Process and apparatus for precipitating and recovering silver and mercury from spent, titrated solutions, which are strongly acid with sulphuric acid, for the determination of chemical oxygen demand

摘要

The process for precipitating and recovering silver and mercury from spent, titrated solutions, which are strongly acid with sulphuric acid, for the determination of chemical oxygen demand is carried out by adding comminuted copper metal to the spent, titrated solutions, which are strongly acid with sulphuric acid, and by silver and mercury present in solution being precipitated as amalgam on the comminuted copper metal. The copper-silver amalgam is washed and dried. The mercury is recovered by distillation and the silver is recovered by metallurgical separation. The apparatus has a sedimentation vessel for the spent, titrated solutions, which are strongly acid with sulphuric acid, at least one reaction vessel and/or at least one reaction column, and also a filtration facility arranged downstream of the reaction vessel (reaction column) for drying the copper-silver amalgam.