钻井固化废弃物表面涂覆工艺的正交实验优化及效果评价

Orthogonal experiment optimization and effect evaluation of surface coating on solidified drilling waste materials

针对钻井废弃物固化处理之后存在的二次浸出污染问题,通过正交实验优化,得到一种钻井废弃物表面涂覆技术,采用吸水率测试仪、接触角测量仪、扫描电子显微镜、红外光谱仪等仪器对涂覆固化物的防水性能、环保性能和耐久性能进行测试,并对涂覆层微观结构进行分析,进一步探究其作用机理。结果表明:钻井废弃物经涂覆后,吸水率为3.04%,表面接触角为79.56°,表现出良好的防水性;浸出液化学需氧量达到国家一级标准,固化处理未能全部封固的Cd、Mn以及其他重金属离子均未检出,具备良好的环境相容性;浸泡在10%HCl和10%H_(2)SO_(4)溶液环境下7 d强度损失率均小于50%,耐水、耐酸性较强。微观结构显示涂覆材料能够渗入废弃物的孔隙结构中,在废弃物表面形成密闭的疏水层,所以表面涂覆技术能够显著提高钻井废弃物的环保性能和耐久性,初步体现资源化利用价值。

In order to solve the problems of the secondary leaching pollution after the solidification treatment of the drilling wastes,a surface coating technology was obtained through the orthogonal experiment optimization.The water absorption,contact angle,scanning electron microscope,infrared spectrometer and other methods were carried out to investigate the waterproof performance,environmental protection performance and durability performance.The microstructure of the coating layer was analyzed to further explore its mechanism.Results showed that the coated drilling wastes indicated a well waterproof performance with the water absorption rate of 3.04%and the surface contact angle of 79.56°.The COD value of the leaching solution reached the PRC national Grade I discharging standard.Meanwhile,the Cd,Mn and other heavy metal ions without completely sealing by the curing treatment were not detected,thus showing a good environmental performance.After soaking in the 10%HCl and 10%H_(2)SO_(4) solution,the 7-days strength loss rate of the coated drilling wastes was less than 50%.The microstructure showed that the coating material penetrated into the pore structure of the wastes and formed a closed hydrophobic layer on its surface.Therefore,the surface coating technology can significantly improve the environmental performance and durability of the drilling wastes,indicating a value of resource utilization.