WO1998027010A1 - Synthesis of aluminium and titanium compounds - Google Patents

Synthesis of aluminium and titanium compounds Download PDF

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Publication number
WO1998027010A1
WO1998027010A1 PCT/NZ1997/000169 NZ9700169W WO9827010A1 WO 1998027010 A1 WO1998027010 A1 WO 1998027010A1 NZ 9700169 W NZ9700169 W NZ 9700169W WO 9827010 A1 WO9827010 A1 WO 9827010A1
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Prior art keywords
titanium
aluminium
reaction
solvent
amorphous
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PCT/NZ1997/000169
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French (fr)
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Timothy Kemmitt
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Industrial Research Limited
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Priority to AU54195/98A priority Critical patent/AU5419598A/en
Publication of WO1998027010A1 publication Critical patent/WO1998027010A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • C01G23/04—Oxides; Hydroxides
    • C01G23/047—Titanium dioxide
    • C01G23/053—Producing by wet processes, e.g. hydrolysing titanium salts
    • 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
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C01F7/34—Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts
    • C01F7/36—Preparation of aluminium hydroxide by precipitation from solutions containing aluminium salts from organic aluminium salts
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • C01G23/003—Titanates
    • C01G23/006—Alkaline earth titanates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • C01G23/04—Oxides; Hydroxides
    • C01G23/047—Titanium dioxide
    • C01G23/053—Producing by wet processes, e.g. hydrolysing titanium salts
    • C01G23/0532—Producing by wet processes, e.g. hydrolysing titanium salts by hydrolysing sulfate-containing salts
    • 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
    • C04B35/46—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 titanium oxides or titanates
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
    • C07F7/003—Compounds containing elements of Groups 4 or 14 of the Periodic Table without C-Metal linkages
    • 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
    • C22B34/00—Obtaining refractory metals
    • C22B34/10—Obtaining titanium, zirconium or hafnium
    • C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
    • C22B34/1236—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching
    • C22B34/1259—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining titanium or titanium compounds from ores or scrap by wet processes, e.g. by leaching treatment or purification of titanium containing solutions or liquors or slurries
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/02—Amorphous compounds
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/80—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
    • C01P2002/86—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by NMR- or ESR-data
    • 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
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/582—Recycling of unreacted starting or intermediate materials

Definitions

  • the invention relates to a method of producing aluminium and titanium complexes. These complexes are convenient for use in further processing such as in preparing ceramics.
  • the two major sources of titanium in nature are the minerals ilmenite, (FeTiOs) and rutile, (Ti0 2 ).
  • Other sources also exist such as perovskite, (CaTi ⁇ 3), sphene, (CaTiSiOs), geikelite, (MgTi0 ), anatase, (Ti0 2 ) and brookite (Ti0 2 ).
  • Other ion titanium oxide phases eg pseudorutile, leucoxene, pseudobrookite and synthetic titanium containing slags are also important as raw materials.
  • the standard routes of processing ore are dependent of the Ti ⁇ 2 content.
  • High grade ore generally Ti0 2 >85% normally rutile
  • Lower grade ore is generally processed via the sulfate route.
  • Low grade ore 50-60% Ti0 2 content
  • the two main processing routes i.e. the sulfate route and the chloride process
  • the two main processing routes i.e. the sulfate route and the chloride process
  • Ilmenite or similar material with a high ion content is heated with hot sulfuric acid.
  • Ferrous sulfate (copperas) is precipitated and filtered.
  • the filtrate is concentrated and heated under conditions to precipitate controlled particle size anatase pulp, which can be washed, de-watered and fired to form synthetic anatase or rutile.
  • the major use for the titanium dioxide produced is in paints and pigments.
  • High grade ore is chlorinated in a fluidised bed reactor in the presence of coke at high temperature:
  • the chloride process is more compact than the sulfate route, the by-products are considerably less and a purer product can be obtained.
  • high temperature and corrosion problems and also toxicity hazards due to the use of large amounts of chlorine, the formation of titanium tetrachloride and to the waste products of the chlorination.
  • Ti0 2 is used as a white pigment and is generally made by hydrolysis of titanium sulfate or vapour-phase oxidation of TiCl with oxygen.
  • High purity titanium based chemicals are usually prepared from TiCl 4 that has been purified by repeated distillation.
  • titanium alkoxides and other sol-gel precursors are prepared from TiCl .
  • R is commonly isopropyl, n-propyl or n-butyl.
  • complexes of titanium can be prepared from rutile or anatase via a modified sulfate route using the chelating ligand catechol (ref J A Davies ⁇ S Dutremez J. Am. Ceram. Soc, 73 (1990), 1429). Calcination of the compound Ba(Ti(catecholate)3).3H 2 0 yielded BaTi0 3 powder.
  • the excellent chelating ability of catechol means that a relatively pure starting material must be used to prevent ion impurities being carried into the product.
  • sodium, potassium or barium titanates can be prepared from rutile or anatase via ethylene glycolate complexes (ref.
  • Aluminium alkoxides can be prepared from the chloride, AICI3 which is produced from the reaction of CI 2 with aluminium metal, or directly from aluminium metal using a catalyst (HgCh).
  • the industrial preparation of aluminium is via the highly energy intensive electrolytic method in molten cryolite at 800- 1000C.
  • the invention in a first aspect comprises a method for preparing an aluminium containing complex or complexes from an aluminium source by reacting said source with a solvent consisting essentially of aminoalcohol(s) .
