Dissolution kinetics of malachite in ethylene diamine phosphate solutions

Ethylene diamine phosphate (EDP), as a synthetic organic reagent, was used for the first time to leach malachite, and a new method of using organic amine to leach copper oxide ore was developed. The effects of stirring speed, particle size, reagent concentration, and reaction temperature on EDP-dissolution malachite were investigated. Results showed that malachite rapidly dissolved in EDP solution. The malachite-dissolving rate also increased with increased reagent concentration, increased reaction temperature, and decreased particle size. Stirring speed exhibited nearly no effect on EDP-induced malachite dissolution. The leaching kinetics was found to follow the shrinking-core model, and dissolution was controlled by surface chemical reaction with an activation energy of 52.63kJ×mol−1. A semiempirical rate equation was obtained to describe the dissolution process expressed as 1-(1-XCu)1/3=0.0149(CEDP)0.7814 × (Pmalachite)−0.7982×exp(−6.3308/T) ×t

Effect of Ammonium Sulfide on Sulfidization Flotation of Malachite

Recently, several studies have shown the positive effect of sulfidization flotation on malachite surfaces and its enhancing methods. Therefore, this paper was focused on the effect of ammonium sulfide and sodium sulfide on the sulfidization of malachite, respectively; this was investigated using different devices such as the micro-flotation tests, Zeta potential measurements, ToF–SIMS, XPS analysis, and FTIR. Thus, Fourier transform infrared spectroscopy results demonstrated that a new characteristic peak of Cu-S bonds was formed and adsorbed on malachite surfaces at 1694 cm−1, as confirmed by XPS analysis. Notably, malachite with ammonium sulfide ions had a significantly higher flotation recovery than malachite with an excess of sodium sulfide ions, as concerns of sulfidization types. Conclusively, all the experiments in this study confirmed that additional copper sulfide products were formed on the malachite surface, increasing the hydrophobicity of the malachite

Effect of Ammonium Sulfide on Sulfidization Flotation of Malachite

Recently, several studies have shown the positive effect of sulfidization flotation on malachite surfaces and its enhancing methods. Therefore, this paper was focused on the effect of ammonium sulfide and sodium sulfide on the sulfidization of malachite, respectively; this was investigated using different devices such as the micro-flotation tests, Zeta potential measurements, ToF–SIMS, XPS analysis, and FTIR. Thus, Fourier transform infrared spectroscopy results demonstrated that a new characteristic peak of Cu-S bonds was formed and adsorbed on malachite surfaces at 1694 cm−1, as confirmed by XPS analysis. Notably, malachite with ammonium sulfide ions had a significantly higher flotation recovery than malachite with an excess of sodium sulfide ions, as concerns of sulfidization types. Conclusively, all the experiments in this study confirmed that additional copper sulfide products were formed on the malachite surface, increasing the hydrophobicity of the malachite

Effect of Ethylene Diamine Phosphate on the Sulfidization Flotation of Chrysocolla

In this study, ethylene diamine phosphate (EDP) was employed as an activator to improve the sulfidization and flotation of chrysocolla. The micro-flotation experiment results indicated that EDP could greatly increase the flotation recovery of chrysocolla. BET and TEM measurements confirmed that the porous structure of the chrysocolla’s surface would lead to large amounts of the reagents. ICP-AES analysis revealed that the addition of EDP caused more active Cu sites formed on the chrysocolla’s surface, enhancing the adsorption of S2− on its surface. Meanwhile, a redox reaction occurred between the S2− and [Cu(en)2]2+ ions causing the Cu, S, and N in the solution to counter-adsorb onto the chrysocolla’s surface by forming new complexes. During this reaction, the Cu(II) species reduced to Cu(I) species and the sulfide ions in the form of S2−, S22−, Sn2−, and SO42− appeared on the mineral surface. The zeta potential measurements further revealed that the EDP-activated chrysocolla surfaces adsorbed more sulfide species and xanthate species, thereby improving the floatability of the chrysocolla

Role of ammonium phosphate in improving the physical characteristics of malachite sulfidation flotation

In this study, ammonium phosphate ((NH4)3PO4) was employed to realize improvement by modifying the physical characteristics of the malachite surface, ensuring sustainable flotation throughout the flotation operations, and enhancing the flotation process to be more stable. Furthermore, various techniques, including X-ray photoelectron spectroscopy, were intensely used to investigate the configuration and physico-chemical surface characteristics through micro-flotation experiments, contact angle and zeta potential measurements, and XRD, ToF-SIMS, EPMA, and FTIR spectrum analyses. The FTIR findings showed that new characteristic peaks of -C(=S)-N.H. groups formed and adsorbed on the surfaces of malachite at 1636 cm-1. The -CH2 groups throughout the flotation process, further promoted the attachment of the CH3 ligand to the Cu2+ ion, and the XPS analysis confirmed this. Consequently, it can be concluded that (NH4)3PO4 played a substantial part in the improved recovery rate, as demonstrated and confirmed by the methods carried out in this study. Thus, it was used to modify the physical properties surface before adding Na2S to efficiently enhance malachite floatability and reduce the loss rate of malachite. Regarding the alterations in the physical characteristics which occurred to the malachite surface, and as a consequence of increasing the recovery results of flotation, the malachite sample treated initially with (NH4)3PO4 exhibited micro flotation results with a considerably greater flotation recovery than malachite treated initially with only Na2S ions