CA2056992A1 - Process for preparing fibrous magnesium oxide - Google Patents
Process for preparing fibrous magnesium oxideInfo
- Publication number
- CA2056992A1 CA2056992A1 CA002056992A CA2056992A CA2056992A1 CA 2056992 A1 CA2056992 A1 CA 2056992A1 CA 002056992 A CA002056992 A CA 002056992A CA 2056992 A CA2056992 A CA 2056992A CA 2056992 A1 CA2056992 A1 CA 2056992A1
- Authority
- CA
- Canada
- Prior art keywords
- magnesium oxide
- magnesium
- fibrous
- calcination
- calcined
- 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.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/02—Magnesia
- C01F5/06—Magnesia by thermal decomposition of magnesium compounds
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/02—Magnesia
- C01F5/06—Magnesia by thermal decomposition of magnesium compounds
- C01F5/08—Magnesia by thermal decomposition of magnesium compounds by calcining magnesium hydroxide
-
- 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
- C04B2/00—Lime, magnesia or dolomite
- C04B2/10—Preheating, burning calcining or cooling
- C04B2/102—Preheating, burning calcining or cooling of magnesia, e.g. dead burning
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/03—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite
- C04B35/04—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite based on magnesium oxide
- C04B35/053—Fine ceramics
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/62227—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products obtaining fibres
- C04B35/62231—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products obtaining fibres based on oxide ceramics
- C04B35/62263—Fibres based on magnesium oxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Paper (AREA)
Abstract
A b s t r a c t :
A process for preparing fibrous magnesium oxide. One or several neutral magnesium carbonates containing water of crystallization, especially magnesium carbonate trihydrate, are precipitated from an aqueous solution in the form of needle-shaped particles and are then dried and calcined to give fibrous magnesium oxide with retaining the particle form.
A process for preparing fibrous magnesium oxide. One or several neutral magnesium carbonates containing water of crystallization, especially magnesium carbonate trihydrate, are precipitated from an aqueous solution in the form of needle-shaped particles and are then dried and calcined to give fibrous magnesium oxide with retaining the particle form.
Description
~ 20~699~
A Process for Preparing Fibrous Magnesium Oxide The present invention relates to a process for preparing fibrous magnesium oxide, in which a material in form of needle-shaped particles containing magnesium and water of crys-tallization is converted by calcining into fibrous magnesium oxide.
Magnesium oxide has a very high melting point und possesses a good chemical resistance to basic systems and also good electric insulating properties as well as a reasonable good thermal conductivity. Due to these properties it is used widely in different fields, especially as material for refractory bodies and 10 refractory bricks respectively for use in the metallurgical industry and as a filler for synthetic resins being capable of improving the thermal conductivi-ty o~ the synthetic resin material. Magnesium oxide usually consists of particles in granular form, i.e. particles having approximately the same 15 dimensions in different directions similar to cubes and spheres.
Also known is fibrous magnesium oxide, that means magnesium oxide, the particles of which have an elongated form, the ra-tio o~ the length of said particles to the greates-t average transverse dimension being at least 10 : 1 and -the sectional area of the 20 particles being less than 0,05 mm2 and the width of the particles being smaller than 0,25 mm (see also ASTM D 3878). Such particles of fibrous magnesium oxide have a reasonable high strength, so that a distinctly higher strength of bodies or bricks respectively consisting of magnesium oxide and used e.g. for the formation of 25 refractory linings, and especially of bodies of plastic materials containing magnesium oxide as filler may be achieved than in case of using the usual magnesium oxide in form of granular particles.
