scholarly journals Kinetics of Chalcopyrite Leaching by Hydrogen Peroxide in Sulfuric Acid

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1173 ◽  
Author(s):  
Sokić ◽  
Marković ◽  
Stanković ◽  
Kamberović ◽  
Štrbac ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Size ◽  
Sulfuric Acid ◽  
Sulfuric Acid Concentration ◽  
Dissolution Kinetics ◽  
Poor Quality ◽  
Characterization Methods ◽  
Quantitative Light Microscopy ◽  
Chalcopyrite Concentrate ◽  
Pyrometallurgical Processing

In ores, chalcopyrite is usually associated with other sulfide minerals, such as sphalerite, galena, and pyrite, in a dispersed form, with complex mineralogical structures. Concentrates obtained by flotation of such ores are unsuitable for pyrometallurgical processing owing to their poor quality and low metal recovery. This paper presents the leaching of chalcopyrite concentrate from the location “Rudnik, Serbia”. The samples from the flotation plant were treated with hydrogen peroxide in sulfuric acid. The influences of temperature, particle size, stirring speed, as well as the concentrations of hydrogen peroxide and sulfuric acid were followed and discussed. Hence, the main objective was to optimize the relevant conditions and to determine the reaction kinetics. It was remarked that the increase in temperature, hydrogen peroxide content, and sulfuric acid concentration, as well as the decrease in particle size and stirring speed, contribute to the dissolution of chalcopyrite. The dissolution kinetics follow a model controlled by diffusion, and the lixiviant diffusion controls the rate of reaction through the sulfur layer. Finally, the main characterization methods used to corroborate the obtained results were X-ray diffraction (XRD) as well as qualitative and quantitative light microscopy of the chalcopyrite concentrate samples and the leach residue.

scholarly journals Leaching Chalcopyrite Concentrate with Oxygen and Sulfuric Acid Using a Low-Pressure Reactor

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 189 ◽  
Author(s):  
Josué Cháidez ◽  
José Parga ◽  
Jesús Valenzuela ◽  
Raúl Carrillo ◽  
Isaías Almaguer
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Oxygen Pressure ◽  
Batch Reactor ◽  
Sulfuric Acid Concentration ◽  
Low Pressure ◽  
Copper Extraction ◽  
Solid Concentration ◽  
Chalcopyrite Concentrate

This article presents a copper leaching process from chalcopyrite concentrates using a low-pressure reactor. The experiments were carried out in a 30 L batch reactor at an oxygen pressure of 1 kg/cm2 and solid concentration of 100 g/L. The temperature, particle size and initial acid concentration were varied based on a Taguchi L9 experimental design. The initial and final samples of the study were characterized by chemical analysis, X-ray diffraction and particle size distribution. The mass balance showed that 98% of copper was extracted from the chalcopyrite concentrate in 3 h under the following experimental conditions: 130 g/L of initial sulfuric acid concentration, temperature of 100 °C, oxygen pressure of 1 kg/cm2, solid concentration of 100 g/L and particle size of −105 + 75 μm. The ANOVA demonstrated that temperature had the greatest influence on copper extraction. The activation energy was 61.93 kJ/mol. The best fit to a linear correlation was the chemical reaction equation that controls the kinetics for the leaching copper from chalcopyrite. The images obtained by SEM showed evidence of shrinking in the core model with the formation of a porous elemental sulfur product layer.

scholarly journals Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate

JOM ◽  
2020 ◽  
Author(s):  
Joona Rajahalme ◽  
Siiri Perämäki ◽  
Roshan Budhathoki ◽  
Ari Väisänen
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Sulfuric Acid Concentration ◽  
Recovery Process ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Acid Consumption

AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.

scholarly journals Initial Investigation into the Leaching of Manganese from Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Foundry Slag—Part I

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 565 ◽  
Author(s):  
Norman Toro ◽  
Nelson Herrera ◽  
Jonathan Castillo ◽  
Cynthia Torres ◽  
Rossana Sepúlveda
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Acid Concentration ◽  
Room Temperature ◽  
Sulfuric Acid Concentration ◽  
Extraction Rate ◽  
Molar Ratio ◽  
Independent Variables ◽  
Initial Investigation ◽  
Optimization Methodology

In this study, the surface optimization methodology was used to assess the effect of three independent variables—time, particle size and sulfuric acid concentration—on Mn extraction from marine nodules during leaching with H2SO4 in the presence of foundry slag. The effect of the MnO2/Fe ratio and particle size (MnO2) was also investigated. The maximum Mn extraction rate was obtained when a MnO2 to Fe molar ratio of 0.5, 1 M of H2SO4, −320 + 400 Tyler mesh (−47 + 38 μm) nodule particle size and a leaching time of 30 min were used.

scholarly journals An Alternative Process for Leaching Chalcopyrite Concentrate in Nitrate-Acid-Seawater Media with Oxidant Recovery

