhitzen, beispielsweise auf über 225 C erfolgen.The organic substance and the residual water can be removed by heating, for example to above 225 ° C.
Besonders wirkungsvolle Filter können dadurch hergestellt werden, dass man sie einer Nach-Iinprägnierung unterwirft um die an der Oberfläche des Filters liegenden exponier¬ ten Zellstege gegen das Abbrechen zu sichern und um dem Filter eine erhöhte Temperaturbeständigkeit zu verleihen. Dazu wird der oben beschriebene, getrocknete und impräg¬ nierte Schaumstoff an der Oberfläche einer weiteren Imprägnierung mit einer keramischen Au schlämmung unter¬ worfen, nochmals getrocknet und zwecks Entfernung der organischen Substanz erhitzt und bei Temperaturen zwischen 1200° C und 1500° C, vorzugsweise zwischen 1350 C und 1450° C calziniert.Particularly effective filters can be produced by subjecting them to a re-impregnation in order to secure the exposed cell webs lying on the surface of the filter against breaking and to give the filter an increased temperature resistance. For this purpose, the dried and impregnated foam described above is subjected to a further impregnation with a ceramic slurry on the surface, dried again and heated to remove the organic substance and at temperatures between 1200 ° C and 1500 ° C, preferably between 1350 C and 1450 ° C calcined.
Diese Oberflächenimprägnierung kann entweder vor oder nach dem Brennvorgang erfolgen. Nach erfolgtem Brennvorgang wird der nachimprägnierte Keramikfilter bei Temperaturen zwischen 150° C und 600° C, vorzugsweise zwischen 250 C und 350 C getrocknet.This surface impregnation can take place either before or after the firing process. After the firing process, the impregnated ceramic filter is dried at temperatures between 150 ° C. and 600 ° C., preferably between 250 ° C. and 350 ° C.
Bei der Imprägnierung und Nachimprägnierung hat sich die Verwendung eines Netzmittels in einer Menge von beispiels¬ weise 0,5 - 2,0 Gew. % als vorteilhaft erwiesen.In the impregnation and post-impregnation, the use of a wetting agent in an amount of, for example, 0.5-2.0% by weight has proven to be advantageous.
Das thixotrope keramische Material kann gemäss vorstehen¬ den Ausführungen in einer Vielzahl von Rezepturen herge¬ stellt werden, besonders gute Resultate werden jedoch mit 65 % A1203, 3 % Kaolin, 1 % Alkylbenzolsulfonat als Netz¬ mittel, 25 % Monoaluminiumphosphat und 6 % Wasser erzielt.The thixotropic ceramic material can be produced according to the above in a variety of formulations, but particularly good results are obtained with 65% A1 2 0 3 , 3% kaolin, 1% alkylbenzenesulfonate as wetting agent, 25% monoaluminum phosphate and 6 % Water achieved.
Die Filter- erden vor oder in der Sandform bzw. der Kokille verwendet, wobei ein Einbau möglichst nahe am Gussstück er¬ folgen soll.The filter earths are used in front of or in the sand mold or the mold, with installation to be as close as possible to the casting.
In den beiliegenden Zeichnungen sind unterschiedliche Anordnungen eines Keramikfilters in einer Giessform dar¬ gestellt.Different arrangements of a ceramic filter in a casting mold are shown in the accompanying drawings.
Die Fig. 1 bis 6 zeigen Teilausschnitte der Hohlräume einer Form in perspektivischer Darstellung.1 to 6 show partial sections of the cavities of a mold in a perspective view.