The known processes for preparing fibrous magnesium oxide show a number of disadvantages, such as e.g. a low performance, 30 the production costs at the same time being burdened by a great expendi-ture of energy, and a relatively complicated procedure involving intermediates formed by slow reactions, as well as the additional serious disadvantage that corrosive and toxic gases are formed in the reaction of said intermedia-tes to give the fibrous 35 magnesium oxide, the disposal of said gases being difficult and increasing the costs of the process. Such a known process involves 20~992 the precipitation of magnesium oxide from the vapor phase preceded by the reaction of magnesium metal vapor with oxygen so as to form magnesium oxide, and during the precipitation of the magnesium oxide from the vapor phase fibrous particles of magnesium oxide are formed. This process has a relatively low performance and requires a great expenditure of energy. In another known process needle-shaped basic intermediate magnesium compounds having a monovalent to -tetravalent anion and containing water of crystallization are formed, which intermediate products then are converted by calcination into fibrous magnesium oxide or first magnesium hydroxide is prepared from such an intermediate produc-t and then the fibrous magnesium oxide is formed therefrom. The preparation of said basic magnesium compounds is complicated and corrosive or toxic gases are liberated in the calcination thereof rendering the process more complicated due to the inevitable disposal of said gases.
It is an object of the present invention to provide a process as mentioned above, which may be carried out as simple as possible and with low expenditure of costs and which is efficient quantita--tively and does not cause grea-ter problems with by-products formed in the process.
The present invention provides a process for preparing fibrous magnesium oxide, in which a material in form of needle-shaped particles containing magnesium and water of crystallization is converted into fibrous magnesium oxide by calcina-tion, wherein one or several neutral magnesium carbonates con-taining water of crystallization and having the formula MgCO3.x~2O, in which l s x s 5, especially magnesium carbonate trihydrate, are used as material to be calcined.
The above mentioned object may be achieved by said process.
Neutral magnesium carbonates containing water of crystallization, especially magnesium carbonate trihydrate, may be obtained relatively easily, e.g. by precipi-tating solutions of magnesium salts with ammonia and carbon dioxide, ammonium carbonate and ammonium hydrogen carbonate respectively or by carboniza-tion of precipitated magnesium hydroxide. Thus e.g. magnesium carbonate -trihydrate in form of needle-shaped crystals can be precipitated simply and rapidly from an aqueous solution, the size of the 2~5~92 crystals being influenceable by choice of the temperature of the reactor. Said temperature is only slightly above ambient temperature and does not require any constructional special provisions or energetical expenditure.
The neutral magnesium carbonates containing water of crystallization can be calcined in a simple manner to give fibrous magnesium oxide with largely retaining the particle form. In said calcination process toxically or corrosively acting products are not formed. The calcination temperature may be selected within broad ranges. Good results are obtained at calcination tempera-tures of between 350 and 2000~C. Preferably calcination tempera-tures of between 800 and 1600C are used. Depending on the device used for the calcination very short calcination periods of e.g.
few seconds up to long calcination periods of several hours are employed. Suitably the material to be calcined is dried in vacuo at a temperature of below 100C or partially dehydra-ted respectively before calcination.
In the process of the invention preferably the heating up of the material to be calcined is effected with a rate of less than 10C/minute. This resul-ts in a gentle progress of the calcina-tion, which favors the conversion of the neutral magnesium carbonates into fibrous magnesium oxide.
The particles of the fibrous magnesium oxide prepared by the process of the invention have a high strength. Higher strength values may be achieved here than in case of particles of fibrous magnesium oxide prepared in known manner from basic magnesium compounds. Thus, if fibrous magnesium oxide prepared by the process of the invention is used as a filler of synthetic resins a considerable improvement of the strength of the filled plas-tic rnaterial may be achieved already wi-th relatively small amounts of filler.
The following examples illustrate the invention further.
Example 1:
500 ml of distilled water were filled into a stirred vessel provided with thermostatic means and 500 ml of a solution of magnesium chloride containing 298 g/litre of MgCl2 were added and the mixture was heated to 35~C. The solution was intensively mixed by means of a stirrer and 213 g of a 25 % solution of ammonia were 2 ~ 9 2 dropped in over a period of 30 minutes and 35 litres of C02 were introduced into the solution. The reaction mixture was maintained at a temperature of 40C by means of a heat exchanger. After complete reaction the suspension was filtered, the filter cake was washed with water and the obtained product was dried at low temperatures of below 40C in vacuo. The product was identified as nesquehonite, MgC03.3H20, and had the appearance of needle-shaped crystals.
Scanning electron micrographs showed -that the needles of nesquehoni-te had a length of about 150 ~m and an average diameter of about 5 ~m.
