ACIDIZATION .2. DISSOLUTION OF CALCITE IN HYDROCHLORIC-ACID
ACIDIZATION .2. DISSOLUTION OF CALCITE IN HYDROCHLORIC-ACID
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DOI：
10.1016/0009-2509(75)80047-9
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发表时间：
1975-01-01
影响因子：
4.7
通讯作者：
AULT, JW
中科院分区：
文献类型：
--
作者：
LUND, K;FOGLER, HS;AULT, JW
研究了方解石在- 15.6 - 25℃的温度下，在800 psig的旋转圆盘系统下在盐酸中的溶解。在25°C时，溶出过程受传质限制，即使在高圆盘转速下也是如此，而在- 15.6°C时，传质和表面反应速率都限制了溶出速度。用电化学电位梯度作为扩散驱动力，定义了反应物和生成物的多组分耦合离子扩散通量。根据哈内德规则，计算了扩散物质的多组分扩散系数。通过对耦合对流扩散方程组进行数值积分，确定了边界层中离子的浓度分布。考虑了变密度、粘度和高质量通量对边界层流体速度的影响。表面反应速率与表面盐酸浓度的0·63次方成正比。实验分析表明，氢离子在固体方解石表面吸附（用Freundlich吸附等温线描述），吸附后的氢离子与固体方解石基体发生反应是反应机理。
The dissolution of calcite in hydrochloric acid was studied with the aid of a rotating disk system at 800 psig in the temperature range −15·6–25°C. At 25°C the dissolution process is mass transfer limited even at high disk rotation speeds whereas at −15·6°C both mass transfer and surface reaction rates limit the dissolution rate. The multicomponent coupled ionic diffusive fluxes of reactants and products were defined by using the gradient of the electrochemical potentials as driving forces for the diffusion. The activity coefficients used in calculating the multicomponent diffusivities of the diffusing species were estimated by Harned's rule. The concentration profiles of the ions in the boundary layer were then determined by numerically integrating the system of coupled convective diffusion equations. The effects of variable density, viscosity, and high mass fluxes on the fluid velocity in the boundary layer were taken into account. The rate of the surface reaction was found to be proportional to the 0·63 power of the surface hydrochloric acid concentration. Analysis of the experiments suggests that the absorption of hydrogen ion (described by a Freundlich adsorption isotherm) on the solid calcite surface and subsequent reaction of the adsorbed hydrogen ion with the solid calcite matrix is the reaction mechanism.