RESUMO
This study focuses on an improved leaching process through the combination of pressurized conditions and direct filtration of acid leaching slurry, which is conductive to improving the filterability of acid leaching systems and the extraction rates of Ti, Al, and Mg components. The effects of sulfuric acid concentration, reaction temperature, particle size of materials, acid-slag ratio, and reaction time on the leaching efficiency were systematically investigated. The results showed that pressurization significantly enhances the filtration efficiency of the reaction slurry. Under the same filtration time, the filtration efficiency increased from 46% under ordinary pressure to 78% under pressurized conditions. Moreover, under the optimal reaction conditions, the extraction rates of Ti, Al, and Mg components were more than 88.21%, 97.8%, and 96.31%, respectively. Additionally, XRD and FTIR showed that titanium oxide sulfate hydrate crystals were produced in the acid-leached residues when the reaction temperature exceeded 190 °C, thereby reducing the extraction rate of Ti component. And the XRD pattern shows that when the reaction temperature is maintained at 190 °C and the reaction time is extended to 150 min, titanium oxide sulfate hydrate crystals will be formed to reduce the extraction rate of the Ti component. In summary, this study not only provides important theoretical support for the resource utilization of high-titanium blast furnace slag but also offers a feasible solution for efficient extraction and convenient filtration, thus holding significant academic and practical implications.
RESUMO
This study proposes an innovative strategy of lignocellulose biodegradation by Inonotus obliquus under solid-state fermentation in extracting Eucommia ulmoides trans-1,4-polyisoprene (EUG) and producing reducing sugars efficiently. EUG and sugars were obtained through the white rot fungal pretreatment of E. ulmoides leaves, ultrasound-assisted solvent extraction, and enzymatic saccharification. After mere 2-day fermentation, the loss of lignin, cellulose, and hemicelluloses of the leaves achieved 7.11%, 3.47%, and 6.44%, respectively due to the high activity levels of manganese peroxidase (MnP, 973 IU g-1) and lignin peroxidase (LiP, 1341 IU g-1) produced by the fungus. The breakdown of fibrous networks brought higher yields of EUG and reducing sugars. The highest extraction yield of EUG was 4.86% from the 2-day fermented leaves, 31.4% greater than that from the control (3.69%). Meanwhile, the leaf residues after EUG extraction released 97.8 mg g-1 reducing sugars with enzymatic saccharification, 77.5% greater than that from the control (55.1 mg g-1). The results demonstrated that I. obliquus could use E. ulmoides leaves as substrate to produce high-activity-level ligninolytic enzymes in a very short time and the lignocellulose selective degradation of E. ulmoides leaves enhanced the yields of EUG and reducing sugars.