The product thus obtained was calcined at a -temperature of 1100C for 3 hours to give fibrous magnesium oxide. The synthe-tized fibres similarly to the used startiny fibres of nesquehonite had a length of about 150 ~m and an average diameter of about 5 ~m. By means of X-ray diffraction the product could be identi-fied as magnesium oxide.
E mple 2:
The process of example 1 was repeated, however, the filter cake obtained after complete reaction and filtration of the suspension and washed wi-th water was dried in vacuo at a temperature of 70C for 2 hours. Chemical analysis showed that a neutral magnesium carbonate having the composition MgC03.2,4H20 had been formed. Scanning electron micrographs showed that th obtained product was composed of fibres having a length of about 150 ~m and an average diame-ter of about 5 ~m.
The produc-t obtained in this manner was heated to a temperature of 850C with a heating rate of 3C/minute and was cooled without control after a holding time of 1 hour. A fibrous substance having fibres with lengths of about 150 ~m and average diameters of about 5 ~Im was obtained. X-rax diffraction confirmed that the material was magnesium oxide.
Example 3:
The product of example 1 iden-tified as nesquehonite, MgC03.3H20, and having the appearance oE needle~shaped crystals was heated to a temperature of 1600C with a heating ra-te of 5C/minute and was cooled without control after a holding time of 20~6~
1 hour. By means of X-ray diffraction the fibrous product could be identified as magnesium oxide. Similarly to the used nesquihonite the fibre lengths were 50 to 150 ~m and the average fibre 5 diameters 2 to 5 ~m.
Example 4:
The neutral magnesium carbonate of example 2 having the composition MgCO3.2.4H20 was heated to a temperature of 400C with lOa heating rate of 10C/minute. ~f-ter a holding time of 3 hours fibrous magnesium oxide was obtained. The synthetized fibres did not dif-fer morphologically from the used neutral magnesium carbonate and showed fibre lengths of up to 150 ~m and average fibre diameters of about 3 to 5 ~m. X-ra~ diffraction confirmed 15 tha-t the product was ~agnesium oxide.
Example 5: Use of Mg-fibres for improving the strength of composites The MgO-fibres obtained in example 1 as well as silicon carbide whiskers and commercially available magnesium oxide were 20embedded into an epoxy resin in amounts of 4 % by volume and the flexural strength at break was examined on test specimens. The results of these tests are summarized in table 1. It results that the MgO-fibres effect a significan-t improvement of the flexural strength at break of the composites already in small amounts. If 25 the flexural strength at break of the composites is compared among one another and with that of the pure epoxy resin, -taking the mixing standard as a basis and assuming an isotropic distribution of the fibres in the matrix, an intrinsic strength of the MgO-fibres of the invention of about 7000 to 8000 MPa will be 30 calcula-ted.
T a b 1 e Strength of composites containing 4 % by volume of filler Flexural streng-th Matrix Reinforcing componentat break MPa Epoxy resin - 44 epoxy resin silicon carbide whisker 84 epoxy resin MgO-fibres of the invention 62 epoxy resin commercially available MgO 49
A Process for Preparing Fibrous Magnesium Oxide The present invention relates to a process for preparing fibrous magnesium oxide, in which a material in form of needle-shaped particles containing magnesium and water of crys-tallization is converted by calcining into fibrous magnesium oxide.
Magnesium oxide has a very high melting point und possesses a good chemical resistance to basic systems and also good electric insulating properties as well as a reasonable good thermal conductivity. Due to these properties it is used widely in different fields, especially as material for refractory bodies and 10 refractory bricks respectively for use in the metallurgical industry and as a filler for synthetic resins being capable of improving the thermal conductivi-ty o~ the synthetic resin material. Magnesium oxide usually consists of particles in granular form, i.e. particles having approximately the same 15 dimensions in different directions similar to cubes and spheres.