Die Fig. 1 zeigt die Anordnung eines Keramikfilters 1 im Lauf 2 einer Giessform, wie z.B. einer Sandform, wobeiFig. 1 shows the arrangement of a ceramic filter 1 in the barrel 2 of a mold, such as a sand mold, where
OMPI der Lauf zwischen einem, einen Eingusstrichter aufweisenden Einguss 3 und dem weiter nicht dargestellten Formhohlraum angeordnet ist. Der vom Einguss 3 abzweigende erste Teil 2a des Laufes ist im Formunterteil angeordnet, wobei an dessen anderem erweiterten Ende der Keramikfilter 1 ange¬ ordnet ist. Der zweite Teil 2b des Laufes ist dann im Formoberteil angeordnet und führt von dem gezeigten er¬ weiterten, über dem Keramikfilter 1 angeordneten einem Ende zum Formhohlraum. Die in den Einguss 3 eingegossene Schmelze durchfliesst somit den Keramikfilter von unten nach oben wobei die gefilterte Schmelze durch den Teil 2b des Laufes in den Formhohlraum gelangt.OMPI the barrel is arranged between a sprue 3 having a sprue and the mold cavity (not shown). The first part 2a of the barrel branching off from the sprue 3 is arranged in the lower mold part, the ceramic filter 1 being arranged at the other widened end thereof. The second part 2b of the barrel is then arranged in the upper part of the mold and leads from the shown extended end, which is arranged above the ceramic filter 1, to the mold cavity. The melt poured into the sprue 3 thus flows through the ceramic filter from bottom to top, the filtered melt passing through part 2b of the barrel into the mold cavity.
Die Fig. 2 zeigt eine Anordnung, bei welcher der erste Teil 2a des Laufes 2 im Formoberteil und der zweite Teil 2b des Laufes 2 mit dem Keramikfilter 1 im Formunterteil angeordnet ist, wodurch die Schmelze den Keramikfilter von oben nach unten durchfliesst. In beiden Fällen ist der Keramikfilter sehr einfach von oben in den Formunter¬ teil einsetzbar.2 shows an arrangement in which the first part 2a of the barrel 2 is arranged in the upper mold part and the second part 2b of the barrel 2 with the ceramic filter 1 in the lower mold part, as a result of which the melt flows through the ceramic filter from top to bottom. In both cases, the ceramic filter can be inserted very easily into the lower part of the mold from above.
Fig. 3 zeigt die Anordnung eines als runde Platte ausge¬ bildeten Keramikfilters 1 zwischen dem Einguss 3 und dem zum Formhohlraum führenden Lauf 2, wobei der Filter 1 ebenfalls leicht in den mit dem Lauf 2 versehenen Form- - unterteil einsetzbar ist und von oben nach unten von der Schmelze durchflössen wird.3 shows the arrangement of a ceramic filter 1 designed as a round plate between the sprue 3 and the barrel 2 leading to the mold cavity, the filter 1 likewise being easily insertable into the mold base provided with the barrel 2 and from above is flowed through by the melt below.
Fig. 4 zeigt die Anordnung des Keramikfilters 1 zwischen dem Lauf 2 und einem darüber im Formoberteil angeordneten geschlossenen Speiser 4 - genannt auch Massel - von welchem die Schmelze direkt in den Formhohlraum des herzustellenden Gussstückes 5 gelangt. Der Keramikfilter 1 wird von der Schmelze von unten nach oben durchflössen und ist von oben in den Formunterteil einsetzbar.FIG. 4 shows the arrangement of the ceramic filter 1 between the barrel 2 and a closed feeder 4 - also called ingot - arranged above it in the upper part of the mold, from which the melt directly into the cavity of the mold to be produced Casting 5 arrives. The ceramic filter 1 is flowed through by the melt from bottom to top and can be inserted into the bottom part of the mold from above.
In dem in Fig. 5 gezeigten Ausführungsbeispiel ist der Keramikfilter 1 zwischen dem geschlossenen Speiser 4 und dem Formhohlraum für das Gussstück 5 angeordnet. Der plattenförmige Keramikfilter 1 ist in senkrechter Lage in den Formunterteil und/oder Formoberteil einsetzbar und dient gleichzeitig als vorgezeichnete Brechstelle - auch Brechkern genannt -' zur Trennung des Gussstückes 5 von dem aus Einguss 3, Lauf 2 und Speiser 4 bestehenden Eingusssystem.In the exemplary embodiment shown in FIG. 5, the ceramic filter 1 is arranged between the closed feeder 4 and the mold cavity for the casting 5. The plate-shaped ceramic filter 1 is used in a vertical position in the bottom mold part and / or upper mold and also serves as a pre-recorded breaking point - also called refractive core - 'for the separation of the casting 5 from the group consisting of sprue 3, Run 2 and Speiser 4 gating system.
