Potassium vanadate

Imports and Exports. The United States has long been a significant importer of vanadium slags, but imports of pentoxide were negligible until they rose quickly to 850 metric tons ia 1974, and 2000 t ia 1975 (mostly from the Repubhc of South Africa). Peatoxide imports thea decliaed to 1400 t ia 1980 with Finland being the maia and South Africa the minor suppHers. In recent years, U.S. imports of ammonium and potassium vanadates and of other vanadium compounds have been 100—200 t/yr, mainly from the U.K., Germany, and the RepubHc of South Africa. 

Vniios A process for catalytically pyrolyzing hydrocarbons to low molecular weight alkenes, similar to catalytic cracking but more efficient. The catalyst is either potassium vanadate on corundum or indium oxide on pumice. Developed by the All-Union Research Institute for Organic Synthesis, Moscow. 

Potassium vanadous thiocyanate, 8KSCN.V(SCN)3.4H20 bright red crystals. 

Gasior et al.96 studied a number of potassium vanadates which, under reaction conditions decompose to the so-called i//-phase and V6013. The latter is taken to be the active phase being stabilized by the former, because under reaction conditions pure V6013 is oxidized to V2O5. 

Sodium and potassium vanadates. The authors [68] investigated mechanochemical synthesis of sodium and potassium decavanadates starting from V Oj and conesponding carbonates or metavanadates. They have shown that varying the initial ratio of components and the time of mechanical activation of the mixtures, the synthesis of different vanadates, including decavanadates, occurs, characterized by high rate of reactions. 

Carnotite K2O 2U2O3 V2O5 3 H2O (uranium potassium vanadate) ... 

Only in the case of samples with KA/ atomic ratios higher than 0.7, potassium oxide or potassium vanadate could be formed which could favor a low formation rate of propylene but also a high deep oxidation of propylene. In fact, a low selectivity to propylene has been observed on sample K(0.9) (Fig. 6), indicating that carbon oxides are directly formed from propane on samples with high K-contents. 

Additionally, a potassium vanadate (KV3O8) was synthesised according to a method described by Kelmers [22]. 45.49 g (0.25 mol) V2O5 were introduced stepwise into a solution of 28.14 g (0.5 mol) KOH in 500 ml distilled water during 30 min. 3 ml H2O2 (30%) were added to get complete vanadium(V). After filtration the solution was heated up to 353 K under vigorous stirring and... 

EINECS 237-388-8 K-Van Potassium m-vanadate Potassium metavanadate Potassium trioxovanadate Potassium vanadate Potassium vanadate(V) (KVO3) Potassium vanadium trioxide UN2854 Vanadate (V03 ), potassium Vanadic acid, potassium salt. Crystals mp = 520" d = 2,840, Kerr-McGee. 

The oxidation of SOi to sulfuric acid, SOt + H2O + 0.5 O2 H2SO4, is catalyzed by potassium vanadium(V) oxide compounds. A typical catalyst preparation sequence involves impregnation of a silica support with a solution containing potassium vanadate (K/V = 3), followed by drying and subsequent calcination at 500°C in air. Under typical operating conditions in SO2/O2/SO3 atmospheres at 400-500°C, the catalytically active species is molten and forms a thin liquid film on the silica. support. As such the. system functions like a bulk oxide catalyst under operating conditions, and the silica mostly serves as a mechanical support medium. 

The major primary ore mineral is uraninite (basically UO2) or pitchblende (U2O5.UO3, better known as U3O8), though a range of other uranium minerals are found in particular deposits. These include camotite (uranium potassium vanadate), the davidite-brannerite-absite-type uranium titanates, and the euxenite-fergusonite-samarskite group (niobates of uranium and rare earths). 

Potassium phosphate see phosphoric acid, tripotassium salt Potassium vanadate see vanadic acid, dipotassium salt 2-Propanone (aqueous)... 

FIGURE 3. Light-induced biphasic (I,II) proton efflux in Anabaena varia-bilis is inhibited by vanadate. The numbers indicate proton efflux in mol H /mg Chi x h, taking into consideration the buffer capacity of 1 mM potassium vanadate. Calibration of proton efflux is shown only for the control. Chlorophyll concentration was 30 hg/ml. 

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