Also known is fibrous magnesium oxide, that means magnesium oxide, the particles of which have an elongated form, the ra-tio o~ the length of said particles to the greates-t average transverse dimension being at least 10 : 1 and -the sectional area of the 20 particles being less than 0,05 mm2 and the width of the particles being smaller than 0,25 mm (see also ASTM D 3878). Such particles of fibrous magnesium oxide have a reasonable high strength, so that a distinctly higher strength of bodies or bricks respectively consisting of magnesium oxide and used e.g. for the formation of 25 refractory linings, and especially of bodies of plastic materials containing magnesium oxide as filler may be achieved than in case of using the usual magnesium oxide in form of granular particles.
The known processes for preparing fibrous magnesium oxide show a number of disadvantages, such as e.g. a low performance, 30 the production costs at the same time being burdened by a great expendi-ture of energy, and a relatively complicated procedure involving intermediates formed by slow reactions, as well as the additional serious disadvantage that corrosive and toxic gases are formed in the reaction of said intermedia-tes to give the fibrous 35 magnesium oxide, the disposal of said gases being difficult and increasing the costs of the process. Such a known process involves 20~992 the precipitation of magnesium oxide from the vapor phase preceded by the reaction of magnesium metal vapor with oxygen so as to form magnesium oxide, and during the precipitation of the magnesium oxide from the vapor phase fibrous particles of magnesium oxide are formed. This process has a relatively low performance and requires a great expenditure of energy. In another known process needle-shaped basic intermediate magnesium compounds having a monovalent to -tetravalent anion and containing water of crystallization are formed, which intermediate products then are converted by calcination into fibrous magnesium oxide or first magnesium hydroxide is prepared from such an intermediate produc-t and then the fibrous magnesium oxide is formed therefrom. The preparation of said basic magnesium compounds is complicated and corrosive or toxic gases are liberated in the calcination thereof rendering the process more complicated due to the inevitable disposal of said gases.
It is an object of the present invention to provide a process as mentioned above, which may be carried out as simple as possible and with low expenditure of costs and which is efficient quantita--tively and does not cause grea-ter problems with by-products formed in the process.
The present invention provides a process for preparing fibrous magnesium oxide, in which a material in form of needle-shaped particles containing magnesium and water of crystallization is converted into fibrous magnesium oxide by calcina-tion, wherein one or several neutral magnesium carbonates con-taining water of crystallization and having the formula MgCO3.x~2O, in which l s x s 5, especially magnesium carbonate trihydrate, are used as material to be calcined.
The above mentioned object may be achieved by said process.
Neutral magnesium carbonates containing water of crystallization, especially magnesium carbonate trihydrate, may be obtained relatively easily, e.g. by precipi-tating solutions of magnesium salts with ammonia and carbon dioxide, ammonium carbonate and ammonium hydrogen carbonate respectively or by carboniza-tion of precipitated magnesium hydroxide. Thus e.g. magnesium carbonate -trihydrate in form of needle-shaped crystals can be precipitated simply and rapidly from an aqueous solution, the size of the 2~5~92 crystals being influenceable by choice of the temperature of the reactor. Said temperature is only slightly above ambient temperature and does not require any constructional special provisions or energetical expenditure.
The neutral magnesium carbonates containing water of crystallization can be calcined in a simple manner to give fibrous magnesium oxide with largely retaining the particle form. In said calcination process toxically or corrosively acting products are not formed. The calcination temperature may be selected within broad ranges. Good results are obtained at calcination tempera-tures of between 350 and 2000~C. Preferably calcination tempera-tures of between 800 and 1600C are used. Depending on the device used for the calcination very short calcination periods of e.g.
few seconds up to long calcination periods of several hours are employed. Suitably the material to be calcined is dried in vacuo at a temperature of below 100C or partially dehydra-ted respectively before calcination.
In the process of the invention preferably the heating up of the material to be calcined is effected with a rate of less than 10C/minute. This resul-ts in a gentle progress of the calcina-tion, which favors the conversion of the neutral magnesium carbonates into fibrous magnesium oxide.
The particles of the fibrous magnesium oxide prepared by the process of the invention have a high strength. Higher strength values may be achieved here than in case of particles of fibrous magnesium oxide prepared in known manner from basic magnesium compounds. Thus, if fibrous magnesium oxide prepared by the process of the invention is used as a filler of synthetic resins a considerable improvement of the strength of the filled plas-tic rnaterial may be achieved already wi-th relatively small amounts of filler.
