Heating mixed solutions containing manganese sulfate, ammonium peroxodisulfate and ammonium sulfate at a molar ratio of 1:1:5 at 150°C gave NH4-cryptomelane. The higher the starting manganese concentration, the higher the purity of the products. At a concentration of 0.5 mol/L any products other than NH4-cryptomelane was detected. Column washing with 6 mol/L nitric acid was found to be suitable for exchanging NH4 + with H+. The H-exchanged cryptomelanes were highly selective for K and the K adsorption capacity increased as the volume of nitric acid used for washing increased. The maximum adsorption capacity achieved in this study was about 800 mmol/kg.
|Number of pages||5|
|Journal||Journal of the Faculty of Agriculture, Kyushu University|
|Publication status||Published - Feb 1 2016|
All Science Journal Classification (ASJC) codes
- Agronomy and Crop Science