SELENIUM COMPOSITION PURIFICATION PROCESS SELENIUM COMPOSITION PURIFICATION PROCESS

摘要

1375846 Selenium; arsenic selenide XEROX CORP 6 Dec 1971 [7 Dec 1970] 56522/71 Heading C1A Xerographically pure selenium-containing material (e.g. selenium or arsenic selenide) is recovered from xerographically impure selenium-containing material by dissolving it in an aqueous alkali metal hydroxide solution under substantially non-oxidative conditions (as defined), precipitating purified selenium-containing material by adding acid to render the solution strongly acidic, and washing the precipitate to remove residual impurities. The impure material may be dissolved in 20-25% NaOH heated to about 90‹ C. Hydrochloric acid may be added with agitation until the pH of the solution is between 1 and 2. After washing the precipitate may be dried. When the impure material is an arsenic-selenium alloy the precipitate may be vacuum dried and remelted at 600‹ C. to form arsenic triselenide.