Salt solutions titanium

In halide salt solutions, titanium alloys exhibit somewhat lower but yet reasonably high pitting potentials. Vedues of +9 to +10.5 V (versus Ag/AgCl) can be expected in room-temperature... 

Salt Solutions. Titanium alloys are highly resistant to practically all salt solutions over the pH range of 3 to 11 and to temperatures well in excess of boiling. Titanium withstands exposure to solutions of chlorides (Ref44,45), bromides, iodides, sulfites, sulfates, borates, phosphates, cyanides, carbonates, bicarbonates, and anunonium compoimds. Corrosion rate values for titanium alloys in these various salt solutions are generally less than 0.03 mm/yr (1.2 mils/yr). 

In halide salt solutions, titanium alloys exhibit somewhat lower but yet reasonably high pitting potentials. Values of +9 to +10.5 V (verstis Ag(AgCl) can be expected in room-temperatiire chloride solutions, decreasing to approximately +1.2 V at 175 to 250 °C (345 to 480 °F). Pittii potentials of titanivun can be raised in chloride solutions by addition of sulfate ions (Ref 57). 

Seawater and salt solutions. Titanium alloys exhibit excellent resistance to most salt solutions over a wide range of pH and temperatures, (jood performance can be expected in sulfates, sulfites, borates, phosphates, cyanides, carbonates, and bicarbonates. Similar results can be expected with oxidizing anionic salts such as nitrates, molybdates, chromates, permanganates, and vanadates and also with oxidizing cationic salts including ferric, cupric, and nickel compounds. 

Some phosphides, such as titanium phosphide [12037-65-9] TiP, can be prepared bypassing phosphine over the metal or its haUde. Reaction of phosphine with heavy metal salt solutions often yields phosphines that may contain unsubstituted hydrogens. Phosphides may also be prepared by reducing phosphoms-containing salts with hydrogen, carbon, etc, at high temperatures, the main example of which is the by-product formation of ferrophosphoms in the electric furnace process for elemental phosphoms. Phosphoms-rich phosphides such as vanadium diphosphide [12037-77-3] may be converted to lower phosphides, eg, vanadium phosphide [12066-53-4] by thermal treatment. 

Greiss, J. C., Crevice Corrosion of Titanium in Aqueous Salt Solutions Corrosion, 24, 96 (1968)... 

A plant produces 100 kg/s of titanium dioxide pigment which must be 99 per cent pure when dried. The pigment is produced by precipitation and the material, as prepared, is contaminated with 1 kg of salt solution containing 0.55 kg of salt/kg of pigment. The material is washed countercurrently with water in a number of thickeners arranged in series. How many thickeners will be required if water is added at the rate of 200 kg/s and the solid discharged from each thickeners removes 0.5 kg of solvent/kg of pigment ... 

After that, titanium tetrachloride is slowly introduced. While it is introduced, the temperature in the reactor should not rise above 30 °C and the pressure should remain the same (when the temperature is above 30 °C and the pressure is above atmospheric, the supply of TiCLt should be slowed down or stopped altogether, and continued only after the temperature drops to 20 °C). After the whole of titanium tetrachloride has been fed, the reactive mixture is agitated for 1.5-2 hours and the reactor is continuously cooled with salt solution. 

As a result of the high ionic charge to radius ratio of titanium(IV), normal salts of titanium(IV) are difficult to prepare from aqueous solutions these often yield basic, hydrolyzed species. A tris-catechol species, [Ti(cat)3], prepared by Raymond etal. is one exception it is stable in aqueous solution up to pH 12. The catechol ligand is so stabilizing to Ti that the Ti ATi reduction potential is shifted from the value of -1-0.1V cited as the standard potential in acid in Scheme 1 to a value for [Ti(cat)3] of -1.14 V vs. NHE, affording a powerful example of ligand tuning of metal redox potential. 

