The application and mechanism of high-efficiency depressant Na2ATP on the selective separation of cassiterite from fluorite by direct flotation

To achieve the efficient flotation separation of cassiterite from fluorite, an eco-friendly depressant, the disodium salt of adenosine 5'-triphosphate (Na(2)ATP), was employed for the selective depression of fluorite. The performance of Na(2)ATP as a depressant in the flotation of cassiterite and fluorite was evaluated by micro-flotation experiments in a sodium oleate (NaOL) system. The flotation tests revealed that Na(2)ATP significantly depressed the flotation of fluorite compared to that of cassiterite, and excellent separation was achieved using 1.0 mM Na(2)ATP and 0.14 mM NaOL at pH 8.02. Moreover, the mechanism of the selective depression Na(2)ATP on the two minerals was revealed by surface analyses, revealing that chemisorption between the phosphate group of Na(2)ATP and the calcium ions on the fluorite surface was responsible for the selective adsorption of Na(2)ATP on fluorite, and the significant pre-adsorption of Na(2)ATP onto the fluorite surface impeded the further adsorption of NaOL. However, because Na(2)ATP was adsorbed on cassiterite by physisorption, which is relatively weak, the strong chemisorption of NaOL on cassiterite occurred regardless of pre-treatment with Na(2)ATP. Furthermore, density functional theory calculations revealed that the adsorption mode of Na(2)ATP to be horizontal and to occur at multiple calcium-ion sites on the fluorite surface. In summary, Na(2)ATP is a suitable high-efficiency depressant for the separation of cassiterite from fluorite by direct flotation.

Automated summary

In order to achieve efficient flotation separation of cassiterite from fluorite, a eco-friendly depressant, Na(2)ATP, was used to selectively depress fluorite. Micro-flotation experiments showed that Na(2)ATP significantly depressed the flotation of fluorite compared to cassiterite, and the mechanism of selective depression was revealed through surface analyses. Na(2)ATP proved to be a suitable high-efficiency depressant for the separation of cassiterite from fluorite by direct flotation.