pH值对脱硫石膏晶须生长行为的影响

以脱硫石膏为原料，采用水热法制备CaSO4晶须. 借助电导率、SEM和XRD、高分辨显微镜等分析方法，研究了不同pH值下CaSO4晶须的生长规律. 结果表明，随着pH值增加，CaSO4晶须的长径比呈先升高后降低的趋势，初始pH值为5时，晶须的直径为1~4 mm，平均长度为218.67 mm，长径比达最大，为82.57. pH值直接影响杂质的存在状态，随pH值增加，杂质中的SiO2逐渐转变为CaSiO3，并使溶液中的离子平衡发生变化，从而影响晶须在某一方向的生长趋势.

Effect of pH Value on Growth of Desulphurization Gypsum Whiskers

Using desulphurization gypsum as raw material, hydrothermal method was applied to prepare calcium sulfate whiskers and using conductivity, SEM, XRD and high resolution microscope as analysis methods, the growth principle of calcium sulfate under different pH values was explored. The results reveal that with the increase of pH value, the aspect ratio of calcium sulfate whiskers firstly increased and then decreased. When the pH value was 5, the whisker diameter was 1～4 μm, the average length 218.67 μm and the aspect ratio reached the maximum value of 82.57. The change of pH value exerted a direct influence on the existence of impurities, with the increase of pH, SiO_2 within the impurities gradually transformed into CaSiO_3, and the equilibrium of ions in the solution changed and hence affected the growth tendency of the whiskers in a specific direction.