Sulfuric acid leaching kinetics of South African chromite

The kinetics of the sulfuric acid leaching of altered ilmenite, mechanisms, and process intensification methods were studied. The effect of changing the chemical composition during grinding was determined. The content of ilmenite and pseudorutile decreased from 5.3% to 3.1% and from 90.2% to 63.1%, respectively. Rutile increased from 4.5% to 28.7%, while a pseudobrookite new phase appeared in the amount of 5.1% after 2 h of grinding. It was found that the modification of raw material by sulfuric acid led to the increase of the decomposition rate, and at the same time, decreased when the ore was utilized due to an increase of insoluble TiO2 content. Isothermal conditions were evaluated with H2SO4 concentration varying from 50 to 96%. The data obtained were described with the approximation of the contracting sphere model. It was shown for the first time that H2SO4 > 85 wt% causes a sharp constant decrease of titanium. Correlating these phenomena allows for the consideration of H2SO4·H2O as reagents, rather than H2SO4 molecules. It was experimentally proven that at a temperature above 190 °C, the Ti leaching degree dropped, which is explained by the formation of polymerized TiOSO4. Finally, it was shown that adding NaF reduced the activation energy to 45 kJ/mol.

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Kinetics of sulfuric acid leaching of low-grade zinc silicate ore

Hydrometallurgy ◽

10.1016/s0304-386x(00)00059-1 ◽

2000 ◽

Vol 55 (3) ◽

pp. 247-254 ◽

Cited By ~ 133

Author(s):

E.A Abdel-Aal

Keyword(s):

Sulfuric Acid ◽

Acid Leaching ◽

Zinc Silicate ◽

Low Grade ◽

Sulfuric Acid Leaching ◽

Kinetics Of

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Dissolution kinetics of vanadium from black shale by activated sulfuric acid leaching in atmosphere pressure

International Journal of Mineral Processing ◽

10.1016/j.minpro.2015.03.005 ◽

2015 ◽

Vol 138 ◽

pp. 1-5 ◽

Cited By ~ 14

Author(s):

Zhong-Jun Ju ◽

Cheng-Yan Wang ◽

Fei Yin

Keyword(s):

Sulfuric Acid ◽

Black Shale ◽

Acid Leaching ◽

Dissolution Kinetics ◽

Sulfuric Acid Leaching ◽

Atmosphere Pressure ◽

Kinetics Of

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KINETIC REGULARITIES OF NICKEL SULFURIC ACID LEACHING PROCESSES

Вестник Тверского государственного университета. Серия: Химия ◽

10.26456/vtchem2021.3.9 ◽

2021 ◽

pp. 73-78

Author(s):

Анна Игоревна Пичугина ◽

Дарья Дмитриевна Гончар

Keyword(s):

Sulfuric Acid ◽

Acid Leaching ◽

Rotation Frequency ◽

Metal Extraction ◽

Sulfuric Acid Leaching ◽

Disk Rotation ◽

Natural Minerals ◽

Composition And Structure ◽

Polynomial Models ◽

Kinetics Of

В работе представлены результаты исследования кинетики сернокислого выщелачивания никеля из его сульфидов. В качестве модельных образцов выбраны синтезированные сульфиды никеля по составу и строению идентичные природным минералам: миллериту и хизлевудиту. Получены зависимости влияния скорости извлечения металла от концентрации серной кислоты, температуры, частоты вращения диска и продолжительности взаимодействия. Рассчитаны полиномиальные модели изучаемого процесса, преобразованные в уравнения скорости. Вычислены константы скорости и эмпирические значения энергии активации. The paper presents the results of a study of the kinetics of sulfuric acid leaching of nickel from its sulfides. Synthesized nickel sulfides were selected as model samples, identical in composition and structure to natural minerals: millerite and heazlewudite. The dependences of the influence of the metal extraction rate on the concentration of sulfuric acid, temperature, disk rotation frequency and duration of interaction are obtained. The polynomial models of the process under study, transformed into velocity equations, are calculated. The rate constants and empirical values of the activation energy are calculated.

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