ChemicalBook CAS DataBase List Potassium

Potassium synthesis

4synthesis methods

Product Name:Potassium
CAS Number:7440-09-7
Molecular formula:K
Molecular Weight:39.1

Potassium metal is not produced commercially by a fused salt electrolysis of the chloride —as is sodium—for several reasons: the metal is too soluble in the molten chloride to separate and float on top of the bath; potassium metal vapors may also issue from the molten bath, thus creating hazardous conditions; and potassium superoxide may form in the cell and react explosively with potassium metal. Consequently, the established method of preparing potassium metal commercially? involves the reduction of molten potassium chloride by metallic sodium at elevated temperatures (850°C). Molten potassium chloride is fed into the midpoint of a steel vessel provided with a fractionating tower packed with stainless steel rings. Sodium is vaporized at the bottom and rises countercurrent to the molten potassium chloride with which it reacts according to the equilibrium expression.
Although the left-hand side of the equation is favored thermodynamically, the escape of the potassium vapors causes the reaction to proceed very efficiently to the right. The potassium vapors are condensed and the product normally contains sodium metal as the only major impurity up to about 1 % by weight. This product is sometimes purified by fractionating it in a 38 ft high 316 stainless steel tower equipped with a reflux return reservoir. The condensate is potassium metal of 99.99 % purity.

20762-60-1
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$59.70/25g

7440-09-7
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$59.10/1g

Yield:7440-09-7 80%

Reaction Conditions:

in neat (no solvent)byproducts: N; heating 10-12g KN3 (fine powder) to 355°C (high vacuum, electrically heated tube from instrument glass (Jena)), decompn. starts sometimes 3-4h after obtaining temp., synthesis lasts some d;; spectroscopically pure and gas-free K obtained;;

References:

Suhrmann, R.;Clusius, K. [Zeitschrift fur anorganische Chemie,1926,vol. 152,p. 52 - 52] [Gmelin Handbuch der Anorganischen Chemie,Gmelin Handbook: K: MVol.1, 9, page 63 - 65]

20762-60-1
50 suppliers
$59.70/25g