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 518 ◽  
Author(s):  
César I. Castellón ◽  
Pía C. Hernández ◽  
Lilian Velásquez-Yévenes ◽  
María E. Taboada
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Alkaline Solution ◽  
Sodium Nitrite ◽  
Sodium Nitrate ◽  
Room Temperature ◽  
Leaching Test ◽  
Copper Concentrate ◽  
Leaching Process ◽  
Chalcopyrite Concentrate

An alternative copper concentrate leaching process using sodium nitrate and sulfuric acid diluted in seawater followed by gas scrubbing to recover the sodium nitrate has been evaluated. The work involved leaching test carried out under various condition by varying temperature, leaching time, particle size, and concentrations of NaNO3 and H2SO4. The amount of copper extracted from the chalcopyrite concentrate leached with seawater, 0.5 M of H2SO4 and 0.5 M of NaNO3 increased from 78% at room temperature to 91% at 45 °C in 96 h and 46 h of leaching, respectively. Gas scrubbing with the alkaline solution of NaOH was explored to recover part of the sodium nitrate. The dissolved salts were recovered by evaporation as sodium nitrate and sodium nitrite crystals.

scholarly journals Sustainable Hydrometallurgical Recovery of Valuable Elements from Spent Nickel–Metal Hydride HEV Batteries

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1062 ◽  
Author(s):  
Kivanc Korkmaz ◽  
Mahmood Alemrajabi ◽  
Åke Rasmuson ◽  
Kerstin Forsberg
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Hybrid Electric Vehicle ◽  
Active Material ◽  
Sulfuric Acid Concentration ◽  
Dissolution Kinetics ◽  
Leach Solution ◽  
Nickel Metal ◽  
Acid Leach ◽  
Kinetics Of

In the present study, the recovery of valuable metals from a Panasonic Prismatic Module 6.5 Ah NiMH 7.2 V plastic casing hybrid electric vehicle (HEV) battery has been investigated, processing the anode and cathode electrodes separately. The study focuses on the recovery of the most valuable compounds, i.e., nickel, cobalt and rare earth elements (REE). Most of the REE (La, Ce, Nd, Pr and Y) were found in the anode active material (33% by mass), whereas only a small amount of Y was found in the cathode material. The electrodes were leached in sulfuric acid and in hydrochloric acid, respectively, under different conditions. The results indicated that the dissolution kinetics of nickel could be slow as a result of slow dissolution kinetics of nickel oxide. At leaching in sulfuric acid, light rare earths were found to reprecipitate increasingly with increasing temperature and sulfuric acid concentration. Following the leaching, the separation of REE from the sulfuric acid leach liquor by precipitation as NaREE (SO4)2·H2O and from the hydrochloric acid leach solution as REE2(C2O4)3·xH2O were investigated. By adding sodium ions, the REE could be precipitated as NaREE (SO4)2·H2O with little loss of Co and Ni. By using a stoichiometric oxalic acid excess of 300%, the REE could be precipitated as oxalates while avoiding nickel and cobalt co-precipitation. By using nanofiltration it was possible to recover hydrochloric acid after leaching the anode material.

scholarly journals The paper-forming properties of hemp fire peroxide cellulose in combination with wood sulphate cellulose

2021 ◽  
Vol 2094 (5) ◽  
pp. 052043
Author(s):  
R A Marchenko ◽  
R Z Pen ◽  
I L Shapiro ◽  
Y A Ambrosovich
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Cannabis Sativa ◽  
Sulfuric Acid Concentration ◽  
Acid Catalyst ◽  
Strength Properties ◽  
Mixed Composition ◽  
Deciduous Wood ◽  
Sulfuric Acid Catalyst ◽  
Hardwood Pulp

Abstract Hemp fire (Cannabis sativa) was delignified with the reaction mix “acetic acid - hydrogen peroxide - sulfuric acid catalyst - water” under sulfuric acid concentration of 0.45%, liquid module of 6, and temperature of 85 ° C. The cellulose was ground to 34 … 36°SHR and mixed in different ratios in compliance with the simplex-centroid experimental design with bleached sulfate softwood and hardwood pulp. The influence of the mixed composition formulations on the main strength properties of paper castings has been studied. It has been concluded that technical cellulose obtained from hemp fire applying this method, can be used for paper products manufacturing in combination with sulphate cellulose from coniferous and deciduous wood.