Fig. 6 zeigt den direkten Einsatz eines Keramikfilters 1 zwischen dem Einlaufzapfen 3 und dem Gussstück 5, wobei hier ebenfalls der Keramikfilter 1 die vorgezeichnete Brechstelle bildet. Der Keramikfilter wird wie aus Fig. 6 ersichtlich von oben nach unten von der Schmelze durch¬ flössen wobei eine Anordnung am unteren Teil des Guss¬ stückes 5 mit Durchfluss von unten nach oben ebenfalls möglich ist. 6 shows the direct use of a ceramic filter 1 between the inlet spigot 3 and the casting 5, the ceramic filter 1 also forming the predetermined breaking point here. As can be seen from FIG. 6, the ceramic filter is flowed through by the melt from top to bottom, whereby an arrangement on the lower part of the casting 5 with a flow from bottom to top is also possible.
Claims
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI824075A FI824075A7 (en) | 1981-03-27 | 1982-03-26 | Ceramic filter, method of making it and its use. |
| AU82093/82A AU8209382A (en) | 1981-03-27 | 1982-03-26 | Ceramic filter, method for manufacturing and using this filter |
| BR8207248A BR8207248A (en) | 1981-03-27 | 1982-03-26 | CERAMIC FILTER PROCESS FOR ITS PRODUCTION AND USE |
| IN1086/CAL/82A IN158599B (en) | 1981-03-27 | 1982-09-20 |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH208981 | 1981-03-27 | ||
| CH2089/81810327 | 1981-03-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1982003339A1 true WO1982003339A1 (en) | 1982-10-14 |
Family
ID=4225633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CH1982/000048 Ceased WO1982003339A1 (en) | 1981-03-27 | 1982-03-26 | Ceramic filter,method for manufacturing and utilizing this filter |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0074978A1 (en) |
| JP (1) | JPS58500434A (en) |
| BR (1) | BR8207248A (en) |
| ES (1) | ES510842A0 (en) |
| IT (1) | IT1151368B (en) |
| WO (1) | WO1982003339A1 (en) |
| ZA (1) | ZA822136B (en) |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3305445A1 (en) * | 1983-02-11 | 1984-08-16 | Schweizerische Aluminium Ag, Chippis | CERAMIC PORED FILTER BODY AND A METHOD FOR PRODUCING THE SAME |
| EP0126847A1 (en) * | 1984-02-17 | 1984-12-05 | Georg Fischer Aktiengesellschaft | Ceramic filter |
| EP0234825A1 (en) * | 1986-02-25 | 1987-09-02 | Foseco International Limited | Casting of molten ferrous metal and moulds for use therein |
| EP0243217A1 (en) * | 1986-03-19 | 1987-10-28 | Ceramiques Et Composites | Process of production of a filter for liquid metals |
| US4713180A (en) * | 1984-02-15 | 1987-12-15 | Georg Fischer Aktiengesellschaft | Ceramic filter and method for using same |
| WO1988004587A1 (en) * | 1986-12-15 | 1988-06-30 | Schweizerische Aluminium Ag | Casting funnel for molten metals |
| EP0159963A3 (en) * | 1984-04-23 | 1988-09-07 | Schweizerische Aluminium Ag | Ceramic filter with an open cells foam structure |
| DE3901602A1 (en) * | 1988-02-12 | 1989-08-24 | Fischer Ag Georg | CASTING SYSTEM FOR A CASTING MOLD |
| EP0294970A3 (en) * | 1987-06-10 | 1989-11-29 | Foseco International Limited | Metal casting patterns |
