四苯硼钠溶液中含钾矿物非交换态钾的释放特性研究

Release characters of non-exchangeable potassium from potassium bearing minerals in NaBPh_4 solutions

含钾矿物的全钾含量、非交换态钾总量以及非交换态钾的释放速率因矿物种类而异,且3种参数之间没有必然的相关性。供试5种含钾矿物非交换态钾总量由高到低的顺序是金云母5.19%>黑云母3.08%>蛭石2.01%>白云母1.18%>钾长石0.24%,占各矿物全钾的比例分别为58.4%、99.7%、62.5%、14.2%和4.98%,平均达48%。选择较弱提取力的四苯硼钠溶液进行非交换态钾的释放特性研究,5种矿物非交换态钾3 d释放累积量顺序为黑云母>蛭石>金云母≥白云母>钾长石;非交换态钾平均释放速率也表现为同样的顺序。上述5种矿物在弱提取力的四苯硼钠溶液中释放3 d,非交换态钾的平均释放速率分别为5.99、2.34、0.52、0.22和0.17 mg/(kg.min),差异明显。如何根据非交换态钾的释放量和释放速率来综合评价矿物钾的生物有效性是未来研究中需要明确的问题。

The total K content,total non-exchangeable potassium（NEK） content and NEK release rate of five K-bearing minerals（phlogopite,biotite,vermiculite,muscovite and feldspar） were compared in current study.The results indicated that the total K,total NEK and NEK release rates of the minerals differed greatly,and the three parameters were not significant correlated.The total NEK content followed the order of phlogopite（5.19%） biotite（3.08%） vermiculite（2.01%） muscovite（1.18%） feldspar（0.24%）,accounting for 58.4%,99.7%,62.5%,14.2% and 4.98% of the total K,respectively.The release characteristics of the NEK from five minerals was investigated during a 3 d extraction with NaBPh4 method with low K-extracting power,the amount of NEK released from minerals followed the sequence of biotite vermiculite phlogopite muscovite feldspar.The averaged NEK release rates from five minerals followed the same order and were 5.99,2.34,0.52,0.22 and 0.17 mg/（kg·min）,respectively.How to evaluate the K availability in minerals according to the amount and the release rate of NEK was still a question need to be addressed in future.