Getter metals sodium-potassium

Lithium which had been purified by filtration followed by gettering with titanium and yttrium at 753 K had a lower resistivity than metal purified by other methods. For the liquid, dp/dOc was positive but decreased with increasing temperature, whereas for the solid, the value increased with increasing temperature. The resistance of dissolved oxide and hydride impurities in eutectic alloys of sodium and potassium appears to be a complex function of the concentration of each impurity, which can be attributed to chemical interaction in the metal to form hydroxide. Dissolved hydride causes a considerable increase in the resistance of the alloy but hydroxide has a much smaller effect. Dissolved lithium hydride affects the resistance of the alloy more than does sodium or potassium hydride but, again, hydroxide, as lithium hydroxide, has a smaller effect. Information on the solubility of lithium salts in liquid lithium has been critically reviewed. Recommended solubilities are provided for solutions of oxide and nitride as... 

The reduction of zirconium tetrachloride in a carrier salt with sodium as a reducing agent may be examined next. Again, as described before, complete deoxidation of the bath before reduction is the essential condition for success, if ductile metal is wanted. Zirconium tetrachloride is soluble in sodium chloride or potassium chloride (48) and a salt with about 25% zirconium tetrachloride can be melted without excessive zirconium chloride losses. Such a bath can even be obtained from powdery commercial zirconium silicide and iron dichloride, which react when heated and deliver a stream of zirconium tetrachloride, contaminated with some titanium tetrachloride and silicon tetrachloride. The gas so produced can be condensed in a fused salt bath such as potassium chloride-sodium chloride, in which only the zirconium tetrachloride dissolves (47), To obtain a low oxide metal after reduction with sodium, the conditions for fluo salt deoxidation must be observed. This process of zirconium production has no special interest, except for obtaining powder for getter purposes. A carrier salt, which might introduce oxide, is not wanted, as the reaction itself liberates sodium chloride. 

---