scholarly journals Phase Transformation and Dissolution Behavior of Pyrite in the Roasting-Sulfuric Acid Leaching Process of Vanadium-Bearing Stone Coal

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 526
Author(s):  
Xingjie Wang ◽  
Yimin Zhang ◽  
Tao Liu ◽  
Yizhong Yuan
Keyword(s):  
Inner Core ◽  
Acid Leaching ◽  
Outer Sphere ◽  
Dissolution Behavior ◽  
Iron Ions ◽  
Stone Coal ◽  
H2so4 Concentration ◽  
Leaching Process ◽  
The Difference ◽  
Leaching Condition

The selective leaching of vanadium and iron has been one of the main concerns in the field of vanadium recovery from stone coal, but the source of iron ions and their release characteristics were still unclear. In this work, the dissolution of pyrite and its roasted product, under conditions in accordance with the vanadium leaching process from stone coal by blank roasting-acid leaching, were studied. The results indicated that the leaching performances of V and Fe in stone coal were significantly correlated, with both depending on the leaching parameters of the H2SO4 concentration, the leaching temperature, the leaching time and the solid to liquid ratio. Under air conditions, with a roasting temperature of 700 °C, the roasted product of pyrite was hematite. Approximately 45% of the roasted product dissolved at its optimal leaching condition—35% higher than that of the raw pyrite. However, any further improvement was difficult, due to the difference in texture between its outer sphere and inner core. The results demonstrated that the roasting treatment led to a significant increase in the release of iron ions during the vanadium leaching process. The pre-removal of pyrite from the raw ore was necessary to reduce the concentration of iron ions in the leachate.

scholarly journals Cleaner Production of Chromium Oxide from Low Fe(II)-Chromite

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 460 ◽  
Author(s):  
Qing Zhao ◽  
Chengjun Liu ◽  
Peiyang Shi ◽  
Lifeng Sun ◽  
Maofa Jiang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Processing Parameters ◽  
Dissolution Behavior ◽  
Optimum Process ◽  
Process Conditions ◽  
Box Behnken Design ◽  
Functional Relationships ◽  
Leaching Process

Sulfuric acid-based leaching is a promising cleaner method to produce chromium salts, but its feasibility for treating low Fe(II)-chromite still remains to be proven. A Box–Behnken design (BBD)-based set of experiments for sulfuric acid leaching of low Fe(II)-chromite was utilized in this work for generating an experimental dataset for revealing the functional relationships between the processing parameters and the extraction yields of Cr and Fe. The dependent variables were found to exhibit strong intercorrelations and the models developed on the basis of statistical criteria showed excellent prediction accuracy. The optimum process conditions of leaching treatment were found to be a temperature of 176 °C, a dichromic acid/chromite mass ratio of 0.12, and a sulfuric acid concentration of 81%. Furthermore, the dissolution behavior of chromite in the leaching process and the effect of dichromic acid were experimentally investigated. It was found that the decomposition efficiency was highly dependent on the Fe(II) content of chromite, and that the dichromic acid acted both as an oxidant and a catalyst in the leaching process. On the basis of the results of this study, a novel process for treating low-Fe(II) chromite was proposed.

Comparison of direct acid leaching process and blank roasting acid leaching process in extracting vanadium from stone coal

2014 ◽  
Vol 128 ◽  
pp. 40-47 ◽  
Author(s):  
Fei Wang ◽  
Yi-Min Zhang ◽  
Tao Liu ◽  
Jing Huang ◽  
Jie Zhao ◽  
...  
Keyword(s):  
Acid Leaching ◽  
Stone Coal ◽  
Leaching Process

Calcified roasting-acid leaching process of vanadium from low-grade vanadium-containing stone coal

2014 ◽  
Vol 33 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Taiying Wang ◽  
Longjun Xu ◽  
Chenlun Liu ◽  
Zhaodi Zhang
Keyword(s):  
Acid Leaching ◽  
Low Grade ◽  
Stone Coal ◽  
Leaching Process

Direct Acid Leaching of Vanadium from Stone Coal

2017 ◽  
Vol 36 (9) ◽  
pp. 877-883 ◽  
Author(s):  
Bo Zhang ◽  
Zhaoguo Gao ◽  
Hongzhao Liu ◽  
Wei Wang ◽  
Yaohua Cao
Keyword(s):  
Sulfuric Acid ◽  
Acid Leaching ◽  
Influential Factors ◽  
Process Conditions ◽  
Stone Coal ◽  
Leaching Process ◽  
Maximum Value ◽  
Orthogonal Experiments ◽  
Counter Current ◽  
Leaching Efficiency

