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Views: 726 Author: VV Publish Time: 2016-10-24 Origin: Rech Chemical Co. LTD
Please check the national standard of zinc sulfate as foolow:
zinc sulfate Industry grade is classified into two categories: Ⅰ for zinc sulfate monohydrate, Ⅱ for zinc sulfate heptahydrate.
| Item | The indexes | |||||
| Ⅰ | Ⅱ | |||||
| High | fine | qualified | High | fine | qualified | |
| The mass fraction of zinc % ≧ | 35.7 | 35.34 | 34.61 | 22.51 | 22.06 | 20.92 |
| The mass fraction of zinc sulfate monohydrate % ≧ | 98.0 | 97.0 | 95.0 | — | — | — |
| The mass fraction of zinc sulfate heptahydrate % ≧ | — | — | — | 99.0 | 97.0 | 92.0 |
| The mass faction of insoluble matter % ≦ | 0.020 | 0.050 | 0.10 | 0.02 | 0.050 | 0.10 |
| PH Value（50g/L solution） ≧ | 4.0 | 4.0 | — | 3.0 | 3.0 | — |
| The mass faction of chloride（Cl）% ≦ | 0.20 | 0.60 | — | 0.20 | 0.60 | — |
| The mass faction of lead（Pb）% ≦ | 0.002 | 0.007 | 0.010 | 0.001 | 0.010 | 0.010 |
| The mass faction of ferric（Fe）% ≦ | 0.008 | 0.020 | 0.060 | 0.003 | 0.020 | 0.060 |
| The mass faction of manganese（Mn）% ≦ | 0.01 | 0.03 | 0.05 | 0.005 | 0.10 | — |
| The mass faction of Cadmium（Cd）% ≦ | 0.002 | 0.007 | 0.010 | 0.001 | 0.010 | — |
The notes for testing zinc content method in this standard: add ammonium chloride and potassium in zinc sulfate solution to eliminate the interference of impurity as copper, iron. Under the conditions of about pH5.5 and indicated by two cresol orange, the solution is titrated with EDTA (Ethylene Diamine Tetraacetic Acid).
