通过改变固液比、摇床转速、珊瑚砂粒径、温度、溶液pH值及溶液含盐量等参数,对珊瑚砂在水溶液中溶出Ca2+、Mg2++进行了实验,以探讨溶出过程中的动力学规律和影响因素.实验结果表明,珊瑚砂中Ca2+、M2++溶出量随反应时间逐渐增大;摇床转速越快、固液比越大、温度越高、溶液pH值越低,Ca2+、M2++溶出量越大;当珊瑚砂粒径为2.36～4.75 mm、溶液含盐量为100 mg/L时,Ca2+、M2++溶出量最大.统计分析表明,摇床转速、温度及溶液pH值均对珊瑚砂溶出有显著影响,但溶液pH值影响最大.珊瑚砂在水中的溶出过程符合收缩核内扩散模型,表明控制整个溶出过程反应速率的决定因素是内扩散速率;在15～40℃时,珊瑚砂在纯水中溶出Ca2+、M2+的活化能分别为78.07和74.91 kJ/mol.%In order to discuss and determine the dissolution kinetics law and influence factors of the dissolution of Ca2 + and Mg2 + in coral sand,the authors conducted dissolution experiments of Ca2 + and Mg2 + in aqueous solution under different conditions of the solid-liquid ratio,the rotational speed of the shaker,the particle size of coral sand,the temperature,the pH value,and the salt content of the solution.The results show that Ca2 + and Mg2+ dissolution in coral sand gradually increased with the reaction time,and the higher the speed,solid-liquid ratio and temperature,the greater the dissolution of Ca2 + and Mg2 +,and the lower pH value is beneficial to the dissolution of Ca2+ and Mg2+.When particle size of coral sand is 2.36～4.75 mm,and the salt content is 100 mg/L,the dissolution amount of Ca2+ and Mg2 + reaches the maximum.The statistical analysis shows that the rotational speed,temperature and solution pH have significant influence on the dissolution of coral sand,whereas the pH value among them seems to be the greatest influence factor.Kinetic studies show that the dissolution of coral sand in water is consistent with the internal diffusion model of shrinking nuclei,which suggests that internal diffusion rate is the decisive factor controlling the dissolution reaction.In addition,from 15℃ to 40℃,the dissolution activation energy of Ca2+ and Mg2+ in coral sand is 78.07 kJ/mol and 74.91 kJ/mol respectively.
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