Gas holdup in pressure agitation leaching system
(Key Laboratory for ecological Metallurgy of Multimetallic Mineral, Ministry of Education, Northeastern University, Shenyang 110819, China)
Abstract: The oxidation process of the sulfide ore pressure leaching is mainly carried out in the liquid phase. Therefore, the gas holdup is essential for the gas-liquid-solid phase reaction and the extraction rate of valuable metals. In this study, the transparent quartz autoclave and high speed camera were used to investigate the mixture condition of the gas-liquid phase and the behavior of bubbles in the solution under high temperature and high pressure conditions. The results show that when the agitation rate increases from 400 r/min to 550 r/min, the gas holdup increases from 0.137% to 1.58%. When the temperature increases from 363 to 423 K, the gas holdup decreases from 1.22% to 0.774%. When the oxygen partial pressure increases from 0.2 MPa to 0.8 MPa, the gas holdup decreases from 0.997% to 0.951%. Finally, through the analysis of experimental data, the criterion equation about gas holdup is derived.
Key words: sulfide ore; pressure leaching; gas holdup; dimensional analysis; quasi-logarithmic equation