The following examples illustrate the invention further.
Example 1:
500 ml of distilled water were filled into a stirred vessel provided with thermostatic means and 500 ml of a solution of magnesium chloride containing 298 g/litre of MgCl2 were added and the mixture was heated to 35~C. The solution was intensively mixed by means of a stirrer and 213 g of a 25 % solution of ammonia were 2 ~ 9 2 dropped in over a period of 30 minutes and 35 litres of C02 were introduced into the solution. The reaction mixture was maintained at a temperature of 40C by means of a heat exchanger. After complete reaction the suspension was filtered, the filter cake was washed with water and the obtained product was dried at low temperatures of below 40C in vacuo. The product was identified as nesquehonite, MgC03.3H20, and had the appearance of needle-shaped crystals.
Scanning electron micrographs showed -that the needles of nesquehoni-te had a length of about 150 ~m and an average diameter of about 5 ~m.
The product thus obtained was calcined at a -temperature of 1100C for 3 hours to give fibrous magnesium oxide. The synthe-tized fibres similarly to the used startiny fibres of nesquehonite had a length of about 150 ~m and an average diameter of about 5 ~m. By means of X-ray diffraction the product could be identi-fied as magnesium oxide.
E mple 2:
The process of example 1 was repeated, however, the filter cake obtained after complete reaction and filtration of the suspension and washed wi-th water was dried in vacuo at a temperature of 70C for 2 hours. Chemical analysis showed that a neutral magnesium carbonate having the composition MgC03.2,4H20 had been formed. Scanning electron micrographs showed that th obtained product was composed of fibres having a length of about 150 ~m and an average diame-ter of about 5 ~m.
The produc-t obtained in this manner was heated to a temperature of 850C with a heating rate of 3C/minute and was cooled without control after a holding time of 1 hour. A fibrous substance having fibres with lengths of about 150 ~m and average diameters of about 5 ~Im was obtained. X-rax diffraction confirmed that the material was magnesium oxide.
Example 3:
The product of example 1 iden-tified as nesquehonite, MgC03.3H20, and having the appearance oE needle~shaped crystals was heated to a temperature of 1600C with a heating ra-te of 5C/minute and was cooled without control after a holding time of 20~6~
1 hour. By means of X-ray diffraction the fibrous product could be identified as magnesium oxide. Similarly to the used nesquihonite the fibre lengths were 50 to 150 ~m and the average fibre 5 diameters 2 to 5 ~m.
Example 4:
The neutral magnesium carbonate of example 2 having the composition MgCO3.2.4H20 was heated to a temperature of 400C with lOa heating rate of 10C/minute. ~f-ter a holding time of 3 hours fibrous magnesium oxide was obtained. The synthetized fibres did not dif-fer morphologically from the used neutral magnesium carbonate and showed fibre lengths of up to 150 ~m and average fibre diameters of about 3 to 5 ~m. X-ra~ diffraction confirmed 15 tha-t the product was ~agnesium oxide.
Example 5: Use of Mg-fibres for improving the strength of composites The MgO-fibres obtained in example 1 as well as silicon carbide whiskers and commercially available magnesium oxide were 20embedded into an epoxy resin in amounts of 4 % by volume and the flexural strength at break was examined on test specimens. The results of these tests are summarized in table 1. It results that the MgO-fibres effect a significan-t improvement of the flexural strength at break of the composites already in small amounts. If 25 the flexural strength at break of the composites is compared among one another and with that of the pure epoxy resin, -taking the mixing standard as a basis and assuming an isotropic distribution of the fibres in the matrix, an intrinsic strength of the MgO-fibres of the invention of about 7000 to 8000 MPa will be 30 calcula-ted.
