提氨脱硫石膏作水泥缓凝剂的试验研究

Experimental research on ammonia extraction desulfurization gypsum as cement retarder

捉氨脱硫石膏是制备镍钴锰(NCM)三元材料前驱体时处理回收洗涤废液产生的固体废弃物,其主要物相为二水石膏,但将其作水泥缓凝剂使用过程中会造成水泥强度较大波动。通过试验分析排查出造成水泥强度波动的原因与其含有一定的絮凝剂聚丙烯酰胺(PAM)有关,将水泥中聚丙烯酰胺的有效含量控制在0.1%以内则对水泥强度无负面影响,而提高提氨脱硫石膏中PAM的水解与盐解程度可降低其对水泥强度的不利影响。

Ammonia extraction desulfurization gypsum is a solid waste produced during the treatment and recovery of washing waste liquid when preparing the precursor of nickel cobalt manganese(NCM)ternary material.Its main phase is gypsum dihydrate.However,when it was used as cement retarder,the cement strength would fluctuate greatly.It was found that the reason of cement strength fluctuation was related to the presence of certain flocculant polyacrylamide(PAM).If the effective content of polyacrylamide in cement was controlled within 0.1%o,there would be no negative impact on cement strength.Moreover,increasing the hydrolysis and salting hydrolysis degree of PAM in ammonia extraction desulfurization gypsum can reduce its adverse impact on cement strength.