Zirconium dissolved

Zirconium Dissolve 3.533 g ZrOCl2 8H2O in 50 ml of 2 M HCl, and dilute to volume. Solution... 

Zirconium may lie removed hy fusing the oxides with KIlFj and extracting with water acidified with UK. The zirconium dissolves, forming K-ZrK, hut both < thorium fluorides are insoluble,... 

Criticality Analysis of the ICPP Zirconium Dissolver Using MONK, /. E. Fergus (Exxon Nuclear Idaho), B. J. Layman (Rockwell Hanford)... 

Hexafluorozirconic acid [12021 -95-3]], H2ZrP, is formed by dissolving freshly prepared oxide, fluoride, or carbonate of zirconium in aqueous HP. This acid is produced commercially in a concentration range of 10 to 47%. The acid can be stored at ambient temperatures in polyethylene or Teflon containers... 

Hulls Handling. After the fuel has been dissolved, the residual pieces of zirconium cladding, referred to as hulls, are rinsed and removed from the dissolver vessel. The decay of activation products provides sufficient heat to ensure drying of the hulls and preclude hydrogen formation caused by the radiolysis of water. 

Two zirconium-containing minerals were discovered in North America, namely, welognite [55659-01-3] (Sr2 g Cag 2 )ZrNa2(C03 )g -3H2 0, and gittinsite [75331-27-0] Unlike zircon, the zirconium content of these minerals and eudialyte can be dissolved by strong acid. 

Obtaining pure ductile zirconium by reduction of the oxide is particularly difficult because of the tendency of hot zirconium to dissolve considerable amounts of oxygen, making the metal britde at room temperature. Therefore, it is common practice to reduce oxygen-free zirconium tetrachloride. 

Hydrides. Zirconium hydride [7704-99-6] in powder form was produced by the reduction of zirconium oxide with calcium hydride in a bomb reactor. However, the workup was hazardous and many fires and explosions occurred when the calcium oxide was dissolved with hydrochloric acid to recover the hydride powder. With the ready availabiHty of zirconium metal via the KroU process, zirconium hydride can be obtained by exothermic absorption of hydrogen by pure zirconium, usually highly porous sponge. The heat of formation is 167.4 J / mol (40 kcal/mol) hydrogen absorbed. 

Zirconium carbide is inert to most reagents but is dissolved by hydrofluoric acid solutions which also contain nitrate or peroxide ions, and by hot concentrated sulfuric acid. Zirconium carbide reacts exothermically with halogens above 250°C to form zirconium tetrahaHdes, and with oxidizers to zirconium dioxide in ak above 700°C. Zirconium carbide forms soHd solutions with other transition-metal carbides and most of the transition-metal... 

Zirconium nitride is dissolved by concentrated hydrofluoric acid, dissolved slowly by hot concentrated sulfuric acid, and oxidizes to zirconium oxide above 700°C in air. 

Zirconium tetrafluoride dissolves in dilute acid without hydrolysis, and can be recovered as the monohydrate [14956-11-3] by crystallization from nitric acid solutions. If the solution is acidified with hydrofluoric acid, ZtF 3H20 [14517-16-9] crystallizes at 10—30 wt % HF HZtF 20 [18129-16-9] crystallizes at 30—35 wt % HF, and at higher HF concentrations H2ZtF -2H20 [12021 -95-3] can be recovered. 

Oxide Chlorides. Zirconium oxide dichloride, ZrOCl2 -8H2 0 [13520-92-8] commonly called zirconium oxychloride, is really a hydroxyl chloride, [Zr4(OH)g T6H2 0]Clg T2H2O (189). Zirconium oxychloride is produced commercially by caustic fusion of zircon, followed by water washing to remove sodium siUcate and to hydrolyze the sodium zirconate the wet filter pulp is dissolved in hot hydrochloric acid, and ZrOCl2 -8H2 O is recovered from the solution by crystallization. An aqueous solution is also produced by the dissolution and hydrolysis of zirconium tetrachloride in water, or by the addition of hydrochloric acid to zirconium carbonate. 

Zirconium hydroxy oxychloride [18428-88-17, nominally ZrO(OH)Cl, is produced by dissolving hydrous zirconia in hydrochloric acid in an equal molar proportion, and is available only in solution. Other oxychlorides with Cl Zr ratios <2 are discussed in Reference 199. 

