Abstract: A method and apparatus for separating the spheres from the non-spheres in a large number of particles of lamp fill material of substantially equal mass in which the spheres are placed in the grooves of an inclined surface to roll downwardly thereon under the influence of gravity. The grooves are configured to limit the contact with the particles to two points intermediate the depth of the groove so as to keep the particles out of contact with the bottom of the groove. Vacuum pick-up means are used to remove those particles which do not roll down the grooves because of their spherical irregularities. The surfaces in contact with the lamp fill material are made of stainless steel and the entire operation is conducted within the confines of a dry box to minimize contamination.

Abstract: Substantially pure, free flowing, sodium amalgam particles of predetermined composition and controlled particle size are prepared for use as vaporizable fill for high pressure discharge lamp devices, whereby accurately measurable quantities of the sodium amalgam may be introduced into the lamp devices. A process for producing the substantially pure amalgam particles of accurately controlled size includes heating a mixture of sodium and mercury to form a melt, passing the melt through a vibrating discharge nozzle and subjecting the droplets so formed to an inert cooling fluid maintained at a temperature below the solidification point of the amalgam. An apparatus for producing the amalgam particles comprises a vessel to contain an alkali metal amalgam melt, a vibrating discharge nozzle adapted to form the melt into uniformly sized droplets, and a column of inert cooling fluid maintained at a low temperature at which the melt droplets are solidified.