Classifications

• • 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
• • 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
• • 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
• • 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.

Landscapes

• 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)
• Structural Engineering (AREA)
• Inorganic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Filtering Materials (AREA)
• Casting Support Devices, Ladles, And Melt Control Thereby (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4225633

Family Applications (1)

Country Status (7)

Cited By (17)

Citations (6)

• 1982
  • 1982-03-26 IT IT20410/82A patent/IT1151368B/it active
  • 1982-03-26 WO PCT/CH1982/000048 patent/WO1982003339A1/de not_active Application Discontinuation
  • 1982-03-26 EP EP82900929A patent/EP0074978A1/de not_active Withdrawn
  • 1982-03-26 BR BR8207248A patent/BR8207248A/pt unknown
  • 1982-03-26 ES ES510842A patent/ES8306625A1/es not_active Expired
  • 1982-03-26 JP JP57501015A patent/JPS58500434A/ja active Pending
  • 1982-03-29 ZA ZA822136A patent/ZA822136B/xx unknown

Patent Citations (6)

Non-Patent Citations (1)

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