Extraction of SiO2 from gasified rice husk carbon simultaneously rice husk activated carbon production: Restudy on product properties, activation mechanism, and evolution law of pore structure

摘要

The goal of this work was to provide a theoretical basis for efficient and harmless utilization of gasified rice husk carbon (RHC), and further understand its activation mechanism and evolution law of pore structure. K 2 CO 3 was used to extract SiO 2 from RHC, and then the rice husk activated carbon (RAC) was prepared by activating the separated rice husk activated carbon precursor (ACP). Results showed that the specific surface area of the RAC prepared via the ACP was 1006.208 m 2 /g upon the yield of SiO 2 was 20.64%. Compared with the particle size of RHC, the K 2 CO 3 mass fraction have a significant effect on the yield of SiO 2 and the K 2 CO 3 content of ACP surface The activation process of ACP mainly depended on the content of K 2 CO 3 adsorbed on its inner surface and internal structure. With an increase in K 2 CO 3 mass fraction, the pore structure of RAC roughly went through two primary stages (full development period to transitional development period). Besides, SiO 2 has a great amount of ～ 5?nm of mesopores and tended to crystallize upon sintered at 950°C for 4?h.