Shih S M, Lin J P, Shiau G Y
Department of Chemical Engineering, National Taiwan University, 106, Taipei, Taiwan.
J Hazard Mater. 2000 Dec 1;79(1-2):159-71. doi: 10.1016/s0304-3894(00)00253-3.
The dissolution characteristics of limestones from six sources in Taiwan have been studied by using the pH-stat method in a stirred tank at 60 degrees C, pH values of 4 and 6, stirrer speeds of 500-1000 rpm, and a particle size of 75-125 microm aperture width. The dissolution rates of the limestones were found to be controlled by the mass transfer of hydrogen ions with chemical reactions in the liquid film surrounding the limestone particle. The measured value of mass transfer coefficient increases with an increasing pH value and stirrer speed and remains constant with particle size. For the six limestones at the same particle size, the measured dissolution rates per unit area are the same due to the mass-transfer control kinetics; however, the time taken to reach a certain fraction of dissolution is proportional to the molar concentration of the soluble species in the limestone and the initial particle size.
采用pH计法，在温度为60℃、pH值为4和6、搅拌速度为500 - 1000转/分钟、孔径宽度为75 - 125微米的搅拌槽中，研究了台湾六个产地的石灰石的溶解特性。发现石灰石的溶解速率受氢离子在石灰石颗粒周围液膜中的化学反应传质控制。传质系数的测量值随pH值和搅拌速度的增加而增大，与颗粒尺寸无关。对于相同粒径的六种石灰石，由于传质控制动力学，单位面积的测量溶解速率相同；然而，达到一定溶解分数所需的时间与石灰石中可溶物质的摩尔浓度和初始粒径成正比。
