Use of Porous no Metallic Minerals to Remove Heavy Metals, Precious Metals and Rare Earths, by Cationic Exchange

Abstract

This chapter is related with the preliminary study of some non-metallic minerals to evaluate their cationic exchange capacity, to remove heavy and precious metals, as well as rare earths elements. The minerals and materials used to execute the ion metals removal were bentonite, phosphorite, and diatomite. The chapter shows the physicochemical behavior of all these minerals, which were used to remove the mentioned elements from solutions coming from ore leaching. It was found that in all cases, the removal of heavy and precious metals, as well as rare earths elements reached over 90%. Although, there were minimal differences in efficiency for all minerals used (bentonite, phosphorite, and diatomite), it could be pointed that the phosphorite has the best results going from 99.43% of removal of Gd, to 99.95-100% for the case of Ce,

Ce and Nd Extraction by Cationic Exchange, Using Bentonite, Diatomite, and Eggshell—Preliminary Study

“…On the other hand, in this work, it was possible to corroborate the viability of ionic exchange between Ce and Nd with diatomite, bentonite, and eggshell. These results partially coincide with other studies [30,34,40]. The results obtained from the respective graphs show that there is a strong relationship between the change in the value of pH in the ion exchange experiment between diatomite and Ce and Nd; these results coincide with the tests of Sheng et al [33], which obtained similar results for the element thorium.…”

“…Additionally, in comparison with the maximum yield obtained by Anastopoulos et al, which was 16.6%, in this work, the maximum yield obtained from Ce was 98.36%. In the case of comparing the results of this work with those of Juan Hernández et al [34], it can be said that the results are similar since they also obtained yields above 99%. The best results for the cationic exchange found here were when using diatomite as the exchanger at all temperatures and a pH of 3 to obtain an extraction of Ce ranging from 98.13 to 99.06% and Nd ranging from 96.39 to 99.07%.…”

“…Additionally, also was carried out a preliminary study of cationic exchange using bentonite, phosphorite, and diatomite, finding that the best results were obtained with the phosphorite for the cationic exchange of precious metals and REE [34].…”

Perspective on the heavy metal pollution and recent remediation strategies

“…Diatoms can adapt well to environmental conditions, including biotic and abiotic stress ( Azimi et al., 2017 ). The use of diatoms is a novel approach that is cost-effective and eco-friendly ( Hernandez-Avila et al., 2019 ). As compared to other algae species, diatoms exhibit evolutionary variances in their cellular organization and metabolic pathways.…”