从高银低钯硝酸溶液中分离银和钯

Silver and Palladium Separation from Hydrogen Nitrate Solution with Low Ag and High Pd Content

银钯分离目前普遍采用Cl-沉淀法，但从高银低钯硝酸溶液中分离银和钯，Cl-沉淀法操作过程长，消耗化药多，成本高．提出水解法分离银钯新工艺，首先通过热力学计算，证明水解法是可行的．在常温下，向银钯的硝酸溶液中加NaOH溶液，控制pH＝3～5，钯呈Pd（OH）2沉淀而与银分离，再向滤液中加入盐酸使银沉淀，滤出AgCl后，用NaOH调PH为7～8使钯完全沉淀．通过实践证明用水解法从高银低钯的硝酸溶液中分离银和钯工艺合理。

Cl- precipitation method is commonly used for the separation of Ag and Pd. The method, however, has longer operation duration , more chemical consumption and higher cost to separate Ag and Pd from hgdrogen nitrate solution of low Ag and high Pd content. A new method of hydrolysis is proposed, which is proved feasible from thermodynamic calculation:adding NaOH solution into hydrogen nitrate solution with Ag and Pd at room temperature, keeping pH= 3~5 to make Pd precipitated in the form of Pd (OH)2 and separated from Ag; adding HCl into the filtered solution to make Ag precipitated ; filtering out AgCl , adding NaOH and keeping pH= 7~8 to make Pd precipitated fully. It is proved from the practice that the merthod has reasonable technology and low cost.