Kinetics of dissolution of Mardin-Mazıdaği (Turkey) phosphate ore in dilute phosphoric acid solutions

2010 ◽  
Vol 27 (2) ◽  
pp. 110-115 ◽  
Author(s):  
M. Sınırkaya ◽  
A. K. Özer ◽  
M. S. Gulaboglu
Keyword(s):  
Phosphoric Acid ◽  
Acid Solutions ◽  
Phosphate Ore ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

The Dissolution Kinetics of Tincal in Phosphoric Acid Solutions

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuksel Abali ◽  
Salih U Bayca ◽  
Ayse E Guler
Keyword(s):  
Particle Size ◽  
Phosphoric Acid ◽  
Dissolution Rate ◽  
Acid Concentration ◽  
Reaction Temperature ◽  
Dissolution Kinetics ◽  
Reaction Model ◽  
Acid Solutions ◽  
Liquid Ratio ◽  
Kinetics Of

In this study, the dissolution kinetics of tincal in phosphoric acid solutions was investigated. The effects of reaction temperature, acid concentration, solid to liquid ratio, particle size and stirring speed were determined in the experiments. The results showed that the dissolution rate increased with increasing acid concentration, reaction temperature, stirring speed and increased with decreasing particle size and solid to liquid ratio. The dissolution rate was found to be based on the first order pseudo homogenous reaction model. The activation energy of the tincal in phosphoric acid solution was determined as 42.28 kJ.mol-1.

scholarly journals Kinetics of pyrite oxidation by hydrogen peroxide in phosphoric acid solutions

1999 ◽  
Vol 64 (12) ◽  
pp. 753-764 ◽  
Author(s):  
Mile Dimitrijevic ◽  
Milan Antonijevic ◽  
Valentina Dimitrijevic
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphoric Acid ◽  
Pyrite Oxidation ◽  
Negative Influence ◽  
Acid Solutions ◽  
Phosphate Ion ◽  
Shrinking Core ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Oxidation By Hydrogen Peroxide

The kinetics of pyrite oxidation by hydrogen peroxide in phosphoric acid solutions were investigated. The effects of stirring, temperature, and particle size, as well as of the hydrogen peroxide and phosphoric acid concentrations were studied. The effect of phosphate ion addition was also examined. The oxidation kinetics was found to follow a shrinking core model, with the surface chemical reaciton as the rate-controlling step. This is in accord with an activation energy of 57 kJ/mol and a linear relationship between the rate constant and the reciprocal of the particle radius. The reaction order with respect to the hydrogen peroxide concentration was found to be equal to unity. Variation of the phosphoric acid concentration had practically no effect on the rate of pyrite oxidation. Addition of the phosphate ion in the relatively low concentration range (0.005.0.1 mol/dm 3) had a highly negative influence on the rate of pyrite oxidation, indicating that this ion has an inhibiting effect on the oxidation of pyrite by hydrogen peroxide.

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

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