Solubility of CaSO4 phases in aqueous HCl+CaCl2 solutions from 283 K to 353 K
Solubility of CaSO4 phases in aqueous HCl+CaCl2 solutions from 283 K to 353 K
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DOI：
10.1021/je050217e
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发表时间：
2005-11-01
期刊：
影响因子：
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通讯作者：
Demopoulos, GP
中科院分区：
文献类型：
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作者：
Li, ZB;Demopoulos, GP
在(283~353)K温度范围内，用经典等温溶解法测定了二水硫酸钙、半水硫酸钙和硬石膏在浓HCl、CaCl2及其混合水溶液中的溶解度。在室温下，HCl和CaCl2的浓度分别为12mol.dm(-3)和3.5moldm(-3)。除了硬石膏在CaCl2溶液中的溶解度外，所有被考察的情况下CaSO4相的溶解度都随温度升高而增加。在纯HCl介质中，在(0.0~3)mol(·dm(-3))HCl范围内增加酸浓度，CaSO(4)(·)2H2O或CaSO4的溶解度增大，达到最大值，然后随HCl浓度的增加而逐渐减小。在(8~12)mol(.)dm(-3)HCl浓度范围内，CaSO4.1/2H2O的溶解度随酸浓度的增加而减小。在HCl+CaCl2混合介质中，由于共同离子效应，CaCl2的加入使三相的溶解度明显降低。
Solubilities of calcium sulfate dihydrate, hemihydrate, and anhydrite in concentrated HCl, CaCl2, and their mixed aqueous solutions were measured by using the classic isothermal dissolution method at the temperature range from (283 to 353) K. The concentration investigated for HCl is up to 12 mol(.)dm(-3) and for CaCl2 is up to 3.5 mol(.)dm(-3) at room temperature. The solubility of CaSO4 phases in all cases investigated was found to increase with the temperature increment with the exception of anhydrite in CaCl2 solutions. In pure HCl media, increasing the acid concentration in the range of (0.0 to 3) mol(.)dm(-3) HCl causes the solubility of CaSO(4)(.)2H(2)O or CaSO4 to increase reaching a maximum value and then decrease gradually with further increasing HCl concentration. In the concentrated range of (8 to 12) mol(.)dm(-3) HCl, the solubility of CaSO4.1/2H2O decreases with acid concentration. In HCl + CaCl2 mixed media, the addition of CaCl2 causes the solubility of all three phases to decrease due apparently to common ion effect.