Sodium titanate preparation

The overall yield is essentially 100 by any of the preparation methods, but the physical characteristics of the ion exchangers are dependent on preparation conditions. For example, sodium titanate prepared by Eqs. la and lb with hydrolysis in one liter of water per mole of Ti(OC3H7)4 has a bulk density of 0.U5 g/cm3 and a specific surface area of lO-UO m /g. The same material prepared by Eqs. la and lb and hydrolyzed in a solution of 100 ml of water in 1000 ml of acetone for each mole of Ti(OC2H7)4 has a bulk density of 0.35 g/cm3 and a specific surface area of 200-UOO m /g. In all cases, the materials consist of agglomerates of 50-100 A particles with the degree of aggregation of the particles determining both the bulk density and surface area. 

Anatase and mtile are produced commercially, whereas brookite has been produced by heating amorphous titanium dioxide, which is prepared from an alkyl titanate or sodium titanate [12034-34-3] with sodium or potassium hydroxide in. an autoclave at 200—600°C for several days. Only mtile has been synthesized from melts in the form of large single crystals. More recentiy (57), a new polymorph of titanium dioxide, Ti02(B), has been demonstrated, which is formed by hydrolysis of K Ti O to form 20, followed by subsequent calcination/dehydration at 500°C. The relatively open stmcture... 

A program to characterize the sodium titanate material has verified that the chemical and physical properties are reproducible from batch to batch for any of the preparation methods. 

More efficient use of the titanate material was achieved by passing the column effluent through a synthetic zeolite bed (Zeolon 900 Na from the Norton Co., Akron, Ohio) to sorb Cs which "leaked" from the column. A zeolite bed equal to 20% by weight of the titanate was sufficient to produce a Cs DF>10° in the effluent from a titanate column loaded to slightly more than 100% of the calculated capacity. The use of the zeolite does not effect the overall process conditions since it can be incorporated directly into the sodium titanate during preparation. A Dowex 1-X8 resin bed was used to remove the from the effluent and also served... 

Wide variations in Cs and Na leaching observed in some of the first samples produced were found to result from the formation of the corresponding molybdate compounds which are highly water soluble. This problem was eliminated by the addition of 1-2% by weight of elemental silicon which served as a reducing agent and prevented molybdate formation. The silicon was added during the preparation of the sodium titanate material. 

The preparation, composition, structure and leaching characteristics of a crystalline, ceramic radioactive waste form have been discussed, and where applicable, compared with vitrified waste forms. The inorganic ion exchange materials used such as sodium titanate were prepared from the corresponding metal alkoxide. The alkoxides were reacted in methanol with a base containing the desired exchangeable cation and the final powder form was produced by hydrolysis in an acetone-water mixture followed by vacuum drying the precipitate at ambient temperature. 

The baseline process, including the pressure sintering step, was demonstrated with both simulated high level waste and under hot cell conditions using a waste solution prepared from typical spent light water reactor fuel. A batch contacting method using sodium titanate was also evaluated, but the overall decontamination factor was much lower than obtained in the column process. 

Nuclei are produced by converting the purified titanium oxide hydrate to sodium titanate, which is washed free of sulfate and then treated with hydrochloric acid to produce the rutile nuclei. Rutile nuclei can also be prepared by precipitation from titanium tetrachloride solutions with sodium hydroxide solution. 

Hydrous metal oxide powders, such as sodium titanate, NaT O, can be prepared by treating TYZOR TPT with sodium hydroxide in methanol solvent to form a soluble intermediate, which is hydrolyzed in acetone—water to form an ion-exchange material useful in treating radioactive waste (158). Exchange of the sodium ion with an active metal such as Ni, Pt, or Pd gives heterogeneous catalysts useful in olefin polymerization, coal liquification, and hydrotreating. 

This paper describes some of our initial studies of the solution properties of sodium titanate powders in order to understand and control the metal-loading process in the preparation of a heterogeneous catalyst from the materials. The purposes of this study are 1) to define the pH and concentration regimes in which nickel is loaded onto sodium titanate as monomeric ions via ion exchange, as polymeric clusters via hydrolysis, or as discrete particles of colloidal nickel hydroxide, and 2) to characterize the catalysts with respect to the dispersion of the active metal under reaction conditions by measuring the activity and selectivity of the catalysts for a known "structure-sensitive" reaction, the hydrogenolysis of n-butane. 

Hydrous sodium titanate was prepared by the method of Dosch and Stephens (1). Titanium isopropoxide was slowly added to a 15 wt% solution of sodium hydroxide in methanol. The resulting solution was hydrolyzed by addition to 10 vol% water in acetone. The hydrolysis product is an amorphous hydrous oxide with a Na Ti ratio of 0.5 which contains, after vacuum drying at room temperature, approximately 13.5 wt% water and 2.5 wt% residual alcohol. The ion-exchange characteristics of the sodium titanate and the hydrolysis behavior of the nickel nitrate solutions were characterized using a combination of potentiometric titrations, inductively coupled plasma atomic emission (ICP) analysis of filtrates, and surface charge measurements obtained using a Matec electrosonic amplitude device. 

