Interaction of NH3·H2O – 2,5-Dimercapto-1,3,4-thiadiazole system with azurite surface and its role in promoting activation flotation.

[Display omitted] • NH 3 ·H 2 O–DMTD system has stronger activation effect on azurite than single DMTD. • NH 3 ·H 2 O–DMTD system mitigates azurite-flotation inhibition at high DMTD dosage. • The activity and stability of azurite surface product were markedly enhanced. • The colloidal content of Cu(I)-DMTD in the flotation solution was reduced. Azurite is an important alkaline copper carbonate mineral, and its efficient activation is important for improving the recovery of copper oxide minerals. 2,5-Dimercapto-1,3,4-thiadiazole (DMTD) is an excellent activator of azurite within a narrow dosage range but severely inhibits azurite flotation at high dosages. In practical industrial applications, precisely controlling the activator dosage is challenging. Herein, the effects of a new NH 3 ·H 2 O–DMTD activation system on the floatability and flotation interface characteristics of azurite were compared with those of a conventional single DMTD. The morphological evolutions, chemical compositions, and states of the azurite surface activation products were studied using X-ray photoelectron spectroscopy and field-emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The variation trends of the flotation solution components were determined using inductively coupled plasma–optical emission spectroscopy and ultraviolet–visible spectroscopy. Furthermore, the adsorption strength of a xanthate collector was characterized using time-of-flight secondary ion-mass spectrometry. Results show that the NH 3 ·H 2 O–DMTD system considerably strengthens the activation effect of DMTD on azurite, prevents flotation inhibition at high DMTD dosages, and effectively expands the optimal dosage range of DMTD. [ABSTRACT FROM AUTHOR]