Showing 5 results for Azizi
R. Katal, A. Azizi, M. Gharabaghi,
Volume 17, Issue 2 (June 2020)
Abstract
Present paper investigates the dissolution behavior of copper from chalcopyrite concentrate sample using cupric chloride solution in detail. Response surface modeling (RSM) in combination with d-optimal design (DOD) was utilized for modeling and optimizing the cupric chloride leaching process. At first, a quadratic polynomial model was developed for the relationship between the recovery of copper and influential factors. The predictions indicated an excellent agreement with the experimental data (with R2 of 0.9399). Then, the effects of main factors including pH (1-4), liquid/solid ratio (2-7 mL/g), temperature (70-90 °C), CuCl2 concentration (6-35 g/L), and leaching time (0.5-16) were determined. The findings demonstrated that the temperature and CuCl2 concentration were the most effective factors on the dissolution rate of copper from chalcopyrite sample, while liquid/solid ratio had the lowest impact. The recovery of copper increased linearly with an increment in the liquid/solid ratio and the decrease in the pulp pH. Additionally, the recovery enhanced by increasing the temperature and CuCl2 concentration owing the generation of Cu–Cl complexes species and reached a plateau point and then almost remained unchanged. Meanwhile, it was found out that the recovery of copper was independent of the interaction between factors. Moreover, the optimization of leaching process was carried out by Design Expert (version 7) software and desirability function method and the highest recovery of copper was found to be about 86.1% at a pH of ~1.4, temperature of 89 °C, liquid/solid ratio of 6.8 mL/g, CuCl2 concentration of 21.79 g/L and leaching time of ~8 h.
Nur Mohammad Hosseini, Zahra Bahri, Asghar Azizi,
Volume 19, Issue 4 (Desember 2022)
Abstract
The beneficiation of coal tailings is usually difficult by common oily collectors in the flotation process, so
it is necessary to use a suitable method for clean coal recovery from coal tailing dams. Thus, this study was aimed
to investigate the behavior of dissolved air flotation by zero prewetting time for the clean coal recovery and to
optimize the conditions of zero prewetting time for an effective flotation. In this regards, the effects of the process
parameters, i.e., pH, frother type, collector type on the rougher flotation recovery of coal tailings were assessed and
optimized. Additionally, Fourier transform infrared (FTIR) spectroscopy was used to understand the functional
groups of oily collectors on the surface of floated products. The findings indicated that the frother type and the
interactive effects between the type of frother and collector had the most effect on the performance of flotation. It
was also found that under the optimal conditions (150 g/t Methyl isobutyl carbinol, 1500 g/t gas oil, and pH 4), the
combustible recovery, yield reduction factor, and flotation efficiency index of coal reached to 67.79%, 0.056%, and
37%, respectively. Meanwhile, the FTIR analysis confirmed that the less adsorption of gas oil collector occurred in
the presence of SDS (Sodium dodecyl sulfate) as frother due to the interaction of SDS and collectors
