Study on the Adsorption Characteristics of Kaolin Blended with Different Proportions of NaCl under High-Temperature Conditions.

Zhundong coal is characterized by its high alkali metal content, which can easily lead to slagging and scaling on the heating surfaces of the boiler during combustion. In practical applications, the blending of kaolin is commonly adopted to mitigate these slagging and fouling issues during the combustion of Zhundong coal. This study uses a three-stage, high-temperature drop tube furnace. It selects blending ratios of 0%, 2%, 4%, and 6% to investigate the effects of kaolin blended with different proportions of NaCl on alkali metal adsorption and fine particle formation characteristics. The results showed that as the NaCl blending ratio increased, the peak concentration of particulate matter gradually rose by 542.69 mg/Nm. With the increase of the blending ratio from 2% to 6%, the content of Na in PM rose from 3.79% to 6.79%, and the content of Na in PM increased from 3.77% to 4.85%. The particle morphology became more regular, smooth, and uniform. Kaolin can react chemically with sodium chloride to form a stable aluminum silicate, which can effectively adsorb sodium vapors.