Zirconate salts

Uhen Na was available at 60X of stoichiometry, a second zirconate salt, NayZrgFj, formed. The NayZrgF3 salt is believed to hydrate, forming a wetter cake that may liberate freestanding liquid when the cake is placed in a drum. Using 90X or greater stoichiometry of Na will produce a drier eake that does not contain free water. 

Ziegler-Natta catalysis, 358 Zirconates, bromo-, 430 Zirconates, chloro-, 430 Zirconates, fluoro-, 423 alkali metal salts, 425 alkylammonium salts, 427 divalent metal salts, 427 guanidinium salts, 427 hydrazinium salts, 427 vibrational spectra, 429 Zirconates, iodo-, 430 Zirconate salts... 

In France, Compagnie Europnene du Zirconium (CEZUS) now owned jointly by Pechiney, Eramatome, and Cogema, uses a separation (14) based on the extractive distillation of zirconium—hafnium tetrachlorides in a molten potassium chloride—aluminum trichloride solvent at atmospheric pressure at 350°C. Eor feed, the impure zirconium—hafnium tetrachlorides from the zircon chlorination are first purified by sublimation. The purified tetrachlorides are again sublimed to vapor feed the distillation column containing the solvent salt. Hafnium tetrachloride is recovered in an enriched overhead fraction which is accumulated and reprocessed to pure hafnium tetrachloride. 

Since discovering and making use of the piezoelectric effect in naturally occurring crystals such as quartz and Rochelle salts, scientists have produced a wide range of piezoelectric materials in the laboratoi y. An early example is barium titanate, used in an electrical component called a capacitor. Currently, most piezoelectric materials are oxide materials based on lead oxide, zirconate oxide, and titanium. These very hard piezoelectric materials are termed piezoceramics. 

A pure transition metal is best described by the band theory of solids, as introduced in Chapter 10. In this model, the valence s and d electrons form extended bands of orbitals that are delocalized over the entire network of metal atoms. These valence electrons are easily removed, so most elements In the d block react readily to form compounds oxides such as Fc2 O3, sulfides such as ZnS, and mineral salts such as zircon, ZrSi O4. ... 

Various new phosphonium salts were prepared in a one-pot reaction of carbon disulfide, phosphines, and 1 followed by an exchange reaction of the zirconated metal fragment with 2 equiv. of electrophiles (Scheme 8-23) [206],... 

Titanium is the most abundant metal in the earth crust, and is present in excess of 0.62%. It can be found as dioxy titanium and the salts of titanium acids. Titanium is capable of forming complex anions representing simple titanites. It can also be found in association with niobium, silicates, zircon and other minerals. A total of 70 titanium minerals are known, as mixtures with other minerals and also impurities. Only a few of these minerals are of any economic importance. 

Carbocations, 12 161—162, 163 from alkanes, 12 187 Carbocation salts, stable, 14 269 Carbochlorination, zircon, 13 82 Carbocyclic azo dyes, 9 245, 251 Carbodiimide (CDI) method, for covalent ligand immobilization, 6 396t Carbohydrate chemistry, microwaves in, 16 547-548... 

The diethylammonium salt of the tris(tetraphenyldisiloxanediolato)zirconate(IV) anion (33) has been obtained in very low yield from the reaction of [Zr(NEt2)4] with diphenylsilanediol in THF. The ligand results, under the basic reaction conditions, from condensation of two Ph2Si(OH)2 molecules. Anion (33) has an octahedral tris-chelate structure with a twist angle (46.9°) that indicates some distortion towards trigonal prismatic geometry.466... 

Salts of these elements, on treatment with soda, yield no precipitate, for they are dissolved by the alkali the compounds formed are indefinite, but it may be supposed that they contain aurate, MAuOg.Aq, or platinate, titanate, zirconate, or thorate, MPtOg.Aq, c. Iron and calcium titanates occur native FeTiOg is termed ilmenite, and CaTiOg perowskite. The first is isomorphous with and crystallises along with native ferric oxide the ore is known as titanic iron ore. It is the commonest compound of titanium. 

Our own studies with lithium zirconate have demonstrated the critical importance of the ratio between the lithium salts and zirconia used in its preparation [21]. Further, it appears that the reaction is strongly inhibited by the superficial formation of solid products curtailing capacity and impairing kinetics to the point where characteristic adsorption times are measured in hours rather than the seconds necessary. Very slow rates of CO2 adsorption can also be observed in the early published data on lithium zirconate and, while some progress has been made [39], developing a... 

There are certain crystals in which dipoles are spontaneously aligned in a particular direction, even in the absence of electric field. Such substances are called ferroelectric substances and the phenomenon is called ferroelectricty. The direction of polarisation in these substances can be changed by applying electric field. Baruion titanate (BaTi03), sodium potassium tartarate (Rochelle salt), and potassium hydrozen phosphate (KH2I04) are ferroelectric solids. If the alternate dipoles are in opposite directions, then the net dipole moment will be zero and the crystal is called anti-ferroelectric. Lead zirconate (PbZr03) is an anti-ferroelectric solid. 

SYNS HYACINTH SILICIC ACID, ZIRCONIUM(4+) SALT (1 1) ZIRCON... 

The first step is preparation of the solution. Aqueous solutions are prepared by dissolving either soluble salts in solvents (usually water) or metals in acids. For multicomponent systems, the mutual solubility of the various components must be considered. For example, a solution for lead zirconate cannot be prepared from lead nitrate and zirconium sulfate, both of which are soluble in water, because lead sulfate, which is insoluble, will precipitate. A solution of nitrates of both cations is satisfactory. 

An unusual precipitation uses a molten salt as solvent. For the preparation of lead zirconate titanate, Ti02, Zr02, and excess PbO are mixed with a NaCl-KCl mixture and reacted at 1000 C. Lead zirconate titanate is less soluble in the molten salts than is Ti02 or Zr02 and precipitates. Finally, the salt and excess PbO are leached out using an acetic acid solution. 

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