Effect of Sulfuric Acid Concentration on Chalcopyrite Concentrate Chemical Leaching

2009 ◽  
Vol 71-73 ◽  
pp. 353-356
Author(s):  
Seong Jin Joe ◽  
Tadashi Chida ◽  
Masatoshi Sakoda ◽  
Hidekatsu Nakamura ◽  
Muneyuki Tamura ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Copper Extraction ◽  
H2so4 Solution ◽  
Chemical Leaching ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Chalcopyrite Concentrate ◽  
Leaching Reaction

This study reports the effect of sulfuric acid concentration on chalcopyrite chemical leaching in very simple H2SO4 solution systems ranging from 23g/L to 30g/L, with 2.5% chalcopyrite concentrate at 30°C. Copper extraction from chalcopyrite increases with an increase in sulfuric acid concentration, e.g. 86%, 90% and 92% after 96 days at 23g/L, 25/L and 27g/L H2SO4 solution respectively. Sulfur element formed on the surface of chalcopyrite was very porous as the result of an electron probe microanalyzer (EPMA). Copper extraction, however, leveled out at 35% after 20 days when the sulfuric acid concentration was higher than 28g/L on 25g/L of chalcopyrite concentrate. Sulfur element was detected by X-ray analysis as only a leaching reaction product. The passivation may be caused by thick elemental surface formed on the surface of chalcopyrite.

scholarly journals Hygroscopicity of nanoparticles produced from homogeneous nucleation in the CLOUD experiments

2016 ◽  
Vol 16 (1) ◽  
pp. 293-304 ◽  
Author(s):  
J. Kim ◽  
L. Ahlm ◽  
T. Yli-Juuti ◽  
M. Lawler ◽  
H. Keskinen ◽  
...  
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Chemical Composition ◽  
Water Uptake ◽  
Sulfuric Acid Concentration ◽  
Particle Growth ◽  
Small Mass ◽  
Initial Growth ◽  
Formation Processes ◽  
The Difference

Abstract. Sulfuric acid, amines and oxidized organics have been found to be important compounds in the nucleation and initial growth of atmospheric particles. Because of the challenges involved in determining the chemical composition of objects with very small mass, however, the properties of the freshly nucleated particles and the detailed pathways of their formation processes are still not clear. In this study, we focus on a challenging size range, i.e., particles that have grown to diameters of 10 and 15 nm following nucleation, and measure their water uptake. Water uptake is useful information for indirectly obtaining chemical composition of aerosol particles. We use a nanometer-hygroscopicity tandem differential mobility analyzer (nano-HTDMA) at subsaturated conditions (ca. 90 % relative humidity at 293 K) to measure the hygroscopicity of particles during the seventh Cosmics Leaving OUtdoor Droplets (CLOUD7) campaign performed at CERN in 2012. In CLOUD7, the hygroscopicity of nucleated nanoparticles was measured in the presence of sulfuric acid, sulfuric acid–dimethylamine, and sulfuric acid–organics derived from α-pinene oxidation. The hygroscopicity parameter κ decreased with increasing particle size, indicating decreasing acidity of particles. No clear effect of the sulfuric acid concentration on the hygroscopicity of 10 nm particles produced from sulfuric acid and dimethylamine was observed, whereas the hygroscopicity of 15 nm particles sharply decreased with decreasing sulfuric acid concentrations. In particular, when the concentration of sulfuric acid was 5.1 × 106 molecules cm−3 in the gas phase, and the dimethylamine mixing ratio was 11.8 ppt, the measured κ of 15 nm particles was 0.31 ± 0.01: close to the value reported for dimethylaminium sulfate (DMAS) (κDMAS ∼ 0.28). Furthermore, the difference in κ between sulfuric acid and sulfuric acid–imethylamine experiments increased with increasing particle size. The κ values of particles in the presence of sulfuric acid and organics were much smaller than those of particles in the presence of sulfuric acid and dimethylamine. This suggests that the organics produced from α-pinene ozonolysis play a significant role in particle growth even at 10 nm sizes.

scholarly journals PEMANFAATAN LIMBAH BATANG JAGUNG SEBAGAI ADSORBEN ALTERNATIF PADA PENGURANGAN KADAR KLORIN DALAM AIR OLAHAN (TREATED WATER)

2013 ◽  
Vol 2 (2) ◽  
pp. 1-5
Author(s):  
Fatimah Rahmayani ◽  
Siswarni MZ
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Environmental Pollution ◽  
Acid Concentration ◽  
Iodine Value ◽  
Agricultural Waste ◽  
Sulfuric Acid Concentration ◽  
Value Added ◽  
Treated Water ◽  
High Cellulose

Various result of agricultural waste that contain high cellulose can be used as an alternative adsorbent. One of them was derived from dried corn stalks which traditionally burnt after harvest that lead to environmental pollution. It is necessary to produce the value-added materials from corn stalks waste as an alternative adsorbent to reduce the level of chlorine in treated water. This process was performed by using various level of sulfuric acid concentration 1%, 3% and 5%, particles size 50 and 70 mesh in 105 oC with adsorbtion time 30, 60 and 90 minutes. The most favorable activation result was obtained at 5% concentration, with particle size 70 mesh, adsorbtion time 90 minutes and the iodine value was 482 mg/l with level of adsorbed chlorine was 96,08%. Based on this findings, we concluded that the corn stalks waste can be used as an alternative adsorbent in reducing the level of chlorine in treated water.

Sign in / Sign up

Export Citation Format

Share Document