  • the solvent consists essentially of triethanolamine, diethanolamine, or N- methyldiethanolamine, or mixtures of these.
  • the aluminium source is bauxite, boehmite or pseudo-boehmite.
  • the complex(es) formed are alumatrane complex(es)
  • the invention in a second aspect comprises a method for preparing a titanium containing complex or complexes from a titanium source by reacting said source with a solvent consisting essentially of aminoalcohol(s) .
  • said titanium source is amorphous.
  • the titanium source is amorphous titanium oxyhydroxide.
  • the method includes, as a preliminary step, the preparation of amorphous titaniu oxyhydroxide.
  • This preliminary preparative step will preferably involve base-precipitation from a titanium salt or complex solution, conveniently aqueous titanyl sulphate. Most preferably, the base employed will be ammonia, which will be added in excess. Alternatively, the preliminary preparative step will involve hydrolysis of a hydrolysable titanium source such as a titanium salt, titanium complex or titanium alkoxide.
  • a titanium salt or complex solution conveniently aqueous titanyl sulphate.
  • the base employed will be ammonia, which will be added in excess.
  • the preliminary preparative step will involve hydrolysis of a hydrolysable titanium source such as a titanium salt, titanium complex or titanium alkoxide.
  • the amorphous titanium oxyhydride starting material is washed, conveniently with distilled water, and retained moist as a wet slurry.
  • the amorphous titanium oxyhydride is dried, for example at 100°C.
  • the solvent consists essentially of triethanolamine, diethanolamine or N-methyldiethanolamine, or mixtures of these.
  • the complex(es) formed are titanatrane complex(es).
  • a base catalyst can be present in the reaction mix. This can be an alkali metal base catalyst or an alkaline earth base catalyst.
  • the alkali metal base catalyst is present and more preferably is selected from the Li, Na, K, or Cs oxides or hydroxides.
  • reaction is carried out at a temperature of between about 100°C and 260°C (inclusive).
  • reaction time is between 5 minutes and 48 hours, more preferably 2- 24 hours.
  • the reaction is effected under subatmospheric pressure, preferably at a pressure between 5 and 750 torr, most preferably at a pressure between 10 and 50 torr.
  • the reaction is effected at atmospheric pressure in the presence of an inert gas.
  • the invention also provides aluminium- and titanium-containing complexes obtained by the methods described above.
  • the process of the invention converts an aluminium or titanium source into convenient forms of aluminium- or titanium- containing complexes for further processing. This is achieved through the reaction of the source material (such as boehmite, bauxite, or rutile) with a solvent which does not include glycols but which instead consists of aminoalcohol(s).
  • the source material such as boehmite, bauxite, or rutile
  • a solvent which does not include glycols but which instead consists of aminoalcohol(s).
  • aminoalcohor as used herein, is meant a compound of formula (I):
  • Ri and R 2 are independently selected from C2-C3 alkylene groups and X is selected from hydrogen, alkyl and R3OH wherein R3 is a C2-C3 alkylene group.
  • Examples include triethanolamine, diethanolamine and N-alkyl diethanolamines for example N-methyldiethanolamine, with triethanolamine, diethanolamine and N- methyldiethanolamine being preferred.
  • the aminoalcohol solvent which is currently most preferred is triethanolamine.
  • the solvent can comprise one aminoalcohol only, or a mixture of two or more aminoalcohols. Aminoalcohol solvents suitable for use in the invention are readily available from commercial sources.
  • a base catalyst can be employed to decrease the reaction time. While not critical to the process, use of such a catalyst is therefore indicated where it is necessary or desirable to quickly produce the aluminium- or titanium-containing complex.
  • the base catalyst used in the reaction may be an alkali metal or alkaline earth hydroxide or oxide, with lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, barium hydroxide or calcium hydroxide being preferred. Again, these are readily available from commercial sources.
  • the basic reaction for the preparation of alumatranes from an aluminium source can be represented by:
  • TEAH3 triethanolamine, as a representative, although preferred, aminoalcohol.
  • the reagents are preferably mixed in a distillation setup which is thoroughly flushed with an inert gas; usually argon or nitrogen, although other gases as will be known in the art may be used.
  • an inert gas usually argon or nitrogen, although other gases as will be known in the art may be used.
  • the mixture is heated and allowed to react, with the water being removed continuously.
  • the reaction is preferably run with an excess of the aminoalcohol solvent which, as indicated above, is usually triethanolamine.
  • the reaction is conducted at or near the boiling point of the aminoalcohol (or, where a mixture of aminoalcohols is used, at or near the boiling point of the mixture). Therefore, when triethanolamine is used, the upper limit of the temperature range will be approximately 260°C. Preferably the temperature range will be between 100°C and 260°C and more preferably between 200°C and 250°C.
  • the pressure at which the reaction is carried out can also be varied. While the reaction proceeds satisfactorily at atmospheric pressure (desirably in the presence of an inert gas as described above), it is also effective at subatmospheric pressures (less than 760 torr, including at pressures which are significantly subatmospheric). Conveniently, the pressure can be between 5 and 750 torr. More conveniently, the pressure will be between 10 and 50 torr.
  • Carrying out the reaction under reduced pressure has a number of advantages, including that it facilitates removal of water produced in the reaction and allows lowering the temperature of the reaction.
  • the reaction temperature is between 100 and 260°C, and more preferably between 100 and 160°C.
