Niobium (Nb) in kaolin clay usually occurs in the Ti-bearing minerals, such as rutile and anatase. However, the low Ti-bearing minerals contents for some kaolin clay rocks were insufficient to explain the high Nb concen-trations. Thus, Nb was widely considered to be adsorbed by clay minerals. However, the adsorption behavior of niobium (V) on clay minerals has not been fully understood. In this study, a series of batch adsorption experi-ments were carried out on kaolin clay (Kclay) and pure kaolinite (Kaol) using niobium oxalate solutions. The effects of contact time, initial niobium (V) concentration, solution pH, and temperature on the adsorption were investigated. The results showed that Kclay exhibited a higher adsorption capacity than Kaol under the same conditions. The niobium (V) adsorptions on Kclay and Kaol were pH-dependent, and both of them showed declining adsorption capacities from pH 2 to 4. The adsorption behaviors of niobium (V) on Kclay and Kaol conformed to the pseudo-second-order model. The adsorption isotherm of Kclay was a better fit with the Freundlich isotherm model, while the Langmuir isotherm model was a better fit for Kaol. The Langmuir maximum adsorption amount of Kclay and Kaol were 5.42 and 2.25 mg/g, respectively. These results demon-strated that niobium (V) can be adsorbed by kaolin clay and kaolinite.
Publication name |
Applied Clay Science, Volume 235, Article Number 106866, DOI 10.1016/j.clay.2023.106866, Published APR 2023, Early Access FEB 2023 |
Author(s) |
Yang, Tingting; Wang, Ning; Gu, Hannian |
Corresponding author(s) |
Gu, Hannian guhannian@vip.gyig.ac.cn 99 Lincheng West Rd, Guiyang City 550081, Guizhou Provinc, Peoples R China |
Author(s) from IGCAS |
Gu, Hannian; Yang, Tingting; Wang, Ning | View here for the details
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