The utilization of Ca ion as assistant depressant of CMC on talc has been widely reported. Thus, the study on the adsorption mechanism of Ca ion on talc surface is very crucial for understanding the performance of CMC on talc depression. In this paper, mechanism insights into hydrated Ca ion adsorption on talc (0 0 1) basal surface were creatively provided using DFT calculation. [Ca(H₂O)₆]²⁺ and [Ca(OH)(H₂O)₃]⁺ were determined as the effective hydrate components for Ca ion adsorption, and the top O site was the most favorable position for their adsorptions on talc surface. Furthermore, the adsorption mechanisms of [Ca(H₂O)₆]²⁺ and [Ca(OH)(H₂O)₃]⁺ on talc surface were found to be not the Ca—O chemical bond, but the hydrogen bonding formed by the H atom of the H₂O ligand and the surface O atom. H₂O acted like a bridge to connect them to the talc surface. Moreover, the hydrogen bonding was formed due to the hybridization of H 1s orbital with the O 2s, O 2p orbitals. Simultaneously, electrons transferred between the H atom and the surface O atom. This work provides theoretical insights into the Ca ion adsorption on talc surface, which can help deeply understand the talc flotation using CMC as depression.

钙离子作为滑石粉上 CMC 的辅助抑制剂已被广泛报道。因此，研究钙离子在滑石表面的吸附机理对于了解CMC对滑石抑制的性能至关重要。 本文利用DFT计算创造性地提供了滑石（0 0  1）基面水合Ca离子吸附的机理见解。[Ca(H ₂ O) ₆ ] ²⁺和[Ca(OH)(H ₂ O) ₃ ] ⁺被确定为对Ca离子吸附的有效水合物组分，顶部O位是其吸附最有利的位置在滑石表面上。此外，[Ca(H ₂ O)₆ ] ²⁺和[Ca(OH)(H ₂ O) ₃ ] ⁺发现滑石表面不是Ca-O化学键，而是H ₂ O配体的H原子与表面O原子。H ₂ O 就像一座桥梁，将它们连接到滑石表面。此外，氢键是由于H 1s 轨道与O 2s、O 2p 轨道的杂化而形成的。同时，电子在 H 原子和表面 O 原子之间转移。该工作为滑石表面钙离子吸附提供了理论见解，有助于深入了解以CMC为凹陷的滑石浮选。