Synthetic rutile has a Ti02-content of 85 to 90%. In all these processes iron is either removed in the form of a salt solution which has to be worked up or as valueless oxide. In the process for the production of titanium slag, on the other hand, metallic iron is obtained, which makes this process more interesting both ecologically and economically. As a result, a large proportion of the synthetic rutile manufacture plants has been closed down. 

In both cases the catalyst cannot be reduced to a lower degree of oxidation since trouble will arise due to precipitation of cuprous chloride. Even the palladium salt concentration which can be kept in solution depends on the degree of oxidation of the catalyst. At lower degrees of oxidation the concentration decreases due to removal from the catalyst as metallic palladium. Due to the high corrosive ability of the catalyst solution, titanium is used as construction material for all catalyst-contaning equipment. The reactor for the single-stage process is usually resin-(or ceramic)-lined. 

Preparation of TiO Colloid Solution. Titanium tetraisopropoxide (Aldrich Chemical Company) at a concentration of 5 ml in 25 ml of isopropanol, was added dropwise to 0.1 M aqueous HC1 solution while stirring. After the addition was complete, the solution was stirred for another 10 minutes and then heated slowly to remove the solvent the residue was dried under vacuum at 118°C. The Ti02 powier readily peptized in water. Aqueous colloidal solutions tended to precipitate in basic solutions addition of large amounts of inert salts also precipitated the colloids. Photoplatinization was done as reported earlier (9 ). 

For some compounds like titanium and zirconium, alkoholates are the best compounds, but for most of the metals we found that very good results can be achieved by using highly concentrated nitrate solutions. This is very important because most of the metal species are available as nitrate compounds, which are normally quite stable and can easily be handled in air. Experiments with halogenides and acetates showed a decreased surface area compared to the nitrates. As can be seen in Table 3, the surface area is higher for higher concentrated metal salt solutions. In some cases, like iron oxides, even molten nitrate compounds can be used and successfully turned into high surface area oxides. 

Numerous inorganic salts containing electrons engaged in d orbitals are responsible for transitions of weak absorption located in the -visible region. These transitions are generally responsible for their colours. That is why the solutions of metallic salts of titanium [Ti(H20)g] + or of copper [Cu(H20)g] + are blue, while potassium permanganate yields violet solutions, and so on. 

An alternative, less common, approach is the so-called secondary synthesis, whereby the metals are introduced into an already existing zeoHte framework. This approach was introduced by Skeels and Flanigen (4) and was originally used to obtain defect-free zeoHtes with a sihcon-enriched framework, which is achieved through reacting zeoHtes with fluorosihcates. In a modified procedure, zeoHtes are reacted under mild conditions with aqueous metal fluoride salt solutions (e.g., titanium fluoride or ammonium hexa-fluorotitanate). The secondary synthesis process has been successfully appHed to incorporate titanium, iron, tin, and chromium (using aqueous fluoride salts) into the framework of a number of zeoHtes. 

Eastman have patented a range of techniques for recovering monomers from aromatic polyesters. Initial intellectual property dealt with generalised schemes for methanolysis catalysed by zinc acetate, tin salts or titanium tetraisopropoxide [157, 158]. A major effort was made to develop a process which may be described as high-pressure methanolysis, in which superheated methanol is passed through a solution of scrap PET in oligomers of the same material [159-166]. Various refinements have also been made to the basic process, including addition of trace amounts of base to the reaction to prevent formation of dioxin [167], and recovery of additional aliquots of DMT from the EG stream and purification of the latter product [168-171]. 

The leaching operation is carried out fairly rapidly in a semi-continuous manner. The vessel is first filled with 2 per cent nitric acid and then further acid and coarsely ground reaction cake are added simultaneously over a period of time. The bottom valve is opened sufficiently to allow the salt solution to drain away at the same rate as fresh acid is added, so maintaining a constant liquor level in the vessel. The titanium metal remains behind on the filter until the conclusion of the run. It is then taken away as a slurry, via an exit pipe just above the filter level. The slurry is finally dewatered in a rubber-lined batch centrifuge and dried in air at a moderate temperature. 

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