  • the process of the invention can proceed as outlined above, it is preferred that it commence with the starting aluminium or titanium source in a particular form.
  • the titanium source which is preferably amorphous, and more preferably in the form of amorphous titanium oxyhydroxide.
  • the material is amorphous, thus exhibiting no lines in an X-ray diffraction (XRD) diffractogram.
  • the amorphous titanium oxyhydroxide starting material can be prepared by a number of processes.
  • the starting material can be prepared by hydrolysis of a hydrolysable titanium source. This can occur at acid, base or neutral pH and involve hydrolysis of, for example, a titanium salt, titanium complex or titanium alkoxide.
  • the amorphous titanium oxyhydroxide starting material be prepared by base precipitation, for example from a titanium salt or complex solution.
  • the base used will be ammonia although this is by no means to be interpreted as anything other than illustrative.
  • Titania gels, powders, sols or other particulate precipitates can be prepared for application as a starting material for the process.
  • Exemplary reaction schemes are as follows:
  • the amorphous titanium oxyhydroxide hydrate is washed thoroughly, preferably with distilled water to remove any soluble impurities. Presence of sulphate, chloride or other ions in the washings can be detected by standard analytical methods as will be known in the art as desired.
  • the product can be dried (conveniently at 100°C). It is however more preferred that the starting material be retained as a wet slurry. The applicants have found that as a moist or wet slurry, the amorphous titanium oxyhydroxide exhibits much greater reactivity in further reaction steps. This is therefore viewed as highly desirable, although by no means essential.
  • the process to which the present invention is directed makes the reaction simpler than prior art processes, allowing for more straightforward recycling of excess reagents, and allows the reaction to be carried out at higher temperature, increasing the reaction rate.
  • the addition of the optional catalyst further increases the reaction rate by increasing the basicity of the reaction mixture.
  • the yield includes polymerised triethanolamine together with the aluminate complex.
  • the complex is soluble in many organic solvents, and does not precipitate alumina on addition of water, which makes it an ideal ceramic or sol-gel precursor, or component thereof, having excellent storage and handling characteristics.
  • This preferred starting materical can be prepared by either of the following approaches.
  • Titanium tetratsopropoxide 28.4g, 0. 1 mol was treated with excess water (100 cm 3 ) and stirred for 16 hr. The white precipitate was filtered and washed with distilled water to remove the liberated z ' sopropanol. The product could be maintained moist, or dried at 100°C. XRD of dried material showed no identifiable lines in the diffractogram, suggesting the product was amorphous.
  • Example 3 Preparation of Titanium Complex 1.
  • Titanium tetraz ' sopropoxide (35.5g, 0. 125 mol) was treated with excess water ( 100 cm 3 ) and stirred for 16 hr. The white precipitate was filtered and washed with distilled water to remove the liberated z ' sopropanol. The product was maintained moist, and added to excess triethanolamine, (80 cm 3 ) The reaction was slowly heated to 150°C under reduced pressure, during which time the excess water from the titania slurry was distilled off. The reaction was held at 150°C for around 6 hr, during which time the white titania reacted and the reaction turned a pale transparent yellowish colour. Excess triethanolamine was removed by vacuum distillation.
  • the complexes formed as described above can be subjected to further processing in the preparation of industrially-applicable products such as ceramics and films. Such further processing can involve any standard technique directed towards formation of the final product.
  • the titanium alkanolamine complexes described can be used as precursors for further processing.
  • exchange of the alkanolamine ligands can be achieved to form alternative complexes.
  • the titanium alkanolamine complexes can be hydrolysed under controlled conditions to form sols or gels for the purposes of forming titania materials or ceramics in the form of fibres, powders, films and coatings, monoliths or other morphologies as will be known from other means.
  • the complexes can also be combined with other components to form ceramic precursors for titanate ceramics used in electronic or other applications. Common examples will be barium titanate, strontium titanate, or other group 1 or 2 titanates, or mixtures thereof. Bismuth, lead, lead zirconate and other titanate compositions will also be accessible using the titanium alkanolamine complexes described.

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Abstract

The invention relates to a method for preparing an aluminium- or titanium-containing complex or complexes from an aluminium or titanium source respectively comprising reacting the aluminium or titanium source with a solvent consisting essentially of aminoalcohol(s). The products of the method may be used to prepared industrially-useful materials, such as ceramics.

Description

SYNTHESIS OF ALUMINIUM AND TITANIUM COMPOUNDS
TECHNICAL FIELD
The invention relates to a method of producing aluminium and titanium complexes. These complexes are convenient for use in further processing such as in preparing ceramics.
BACKGROUND ART
Titanium
The two major sources of titanium in nature are the minerals ilmenite, (FeTiOs) and rutile, (Ti02). Other sources also exist such as perovskite, (CaTiθ3), sphene, (CaTiSiOs), geikelite, (MgTi0 ), anatase, (Ti02) and brookite (Ti02). Other ion titanium oxide phases, eg pseudorutile, leucoxene, pseudobrookite and synthetic titanium containing slags are also important as raw materials.
