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pressure-leaching
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Pressure leaching of chalcopyrite concentrate with oxygen and kinetic study on the process in sulfuric acid solution
, Article Transactions of the Indian Institute of Metals ; Volume 73, Issue 4 , 6 March , 2020 , Pages 975-987 ; Rasouli, S ; Yoozbashizadeh, H ; Sharif University of Technology
Springer
2020
Abstract
In this research work, the pressure leaching of chalcopyrite concentrate with oxygen was studied. Experiments were carried out under conditions of the solid–liquid ratio of 0.1, agitation speed of 750 rpm, and sulfuric acid concentration of 2 M in a stainless-steel autoclave system under 0.6 to 1 MPa oxygen gas. Central composite design was used to design experiments, and three factors of temperature, time, and oxygen pressure were selected as the design variables. A linear model for %Cu and a quadratic model for %Fe were proposed by Minitab Software. The results showed that temperature is the most effective factor in chalcopyrite leaching. Under optimal conditions, 93.08% of copper with the...
Determination of optimal conditions for pressure oxidative leaching of sarcheshmeh molybdenite concentrate using Taguchi method
, Article Journal of Mining and Metallurgy, Section B: Metallurgy ; Volume 48, Issue 1 , 2012 , Pages 89-99 ; 14505339 (ISSN) ; Yoozbashizadeh, H ; Sharif University of Technology
2012
Abstract
The present research work is based on finding the optimum conditions for pressure oxidative leaching of the molybdenite concentrate to produce technical-grade molybdic oxide (MoO 3) with high recovery through further treatment of the filtrate solution. The Taguchi method was used to design and minimize the number of experiments. By using Taguchi orthogonal (L 25) array, five parameters (time, temperature, oxygen pressure, pulp density and acid concentration) at five levels were selected for 25 experiments. The experiments were designed and carried out in a high-pressure reactor in the presence of nitric acid as solvent and oxidizing agent for the molybdenite concentrate and its ReS 2...
Optimization of Pressure Leaching of Chalcopyrite Concentrate with Oxygen and Kinetics Study of the Process in Sulfuric Acid Solution
, M.Sc. Thesis Sharif University of Technology ; Yoozbashizadeh, Hossein (Supervisor)
Abstract
The enormous benefits of hydrometallurgical processes have led to the progressive metals extraction industry. Many studies are carried out on the application of these processes in the copper extraction industry. In this research, the oxygen pressure leaching of chalcopyrite concentrate was studied. Experiments were carried out under conditions of the solid-liquid ratio of 0.1, agitation speed of 750 rpm, and sulfuric acid concentration of 2M in a stainless-steel autoclave system. Central composite design (CCD) was used to design experiments, and three factors of temperature, time, and pressure of oxygen, were selected as design variables. The obtained model for %Cu includes parameters of...
Optimization of the Solvent Extraction of Rhenium from Acidic Solution Produced by Pressure Leaching of Molybdenite Concentrate
, M.Sc. Thesis Sharif University of Technology ; Yoozbashizadeh, Hossein (Supervisor)
Abstract
The extraction of molybdenum and rhenium from acidic solution produced by pressure leaching of molybdenite concentrate, using organophosphorus solvents has been investigated. First, extraction of molybdenum by Di-2-EthyHexyl Phosphoric Acid (D2EHPA) extractant dissolved in kerosene diluents was done. Extraction experiments were designed using Taguchi L16b orthogonal array. The effects of four factors: Shaking time, Organic solvent concentration, Organic to aqueous phase ratio, pH were studied in four levels. Optimum conditions occur at: shaking time: 35 min, organic solvent concentration: 30 volumetric percent, organic to aqueous phase ratio: 3, pH: 7 and molybdenum is completely extracted....
Hydrometallurgical Extraction of Molybdenum and Rhenium from Sarcheshmeh Molybdenite Concentrates by Acidic Pressure Leaching
, Ph.D. Dissertation Sharif University of Technology ; Yoozbashizadeh, Hossein (Supervisor)
Abstract
The current study was carried out to investigate the pressure oxidative leaching of the molybdenite concentrate in nitric acid to produce molybdic oxide (technical grade) and liquor containing entire rhenium of the concentrate and molybdenum. In the first step The Taguchi method was established to design and minimize the number of experiments. By using Taguchi orthogonal (L25) array, five parameters (time, temperature, oxygen pressure, pulp density and acid concentration) in 5 levels were selected for 25 experiments. Experiments were designed and carried out in a high pressure reactor in the presence of nitric acid as solvent and oxidizing agent for the molybdenite concentrate and its ReS2...
Kinetics of pressure oxidative leaching of molybdenite concentrate by nitric acid
, Article Hydrometallurgy ; Volume 111-112, Issue 1 , January , 2012 , Pages 52-57 ; 0304386X (ISSN) ; Yoozbashizadeh, H ; Mozammel, M ; Sadrnezhaad, S. K ; Sharif University of Technology
2012
Abstract
The current study was carried out to investigate the kinetics of reactions for the pressure oxidative leaching of a molybdenite concentrate in less than one hour. The effects of oxygen pressure, stirring speed, pulp density, acid concentration and temperature on the leaching rate of the molybdenum were studied. It was found that about 85% of molybdenite was oxidized to molybdic oxide precipitate with remaining molybdenum dissolved in the leaching liquor. Analysis of experimental data showed that the reaction is chemically controlled with activation energy of 68.8 kJ/mol. Furthermore SEM images showed no significant boundary diffusion layer and it was noted that the molybdic oxide...
Application of artificial neural networks to predict pressure oxidative leaching of molybdenite concentrate in nitric acid media
, Article Mineral Processing and Extractive Metallurgy Review ; Volume 33, Issue 4 , Jul , 2012 , Pages 292-299 ; 08827508 (ISSN) ; Yoozbashizadeh, H ; Sharif University of Technology
Taylor and Francis Inc
2012
Abstract
This study is concerned with investigation of pressure oxidative leaching of entire molybdenum of a molybdenite concentrate. Effects of oxygen pressure, stirring speed, pulp density, acid concentration, and temperature on the leaching rate of molybdenum were studied. A three-layer feed-forward artificial neural network was applied to model the effect of the abovementioned parameters on the leaching ability. The leaching efficiency was considered as a target value for modeling. The quantified leaching efficiencies obtained by applying different parameters demonstrated a good agreement with neural network predictions