Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1817798 | Physica C: Superconductivity and its Applications | 2014 | 5 Pages |
The magnetic separation experiment to collect the Ni compounds from the waste liquid of electroless plating processes was conducted in the open-gradient magnetic separation process with the high temperature superconducting bulk magnet system. The magnetic pole containing Gd-based bulk superconductors was activated to 3.45 T at 35 K in the static magnetic field of 5 T with use of a superconducting solenoid magnet. The coarse Ni-sulfate crystals were formed by adding the concentrated sulfuric acid to the Ni-phosphite precipitates which yielded from the plating waste liquid by controlling the temperature and the pH value. The open-gradient magnetic separation technique was employed to separate the Ni-sulfate crystals from the mixture of the Ni-sulfate and Ni-phosphite compounds by the difference between their magnetic properties. And we succeeded in collecting Ni-sulfate crystals preferentially to the Ni-phosphite by attracting them to the magnetic pole soon after the Ni-sulfate crystals began to grow.
► The magnetic separation for Ni compounds was conducted by HTS bulk magnet. ► The coarse Ni-sulfate crystals were formed from the Ni-phosphite precipitates. ► Ni-sulfate crystals was separated from the mixture of Ni-sulfate and Ni-phosphite compounds.