The standard routes of processing ore are dependent of the Tiθ2 content. High grade ore (generally Ti02>85% normally rutile) is refined by chlorination in what is termed the chloride process. Lower grade ore is generally processed via the sulfate route. Low grade ore (50-60% Ti02 content) may also be transformed by partial reduction and acid leaching in a beneficiation process to produce synthetic rutile containing > 90% Ti02 which can then be used in the chloride process. The two main processing routes (i.e. the sulfate route and the chloride process) can be summarised as follows: (i) The Sulfate Route
Ilmenite or similar material with a high ion content is heated with hot sulfuric acid. Ferrous sulfate (copperas) is precipitated and filtered. The filtrate is concentrated and heated under conditions to precipitate controlled particle size anatase pulp, which can be washed, de-watered and fired to form synthetic anatase or rutile.
5H20 + FeTiOs + 2H2S04 ► FeS04.7H20 + TiOS04
TiOS04 + 2H20 ► "TiO(OH)2" + H2S04 Λ
"TiO(OH)2" ► Ti02
The major use for the titanium dioxide produced is in paints and pigments.
(ii) The Chloride Process
High grade ore is chlorinated in a fluidised bed reactor in the presence of coke at high temperature:
Ti02 + 2C + 2C12 ► 2CO + TiCl4
The chloride process is more compact than the sulfate route, the by-products are considerably less and a purer product can be obtained. However there are high temperature and corrosion problems and also toxicity hazards due to the use of large amounts of chlorine, the formation of titanium tetrachloride and to the waste products of the chlorination.
Production of Further Industrially Applicable Compounds
Use of the titanium compounds produced via the sulfate route and the chloride process to manufacture titanium based chemicals is generally carried out via standard processes. Ti02 is used as a white pigment and is generally made by hydrolysis of titanium sulfate or vapour-phase oxidation of TiCl with oxygen. High purity titanium based chemicals are usually prepared from TiCl4 that has been purified by repeated distillation. In particular, titanium alkoxides and other sol-gel precursors are prepared from TiCl .
TiC + 4ROH ► Ti(OR)4 + 4HC1
R is commonly isopropyl, n-propyl or n-butyl.
Precipitation of hydrated titanium hydroxide TiO(OH)o and its subsequent conversion to the double oxalate (NH )2[TiO(C20 )2], which can be reciystallised from methanol, has been shown to yield ultra-high purity Ti02 on calcination.
It has been reported that complexes of titanium can be prepared from rutile or anatase via a modified sulfate route using the chelating ligand catechol (ref J A Davies δδ S Dutremez J. Am. Ceram. Soc, 73 (1990), 1429). Calcination of the compound Ba(Ti(catecholate)3).3H20 yielded BaTi03 powder. The excellent chelating ability of catechol means that a relatively pure starting material must be used to prevent ion impurities being carried into the product. Similarly, sodium, potassium or barium titanates can be prepared from rutile or anatase via ethylene glycolate complexes (ref. G J Gainsford, C Lensink, N B Milestone and T Kemmitt. Inorg. Chem., 34 (1995), 746). The ethylene glycolate or catecholate complexes can be used to form ceramic powders. However, their limited solubilities do not allow them to be used as sol-gel reagents, which may be utilised in many useful applications. No examples have been reported where Tiθ2 can be used directly in a process to produce useful sol-gel reagents, except where TiCl4 is prepared as an intermediate compound. Aluminium
Aluminium alkoxides can be prepared from the chloride, AICI3 which is produced from the reaction of CI2 with aluminium metal, or directly from aluminium metal using a catalyst (HgCh). The industrial preparation of aluminium is via the highly energy intensive electrolytic method in molten cryolite at 800- 1000C.
A number of methods have been used to prepare alumatrane, and several studies have been carried out to investigate its oligomeric behaviour, summarised in a recent paper by Pinkas and Verkade Inorg Chem 1993, Z2_, 271 1. One recent preparative method involves preparing alumatrane directly from Al(OH)3 and triethanolamine in ethylene glycol (Laine, R.M. Laine (Ed.) Applications of Organometallic Chemistry in the Preparation and Processing of Advanced Materials, Kluwer, Dordrecht ( 1995), p69). However, that process suffers from the disadvantages of not allowing straightforward recycling of excess reagents and that use of ethylene glycol limits the reaction temperature, particularly if the reaction is carried out under reduced pressure.
Thus it is an object of the invention to provide an alternative method for the production of aluminium- and titanium- containing complexes in forms convenient for further processing which allows minimisation of the disadvantages of the prior art.
It has now been surprisingly found that it is possible to convert an aluminium source to produce aluminium-containing complexes suitable for further processing without using a glycol based solvent but instead employing a solvent consisting of aminoalcohol(s). It has been further found that it is equally possible to produce titanium-containing complexes from titanium sources using aminoalcohol solvents. It is broadly upon these surprising findings that the present invention is based.
SUMMARY OF THE INVENTION
In broad terms the invention in a first aspect comprises a method for preparing an aluminium containing complex or complexes from an aluminium source by reacting said source with a solvent consisting essentially of aminoalcohol(s) .
Preferably the solvent consists essentially of triethanolamine, diethanolamine, or N- methyldiethanolamine, or mixtures of these.
Preferably the aluminium source is bauxite, boehmite or pseudo-boehmite.
Preferably the complex(es) formed are alumatrane complex(es)
In broad terms the invention in a second aspect comprises a method for preparing a titanium containing complex or complexes from a titanium source by reacting said source with a solvent consisting essentially of aminoalcohol(s) .
Preferably, said titanium source is amorphous.
More preferably, the titanium source is amorphous titanium oxyhydroxide.
Conveniently, the method includes, as a preliminary step, the preparation of amorphous titaniu oxyhydroxide.