| DE3905080C1 (en) * | 1989-02-18 | 1989-11-30 | Georg Fischer Ag, Schaffhausen, Ch | Ceramic filter for filtering metal melts |
| FR2641475A1 (en) * | 1989-01-11 | 1990-07-13 | Fischer Ag Georg | CERAMIC FILTER FOR FILTRATION OF FUSION METALS |
| US5033531A (en) * | 1989-07-26 | 1991-07-23 | Foseco International Limited | Casting of molten iron and filters for use therein |
| EP0507463A3 (en) * | 1991-04-05 | 1993-03-17 | Foseco International Limited | Filters for light metals |
| US7963402B2 (en) | 2005-09-05 | 2011-06-21 | Sud-Chemie Hi-Tech Ceramics Inc. | Filter device for molten metal filtration and method for producing such filters |
| CN103203431A (en) * | 2013-05-04 | 2013-07-17 | 日月重工股份有限公司 | Filter for casting |
| CN105689650A (en) * | 2016-04-28 | 2016-06-22 | 江苏锡华铸造有限公司 | Casting gating system with scum riser |
| CN110862269A (en) * | 2019-12-10 | 2020-03-06 | 萍乡市恒升特种材料有限公司 | Preparation method of high-strength foamed ceramic |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3090094A (en) * | 1961-02-21 | 1963-05-21 | Gen Motors Corp | Method of making porous ceramic articles |
| GB1377691A (en) * | 1973-01-03 | 1974-12-18 | Foseco Int | Porous ceramic materials |
| US3893917A (en) * | 1974-01-02 | 1975-07-08 | Alusuisse | Molten metal filter |
| FR2305407A1 (en) * | 1975-03-28 | 1976-10-22 | Alusuisse | CERAMIC FOAM FILTER, ESPECIALLY FOR THE FILTRATION OF MELTED METAL |
| FR2409785A1 (en) * | 1977-11-25 | 1979-06-22 | Alusuisse | METHOD AND DEVICE FOR FILTERING MELTED METAL |
| GB2027688A (en) * | 1978-08-12 | 1980-02-27 | Bridgestone Tire Co Ltd | Ceramic porous body |
-
1982
- 1982-03-26 BR BR8207248A patent/BR8207248A/en unknown
- 1982-03-26 IT IT20410/82A patent/IT1151368B/en active
- 1982-03-26 EP EP82900929A patent/EP0074978A1/en not_active Withdrawn
- 1982-03-26 JP JP57501015A patent/JPS58500434A/en active Pending
- 1982-03-26 WO PCT/CH1982/000048 patent/WO1982003339A1/en not_active Ceased
- 1982-03-26 ES ES510842A patent/ES510842A0/en active Granted
- 1982-03-29 ZA ZA822136A patent/ZA822136B/en unknown
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3090094A (en) * | 1961-02-21 | 1963-05-21 | Gen Motors Corp | Method of making porous ceramic articles |
| GB1377691A (en) * | 1973-01-03 | 1974-12-18 | Foseco Int | Porous ceramic materials |
| US3893917A (en) * | 1974-01-02 | 1975-07-08 | Alusuisse | Molten metal filter |
| FR2305407A1 (en) * | 1975-03-28 | 1976-10-22 | Alusuisse | CERAMIC FOAM FILTER, ESPECIALLY FOR THE FILTRATION OF MELTED METAL |
| FR2409785A1 (en) * | 1977-11-25 | 1979-06-22 | Alusuisse | METHOD AND DEVICE FOR FILTERING MELTED METAL |
| GB2027688A (en) * | 1978-08-12 | 1980-02-27 | Bridgestone Tire Co Ltd | Ceramic porous body |
Non-Patent Citations (1)
| Title |
|---|
| Foundry Management Technology, Vol. 7, No, 102, 1974, D.C. SWANSON 'New Method of Filtering Molten Aluminium' pages 94, 96, see the whole document * |
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3305445A1 (en) * | 1983-02-11 | 1984-08-16 | Schweizerische Aluminium Ag, Chippis | CERAMIC PORED FILTER BODY AND A METHOD FOR PRODUCING THE SAME |
