Prepd by heating selenium with excess potassium: Fonzes-Diacon, Contribution a l'Etudes des Séléniures Métalliques, Montpellier (1901); by adding selenium to a soln of potassium in liq ammonia: Hugot, Recherches sur l′Action du Sodammonium et du Potassammonium sur Quelque Métalloides, Paris (1900); Feher in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) p 421; by igniting potassium selenite or selenate in an atm of hydrogen: Berzelius, cited in Mellor's vol. 10, 767 (1930).