This preliminary preparative step will preferably involve base-precipitation from a titanium salt or complex solution, conveniently aqueous titanyl sulphate. Most preferably, the base employed will be ammonia, which will be added in excess. Alternatively, the preliminary preparative step will involve hydrolysis of a hydrolysable titanium source such as a titanium salt, titanium complex or titanium alkoxide.
Preferably, once obtained the amorphous titanium oxyhydride starting material is washed, conveniently with distilled water, and retained moist as a wet slurry.
Alternatively, once obtained the amorphous titanium oxyhydride is dried, for example at 100°C.
Preferably the solvent consists essentially of triethanolamine, diethanolamine or N-methyldiethanolamine, or mixtures of these.
Preferably the complex(es) formed are titanatrane complex(es).
A base catalyst can be present in the reaction mix. This can be an alkali metal base catalyst or an alkaline earth base catalyst.
Preferably the alkali metal base catalyst is present and more preferably is selected from the Li, Na, K, or Cs oxides or hydroxides.
Preferably the reaction is carried out at a temperature of between about 100°C and 260°C (inclusive).
Preferably the reaction time is between 5 minutes and 48 hours, more preferably 2- 24 hours.
Conveniently, the reaction is effected under subatmospheric pressure, preferably at a pressure between 5 and 750 torr, most preferably at a pressure between 10 and 50 torr. Alternatively, the reaction is effected at atmospheric pressure in the presence of an inert gas.
The invention also provides aluminium- and titanium-containing complexes obtained by the methods described above.
DESCRIPTION
As defined above, the process of the invention converts an aluminium or titanium source into convenient forms of aluminium- or titanium- containing complexes for further processing. This is achieved through the reaction of the source material (such as boehmite, bauxite, or rutile) with a solvent which does not include glycols but which instead consists of aminoalcohol(s).
By "aminoalcohor as used herein, is meant a compound of formula (I):
Figure imgf000009_0001
N ^~~ R2 OH (I) X
wherein Ri and R2 are independently selected from C2-C3 alkylene groups and X is selected from hydrogen, alkyl and R3OH wherein R3 is a C2-C3 alkylene group.
Examples include triethanolamine, diethanolamine and N-alkyl diethanolamines for example N-methyldiethanolamine, with triethanolamine, diethanolamine and N- methyldiethanolamine being preferred. The aminoalcohol solvent which is currently most preferred is triethanolamine. The solvent can comprise one aminoalcohol only, or a mixture of two or more aminoalcohols. Aminoalcohol solvents suitable for use in the invention are readily available from commercial sources.
A base catalyst can be employed to decrease the reaction time. While not critical to the process, use of such a catalyst is therefore indicated where it is necessary or desirable to quickly produce the aluminium- or titanium-containing complex.
When employed, the base catalyst used in the reaction may be an alkali metal or alkaline earth hydroxide or oxide, with lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, barium hydroxide or calcium hydroxide being preferred. Again, these are readily available from commercial sources.
The basic reaction for the preparation of alumatranes from an aluminium source can be represented by:
Al(OH)3 + TEAHs ► [Al(OCH CH2)3N]4
where TEAH3 = triethanolamine, as a representative, although preferred, aminoalcohol.
The basic reaction, using TiO(OH)2.nH2θ and triethanolamine (again as the representative, although preferred, aminoalcohol), is
TiO(OH)2.nH20 + TEAH3 ► Tix(TEA)y (x= l-3, y=x+ l)
Representative formulae of the products where x is 1, 2 or 3 can be depicted as follows:
Figure imgf000011_0001
Figure imgf000011_0002
Figure imgf000011_0003
At atmospheric pressure, the reagents (including the catalyst, if desired) are preferably mixed in a distillation setup which is thoroughly flushed with an inert gas; usually argon or nitrogen, although other gases as will be known in the art may be used. The mixture is heated and allowed to react, with the water being removed continuously. The reaction is preferably run with an excess of the aminoalcohol solvent which, as indicated above, is usually triethanolamine.
Preferably the reaction is conducted at or near the boiling point of the aminoalcohol (or, where a mixture of aminoalcohols is used, at or near the boiling point of the mixture). Therefore, when triethanolamine is used, the upper limit of the temperature range will be approximately 260°C. Preferably the temperature range will be between 100°C and 260°C and more preferably between 200°C and 250°C.
The pressure at which the reaction is carried out can also be varied. While the reaction proceeds satisfactorily at atmospheric pressure (desirably in the presence of an inert gas as described above), it is also effective at subatmospheric pressures (less than 760 torr, including at pressures which are significantly subatmospheric). Conveniently, the pressure can be between 5 and 750 torr. More conveniently, the pressure will be between 10 and 50 torr.
Carrying out the reaction under reduced pressure has a number of advantages, including that it facilitates removal of water produced in the reaction and allows lowering the temperature of the reaction. Under reduced pressure, preferably the reaction temperature is between 100 and 260°C, and more preferably between 100 and 160°C.
While the process of the invention can proceed as outlined above, it is preferred that it commence with the starting aluminium or titanium source in a particular form. This is especially true for the titanium source, which is preferably amorphous, and more preferably in the form of amorphous titanium oxyhydroxide. Amorphous titanium oxyhydroxide can contain a range of TiO bonds including, but not limited to Ti=0, Ti-OH, Ti-O-Ti, Ti-OH→Ti and H20→Ti. The material is amorphous, thus exhibiting no lines in an X-ray diffraction (XRD) diffractogram.
