Study on kinetic of iron leaching from titanium gypsum and its cyclic acid leaching process
During the process of preparing titanium dioxide powder using sulfuric acid method,titanium dioxide waste acid and titanium gypsum are generated.A waste treatment approach is adopted,using titanium dioxide waste acid as a leaching agent to recycle and leach iron impurities from titanium gypsum,in order to achieve effective utilization of resources.The op-timum process conditions for the cyclic acid leaching of titanium gypsum with titanium white waste acid were investigated.The experimental results showed that the iron removal efficiency of titanium gypsum could reach more than 80%at reaction temperature of 333.15 K,liquid-to-solid mass ratio of 5∶1,reaction time of 60 min and two times of cyclic acid leaching.The titanium gypsum products before and after acid leaching were compared and analyzed based on SEM,XRF,XRD and other characterization results.The results showed that the acid leaching conditions could reduce the content of various impu-rity components in titanium gypsum,and the composition of the physical phase of titanium gypsum before and after acid leaching was CaSO4·2H2O.On the basis of the above research,the complete titanium gypsum treatment process was formed.The leaching characteristics of elemental iron in titanium gypsum under the titanium dioxide waste acid system were investi-gated,and fitted and calculated using a leaching kinetic model.The results showed that the leaching process was controlled by internal diffusion and the apparent activation energy of the reaction was 59.08 kJ/mol.
titanium gypsumtitanium dioxide waste acidleaching kineticactivation energy
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NSTL
万方数据
维普
