Sodium-modification of Ca-based bentonite via semidry process

摘要

In order to improve the quality of Hunyuan inferior Ca-based bentonite(Ca-Bent),semidry process was used to modify Ca-Bent into superior Na-based bentonite(Na-Bent).The factors affecting sodium-modification were investigated.The optimized experimental parameters are obtained as follows:Na2CO3 dosage 4.0%,ageing time 25 d,briquetting pressure 25 MPa and briquetting moisture 20%.Under the optimization conditions,the modified Na-Bent has a colloid value of 73.6 mL/(3g),dilation of 38 mL/g and water absorption in 2 h(2HWA) of 465%,respectively.The balling results indicate that the modified Na-Bent pellets have higher drop strength and compression strength than the Ca-Bent pellets.