The amorphous titanium oxyhydroxide starting material can be prepared by a number of processes. For example, the starting material can be prepared by hydrolysis of a hydrolysable titanium source. This can occur at acid, base or neutral pH and involve hydrolysis of, for example, a titanium salt, titanium complex or titanium alkoxide.
It is however preferred that the amorphous titanium oxyhydroxide starting material be prepared by base precipitation, for example from a titanium salt or complex solution. Conveniently, the base used will be ammonia although this is by no means to be interpreted as anything other than illustrative.
Titania gels, powders, sols or other particulate precipitates can be prepared for application as a starting material for the process. Exemplary reaction schemes are as follows:
TiO.S0 + xH20 + 2NH OH → TiO(OH)2.nH20 + (NH4)2S04
TiCl4 + xH20 + 4NH4OH → TiO(OH)2.nH20 + 4NH4C1
Ti(OR)4 + xH20 → TiO(OH)2.nH20 + 4ROH.
Once obtained, the amorphous titanium oxyhydroxide hydrate is washed thoroughly, preferably with distilled water to remove any soluble impurities. Presence of sulphate, chloride or other ions in the washings can be detected by standard analytical methods as will be known in the art as desired. For use as a starting material for further processing, the product can be dried (conveniently at 100°C). It is however more preferred that the starting material be retained as a wet slurry. The applicants have found that as a moist or wet slurry, the amorphous titanium oxyhydroxide exhibits much greater reactivity in further reaction steps. This is therefore viewed as highly desirable, although by no means essential.
The process to which the present invention is directed makes the reaction simpler than prior art processes, allowing for more straightforward recycling of excess reagents, and allows the reaction to be carried out at higher temperature, increasing the reaction rate. The addition of the optional catalyst further increases the reaction rate by increasing the basicity of the reaction mixture.
EXPERIMENTAL
While the present invention is broadly as described above, a better understanding will be gained from the experimental section which follows. This includes a number of examples to further illustrate practice of the invention. It will however be appreciated that the examples are non-limiting.
Example 1
Pseudo-boehmite, A10(OH).H20, 5.0 g, was placed in a 250 cm3 round bottomed flask containing triethanolamine, 80 cm3. The flask was attached to a distillation apparatus and the pressure reduced to around 12 torr. The reaction was gradually heated with vigorous stirring, so that the reactants eventually reached 230 °C. The reaction was maintained at this temperature for around 8 hr. The excess triethanolamine was distilled off in vacuo, leaving a cloudy, yellowish thick syrup, which solidified on cooling. The product was dissolved in methanol, 100 cm3, and filtered to remove any traces of undissolved solids. The methanol was removed by distillation and the product evacuated at 100 °C to remove all of the methanol. Yield 40 g.
The yield includes polymerised triethanolamine together with the aluminate complex. The complex is soluble in many organic solvents, and does not precipitate alumina on addition of water, which makes it an ideal ceramic or sol-gel precursor, or component thereof, having excellent storage and handling characteristics.
Example 2: Preparation of Amorphous Titanium Oxyhydroxide.
This preferred starting materical can be prepared by either of the following approaches.
1. Aqueous titanyl sulphate (2.5 1 of a 0.18 M solution), was neutralised with aqueous ammonia (33%). Excess ammonia was added to maintain pH = 9. After cooling to room temperature, the white precipitate was filtered and washed several times with distilled water, to ensure the removal of all the ammonium sulphate byproduct. The product could be maintained moist, or dried at 100°C. XRD of dried material showed no identifiable lines in the diffractogram, suggesting the product was amorphous. Samples from different batches were dried at 100°C.
2. Titanium tetratsopropoxide (28.4g, 0. 1 mol) was treated with excess water (100 cm3) and stirred for 16 hr. The white precipitate was filtered and washed with distilled water to remove the liberated z'sopropanol. The product could be maintained moist, or dried at 100°C. XRD of dried material showed no identifiable lines in the diffractogram, suggesting the product was amorphous. Example 3: Preparation of Titanium Complex 1.
Hydrous, amorphous titania slurry, (equivalent to around 10 g dry weight Ti02, 0. 125 mol), was added to excess triethanolamine, (80 cm3) The reaction was slowly heated to 150°C under reduced pressure, during which time the excess water from the titania slurry was distilled off. The reaction was held at 150°C for around 6 hr, during which time the white titania reacted and the reaction turned a pale transparent yellowish colour. Excess triethanolamine was removed by vacuum distillation. The product cooled as a transparent, straw-coloured glassy solid, Yield 35 g corresponding to a Ti:TEA ratio of around 1 : 1.6. Proton and 13C NMR studies showed that the product contained triethanolamine in a range of environments consistent with the mixture of titanium triethanolamine species present.
Example 4: Preparation of Titanium Complex 2.
Hydrous, amorphous titania slurry, (equivalent to around 10 g dry weight Ti02, 0. 125 mol), was added to triethanolamine, (37.3 g, 0.25 mol) The reaction was slowly heated to 150°C under reduced pressure, during which time the excess water from the titania slurry was distilled off. The reaction was held at 150°C for around 6 hr, during which time the white titania reacted and the reaction turned a pale transparent yellowish colour. Excess triethanolamine was removed by vacuum distillation. The product cooled as a transparent, straw-coloured, extremely viscous syrup. Yield 44 g corresponding to a Ti:TEA ratio of around 1 : 2. Proton and 13C NMR studies showed that the product contained triethanolamine in a range of environments consistent with the mixture of titanium triethanolamine species present. Example 5: Preparation of Titanium Complex 3.
