不同酸对水泥石表面的刻蚀作用

酸类物质对水泥有强的腐蚀作用,不同酸在水泥内部作用机理不同。以盐酸、氢氟酸为主要试剂,通过静态浸泡实验探究各酸剂对硬化水泥石的溶解分散效果,利用扫描电镜、偏光显微镜、X射线能谱仪等测试方法对不同酸刻蚀后的水泥石表面进行界面组成与结构分析,探究其表面刻蚀的变化规律,进而分析不同酸清洗水泥沉积垢层的清洗机理,为清洗工艺的优化提供理论依据。结果表明,盐酸中水泥残余物主要为Si O2,氢氟酸中残余物主要为Ca F2;氢氟酸对水泥中球状分散颗粒的分解作用明显,能破坏水泥间的胶黏性,使其产生晶体缺陷,有助于水泥石的分解。这一研究结果对指导清洗剂配制,快速清除固井中残存在容器、管道中的固化水泥有重要意义。

Corrosion of Surface of Set Cement by Different Acids

Acids have strong corrosion to cement; different acids corrode cement in different mechanisms. The solution and dispersion of set cement in hydrochloric acid and hydrofluoric acid were studied by static soaking of set cement in these acids. Using SEM, polarized light microscope and X-ray energy spectrometer, the surface composition and textures of set cement being corroded by acids can be measured. These studies helped understand the cleansing of cement scales with acids. When dissolved in hydrochloric acid, the residue of cement was mainly SiO2, and when dissolved in hydrofluoric acid, the residue became CaF2. Hydrofluoric acid dispersed ball-shaped cement remarkably, and can damage the adhesion of cement, producing crystal defect in cement which accelerated the disintegration of set cement. This study will play important roles in the preparation of cleansing fluid and in fast cleansing of set cement remained in containers and pipes.