Silver nitric acid recovery

The concentrated acid is removed from the base of the column and the distillate from the top of the column. The nitric acid produced is recycled to the SILVER IF system. For the destruction of compounds containing nitrogen (e.g., energetics), a net excess of nitric acid is produced that is removed as concentrated acid from the base of the column. For organic feeds that do not contain nitrogen, all of the concentrated acid must be returned to the catholyte vessel to replace the acid reduced to NO in the cell. The anticipated ninic acid recovery is 99.5 percent. 

Total recoverable metals are defined as the concentrations of metals in an unfiltered aqueous sample treated with hot nitric and hydrochloric acids according to EPA Method 3005. The method is suitable for the preparation of digestates for the FLAA and ICP-AES analysis. This procedure is known to produce low recoveries of silver due to precipitation and of antimony due to evaporation. 

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