Hydrous, amorphous titania slurry, (equivalent to around 2 g dry weight Ti02, 0.025 mol), was added to excess diethanolamine, (80 cm3) The reaction was slowly heated to 120°C under reduced pressure, during which time the excess water from the titania slurry was distilled off. The reaction was held at 120°C for around 6 hr, during which time the white titania reacted and the reaction turned a pale transparent yellowish colour. Excess diethanolamine was removed by vacuum distillation. The product cooled as a transparent, straw-coloured glassy solid, yield 6.5 g.
Example 6: Preparation of Titanium Complex 4.
Titanium tetraz'sopropoxide (35.5g, 0. 125 mol) was treated with excess water ( 100 cm3) and stirred for 16 hr. The white precipitate was filtered and washed with distilled water to remove the liberated z'sopropanol. The product was maintained moist, and added to excess triethanolamine, (80 cm3) The reaction was slowly heated to 150°C under reduced pressure, during which time the excess water from the titania slurry was distilled off. The reaction was held at 150°C for around 6 hr, during which time the white titania reacted and the reaction turned a pale transparent yellowish colour. Excess triethanolamine was removed by vacuum distillation. The product cooled as a transparent, straw-coloured glassy solid, Yield 34.6 g, corresponding to a Ti:TEA ratio of around 1 : 1.6. Proton and 13C NMR studies showed that the product contained triethanolamine in a range of environments consistent with the mixture of titanium triethanolamine species present. Example 7: Preparation of Titanium Complex 5
Hydrous, amorphous titania slurry, (equivalent to around 2 g dry weight Ti0 , 0.025 mol), was added to excess N-methyldiethanolamine, (80 cm3). The reaction was slowly heated to 120°C under reduced pressure, during which time the excess water from the titania slurry was distilled off. The reaction was held at 120°C for around 6 hours, during which time the white titania reacted and the reaction turned a pale transparent yellowish color. Excess N-methyldiethanolamine was removed by vacuum distillation. The product cooled as a transparent, straw-colored glassy solid which slowly crystallised over the next 48 hr at room temperature. A sample of the product was reciystallised from a dichloromethane/diethylether mixture to yield white chunky crystals. NMR, 1H: 2.55 (s), NCH3; 2.97(m) NCH2; 4.39 ppm (t) (5.5 Hz) OCH2. i3C:43.38, NCH3; 58.95, NCH2; 70.07 ppm, OCH2.
INDUSTRIAL APPLICABILITY
The complexes formed as described above can be subjected to further processing in the preparation of industrially-applicable products such as ceramics and films. Such further processing can involve any standard technique directed towards formation of the final product.
In particular, the titanium alkanolamine complexes described can be used as precursors for further processing. For example, exchange of the alkanolamine ligands can be achieved to form alternative complexes. The titanium alkanolamine complexes can be hydrolysed under controlled conditions to form sols or gels for the purposes of forming titania materials or ceramics in the form of fibres, powders, films and coatings, monoliths or other morphologies as will be known from other means. The complexes can also be combined with other components to form ceramic precursors for titanate ceramics used in electronic or other applications. Common examples will be barium titanate, strontium titanate, or other group 1 or 2 titanates, or mixtures thereof. Bismuth, lead, lead zirconate and other titanate compositions will also be accessible using the titanium alkanolamine complexes described.
The foregoing describes the invention including preferred forms thereof. Alterations and modifications as will be apparent to those skilled in the art are intended to be included within the scope of the invention which is limited only by the appended claims.

Claims

1. A method for preparing an aluminium- or titanium- containing complex or complexes from an aluminium or titanium source respectively comprising reacting the aluminium or titanium source with a solvent consisting essentially of aminoalcohol(s).
2. A method as claimed in claim 1 wherein the reaction takes place in the presence of an alkali metal or alkaline earth base catalyst.
3. A method as claimed in claim 1 wherein an aluminium source is reacted to form an aluminium containing complex.
4. A method as claimed in claim 3 wherein the aluminium source is bauxite, boehmite or pseudo-boehmite.
5. A method as claimed in claim 3 wherein the solvent consists essentially of triethanolamine or diethanolamine or mixtures thereof.
6. A method as claimed in claim 5 wherein the solvent is triethanolamine.
7. A method as claimed in claim 6 wherein the complex formed is alumatrane.
8. A method of claim 1 wherein a titanium source is reacted to form an titanium containing complex.
9. A method of claim 7 wherein the titanium source is rutile or anatase.
10. A method as claimed in claim 8 wherein the solvent consists essentially of triethanolamine or diethanolamine or mixtures thereof.
1 1. A method as claimed in claim 10 wherein the solvent is triethanolamine.
12. A method as claimed in claim 8 wherein the titanium source is amorphous.
13. A method as claimed in claim 12 wherein the amorphous titanium source is amorphous titanium oxyhydroxide.
14. A method as claimed in claim 13 which includes, as a preliminary step, the preparation of amorphous titanium oxyhydroxide.
15. A method as claimed in claim 14 wherein said preliminary step involves base precipitation of said amorphous titanium oxyhydroxide.
16. A method as claimed in claim 15 wherein said amorphous titanium oxyhydroxide is base precipitated from aqueous titanyl sulphide.
