Kinetics of Dissolution of Limestone Slurries in Sulfuric Acid

1985 ◽  
Vol 57 (10) ◽  
pp. 882-883
Author(s):  
Mario Díaz ◽  
Laureano Fonseca ◽  
José Coca
Keyword(s):  
Sulfuric Acid ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

scholarly journals Kinetics of Dissolution of Copper-Zinc Alloy in Nitric-Sulfuric Acid Solutions

2019 ◽  
pp. 214-221
Author(s):  
Natalya М. Vostrikova ◽  
Elena D. Kravtsova
Keyword(s):  
Sulfuric Acid ◽  
Noble Metals ◽  
Chemical Processes ◽  
Zinc Alloy ◽  
Acid Solutions ◽  
Copper Zinc ◽  
Kinetics Of Dissolution ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of ◽  
Base Substrate

Studies were carried out on the dissolution of a copper-zinc alloy imitating a base substrate of an electron scrap containing noble metals in nitric-sulfuric acid solutions. A mathematical model is obtained that allows calculating the rate of copper and zinc transition to nitric-sulfuric solutions by varying the concentration of H+ ions from 1 to 4 g-ion / dm3 and NO3 – ions from 0,5 to 1,0 g-ion / dm3. In the range of concentrations of H+ and NO3 – ions studied, the maximum rate of copper transition into the solution is 6,5·10–5, and zinc is 4,5·10–5 kg / m2s. The equation of regression allowing to carry out a choice of conditions for proceeding with necessary speed of the chemical processes taking place in metallurgical practice is presented

scholarly journals Mechanism, Thermodynamics and Kinetics of Rutile Leaching Process by Sulfuric Acid Reactions

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 640 ◽  
Author(s):  
Anastasiia V. Dubenko ◽  
Mykola V. Nikolenko ◽  
Eugene V. Aksenenko ◽  
Andrii Kostyniuk ◽  
Blaž Likozar
Keyword(s):  
Sulfuric Acid ◽  
Raw Materials ◽  
Bifunctional Catalyst ◽  
Chemical Transformations ◽  
Phase Component ◽  
Fluoride Ions ◽  
Thermodynamics And Kinetics ◽  
Lattice Geometry ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

Rutile decomposition by sulfuric acid, including the formation of two salts, Ti(SO4)2/TiOSO4, is thermodynamically modelled. It is shown that TiO2 can spontaneously dissolve in H2SO4 solutions. However, titania is considered as an inert (ballast) phase component of titanium-containing raw materials due to the decelerated separate nature of such chemical transformations. It is concluded that the hampered related kinetics of dissolution can be attributed to the lability of Ti(IV) cations/the specific engineered features of the hierarchical crystalline structure. It is suggested that the breaking of Ti–O–Ti bonds without additional mechanical strains in crystal lattice geometry becomes more advantageous when smaller negative anions/fluoride ions can be used. The analysis of sulfate-fluoride extraction leaching of titanium confirmed that a decrease in the Gibbs energy in the presence of F occurs. It is indicated by kinetic research studies that the addition of corrosive sodium reagent (NaF) reduces the activation by 45 kJ/mol, which results in intensification. A mechanism is proposed for the interactions involving the Ti–O–Ti cleavage on the surface/the H2SO4-induced Ti dioxide degradation on the sites of defects. Moreover, F acts as a homogeneous/heterogeneous bifunctional catalyst.

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