Process for producing substances optically transparent to infrared rays

Claim 1

In the production of shaped glass articles transparent to infrared radiation from chalcogenides, the improvement which consists of the process of forming said chalcogenides by the steps of: (a) vaporizing in a first vessel at least one chalcogen hydride selected from the group which consists of dihydrogen sulfide, dihydrogen selenide and dihydrogen telluride to produce a chalcogen hydride vapor; (b) vaporizing in a second vessel at least one chloride salt of a metal or metalloid selected from the group which consists of As, Sb, Zn, Ge, Sn, P, Si and Cd to produce a vapor thereof; (c) separately feeding the vapors produced in steps (a) and (b) to a reaction chamber containing only said vapors and preheated to a temperature below the melting point of said chalcogenides but sufficient to induce reaction of said vapors in said chamber to produce said chalcogenides; (d) effectuating said reaction in said chamber by double substitution under nonreducing and nonoxidizing conditions at a temperature below the melting point of said composition, thereby precipitating the chalcogenides as a solid from the reaction in said chamber; and (e) discharging the precipitated chalcogenides in solid form from an outlet of said chamber.