Ammonia stripping of fly ash slurry and its paste preparation characteristics
In order to improve the adverse effects of ammonia-containing fly ash on the performance of filling paste and improve the utilization rate of fly ash,the air stripping of fly ash slurry was used to remove ammonia in the experiment.The effects of stripping time,air-slurry ratio,solid-liquid ratio,temperature and alkali addition on the ammonia removal rate of fly ash were investigated.The results showed that the stripping conditions were optimized by response surface methodology,and the stripping time was 1h,the gas-slurry ratio was 900,the solid-liquid ratio was 0.219,the temperature was 26.785℃ and the alkali dosage was 1.802%.The predicted total ammonia removal rate was up to 97.178%,and the actual error rate was within 2%.The fly ash filling paste prepared after optimized stripping has only a small amount of ammonia release in the early stage of curing,and its pumping performance and microstructure are improved compared with the original ammonia-containing fly ash paste.After 28days of curing,the compressive strength is increased by up to 57%.
万方数据
维普