17. A method as claimed in claim 16 wherein said base is ammonia.
18. A method as claimed in claim 17 wherein said ammonia is added in excess.
19. A method as claimed in claim 13 in which said amorphous titanium oxyhydroxide is washed prior to reaction with said aminoalcohol solvent.
20. A method as claimed in claim 19 wherein said washed amorphous titanium oxyhydroxide is retained in moist form as a wet slurry for reaction with said aminoalcohol solvent.
21. A method as claimed in claim 19 wherein said washed amorphous titanium oxyhydroxide is dried prior to reaction with said aminoalcohol solvent.
22. A method as claimed in claim 10 wherein the complex formed is titanatrane.
23. A method as claimed in claim 1 wherein the reaction is carried out at reduced pressure.
24. A method as claimed in claim 23 wherein said reduced pressure is between 5 and 750 torr.
25. A method as claimed in claim 23 wherein said reduced pressure is between
10 and 50 torr.
26. A method as claimed in claim 1 wherein the reaction is carried out under an inert gas.
27. A method as claimed in claim 26 wherein the inert gas is argon.
28. A method as claimed in claim 26 wherein the inert gas is nitrogen.
29. A method as claimed in claim 1 wherein said aluminium or titanium source is reacted with said aminoalcohol solvent for between 5 minutes and 48 hours.
30. A method as claimed in claim 1 wherein said aluminium or titanium source is reacted with said aminoalcohol solvent for between 2 hours and 24 hours.
31. An aluminium-containing complex prepared by the method as claimed in any one of claims 1 to 7 and 23 to 30.
32. A titanium-containing complex prepared by the method as claimed in any one of claims 1, 2 and 8 to 30.
33. An aluminium- containing complex obtainable by a method as claimed in any one of claims 1 to 7 and 23 to 30.
34. A titanium-containing complex obtainable by a method as claimed in any one of claims 1, 2 and 8 to 30.
PCT/NZ1997/000169 1996-12-16 1997-12-16 Synthesis of aluminium and titanium compounds WO1998027010A1 (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0884320A2 (en) * 1997-06-13 1998-12-16 Industrial Research Limited Titanium amino alcohol complex, method for manufacturing the same, titanium dioxide solution of the complex, titanium oxide film, titanium oxide powder, and method for manufacturing the titanium oxide film
JP2006076943A (en) * 2004-09-10 2006-03-23 Nissan Chem Ind Ltd Manufacturing method of alkanolamine compound of metal
WO2008082384A1 (en) * 2006-12-28 2008-07-10 E. I. Du Pont De Nemours And Company Processes for producing titanium dioxide
US8137647B2 (en) 2006-12-28 2012-03-20 E. I. Du Pont De Nemours And Company Processes for producing titanium dioxide

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0356132A1 (en) * 1988-08-19 1990-02-28 Solex Research Corporation of Japan A method for manufacturing titanium oxide
EP0565064A1 (en) * 1992-04-10 1993-10-13 Murata Manufacturing Co., Ltd. Method for film formation of barium titanate
EP0607967A1 (en) * 1993-01-20 1994-07-27 Murata Manufacturing Co., Ltd. Production of thin films of a lead titanate system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0356132A1 (en) * 1988-08-19 1990-02-28 Solex Research Corporation of Japan A method for manufacturing titanium oxide
EP0565064A1 (en) * 1992-04-10 1993-10-13 Murata Manufacturing Co., Ltd. Method for film formation of barium titanate
EP0607967A1 (en) * 1993-01-20 1994-07-27 Murata Manufacturing Co., Ltd. Production of thin films of a lead titanate system

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
DERWENT ABSTRACT, Accession No. 69188c/39, Class E32, G01; & SU,A,715 476 (DOBROVOLSKIIP) 15 February 1980. *
DERWENT ABSTRACT, Accession No. 87-067647/10, Class E16 (E37); & JP,A,62 019 558 (MITSUITOATSU CHEM INC) 28-01-87. *
DERWENT ABSTRACT, Accession No. 88-366164/51, Class E12, B02, L02; & JP,A,63 277 687 (HAKUSUI KAGAKJKOGY) 8 May 1987. *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0884320A2 (en) * 1997-06-13 1998-12-16 Industrial Research Limited Titanium amino alcohol complex, method for manufacturing the same, titanium dioxide solution of the complex, titanium oxide film, titanium oxide powder, and method for manufacturing the titanium oxide film
EP0884320A3 (en) * 1997-06-13 2000-11-02 Industrial Research Limited Titanium amino alcohol complex, method for manufacturing the same, titanium dioxide solution of the complex, titanium oxide film, titanium oxide powder, and method for manufacturing the titanium oxide film
JP2006076943A (en) * 2004-09-10 2006-03-23 Nissan Chem Ind Ltd Manufacturing method of alkanolamine compound of metal
JP4656292B2 (en) * 2004-09-10 2011-03-23 日産化学工業株式会社 Method for producing metal alkanolamine compounds
WO2008082384A1 (en) * 2006-12-28 2008-07-10 E. I. Du Pont De Nemours And Company Processes for producing titanium dioxide
US8137647B2 (en) 2006-12-28 2012-03-20 E. I. Du Pont De Nemours And Company Processes for producing titanium dioxide
AU2006352486B2 (en) * 2006-12-28 2012-12-20 E. I. Du Pont De Nemours And Company Processes for producing titanium dioxide

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