AbstractThis paper focused on optimizing the process conditions of direct acid leaching process to enhance the leaching efficiency of leaching vanadium from the stone coal. Orthogonal experiments and single factor experiments were conducted to investigate the effect of the influential factors of direct acid leaching on vanadium leaching ratio. The results showed that the vanadium leaching ratio reached the maximum value of 89.22 % under the optimal process conditions of CaF2 dosage 5 mass%, H2SO4 dosage 40 mass%, leaching temperature 95 °C and leaching time 10 h. Furthermore, the reaction mechanisms of the main influencing factors were analyzed. Finally, the two-stage counter-current leaching process was adopted to decrease the consumption of sulfuric acid and neutralizer, and the results indicated that the consumption of sulfuric acid decreased 12.50 % as well as neutralizer decreased 35.80 %.

Recovery of Nickel and Cobalt from Dimethyldithiocarbamate Precipitation of Pyrolusite Leaching Process

2013 ◽  
Vol 634-638 ◽  
pp. 258-262 ◽  
Author(s):  
Hai Feng Su ◽  
Bo Ji Li ◽  
Qing Lu ◽  
Yan Xuan Wen ◽  
Jing Su
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Acid Leaching ◽  
Sulfuric Acid Leaching ◽  
Leaching Process ◽  
Sulfuric Acid Medium ◽  
Cobalt Recovery ◽  
Reductive Leaching ◽  
High Nickel ◽  
Leaching Condition

Dimethyldithiocarbamate precipitation is a secondary resource containing nickel and cobalt, which are formed by adding sodium dimethyldithiocarbamate to purify the neutralized filtrate of pyrolusite reductive leaching process. The extraction of nickel and cobalt from dimethyldithiocarbamate precipitation was investigated using nitric acid as oxidant in dilute sulfuric acid medium in this paper. The effects of concentrations of nitric acid and sulfuric acid, leaching temperature as well as reaction time were discussed. The results showed that high nickel and cobalt recovery could be obtained by analyzing the leaching efficiencies of nickel and cobalt during the leaching process. The optimal leaching condition was 1.47 mol/L H2SO4 and 1.16 mol/L HNO3 for 30 min at 45 °C while using particles smaller than 0.420 mm. And the leaching efficiencies were 98% for Co and 95% for Ni, respectively.

scholarly journals Study on Ultrasonically-Enhanced Sulfuric Acid Leaching of Nickel from Nickel-Containing Residue

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 810
Author(s):  
Zhanyong Guo ◽  
Ping Guo ◽  
Guang Su ◽  
Fachuang Li
Keyword(s):  
Sulfuric Acid ◽  
Acid Leaching ◽  
Ultrasonic Waves ◽  
Sulfuric Acid Leaching ◽  
Solid Product ◽  
Leaching Process ◽  
Diffusion Controlled ◽  
Extraction Degree ◽  
Ultrasonic Conditions ◽  
Complex Nickel

In this paper, nickel-containing residue, a typical solid waste produced in the battery production process, was used to study the cavitation characteristics of ultrasonic waves in a liquid–solid reaction. The ultrasonically-enhanced leaching technology for multicomponent and complex nickel-containing residue was studied through systematic ultrasonic-conventional comparative experiments. An ultrasonic leaching kinetics model was established which provided reliable technological guidance and basic theory for the comprehensive utilization of nickel-containing residue. In the study, it was found that ultrasonically-enhanced leaching for 40 min obtained the same result as conventional leaching for 80 min, and the Ni extraction degree reached more than 95%. According to the kinetic fitting of the leaching process, it was found that the sulfuric acid leaching process belonged to the diffusion-controlled model of solid product layers under conventional and ultrasonic conditions, and the activation energy of the reaction was Ea1 = 17.74 kJ/mol and Ea2 = 5.04 kJ/mol, respectively.

Acid leaching of vanadium from roasted residue of stone coal

2010 ◽  
Vol 20 ◽  
pp. s107-s111 ◽  
Author(s):  
Yang-ge ZHU ◽  
Guo-fan ZHANG ◽  
Qi-ming FENG ◽  
Yi-ping LU ◽  
Le-ming OU ◽  
...  
Keyword(s):  
Acid Leaching ◽  
Stone Coal
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