Variation law of gas holdup in an autoclave during the pressure leaching process by using a mixed-flow agitator

Lei Tian; Yan Liu; Jun-jie Tang; Guo-zhi L&#252;; Ting-an Zhang

doi:10.1007/s12613-017-1473-7

Volume 24 Issue 8

Aug. 2017

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Article Navigation > International Journal of Minerals, Metallurgy and Materials > 2017 > 24(8): 876-883

Lei Tian, Yan Liu, Jun-jie Tang, Guo-zhi Lü, and Ting-an Zhang, Variation law of gas holdup in an autoclave during the pressure leaching process by using a mixed-flow agitator, Int. J. Miner. Metall. Mater., 24(2017), No. 8, pp. 876-883. https://doi.org/10.1007/s12613-017-1473-7

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Lei Tian, Yan Liu, Jun-jie Tang, Guo-zhi Lü, and Ting-an Zhang, Variation law of gas holdup in an autoclave during the pressure leaching process by using a mixed-flow agitator, Int. J. Miner. Metall. Mater., 24(2017), No. 8, pp. 876-883. https://doi.org/10.1007/s12613-017-1473-7

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Research Article

Variation law of gas holdup in an autoclave during the pressure leaching process by using a mixed-flow agitator

+ Author Affiliations

Corresponding author:
Ting-an Zhang E-mail: zta2000@163.net
Received: 20 October 2016; Revised: 17 January 2017; Accepted: 17 February 2017

Abstract

Abstract

The multiphase reaction process of pressure leaching is mainly carried out in the liquid phase. Therefore, gas holdup is essential for the gas-liquid-solid phase reaction and the extraction rate of valuable metals. In this paper, a transparent quartz autoclave, a six blades disc turbine-type agitator, and a high-speed camera were used to investigate the gas holdup of the pressure leaching process. Furthermore, experiments determining the effects of agitation rate, temperature, and oxygen partial pressure on gas holdup were carried out. The results showed that when the agitation rate increased from 350 to 600 r/min, the gas holdup increased from 0.10% to 0.64%. When the temperature increased from 363 to 423 K, the gas holdup increased from 0.14% to 0.20%. When the oxygen partial pressure increased from 0.1 to 0.8 MPa, the gas holdup increased from 0.13% to 0.19%. A similar criteria relationship was established by Homogeneous Principle and Buckingham's theorem. Comprehensively, empirical equation of gas holdup was deduced on the basis of experimental data and the similarity theory, where the criterion equation was determined as ε=4.54×10^-11n^3.65P_g^0.18. It can be seen from the formula that agitation rate made the most important impact on gas holdup in the pressure leaching process using the mixed-flow agitator.
- variation law;
- autoclave;
- pressure leaching;
- gas holdup;
- mixed-flow agitator;
- empirical equation

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References

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