基于电容去离子技术的甲酸铯泥浆循环利用实验研究

Experimental study on the recycling of cesium formate mud based on capacitive deionization technology

摘要:

甲酸铯泥浆作为自然增重型泥浆，能够解决高温高压环境下固相增重剂沉降和卡磨钻的问题，在深地钻探中展现出广阔的应用前景。然而，在甲酸铯泥浆的回收过程中，可溶干扰离子的分离难度较大，限制了其循环利用与成本控制。针对这一问题，研究提出了一种基于电容去离子技术（CDI），以去除甲酸铯泥浆中的干扰离子，实现甲酸铯泥浆的循环利用，从而降低使用成本。分析了甲酸铯的理化特性及其在高温高压环境下的稳定性，通过搭建电吸附实验平台，探究了CDI技术对不同价态离子（Na⁺、Mg²⁺、Al³⁺）的去除效率及电极脱附再生性能。实验结果表明，在1.0 V电压条件下，CDI对Na⁺和Mg²⁺的去除率最高可达85.2%和67.1%，而Al³⁺去除率低于30%；脱附实验中，Na⁺、Mg²⁺、Al³⁺溶液电导率从2.47 μS/cm分别恢复至66.2、57.6、32 μS/cm，说明电极能够通过脱附实现再生。研究揭示了电压、浓度与离子电荷数对去除率的影响规律，证实CDI技术对去除泥浆中的干扰离子具有一定潜力。本研究为甲酸铯泥浆的绿色循环利用提供了新思路。

Abstract:

As a natural weight-increasing mud， cesium formate mud can solve the problems of solid phase weighting agent sedimentation and sticking in a high-temperature and high-pressure environment， and shows a broad application prospect in deep drilling. However， in the recovery process of cesium formate mud， the separation of soluble interfering ions is difficult， which limits its recycling and cost control. In order to solve this problem， a treatment method based on capacitive deionization technology （CDI） is proposed to remove the interfering ions in the cesium formate mud， realize the recycling of the cesium formate mud and reduce the cost of use. The physical and chemical properties of cesium formate and its stability in a high-temperature and high-pressure environment were analyzed. The removal efficiency of different valence ions （Na⁺， Mg²⁺， Al³⁺） and the desorption and regeneration performance of the electrode were investigated by constructing an electrosorption experimental platform. The experimental results show that the removal rate of Na⁺ and Mg²⁺ by CDI can reach 85.2 % and 67.1 %， while the removal rate of Al³⁺ is less than 30 % under 1.0V. In the desorption experiment， the conductivity of Na⁺， Mg²⁺ and Al³⁺ solutions recovered from 2.47μS/cm to 66.2， 57.6， 32μS/cm， respectively， indicating that the electrode could be regenerated by desorption. The study reveals the influence of voltage， concentration and ion charge number on the removal rate， and confirms that CDI technology has certain potential for removing interfering ions in mud. This study provides a new idea for the green recycling of cesium formate mud.