The depression behavior and mechanism of tragacanth gum on chalcopyrite during Cu-Mo flotation separation

Mechanism of Cu Ion Targeting Combined with an Organic Depressant To Enhance the Flotation Depression of Pyrite

In this study, pyrite was used as the research object, and the behavior and mechanism of a copper-ion-enhanced organic depressant in depressing pyrite flotation were studied. Microflotation experiments showed that, after the addition of CuSO4 and N,N-dimethyldithiocarbamate (N,N-DDS), the floating collection efficiency of pyrite declined from 82.37 to 21.03% at pH 8.5. Infrared spectroscopy studies indicated that the addition of CuSO4 caused a significant enhancement in the characteristic N,N-DDS peaks on the pyrite surface. X-ray photoelectron spectroscopy (XPS) revealed that, following the addition of CuSO4 and N,N-DDS, the relative atomic concentration of N 1s considerably enhanced on the surface of pyrite, with N 1s derived from N,N-DDS. Time-of-flight secondary ion mass spectrometry showed that, before and after the addition of CuSO4, the normalized peak values of CSN- on the pyrite superficial layer were 0.0116 and 0.0032, respectively. All of the above-mentioned results indicate that the Cu ion promotes the adsorption of N,N-DDS on pyrite and facilitates the formation of complex ((CH3)2NCSS)2Cu. The N and S atoms in -NCS and metal ions formed chemical bonds, which were the primary mechanism of the interaction between N,N-DDS and pyrite. This process reduces the floatability of pyrite and achieves the selective depression of pyrite.

Pullulan Polysaccharide as an Eco-Friendly Depressant for Flotation Separation of Chalcopyrite and Molybdenite

It is difficult to separate molybdenite and chalcopyrite by froth flotation due to the good floatability of the two minerals. In this paper, the separation of copper-molybdenum sulfide minerals was realized by using pullulan polysaccharide (PU) as the depressant. The flotation test results showed that the copper concentrate grade increased from 16.24 to 29.86%, and the copper concentrate recovery reached 83.55% under low alkali conditions. The selective separation mechanism of the two minerals by PU was revealed through contact angle measurements, ζ-potential measurements, Fourier transform infrared (FTIR) spectroscopy analyses, and X-ray photoelectron spectroscopy (XPS) analyses. The ζ-potential and contact angle results showed that PU is more easily adsorbed on molybdenite to strengthen the hydrophilicity of molybdenite. The FTIR and XPS results showed that PU is adsorbed on molybdenite by physical interactions, and hydrophobic interactions and hydrogen bonding play a major role.