低温条件下微波对钾长石溶出性能影响的微观机理分析

目前利用钾长石提钾的工艺研究多为过程复杂且能量损耗较大,本文提出了一种利用微波辐射协助水热反应提钾的新方法。采用微波辐射预处理钾长石粉末,加热迅速,再通过低温条件下的水热反应体系溶出钾离子,对此过程中微波辐射时间,微波辐射功率因素对钾溶出率的影响进行研究,并通过SEM、XRD等表征手段对反应后滤渣进行微观分析。优化工艺条件可以得出,在微波辐射功率600W、微波辐射时间15min、水热反应时间180min、水热反应温度180℃时效果最佳。研究结果表明:最优条件下,钾的溶出率达92%;微波辐射使钾长石预处理后表面发生变化,生成K_0.85Na_0.15AlSiO₄等产物,提高了钾长石的溶出性能;反应生成水羟方钠石Na₈Al₆Si₆O₂₄(OH)₂(H₂O)₂];有效节约了反应时间和反应过程中的能量损耗。

Microscopic mechanism of microwave effect on the dissolution of potassium feldspar under low temperature condition

At present, the processes of potassium extraction form potassium feldspar were more complex and the energy consumption was large. In this paper, a new method of hydrothermal reaction for potassium extraction assisted with microwave radiation was proposed. The potassium feldspar was pretreated by microwave radiation, and then potassium ions were extracted by hydrothermal reaction system at low temperature. The effects of microwave radiation time and microwave radiation power on the dissolution rate of potassium were studied, and the phases and microstructure of specimens after different conditions of extraction were investigated using X-ray diffraction(XRD) and scanning electron microscopy(SEM). Through adjustment and optimization of reaction conditions, the optimum conditions was obtained when microwave irradiation power of 600W, the microwave irradiation time of 15min, the temperature of 180℃ and the hydrothermal reaction time of 180min. The results showed that the dissolution rate of potassium by 92% under the optimal conditions. Microwave radiation made changes in the surface potassium extraction of the residues before and after the pretreatment of potassium feldspar which generated products like K_0.85Na_0.15AlSiO₄, and increased the dissolution properties of potassium feldspar. New product such as Na₈Al₆Si₆O₂₄(OH)₂(H₂O)₂ was generated after reaction. This method can effectively save the reaction time and energy in the process during the reaction.