Junqiang Zhang,Xuzhong Gong,Zhi Wang,Junhao Liu,Yanguang Chen,Dong Wang,Guoyu Qian,Chuan Wang
Various factors affecting the high temperature compressive strength (TCS) for the carbide slag-based CaO pellets were systematically examined both experimentally and theoretically. It showed that the spherical CaO particles with microstructure can enhance the TCS of the pellets, and the higher the spheroidization of the particles, the higher the TCS. Inducing H 3 BO 3 can lead to a low-temperature nucleation of CaO particle, inhibit the growth of CaO grain, and thus form spherical CaO particles. The TCS of CaO pellet from Ca(OH) 2 was optimized with the response surface methodology with a highest value of 37.4 MPa. For the CaO pellet from the carbide slag, the TCS under optimal conditions was 39.67 MPa. However, it was found out that an excess of H 3 BO 3 inducer in the CaO pellets from the carbide slag could produce eutectic calcium borate with a low melting point, resulting in a decreased TCS.
Metal-organic frameworks (MOFs) are a promising material for CO 2 adsorption because of their great specific surface area, well-ordered porous structures ordered porous structure and various means available for functionalization. In this work, the calcium squarate (UTSA-280) was synthesized from carbide slag without pretreatment at room temperature by a rapid mechanochemical method, and then was further functionalized with tetraethylenepentamine (TEPA) to prepare CO 2 adsorbents. The effects of water content, ball milling frequency, adsorption temperature, and TEPA loading on CO 2 adsorption performance of various adsorbents were investigated. The results showed that the CO 2 adsorption of the synthesized MOFs increased firstly and then decreased with increasing water content and ball milling frequency. The synthesized MOFs with water content of 300 mmol and ball milling frequency of 15 HZ exhibited the best crystallinity. The addition of TEPA provided additional adsorption sites and led to the increase of CO 2 adsorption capacity. The UTSA-280–300-15-40TEPA demonstrated the highest CO 2 adsorption capacity (2.89 mmol/g) at 25 °C. The CO 2 adsorption kinetics analysis showed that the Avrami model fitted well with the experimental results. Furthermore, the UTSA-280–300-15-40TEPA exhibited excellent chemical stability during the adsorption–desorption cycles, with only a 14.53 % decrease in adsorption capacity after 10 cycles. This work demonstrated the possibility of preparing UTSA-280 using carbide slag for effective CO 2 adsorption.