Preparation: |
milled and sieved; pretreated with analytical grade KClO4 to exchange Ca and Na impurities
with K from biotite surface’s sorption sites as further specified in (Armarego and Chai, 2012; Li et al., 2020); fifty grams of the crushed biotite sample was packed into a glass cation exchange column and 0.1 M KClO4 was pumped through the column with a peristaltic pump at the flow rate of 4 ml/h for two weeks; for the last two days of wash, 0.01 M KClO4 and MilliQ-water were pumped through the column to remove excess K; dried in a vacuum oven overnight |