T a b 1 e Strength of composites containing 4 % by volume of filler Flexural streng-th Matrix Reinforcing componentat break MPa Epoxy resin - 44 epoxy resin silicon carbide whisker 84 epoxy resin MgO-fibres of the invention 62 epoxy resin commercially available MgO 49
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for preparing fibrous magnesium oxide, in which a material in form of needle-shaped particles containing magnesium and water of crystallization is converted into fibrous magnesium oxide by calcination, wherein one or several neutral magnesium carbonates containing water of crystallization and having the formula MgCO3.xH2O, in which 1 ? x ? 5, especially magnesium carbonate trihydrate, are used as material to be calcined.
2. The process of claim 1, wherein the material to be calcined is dried and partially dehydrated respectively in vacuo at a temperature of below 100°C.
3. The process of claim 1 or 2, wherein the calcination is carried out at a temperature of between 350 and 2000°C, preferably between 800 and 1600°C.
4. The process of one of claims 1 to 3, wherein in the calcination the heating up of the material to be calcined is effected with a rate of less than 10°C/minute.
5. Use of the fibrous magnesium oxide prepared according to the process of one of claims 1 to 4 as reinforcing component in plastic material and/or metal and/or ceramic composites.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT0068290A AT393677B (en) | 1990-03-22 | 1990-03-22 | METHOD FOR PRODUCING FIBROUS MAGNESIUM OXIDE |
| ATA682/90 | 1990-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2056992A1 true CA2056992A1 (en) | 1991-09-23 |
Family
ID=3497042
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002056992A Abandoned CA2056992A1 (en) | 1990-03-22 | 1991-03-07 | Process for preparing fibrous magnesium oxide |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0473762A1 (en) |
| JP (1) | JPH0723216B2 (en) |
| KR (1) | KR920701045A (en) |
| AT (1) | AT393677B (en) |
| AU (1) | AU7546991A (en) |
| BR (1) | BR9105100A (en) |
| CA (1) | CA2056992A1 (en) |
| HU (1) | HUT60223A (en) |
| WO (1) | WO1991014659A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2418241B1 (en) | 2010-08-12 | 2016-02-17 | Bene_fit Systems GmbH & Co. KG | Filling material for compound materials containing magnesium carbonate, method for its production and application |
| JP6284099B2 (en) * | 2014-03-05 | 2018-02-28 | 国立研究開発法人産業技術総合研究所 | Resin composition for dielectric and high frequency dielectric device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3371993A (en) * | 1964-12-21 | 1968-03-05 | Corning Glass Works | Method of making magnesium oxide fibers |
| JPS6011223A (en) * | 1983-06-27 | 1985-01-21 | Kyowa Chem Ind Co Ltd | Fibrous magnesium oxide and its manufacture |
| JPS63162560A (en) * | 1986-12-25 | 1988-07-06 | 三菱マテリアル株式会社 | Magnesia whisker reinforced inorganic material |
-
1990
- 1990-03-22 AT AT0068290A patent/AT393677B/en not_active IP Right Cessation
-
1991
- 1991-03-07 KR KR1019910701362A patent/KR920701045A/en not_active Application Discontinuation
- 1991-03-07 EP EP91906525A patent/EP0473762A1/en not_active Withdrawn
- 1991-03-07 CA CA002056992A patent/CA2056992A1/en not_active Abandoned
- 1991-03-07 JP JP3506244A patent/JPH0723216B2/en not_active Expired - Lifetime
- 1991-03-07 AU AU75469/91A patent/AU7546991A/en not_active Abandoned
- 1991-03-07 HU HU914085A patent/HUT60223A/en unknown
- 1991-03-07 BR BR919105100A patent/BR9105100A/en not_active Application Discontinuation
- 1991-03-07 WO PCT/AT1991/000041 patent/WO1991014659A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| KR920701045A (en) | 1992-08-11 |
| AU7546991A (en) | 1991-10-21 |
| ATA68290A (en) | 1991-05-15 |
| HU914085D0 (en) | 1992-07-28 |
| EP0473762A1 (en) | 1992-03-11 |
| BR9105100A (en) | 1992-06-02 |
| HUT60223A (en) | 1992-08-28 |
| JPH0723216B2 (en) | 1995-03-15 |
| WO1991014659A1 (en) | 1991-10-03 |
| JPH04503797A (en) | 1992-07-09 |
| AT393677B (en) | 1991-11-25 |
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