Investigations of amino trimethylene phosphonic acid as a green and efficient depressant for the flotation separation of apatite from calcite

• Published in: Minerals engineering 2022-05, Vol.181, p.107552, Article 107552
• Main Authors: Liu, Cheng, Zhu, Lei, Fu, Weng, Chi, Ruan, Li, Hongqiang, Yang, Siyuan
• Format: Article
• Language: English
• Subjects: Adsorption mechanism; Apatite; ATMP; Calcite; Flotation separation; NaOl
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2022.107552

The selective depression ability of calcite was attributed to the reason that the CaCa distances of calcite match well with the OO distances at two functional groups of ATMP, but the CaCa distance of apatite can only fit with the OO distance at POH groups of ATMP. [Display omitted] •ATMP was utilized as a novel depressant for calcite in the apatite flotation.•The efficient separation of calcite and apatite could be achieved using NaOl/ATMP.•ATMP could interact with the calcium ion of calcite via chemisorption.•The electrostatic repulsion and steric resistance existed between ATMP and apatite.•The stable adsorption between ATMP and apatite is caused by molecular geometry matching. Flotation separation of apatite from calcite is difficult due to their same activate calcium atoms on the surface. To address this issue, amino trimethylene phosphonic acid (ATMP) was introduced to separate apatite and calcite in this research. The microflotation results showed that NaOl had an excellent collecting ability to apatite and calcite. Meanwhile, the tests also found that ATMP had a strong depression ability to calcite, but it hardly influenced the apatite floatability. The artificial mixed minerals flotation results confirmed that ATMP could be used as a depressant to separate apatite and calcite in the presence of NaOl. Zeta potential measurements illustrated that the addition of ATMP prevented the NaOl adsorption onto the calcite surface, while it hardly affected the interaction of NaOl with the apatite surface. Solution chemistry calculation of ATMP was conducted to reveal the main species of ATMP, while XPS analysis further indicated the strong chemisorption of ATMP onto calcite rather than apatite. Hence, the selective depression ability of ATMP was attributed to the electrostatic repulsion and steric resistance for the apatite surface and the stable adsorption structure at the calcite surface.