Three different nickel-loaded sodium titanates were prepared by exposing 5 gm of the sodium titanate powder to aqueous solutions of nickel nitrate containing sufficient nickel to incorporate one mole of nickel for every two moles of sodium on the support (corresponding to the stoichiometry associated with complete ion exchange). Each sample was prepared using different pH conditions (and thus, different Ni(II) concentrations) to vary the mechanism of... 

Sodium Titanate, Niobate, and Zirconate. Preparation and properties of the inorganic cation exchangers Na(Ti205H), NaClft OgH), and Na(Zr205H) have been intensively studied by R. G. Dosch and his colleagues at Sandia Laboratories. (h95.)... 

These ion exchange materials are synthesized via the hydrolytic reaction of NaOH and water with the metal alkoxides Ti(0C3H7)it, Nb(0C2H5)5, and ZrCOC Hg) as illustrated for preparation of sodium titanate (Eqn l). 

Inclusion of these cations does impart new catalytic activities, but in many cases the active site results from a metal ion that has left the framework and entered the pore space upon heating, especially in the presence of water vapour. This is thought to be the case for zinc- and gallium-containing solids used in the dehydrocyclisation of butane and propane to aromatics in the Cyclar process (Chapter 9). Boron, iron, chromium and vanadium all appear to leave the framework under harsh conditions. The incorporation of titanium and more recently tin into framework sites within silicates have become very important substitutions, because both titanosilicates and stannosilicates have been shown to contain stable Lewis acid sites of importance in selective oxidation catalysis. The metal atom can coordinate additional water molecules in the as-prepared material, but these can be removed by heating. In the synthesis of titanosilicates, titanium is usually added to the gel as the alkoxide, and synthesis performed in the absence of sodium hydroxide to avoid precipitation of sodium titanate or nanoparticulate titanium oxides. 

Pookmanee, P., Rujijanagul, G., Ananta, S Heimann, R.B., and Phanichphant, S. (2004) Effect of sintering temperature on microstructure of hydrothermally prepared bismuth sodium titanate ceramics. J. Eur. Ceram. Soc., 24, 517-520. 

J. Lehto, Sodium Titanate for Solidification of Radioactive Wastes- Preparation, Structure aiul Ion Exchaiige Properties, Academic Dissertation, Report Series in Radio chemistry, (5/1987), University of Helsinki, Firdand. 

Dialkylaminoethyl acryhc esters are readily prepared by transesterification of the corresponding dialkylaminoethanol (102,103). Catalysts include strong acids and tetraalkyl titanates for higher alkyl esters and titanates, sodium phenoxides, magnesium alkoxides, and dialkyitin oxides, as well as titanium and zirconium chelates, for the preparation of functional esters. Because of loss of catalyst activity during the reaction, incremental or continuous additions may be required to maintain an adequate reaction rate. 

Fluoroall l-SubstitutedTitanates. Tetraliexafluoroisopropyl titanate [21416-30-8] can be prepared by the reaction of TiCl and hexafluoroisopropyl alcohol [920-66-17, in a process similar to that used for TYZOR TPT (7). Alternatively, it can be prepared by the reaction of sodium hexafluoroisopropoxide and TiCl ia excess hexafluoroisopropyl alcohol (8). The fluoroalkyl material is much more volatile than its hydrocarbon counterpart, TYZOR TPT, and is used to deposit titanium on surfaces by chemical vapor-phase deposition (CVD). 

Dicarboxyhc acids, eg, succinic or adipic, do not dissolve titanic acid. A phthalate has been prepared by adding acidic titanium sulfate solution to sodium phthalate solution. 

Titanium was discovered in 1790 by Engfish chemist William Gregor. Five years later in 1795, Klaproth confirmed Gregor s findings from his independent investigation and named the element titanium after the Latin name Titans, the mythical first sons of the Earth. The metal was prepared in impure form first by Nilson and Pettersson in 1887. Hunter, in 1910, prepared the metal in pure form by reducing titanium tetrachloride with sodium. 

Compared with 49, 2,5-dioxabicyclo[2.2.2]octan-3-one (54) prepared from sodium 3,4-dihydro-2//-pyran-2-carboxylate has a much low polymerization reactivity [54] Lewis acids such as antimony pentachloride, phosphorus pentafluoride, and boron trifluoride etherate were not effective at all to initiate the polymerization of 54. Trifluoromethanesulfonic acid induced the polymerization of 54, but the yield and molecular weight of the polymer were low. Bicyclic lactone 54 was allowed to polymerize with anionic and coordination initiators such as butyl-lithium, lithiumbenzophenone ketyl, and tetraisopropyl titanate. However, the... 

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