Carbonates. Basic zirconium carbonate [37356-18-6] is produced in a two-step process in which zirconium is precipitated as a basic sulfate from an oxychloride solution. The carbonate is formed by an exchange reaction between a water slurry of basic zirconium sulfate and sodium carbonate or ammonium carbonate at 80°C (203). The particulate product is easily filtered. Freshly precipitated zirconium hydroxide, dispersed in water under carbon dioxide in a pressure vessel at ca 200—300 kPa (2—3 atm), absorbs carbon dioxide to form the basic zirconium carbonate (204). Washed free of other anions, it can be dissolved in organic acids such as lactic, acetic, citric, oxaUc, and tartaric to form zirconium oxy salts of these acids. 

Assay of beryUium metal and beryUium compounds is usuaUy accompHshed by titration. The sample is dissolved in sulfuric acid. Solution pH is adjusted to 8.5 using sodium hydroxide. The beryUium hydroxide precipitate is redissolved by addition of excess sodium fluoride. Liberated hydroxide is titrated with sulfuric acid. The beryUium content of the sample is calculated from the titration volume. Standards containing known beryUium concentrations must be analyzed along with the samples, as complexation of beryUium by fluoride is not quantitative. Titration rate and hold times ate critical therefore use of an automatic titrator is recommended. Other fluotide-complexing elements such as aluminum, sUicon, zirconium, hafnium, uranium, thorium, and rate earth elements must be absent, or must be corrected for if present in smaU amounts. Copper-beryUium and nickel—beryUium aUoys can be analyzed by titration if the beryUium is first separated from copper, nickel, and cobalt by ammonium hydroxide precipitation (15,16). 

Borides are inert toward nonoxidizing acids however, a few, such as Be2B and MgB2, react with aqueous acids to form boron hydrides. Most borides dissolve in oxidizing acids such as nitric or hot sulfuric acid and they ate also readily attacked by hot alkaline salt melts or fused alkaU peroxides, forming the mote stable borates. In dry air, where a protective oxide film can be preserved, borides ate relatively resistant to oxidation. For example, the borides of vanadium, niobium, tantalum, molybdenum, and tungsten do not oxidize appreciably in air up to temperatures of 1000—1200°C. Zirconium and titanium borides ate fairly resistant up to 1400°C. Engineering and other properties of refractory metal borides have been summarized (1). 

Dissolve 1 g zirconium(IV) oxide chloride octahydrate (zirconyl chloride) in 50 ml methanol. 

Spray solution Dissolve 2 to 25 g zirconium(IV) oxide chloride octahydrate in 100 ml methanol [1], ethanol — water (55 + 15) [5] or water [4]. 

TLC spectrophotometry is used to determine zirconium in Mg-Al alloy. For this purpose, the alloy sample (2 g) is dissolved in HNO3 (20 ml, 6 M), and zirconium is extracted in 6 ml of 0.02-M diantipyrilmethane (DAM) solution in chloroform. The extract was concentrated to 0.4 ml and an aliquot (10 p,l) was chromatographed on silica gel LS plate using 4-M HCl -f dimethylformamide (1 2) as the mobile phase. After development, the portion of the sorbent layer containing the zirconium-DAM complex was removed, and the metal was extracted with 6-M HCl. The zirconium present in this solution was determined in the form of a xylenol orange complex (Amax, 540 nm) by spectrophotometry [22]. 

The introduction of enamel into the wastestream results in an increase in the concentration of metals, but these metals (antimony, titanium, zirconium, tin, cobalt, and manganese) are in solid form whereas the metals generated by surface preparation are normally in dissolved form. These solid metals increase the suspended solids concentration of the stream. Other metals that may be found in the enamel preparation and application wastestream in significant amounts include aluminum, copper, iron, lead, nickel, and zinc. Table 8.2 presents pollutant sampling data for the processes used in the porcelain enameling on steel industry. 

In a method described by Yoshimura and Uzawa [ 144], cadmium in seawater is coprecipitated with zirconium hydroxide (Zr(OH)4) prior to determination by square-wave polarography. The precipitate is dissolved in hydrochloric acid, and cadmium concentration is determined from the peak height of the... 

GZO films were electrodeposited from an electrodeposition bath containing 0.29-g gadolinium halide and 0.1-g zirconium halide dissolved in a 150-mL electrolyte solution. Electrodeposition was performed at a current density of 1 mA/cm2 and under constant stirring in a vertical two-electrode cell configuration. The average rate of deposition was about 25 nm/min. 

In this method the sediment is pretreated with 2g solid sodium hydroxide in a zirconium crucible which is then heated to 350°C for 2h. The fused mass is dissolved in 40ml 0.2N hydrochloric acid, then further treated with 20ml... 

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