Patent ID: 7563429
Filing Date: 2009-07-21
Classification: B01D,C01B,C01G,C22B,Y02P

Abstract:
1. A process for reclaiming spent selenium filter mass comprised of an inert material, residual selenium active substance and mercury selenide, said process comprising: treating the spent selenium filter mass with a hydrogen peroxide solution for leaching out the selenium content in essentially all of the residual selenium active substance so as to form selenious acid and treated spent selenium filter mass; separating the selenious acid from the treated spent selenium filter mass; contacting the treated spent selenium filter mass with aqua regia solution, thereby dissolving essentially all the mercury selenide and producing a treated spent mercury selenide-depleted filter mass; separating the aqua regia solution containing the dissolved mercury selenide from the treated spent mercury selenide-depleted filter mass; and precipitating the mercury in disposable form from the aqua regia solution containing the dissolved mercury selenide to produce a mercury-depleted aqua regia solution, and separating the precipitated mercury from the mercury-depleted aqua regia solution.