| US4713180A (en) * | 1984-02-15 | 1987-12-15 | Georg Fischer Aktiengesellschaft | Ceramic filter and method for using same |
| EP0126847A1 (en) * | 1984-02-17 | 1984-12-05 | Georg Fischer Aktiengesellschaft | Ceramic filter |
| EP0159963A3 (en) * | 1984-04-23 | 1988-09-07 | Schweizerische Aluminium Ag | Ceramic filter with an open cells foam structure |
| EP0234825A1 (en) * | 1986-02-25 | 1987-09-02 | Foseco International Limited | Casting of molten ferrous metal and moulds for use therein |
| AU583446B2 (en) * | 1986-02-25 | 1989-04-27 | Foseco International Limited | Casting of molten ferrous metal and moulds for use therein |
| EP0466215A3 (en) * | 1986-03-19 | 1992-03-11 | Ceramiques Et Composites | Filter for liquid metals, based on alveolar ceramic material, process for the production thereof, and its use in filtering liquid metals or alloys having high melting points |
| EP0243217A1 (en) * | 1986-03-19 | 1987-10-28 | Ceramiques Et Composites | Process of production of a filter for liquid metals |
| FR2599990A1 (en) * | 1986-03-19 | 1987-12-18 | Ceramiques Composites | FILTER FOR LIQUID METALS BASED ON ALVEOLAR CERAMIC MATERIAL, PROCESS FOR PREPARING THE SAME AND APPLICATION THEREOF TO THE FILTRATION OF METALS OR LIQUID ALLOYS OF HIGH MELTING POINT |
| WO1988004587A1 (en) * | 1986-12-15 | 1988-06-30 | Schweizerische Aluminium Ag | Casting funnel for molten metals |
| EP0294970A3 (en) * | 1987-06-10 | 1989-11-29 | Foseco International Limited | Metal casting patterns |
| DE3901602A1 (en) * | 1988-02-12 | 1989-08-24 | Fischer Ag Georg | CASTING SYSTEM FOR A CASTING MOLD |
| FR2641475A1 (en) * | 1989-01-11 | 1990-07-13 | Fischer Ag Georg | CERAMIC FILTER FOR FILTRATION OF FUSION METALS |
| BE1002969A5 (en) * | 1989-01-11 | 1991-10-08 | Fischer Ag Georg | CERAMIC FILTER FOR FILTRATION OF FUSED METALS. |
| DE3905080C1 (en) * | 1989-02-18 | 1989-11-30 | Georg Fischer Ag, Schaffhausen, Ch | Ceramic filter for filtering metal melts |
| US5033531A (en) * | 1989-07-26 | 1991-07-23 | Foseco International Limited | Casting of molten iron and filters for use therein |
| EP0507463A3 (en) * | 1991-04-05 | 1993-03-17 | Foseco International Limited | Filters for light metals |
| US7963402B2 (en) | 2005-09-05 | 2011-06-21 | Sud-Chemie Hi-Tech Ceramics Inc. | Filter device for molten metal filtration and method for producing such filters |
| CN103203431A (en) * | 2013-05-04 | 2013-07-17 | 日月重工股份有限公司 | Filter for casting |
| CN105689650A (en) * | 2016-04-28 | 2016-06-22 | 江苏锡华铸造有限公司 | Casting gating system with scum riser |
| CN110862269A (en) * | 2019-12-10 | 2020-03-06 | 萍乡市恒升特种材料有限公司 | Preparation method of high-strength foamed ceramic |
Also Published As
| Publication number | Publication date |
|---|---|
| IT8220410A0 (en) | 1982-03-26 |
| ZA822136B (en) | 1983-03-30 |
| ES8306625A1 (en) | 1983-06-01 |
| ES510842A0 (en) | 1983-06-01 |
| IT1151368B (en) | 1986-12-17 |
| BR8207248A (en) | 1983-03-01 |
| JPS58500434A (en) | 1983-03-24 |
| EP0074978A1 (en) | 1983-03-30 |
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