To provide a method for producing a silver of the high purity metallic silver having 99.999 mass% with which the metallic silver can be obtained from a refining intermediate material containing difficult to solve silver compound.
The method for producing the silver from the refining intermediate material includes: a process (1) in which the refining intermediate material is leached into sulfite water solution and the silver is extracted in the solution, and successively, the generated non-soluble residue is separated to obtain the leaching solution containing the silver; a process (2) in which an acid is added into the leaching solution and the precipitated material containing the silver chloride is obtained; a process (3) in which the precipitated material is oxidize-treated in acidic water-solution and the impurity elements are eluted and successively, the solution containing impurities is separated to obtain the purified silver chloride; and a process (4) in which the silver chloride is reduced in alkali-water solution to obtain the silver powder. When an oxide is added in the above process (2), pH is adjusted to 3.5-5.5 and after precipitating a silver chloride, the whole quantity of a mother liquid and a precipitated material is immediately filtrated, and the precipitated material is separated from the mother liquid.
COPYRIGHT: (C)2009,JPO&INPIT
Yasushi Isshiki
Takashi Hashikawa
Satoshi Asano
| JP9316559A | ||||
| JP10158752A | ||||
| JP2005060832A | ||||
| JP2002256352A |
| WO2005023716A1 |