Effects of cations on rare earth adsorption and desorption in binding sites of montmorillonite

The exchangeability of rare earth (RE) in weathered crust elution-deposited ores largely depends on its interaction with clay minerals, which may be significantly influenced by various cations. Therefore, the effects K<sup>+</sup>, Ca<sup>2+</sup> and Al<sup>3+</sup> RE<sup>3+</sup> adsorption desorption binding sites montmorillonite (MMT) were investigated. Through pre-saturation, interlayer ions MMT had been replaced or Al<sup>3+</sup>. can adsorb Ca-MMT K-MMT, but nearly not Al-MMT. basal spacing is larger than provides a smaller hinder effect collapse for diffusion RE<sup>3+</sup>. capacity followed order: Ca-MMT＞K-MMT＞Al-MMT La<sup>3+</sup>＞Y<sup>3+</sup>＞Eu<sup>3+</sup>. It predict that grade exchangeable RE abundant most, ore rich K<sup>+</sup> least. Clay minerals tend to light hard middle heavy RE. reversibility adsorbed interlayers, especially collapsed far worse externals. rates order RE-Al-MMT＞RE-K-MMT＞RE-Ca-MMT Eu<sup>3+</sup>＞Y<sup>3+</sup>＞La<sup>3+</sup>. For RE<sup>3+</sup>, NH<sup>4+</sup> better Mg<sup>2+</sup> because change spacings (Δd) more minor activation energy barriers (ΔE) within interlayers. enrich metallogeny theory provide certain theoretical basis efficient exploitation.