Abstract: A method for making stir-in type halophosphate phosphors to obtain a fluffy, deagglomerated powder is disclosed. A wet phosphor filter cake is fed into a toroidal-shaped direct-fired glass flash dryer in which a hot gaseous stream is circulating. The wet phosphor particles are suspended in the stream while the remaining liquid is evaporated. The dried phosphor powder is ejected from the dryer by centrifugal force and collected. Recovery efficiency of the process is about 99.9 percent.

Abstract: A method is disclosed for producing alkaline earth halophosphate stir-in phosphors which comprises forming a mixture of about 55% to 75% calcium monohydrogen phosphate, about 15% to 35% calcium carbonate, about 2% to 20% ammonium chloride, about 1% to 15% manganese carbonate, about 1% to 15% antimony trioxide, and about 2% to 10% by weight calcium fluoride, wherein the average particle size of the calcium monohydrogen phosphate by Fisher subseive size is about 4.6 to 6.8 micrometers in diameter and the 50% Coulter Counter size is about 9.0 to 11.5, firing in a non-reacting atmosphere at 600.degree. C. to 1300.degree. C.

Abstract: In the manufacture of an alkaline earth halophosphate phosphor, the phosphor ingredients are mixed, fired, wet milled and dried. By sieving the material part way through the wet milling process and by sifting the dry phosphor powder, the phosphor powder weight in fluorescent lamps can be reduced.