Calcium Carbonate Dissolution Rate in Limestone Contactors
Calcium Carbonate Dissolution Rate in Limestone Contactors
复制标题
石灰石接触器中的碳酸钙溶解率
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
R. Letterman
中科院分区：
文献类型：
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作者：
R. Letterman
本项目总结了用于预测石灰石接触器性能的一些参数和关系。该项目的目的是研究石灰石组成，特别是白云石[CaMg(CO 3) 2]和石中杂质含量对碳酸盐矿物溶解动力学的影响，并确定温度对溶解速率的影响。溶解速度是用旋转圆盘装置和不同成分的石灰石样品测定的。石灰石样本包括白色大理石和精选的沉积岩。白色大理石含有大量的二氧化硅（约35%）。沉积石灰岩的主要矿物成分从大约100%的方解石（caco3）到基本上纯白云石不等。石头的铁（Fe）含量约为15至377 mg Fe/100g，铝（Al）含量约为1至134 mg Al/100g。矿物溶解的非均相反应模型有效地解释了除白云石含量最高的两个样品外所有样品的旋转盘实验结果。随着方解石含量从0.92 g caco3 /g下降到0.09 g caco3 /g，新石的溶解速率常数下降了约60%。白云石含量高的石头的溶解速度可能因少量钙石的存在而加快。除了白云石含量最高的两个样品（93%和100%白云石）外，所有样品的镁（Mg）的增溶率都可以忽略不计。总溶解速率常数随着石表面钙溶解量的增加而减小。在单位面积石材表面钙溶解量一定的情况下，随着石材中铁、铝含量的增加，溶解率常数百分比下降幅度增大。当石中铁铝含量加权和小于10 mg/g时，样品老化对溶蚀速率的影响最小。加权和等于Al/g中铝的含量加上Fe/g中铁的含量的0.30倍。二氧化硅作为白色大理石中主要杂质的存在，似乎与样品中二氧化硅的质量成比例地减少了石头的有效（钙石）表面积，但是……
The project summarized here investigated some of the parameters and relationships used to predict the performance of limestone contactors. The purpose of the project was to study the effect of limestone composition, especially the dolomite [CaMg(CO 3) 2 ] and impurity content of the stone, on the kinetics of carbonate mineral dissolution and to determine the effect of temperature on the rate of dissolution. The rate of dissolution was determined by using a rotating disk apparatus and samples of limestone of varied composition. The limestone samples included a white marble and a selection of sedi-mentary stones. The white marble contained a significant amount of silica (approximately 35%). The major mineral constituents of the sedimentary limestones ranged from approximately 100% calcite (CaCO 3) to essentially pure dolomite. The approximate iron (Fe) content of the stones ranged from 15 to 377 mg Fe/100g and the approximate aluminum content (Al) from 1 to 134 mg Al/100g. A heterogeneous reaction model for mineral dissolution effectively explained the results of the rotating disk experiments for all samples except the two with the highest dolomite content. The magnitude of the dissolution rate constant for fresh stone decreased by approximately 60% as the calcite content of the stone decreased from 0.92 to 0.09 g CaCO 3 /g stone. The rate of dissolution of stones with a high dolomite content may have been enhanced by the presence of small amounts of cal-cite. The rate of solubilization of magnesium (Mg) was negligible in all samples except the two with the highest dolomite content (93 and 100 mass percent dolomite). The overall dissolution rate constant decreased as the amount of calcium dissolved from the surface of the stone increased. For a given amount of calcium dissolved per unit area of stone surface, the magnitude of the percentage decrease in the dissolution rate constant increased as the iron and aluminum content of the stone increased. The effect of sample aging on the rate of dissolution was lowest when the weighted sum of the iron and aluminum content of the stone was less than about 10 mg/g. The weighted sum is equal to the aluminum content in mg Al/g plus 0.30 times the iron content in mg Fe/g. The presence of silica as the principal impurity in the white marble seemed to reduce the effective (cal-cite) surface area of the stone in proportion to the mass of silica in the sample, but …